Bibliothek

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • 2010-2014
  • 2005-2009
  • 1995-1999  (174)
  • 1990-1994  (335)
  • 1890-1899
  • 1820-1829
  • 2008
  • 1996  (174)
  • 1994  (335)
  • 1967
  • 1966
  • 1894
  • Conference proceedings
  • Immunohistochemistry
Materialart
Erscheinungszeitraum
  • 2010-2014
  • 2005-2009
  • 1995-1999  (174)
  • 1990-1994  (335)
  • 1890-1899
  • +
Jahr
  • 1
    ISSN: 1530-0358
    Schlagwort(e): p53 ; Colorectal adenoma ; Colorectal carcinoma ; Adenoma-carcinoma sequence ; Dysplasia ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract PURPOSE: To clarify the relation between tumor-suppressor gene p53 expression and histologic grades of dysplasia in colorectal adenomas, we performed immunohistochemical analysis in a series of 59 colorectal polyps and 40 advanced carcinomas. METHODS: Adenomatous polyps were stained by hematoxylin and eosin and classified into mild, moderate, and severe dysplasia (intramucosal carcinoma), according to the World Health Organization's classification. RESULTS: p53 was positive in 7.1 percent (2/28) of mild, 29.4 percent (5/17) of moderate, and 62.5 percent (5/8) of severe dysplasia. In submucosal and advanced carcinomas, positivity rates were 75 percent (3/4) and 47.5 percent (19/40), respectively. Different staining patterns were found, according to grades of dysplasia. In the adenomas with mild or moderate dysplasia, a few focal crypts showed localized p53-positive staining. Adenomas with severe dysplasia had two different staining types. One was a focal staining type as shown in mild or moderate dysplasia; the other was a diffuse staining type, in which glands with mild or moderate dysplasia, surrounding severe dysplasia area, were also stained. Submucosal and advanced carcinomas showed a strong positive staining in cancer cells only. CONCLUSIONS: Overexpression of p53 protein in adenomas with mild or moderate dysplasia and existence of two types of expression in adenomas with severe dysplasia were observed. These facts suggested the possible existence of different pathways in the adenoma to carcinoma progression.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1438-8359
    Schlagwort(e): Parvalbumin ; Calbindin D-28k ; Calretinin ; Spinal cord ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The effect of noxious stimulation on the immunore-activity of the calcium-binding proteins parvalbumin (PV), calbindin-D-28k (CB) and calretinin (CR) was investigated in the superficial dorsal horn of lumbar levels L5-L3 of the rat spinal cord. Freund's adjuvant was injected unilaterally into the hindpaw to induce inflammation. Immunohistochemical techniques were utilized to investigate changes in the calcium-binding proteins 2h and 1, 2, 4, and 7 days after injection. At 24h after injection, a decrease in the intensity of fluorescence of PV-immunoreactive (IR) fibers was observed in the superficial layer (substantia gelatinosa) of the ipsilateral dorsal horn (L5-L3) in most animals. Comparatively fewer animals exhibited changes in the CB- and CR-IR fibers, except at the L3 level 2 days after, and at the L4 level 7 days after the hindpaw injection. After the peak response, at 24h in most animals, there was a decline in the number of responders at 2 days and no differences were noted at 4 days. However, at 7 days, there was again an increase in the number of animals revealing diminished fluorescence intensity in the ipsilateral substantia gelatinosa. Changes in immunoreactivity of calcium binding proteins in the interneurons of the superficial lumbar dorsal horn may reflect hyperactivity within these neurons following noxious stimulation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    Springer
    International journal of legal medicine 109 (1996), S. 10-13 
    ISSN: 1437-1596
    Schlagwort(e): Oestrogen receptor ; Vaginal epithelium ; Immunohistochemistry ; Forensic value
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin , Rechtswissenschaft
    Notizen: Abstract This study investigated whether oestrogen receptors can be immunohistochemically detected in paraffin-embedded vaginal mucosa samples using monoclonal antibodies and whether the method would be suitable for the identification of vaginal cells in cytological smears. Samples of vaginal mucosa were obtained from living females and female corpses, as vaginal smears. For comparison purposes, resected prepuce samples and samples of postmortem male urethral mucosa were also investigated. Nuclear oestrogen receptors could be regularly detected in the basal, parabasal and deeper intermediate epithelium layers of freshly fixed vaginal mucosa but proved to be highly sensitive to autolytic changes. In the cytological smears obtained from living subjects, no oestrogen receptors were detectable. Oestrogen receptors were also detected in the basal epidermal cells of the male prepuce.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    ISSN: 1432-1351
    Schlagwort(e): Neurotransmitter ; Mutants ; Immunohistochemistry ; Behavior ; Insecta
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The role of histamine as a fast neuro-transmitter of imaginai insect photoreceptors is firmly established. In adult Drosophila, histamine is also found in mechanosensory receptors of cuticular hair sensilla and in a small number of nonreceptor neurons in head and body ganglia. Here we investigate the function of histamine by immunohistochemical and behavioral analysis of mutants deficient in the hdc gene that codes for histidine decarboxylase. The allele hdc JK910 appears to be a null mutation, as histamine immunoreactivity is almost entirely eliminated. Homozygous flies are blind in various behavioral paradigms. Mutant larvae, on the other hand, show normal photokinetic responses. Thus, adult Drosophila photoreceptors most likely utilize only a single substance, histamine, as a neurotransmitter, whereas larval photoreceptors apparently employ a different transmitter. With the alleles hdc p211 , hdc p217 , and hdc p218 , variable amounts of histamine are found in photoreceptors and mechanoreceptors, but no histamine could be detected in any of the nonreceptor neurons. These mutants show various degrees of visual and mechanosensory impairment, as determined by quantitative behavioral assays. We conclude that histamine is required for normal function of cuticular hair sensilla and for efficient grooming of the body surface. Thus, in Drosophila, histamine represents a major functional neurotransmitter for mechanosensory receptors.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Comparative clinical pathology 6 (1996), S. 214-220 
    ISSN: 1433-2981
    Schlagwort(e): Rat ; Blood-brain barrier ; Development ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract A mouse monoclonal antibody which specifically reacts with putative blood-brain barrier (BBB) competent endothelial cells of rat cerebral capillaries was used to identify barrier competent cells in the central nervous system (CNS). The development of the cerebral capillaries and the BBB was examined and quantified, from day 6 to day 40 postpartum, using immunocytochemical and unbiased stereological techniques. There was a progressive increase in capillary formation postnatally, with collateral branching observed with progressive age. BBB development was confined to individual endothelial cells located at the periphery of the cortex until day 10 postpartum. Antibody binding progressively increased postnatally, contributing 30% of the total capillary surface area by day 20. There was a rapid elevation of reactivity from day 20 to day 40, with a mean of 83% by day 40. The BBB constitutes minimal amounts of brain vascular capillaries before day 10 of life in the rat. There is a slower increase in BBB than in total capillaries between days 10 and 20. There is a reversal of this trend between days 20 and 40.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    Springer
    International journal of legal medicine 108 (1996), S. 210-214 
    ISSN: 1437-1596
    Schlagwort(e): Amniotic fluid embolism ; Syncytiotrophoblastic cells ; Megakaryocytes ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin , Rechtswissenschaft
    Notizen: Abstract The histological diagnosis of amniotic fluid embolism (AFE) is based on finding amniotic fluid components in the pulmonary microvasculature. In addition to the distinctive constituents of AFE, placental and decidual tissue fragments as well as isolated trophoblastic cells and megakaryocytes are potentially detectable within pulmonary vessels. The identification of single syncytiotrophoblastic cells (STC), and their differentiation from circulating megakaryocytes (MK) within the lumen of small and medium-sized pulmonary vessels is difficult by classical morphological methods. In a fatal case of AFE, we have successfully detected the simultaneous presence of STC and MK in the pulmonary microvasculature by means of a panel of specific monoclonal (CD61-GpIIIa, β-hCG) and polyclonal (FVIII-vW hPL) antibodies. The immunohistochemical analysis for identification of STC and MK should provide more precise data on their incidence and distribution in physiological and pathological conditions as well providing new insights into their physiopathological implications and their correlation with AFE and other gynaecological complications.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Pediatric surgery international 11 (1996), S. 126-129 
    ISSN: 1437-9813
    Schlagwort(e): Biliary atresia ; Intrahepatic bile ducts ; Proliferating cell nuclear antigen ; Transforming growth factor α ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Proliferating cell nuclear antigen (PCNA) and transforming growth factor α (TGFα) are considered as markers of cell proliferation. The expression of PCNA and TGFα was evaluated immunohistochemically using anti-PCNA antibody and TGFα in 31 patients with biliary atresia (BA) (15 jaundice-free and 16 with persistent jaundice) and 6 control infants. The labeling indices (LI) for PCNA- and TGFα-positive bile-duct epithelium in BA were 14.1±14.0% and 51.4±33.7%, respectively, which was significantly higher than in the controls (P 〈0.01). In BA, the number of PCNA-immunoreactive cells was higher in the peripheral bile ductules than in the central bile ducts of the portal tract (P 〈0.01). LI was not related to patient age at the time of hepatic portoenterostomy in two groups divided at the age of 60 days. Patients in the persistent jaundice group had greater expression of PCNA and TGFα (21.7±16.0% and 76.9±20.7%, respectively) compared to those in the jaundice-free group (6.0±2.7% and 24.3±20.9%, P 〈0.001). PCNA and TGFα expression in the bile-duct epithelium of the portal tract was closely related to prognosis in BA patients, and thus could be useful as a prognostic marker.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Pediatric surgery international 11 (1996), S. 33-40 
    ISSN: 1437-9813
    Schlagwort(e): Immunohistochemistry ; Human ; Vasoactive intestinal polypeptide ; Somatostatin ; Neuropeptide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The pathophysiology of the impaired sphincter function in Hirschsprung's disease is still unclear. The peptidergic innervation of the aganglionic large intestine is known to be disturbed. The present study analyzes the peptidergic innervation of the aganglionic internal anal sphincter (IAS) in comparison with that of the circular layer of ganglionic and aganglionic large intestine. Immunoreactivity for the following substances was analyzed: vasoactive intestinal polypeptide (VIP), substance P (SP), met-enkephalin (ENK), calcitonin gene-related peptide (CGRP), somatostatin (SOM), and neuropeptide Y (NPY). All patients were operated upon with Soave's endorectal pull-through technique and a posterior partial myectomy of the IAS. For comparison, specimens of resected IAS from adult patients operated upon for rectal cancer as well as autopsy specimens from a 2-year-old child were analyzed. Differences in the density of nerve fibers between the ganglionic and aganglionic large intestine were in accordance with previous studies. In sections of normoganglionic IAS moderately dense networks of nerve fibers immunoreactive for NPY, SOM, and VIP were observed. The occurrence of NPY and SOM was somewhat more frequent here compared to the colonic circular muscle coat, whereas the opposite was seen for VIP. In aganglionic IAS abundant nerve fibers immunoreactive for NPY, SOM, and VIP were observed. Only a few SP-, CGRP-, and ENK-immunoreactive fibers were found in normal and aganglionic IAS. It is concluded that there were moderate differences in the peptidergic innervation of the aganglionic IAS as compared to the normal ganglionic IAS and the circular muscle coat of the ganglionic and aganglionic large intestine.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    ISSN: 1432-2161
    Schlagwort(e): Key words Osteonectin ; Osteosarcoma ; In situ hybridization ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Thirty-three osteosarcomas at various grades of histologic differentiation, including chondroblastic, osteoblastic, and fibroblastic variants, were investigated immunohistochemically for evidence of osteonectin. Twenty-two cases of varying types of osteosarcoma were examined with in situ hybridization for mRNA expression of osteonectin. Immunohistochemically, osteonectin was present in all the osteosarcomas in this study. With in situ hybridization, 12 out of 22 osteosarcomas showed a positive signal. Two osteochondrosarcomas, seven chondrosarcomas, and one mesenchymal chondrosarcoma were also studied with regard to the localization of osteonectin, either immunohistochemically or by in situ hybridization. Immunohistochemically, osteonectin was present in all the chondroid lesions except for one osteochondroma. However, in situ hybridization of osteonectin mRNA was negative in all the chondroid lesions we studied. This study revealed that immunohistochemical localization of osteonectin is not useful in providing conclusive diagnosis of osteosarcoma. In situ hybridization of osteonectin mRNA might be useful in differentiating osteosarcoma from nonosteogenic bone tumors.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 25 (1996), S. 302-304 
    ISSN: 1432-2161
    Schlagwort(e): Key words Ewing’s sarcoma ; Sacrum ; Lytic lesion ; CT-guided needle biopsy ; Cytology ; Immunohistochemistry ; PAS ; NSE ; O13
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A lytic lesion with soft-tissue extension in the sacrum of a 47-year-old man was needle-biopsied under computed tomographic (CT) guidance using an 18-gauge cutting needle. The cytologic appearance of the lesion and immunohistochemical staining were diagnostic of Ewing’s sarcoma. Specifically, a new marker (O13) for the presence of glycoprotein p30/32 mic2 in Ewing’s sarcoma was utilized.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 11
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 428 (1996), S. 85-89 
    ISSN: 1432-2307
    Schlagwort(e): Nm23/NDP kinase ; Cathepsin D ; Immunohistochemistry ; Anal carcinoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Reduced expression of nm23/NDP kinase and increased expression of cathepsin D seem to be correlated with a high metastatic potential for a variety of malignancies. Nm23/NDP kinase and cathepsin D have been correlated with several clinical variables, including survival in 96 patients with squamous cell carcinoma of the anal canal. Immunohistochemical methods were used on paraffin-embedded biopsies. Seventy-six (79%) anal carcinomas were nm23/NDP kinase positive, whereas 35 (36%) and 28 (29%) of the cases were cathepsin D positive in tumour cells and stromal cells, respectively. We have found no indication that the extent of cathepsin D staining has any prognostic significance. The overall survival of patients with tumours positive for nm23/NDP kinase in the cytoplasm was significantly shorter than that of patients with anal carcinomas negative for nm23/NDP kinase.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 428 (1996), S. 159-163 
    ISSN: 1432-2307
    Schlagwort(e): Cyclin D3 ; Immunohistochemistry ; Pulmonary carcinoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Cyclin D3, a cell cycle regulator, is encoded in the 6q21 chromosome region. Abnormalities of this gene and its protein product have not been found in normal tissues or in malignancies from human subjects. The expression of cyclin D3 was studied immunohistochemically in archival formalin-fixed, paraffin-embedded specimens from normal organs obtained from three autopsy cases and 237 human primary pulmonary carcinomas. In normal organs, nuclear positivity for cyclin D3 was observed in reactive type-2 pneumocytes, islets of Langerhans, lymphocytes from lymph nodes, superficial cells of transitional epithelium, epithelium of oesophagus, stomach, small intestine and gallbladder, endothelium, smooth muscles, and brain. Proliferating cells such as lymphocytes in the germinal centres and non-proliferating cells such as neurons both demonstrated cyclin D3 immunoreactivity. Cyclin D3 showed obvious nuclear immunoreactivity in 168 pulmonary carcinomas (71%). The proportion of tumour cells that were cyclin D3-positive ranged from 1% to 73% (median, 16%). There was no relationship between cyclin D3 immunoreactivity and histological typing, tumour differentiation, or pathological TNM staging. In pulmonary carcinomas, distinct expression of the cyclin D3 protein is unlikely to be implicated in tumorigenesis, because of its expression in only a small fraction of cancer cells. It may relate to cancer progression. The distribution of cyclin D3 reactivity in the normal tissues suggests that cyclin D3 affects other processes than cell cycle regulation in a lineage-specific manner.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 13
    ISSN: 1432-2307
    Schlagwort(e): Immunohistochemistry ; Melanocytic markers ; Paget's disease ; Melanoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract A comparative immunohistochemical study was performed on Paget's disease of the nipple (PDN), extramammary Paget's disease (EMPD) and cutaneous superficial spreading melanoma (SSM) using antibodies to S100, NK1-C3 and HMB45, cytokeratin (CAM 5.2) and c-erb B2 oncoprotein (21N). Conventional histochemical stains for intracytoplasmic mucin and melanin were also done. Of the 20 cases of PDN, positivity was seen in 12 with S100, 16 with NK1-C3, none with HMB45, 20 with CAM 5.2 and 19 with 21N. All 5 cases of EMPD were CAM 5.2 positive and HMB45, S100 and 21N negative. Three EMPD were NK1-C3 positive. All 10 cases of SSM were S100, NK1-C3 and HMB45 positive and all were CAM5.2 and 21N negative. Mucin was demonstrable in 11 cases of PDN and all of EMPD but none of SSM. Melanin was seen in 2 PDN, 3 EMPD and all SSM cases. Identification of mucin and melanin, therefore, proved an unreliable means of distinguishing these diseases. Immunohistochemistry for cytokeratin and HMB45 appear to be the most specific markers in differentiating Paget's disease and SSM. Antibodies to c-erb B2 may also be valuable in this situation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 14
    ISSN: 1432-2307
    Schlagwort(e): Langerhans cell histiocytosis ; HECA-452 ; Sialyl-Lex/sialyl-Lea ; Homing mechanisms ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The cutaneous lymphocyte associated antigen (CLA) recognized by the monoclonal antibody (moAb) HECA-452 plays a major role in the homing of lymphocyte subpopulations to the skin by binding to E-selectin on dermal microvessels. The factors responsible for the immigration of Langerhans cells (LC) and their precursors into the skin are still unknown, but because normal resting LC are also capable of expressing CLA, the antigen was proposed as a candidate LC-homing structure. To gain insight into these mechanisms, the expression of HECA-452 on neoplastic LC within and outside the skin was investigated in paraffin-embedded sections from 44 patients with localized and disseminated forms of Langerhans cell histiocytosis (LCH) presenting with proliferating cells positive for CD45, CD1a, S100 and HLADR. Irrespective of the clinical presentation or the type of organ involved, HECA-452-positive LC were detected in all biopsies tested (range 5-〉90%). The most prominent HECA-452 reactivity was observed in skin lesions and in areas with accumulations of eosinophilic granulocytes. Our data provide evidence for a heterogeneous expression of sLex/sLea structures in various stages of activated and/or differentiated LCH cells. Remarkably, CLA-antigen expression on LCH-cells was not restricted to cutaneous sites. In view of recent findings on the expression of HECA-452 on resting epidermal LC, our data are compatible with the view that local cytokine production by keratinocytes or cells from the surrounding infiltrate induce and/or modulate CLA expression on LC in both cutaneous and extra-cutaneous sites.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 15
    ISSN: 1432-2307
    Schlagwort(e): Interstitial nephritis ; Tubulitis ; Phenotype ; Immunohistochemistry ; Prognosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The prognostic impact of tubulitis and the phenotype of the infiltrating cells in the tubules were studied in ten percutaneous renal biopsies from six patients with acute tubulointerstitial nephritis (ATIN). The inflammatory cell subsets in the tubules and interstitium (CD3+, CD4+, CD8+, CD20+, CD45RO+, CD56+, CD57+, CD68+ and TIA-1+ cells), the expression of vimentin and the proliferation-associated antigen Ki-67 by cortical tubular cells, and the grade of tubulitis, interstitial infiltration and fibrosis were analysed. Cytotoxic injury to tubular cells in the vicinity of tubular-wall-localized lymphocytes was studied ultrastructurally. ATIN was drug-induced in three patients, related to Legionella infection in two and idiopathic in one patient. Four patients recovered, one with reduced renal function. Two patients developed end-stage renal disease. CD8+ and CD4+ lymphocytes, and a smaller number of macrophages, infiltrated the tubules. The predominant lymphocyte subset in the tubules was the same as in the interstitium. Cytotoxic injury to tubular cells was not seen electron microscopically. The tubular cells exhibited increased proliferative activity and expressed vimentin, indicating non-specific tubular damage. The cell subset, the severity of tubulitis, and the tubular expression of vimentin were not related to outcome. the main prognostic factor was the severity of the interstitial fibrosis. Tubulitis in ATIN may be a harmless non-immune reaction, mediated by tubular expression of cytokines, together with adhesion and other molecules.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 16
    ISSN: 1432-2307
    Schlagwort(e): Non-small-cell lung carcinoma ; Immunohistochemistry ; Intercellular adhesion molecules ; ICAM-1 (CD54) ; Vascular cell adhesion molecule ; VCAM-1 ; E-selectin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Vascular cell adhesion molecules (VCAM) play an important part in the regulation of inflammation and are considered to be important in the process of malignant tumour growth. The present study describes the immunohistochemical staining patterns of E-selectin, intercellular adhesion molecule (ICAM)-1 and VCAM-1 on endothelial cells of the vessels in tumour stroma and other cell types in non-small-cell lung carcinoma (NSCLC; n=43) in association with inflammatory cells. Expression of E-selectin was dominant on endothelial cells in the stromal areas of the tumour, especially at the borders, and was confined to endothelial cells. Moderate to strong staining for ICAM-1 was demonstrated on endothelial cells irrespective of size or localization of the vessels. Compared with ICAM-1, fewer vessels were positive for VCAM-1, and stained with lesser intensity. ICAM-1 expression was demonstrated on NSCLC cells, the basal cells of bronchial epithelium, type II pneumocytes, lymphocytes and fibroblasts. VCAM-1 was clearly expressed on NSCLC cells in 4 of the 43 cases and on lymphocytes and fibroblasts. The staining patterns observed on endothelial cells support the idea of an active status of NSCLC vessels. This phenotypic pattern looks similar to the vascular component of inflammation. The presence of ICAM-1 and VCAM-1 on NSCLC cells suggests a functional role in the process of chemotaxis for tumour cells.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 17
    ISSN: 1432-2307
    Schlagwort(e): Cyclin E ; Colorectal adenoma ; Colorectal carcinoma ; Immunohistochemistry ; Ki-67 ; p53
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The expression of cyclin E in human colorectal adenomas and adenocarcinomas was examined immunohistochemically to elucidate the role of cyclin E in the colorectal carcinogenesis. The expression of cyclin E was detected in 25% (91/358) of the adenomas and 56% (149/267) of the adenocarcinomas. The incidence of strongly positive cases was significantly higher in the adenocarcinomas (20%) than in the adenomas (5%) (P〈0.01). Among adenomas, a significant correlation was noticed between the expression of cyclin E and the grade of atypia. The incidence of cyclin E expression was significantly higher in the adenocarcinomas without an adenoma component (62%; 104/169) than in those with this component (46%; 45/98) (P〈0.05). Furthermore, the incidence of the cyclin E expression was higher in stages 1 and 2 carcinoma than in stage 0 and stages 3 and 4 carcinoma. The expression of cyclin E was the most prominent in tumors invading the submucosa and muscularis propria. The expression of cyclin E was significantly correlated with the proliferative activity of the tumor cells measured by Ki-67 antigen expression (P〈0.01). It was also correlated with the expression of p53 protein in the tumor cells (P〈0.01). Overexpression of cyclin E and subsequent deregulation of cell cycle may contribute to the development and early progression of the colorectal carcinomas.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 18
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 429 (1996), S. 185-188 
    ISSN: 1432-2307
    Schlagwort(e): Choriocarcinoma ; Placenta ; In situ ; Flow cytometry ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Two cases of choriocarcinoma in situ arising in a first trimester placenta are reported in a 28-year-old gravida 2, para 1, Japanese woman and a 38-year-old gravida 2, para 0. Both had a dilation and curettage (D and C) for vaginal bleeding and the absence of intrauterine fetus. No macroscopic abnormalities were noted in either case. However, histologically, localized nodules of neoplastic trophoblastic proliferation measuring 5 mm in the first case, and 6 mm in the second appeared to arise directly from normal stem villi and project into the intervillous space. Both tumours were composed of biphasic cytotrophoblast and syncytiotrophoblast. Fetal elements were not observed in either case. Radiographic studies showed no metastatic lesions in either patient. Urinary human chorionic gonadotropin levels were within normal range in both patients. The first patient had a normal full-term spontaneous vaginal delivery 22 months after the D and C and was free from disease without therapy at 32 months. The second patient was free from disease without therapy with a limited follow-up. These tumours provide evidence for an origin of choriocarcinoma from trophoblast of a stem villus. This report illustrates the need to perform thorough microscopic examination of the products of conception especially in the absence of a fetus or fetal parts.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 19
    ISSN: 1432-2307
    Schlagwort(e): Pancreatic adenocarcinoma ; CD44s ; CD44v6 ; Immunohistochemistry ; Metastasis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Alternative splicing gives rise to numerous CD44 isoforms, some of which seem to have a role in tumour metastasis. Specifically, a variant form of CD44 with sequences encoded by exon v6 (CD44v6) confers metastatic potential when transfected into a nonmetastasizing cell line of rat pancreatic adenocarcinoma. This study has investigated standard CD44 (CD44s) and CD44v6 expression immunohistochemically in 6 samples of normal pancreatic tissue, 4 of tissue affected by chronic pancreatitis, and 24 of tissue from metastasizing and nonmetastasizing pancreatic adenocarcinomas. In addition, 18 samples from lymph node or visceral metastases were included in the study. CD44s was expressed in nonneoplastic tissue and in tissue from pancreatic adenocarcinomas. In contrast, CD44v6 was not detected in any of the normal tissue or chronic pancreatitis specimens, whereas 54% of pancreatic adenocarcinomas and 55% of metastases expressed this variant exon. Although it is not clear whether CD44 isoforms containing exon v6 play a part in malignant progression in the human exocrine pancreas, it seems plausible that the expression of multiple isoforms containing this and other variant exon confers a selective advantage on pancreatic adenocarcinoma.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 429 (1996), S. 213-219 
    ISSN: 1432-2307
    Schlagwort(e): CD15 ; HBME-1 ; Thyroid ; Tumour ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We studied a wide range thyroid tumours and non-neoplastic conditions (total 463 cases) immunohistochemically to evaluate the possible diagnostic potential of HBME-1 and CD15 antibodies. HBME-1 monoclonal antibody recognizes a biochemically unknown epitope present in mesothelioma and variably present in some adenocarcinomas. CD15 antibodies recognize a sugar epitope also included in Lewis X blood group antigen. All papillary (145/145) and follicular carcinomas (27/27) were HBME-1 positive, usually in the the majority of tumour cells. In contrast, cases of nodular goitre and papillary hyperplasia either showed no reactivity or were focally positive (in a third of cases). The patterns of CD15 reactivity were generally similar, although smaller numbers of tumour cells were positive in papillary carcinomas, and only 50% of follicular carcinomas were positive. Because fetal thyroid also showed CD15 reactivity, this antigen appears to behave as an oncofetal antigen in relation to thyroid tissue. Anaplastic carcinomas were negative with both antibodies, indicating the loss of these epitopes upon high grade malignant transformation. We conclude that HBME-1 and CD15 immunohistochemistry may be helpful in the histological differential diagnosis between benign lesions and differentiated thyroid carcinomas, especially papillary tumours. Although the biochemical basis of HBME-1 reactivity is unknown, increased CD15 reactivity in malignant thyroid tumours probably reflects changes in thyroid follicular epithelial glycoconjugates related to malignant transformation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 21
    ISSN: 1432-2307
    Schlagwort(e): Hepatoblastoma ; Adhesion molecules ; CALLA ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Hepatoblastoma is an embryonal tumour of the liver, which often contains tissue components with multidirectional differentiation. The occurrence of cell surface antigens in this tumour has not been studied systematically, and we therefore investigated 20 hepatoblastomas for the expression of common acute lymphoblastic leukaemia antigen (CALLA) and cell adhesion molecules (CAMs) in their different tissue components. Epithelial tumour cells of fetal differentiation contained E-cadherin. This protein did not occur in tumour areas with embryonal or mesenchymal differentiation. In contrast, immature embryonal and anaplastic cells expressed CALLA and the hyaluronate receptor (HCAM, CD44). Both fetal and embryonal areas stained irregularly positive for ICAM-1, which, in contrast, was not present on anaplastic cells. Immature fibrous tissue did not contain any of these molecules except for ICAM-1. However, some cells adjacent to, or enclosed in, osteoid were positive for HCAM and NCAM. Like small undifferentiated hepatoblastoma cells, primitive mesenchymal spindle-shaped cells also expressed CALLA, HCAM, and the polysialylated embryonic form of NCAM strongly. This last is not present on other epithelial or mesenchymal tumour cells. Hepatoblastoma cells of varying differentiation express distinct patterns of CAMs and CALLA. Our results give further insight into their histogenesis and cellular interactions and may explain their variable ability for invasive growth and formation of metastases.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 22
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 429 (1996), S. 293-299 
    ISSN: 1432-2307
    Schlagwort(e): Intracellular amyloid ; Pituitary ; Adrenal gland ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The pituitary and adrenal glands are a functional endocrine unit affected by local or organ-limited senile amyloid syndromes. These occur as interstitial (pituitary only) or intracellular (pituitary and adrenal) varieties. The pituitary and right adrenal glands of each of 108 consecutive autopsy cases of individuals aged 85 years and over were investigated for the prevalence, distribution and immunostaining characteristics of local amyloid. Intracellular amyloid was detected in 77 (71%) pituitaries and 73 (68%) adrenals. Interstitial amyloid was found in 86 pituitaries (80%). Immunohistochemical studies, investigating different amyloid fibril proteins, amyloid P component, ubiquitin, intermediate filaments and pituitary hormones, failed to demonstrate any similarities, and a common origin is unlikely. Statistical analyses demonstrated significant correlations between the occurrences of all three local amyloids. The clinical and histopathological significance of local pituitary and adrenal amyloid remains obscure. The results suggested that the pathogenesis of the local senile amyloidoses of the pituitary and adrenals may be influenced by a common, still uncharacterized variable. It is not clear whether this variable also contributes to the pathogenesis of other senile amyloid syndromes, such as those associated with Alzheimers' disease.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 23
    ISSN: 1432-2307
    Schlagwort(e): Colorectal cancer ; Hereditary nonpolyposis colorectal cancer ; Carbohydrate antigens ; Lectin histochemistry ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The simple mucin-type carbohydrate antigens Tn, sialosyl-Tn, T and the ‘cryptic’ sialylated variant of the last represent the mucin core oligosaccharide structures that are produced in the initial steps of the mucin biosynthetic pathway. Utilizing monoclonal antibodies anti-Tn antigen (HB-Tn1), anti-sialosyl-Tn antigen (HB-STn1), anti-T antigen (HB-T1) and the biotinylated Amaranthus caudatus agglutinin (ACA), we have investigated the expression of the simple mucin-type carbohydrate antigens in hereditary nonpolyposis colorectal cancer (HNPCC; 15 cases) compared with sporadic colorectal cancer (CRC; 60 cases) and normal colonic mucosa (30 cases). A variable positivity of Tn, sialosyl-Tn, T and the cryptic sialylated form of this latter antigen was encountered in both HNPCC and sporadic CRC cases; in addition, in normal colonic mucosa a constant reactivity was encountered only for Tn and the cryptic sialylated form of T, while negative results were always obtained for sialosyl-Tn and T antigens. Statistical analysis, performed using a Chi-square test, showed significantly lower (P=0.037) expression of sialosyl-Tn and higher (P=0.022) expression of T in HNPCC than in sporadic CRC, suggesting a greater presence of β1,3 galactosyl-transferase activity in HNPCC than in sporadic CRC. We were unable to identify a peculiar phenotype for HNPCC with simultaneous evaluation of reactivity for HB-Tn1, HB-STn1, HB-T1 and ACA; the biological significance of the preferential expression of T antigen in HNPCC remains to be investigated.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 24
    ISSN: 1432-2307
    Schlagwort(e): Epidermal growth factor ; Epidermal growth factor receptor ; Immunohistochemistry ; Acute renal failure ; Proximal tubules
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Urinary immunoreactive epidermal growth factor (EGF) levels decrease, and renal immunoreactive EGF levels increase in rats with ischaemic acute renal failure (ARF). We investigated the immunohistochemical localization of EGF and EGF receptor in rabbits with ischaemic ARF to clarify the significance of renal EGF. Male New Zealand White rabbits underwent right nephrectomy prior to a 60 min renal artery clamp. At 3, 6, 24, 48, 72 and 96 h after ischaemia, serum urea nitrogen and serum creatinine were determined. Guinea pig anti-rabbit EGF antibody and monoclonal anti-EGF receptor antibody were used for the primary incubation. EGF was immunolocalized to the ascending limb of Henle and the distal convoluted tubule in the normal right kidneys. However, in the post ischaemic left kidneys at 6, 24, 48 and 72 h, immunoreactivity of EGF was associated with proximal tubules. In the normal kidneys, antibody to EGF receptor reacted with distal tubules and collecting ducts. In the ischaemic kidneys, EGF receptor was localized in the basolateral membrane in the proximal tubules. The expression of EGF and EGF receptor in renal tubules may play an important role in repair following ischaemic renal damage.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 25
    ISSN: 1432-2307
    Schlagwort(e): p53 ; Endometrioid carcinoma ; Endometrial hyperplasia ; Temperature-gradient gel electrophoresis ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The aim of this study was to evaluate the presence and distribution of p53 alterations in pure endometrioid adenocarcinomas (n=120) of different grades and stages, as opposed to normal endometrium (n=13) and various risk groups of hyperplasia (n=39). All samples were initially analysed by immunohistochemistry with the monoclonal antibody Ab-6. Normal endometria were negative. With increasing degrees of malignancy, the number of cases with p53 accumulation rose and ranged from 9% to 18% in hyperplasia, through 25% in lowgrade carcinomas (G1), to 69% in high-grade carcinomas (G3). This increase was also seen when comparing tumours by stage. Of carcinomas in stage IA, only 17% showed p53 immunostaining, in contrast with 72% in stage IC. Of this material, 34 carcinomas and 8 hyperplasias were analysed for p53 mutations in exons 5–8 by means of polymerase chain reaction and temperature-gradient gel electrophoresis (TGGE). In none of 5 hyperplasia and 6 of 12 carcinomas showing p53 accumulation by immunohistochemistry, p53 mutations were detected by TGGE. In contrast, 4 of 22 carcinomas harboured mutant p53 but were negative by immunohistochemistry. Immunohistochemical and molecular investigations revealed that p53 alterations are related to the standard prognostic markers of endometrial cancer, i.e. grading and staging. TGGE, an indirect screening procedure for p53 mutations, is used to detect the type of p53 alteration and may provide additional insight into the complex figure of p53 abnormalities in the development and progression of malignant endometrial lesions.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 26
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 428 (1996), S. 195-200 
    ISSN: 1432-2307
    Schlagwort(e): Papillary adenoma of type II pneumocytes ; Immunohistochemistry ; Electron microscopy ; Morphometry ; Multivariate cluster analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Papillary adenoma of type II pneumocytes is a rare tumour. It is considered to be a benign neoplasm and is derived from immature cells in the bronchioloalveolar epithelium, however, its biological nature has not been elucidated. We report a case of an adenomatous tumour; a papillary adenoma of type II pneumocytes, which we regard as possessing malignant potential. Light microscopically, as well circumscribed, papillary tumour of predominantly cuboidal cells resembling type II pneumocytes was found, but Clara type and ciliated cells were also present. Immunohistochemically, the tumour cells reacted positively with antibodies to surfactant apoproteins (A, B), carcinoembryonic antigen, cytochrome P-450 1A1-2 and 2B1-2. Ultrastructurally, many osmiophilic lamellar bodies and electron-dense granules were demonstrated. Semi-serial sections revealed signs of transbronchial dissemination and vascular invasion. Morphometry using 12-dimensional cluster analysis disclosed features of the tumour cells which resembled those of pneumocyte type II adenocarcinoma. These findings suggest that the present case has some malignant characteristics and originates from immature bronchiolar or alveolar cells, with a potential to develop into both type II pneumocyte and Clara cell type adenocarcinomas.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 27
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 428 (1996), S. 275-280 
    ISSN: 1432-2307
    Schlagwort(e): Varicella-zoster virus ; Herpes zoster ; Immunohistochemistry ; Hair follicle ; Sebaceous gland
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Herpes zoster is caused by reactivation of varicella-zoster virus (VZV) persisting in dorsal root or trigeminal ganglia. To clarify the pathway of viral spread from the ganglia to skin, 16 biopsy specimens of early skin lesions of herpes zoster obtained from the face and trunk of 13 patients were studied histologically and immunohistochemically using monoclonal antibodies to the structural proteins of VZV. VZV-infected cells were detected in the hair follicles in 10 of the 16 specimens and in the epidermis in 2 specimens. Infected cells were localized in the isthmus of every involved follicle (12/12), frequently in the stem (8/10) and infundibulum (6/10), and never in the bulb. The high frequency of follicular involvement in herpes zoster suggests that VZV spreads to the area of skin innervated by myelinated nerves, which end around the isthmus of hair follicles and sebaceous glands.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 28
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 428 (1996), S. 325-331 
    ISSN: 1432-2307
    Schlagwort(e): Arginase ; Gastric cancer ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract High levels of arginase have been detected in gastric adenocarcinoma. To examine the hypothesis that this is due to macrophage infiltration into the tumour, we localized the cellular distribution of arginase by immunohistochemical staining. We examined gastric adenocarcinomas and their corresponding normal tissues (n=45), leiomyomas (n=2), leiomyosarcomas (n=3), human gastric adenocarcinoma cell lines (n=3), and benign gastric ulcers (n=4) by the avidin-biotin-peroxidase complex technique. Macrophages with strong arginase immunoreactivity were observed infiltrating both gastric normal and cancer tissues. No arginase immunoreactivity was observed in normal mucosal gland, muscular and serosal tissues or benign gastric ulcers. The immunoreactivity of arginase was positive but heterogeneous in most specimens of gastric adenocarcinoma (62.2%) and was absent from gastric intestinal metaplasia, leiomyomas and leiomyosarcomas. Among the 28 neoplasms with arginase immunoreactivity, scattered immunoreactivity was also noted in adjacent dysplastic glands in 12 (42.8%) specimens. Arginase immunoreactivity was observed in all three gastric cancer cell lines. Arginase is present in the cytoplasm but not in the nucleus. These data suggest that the high arginase levels in adenocarcinoma cancer tissues originate largely from cancer cells.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 29
    ISSN: 1434-0879
    Schlagwort(e): Bcl-2 ; Immunohistochemistry ; Prostate cancer ; Prostatic intraepithelial neoplasia ; Prognosis ; Castration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The Bcl-2 protein prolongs cell survival by overriding apoptosis. To explore the role of Bcl-2 in prostate tumorigenesis, immunoreactivity for Bcl-2 was examined in untreated and androgen-deprived tumours and lymph node metastasis. Following the transurethral resection, 150 untreated patients were maintained under surveillance until death or for a minimum of 11 years, and castration was performed at symptomatic progression. The Bcl-2 index (BI) was defined as the percentage of immunoreactive cells in a tumour. The mean BI was 12 in the untreated tumours, and BI was significantly higher in high-grade tumours, mean BI 17, than in low-grade tumours, mean BI 6. There was no correlation between BI and stage or metastatic disease, nor did BI predict cancer-specific survival. In 16 androgen-deprived, but non-relapsed tumours, the mean BI was 54, at a mean time of 22 months after castration, indicating a permanent increase of Bcl-2 protein expression after androgen withdrawal. In six patients, tissues from the prostate tumour and obturator lymph node metastasis were available. Four primary tumours immunostained for Bcl-2, but only one metastasis stained. Foci of high-grade prostatic intraepithelial neoplasia (PIN) were present in 44 of the 150 untreated tumours. All PIN foci were intensely immunoreactive for Bcl-2, and mean BI was 79, suggesting that Bcl-2 protein expression is associated with early prostate tumorigenesis.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 30
    ISSN: 1432-0533
    Schlagwort(e): Key words Amyloid β-protein ; Alzheimer’s disease ; Monoclonal antibodies ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We have used the end-specific monoclonal antibodies to amyloid β-protein (Aβ), BC05 and BA27, to investigate the molecular characteristics of the cored or stellate type of amyloid plaque that is sometimes present, along with the more common diffuse type of plaque, in the cerebellar cortex in (usually younger) cases of Alzheimer’s disease. In five such cases of Alzheimer’s disease the (many) cored plaques were strongly BA27, but less strongly BC05, immunopositive, indicating the presence of (much) Aβ40 and Aβ42(43), respectively. Diffuse plaques were only BC05 positive, except on rare occasions where a little BA27 reactivity was present. Cerebellar cored plaques, like the diffuse plaques, were not associated with tau or astrocytic (glial fibrillary acid protein) immunoreactivity, though in contrast to cerebellar diffuse plaques, but like the cored plaques in the cerebral cortex, microglial cells were usually present. The cause of this form of Aβ deposition in the cerebellum is not known. Although congophilic angiopathy was severe in two patients, this was only mild in the others. Similar plaques were also seen in the cerebellum of most, but not all, of five other younger patients with chromosome 14-linked Alzheimer’s disease and again, although congophilic angiopathy was severe in one such case with many cored plaques, this was not so in the others. At present the relationship (if any) between this pathological change and the possession of the chromosome 14 mutation of Alzheimer’s disease or the occurrence of congophilic angiopathy remains uncertain.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 31
    ISSN: 1432-0533
    Schlagwort(e): Key words Nucleolin ; Meningiomas ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Nucleolin (110 kDa) is a major nucleolar protein in eukaryotic cells and one of the nucleolar organizer region (NOR)-associated proteins. We studied immunohistochemically 32 cases of meningioma, using specific antisera against nucleolin, and analyzed various nucleolin parameters, such as the number of regions and the total area of nucleolin staining per nucleus. The mean number and area of nucleolin stainings per nucleus were compared with the histological malignancy and Ki-67/MIB-1 proliferation index; the correlation with parameters of silver-stained NOR (AgNOR) was also studied. The results showed that there were statistically significant differences in the mean number and area of nucleolin stainings per nucleus between meningiomas and other two groups, atypical and anaplastic meningiomas (P 〈 0.05), although there was no difference between atypical and anaplastic meningiomas. The mean number and area of nucleolin stainings per nucleus were correlated with the incidence of Ki-67 positivity and AgNOR area. In view of the technical problems inherent in AgNOR staining, immunohistochemistry for nucleolin may represent a more specific and reproducible means for NOR visualization and be a promising technique for assessing cell proliferation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 32
    ISSN: 1432-0533
    Schlagwort(e): Key words Myasthenia gravis ; Utrophin ; Dystrophin ; Motor end-plate ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We studied the densities of utrophin and dystrophin at the motor end-plates of patients with myasthenia gravis (MG) using immunohistochemical analysis. The densities were compared with those found in patients with amyotrophic lateral sclerosis, Lambert-Eaton myasthenic syndrome and normal controls. Utrophin was reduced at the motor end-plates of MG patients, in association with a reduction of α-bungarotoxin binding sites. In contrast, the density of dystrophin at the motor end-plate of MG patients was not significantly different from that found in the controls. We conclude that, at the motor end-plate, utrophin may be more closely associated than dystrophin with the acetylcholine receptor, and that it plays a different role.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 33
    ISSN: 1432-0533
    Schlagwort(e): Key words Growth-associated protein 43 ; Immunohistochemistry ; Rat ; Spinal cord ; Trauma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Growth-associated protein 43 (GAP43) is one compound used to indicate growth of axonal endings during development and regeneration, particularly of peripheral neurons. Using immunohistochemistry, we have studied the expression of GAP43 in the spinal cord of rats subjected to mild, moderate or severe compression injury and used neurofilament immunostaining to demonstrate axonal injuries. Samples removed from the compressed T8–9, the cranial T7 and the caudal T10 segments were studied at 4 h, 24 h, 4 days and 9 days after injury. Control rats showed a moderate immunostaining of neurons in dorsal root ganglia, weak staining of ventral motor neurons and, with the exception of the corticospinal tracts, a weak staining in some axons of the longitudinal tracts of the cord. Injury in the compressed region led to increased GAP43 immunoreactivity in axons of normal and expanded size. This occurred particularly 1–4 days after injury and normalized 9 days thereafter. More marked immunostaining was present in the cranial and caudal segments. The corticospinal tracts never showed such staining. The increase of GAP43 immunostaining is presumably caused by disturbed axonal transport from neurons with the capacity to synthesize and transport the GAP43 antigen. Transported material may thus be available for regeneration of axons, but this source of material may vary between different classes of axons within the cord.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 34
    ISSN: 1432-0533
    Schlagwort(e): Key words Creutzfeldt-Jakob disease ; Prion protein ; Codon 232 ; Immunohistochemistry ; Experimental ; transmission
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We describe the clinical, neuropathological, immunohistochemical and transmission findings in three patients with Creutzfeldt-Jakob disease (CJD) with a substitution from methionine to arginine at codon 232 (M232R) in the prion protein (PrP) gene. The patients with M232R presented clinically with rapidly progressive dementia, myoclonus, and periodic synchronous discharges in the electroencephalogram. These findings were mostly consistent with those for sporadic CJD. All patients reached the stage of akinetic mutism between 2 and 6 months, and died between 4 and 24 months after the onset of the disease. Histopathological examination revealed spongiform changes, neuronal loss and severe astrocytosis. Immunohistochemical staining for PrP showed diffuse gray matter staining, including synaptic structures. However, no plaque-type PrP deposition was observed in the affected brain tissue sections. The brain homogenates from two patients were successfully transmitted to experimental animals. Since the same mutation was not found in 100 healthy control individuals, the mutation might be associated with the disease. The clinicopathological and experimental transmission studies of CJD patients with this PrP gene mutation may thus help us to determine both phenotypic variations and the potential infectivities in different forms of prion diseases.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 35
    ISSN: 1432-0533
    Schlagwort(e): Key words PMP-22 ; CMT1A ; Onion bulb formation ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Peripheral myelin protein 22 (PMP-22) is a glycoprotein expressed in the myelin sheath of myelinated Schwann cells. Duplication of the PMP-22 gene and its gene dosage effect have been postulated to be involved in the pathogenesis in the majority of individuals with Charcot-Marie-Tooth disease type 1A (CMT1A). Northern blot analysis has demonstrated that the mean relative ratio of PMP-22 mRNA/β-actin mRNA in biopsied nerves of patients with CMT1A is significantly higher than that in disease controls. To investigate whether the elevated expression of PMP-22 mRNA is reflected in the amount and the localization of PMP-22, we analyzed PMP-22, myelin basic protein (MBP), protein zero (P0), and S-100 immunoreactivities in biopsied nerves from six patients with CMT1A, five patients with other types of CMT, five patients with acquired demyelinating neuropathies, and two normal subjects. In all patients with CMT other than CMT1A and acquired demyelinating neuropathy, as well as in normal subjects, the myelin sheath was immunoreactive for PMP-22, MBP, and P0, while the Schwann cell cytoplasm was immunoreactive only for S-100. In five out of six patients with CMT1A, however, the PMP-22 immunoreactivity was present not only on the myelin sheath but also in the Schwann cell cytoplasm and onion bulbs (OBs). Although OBs are nonspecific and also seen in other inherited or acquired demyelinating neuropathies, the PMP-22-positive OBs were seen exclusively in CMT1A.The finding suggested that the expression of PMP-22 was abnormal for its localization and probably for the amount in patients with CMT1A carrying duplication of the PMP-22 gene.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 36
    ISSN: 1432-0533
    Schlagwort(e): Key words Malignant rhabdoid tumor ; Immunohistochemistry ; Central nervous system
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Malignant rhabdoid tumors (MRT) are characterized by a typical light microscopic morphology with uniformly round tumor cells, vacuolated cytoplasm with occasional round, hyaline intracytoplasmic, periodic acid-Schiff-positive inclusions, vesicular nuclei with prominent nucleoli and positive immunoreactivity for vimentin. The histogenesis of MRT is controversial. Five cases of primary central nervous system (CNS) rhabdoid tumors in children are presented. Immunohistochemical, light and electron microscopic features are compared with primary CNS malignant rhabdoid tumors reported in the literature. Expression of various neurofilaments in our cases of primary CNS rhabdoid tumors was prominent and we therefore favor a neural differentiation of extrarenal intracerebral rhabdoid tumors.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 37
    ISSN: 1432-0533
    Schlagwort(e): Key words Amyotrophic lateral sclerosis ; Golgi ; apparatus ; Intraneuronal inclusions ; Bunina body ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We applied immunohistochemical techniques to study alterations of the Golgi apparatus, and to determine possible relationships between this complex and the intraneuronal inclusions of lower motor neurons of patients with the sporadic form of amyotrophic lateral sclerosis (ALS). Spinal cords from normal individuals served as controls. Monoclonal antibodies to the Golgi zone and to Golgi β-COP protein were used. Immunoreactivity with these antibodies was seen in frozen sections of paraformaldehyde-fixed spinal cord tissue, but not in formalin-fixed, paraffin-embedded specimens. The immunoreaction products were seen as granular structures, diffusely distributed in neurons and glial cells. Although immunostaining of some ALS neurons was reduced, fragmentation of the Golgi apparatus was not evident with either antibody. Bunina bodies and skein-like inclusions, characteristically found in spinal anterior horn cells of ALS patients, were not stained by these antibodies to epitopes of the Golgi apparatus, nor were Lewy body-like hyaline inclusions, present in some cases of sporadic ALS and reported to be characteristic of familial ALS with posterior column degeneration. These results suggest that components of the Golgi apparatus are not directly incorporated into intraneuronal inclusions. However, the possibility that abnormal proteinaceous material of the Golgi apparatus may be involved in their genesis cannot be ruled out.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 38
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 194 (1996), S. 49-55 
    ISSN: 1432-0568
    Schlagwort(e): Pacemaker ; Interstitial cells of Cajal ; Intestine ; Ultrastructure ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Interstitial cells associated with the submuscular plexus of the guinea pig colon were studied by electron microscopy and by light microscopic wholemount stretch preparations. Their cytoplasmic features are similar to those of fibroblasts and they contain a well-developed Golgi apparatus, granular endoplasmic reticulum and many mitochondria. Intermediate filaments are abundantly distributed throughout the perinuclear region and processes. Numerous caveolae, a basal lamina and subsurface cisterns are observed on the cell membrane as in smooth muscle cells. The most characteristic feature of this cell type is the existence of many large gap junctions that interconnect these cells to each other and with the smooth muscle cells. Nerve varicosities containing synaptic vesicles are observed in close apposition with cells of this type. Whole-mount preparations stained by the zinc iodide-osmic acid method and by vimentin immunohistochemistry clearly demonstrated the stellate form of these gap junction-rich cells and suggested that they correspond to the interstitial cells of Cajal.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 39
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 91 (1996), S. 376-384 
    ISSN: 1432-0533
    Schlagwort(e): Key words Epilepsy ; Immunohistochemistry ; Neurotransmitter ; Pathology ; Tumor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Circumscribed cortical lesions are frequently encountered in patients with chronic focal epilepsies. However, the pathogenesis of seizures is poorly understood. To determine whether the perilesional cortex shows evidence for abnormal excitatory or inhibitory neurochemical activity, we immunohistochemically examined the distribution of the α1 subunit of the GABAA receptor (GABAR), the N-methyl-d-aspartate receptor subunit 1 (NR1), and glutamate decarboxylase (GAD) in 30 surgical specimens of neocortical epilepsy-associated lesions. These comprised 7 low-grade gliomas, 2 gangliogliomas, 2 dysembryoplastic neuroepithelial tumors, 4 glioneuronal malformations, 5 vascular malformations, and 10 glial or gliomesodermal scars. All specimens originated from patients with chronic pharmacoresistant epilepsy. In 73% of the cases there was a distinct difference in immunoreactivity for GABAR, GAD or NR1 between the perilesional zone and the normal cortex. With each of the markers there was reduced perilesional immunoreactivity in 30% of the specimens. Increased staining for GAD was seen in 17%, for GABAR in 7%, and for NR1 in 13% of the cases. The age at surgery, onset of seizures, epilepsy duration, and maximal seizure frequency did not differ significantly between patients with normal and those with altered perilesional immunoreactivity patterns. Although the perilesional changes for GAD, GABAR or NR1 were heterogeneous, they suggest a disturbed balance between excitatory and inhibitory synaptic transmission which may contribute to the pathogenesis of focal seizures.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 40
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 91 (1996), S. 409-415 
    ISSN: 1432-0533
    Schlagwort(e): Key words Nerve growth factor ; Low-affinity nerve ; growth factor receptor ; Phosphoprotein B-50/ ; neuromodulin ; Immunohistochemistry ; Human ; skeletal muscle
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Phosphoprotein B-50, also termed neuromodulin or growth-associated protein GAP43, is a membrane-bound molecule expressed in neurons. It is particularly abundant during periods of axonal outgrowth in development and regeneration of the central and peripheral nervous systems. Recently it was reported that B-50 plays a role in the growth morphology of regenerating muscle fibers. Moreover, in vitro studies have demonstrated that the expression of B-50 in the pheochromocytoma PC12 cells can be stimulated by the nerve growth factor (NGF). Expression of the low-affinity nerve growth factor receptor (LNGFR) during muscle regeneration has also been reported. Here, we studied the expression of NGF, LNGFR and B-50 in myopathy. To investigate the state of regeneration, we examined serial sections stained to demonstrate neural cell adhesion molecule and desmin. Light microscopy showed that muscle fiber regeneration in idiopathic inflammatory myopathy corresponds closely to NGF, LNGFR and B-50 immunoreactivity. The coexpression of phosphoprotein B-50, NGF and LNGFR in regenerating muscle fiber corroborates the assumption that in muscle there is a trophic pathway concerning phosphorylation or de novo synthesis of B-50 by the NGF via the LNGFR. In conclusion, a simultaneous expression of NGF, LNGFR and B-50 in muscles plays a role in the growth morphology of regenerating muscle fibers.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 41
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 91 (1996), S. 155-160 
    ISSN: 1432-0533
    Schlagwort(e): Key words Ubiquitin ; Immunohistochemistry ; Rat ; Spinal cord ; Trauma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The ubiquitin-mediated proteolytic pathway is an important mode of protein degradation in various tissues. Since breakdown of proteins may occur in axons after injury we evaluated the presence of ubiquitin-like immunoreactive material in rat spinal cord following compression injury of mild, moderate and severe degrees at T8–9 level, resulting in no neurological deficit, reversible paraparesis and paraplegia of the hind limbs, respectively. Rats with mild to severe compression injury surviving 1–4 days showed numerous, intensely immunoreactive expanded axons at the site of compression. The labelled axons were randomly distributed in the longitudinal tracts but they were never found in the corticospinal tracts. No labelling was detected by 9 days after injury. In addition, the presence of labelled axons was investigated in the T7 and the T10 segments from rats with moderate compression. No labelling was seen in T7, but in T10 segments many immunoreactive axons were present. Control rats did not show immunoreactive axons in the spinal cord. Neurons of dorsal root ganglia, trigeminal ganglia and of the grey matter of the spinal cord were immunoreactive. Cerebral cortical neurons did not show ubiquitin expression. Thus, compression of the rat spinal cord causes a transient accumulation of ubiquitin-like immunoreactive material in axonal swellings. Even though the dynamics of ubiquitin conjugates are not fully understood, the observed axonal accumulation presumably reflects arrested anterograde axonal transport of protein chiefly derived from neurons of dorsal root ganglia and the local neurons of the spinal cord. The presence of ubiquitin in damaged axons is one prerequisite for degradation of abnormal proteins by the ubiquitin-mediated proteolytic pathway, which may be activated in reactive axonal swellings.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 42
    ISSN: 1432-0533
    Schlagwort(e): Key words Cytoplasmic body myopathy ; Spheroid ; body myopathy ; Desmin myopathy ; Electron ; microscopy ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Clinicopathological, immunohistochemical and biochemical studies were performed on seven patients from five families showing an abnormal accumulation of desmin in the muscle fibers. Late onset myopathy was observed in all the cases studied. The clinical features were heterogeneous and usually nonspecific. However, some patients presented with dysphonia, dysphagia or cardiomyopathy. These features are highly suggestive of desmin myopathy. Using electron microscopy, desmin myopathy is characterized by an accumulation of granulofilamentous material. Depending on the distribution of the material, however, three different patterns of desmin accumulation can be observed: (1) large circumscribed inclusions, (2) intermyofibrillar areas of diffusely distributed material, and (3) deposits around large spheroid bodies. The second pattern is characterized by a rubbed-out appearance using oxidative enzyme reactions. For all the patients studied here, the immunohistochemical data showed that the desmin accumulation fitted these three patterns of distribution. For six patients, immunoblot analysis confirmed the desmin accumulation patterns and showed that an increase in the expression of the 53-kDa protein had occurred. The third pattern of desmin accumulation confirms the pathological heterogeneity of cytoplasmic and spheroid bodies. Desmin does not accumulate in all cytoplasmic and spheroid body myopathies, as observed in two other familial cases presented here.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 43
    ISSN: 1432-0533
    Schlagwort(e): Key words Primary progressive aphasia ; Immunohistochemistry ; Ubiquitin ; Spongy degeneration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We report the histopathological and immunohistochemical findings in a patient with primary progressive aphasia and abnormally ubiquitinated neurites in the cerebral cortex. Neuropathological examination showed severe neuronal loss and astrocytosis with a spongy change in the frontal cortex and neostriatum. Immunohistochemistry for ubiquitin antibody showed many immunoreactive dystrophic neurites in the superficial layer of the affected cortices and putamen. Those neurites were neither argentophilic nor stained with other antibodies against neurofilament, tau, or microtubule-associated protein-2. There were no neuropathological changes characteristic of Alzheimer’s disease, Pick’s disease, or Creutzfeldt-Jakob disease. Immunoelectron microscopy using anti-ubiquitin antibody showed inclusions in the dendrites, consisting mainly of granular and filamentous material. These pathological features, unusual in primary progressive aphasia, indicate the neuropathological heterogeneity of this disease condition.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 44
    ISSN: 1432-0568
    Schlagwort(e): Aromatase ; Estrogen receptor ; Immunohistochemistry ; Brain ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We elucidated the anatomical relationship between estrogen receptors and aromatase, the enzyme converting androgens to estrogens, in the fetal and neonatal rat brain by means of double immunohistochemical labeling, using antibodies against rat estrogen receptors and human placental aromatase cytochrome P450. Numerous aromatase-immunoreactive neurons were found in the medial preoptic area, the bed nucleus of the stria terminalis, the medial amygdaloid nucleus and the ventromedial nucleus. Estrogen receptors were also abundant in these areas. Most of the aromatase-immunoreactive neurons showed immunoreactivity for estrogen receptors in the medial subdivision of the bed nucleus of the stria terminalis and in the posterodorsal division of the medial amygdaloid nucleus. There were also many double-labeled cells in the ventromedial nucleus. However, in the medial preoptic area the localization of aromatase-immunoreactive neurons was distinct from that of neurons containing estrogen receptors. These results suggested that estrogens, which are converted from androgens in aromatase-containing neurons, are involved in the sexual differentiation of the brain through estrogen receptors within aromatase-immunoreactive neurons in the bed nucleus of the stria terminalis, the medial amygdaloid nucleus and the ventromedial nucleus, but through estrogen receptors in aromatase-immunonegative neurons in the medial preoptic area.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 45
    ISSN: 1432-0568
    Schlagwort(e): 2′,5′-Oligoadenylate synthetase ; Immunohistochemistry ; Mouse ; Reproductive organs ; Oocyte
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Although 2′,5′-oligoadenylate synthetase (25AS) is an enzyme induced by inferferon (IFN) or viral infections and mediates one of the principal antiviral pathways turned on by IFN, low constitutive levels of the enzyme can be detected in various “normal” animals that have not been treated with IFN or virus. The distribution of this enzyme in the female and male reproductive organs of normal healthy mice was studied by Western blotting and by an immunohistochemical method, using a specific monoclonal antibody. On Western blotting, an antibody to 42-kD 2-5AS reacted with extracts from the ovary, oviduct, uterus, vagina, and placenta among the female reproductive organs, and testis, epididymis, and ductus deferens in the male. Immunohistochemically, the 2-5AS was localized on the following cells in the female reproductive organs: oocytes in the ovary; epithelium in the oviduct, uterus, and vagina; and trophoblasts in the placenta. Furthermore, the 2-5AS was localized on the epithelium and muscular layer in the ductus deferens and epithelium in the penis of the male mice, whereas the epithelium of the testis, epididymis, and seminal vesicle were stained faintly. It is well known that IFN is produced continuously in normal mice, so the 2-5AS in the tissues of normal mice is considered to be induced by such IFN produced under physiological conditions. Expression of the 2-5AS on the epithelium and trophoblasts in the reproductive organs may be responsible for the prevention of viral infections. However, the enzyme in oocytes may have some functions other than as an antiviral agent, since the enzyme was not detectable in embryos during early development.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 46
    ISSN: 1432-0568
    Schlagwort(e): Vascular system ; Smooth muscle cell ; Immunohistochemistry ; α-smooth muscle actin ; Mouse embryo
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The initial phase of smooth muscle differentiation in the vascular system of the mouse embryo was observed immunohistochemically with monoclonal antibody against α-smooth muscle actin. Few smooth muscle cells were detected in the vascular system of the 9.5-day embryo, where only the dorsal aorta and umbilical artery showed signs of smooth muscle differentiation. In the 10.5-day embryo, smooth muscle cells were observed in the dorsal aorta, ventral aorta, omphalomesenteric artery and vein, umbilical artery and vein, internal carotid artery, aortic arches III and IV, and subclavian artery. The extent of smooth muscle differentiation varied among these vessels and among regions of a vessel. At 11.5 days of gestation, smooth muscle cells appeared in the basilar artery, vertebral artery, aortic arches VI, intersomitic artery, ductus venosus, and caudal artery. Smooth muscle cells were absent from the venous system characteristic of the embryo at the stages examined. Alpha-smooth muscle actin-positive cells were also observed in allantoic mesoderm in the placenta at 9.5 days, when the umbilical vessels were not surrounded by smooth muscle cells. Vascular smooth muscle cells appear to arise independently from mesenchyme at multiple sites in the vascular system.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 47
    ISSN: 1432-0533
    Schlagwort(e): Key words In situ polymerase chain reaction ; Immunohistochemistry ; Human T cell lymphotropic ; virus type I ; Proviral DNA ; Polymyositis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We have analyzed muscle biopsy specimens from polymyositis patients who are also positive for human T cell lymphotropic virus type I (HTLV-I) using both immunohistochemistry for surface antigens of lymphocytes and macrophages and in situ polymerase chain reaction for HTLV-I proviral DNA on the same sections. We found HTLV-I in CD4+ cells but not in macrophages. This finding suggests that most of the HTLV-I-containing CD4+ cells are not macrophages but lymphocytes.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 48
    ISSN: 1432-0533
    Schlagwort(e): Key words Acute encephalopathy ; Cerebral infarction ; Hemolytic uremic syndrome ; Immunohistochemistry ; Verocytotoxin-producing Escherichia coli
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract To study the pathogenesis of the central nervous system (CNS) involvement associated with verocytotoxin-producing Escherichia coli infection, we developed an animal model by administering verocytotoxin 2 to rabbits either intravenously or intrathecally. After an interval of 2–9 days, the rabbits became paralyzed in a dose-dependent manner and in the absence of renal impairment. The minimal intravenous and intrathecal doses that produced these neurological signs were 250 and 0.4 ng/kg, respectively. After intravenous administration, most of the toxin was cleared from the serum within 24 h, with concomitant transition of a small amount into the cerebrospinal fluid. Pathological examination revealed that neurons in various CNS regions showed atrophy, cytoplasmic hyperchromasia and nuclear pyknosis as early as 6 h after administration. The distribution of affected neurons was constant and irrespective of the route of administration. Abnormalities of the blood vessels, such as the thickening of arterioles walls, were noted from 2 days after administration. The vascular lesions became more prominent after the intrathecal injection, which caused thrombosis and multiple infarction. Selective deposition of the toxin on the vessel walls was demonstrated immunohistochemically. Thus, the pathological manifestations of verocytotoxin 2 neurotoxicity consisted essentially of two types of lesions, early neuronal and late vascular, both of which might have developed under the influence of the toxin that had entered the CNS by crossing or circumventing the blood-brain barrier.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 49
    ISSN: 1432-0568
    Schlagwort(e): Thyroid cartilage ; Immunohistochemistry ; Vascularization ; Cartilage canals ; Collagens
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract In this study the collagenous composition of cartilage canals in human thyroid cartilage, which are perichondral invaginations of blood vessels and connective tissue, and the surrounding cartilage matrix were investigated by immunolabelling with specific antibodies against type I, II, pro-III, IV and X collagen. During childhood and early adolescence no cartilage canals were detected in thyroid cartilage, and immunolabelling for type IV collagen was restricted to basal lamina components of blood vessels in the perichondrium. First immunolabelling for type IV collagen, belonging to blood vessels in cartilage canals, in both sexes was detected about the end of the second decade; it was localized in the dorsal part of the thyroid cartilage plate. At this time thyroid cartilage has already reached its final form and size. As revealed by von Kossa staining, vascularization preceded mineralization and ossification. In contrast to the male thyroid cartilage plate, no immunostaining for type IV collagen and no ossification was detected in the ventral half of female thyroid cartilage even in advanced age. The extracellular matrix of cells in cartilage canals showed positive immunostaining for collagen types I and pro-III as well as for collagen type II, indicating that the cells in the canal possess fibroblastic and chondrogenic properties. The extracellular matrix of hypertrophic chondrocytes adjacent to cartilage canals showed strong immunoreactivity for type X collagen. First mineralization was detected close to cartilage canals, suggesting that mineralization in human thyroid cartilage starts in the extracellular matrix adjacent to cartilage canals.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 50
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 195 (1996), S. 65-70 
    ISSN: 1432-0568
    Schlagwort(e): Key words α-Amino-3-hydroxy-5-methyl-4-isoxazole proprionic acid receptor ; Glutamate receptor development ; Immunohistochemistry ; Synaptogenesis ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We studied the immunohistochemial localization of the glutamate receptors (GluR-1, -2, and -3,) in the developing rat cerebral cortex and hippocampus using antibodies to GluR1 and to an epitope common to GluR2 and GluR3 (GluR2/3) subunits. In the cerebral cortex, GluR1 immunoreactivity appeared in the neurons from postnatal day (PND) 0, increased with maturation, was highest at PND 10, decreased until PND 30, and thereafter remained at the same level as on PND 0. GluR2/3 immunoreactivity appeared earlier in scattered neurons on embryonal day (ED) 18, increased with maturation and reached a peak between PND 10 and PND 15, after which the immunoreactivity gradually decreased and reached a plateau at PND 30. For both GluR1 and GluR2/3, some of the pyramidal neurons showed intense staining. In the pyramidal layers of the hippocampus, GluR1 and GluR2/3 immunoreactivity was found in all the pyramidal neurons of the CA1–4 area from ED 20. In the dentate gyrus of the hippocampus, GluR1 and GluR2/3 immunoreactivity was found in the neurons of the granule cells after PND 0. Immunoreactivity in the neurons of the subiculum was found after PND 5 and that of the polymorphic cell layers was found after PND 15–20. Our results indicate that the development of glutamate receptor subunits in the rat cerebral cortex and hippocampus is expressed in different spatial patterns and distinct temporal patterns throughout development and is scheduled during the early postnatal period, when synaptic plasticity or synaptic connection occurs in these regions.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 51
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 194 (1996), S. 373-378 
    ISSN: 1432-0568
    Schlagwort(e): Paravertebral sympathetic ganglia ; Calretinin ; Aging ; Immunoblotting ; Immunohistochemistry ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Calretinin is an “EF-hand” calcium-binding protein involved in the maintenance of intracellular calcium ion homeostasis. This study was understaken to investigate the presence of calretinin in human lumbar paravertebral sympathetic ganglia from subjects of different ages (26–85 years) using immunohistochemical and immunoblotting methods. Calretinin-like immunoreactivity was found in a subpopulation of postganglionic sympathetic neurons, whose percentage decreased progressively with aging by about 50% (63% of immunoreactive neurons at ≤40 years; 29% at ≥81 years) whereas the neuronal density remained basically unchanged. Calretinin-like immunoreactivity showed a granular pattern of cytoplasmic distribution suggesting preferential localization of this protein associated with intracellular membranes. Occasionally diffuse cytosolic labelling was also observed. The immunoblotting demonstrated a protein band with an estimated molecular weight of 30 kDa, approximately. Present results provide, for the first time, evidence for the presence of calretinin in human paravertebral sympathetic ganglia. Since the number of calretinin-like immunoreactive neurons decreased significantly with aging our findings suggest an involvement of this protein in the age-dependent impairment of sympathetic function.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 52
    ISSN: 1432-0568
    Schlagwort(e): Temporomandibular joint ; Immunohistochemistry ; Proteoglycan ; Aging ; Development
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract There is little information available regarding the morphological and biomolecular characteristics of mandibular condylar cartilage. The purpose of this study was to determine the age-related changes in the morphology and immunolocalization of glycosaminoglycans (GAGs) in mandibular condyles. The mandibular condylar cartilages from 4-, 8-, 16-, 32-, and 64-week-old Wistar male rats were examined to verify the localization of chondroitin-4-sulfate (Ch-4S), chondroitin-6-sulfate (Ch-6S) and keratan sulfate (KS) using an indirect immunofluorescent technique with three monoclonal antibodies for glycosaminoglycans, 2-B-6, 3-B-3 and 5-D-4, respectively. Morphologically, the condylar cartilage was a growth cartilage during growing periods, began to differentiate into articular cartilage from the central area of 16-week-old condyles, and became mature articular cartilage at 32 weeks of age. A regional difference was found in the morphological features and distribution of GAGs between the anterior, central, postero-superior and posterior areas of the condyles at each age. The immunohistochemical localizations of these three glycosaminoglycans showed age-related, morphology-dependent changes, from growth cartilage to articular cartilage-like cartilage. Immunoreactions for all of the antibodies decreased progressively with age in the interterritorial matrix, while the pericellular and territorial matrix in the condylar cartilage of the mandible maintained relatively higher immunoreactivity. In conclusion, age-related and regional differences in the localization of glycosaminoglycans Ch-4S, Ch-6S, and KS were found in the mandibular condyles in rats, and these changes are believed to be related to functional and developmental requirements.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 53
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 91 (1996), S. 511-518 
    ISSN: 1432-0533
    Schlagwort(e): Key words Congenital malformations ; Developmental cataract ; Hydrocephalus ; Immunohistochemistry ; Optic nerve coloboma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Ophthalmic pathological findings of hydrolethalus, a midline malformation syndrome, were determined in three fetuses aborted between the 14th and 19th gestational week. The eyes were serially sectioned and analyzed using light microscopy and a panel of 13 antibodies to neuronal, glial, epithelial, and mesenchymal elements of the eye. The general morphological and antigenic development of the anterior segment, retina and choroid were normal, but some lens fibers were vacuolated and irregular in all eyes. A coloboma of the optic nerve was constant and corresponded in its severity to the systemic manifestations. It ranged from segmental dysplasia of the optic nerve head to a colobomatous orbital cyst with secondary microphthalmos and deranged development of the eye. Glial tissue extended through a defect in the sheaths of the optic nerve in three eyes, communicating with retinoblastic tissue in the orbit. Evidence of secondary optic nerve hypoplasia was present in all eyes, and a separate chorioretinal coloboma was present in one eye. Ocular anomalies should be considered one hallmark of hydrolethalus syndrome, and they may help to differentiate it from other overlapping malformation syndromes. In particular, colobomatous dysplasia and hypoplasia of the optic nerve seem to be typical of hydrolethalus syndrome. Histopathological studies of the eyes may help the neuropathologist in making the differential diagnosis of midline malformation syndromes.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 54
    ISSN: 1432-0533
    Schlagwort(e): Key words Central neurocytoma ; Glial fibrillary acidic protein ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We have identified two central neurocytomas which contained cells co-expressing glial fibrillary acidic protein and synaptophysin defined by double-label immunostaining. Dual-positive cells were mostly polygonal in shape and with a morphological appearence similar to that of reactive astrocytes. This distinct morphology could be used to distinguish cells expressing glial fibrillary acidic protein from cells with round and clear cytoplasm which did not express glial fibrillary acidic protein and which composed the majority of the tumor. Samples containing polygonal cells were selected for electron microscopy from toluidine blue-stained semithin sections. Ultrastructural findings were similar in both neurocytomas, with both being composed predominantly of round cells with clear cytoplasm corresponding to the clear cells identified by light microscopy. Dense-core vesicles and clear vesicles were frequently observed in the cell processes. Apart from these clear cells, polygonal cells with electron-dense cytoplasm were noted. Paralleling the results of double immunostaining, these polygonal cells contained both dense-core vesicles and intermediate, presumably glial filaments. Microtubules and lipofuscin granules were also observed. These results suggest that cells expressing glial fibrillary acidic protein in central neurocytoma include tumor cells with both neuronal and glial characteristics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 55
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 92 (1996), S. 35-41 
    ISSN: 1432-0533
    Schlagwort(e): Key words Acquired immunodeficiency syndrome ; Blood-brain barrier ; Cerebral vessels ; Immunohistochemistry ; Lectin histochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract In human immunodeficiency virus 1 (HIV-1)-infected patients, a hypoperfusion is seen by SPECT analyses in different brain regions but a specific pattern for the predominance of a specific brain region has not been found. The vessels of the cerebral cortex of the frontal, temporal, parietal, and occipital lobes of acquired immunodeficiency syndrome (AIDS) brains and control brains were analyzed by immunohistochemistry and lectin histochemistry. Immunohistochemistry was performed for collagen IV, laminin (basal lamina), and factor VIII (endothelial cell) and lectin histochemistry [Ricinus communis agglutinin (RCA-I), Ulex europaeus agglutinin (UEA-I), wheatgerm agglutinin (WGA) and soybean agglutinin (SBA)] was used to study changes of glycoproteins in the endothelial cell membrane. Vessels were counted in the gray and white matter, and their staining intensity for the different antibodies and lectins was rated using a three-point scale. Immunoreactivity for collagen IV was reduced in AIDS brains, which may be related to thinning of the basal lamina of cerebral vessels, as has previously been shown by electron microscopy. Lectin histochemistry with SBA, UEA-I and WGA indicated loss of glycoproteins in the membrane of endothelial cells. The data from the present study show morphological changes of the endothelial cells and of the basal lamina in the brain of individuals with AIDS, and might represent the morphological sequelae of a disturbed blood-brain barrier, or may account for the hypoperfusion seen in SPECT analyses.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 56
    ISSN: 1432-0533
    Schlagwort(e): Key words Cytoplasmic dynein ; Influenza A virus ; A/Aichi/2/68 ; Molecular mimicry ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Immunohistochemistry with an antibody to influenza A/Aichi/2/68 (H3N2) virus was performed using normal mouse, rat and human brain tissues. Dot-like or filamentous structures in the neuronal cytoplasm were clearly stained. Axons were also stained, but weakly. Lewy bodies in Parkinson’s disease substantia nigra were also positive. Immunoscreening of the antibody using mouse brain cDNA revealed that this antibody recognized the heavy chain of cytoplasmic dynein. Immunoblot analysis also showed that the reactive molecule was the same size as cytoplasmic dynein (microtubule-associated protein 1C). This is an example of molecular mimicry between cytoplasmic dynein and influenza A virus, and the antibody appears to be useful for the localization on cytoplasmic dynein in the central nervous system.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 57
    ISSN: 1432-0533
    Schlagwort(e): Key words Presenilin ; Alzheimer’s disease ; Immunohistochemistry ; Golgi apparatus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The immunolocalization of presenilin in human brain was studied using two antibodies raised against different portions of presenilin 1 (S182) protein. A granular staining was found in the cytoplasm of neurons in cortical layers III and V. One of the antibodies, also reactive to presenilin 2 (E5-1) protein, additionally stained dendrites and axons. This was seen in normal brains as well as in brains affected by Alzheimer’s disease. Less prominent immunolabeling was noted in some senile plaques. No relationship to neurofibrillary tangles was found in double-labeling experiments combined with anti-paired helical filament-tau antibody (AT8). The widespread expression of presenilin in normal brain suggests a physiological role of the protein.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 58
    ISSN: 1432-0533
    Schlagwort(e): Key words Lytico-bodig ; Guam ; Alzheimer’s disease ; Complement system ; β-Amyloid protein ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Extracellular neurofibrillary tangles (eNFTs) are the insoluble cytoskeletal debris left behind when neurons with intracellular neurofibrillary tangles (iNFTs) die. Reactive microglia and reactive astrocytes gather around eNFTs. Many inflammatory proteins are deposited in their vicinity, including activated components of the classical complement pathway. Agents which are potential activators of the pathway include β-amyloid protein (Aβ) and amyloid P (AP), since these in vitro activators have been reported to be associated with both senile plaques (SPs) and eNFTs. To investigate the apparent order in which these proteins are deposited, we studied by immunohistochemistry the relative association of AP, Aβ, and the classical complement protein C4d with eNFTs in Alzheimer’s disease (AD), parkinsonism-dementia complex of Guam (lytico-bodig, LB), and elderly non-demented cases. In normal elderly cases with mild tangle development, most but not all eNFTs were AP positive. Substantially fewer eNFTs were C4d positive, and in two of the three cases no eNFTs were Aβ positive. In AD and mild LB cases with more extensive tangle development, a high portion of eNFTs were AP positive, and most of them were C4d positive. Only a few were Aβ positive. In severe LB cases, with dense tangle development, almost all eNFTs were AP and C4d positive, and a significant number were also Aβ positive. AP seems to be deposited early in eNFT exposure and could therefore be a potential activator of the complement pathway, while Aβ deposition occurs relatively late in the process, and is therefore unlikely to be responsible.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 59
    ISSN: 1432-0568
    Schlagwort(e): Serotonin ; Immunohistochemistry ; Central nervous system ; Pigeon
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The distribution of serotonin (5-HT)-containing perikarya, fibers and terminals in the brain of the pigeon (Columba livia) was investigated, using immunohistochemical and immunofluorescence methods combined with retrograde axonal transport. Twenty-one different groups of 5-HT immunoreactive (IR) cells were identified, 2 of which were localized at the hypothalamic level (periventricular organ, infundibular recess) and 19 at the tegmental-mesencephalic and rhombencephalic levels. Ten of the cell groups were situated within the region of the midline from the isthmic to the posterior rhombencephalic level and constituted the raphe system (nucleus annularis, decussatio brachium conjunctivum, area ventralis, external border of the nucleus interpeduncularis, zona peri-nervus oculomotorius, zona perifasciculus longitudinalis medialis, zona inter-flm, nucleus linearis caudalis, nucleus raphe superior pars ventralis, nucleus raphe inferior). The 9 other cell populations belonged to the lateral group and extended from the posterior mesencephalic tegmentum to the caudal rhombencephalon [formatio reticularis mesencephali, nucleus ventrolateralis tegmenti, ectopic area (Ec) of the nucleus isthmo-opticus (NIO), nucleus subceruleus, nucleus ceruleus, nucleus reticularis pontis caudalis, nucleus vestibularis medialis, nucleus reticularis parvocellularis and nucleus reticularis magnocellularis]. Combining the retrograde axonal transport of rhodamine β-isothiocyanate (RITC) after intraocular injection and immunohistofluorescence (fluoresceine isothiocyanate: FITC/5-HT) showed the centrifugal neurons (NIO, ec) to be immunonegative. Serotonin-IR fibers and terminals were found to be very broadly distributed within the brain and were particularly prominent in several structures of the telencephalon (archistriatum pars dorsalis, nucleus taeniae, area parahippocampalis, septum), diencephalon (nuclei preopticus medianus, magnocellularis, nucleus geniculatus lateralis pars ventralis, nucleus triangularis, nucleus pretectalis), mesencephalon-rhombencephalon (superficial layers of the optic tectum, nucleus ectomamillaris, nucleus isthmo-opticus and in most of the cranial nerve nuclei). Comparing the present results with those of previous studies in birds suggests some major serotonin containing pathways in the avian brain and clarifies the possible origin of the serotonin innervation of some parts of the brain. Moreover, comparing our results in birds with those obtained in other vertebrate species shows that the organization of the serotoninergic system in many regions of the avian brain is much like that found in reptiles and mammals.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 60
    ISSN: 1432-0568
    Schlagwort(e): Avian gut ; Differentiation ; Gut endocrine cells ; Regulatory peptides ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Chromogranin A-(CgA-) and chromogranin B-(CgB-)-immunoreactive endocrine cells were investigated in the chicken intestine during embryonic and post-hatching life. CgA- and CgB-immunoreactive cells first appeared in the intestinal tract at various embryonic ages from day 10 in the cloaca to day 16 in the distal ileum and colon. To identify the CgA- and CgB-immunoreactive cells, each tissue section was double-immunostained using a panel of polyclonal antibodies raised against gut amine/peptides. Almost all the serotonin-immunoreactive cells co-localised CgA and CgB along the entire intestinal mucosa and at all ages examined. In contrast, substance P-, peptide tyrosine tyrosine-, neurotensin- and secretin-immunoreactive cells displayed heterogeneous co-localisation patterns. For example, either all or only some cells of a given endocrine type co-stored Cg; they did so variously-only in the embryo, only after hatching, or at both stages, and co-localizing cells were sometimes located within the mucosa only in the villi and not in the glands, and sometimes vice versa. All the CgA/CgB-immunoreactive cells also displayed argyrophilia.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 61
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 194 (1996), S. 253-257 
    ISSN: 1432-0568
    Schlagwort(e): Epidermal growth factor receptor ; Dorsal root ganglia ; Immunoblotting ; Immunohistochemistry ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Transforming growth factor-α (TGFα) enhances neuronal survival and neurite outgrowth in cultured dorsal root ganglia (DRG) sensory neurons. It binds a membrane protein, denominated epidermal growth factor receptor (EGFr). EGFr has been localized in developing and adult human DRG. However, it remains to be elucidated whether all DRG neurons express EGFr or whether differences exist among neuronal subtypes. This study was undertaken to investigate these topics in adult human DRG using immunoblotting, and combined immunohistochemistry and image analysis techniques. A mouse monoclonal antibody (clone F4) mapping within the intracytoplasmic domain of EGFr was used. Immunoblotting revealed two main proteins with estimated molecular masses of ∼- 65 kDa and 170 kDa, and thus consistent with the full-length EGFr. Additional protein bands were also encountered. Light immunohistochemistry revealed specific immunoreactivity (IR) for EGFr-like proteins in most (86%) primary sensory neurons, the intensity of immunostaining being stronger in the small- and intermediate-sized ones. Furthermore, EGFr-like IR was also observed in the satellite glial cells of the ganglia as well as in the intraganglionic and dorsal root Schwann cells. Taken together, our findings demonstrate that EGFr, and other related proteins containing the epitope labeled with the antibody F4, are responsible for the EGFr IR reported in DRG. Furthermore, we demonstrated heterogeneity in the expression of EGFr-like IR in adult human primary sensory neurons, which suggests different responsiveness to their ligands.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 62
    ISSN: 1432-0568
    Schlagwort(e): Ontogeny ; Circumvallate papilla ; Taste buds ; Innervation ; Protein gene-product 9.5 ; Neuron-specific enolase ; Calcitonin gene-related peptide ; Immunohistochemistry ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The present study was made to investigate the ontogeny of protein gene-product 9.5 (PGP 9.5)-like immunoreactivity (-LI) in the developing mouse circumvallate papilla (CVP), and its distribution was compared to that of neuron-specific enolase (NSE) and calcitonin gene-related peptide (CGRP). In adult CVP, PGP 9.5-LI was observed in the subgemmal nerve plexus; some thin PGP 9.5-like immunoreactive (-IR) nerve fibers penetrated taste buds and apical epithelium. PGP 9.5-LI was also observed in the spindle-shaped cells in taste buds, and a small number of round- or oval-shaped ganglionic cells in the lamina propria. The distribution of NSE-LI was comparable to that of PGP 9.5-LI. CGRP-LI was observed in the nerve fibers only; distribution of CGRP-IR nerve fibers was similar to that of PGP 9.5-IR nerve fibers, although the number of CGRP-IR nerve fibers was smaller than that of PGP 9.5-IR nerve fibers. At least six developmental stages were defined with regard to the developmental changes in the distribution of PGP 9.5-LI from embryonic day (E) 12 to adulthood: Stage I (E12–13) — a dense nerve plexus of PGP 9.5-IR nerve fibers was detected in the lamina propria beneath the core of newly-formed papilla. Stage II (E14–16) — thin PGP 9.5-IR nerve fibers penetrated the apical epithelium, and a few round-shaped cells in the apical epithelium also displayed PGP 9.5-LI. Stage III (E17–18) — thin PGP 9.5-IR nerve fibers penetrated the inner lateral epithelium of the trench. Stage IV [Postnatal day (P) 0–3] many PGP 9.5-IR nerve fibers penetrated the outer lateral epithelium of the trench; later in this stage, taste buds appeared. Stage V (P5–10) — a small number of PGP 9.5 IR cells in the taste buds appeared, and their number increased gradually. Stage VI (PI4-adult) — the number of PGP 9.5-IR taste cells increased and reached the adult level, while the number of PGP 9.5-IR nerve fibers decreased. The development of NSE-LI was similar to that of PGP 9.5-LI. CGRP-IR nerve fibers were detected at E12 in the lamina propria, and the development of the intraepithelial CGRP-IR nerve fibers was similar to that of PGP 9.5-IR nerve fibers. The present results indicate that invasion by nerve fibers of the epithelium of lingual papillae occurs in a complex manner, and that these nerve fibers may participate in the formation of the taste buds.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 63
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 195 (1996), S. 31-39 
    ISSN: 1432-0568
    Schlagwort(e): Key words Chondrocyte ; Skeletal muscle ; Calcium-binding protein ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We have investigated the expression and the localization of annexin V and annexin VI during the development of rat fetal limb buds by immunoblot and immunocytochemical analysis. Neither annexin V nor annexin VI was detectable in undifferentiated mesenchymal cells in limb buds of the day-13–day-16 rat fetus. Skeletal muscles, whose progenitor cells migrate from the somites and appeared in the limb buds at day 14, dramatically expressed annexin VI on the cell surface after differentiation from mononucleated myogenic cells into multinucleated myotubes. At day 16 both annexin V and annexin VI were found to be expressed in differentiated chondrocytes as well as in the perichondrium, a precursor of chondrocytes, whereas the compact layer of mesenchymal cells surrounding a chondrification center (precartilage) did not show any immunoreactivity for either of these proteins. The results suggest a close relationship between the expression of these annexins and cell differentiation of chondrocytes and skeletal muscles during limb but development.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 64
    ISSN: 1432-0568
    Schlagwort(e): Articular cartilage ; Development ; Type I collagen ; In situ hybridization ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The present study was designed to investigate whether or not chondrocytes in articular cartilage express type I collagen in vivo under physiological conditions. Expressions of the gene and the phenotype of type I collagen were examined in rat tibial articular cartilage in the knee joint during development. Knee joints of Wistar rats at 1, 5, and 11 weeks postnatal were fixed in 4% paraformaldehyde with or without 0.5% glutaraldehyde and decalcified in 10% EDTA. After the specimens were embedded in paraffin and serial sections made, adjacent sections were processed for immunohistochemistry and in situ hybridization for type I collagen. The epiphysis of the tibia was composed of cartilage in week-1 rats. Formation of articular cartilage was in progress in week 5 as endochondral ossification proceeded and was completed in week 11. Anti-type I collagen antibody stained only the superficial area of the epiphysis in week 1, but the immunoreactivity was expanded into the deeper region of the articular cartilage with development in weeks 5 and 11. Hybridization signals for pro-alpha 1 (I) collagen were seen in some of chondrocytes in the epiphysis of the week-1 tibia. The most intense signals were identified in chondrocytes in week 5 and the signals appeared weaker in week 11. The present study demonstrated that chondrocytes synthesize type I collagen and accumulate the protein in the matrix during development of the articular cartilage.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 65
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 1213-1223 
    ISSN: 0392-6737
    Schlagwort(e): Optoelectronic devices ; Other solid inorganic materials ; Electron states in low-dimensional structures (superlattices, quantum well-structures and multilayers) ; Quantum optics ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary The properties and preliminar applications of porous-silicon (p-Si) microcavities are here reported. These structures are based on a planar resonator formed by two narrow-band high-reflectance distributed Bragg reflectors separated by a thin active optical layer, all of which are made of p-Si layers. The accurate control of the electrochemical dissolution of Si lets us realize p-Si multilayers with the desired refractive indices sequence. Large improvements of the emission properties of p-Si microcavities with respect to standard p-Si samples are observed: 1) increased emission intensity, 2) spectral narrowing of the emission band, and 3) high directionality in the emission pattern. Resonant-cavity light-emitting diodes with higher efficiencies and stabilities with respect to standard p-Si/metal devices are demonstrated. Reflectivity changes due to absorption saturation have been observed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 1121-1129 
    ISSN: 0392-6737
    Schlagwort(e): Optoelectronic devices ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary We present a theoretical study of two infinite wires of Si with a different lateral size. The analysis is based on the linear muffin tin orbitals method in the atomic sphere approximation (LMTO-ASA). We consider free, partially and totally H-covered [001] Si quantum wires with rectangular cross-section. The results of this investigation prove the quantum wire nature of porous Si and interpret many of its physical features. In particular we show thata) as expected quantum confinement originates the opening of the LDA gap;b) the gap opening effect is asymmetric: 1/3 of the widening is in the valence band, while 2/3 in the conduction band;c) the near band gap states originate from Si atoms located at the center of the wire;d) the confinement is enhanced in the case of free surfaces;e) the imaginary part of the dielectric function shows a low-energy side structure strongly anisotropic, identified as responsible of the luminescence transition;f) the presence of dangling bonds destroys the luminescence properties;g) in spite of featurec), all Si atoms are collectively involved in the luminescence transition;h) the shift detected by the Si L2, 3VV Auger signal is due to H-interaction effect and is not a measure of the quantum confinement effect;i) the Si atoms probed by the Si L2, 3VV Auger are bonded with H and H2.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 67
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 1131-1148 
    ISSN: 0392-6737
    Schlagwort(e): Optoelectronic devices ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary In this work we demonstrate that efficient light emission at 1.54 μm can be achieved when Er ions are incorporated into crystalline Si or in heavily oxygen-doped amorphous and polycrystalline Si films (SIPOS). We have found that temperature quenching of photo- and electroluminescence, which is the major limitation towards the achievement of room temperature luminescence, can be strongly reduced by codoping these films with oxygen. This impurity is already present in as-prepared SIPOS and it is introduced by ion-implantation in crystalline Si. Er luminescence is obtained under both optical and electrical excitation and we demonstrate that excitation occurs through a carrier-mediated process. Electrical excitation is obtained by incorporating Er in properly designed device structures. It is found that this excitation can occur both through the recombination of hole-electron pairs and through impact excitation of the Er ions by hot electrons. These two mechanisms have different efficiencies and impact excitation is shown to prevail at room temperature. These data are presented and possible future developments are discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 68
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 1111-1119 
    ISSN: 0392-6737
    Schlagwort(e): Optoelectronic devices ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary The striking optical properties of porous silicon (PS) show a twofold aspect typical of an ordered and a disordered material, respectively. Raman, electron microscopy, and resonant photoluminescence studies indicate that the light emission originates from crystalline regions. On the contrary, several features, like the non-exponential decay of photoluminescence (PL), the broad emission spectrum, the photoluminescence fatigue under light exposure etc. are typical of a disordered material and reminiscent of similar effects founde.g. in amorphous semiconductors. These twoapparently conflicting aspects have for a long time hindered the understanding of the basic light emission mechanism. In this paper we report new optical data showing that disorder in porous silicon leads to strong carrier localisation. Light emission in PS is suggested to occur through transitions involving localized states.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 69
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 1159-1165 
    ISSN: 0392-6737
    Schlagwort(e): Optoelectronic devices ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary Porous silicon is an attractive material for silicon optoelectronics. The great advantage of porous silicon lies on the simple way of production which makes silicon nanostructures easily available. After several papers have been published on this topic, we are able to identify some disadvantages connected to the porous nature of the material and to the method of fabrication. Other dry processes can be used to produce Si nanostructures. In this paper we present a method fully compatible with the standard semiconductor technology. The optical and structural properties of the nanocrystalline films so far obtained are presented, together with some promising results indicating good electrical properties.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 70
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 1167-1177 
    ISSN: 0392-6737
    Schlagwort(e): Optoelectronic devices ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary We report room temperature time-resolved photoluminescence (PL) and temperature dependence of continuous wave (cw) PL studies of high fluence (from 3·1016 to 3·1017 cm−2) Si+-implanted thermal SiO2 layers after annealing at high temperature (T=1000°C). Such measurements were related to TEM analysis of samples. Nancocrystals were observed at TEM only a samples implanted at higher fluence. In these samples a near infrared PL signal peaked at approximately 1.5 eV with decay time of about 100 μs is present. Besides, in all samples a light emission is present in the green region of the spectrum. The intensity of the emission shows large variations with ion fluence, and is characterized by 0.4, 2 and 7 ns decay times.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 71
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 337-340 
    ISSN: 0392-6737
    Schlagwort(e): Atoms and molecules ; Magnetic ordered materials: other intrinsic properties ; Magnetomechanical and magnetoelectric effects, magnetostriction ; Mössbauer effect: other γ-ray spectroscopy ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary The high-energy heavy-ion irradiation of magnetic materials induces not only amorphous matter in the ion tracks but also improvement or even creation of new magnetic properties in a stressed shell surrounding the track core. Two examples are presented in this paper: magnetization creation in the spinel ZnFe2O4 after Kr, Xe and Pb irradiations and trapping of magnetic domains in another spinel, the magnetite Fe3O4, after lead irradiation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 72
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 359-363 
    ISSN: 0392-6737
    Schlagwort(e): X- and γ-rays instruments and techniques ; γ-rays ; Mössbauer effect ; other γ-ray spectroscopy ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary In the present work we report an investigation on cultures of the human osteosarcoma cell line «MG-63» and the human osteoblastic cell line «HOBIT». We have examined the combined effects of hematin and 14.4keV gamma-radiation from a Mössbauer source. Preliminary results seem to confirm the trend already observed for the bone marrow system. Different degrees of growth inhibition were observed when hematin alone and hematin plus gamma-rays were administered to the cultures. It was previously found that hematin has no toxic effects on normal cells up to a concentration of 10−4 M, but the same concentration produces various degrees of inhibition on cultures of tumor cells. While no significant effect could be attributed to irradiation alone, hematin plus irradiations show a larger inhibition than that expected for pure additive effects.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 73
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 381-384 
    ISSN: 0392-6737
    Schlagwort(e): Mössbauer effect ; other γ-ray spectroscopy ; Phonons and vibrations in crystal lattices ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary The phonon energy spectra of a polycrystalline α-Fe foil were observed at 150 K and 300 K by using the nuclear resonant scattering of synchrotron radiation. In each spectrum, inelastic scattering was observed at both sides of the elastic peak. It was found that the ratio of the elastic-scattering component and the asymmetry of the intensity of the side bands observed at 150 K are larger than those observed at 300 K, respectively. The observed temperature-dependent spectra are in good agreement with the spectra calculated from the phonon energy distribution function. One of the advantageous features of this method is that the excitation of only a specific element is possible. Our results show that this method is applicable to the study of lattice dynamics and opens a new field of the nuclear resonant scattering spectroscopy.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 74
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 163-180 
    ISSN: 0392-6737
    Schlagwort(e): Fine particle systems ; PACS 76.80 ; Mössbauer effect ; other γ-ray spectroscopy ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary Mössbauer spectroscopy is well known to be a very sensitive technique for studying small magnetic particles: small variations in the dynamic properties often manifest themselves as rather large changes in the spectra. However, anay detailed investigation is limited by the complexity of the phenomena and also by the line shape problem. As a result, variations in Mössbauer features between samples can always be interpreted in several ways. Utilization of other techniques to support the conclusions in indispensable. This will be emphasized in the case of γ-Fe2O3 nanoparticles, the dynamic properties of which have been studied over a very wide time range using measurements of the zero-field-cooled magnetization, thermoremanent magnetization, and a.c. susceptibility at various frequencies, in addition to Mössbauer spectroscopy. After a survey of the basic laws of superparamagnetic relaxation and the effects of interparticle interactions, this paper will show how the approximations usually made for interpreting Mössbauer data can lead to misinterpretation of the phenomena.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 75
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 221-225 
    ISSN: 0392-6737
    Schlagwort(e): Radiolysis, dissociation and ionization by X-ray, γ-ray and particle radiation ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary The final product of the gamma-radiolysis of tetralithium iron (III) trioxalate chloride nonahydrate has been identified by Mössbauer spectroscopy as FeC2O4·2H2O. The radiolytic decomposition proceeds as a first-order process due to the original compound depletion and to the radiolytic stability of the ferrous compound. Chemical calibration of the relative peaks areas of the two iron species indicates that the correspondingf-factors ratio is unaffected by the radiolysis.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 76
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 243-246 
    ISSN: 0392-6737
    Schlagwort(e): Mösbauer effect ; other γ-ray spectroscopy ; Fe and its alloys ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary We report on low-temperature (4.2 K)57Fe Mössbauer studies of the ternary alloy system Fe(Sb1−x Te x )2 for 0.5≤x≤1.0. The Mössbauer spectra are electric-quadrupole doublets for all the specimens, indicating a non-magnetic character. The quadrupole splitting decreases with the increase in tellurium concentration. FeTe2 has also been studied in external magnetic fields up to 6T. These experiments show that the electric-field gradient in this alloy is negative and has an asymmetry parameter of η ≈0.7.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 77
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 227-230 
    ISSN: 0392-6737
    Schlagwort(e): Mössbauer spectra ; Mössbauer effect ; other γ-ray spectroscopy ; Crystalline state (including molecular motions in solids) ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary C60 (Buckminsterfullerene) is isolated from organic solvents above 260 K as an f.c.c. solid with complete orientational disorder. The rotational dynamics are diffuse and isotropic, with a short (12 ps) correlation time at 300 K. Below 260 K, the solid forms in a simple cubic lattice withPa3 symmetry. The librational motion occurs by activated jumps with a correlation time of about 60 ns at 200 K. To gain further insight into the dynamics of C60, the compound C60Fe(CO)4 (I) (generously made available to us by A. Stephens and M. Green of Oxford University) has been studied by57Fe Mössbauer spectroscopy. As expected, the resonance at 90 K consists of a doublet with an isomer shift (relative to metallic iron) of 0.034(1) mm s−1 and a quadrupole splitting of 1.607(5) mm s−1. There is no significant temperature-dependent, intensity asymmetry of the doublet. The temperature dependence of the effect magnitude is well fit by a linear regression over the range 85〈T〈210 K. To elucidate the relationship of these results to the effect of the C60 moiety in I, further lattice dynamical Mössbauer studies have been carried out on (maleic anhydride) Fe(CO)4 (II), one of the few isolatable tetracarbonyl complexes of iron. For (II), the quadrupole splitting is 1.371(5) mm s−1 at 90 K, and the temperature, dependence of the isomer shift is smaller than it is for (I), while the temperature dependence of the recoil-free fraction is significantly larger in (I) than in (II).
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 78
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 237-241 
    ISSN: 0392-6737
    Schlagwort(e): Mössbauer effect ; other γ-ray spectroscopy ; Electrochemical devices ; Crystal symmetry: models, space groups and crystalline systems and classes ; Electron microscopy and other methods ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary We present here a study carried out on In16Sn4S32 and In16Fe8S32 spinels. Electronic and local environment changes of Sn and Fe are discussed from recorded Mössbauer parameters. In the case of the tin thiospinel, a reduction process from SnIV to SnII is obvious till an amount of 8 inserted Li. For the iron thiospinel a migration of iron atoms from the octahedral to the tetrahedral sites is observed. In the region of higher lithium amounts (10– Li), in both spinels a further environment appears indicating an increase of covalency.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 79
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 1149-1157 
    ISSN: 0392-6737
    Schlagwort(e): Optoelectronic devices ; Other solid inorganic materials ; Time-resolved optical spectroscopies and other ultrafast optical measurements in condensed matter ; Interfaces ; heterostructures ; nanostructures ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary We report the observation of strong red- and blue-light emission in free-standing porous-silicon samples prepared fromn + substrates at different anodization current densities. The surface morphology of the free-standing samples has been analyzed by means of atomic-force microscopy. Upon excitation with nanosecond pulses at room temperature, both blue and red luminescence bands appear, peaked around 3.2 and 2.0 eV, respectively. An extensive study of the time-resolved behavior of the photoluminescence signal reveals different dynamical features for the two spectral regions. The observed long decay time (several μs) of the red band reflects the predominant effect of non-radiative processes and is consistent with models based on excition diffusion through the interconnected silicon nanocrystals (quantum dots) skeleton. The relatively fast blue-band decay time (≈400 ns) is shown to be related to non-radiative recombination through trap states at the silicon nanocrystal surface.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 80
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 1179-1186 
    ISSN: 0392-6737
    Schlagwort(e): Methods of deposition of films and coatings ; film growth and epitaxy ; Electrochemistry and electrophoresis ; Surface and interface chemistry ; Infrared and Raman spectra and scattering ; Photoluminescence ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary Porous-silicon layers were prepared by anodic oxidation of mono- and multi-crystalline Si substrates,n + andp-doped, in aqueous HF solutions containing surfactants. The resulting samples show a bright red-orange photoluminescence: PL spectra and uniformity are analysed as a function of surfactants kind and concentration. Moreover, the results of Raman spectroscopy are discussed in terms of current theories.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 81
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 1225-1232 
    ISSN: 0392-6737
    Schlagwort(e): Methods of deposition of films and coatings ; film growth and epitaxy ; Surface treatments ; Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity ; Photoelectric conversion: solar cells and arrays ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary Porous silicon was formed on multicrystalline Si substrates by stain etching in aqueous HF/HNO3 solutions. In this work optical and electrical properties of the resulting films are discussed as a function of process parameters. Porous-Si films have been shown to be able to reduce surface reflectance to 3% in 350–700 nm wavelength range and their application in anti-reflection coating of photovoltaic solar cells has been demonstrated, obtaining (10×10) cm2 multicrystalline Si solar cells with efficiency approaching 12% under standard AM 1.5 simulated sunlight.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 82
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 1233-1239 
    ISSN: 0392-6737
    Schlagwort(e): Optoelectronic devices ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary A first structural investigation, carried out by transmission electron microscopy on porous-silicon samples fromp +, 〈111〉-oriented substrates is presented. The samples, which show intense visible room temperature luminescence, are composed by an interconnected network of crystalline nanostructures. Evidences of the pores propagation along the 〈100〉 directions are provided. The optical and morphological characteristics of the investigated samples are found to be much similar to those of samples coming fromp-type, non-degenerate, 〈100〉-oriented substrates rather than those obtained from 〈100〉 substrates with comparable resistivity. This striking effect is explained by invoking different etch-limiting mechanisms during pore formation. Their relative weights are proposed to depend on the crystallographic orientation of the silicon specimen subjected to etching.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 83
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 263-268 
    ISSN: 0392-6737
    Schlagwort(e): Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source X-ray scattering, etc.) ; Critical-point effects, specific heats short-range order ; Antiferromagnetics ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary Mössbauer measurements have been made on two kinds of spin-glass (SG) systems: one is the magnetically non-diluted mixed compound Fe0.5Mn0.5TiO3 with the SG-freezing temperatureT SG=21.5K, and the other is the diluted one Fe0.2Mg0.8TiO3 withT SG=6K. We have shown that the temperature variation of the Mössbauer spectrum of Fe0.2Mg0.8TiO3 above and around itsT SG is essentially different from that of Fe0.5Mn0.5TiO3: the former is typical of a cluster-glass and the latter of an ordinary spin-glass. The present work has clearly demonstrated that the Mössbauer spectroscopy is the most useful and unique technique to distinguish a cluster-glass from an ordinary spin-glass.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 84
    ISSN: 0392-6737
    Schlagwort(e): Mössbauer effect ; other γ-ray spectroscopy ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary Sediment cores with different sub-bottom depths (I: 45 cm and II: 700 cm) from the Peru Basin have been investigated. From the depth profile of the relative amount of Fe(II) a redox zone is obtained which correlates with the organic carbon flux into the sediment (core I). Mössbauer parameters suggest that the iron in the sediments is mainly contained in clay minerals and to varying extent also in goethite.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 85
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 371-374 
    ISSN: 0392-6737
    Schlagwort(e): X-ray ; Mössbauer and other γ-ray spectroscopic analysis methods ; Molecular biophysics ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary The Rayleigh scattering of Mössbauer radiation has been measured on highly oriented fibres of Na-hyaluronate at different hydration levels. The elastic-and inelastic-scattering intensities, measured as a function of the scattering vectorQ, have provided information on the dynamic structuring of the water molecules to the polysaccharidic chains.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 86
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 385-388 
    ISSN: 0392-6737
    Schlagwort(e): Mössbauer effect ; other ψ-ray spectroscopy ; Strong field excitation of optical transitions in quantum systems multiphonon processes ; dynamic Stark shift ; Effects of internal magnetic fields ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary We have studied the time dependence of Mössbauer absorption in a magnetically soft sample of Fe18Ni82 permalloy under the influence of a radio-frequency (r.f.) magnetic field. Absorption was measured as a function of the r.f. field phase at specific gamma-ray energies. We have shown that measuring the time dependence of absorption makes it possible to differentiate between purely magnetic and magnetoacoustic modulation mechanisms even in cases where clear distinction is not visible in conventional energy domain spectra.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 87
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 145-161 
    ISSN: 0392-6737
    Schlagwort(e): Metal-insulator transitions ; High-pressure and shock-wave effects in solids ; Mössbauer effect ; other γ-ray spectroscopy ; Transition-metal compounds ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary Most previous studies of magnetism in various compounds under extreme conditions have been conducted over a wide pressure range at room temperature or over a wide range of cryogenic temperatures at pressures below 20 GPa (200 kbar). We present some of the most recent studies of magnetism over an extended range of temperatures and pressures far beyond 20 GPa,i.e. in regions of pressure-temperature (P-T) space where magnetism has been largely unexplored. Recent techniques have permitted investigations of magnetism in selected 3d transition metal compounds in regions ofP-T where physical properties may be drastically modified; related effects have often been seen in selected doping studies at ambient pressures. We present57Fe and129I Mössbauer isotope studies covering the range 300–4 K to sub-megabar pressures in compounds such as Sr2FeO4, LaFeO3 and FeI2, representative of a broad class of 3d transition metal compounds. At ambient pressure the electronic structure of the transition metal atom in these antiferromagnetic insulators extends from 3d 4 to 3d 6 and has a distinct influence on the pressure evolution of their magnetic properties. Mössbauer studies of these compounds are considered in conjunction with available structural and electrical transport data at pressure.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 88
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 299-304 
    ISSN: 0392-6737
    Schlagwort(e): Layer structures: multilayers, and superlattices (growth structure, and nonelectronic properties) ; Magnetism in interface structures (including layer and superlattice structures) ; Mössbauer effect ; other γ-ray spectroscopy ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary The synthesis of a new BCT Fe phase was performed in Fe/Ir(100) superlattices grown by MBE. Magnetic properties of57Fe/Ir(100) superlattices with 4 ml Fe and variable Ir thickness (2–30 Å) are investigated by57Fe conversion electron Mössbauer spectroscopy in the 4.2–300 K temperature range. Two spectral components are evidence, related, respectively, to Fe atoms involved in the central part of the iron layers and at the interface between iron and iridium layers. The appearance of a high magnetic hyperfine splitting in the iron BCT structure above a volume threshold of 12 Å3 is evidenced. Marked differences are observed between the mean magnetic properties and the local ones suggesting strong relaxation effects.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 89
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 259-262 
    ISSN: 0392-6737
    Schlagwort(e): Mössbauer effect, other γ-ray spectroscopy ; Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source X-ray scattering, etc.) ; X-ray Mössbuer and other γ-ray spectroscopic analysis methods ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary A thermodynamic calculation of the Fe−Cr−Ni phase diagram suggests that the composition 30 at.%Cr-5 at.%Ni is expected to be found inside the spinodal line, whereas 16 at.%Cr-5 at.%Ni is expected outside at 723 K. These two alloys have been thermally aged for time periods up to 40 minutes at 723K. A significant broadening of the magnetic-hyperfine-field distribution indicates that Fe-30 at.%Cr-5 at.%Ni undergoes typical spinodal decomposition in agreement with the calculation. Spinodal decomposition is distinguished from nucleation-growth by a detailed analysis of the magnetic-hyperfine-field distribution.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 90
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 137-144 
    ISSN: 0392-6737
    Schlagwort(e): Intrinsic properties of magnetically ordered materials ; Magnetic films and multilayers ; Nuclear magnetic resonance and relaxation ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary Man-made low-dimensional magnetic systems including surfaces, interfaces and multilayers, have attracted a great amount of attention in the past decade because, as expected, the lowered symmetry and coordination number offer a variety of opportunities for inducing new and exotic phenomena and so hold out the promise of new device applications. Local spin density functional (LSDF)ab initio electronic-structure calculations employing the full-potential-linearized augmented-plane-wave (FLAPW) method have played a key role in the development of this exciting field by not only providing a clearer understanding of the experimental observations but also predicting new systems with desired properties. One of the striking successes of theory in the last decade has been the calculation of hyperfine fields at surfaces and interfaces. Concurrently, several groups have followed the pioneering work of Korecki and Gradmann and have measured hyperfine fields at surfaces and interfaces. In this paper, we review new features of hyperfine-interaction investigations in man-made materials which emphasizes how the close interplay of theoretical determinations and experiment are essential because the hyperfine field is not proportional to the magnetization and so interpretations of experiment are totally dependent on theory.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 91
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 181-198 
    ISSN: 0392-6737
    Schlagwort(e): Impurities: concentration, distribution, and gradients ; Doping and impurity implantation in germanium and silicon ; Interaction between different crystal defects ; gettering effect ; Calculations of total electronic binding energy ; Elemental semiconductors ; Mössbauer effect ; other γ-ray spectroscopy ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary Experimental results are presented on the study of Sb-H complexes in crystalline silicon, employing119Sb→119Sn source Mössbauer spectroscopy and a low-energy H implantation technique. In addition to a visible component, we observe a large decrease of the Mössbauer intensity associated with the trapping of hydrogen, even at low temperatures. This is interpreted as the formation of a component with a negligible recoilless fraction. The different Mössbauer components were studied as a function of H dose, H-implantation temperature and annealing temperature. The data show that the visible component is associated with the well-known SbH complex, whereas the invisible component is associated with the formation of SbH n (n≥2) complexes. We show that these complexes are in thermal equilibrium with a larger hydrogen reservoir (H 2 * ), which governs their thermal stability. No Sb-H complexes are observed inp-type Si after H-implantation, in agreement with the current belief that hydrogen has a deep donor level in the gap. The microscopic structure of the various Sb-H and Sn-H complexes was studied with first-principles calculations using the pseudopotentialdensity-functional approach. The structure of the Sb-H complex is found to be similar to the P-H complex, with the H in an antibonding site of a Si atom neighbouring the Sb impurity. For SbH2 three configurations are found with energies differing by less than ≈ 0.1 eV. We find that the reaction SbH+H≠SbH2 is exothermic. We argue that the SbH2 complexes are shallow donors, irrespective of the structure. Therefore, the formation of SbH2 may depassivate the sample.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 92
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 1187-1196 
    ISSN: 0392-6737
    Schlagwort(e): Optoelectronic devices ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary In this paper we report on the frequency dependence of the AC conductivity of porous silicon in the range 10 Hz-100 kHz. Two types of testing devices have been fabricated on three different series of samples formed electrochemically using as a starting materialptype,n −-type andn +-type silicon substrates. For frequencies less than 20-40 kHz the conductivity is found to follow a sublinear frequency dependence. This behaviour is typical of a carrier transport mechanism determined by an anomalous diffusion process. At higher frequencies we find that surface states influence the transport mechanism. This suggests a double-channel transport mechanism: one related to porous-silicon “volume” properties and the other more connected to the “surface” itself.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 93
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 1197-1204 
    ISSN: 0392-6737
    Schlagwort(e): Optoelectronic devices ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary I–V DC characteristics have been measured on metal/ porous-silicon structures. In particular, the measurements on metal/ free-standing porous-silicon film/metal devices confirmed the result, already obtained, that the metal/poroussilicon interface plays a crucial role in the transport of any device. Four-contacts measurements on free-standing layers showed that the current linearly depends on the voltage and that the conduction process is thermally activated, the activtion energy depending on the porous silicon film production parameters. Finally, annealing experiments performed in order to improve the conduction of rectifiyng contacts, are described.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 94
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 1205-1212 
    ISSN: 0392-6737
    Schlagwort(e): Optoelectronic devices ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary Porous-silicon-based white-light-emitting devices are presented. The fabrication process on different substrates is described. The peculiarities of technological steps for device fabrication (porous-silicon formation and aluminum treatment) are underlined. Doping profile of the porous layer, current-voltage characteristics, time response, lifetime tests and electroluminescence emission spectrum of the device are presented. A model for electrical behaviour of Al/porous silicon Schottky junction is presented. Electroluminescence spectrum of the presented devices showed strong similarities with white emission from crystalline silicon junctions in the breakdown region.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 95
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 329-336 
    ISSN: 0392-6737
    Schlagwort(e): Kinetics of defect formation and annealing ; Alloys ; Mössbauer effect ; other γ-ray spectroscopy ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary Point defects in annealed B2-phase FeAl samples in the range 47–53 at.% Fe were studied using57Fe Mössbauer spectroscopy. Spectra were analyzed using local environment models according to which point defects in atomic shells close to probe atoms induce shifts in the nuclear monopole interaction. For well-annealed samples, better results were obtained assuming only the presence of FeAl antisite and VFe vacancy defects, and not of AlFe antisite defects. Monopole interactions of57Fe probes on the Fe and Al sublattices having no defects in the first two shells were about +0.27 and −0.03 mm s−1, respectively, with respect to Fe in alpha-Fe metal. The shifts induced by FeAl and VFe defects in the first shells of Fe probes on the Fe and Al sublattices were −0.15 and −0.24 mm s−1, respectively, and, in the second shells, +0.06 and +0.011 mm s−1. In addition to structural defects needed to accommodate deviations from stoichiometry, annealed samples were found to contain several percents of FeAl and VFe defects due to lattice disorder, with greater disorder in Fe-deficient alloys.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 96
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 353-357 
    ISSN: 0392-6737
    Schlagwort(e): Mössbauer spectra ; Spectra ; photodissociation and photoionization of biomolecules ; bioluminescence ; Measurement of rate constants ; reaction cross-sections and activation energy ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary Partial photodissociation of two carbonmonoxy-porphyrin complexes, a bridged and a fenced one, has been achieved. The results from monitoring the recombination point to an important influence of the solvent matrix on the recombination rates.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 97
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 375-379 
    ISSN: 0392-6737
    Schlagwort(e): Phonons and vibrations in crystal lattices ; Nuclear resonance fluorescence ; Synchrotrons ; Mössbauer effect ; other γ-ray spectroscopy ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary The Nuclear-Resonance Beamline at ESRF is dedicated to the excitation of nuclear levels by synchrotron radiation. The source of radiation and optical elements are optimized to provide an intense, highly monochromatic, collimated and stable X-ray beam of small cross-section at the Mössbauer transition energies between 6 keV and 30 keV. The set-up of the beamline allows to perform studies in diffraction, small-angle scattering, forward scattering and incoherent scattering. Equipment is available to maintain the sample at variable temperature and magnetic field. Fast detectors and timing electronics serve to separate the delayed nuclear scattering from the «prompt» electronic scattering and to measure the time spectra of nuclear radiation with sub-nanosecond resolution. The general layout and the parameters of the beamline are reported. Typical domains of applications are discussed and illustrated by first experimental results.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 98
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 199-212 
    ISSN: 0392-6737
    Schlagwort(e): Molecular biophysics ; Nuclear quadrupole resonance (NQR) ; Mössbauer spectra ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary A self-consistent description of the EPR spectra and of the Mössbauer spectra of the natural superoxide dismutase fromPropionibacterium shermanii with ferric iron as an active centre is presented. The spectra were measured atpH 6.5, 7.8 and 9.4. The theoretical approach is based on the use of the complete crystal field Hamiltonian for the high-spin ferric complexes with due regard for the terms of the fourth power of the electronic spin. It is shown that a SOD molecule can exist in two conformations. The low-pH conformation has predominantly trigonal symmetry, while the high-pH conformation has the symmetry close to the «extreme rhombic». This interpretation is in full agreement with EXAFS structural data.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 99
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 305-311 
    ISSN: 0392-6737
    Schlagwort(e): Magnetic properties of monolayers and overlayers ; X-ray, Mössbauer and other γ-ray spectroscopic analysis methods ; Mass spectrometry (including, SIMS, multiphoton ionization and resonance ionization mass spectrometry) ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary The composition of differently prepared Langmuir-Blodgett multilayers of ferric arachidate has been investigated by means of absorption Mössbauer spectroscopy and heavy-ion-induced mass spectrometry. We found that the iron concentration in qualitatively good films is 3.5 times higher than the stoichiometric value. Antiferromagnetic ordering in this two-dimensional model substance can be observed when the Fe−Fe distance in the layers is about 0.3 nm or below. The area density of the iron atoms in the planes decreases with decreasingpH values of the subphase which also leads to a disappearance of the long-range magnetic ordering and to a decrease of the Debye temperature of the films which is linearly dependent on the iron concentration in the films.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 100
    Digitale Medien
    Digitale Medien
    Springer
    Il nuovo cimento della Società Italiana di Fisica 18 (1996), S. 213-220 
    ISSN: 0392-6737
    Schlagwort(e): Mössbauer effect ; other γ-ray spectroscopy ; X- and γ-ray instruments and techniques ; Conference proceedings
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Summary The use of synchrotron radiation to excite low-lying nuclear resonances is a rapidly developing field showing great promise for hyperfine spectroscopy, phonon spectroscopy and kinetic studies, crystallography, and fundamental physics experiments. Recent technical advances in synchrotron sources, optics, and fast detectors have drastically increased signal rates and expanded the range of samples that can be studied. A typical experiment today uses a high-brightness synchrotron source having X-ray pulses well-separated in time, a meV-bandpass monochromator using perfect crystals of silicon or germanium, a sample containing resonant nuclei, and an avalanche photodiode timing detector. Both coherent and incoherent scattering can be observed; the coherent scattering is used for hyperfine spectroscopy and studies of diffraction interference phenomena, and the incoherent-scattering signal promises to be very useful for phonon spectroscopy and other studies of excitations in condensed systems. At this point seven nuclear isotopes have been used to resonantly scatter synchrotron radiation, but the number is rapidly increasing.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...