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  • 1990-1994  (925)
  • 1985-1989
  • 1994  (925)
  • Computational Chemistry and Molecular Modeling  (508)
  • Conference proceedings  (179)
  • Immunohistochemistry  (156)
  • Life Sciences (general)
Material
Years
  • 1990-1994  (925)
  • 1985-1989
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Rheumatology international 13 (1994), S. 181-186 
    ISSN: 1437-160X
    Keywords: Rheumatoid arthritis ; Immunohistochemistry ; Enzyme histochemistry ; Histopathology ; Chronic synovitis ; Macrophages
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rheumatoid arthritis (RA) is an inflammatory disease of the synovial membrane, which results in the destruction of joints by inflammatory pannus. The synovial membrane shows proliferation and cellular infiltrates on microscopy with signs of chronic and acute inflammation. Macrophages are thought to play a central role in the pathogenesis of RA. We examined synovial membrane specimens of 21 RA patients using morphological, immunohistological and enzyme histochemical methods for number and distribution of macrophages. We were able to identify 41.5±8.8% of lining cells as macrophages, depending on the method used. In abundant diffuse lymphocellular infiltrates, 23.4±11.1% of mononuclear cells were macrophages. In addition, most cells in the region of tumorlike proliferation and a stromal population of fibroblastlike cells were detected by macrophage markers. Although cell number in synovial membrane increases drastically, we did not find correlations between the relative amount of macrophages in these regions and basic activity. Basic activity includes proliferative reaction as well as lymphoplasmacellular and mononuclear infiltration-both signs of an immunopathological process. In contrast, using enzymes or activation markers, there was a clear correlation. We consider that a constant high percentage of macrophages in RA synovial membrane is present regardless of any actual in flammatory process.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Amino acids 6 (1994), S. 1-13 
    ISSN: 1438-2199
    Keywords: Amino acids ; β-Thymosins ; Phylogenetic distribution ; Actin sequestration ; Immunoassays ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary β-Thymosins, a group of highly homologous peptides consisting of about 40 amino acid residues, were found to be distributed from mammals up to echinoderms. Althogh they have first been isolated from mammalian thymus tissue preparations, their occurrance is not organ-specific and they are present even in different types of cells. For thymosinβ 4 several biological activities have been reported, stating that this peptide acts as a thymus peptide hormone and is also involved in the neuroendocrine and immune system. However, it was recently demonstrated that thymosinβ 4 has actin-sequestering properties and therefore might play an important role in the regulation of the microfilament system. This fact gives a new outlook on the real biological function ofβ-thymosins.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1437-1596
    Keywords: Asphyxia ; Strangulation ; Carotid body ; Immunohistochemistry ; Asphyxie ; Strangulation ; Glomus caroticum ; Immunhistochemie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Description / Table of Contents: Zusammenfassung Mit Hilfe immunhistochemischer Färbemethoden wurden die histologischen Veränderungen und das Vorhandensein von Neuropeptiden (Enkephalin und VIP) im Glomus caroticum bei rechtsmedizinischen Autopsie-Fällen, speziell bei Asphyxie-Fällen, untersucht. Lediglich in Fällen von manueller und werkzeugbedingter Strangulation, in denen die Gewalt in der Nähe des Glomus caroticum erlitten wurde, waren die Hauptzellen hauptsächlich leicht angefärbt, als Hinweis, daß sie „aktive” Zellen darstellten. Weiterhin waren diese Zellen und ihre Kerne vergrößert im Vergleich zu den Hauptzellen des Glomus caroticum in anderen Autopsie-Fällen. Es entstand daher der Eindruck, daß diese Veränderungen resultierten aus der Gewalt, die direkt das Glomus caroticum traf. Aufgrund dieser Befunde wurde geschlossen, daß die immunhistochemische Untersuchung des Glomus caroticum eine nützliche Möglichkeit darstellt, um die manuelle Asphyxie zu diagnostizieren, speziell in Autopsie-Fällen unter Einbeziehung der Strangulation.
    Notes: Summary Using immunohistochemical staining, the histological changes and the presence of neuropeptides (enkephalin and VIP) in the carotid body have been investigated in medico-legal autopsy cases, especially asphyxia cases. Only in cases of manual and/or ligature strangulation cases that sustained a force near the carotid body, were the chief cells mainly lightly stained, indicating that they had been “active” cells. Furthermore, these cells and their nuclei were enlarged in comparison to the chief carotid body cells in other autopsy groups. It was thus felt that these changes had resulted from the force that had directly affected the carotid body. Based on these findings, it was concluded that immunohistochemical investigation of the carotid body offers a useful possibility for diagnosing manual asphyxia, especially in autopsy cases involving strangulation.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    International journal of legal medicine 107 (1994), S. 69-76 
    ISSN: 1437-1596
    Keywords: Hypoxic/ischemic brain damage ; Immunohistochemistry ; Neurons ; Heat shock protein ; Glial cel ; Hypoxisch-ischämischer Hirnschaden ; Immunohistochemie ; Neuron ; Hitzeschock-Protein ; Gliazelle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Description / Table of Contents: Zusammenfassung Eine neuropathologische Studie von 41 forensischen Autopsie-Fällen mit hypoxischen/ischämischen Hirnschäden wurde durchgeführt, um das 70-kDA Hitzeschock-Protein (hsp70) und den Zustand der Gliazellen zu untersuchen. In Fällen, in denen der hypoxisch-ischämische Schaden 2–5 Stunden überlebt wurde, waren ischämische Schäden erkennbar, während Glia-Reaktionen noch nicht vorhanden waren. In Fällen längerer Überlebenszeit war ein neuronale Nekrose und ein Verlust von Neuronen zu beobachten, und diese Veränderungen waren begleitet von einer Proliferation des glialen fibrillären sauren Proteins (GFAP), der Vimentin-positiven Astrozyten und der Mikro-Glia, welche in stabförmige Zellen oder lipidbeladene Makrophagen transformierte. In Fällen mit einer Anamnese von hypoxischen Attacken war eine Proliferation GFAP-positiver und Vimentin-negativer Astrozyten in der CA3- und CA4-Region des Hippocampus zu beobachten. Die Fälle mit schwerem hypoxschämischen Schaden, wie Asthma-Anfall und Strangulation, zeighten keine ischämischen Veränderungen in den Neuronen des Hippocampus. Andererseits zeigten die CA 1-Pyramiden-Zellen bei einem Patienten mit Fallot'scher Tetralogie (TOF), welcher zwei Stunden nach einem Verkehrsunfall starb, eine neuronale Nekrose. Daher wird vermutet, daß auch weniger schwere hypoxische Schäden eine Astrozytose in der CA3- und CA4-Region induzieren und einen Einfluß haben dürften auf die neuronalen Proteine und auf den Metabolismus und daß in Fällen mit einer Anamnese hypoxischer Attacken der neuronale Schaden schwer sein kann, sogar mehrere Stunden nach dem ischämischen Schaden. Das Protein hsp70 wurde in den CA2-, CA3- und CA4-Regionen in Fällen langzeitigen Überlebens nach schweren hypoxischen/ischämischen Schäden gefunden und in Fällen, in denen kurz vor dem Tode eine Alkoholaufnahme oder Toluol-Mißbrauch stattfand. Daher wird vermutet, daß ein Nachweis hsp70 im Hypocampus eine hypoxischen Schaden oder einen anderen Streß kurz vor dem Tode an zeigt. In der forensischen Praxis sind die immunhisto chemische Untersuchung von hsp70 und Gliazell-Fär bungen von großer Bedeutung für die Diagnostik nicht nur des hypoxisch-ischämischen Hirnschadens während des Sterbeprozesses, sondern auch für die Diagnostik der Anamnese des Opfers im Hinblick auf hypoxische At tacken.
    Notes: Abstract A neuropathological study of 41 forensic autopsy cases of hypoxic/ischemic brain damage has been undertaken, using immunohistochemical staining to detect the 70-kDa heat shock protein (hsp70) and the status of the glial cells. In cases surviving 2–5 h after hypoxic/ischemic injury, ischemic cell changes were seen whereas glial reactions were not apparent. In cases of longer survival, neuronal necrosis and a loss of neurons were seen, and these changes were accompanied by proliferation of glial fibrillary acidic protein (GFAP), vimentin-positive astrocytes and microglia which transformed into rod cells or lipid-laden macrophages. In cases with a history of hypoxic attacks, GFAP-positive and vimentin-negative astrocytes had proliferated in the CA3 and CA4 regions of hippocampus. The cases of severe hypoxic injury, such as an asthmatic attack and choking, showed no ischemic changes in the hippocampul neurons. On the other hand, the CA1 pyramidal cells showed neuronal necrosis in a patient suffering from tetralogy of Fallot (TOF), who survived for 2 h after a traffic accident. Therefore, it is suggested that even moderate hypoxic injury induces astrocytosis in the CA3 and CA4 regions and may affect the neuronal proteins and the metabolism, and that in cases with a history of hypoxic attacks neuronal damage may be severe even several hours after ischemic injury. The protein hsp70 expression was found in the CA2, CA3 and CA4 regions in cases of long-term survival after severe hypoxic/ischemic injury and in cases of alcoholic intake or toluene abuse just before acute death. Thus, it is suggested that the detection of hsp70 in the hippocampus indicates hypoxic/ischemic injury or other stress prior to death. In forensic practice, immunohistochemical investigation of the hsp70 and glial cell staining can be of great value for diagnosing not only hypoxic/ischemic brain damage during the process of death but also the victim's past history of hypoxic attacks.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    International journal of legal medicine 106 (1994), S. 291-293 
    ISSN: 1437-1596
    Keywords: C5b-9(m) ; Immunohistochemistry ; Myocardial infarction ; Putrefaction ; Autolysis ; C5b-9(m) ; Immunhistochemie ; Myokardinfarkt ; Fäulnis ; Autolyse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Description / Table of Contents: Zusammenfassung C5b-9(m) ist ein spezifischer und sensitiver Marker für Myokardzellnekrosen. Sein diagnostischer Wert in der forensischen Praxis wäre aber stark eingeschränkt, wenn die immunhistologische Darstellung des Komplexes empfindlich gegen Autolyse und Fäulnis wäre. Wir konnten auch nach elftägiger experimentell forcierter Autolyse und Fäulnis C5b-9(m) immunhistochemisch in infarziertem Myokard sicher nachweisen. Zu diesem Zeitpunkt wäre die Diagnose eines Myokardinfarktes in der Hämatoxylin-Eosin-Färbung nicht mehr möglich gewesen. Im Untersuchungszeitraum waren falsch positive immunhistologische Färbungen nicht zu beobachten.
    Notes: Summary C5b-9(m) is a specific and sensitive marker for myocardial cell necrosis. The diagnostic value of this marker would be considerably limited in forensic practice if its immuno-histochemical demonstration were hampered by putrefaction or autolysis. We could demonstrate C5b-9(m) immunohistochemically in necrotic myocardium due to infarction up to the 11th day of experimentally induced putrefaction and autolysis, when reliable demonstration of myocardial infarction with hematoxylin-eosin was no longer possible. Under the experimental conditions of this study, no false positive immunohistochemical staining occurred.
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  • 6
    ISSN: 1437-9813
    Keywords: Nesidioblastosis ; Insulin ; Radioimmunoassay ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We present two cases of nesidioblastosis, a common cause of persistent hypoglycemia in infancy that, if inadequately treated, can lead to mental retardation. Tissue insulin data obtained from both radioimmunoassay and immunohistochemistry are presented. In each case, the insulin content correlated well with the quantity of insulinpositive cells in each portion of the pancreas. However, the insulin content varied from case to case and from portion to portion of the same pancreas. Thus, discrepancies in clinical results in nesidioblastosis may be due to variability of insulin content in the resected pancreas.
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  • 7
    ISSN: 1432-2307
    Keywords: Cytomegalic inclusion disease ; Viral replication ; Viral regulatory proteins ; Immunohistochemistry ; In situ hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Postmortem tissues from infants with congenital and postnatally acquired human cytomegalovirus (HCMV) infection were examined by routine histology, immunohistochemistry (IHC) and in situ hybridization (ISH) to determine the dynamics of viral replication in vivo. Histologically, infants in both groups showed characteristic inclusion-bearing cells most commonly in lung, kidney, liver and pancreas. IHC for late proteins using a rabbit polyclonal antibody and ISH for viral genomes detected most of the infected cells as nuclear and/or cytoplasmic signals. However, immunostaining with a monoclonal antibody against viral immediate early (IE) proteins was variable depending on the stage of viral replication within an individual infected cell. In tissues of infants with postnatal HCMV infection, many cells harboured IE antigens, while in tissues from congenital cases most of the affected cells lacked IE antigens and only a few showed cytoplasmic staining. The difference was not caused by the antigenic diversity among viral strains as confirmed by in vitro study. Our findings suggested that congenital infections exhibited uniformly late stage proteins with inactive viral replication at death, while acquired ones remained active. The different viral activity may reflect the immune status of congenital and acquired HCMV infections.
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  • 8
    ISSN: 1432-2307
    Keywords: C-kit product ; Immunohistochemistry ; Human normal tissue ; Small cell lung carcinoma ; Seminoma/dysgerminoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Eighteen hundred and eighty-four cases of human solid tumours and 833 samples of normal human tissues, formalin-fixed and paraffin-embedded, were examined immunohistochemically for expression of c-kit oncogene product using polyclonal antibody against synthesized c-kit peptide. Seminoma/dysgerminoma and small cell lung carcinoma (SCLC) show preferential c-kit expression at 92% and 36% frequency, respectively, whereas only sporadic cases of cervical carcinoma and non-SCLC lung carcinoma show c-kit positivity. A normal tissue counterpart positive for c-kit product is detected in the testis (spermatocyte) and ovary (oocyte) but not in the lung or the cervix. In contrast, normal epithelial cells of the breast, skin basal cells and tissue mast cells harbour c-kit product, but transformed cells of the former two are largely deficient in the c-kit protein. One hundred and thirty-nine neuroendocrine tumours and 39 non-pulmonary small cell carcinomas were all negative, except for two cases of neuroblastoma. This indicates a distinct character for SCLC in c-kit expression. The c-kit product may be a useful marker in diagnostic pathology of seminoma/dysgermona and SCLC among human solid tumours, and in distinction of SCLC from non-pulmonary small cell carcinoma.
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  • 9
    ISSN: 1432-2307
    Keywords: Cathepsin D ; Cathepsin E ; Rosai-Dorfman disease ; Langerhans' cell histiocytosis ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Nosological classification of sinus histiocytosis with massive lymphadenopathy (SHML; Rosai-Dorfman disease) is difficult, and the normal cellular counterpart of Rosai-Dorfman (RD) cells is uncharacterised. The peculiar S-100+ phenotype of RD cells suggests a relationship with the dendritic cell family. Recent investigations have revealed cathepsin E to be selectively concentrated in antigen-presenting cells, whereas cathepsin D was found to be expressed in cells of macrophage lineage. Cathepsin D and E distribution was investigated by immunohistochemistry in a series of SHML biopsies and in two types of dendritic cell proliferative lesions: dermatopathic lymphadenitis (DL) and Langerhans' cell histiocytosis (LCH). In SHML biopsies, RD cells and monocyte-related elements of the sinuses and pulp coexpressed cathepsin D and E. LCH cells also stained for both these aspartic proteinases. Conversely, in DL cathepsin E and D were localised to separate cells that resembled Langerhans' cells (LC) or macrophages, respectively, in morphology and distribution. Our data outline the peculiar immunophenotype of RD and LCH cells and suggest that caution should be exercised in the identification of their normal cellular counterpart. The common expression of cathepsin D and E and of S-100 protein suggests some phenotypic overlap between SHML and LCH cells, despite their striking morphological divergence.
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  • 10
    ISSN: 1432-2307
    Keywords: Bcl-2 protein ; Mesothelioma ; Pleura ; Immunohistochemistry ; Prognosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Immunohistochemical study of bcl-2 protein immunoreactivity in human non-neoplastic mesothelium (44 cases) and in malignant mesothelioma (62 cases) using a murine monoclonal antibody (clone 124) showed cytoplasmic immunoreactivity for bcl-2 protein in five cases of malignant mesothelioma. Non-neoplastic mesothelium was not immunoreactive. Immunoreactivity for bcl-2 protein does not add useful prognostic information in malignant mesothelioma since survival times of bcl-2 positive and bcl-2 negative cases did not differ. Nevertheless, the detection of bcl-2 protein in malignant mesothelioma might be useful for the differentiation from reactive mesothelium.
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  • 11
    ISSN: 1432-2307
    Keywords: Bcl-2 protein ; Mesothelioma ; Pleura ; Immunohistochemistry ; Prognosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Immunohistochemical study of bcl-2 protein immunoreactivity in human non-neoplastic mesothelium (44 cases) and in malignant mesothelioma (62 cases) using a murine monoclonal antibody (clone 124) showed cytoplasmic immunoreactivity for bcl-2 protein in five cases of malignant mesothelioma. Non-neoplastic mesothelium was not immunoreactive. Immunoreactivity for bcl-2 protein does not add useful prognostic information in malignant mesothelioma since survival times of bcl-2 positive and bcl-2 negative cases did not differ. Nevertheless, the detection of bcl-2 protein in malignant mesothelioma might be useful for the differentiation from reactive mesothelium.
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  • 12
    ISSN: 1432-2307
    Keywords: Cytokeratin Acute lymphoblastic leukaemia ; lymphoma ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report presents a case of common acute lymphoblastic leukaemia-lymphoma expressing low molecular weight cytokeratin but no leukocyte common antigen (CD45) in a 57-year-old man. The unusual morphology and clinical course together with the aberrant immunohistochemical results suggested a diagnosis of undifferentiated carcinoma. A detailed immunohistochemistry study on frozen and paraffin sections and molecular analysis prevented a diagnostic mistake.
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  • 13
    ISSN: 1432-2307
    Keywords: Breast ; Fibrous histiocytoma ; Giant cells ; Flow cytometry ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We describe a benign mammary mesenchymal tumour with atypical stromal giant cells in the contralateral breast of a 66-year-old woman with infiltrating ductal carcinoma. The clinical, morphological and immunohistochemical features of this tumour suggest a pleomorphic variant of fibrous histiocytoma. This benign lesion represents a possible pitfall in breast pathology when interpreting a frozen section or fine needle aspiration biopsy.
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  • 14
    ISSN: 1432-2307
    Keywords: Breast neoplasms ; Apocrine glands ; Immunohistochemistry ; Hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The frequency and the significance of apocrine differentiation in carcinomas of the breast are uncertain, because of the lack of reliable and reproducible criteria for morphological diagnosis. The 15 kDa glycoprotein of cystic breast disease (GCDFP-15) is regarded as a specific functional marker of apocrine cells. Expression of the prolactin-inducible protein (PIP)/GCDFP-15 gene was investigated by Northern blot analysis and in situ hybridization in breast cancer cell lines and in an unselected series (33 cases) of primary carcinomas of the breast. On the same cases, histological assessment of apocrine differentiation and immunocytochemical detection of GCDFP-15 were also performed and correlated with follow-up data. The presence of PIP/GCDFP-15 mRNA was a feature of a relatively high number of cases, but was incompletely correlated with histological and immunocytochemical evidences of apocrine differentiation. Expression of the PIP/GCDFP-15 gene was significantly associated with relapse-free survival, and may represent a novel variable of functional and prognostic relevance.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 424 (1994), S. 39-46 
    ISSN: 1432-2307
    Keywords: Proliferating cell nuclear antigen ; Immunohistochemistry ; Breast carcinomas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Proliferating cell nuclear antigen (PCNA), was examined by immunohistochemistry in 509 breast carcinomas. The immunoreactivity was found to be independent of the length of fixation when the tissue sections were microwaved before incubation with the primary antibody. The PCNA immunoreactivity was assessed by two semi-quantitative methods, which were correlated but not exchangeable. The comedo type of intraductal carcinomas and invasive ductal carcinomas had a higher PCNA score than other types. Lymph node metastases had a significantly higher PCNA score than primary carcinomas. High PCNA immunoreactivity was correlated with the presence of lymph node metastases, absence of tubule formation, numerous mitoses, severe nuclear pleomorphism, high histological grade and absence of progesterone receptors (PgR). PCNA in lymph node positive tumours was correlated with tumour type, especially with ductal carcinomas, absence of tubule formation, high histological grade and absence of PgR, whereas PCNA in lymph node negative tumours was correlated with large tumour size, numerous mitoses, severe nuclear pleomorphism and high histological grade. Number of mitoses and nuclear pleomorphism were the two most important factors in predicting the PCNA score; the absence of PgR and nuclear pleomorphism were important in lymph node negative and positive tumours, respectively. In a univariate analysis high PCNA score was found to be correlated with shorter relapse-free period and poorer over-all survival.
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  • 16
    ISSN: 1432-2307
    Keywords: v-src oncogene ; Rous sarcoma virus ; Fibrohistiocytic tumour ; Immunohistochemistry ; Southern blotting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The observation that v-src-induced tumors contain tumor cells of differing morphology, notably fibroblastoid or polygonal, raised the question as to whether the tumor cells are also heterogeneous with respect to expression of markers of cellular differentiation. Of the markers tested here, consistent reactivity for tumor tissue was noted only for antibody probes reactive to muscle actin (HHF35, αsm-1) or to procollagen type I (SP1. D8); for any given tumor, whether induced by v-src DNA or by Rous sarcoma virus, each of these markers was found only in a subpopulation of tumor cells. The observation of marker heterogeneity in the one v-src DNA-induced tumor examined here that typed as monoclonal suggests that v-src-induced transformation is consonant with a degree of plasticity in the phenotypes of the clonal progeny of a single transformant.
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  • 17
    ISSN: 1432-2307
    Keywords: Malignant fibrous histiocytoma ; Soft tissue sarcomas ; Immunohistochemistry ; Monoclonal antibody
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An immunohistochemical study on frozen sections was carried out on 51 malignant tumours of soft tissue and bone using the FU-3 monoclonal antibody. This antibody is claimed to be specific for malignant fibrous histiocytoma (MFH) and liposarcoma and for normal and tumour cells located in perivascular fields. The results show a lack of specificity in MFH staining: several malignant tumours such as synovial sarcoma, fibrosarcoma, rhabdomyosarcoma, osteogenic sarcoma, and including an anaplastic malignant melanoma, presented positive staining somewhat similar to that found in MFH. The value of this antibody in the differential diagnosis of MFH is doubtful. It might be useful to recognize a common pathway of terminal differentiation expressed by several pleomorphic sarcomatous neoplasms.
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 424 (1994), S. 267-271 
    ISSN: 1432-2307
    Keywords: Keratin ; Immunohistochemistry ; MNNG ; Oesophageal carcinoma ; Shrew
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The distribution of keratins in N-methyl-N'-nitro-N-nitrosoguanidine-induced oesophageal carcinomas in shrews was tested immunohistochemically, using a panel of seven different monoclonal antibodies. The studies were done on methacarn-fixed paraffin-embedded tissue, using the labelled streptavidin biotin method, and the relationship between morphological characteristics and keratin reaction patterns in carcinomas was analysed and compared with that in adjacent “normal” oesophageal epithelium. In the normal oesophageal epithelia, KL1, AE1, AE3, CK8.12 and CK4.62 stained suprabasal cells, 312C8-1 reacted to basal cells, and KS-1A3 labelled all epithelial cells. In squamous cell carcinomas, almost all the cancer cells were labelled strongly by 312C8-1 and weakly by KS-1A3, while a few cells in the centres of the keratinized foci were stained by KL1, AE1, AE3, CK8.12, and CK4.62. Like human oesophageal carcinomas, shrew oesophageal carcinomas maintain expression of human keratin 14, as determined by 312C8-1. The expression of human keratin 13, as determined by KS-1A3, was down-regulated.
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  • 19
    ISSN: 1432-2307
    Keywords: Gastric cancer ; Alpha-catenin ; Immunohistochemistry ; E-cadherin ; Cancer invasion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract E-cadherin (E-cad) plays a major role in the maintenance of cell-cell adhesion in epithelial tissues, and impaired E-cad expression correlates with tumour invasion and metastasis. Alpha-catenin (α-cat), an undercoat protein of adherens junctions, binds to the cytoplasmic domain of E-cad and is essential for linking E-cad to actin-based cytoskeleton. We investigated E-cad and α-cat expression in 60 human gastric cancers immunohistochemically. The 60 gastric cancers were classified into 18 (30%) in which α-cat expression was preserved, and 42 (70%) reduced cases. The reduction of α-cat expression was significantly related to dedifferentiation, depth of invasion, infiltrative growth and lymph node metastasis. We also examined the co-expression of α-cat and E-cad. Seventeen (28%) tumours preserved both molecules [α-cat(+)/E-cad(+)] and 33 (55%) tumours reduced both [α-cat(−)/E-cad(−)], whereas 9 (15%) tumours exhibited α-cat(−)/E-cad(+). The frequency of lymph node metastasis in α-cat(−)/E-cad(+) tumour (67%) was significantly higher than that in α-cat(+)/E-cad(+) tumours (24%) and was close to that in α-cat(−)/E-cad(−) tumours (82%). The frequency of haematogenous liver metastasis in α-cat(−)/E-cad(+) tumours (44%) was significantly higher than that in α-cat(+)/E-cad(+) tumours (6%) or α-cat(−)/E-cad(−) tumours (9%). Thus, in all E-cad(+) tumours, the frequency of lymph node and liver metastasis was higher in α-cat(−) tumours than in α-cat(+) tumours. α-Cat expression is apparently better at predicting tumour invasion and metastasis than E-cad expression.
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  • 20
    ISSN: 1432-2307
    Keywords: p53 ; Immunohistochemistry ; Breast cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To clarify whether p53 protein expression is involved in multistep carcinogenesis or the progression of mammary ductal carcinoma, we investigated p53 protein expression in 83 invasive ductal carcinomas (IDC), 10 IDC with a predominant intraductal component, 13 non-invasive ductal carcinoma (NIDC), 16 atypical ductal hyperplasia (ADH) and 39 benign epithelial hyperplasia (EH), using immunohistochemistry. Expression of p53 protein was detected in 24 (28.9%) cases of IDC, 5 (50%) cases of IDC with a predominant intraductal component and 1 (7.6%) case of NIDC. No expression was observed in either ADH or EH. In IDC, including cases with a predominant intraductal component, p53 protein expression was associated with a higher histological grade (P〈0.0001) or mitotic index (P〈0.0005). Although overexpression of c-erbB-2 protein has also shown a similar association with these prognostic indicators, expression of p53 protein correlated regardless of the status of c-erbB-2 overexpression. Completely coordinated expression of p53 protein was seen in both intraductal and invasive components. The intraductal component in IDC including cases with a predominant intraductal component which expresses p53 protein had significantly higher histological grade (P〈0.0005) or more comedo-subtypes (P〈0.0001). These results suggested that p53 protein expression occurs at a stage of NIDC with high histological grade or in comedo-subtypes. Its expression is maintained throughout invasion.
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  • 21
    ISSN: 1432-2307
    Keywords: Mesenchymoma ; Osteoclast ; Giant cell Malignant fibrous histiocytoma ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Three cases of malignant mesenchymoma with numerous osteoclast-like giant cells, arising in deep soft tissue, and which mimicked the so-called giant cell variant of “malignant fibrous histiocytoma” have been studied. All three neoplasms arose in adults; two patients were male and one was female. Two tumours arose in the thigh, and one in the right shoulder. Two patients died within 2 years of the primary excision while the third is alive and well at 2.5 years. Histologically, one case showed leiomyosarcoma plus liposarcoma, one leiomyosarcoma plus osteosarcoma, and one tumour consisted of liposarcoma plus osteosarcoma; all components were assessed morphologically as high-grade malignant. All three cases showed prominent osteoclast-like giant cells in the leiomyosarcomatous or osteosarcomatous areas, thereby closely mimicking the phenotype of so-called giant cell variant of “malignant fibrous histiocytoma”. We discuss briefly differences in soft tissue sarcomas demonstrating this distinctive osteoclast-rich phenotype.
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  • 22
    ISSN: 1432-2307
    Keywords: Thyroid ; Follicular tumour ; Oxyphilic cell tumour ; PCNA ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The expression of proliferative cell nuclear antigen (PCNA) in follicular tumours of the thyroid was examined by immunohistochemistry. Both usual nonoxyphilic cell follicular tumours (non-OCT) and oxyphilic cell tumours (OCT) were subdivided into benign, indeterminate, encapsulated carcinoma, and widely invasive carcinoma types. Among non-OCT the percentages of PCNA-positive cells in benign tumours, encapsulated carcinomas, and widely invasive carcinomas was 2.5%–8.6%, 11.8%–39.1%, and 18.6%–20.0%, respectively. There was a statistically significant difference between benign tumours and encapsulated or widely invasive carcinomas, as in previous studies. A value of 10% was appropriate to distinguish benign from malignant lesions. PCNA-positive cells in indeterminate-type non-OCT were not significantly different from those in benign tumours, ranging from 4.3%–19.6%, and occurring at more than 10% in three of six tuours. Among OCT the positivity was less than 10% in benign tumours (4.5%–7.8%) and more than 10% in malignant tumours (14.1%–35.9%) and all the eight indeterminate tumours (12.5%–27.3%), with a statistically significant differences between the benign tumour and each of the latter types. These results indicate that the examination of PCNA is valuable in diagnosis of thyroid follicular tumours and that the use of similar diagnostic criteria may be warranted in both non-OCT and OCT.
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  • 23
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    Virchows Archiv 425 (1994), S. 69-72 
    ISSN: 1432-2307
    Keywords: GLUT-1 Glucose transporter protein ; Immunohistochemistry ; Microvessel endothelium ; Hippocampus ; Alzheimer's disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Changes in cerebral microvessel ultrastructure have been reported to occur in Alzheimer's disease (AD). In order to investigate whether these changes are associated with compromised blood-brain transport mechanisms, hippocampal formation sections from AD and age-matched normal brains were immunolabelled with an antibody to the GLUT-1 glucose transporter protein. GLUT-1 immunolabelling of microvessel endothelium was significantly reduced in the AD compared to normal hippocampal formation. Thus, AD is associated with a reduction in cerebral microvessel endothelium glucose transporter content, which may result in decreased glucose availability to the brain.
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  • 24
    ISSN: 1432-2307
    Keywords: Endothelin-1 ; Adrenal gland ; Adrenal tumour ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Endothelin (ET)-1 is a 21-amino acid peptide with potent vasopressor and vasocontrictive properties. Biochemical studies suggest that this peptide occurs in adrenal glands, where it influences steroid hormone production. However, we have found no report of the topographical distribution of this peptide. The localization of ET-1 immunoreactivity in non-neoplastic (37 cases) and neoplastic adrenal glands (48 cases) was investigated with a sensitive immunohistochemical technique applied to routinely processed tissue specimens. ET-1 immunoreactivity was regularly seen in the cortex, especially in the zona fasciculata and to a varying extent also in the other two zones, but not in the medulla. The immunoreactive material appeared in the cytoplasm mostly in the form of vacuolar structures but also as grains. Focally, the cell membrane also showed immunoreactive staining. In the zona reticularis the immunoreactivity appeared mainly as cytoplasmic grains. Most cortical adenomas displayed numerous immunoreactive cells. The immunoreactivity in the tumour tissue appeared in the same forms as in normal cortex, but the reactive products were generally fewer in number. No obvious differences in immunostaining were seen between the aldosterone- and cortisol-producing adenomas or the non-functioning ones. Three of the ten carcinomas contained immunoreactive cells, but they were few, appearing focally and the ET-1 immunoreactive structures were seen as ‘dust-like’ material. The difference in immunoreactivity between the benign and the malignant cortical neoplasms may be of diagnostic value. Functionally our results support a relationship between ET-1 and steroid regulation in non-neoplastic cortical tissue.
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  • 25
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    Virchows Archiv 425 (1994), S. 315-320 
    ISSN: 1432-2307
    Keywords: Giant cell reparative granuloma ; Solid aneurysmal bone cyst ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Giant cell reparative granuloma (GCRG) is a reactive bone lesion that most often involves the jaws. However, occasional cases of GCRG in the distal extremities have been reported, to which we add five cases. All the patients were young to middle-aged adults and had sharply bordered, lytic lesions. Histologically, all the lesions had areas of osteoclast-like giant cells and osteoblast mantled osteoid. Two of the cases had foci of osteoclast-like giant cells lining vascular spaces. In extragnathic locations, GCRG may simulate other osteolytic giant cells lesions such as giant cell tumour of bone and aneurysmal bone cyst (AnBC). Immunohistochemically, all cases showed positive staining of the stromal spindle cells for vimentin and actin, and of the osteoclast-like giant cells for CD68, vimentin and leucocyte common antigen. GCRG is a benign lesion and conservative therapy is curative. As GCRG may have histological features which resemble AnBC it may be considered to be the solid variant of AnBC.
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  • 26
    ISSN: 1432-2307
    Keywords: Tenascin ; Stomach ; Hyperplasia Carcinoma ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Wie studied the expression of tenascin (Tn) in human stomach. In the normal mucosa of the antrum and body, Tn reaction was only seen in the muscularis mucosae, in the region of the pyloric sphincter and in the duodenum, a Tn-immunoreactive rim was seen underlying surface epithelial cells. Antral gastritis, irrespective of the degree of inflammation, showed a rim-like Tn expression under the surface epithelial cells but no Tn reaction was seen in mild chronic gastritis of the body. In some moderate and severe examples of chronic gastritis a delicate Tn-reactive line was seen to underline the surface epithelium focally and the neck regions of gastric pits. Discontinuous Tn immunoreactivity was sometimes seen beneath hyperplastic epithelium in both parts of the stomach. A Tn-immunoreactive line was seldom seen surrounding glands showing intestinal metaplasia. In both benign and malignant ulcers prominent Tn immunoreaction was seen at the base of ulcers extending deep into the underlying muscularis. Only severely dysplastic lesions displayed Tn in the lamina propria, in close association with capillaries. In early forms of diffuse gastric cancer (DGCA) raggedly increased Tn staining was seen in the lamina propria underlying affected surface epithelial cells. In advanced forms of DGCA consistent Tn expression was seen in the tumour stroma. A distinct Tn reaction was seen surrounding invasive tumour cell nests of intestinal type gastric cancer (IGCA) in the submucosa, whereas in early forms of the tumour enhanced Tn reaction was noted predominantly in the upper part of the lamina propria in the vicinity of dysplastic elements. Notably, while most invading DGCA tumour cell nests showed no Tn in the submucosa and muscle cell layer, invading IGCA islets showed prominent expression of Tn. The most conspicuous Tn enhancement in the stomach is seen in invasive tumours and in ulcers suggesting that Tn is an important stromal component in malignant growth and in lesions undergoing active repair and remodelling.
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  • 27
    ISSN: 1432-2307
    Keywords: Primary retroperitoneal mucinous cystoadenocarcinoma ; Immunohistochemistry ; K-ras mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Special immunohistochemical stains for the identification of gastroenteropancreatic antigens in two cases of primary retroperitoneal mucinous cystoadenocarcinomas (PRMC) show that these tumours have patterns similar to ovarian mucinous tumours. Markers of pyloric type gastric mucosa differentiation (M1, cathepsin E, concavavalin A, pepsinogen II) are mostly positive in benign and borderline areas with endocervical type differentiation, while immunoreactivity for intestinal cell markers (M3SI and CAR-5) and for DU-PAN-2 is present mainly in frankly malignant areas, regardless of differentiation type. DNA analysis shows a point mutation of K-ras oncogene at codon 12 (GGT to CGT) in one case. The immunohistochemical and genotypic similarity of PRMC and ovarian mucinous tumours may indicate similar mechanisms in their histogenesis.
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  • 28
    ISSN: 1432-2307
    Keywords: Adenocarcinoma ; Immunohistochemistry ; Tumour suppressor gene ; Ethnicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Gastric cancer is more than twice as common in Hispanics as in Anglos in Texas, while colorectal cancer is almost twice as common in Anglos as Hispanics. To test the hypothesis that mutations in the p53 tumour suppressor gene are involved in these differences, we examined 131 gastric and 138 colorectal cancers from Hispanic and Anglo patients from South Texas and Mexico using immunohistochemistry (IHC) as a screening assay for p53 mutations. The fraction of p53 positive cases was not significantly different in gastric cancers from Hispanics compared to Anglos (43% versus 61%, respectively, p=0.13) or in colorectal cancer (57% versus 58%, respectively, p=1.0), suggesting that p53 mutations are not involved in causing the different incidences of these cancers in these populations. In addition, the types of p53 mutations arising in gastric tumours from Hispanic patients were consistent with those reported in gastric tumours in other populations. Sequencing of mutations in five gastric cancers revealed two G: C to A: T transitions, two A: T to G: C transitions and one complex deletion. In contrast with findings in studies in other tumour types, neither stage nor survival was associated with p53 positive staining by IHC in either gastric or colorectal tumours in this study. Positive p53 immunostaining was associated with the diffuse histological subtype in gastric carcinoma (p=0.05) and high histological grade in colorectal carcinoma (p=0.04).
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  • 29
    ISSN: 1432-2307
    Keywords: L-pyruvate kinase ; M2-pyruvate kinase ; Kidney neoplasms ; Carbohydrate metabolism ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Using immunohistochemical and enzyme biochemical methods we investigated the expression of L- and M2-pyruvate kinase (PK) in normal renal tissue, renal cell carcinomas (RCCs; of clear cell, chromophilic cell and mixed cell type) and RCC metastases. L-PK was expressed in the proximal tubules of normal renal tissue and, to a variable extent, in 23/25 primary RCCs, in 1 RCC recurrence and in 10 RCC metastases. Staining intensity and percentage of stained tissue did not correlate with tumour grade. One renal oncocytoma and all extrarenal malignancies examined lacked L-PK immunoreactivity. M2-PK was mainly expressed in the distal tubules of the normal kidney and was found in all renal tumours as well as extrarenal malignancies. Quantitative biochemical investigations yielded a two- to seventeen-fold increase in PK activity in RCCs compared to the normal renal cortex taken from the same patient, whereas fructose-1,6-bisphosphatase and cytosolic glycerol-3-phosphate dehydrogenase activity was dramatically lower in RCCs. Otherwise, the activity of all other enzymes investigated (glucose-6-phosphate dehydrogenase, enolase and lactate dehydrogenase) was not significantly changed in the RCCs. The immunocytochemical results suggest that L-PK is a useful marker for RCC and its metastases, if acetone-fixed tissue is available. The quantitative changes of the concentration of PK and other enzymes in RCCs when compared with normal renal tissue probably reflect metabolic alterations related to tumour growth.
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  • 30
    ISSN: 1432-2307
    Keywords: Pulmonary artery ; Neoplasm ; Sarcoma ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Herein we report the clinicopathological features of four cases of pulmonary artery sarcoma that appeared at our institution during a period of 30 years. The patients, 2 males and 2 females, were 50–62 years old. Tumour was found in the pulmonary trunk and right pulmonary artery in all cases, in the pulmonary valve and left pulmonary artery in three of the four cases, and in the right ventricular outflow tract in one case. There was direct extension or metastases to the lungs in two cases, the heart in one case, mediastinum or lymph nodes in two cases and the pleura in one case. Ultrastructural examination in one case revealed cells with features of smooth muscle cells and myofibroblasts. Immunohistochemical examination of three cases gave the following results: vimentin and smooth muscle specific actin was positive in all three cases, desmin in one case and cytokeratin in one case. No positivity was found for Factor VIII. This and other studies indicate that histologically most pulmonary artery sarcomas are leiomyosarcomas or “undifferentiated spindle cell sarcomas”. Immunohistochemical and ultrastructural examinations favour an origin from myofibroblasts, probably derived from multipotent (undifferentiated) cells in the wall of the vessel. Most lesions show extensive intrathoracic growth although they rarely metastasize outside the thoracic cavity. They have a poor prognosis although some cases are currently being diagnosed during life.
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  • 31
    ISSN: 1432-2307
    Keywords: Extracellular matrix ; Immunohistochemistry ; Squamous cell carcinoma ; Invasiveness ; Metastasis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The expression of extracellular matrices (ECMs) laminin (LN), type IV collagen (IV C), heparansulphate proteoglycan (HS-PG), fibronectin (FN), tenascin (TN), decorin and vitronectin (VN) was examined immunohistochemically in 112 primary tumours and 29 metastatic cervical lymph nodes in oral squamous cell carcinoma (OSCC). In highly invasive primary tumours, the expression of LN, IV C and HS-PG in the basement membrane along the tumour-stroma borderline and the expression of decorin and VN in the tumour stroma at the invasive site were all significantly decreased. The expression of FN and TN in the tumour stroma at the same site was markedly increased. In peritumour stroma in metastatic lymph nodes, LN, IV C, HS-PG, decorin and VN were weakly expressed, while FN and TN were strongly expressed. Thus, the staining pattern of the ECMs in the metastatic lymph nodes was similar to that in highly invasive primary tumours. Furthermore, in primary tumours of metastatic cases, the expression of LN, IV C, HS-PG, decorin and VN obviously decreased, while the expression of FN and TN increased when compared with those of the non-metastatic cases. The investigation of ECMs in OSCC was valuable in predicting tumour behaviour.
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  • 32
    ISSN: 1432-2307
    Keywords: Cathepsin D ; Cathepsin E ; Rosai-Dorfman disease ; Langerhans' cell histiocytosis ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Nosological classification of sinus histiocytosis with massive lymphadenopathy (SHML; Rosai-Dorfman disease) is difficult, and the normal cellular counterpart of Rosai-Dorfman (RD) cells is uncharacterised. The peculiar S-100+ phenotype of RD cells suggests a relationship with the dendritic cell family. Recent investigations have revealed cathepsin E to be selectively concentrated in antigen-presenting cells, whereas cathepsin D was found to be expressed in cells of macrophage lineage. Cathepsin D and E distribution was investigated by immunohistochemistry in a series of SHML biopsies and in two types of dendritic cell proliferative lesions: dermatopathic lymphadenitis (DL) and Langerhans' cell histiocytosis (LCH). In SHML biopsies, RD cells and monocyte-related elements of the sinuses and pulp coexpressed cathepsin D and E. LCH cells also stained for both these aspartic proteinases. Conversely, in DL cathepsin E and D were localised to separate cells that resembled Langerhans' cells (LC) or macrophages, respectively, in morphology and distribution. Our data outline the peculiar immunophenotype of RD and LCH cells and suggest that caution should be exercised in the identification of their normal cellular counterpart. The common expression of cathepsin D and E and of S-100 protein suggests some phenotypic overlap between SHML and LCH cells, despite their striking morphological divergence.
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  • 33
    ISSN: 1432-2307
    Keywords: Intermediate filament proteins ; Cervix ; Neoplasia ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We investigated the expression of keratin subtypes 7, 8, 10, 13, 14, 17, 18 and 19 in the normal cervix, in cervical intraepithelial neoplasia (CIN) lesions and in cervical carcinomas, using a selected panel of monoclonal keratin antibodies, reactive with routinely processed, formalin fixed paraffin embedded tissue fragments. The reaction patterns derived for each keratin antibody were compared with known expression patterns of the various epithelia, previously examined in frozen tissues. Although the reactivity of the antibodies was generally acceptable, considerable modifications to the manufacturers' staining instructions were often necessary. For some antibodies, which were previously thought to be reactive with fresh frozen tissue only, we developed staining protocols rendering them reactive with routinely processed material. As with previous findings in frozen sections we observed increasing expression of keratins 7, 8, 17, 18 and 19 with increasing grade of CIN. In cervical carcinomas the differences in keratin detectability between the main categories were more pronounced than in frozen sections, probably due to fixation and processing. For routine pathology, keratin phenotyping of cervical lesions may be of value in classification. The fact that keratin 7 was detected for the first time in reserve cells, and that this keratin was also found to be expressed in a considerable number of CIN lesions and cervical carcinomas supports the suggestion that reserve cells are a common progenitor cell for these lesions.
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  • 34
    ISSN: 1432-2307
    Keywords: Metallothionein ; Immunohistochemistry ; Colorectal cancer ; Prognosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Metallothioneins (MTs), a set of ubiquitous low-molecular-weight proteins essential for the protection of cells against heavy metal ion toxicity, were demonstrated immunohistochemically using a monoclonal antibody (E9) against a conserved epitope of I and II isoforms in a series of 109 colorectal adenocarcinomas. In a semiquantitative analysis strong MT expression in the majority of tumour cells was observed in 34 (31%) cases, 24 (22%) tumours showed a focal MT positivity, and 51 (47%) almost completely lacked MT expression. These differences in MT expression were statistically significantly (P〈0.05) associated with the tumour stage (Dukes classification) and the lymph node involvement at the time of operation (pN stages). However, in contrast to previous findings obtained on a variety of tumours, MT positivity was associated with a favourable clinical outcome in colonic carcinoma, which may indicate their different biological behaviour. Survival curves of cases with MT-positive and MT-negative status differed from each other in a univariate analysis (Mantel-Haenszel: 8.9, P〈0.05) but lost significance when a multivariate analysis was carried out by means of the Cox proportional regression model with Dukes' stages as a stratification factor. It is concluded that immunohistochemically demonstrated MT expression is significantly associated with tumour stages but does not represent an independent prognostic variable in colorectal cancer. However, it may provide important information about some of the biological mechanisms underlying progression in colorectal cancer.
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  • 35
    ISSN: 1434-0879
    Keywords: Urological diseases ; Epidermal growth factor ; Epidermal growth factor receptor ; Transitional cell carcinoma ; Nephrectomy ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To examine the excretion of urinary epidermal growth factor (EGF) in urological diseases and the relationship of EGF urine levels with transitional cell carcinoma (TCC), we measured the concentration of EGF by radioimmunoassay. The series comprised patients with active TCC (n=50), others in tumor-free status (n=29) and with non-neoplastic inflammatory diseases (n=43), and normal controls (n=50). Urinary EGF values were lower in patients with urological diseases of different etiologies than in normal controls (P〈0.005). Mean EGF levels of patients who had previous bladder tumor resection (n=21) were not statistically different from normal controls (P=0.2). For patients with active TCC, EGF urine levels showed a significant inverse relationship to increasing tumor grade (P=0.02). In addition, subjects who had received nephrectomy for pelvic carcinoma (n=8) showed significantly lower mean EGF values than those with intact kidneys (n=21), irrespective of sex (P〈0.05). Immunostaining of EGF on non-neoplastic kidney (n=9) revealed reactivity in the distal convoluted tubules and thick ascending limbs of Henle. Our results suggest that the kidney is the major source of urinary EGF. Its excretion in urine is decreased in both inflammatory and neoplastic diseases of the urinary tract. EGF may play an important part in the biological activity of TCC. Further study is indicated to investigate the monitoring of EGF urine levels as a marker of recurrence for EGF receptor-positive TCC.
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  • 36
    ISSN: 1432-0533
    Keywords: Key words: Manganese superoxide dismutase ; Amyotrophic lateral sclerosis ; Free radical ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Neuronal expression of manganese superoxide dismutase (MnSOD) in sporadic amyotrophic lateral sclerosis (sALS) was investigated by an immunohistochemical method. The brains and spinal cords from 11 patients with sALS and 20 normal controls (NCs) were used, and the following four nuclei (three motor nuclei and one autonomic nucleus) were examined: the oculomotor nucleus; the hypoglossal nucleus; the cervical motor nucleus ; and Onuf's nucleus. Serial sections were stained by the Klüver-Barrera (KB) method and with human-MnSOD-specific antibodies. We counted the total number of neurons visible after KB staining and the total number of positive neurons after immunostaining. The average total number of neurons after KB staining was similar in sALS patients and NCs in both the oculomotor nucleus and Onuf's nucleus, but the number in the hypoglossal and cervical motor nuclei was significantly lower in sALS. The ratio of MnSOD-positive neurons to total neurons visible after KB staining, calculated as an index of the expression of MnSOD, was significantly higher in the oculomotor nucleus and Onuf's nucleus, and lower in the hypoglossal nucleus in sALS patients than in NCs. In the cervical motor nucleus, the ratio in sALS patients did not differ from that in NCs. These results suggest that production of toxic superoxide radicals might be increased in sALS, and that neurons that successfully induce the expression of sufficient MnSOD can survive the disease process, while those failing to activate adequate expression of the enzyme succumb to the toxic effects of the radicals and die.
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  • 37
    ISSN: 1432-0533
    Keywords: Mitochondrial myopathy ; Ragged red fibers ; In situ hybridization ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In situ hybridization combined with immunohistochemical techniques has been applied to study patients affected by mitochondrial myopathies with large mitochondrial (mt)DNA deletions. All patients' muscle biopsies showed ragged red fibers (RRFs) and cytochrome oxidase (COX) deficiency. Two digoxygenin-labeled, polymerase chain reaction (PCR)-amplifed DNAs were used as probes. One probe was designed to hybridize only with wild-type mtDNAs, while the other recognized both wild-type and deleted mtDNAs. Concomitant immunocytochemical analysis using antibodies against subunits II, III, (encoded by mtDNA) and IV (encoded by nuclear DNA) of COX was carried out. In our patients deleted mtDNAs are overexpressed in COX-negative RRFs, while wild-type mtDNAs are decreased in the same fibers. Immunohistochemistry studies show that COX IV is overexpressed in RRFs and that COX II and COX III subunits are still present. Deleted mtDNAs are spatially segregated in muscle fibers, where they interfere with the local population of normal mitochondrial genomes, causing a regional deficiency of the mitochondrial respiratory activity.
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  • 38
    ISSN: 1432-0533
    Keywords: Key words Round granulated body ; Eosinophilic ; hyaline droplets ; Astrocytic tumors ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Round granulated body (RGB) and eosinophilic hyaline droplets (EHDs) have been described as cytoplasmic inclusions of certain astrocytic tumors. In the previous literature, however, these inclusions have been described using various terms or regarded as nosologically the same entity. Light microscopically, RGB appeared as a round discrete body filled with fine uniform granules, while EHDs demonstrated a cluster of bright eosinophilic, round objects of various size. They could be clearly distinguished even by conventional histochemical staining such as the Masson trichrome stain and the phosphotungstic acid hematoxylin preparation. Both RGB and EHDs expressed positive immunoreactions for glial fibrillary acidic protein, several lysosomal markers, and some stress-response proteins. The ultrastructural appearances of these inclusions were distinct, however, one common feature was that they consisted of aggregations of numerous membrane-bound electron-dense bodies. Thus, both inclusions appear to be produced by neoplastic astrocytes and are possibly related to the lysosomal system. We examined the presence of RGB and EHDs in 138 astrocytic tumors. Both inclusions occurred most frequently in pleomorphic xanthoastrocytomas, followed by gangliogliomas and pilocytic astrocytomas. Subependymal giant cell astrocytomas exhibited only RGBs. RGBs and EHDs were not seen in any abundance in glioblastomas, gliosarcomas, fibrillary astrocytomas, protoplasmic astrocytomas, or oligo-astrocytomas. Some glioblastomas, however, showed only EHDs in small numbers. Several anaplastic astrocytomas were associated with a large number of RGBs and/or EHDs, and they revealed only rare mitosis despite marked cellular pleomorphism. Although RGB and EHDs have different morphological features, the presence of these inclusions in abundance may represent either a degenerative change, a long-standing lesion, or an indolent growth of the astrocytic tumors.
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  • 39
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    Acta neuropathologica 87 (1994), S. 398-404 
    ISSN: 1432-0533
    Keywords: Astrocyte cultures ; Brain stem infection ; Herpes simplex virus type 1 ; Immunohistochemistry ; Rat model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Infection of the CNS by herpes simplex type 1 (HSV-1) via the trigeminal route to the brain stem was elucidated in a rat model. In contrast to the earlier described cortical and hippocampal infection after intracranial injection, the CNS showed a profound resistance to HSV-1 infection when the virus was administred by nose inoculation, as judged by histopathology and immunohistochemistry. In contrast, when the distribution of HSV-1 in the brain was investigated after nose inoculation by polymerase chain reaction, viral DNA was detected at all levels from the ganglia to the cortex. When replication of HSV-1 was assayed in primary cell cultures of rat astrocytes derived from brain stem, striatum, hippocampus and cerebral cortex, significantly lower virus yields were obtained in brain stem-derived astrocytes cultures as compared with in cortex-derived astrocytes. This finding was independent of whether HSV-1 strains used originated from brains of patients suffering from herpes simplex encephalitis or from patients with oral cutaneous lesions and lacking neurological symptoms. Also, by immunocytochemistry of cultures after HSV-1 infection, a lower number of plaques were seen in brain stem-derived astrocytes as compared with cortex-derived astrocytes. The observed relative resistance of brain stem-derived astrocytes to replicate HSV-1 might contribute to the ability of the brain stem to withstand infection during reactivation of this virus in the trigeminal neurons.
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  • 40
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    Anatomy and embryology 190 (1994), S. 55-63 
    ISSN: 1432-0568
    Keywords: Neuropeptide Y ; Corpus callosum ; Development ; Transitory axons ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Many immunocytochemical studies have identified different types of neurotransmitters localized in the corpus callosum (CC) axons in the adult mammal. Few studies have looked at the development of different neurochemically identified CC systems. Previous studies on the development of cat CC axons have indicated that a large number of transitory CC axons project to the cortex during early postnatal development. The present study focuses on the development of one neurochemically identified group of CC axons in the cat, labeled with an antibody against neuropeptide Y (NPY), to determine if this group participates in transitory CC axonal growth. Cats at specified ages from birth to adulthood were studied with a routine method of immunocytochemistry for antiserum to NPY. NPY-immunoreactive (ir) CC axons were detected at all stages examined, from newborn to adult; the peak density occurred during postnatal weeks (PNW) 3–4. During PNW 1–2, the denisty of NPY-ir CC axons increased gradually; some NPY-ir axons at this age had growth cones located within the CC bundle between the cerebral hemispheres. The density of the NPY-ir CC axons decreased gradually during PNW 5–7, and from PNW 8 to maturity only a few NPY-ir CC axons were observed. These results indicate that at least two types of NPY-ir CC axons (i.e., transitory and permanent) exist during development, and that most of these axons are eliminated or only express NPY-ir for a short period during development. The results also indicate that neurochemical subsets of CC axons participate in the extensive transitory growth observed by means of the membrane tracer DiI but they may follow unique developmental timetables.
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  • 41
    ISSN: 1432-0533
    Keywords: Managanese superoxide dismutase ; Amyotrophic lateral sclerosis ; Free radical ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Neuronal expression of manganese superoxide dismutase (MnSOD) in sporadic amyotrophic lateral sclerosis (sALS) was investigated by an immunohistochemical method. The brains and spinal cords from 11 patients with sALS and 20 normal controls (NCs) were used, and the following four nuclei (three motor nuclei and one autonomic nucleus) were examined: the oculomotor nucleus; the hypoglossal nucleus; the cervical motor nucleus; and Onuf's nucleus. Serial sections were stained by the Klüver-Barrera (KB) method and with human-MnSOD-specific antibodies. We counted the total number of neurons visible after KB staining and the total number of positive neurons after immunostaining. The average total number of neurons after KB staining was similar in sALS patients and NCs in both the oculomotor nucleus and Onuf's nucleus, but the number in the hypoglossal and cervical motor nuclei was significantly lower in sALS. The ratio of MnSOD-positive neurons to total neurons visible after KB staining, calculated as an index of the expression of MnSOD, was significantly higher in the oculomotor nucleus and Onuf's nucleus, and lower in the hypoglossal nucleus in sALS patients than in NCs. In the cervical motor nucleus, the ratio in sALS patients did not differ from that in NCs. These results suggest that production of toxic superoxide radicals might be increased in sALS, and that neurons that successfully induce the expression of sufficient MnSOD can survive the disease process, while those failing to activate adequate expression of the enzyme succumb to the toxic effects of the radicals and die.
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  • 42
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    Acta neuropathologica 88 (1994), S. 454-458 
    ISSN: 1432-0533
    Keywords: Immunohistochemistry ; Meningioma ; Neurofibroma ; Schwannoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract CD34 is a sialylated transmembrane glyco-protein of unknown function that is present in myeloid progenitor cells, endothelial cells, and some fibroblastrelated mesenchymal cells. However, its tissue distribution is still incompletely characterized. In this study we evaluated the distribution of CD34 antigen in tumors of the central and peripheral nervous system. For comparison the tumors were also stained for CD31, also known as platelet-endothelium cell adhesion molecule (PECAM-1), a transmembrane glycoprotein so far considered to be endothelium specific beyond its reactivity with certain hematopoietic cells. Neurofibromas showed consistently high numbers of CD34-positive spindle cells, whereas peripheral and acoustic schwannomas were negative. A subset of meningiomas (15%) showed CD34-positive tumor cells, and some were also weakly positive for CD31. Gliomas were negative. Meningeal hemangiopericytomas were consistently CD34 positive, but CD31 negative. These results indicate a moderately widespread distribution of the CD34 antigen in nervous system tumors, and necessitate caution in making conclusions regarding endothelial cell differentiation of nervous system tumors on the basis of CD34 immunoreactivity.
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  • 43
    ISSN: 1432-0533
    Keywords: Immunohistochemistry ; Medulla oblongata ; Prion protein (PrP) ; Bovine spongiform encephalopathy ; Formalin-fixed tissue
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The efficacy of three pretreatment techniques for the detection of prion protein (PrP) in formalin-fixed, paraffin-embedded bovine spongiform encephalopathy (BSE)-affected brain tissue were compared using automated image analysis. The most abundant immunostaining was in the form of particulate expression observed in sections pretreated with hydrated autoclaving for 30 min. Considerably less immunostaining occurred in sections pretreated with formic acid and no specific particulate immunostaining was detected in sections pretreated with hydrolytic autoclaving. Hydrated autoclaving pretreatment of sections prior to PrP immunolabelling gives visualisation of widespread sites of abnormal PrP deposition in the brain, allowing detailed study of the form and distribution of the protein in routinely fixed bovine central nervous system affected with BSE.
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  • 44
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    Anatomy and embryology 189 (1994), S. 237-242 
    ISSN: 1432-0568
    Keywords: Thyroid cartilage ; Immunohistochemistry ; Mineralization ; Ossification ; Collagens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Thyroid cartilages of various ages were investigated by immunofluorescence staining for localization of the fibrillar collagen types I and II in order to understand the tissue remodeling occurring during the mineralization and ossification of thyroid cartilage. In fetal and juvenile thyroid cartilages, type I collagen was restricted to the inner and outer perichondrium, while type II collagen was localized in the matrix of hyaline cartilage. However, in advanced ages, type I collagen was also localized in the pericellular and in the interterritorial matrix of intermediate and central chondrocytes of thyroid cartilage. The matrix of peripheral chondrocytes was negative for type I collagen. This suggests that some chondrocytes in thyroid cartilage undergo a differentiation to type I collagen-producing chondrocytes. At the beginning of ossification, bone-related type I collagen was chiefly detected in the central cartilage layer, but was never deposited first from the perichondrium in the direction to the subperichondrial cartilage. This observation confirmed previous findings showing that osteogenesis mainly follows an endochondral ossification pattern. Interterritorial matrix failed to react with the type II collagen antibody in men from the beginning of the third decade, and later still in women, even after treatment with hyaluronidase. These observations indicate that major matrix changes occur faster in male than in female thyroid cartilage.
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  • 45
    ISSN: 1432-0533
    Keywords: Key words: Perineurial cells ; Nerve regeneration ; Immunohistochemistry ; Epithelial membrane antigen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Perineurial cells are specialized connective tissue cells that form a barrier between endoneurium and epineurium in normal nerves. In the present study, the formation of the perineurium after transection of rat sciatic nerves was investigated. The cord bridging the gap between proximal and distal stumps through silicone tubes was studied 3, 7, 12, 18, and 21 days after surgery using electron microscopy and antibodies against epithelial membrane antigen (EMA), a marker for perineurial cells that has thus far not been applied to the study of differentiating cells in nerve tubulation systems. Initially, a thin cord consisting of fibrin bridged the gap between the stumps. At 7 days, longitudinal cells had migrated from both stumps toward the center of the tubes on the surface of the fibrin cord. These cells were immunoreactive with anti-EMA. At 12 days, ultrastructural features of perineurial cells (desmosomes, tight junctions, actin filaments with dense bodies, tonofilaments) were prominent in these cells. Subsequently, the gap was bridged through the perineurial tube by endothelial cells, pericytes, fibroblasts, Schwann cells, and axons. At 21 days, a single large nerve fascicle ensheathed by a mature perineurium was found between the stumps. Thus, the first cells to connect proximal and distal stumps in the investigated nerve regeneration silicon chamber system are perineurial cells. Through the tube formed by these cells, blood vessels and nerve fibers bridge the gap. Therefore, establishment of a perineurial connection between nerve stumps appears to be important in the sequence of events during nerve regeneration.
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  • 46
    ISSN: 1432-0533
    Keywords: MyoD1 ; Myopathy ; Immunohistochemistry ; Neurogenic atrophy ; Werdnig-Hoffmann's disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The expression of the myogenic determination gene MyoD1 plays a primary role in the commitment of primitive mesenchymal cells to a striated muscle lineage and is down-regulated during later stages of differentiation. To determine the potential role of this gene in myopathic conditions, we examined its expression by means of immunohistochemical analysis, using a series of muscle biopsies from 14 patients with a variety of primary myopathies and neurogenic disorders. Utilizing the avidin-biotin-complex technique, cryostat sections were stained with monoclonal antibody 5.8 A, which we have previously described as having a high level of specificity for tumors with rhabdomyoblastic differentiation. Of special interest was the observation in 4 of 8 cases of neurogenic atrophy of varying levels of cytoplasmic positivity of muscle fibers, appearing to correlate with their degree of atrophy, in addition to weak nuclear staining. Muscle biopsies from 2 patients with Duchenne's muscular dystrophy and 2 patients with autoimmune inflammatory myopathies demonstrated various levels of nuclear positivity in scattered foci that appeared to correlate with areas of regeneration. A biopsy from a single case of neurogenic atrophy secondary to infantile spinal muscular atrophy (Werdnig-Hoffmann's disease) demonstrated diffuse but relatively weak staining of myofiber nuclei, in contrast to sections of normal striated muscle and muscle biopsies from patients with unexplained myoglobinuria, which exhibited only minimal amounts of staining. These data are compatible with observations that MyoD1 expression is related to electrical activity and muscle regeneration.
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  • 47
    ISSN: 1432-0533
    Keywords: Inclusion body disease ; Electron microscopy ; Immunohistochemistry ; Viral infection ; Primary metabolic disorder
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A Caucasian female who was noted to be mildly microcephalic at birth was diagnosed as having cerebral palsy at the age of 1 year. Her development was delayed and she never walked or talked. She appeared relatively stable neurologically until the age of 17 years when she had an illness with fever thought to be due to a virus. She was noted to deteriorate from this time on until her death at the age of 19 years. Autopsy revealed intranuclear and cytoplasmic inclusions widespread throughout the brain and visceral organs. There was no evidence of inflammation. Immunohistochemistry revealed strong immunoreactivity for tau protein and neurofilament protein. Electron microscopy revealed the inclusions to be composed of homogeneous finely granular material. Scattered with the granular material in the cytoplasmic bodies were crystalline structures with a honeycomb appearance. The possibility of these changes representing an old viral infection or a primary metabolic disorder are discussed.
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  • 48
    ISSN: 1432-0533
    Keywords: Perineurial cells ; Nerve regeneration ; Immunohistochemistry ; Epithelial membrane antigen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Perineurial cells are specialized connective tissue cells that form a barrier between endoneurium and epineurium in normal nerves. In the present study, the formation of the perineurium after transection of rat sciatic nerves was investigated. The cord bridging the gap between proximal and distal stumps through silicone tubes was studied 3, 7, 12, 18, and 21 days after surgery using electron microscopy and antibodies against epithelial membrane antigen (EMA), a marker for perineurial cells that has thus far not been applied to the study of differentiating cells in nerve tubulation systems. Initially, a thin cord consisting of fibrin bridged the gap between the stumps. At 7 days, longitudinal cells had migrated from both stumps toward the center of the tubes on the surface of the fibrin cord. These cells were immunoreactive with anti-EMA. At 12 days, ultrastructural features of perineurial cells (desmosomes, tight junctions, actin filaments with dense bodies, tonofilaments) were prominent in these cells. Subsequently, the gap was bridged through the perineurial tube by endothelial cells, pericytes, fibroblasts, Schwann cells, and axons. At 21 days, a single large nerve fascicle ensheathed by a mature perineurium was found between the stumps. Thus, the first cells to connect proximal and distal stumps in the investigated nerve regeneration silicon chamber system are perineurial cells. Through the tube formed by these cells, blood vessels and nerve fibers bridge the gap. Therefore, establishment of a perineurial connection between nerve stumps appears to be important in the sequence of events during nerve regeneration.
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  • 49
    ISSN: 1432-0533
    Keywords: Round granulated body ; Eosinophilic hyaline droplets ; Astrocytic tumors ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Round granulated body (RGB) and eosinophilic hyaline droplets (EHDs) have been described as cytoplasmic inclusions of certain astrocytic tumors. In the previous literature, however, these inclusions have been described using various terms or regarded as nosologically the same entity. Light microscopically, RGB apeared as a round discrete body filled with fine uniform granules, while EHDs demonstrated a cluster of bright eosinophilic, round objects of various size. They could be clearly distinguished even by conventional histochemical staining such as the Masson trichrome stain and the phosphotungstic acid hematoxylin preparation. Both RGB and EHDs expressed positive immunoreactions for glial fibrillary acidic protein, several lysosomal markers, and some stress-response proteins. The ultrastructural appearances of these inclusions were distinct, however, one common feature was that they consisted of aggregations of numerous membrane-bound electron-dense bodies. Thus, both inclusions appear to be produced by neoplastic astrocytes and are possibly related to the lysosomal system. We examined the presence of RGB and EHDs in 138 astrocytic tumors. Both inclusions occurred most frequently in pleomorphic xanthoastrocytomas, followed by gangliogliomas and pilocytic astrocytomas. Subependymal giant cell astrocytomas exhibited only RGBs. RGBs and EHDs were not seen in any abundance in glioblastomas, gliosarcomas, fibrillary astrocytomas, protoplasmic astrocytomas, or oligo-astrocytomas. Some glioblastomas, however, showed only EHDs in small numbers. Several anaplastic astrocytomas were associated with a large number of RGBs and/or EHDs, and they revealed only rare mitosis despite marked cellular pleomorphism. Although RGB and EHDs have different morphological features, the presence of these inclusions in abundance may represent either a degenerative change, a long-standing lesion, or an indolent growth of the astrocytic tumors.
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  • 50
    ISSN: 1432-0533
    Keywords: Key words Amyloid angiopathy ; Enzymehistochemistry ; Hereditary cerebral hemorrhage with amyloidosis (Dutch) ; Immunohistochemistry ; Senile plaques
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Plaque-like lesions and amyloid angiopathy were investigated in the frontal cerebral cortex of four patients with hereditary cerebral hemorrhage with amyloidosis (Dutch) (HCHWA-D), using immunohistochemical [antibodies to β amyloid protein (Aβ), β protein precursor (βPP), synaptophysin, ubiquitin (UBQ), cathepsin D, paired helical filaments (PHF) and glial fibrillary acidic protein (GFAP)], enzymehistochemical (acid phosphatase) and silver [methenamine silver (MS) and Palmgren] staining methods. Whereas Aβ- and MS-positive diffuse plaques were found in all patients, only the three older patients showed neuritic or congophilic plaques, which were acid phosphatase and cathepsin D positive and contained βPP-, synaptophysin- and UBQ-positive, but PHF-negative neurites. These plaques were surrounded by reactive astrocytes. Similar immuno- and enzymereactivity was found around congophilic blood vessels. Thus, apart from neuronal degeneration in a subset of plaque-like lesions and around blood vessels, this study shows an age-related morphology of the plaques in HCHWA-D, corresponding to that in Down's syndrome (DS), with the difference that neurofibrillary (NF) pathology is absent in HCHWA-D in contrast to DS. HCHWA-D may be considered as a model for congophilic plaque formation not associated with NF pathology.
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  • 51
    ISSN: 1432-0533
    Keywords: Amyloid angiopathy ; Enzymehistochemistry ; Hereditary cerebral hemorrhage with amyloidosis (Dutch) ; Immunohistochemistry ; Senile plaques
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Plaque-like lesions and amyloid angiopathy were investigated in the frontal cerebral cortex of four patients with hereditary cerebral hemorrhage with amyloidosis (Dutch) (HCHWA-D), using immunohistochemical [antibodies to β amyloid protein (Aβ), β protein precursor (βPP), synaptophysin, ubiquitin (UBQ), cathepsin D, paired helical filaments (PHF) and glial fibrillary acidic protein (GFAP)], enzymehistochemical (acid phosphatase) and silver [methenamine silver (MS) and Palmgren] staining methods. Whereas Aβ-and MS-positive diffuse plaques were found in all patients, only the three older patients showed neuritic or congophilic plaques, which were acid phosphatase and cathepsin D positive and contained βPP-, synaptophysin-and UBQ-positive, but PHF-negative neurites. These plaques were surrounded by reactive astrocytes. Similar immuno-and enzymereactivity was found around congophilic blood vessels. Thus, apart from neuronal degeneration in a subset of plaque-like lesions and around blood vessels, this study shows an age-related morphology of the plaques in HCHWA-D, corresponding to that in Down's syndrome (DS), with the difference that neurofibrillary (NF) pathology is absent in HCHWA-D in contrast to DS. HCHWA-D may be considered as a model for congophilic plaque formation not associated with NF pathology.
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  • 52
    ISSN: 1432-0568
    Keywords: Cerebellum ; Neurological mutant ; Ganglioside ; Immunohistochemistry ; Neuron migration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The cerebellum is organized into a series of parasagittally aligned bands that may be revealed histologically in the adult mouse by largely complementary immunostaining of Purkinje cell sets with the monoclonal antibodies Zebrin II (ZII; antigen:aldolase C) and P-path (PP; antigen:90-acetyl glycolipids). We compared the normal staining pattern using these markers and an antibody to calbindin with that found in the reeler mutants (rl/rl), in which most Purkinje cell migration is halted beneath the cerebellar white matter. The results revealed that Purkinje cells in reeler mutants, despite their ectopic location in large subcortical masses, show a clear tendency to distribute into alternating zones that either stain for Zebrin II or for P-path, with variable transition zones of mixed labeling. However, the estimated number of zones was fewer than in the normal adult cortex: roughly 7–9 zones are revealed per side in the mutant compared with 14 major divisions in wild type mice. These results raise the possibility that neurons destined to express these markers are segregated during their migration and that the final phase of migration into the cortex might involve further splitting or interdigitation between cell sets expressing the two antigens.
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  • 53
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    Anatomy and embryology 190 (1994), S. 251-261 
    ISSN: 1432-0568
    Keywords: C-CAM ; Immunohistochemistry ; In situ hybridization ; Palate formation ; Retinoic acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract C-CAM is a cell surface glycoprotein that is involved in cell adhesion and may play a role in histogenesis and organogenesis. It is a member of the carcinoembryonic antigen (CEA) gene family, which is a subfamily of the immunoglobulin gene superfamily. We have analyzed the expression of C-CAM during normal and disturbed craniofacial development in the mouse by immunohistochemistry and in situ hybridization. Developmental disturbances were induced by retinoic acid (RA) treatment of pregnant mice. Normal and malformed fetuses were examined on days 14, 15, 16, 17 and 18 of gestation. The expression of C-CAM was detected first at day 16. With age, the signal became gradually stronger. C-CAM was detected in the epithelia of both ectodermal and mesodermal origin, including oral and respiratory epithelia, epithelia of the developing vessels, glands and their ducts. In the RA-treated fetuses, the expression of C-CAM was higher in the epithelium of the oral cavity than in that of the nasal cavity, with a distinct borderline between differentiating nasal and oral epithelium of the palatal shelves. However, the submucosal nasal glands and ducts showed higher expression than oral glands in both normal and RA-treated mice. The expression of C-CAM did not differ significantly between control and RA-treated animals. The presence of C-CAM in all proliferating craniofacial epithelia indicates that this molecule may play an important role in development.
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  • 54
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1715-1721 
    ISSN: 0392-6737
    Keywords: Fluctuations (noise, chaos, nonequilibrium superconductivity, localization, etc.) ; Flux pinning ; flux motion ; fluxon-defect interactions ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary High-quality single-phase thin platelets of BSCCO-2223 have been produced by a novel method on thermal-gradient-enhanced KCl flux which allows the growth of the 2223-phase in an extremely short time interval compared to those reported in the literature. In-plane electrical resistivity measurements in zero applied magnetic field have been performed. Experimental data have been analysed and interpreted within the Aslamazov-Larkin theory of amplitude fluctuations and the Ginzburg-Landau Coulomb gas model of phase fluctuations. These theories seem to fit in a very reliable way the experimentalR(T) curves.
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  • 55
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1815-1820 
    ISSN: 0392-6737
    Keywords: Insulator-superconductor transitions ; unconventional mechanisms of high-T c superconductivity ; Other topics in superconductivity ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary The temperature dependence of local Cu site conformations in single-domain crystals of Bi2Sr2CaCu2O8+y (Bi-2212) and La1.85Sr0.15CuO4 (La-214) has been determined by EXAFS (Extended X-ray Absorption Fine Structure), a fast (10−15 s) and local probe. Two sets of Cu site conformations characterized by the Cu−O(apical) bond distances and tilting of copper square plane have been found atT〈T*∼1.5T c . The difference between the long and short Cu−O(apical) distance appeared to be 0.17 Å and 0.12 Å atT〈T* in Bi-2212 and La-214 systems, respectively. The polarons are associated with the short Cu−O(apical) bond distance. The ratio between the number of short and the total number of Cu−O(apical) bonds (N short/N tot∼0.42 in both systems) is a measure of the relative area of distorted and undistorted domains. By using this result we have been able to show the polaronic nature of the one-dimensional structural anharmonic modulation of the CuO2 plane in Bi-2212 where the polarons have dimensionW=(11±1) Å atT〈T*≈1.4T c and are condensed into a one-dimensional generalized Wigner charge density wave (CDW). It appears that superconductivity is stabilized at thigh temperature by resonant quantum confinement in a superlattice of stripe widthL wherek Fx ∼k Fy ∼π/L.
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  • 56
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1843-1849 
    ISSN: 0392-6737
    Keywords: Fluctuations (noise, chaos, nonequilibrium superconductivity, localization, etc.) ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary This work is focused on how oxygen stoichiometry and distribution affects the pretransitional region in YBa2Cu3O7−δ pellets prepared by different thermal treatments starting from the same batch with oxygen content 6.94. We find that slightly deoxygenated samples, which show higherT c and narrower transition than the starting material, also exhibit a more pronounced rounding of the resistivity extending towards higher temperatures. We analyse the presence and the extension of regions with different power law behaviour of excess conductivityvs. temperature.
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  • 57
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1871-1876 
    ISSN: 0392-6737
    Keywords: Magnetization curves ; Meissner effect ; penetration depth ; Critical currents ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary BSCCO (2223) phase superconductor, prepared by the traditional solid-state reaction route, was densified by hot pressing, yielding high-density and textured-bulk materials. A correlation between processing parameters and inter-, intra-granular properties of the sample was performed through the evaluation of microstructural features and the study of electrical resistivity and magnetization behaviour as a function of different temperature and magnetic field.
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  • 58
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1925-1932 
    ISSN: 0392-6737
    Keywords: Flux pinning ; flux motion ; fluxon-defect interactions ; Critical currents ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary The results of low-temperature magnetic-relaxation experiments in TlBaCaCuO superconductors (2212 and 2223 phase) are reported. They give evidence of a crossover from a thermally activated regime of flux motion to a nonthermally activated one. The magnetic-relaxation rate is found to become temperature independent below ≅7K and ≅3K, for the 2212 and 2223 phase, respectively. Its value compares well with that predicted by the theories of flux motion by quantum tunnelling.
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  • 59
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1917-1924 
    ISSN: 0392-6737
    Keywords: Flux pinning ; flux motion ; fluxon-defect interactions ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Measurements of fundamental and higher harmonics of a.c. susceptibility on polycrystalline high-T c superconductors were carried out using a new method, involving a 2-channel dynamic analyser, allowing 20 harmonics in phase and out of phase to be measured at the same time. The critical-state model, used for describing the higher-harmonics dependence on temperature at fixed d.c. and a.c. magnetic fields, did not explain the experimental results. A frequency analysis indeed suggested that an effect of the fluxon dynamics takes place. Simple considerations lead to the conclusion that really Thermally Activated Flux Flow (TAFF), Flux Creep (FC) and Flux Flow (FF) would have a big role in determining the higher harmonics of a.c. susceptibility. Measurements on low-T c superconductors showed the occurrence of the same effect.
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  • 60
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1933-1939 
    ISSN: 0392-6737
    Keywords: Flux pinning, flux creep, and flux-line lattice dynamics ; Critical currents ; Material effects onT c, κ, critical currents (including impurities, ion implantation, etc.) ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Bulk slabs of sintered YBCO were irradiated with monoenergetic protons at different energies (3.5 and 6.5 MeV) and different fluences, ranging from 1.8·1016 to 8.6·1016 p/cm2. The effects on intergrain critical currents of protons crossing the sample and the effects of protons implanting in the specimen, has been studied by means of a.c. susceptibility characterizations. D.c. hysteresis cycles were measured in low fields in order to investigate the modifications in the intergrain critical current density due to proton implantation. The main result is the evidence that the intergrainJ c response to the applied field can be modulated by means of the proton irradiation. Resistive measurements were also performed in order to investigate the complex transport phenomena in polycrystalline materials. Irradiation-induced effects on both superconducting- and normal-state resistivity are studied. The addition of extrinsic defects can lead to enhanced transport properties, emerging especially when a magnetic field is applied.
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  • 61
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1671-1678 
    ISSN: 0392-6737
    Keywords: Effects of material synthesis ; crystal structure ; chemical composition ; Y-based compounds ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary YBCO with high granulometric perfection and low dispersion can be obtained by a low-temperature reaction (≈800°C) of atomic-scale dispersed powders, produced through the thermal decomposition of liquid precursors. As reacted such powders are tetragonal and not superconducting, but they transform into the high-T c phase after optimized annealing treatments. We describe the method we developed and the characteristics of the materials we achieved, and we discuss the main features of the process in the light of the current know-how.
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  • 62
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 2019-2024 
    ISSN: 0392-6737
    Keywords: Proximity effects, tunneling phenomena, and Josephson effects ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary An analysis of superconducting transport properties and magnetic behaviour of d.c. SQUIDs employing YBCO bicrystal grain boundary junctions (GBJs) has been performed. GBJs have been obtained by deposition of ac-axis-oriented YBCO film on a SrTiO3 bicrystal substrate by ICM sputtering technique. Experimental measurements on a YBCO d.c. SQUID with a misorientation angle θ=20° are reported. The SQUID shows a critical temperatureT c∼89 K and a high critical current densityJ c∼3·106 A/cm2 atT=4.2 K. Current-voltage characteristics are close to the behaviour predicted by the resistively shunted junction (RSJ) model and the temperature dependenceJ c(T) shows a linear behaviour at small reduced temperatures and a depressedJ c value close toT c. High-quality flux-voltage curves have been found upT=87 K over a large range of magnetic field. The high reproducibility and the good control of transport properties by the variation of θ make YBCO bicrystal GBJs very useful for applications in electronics.
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  • 63
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1799-1802 
    ISSN: 0392-6737
    Keywords: Relaxation effects ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary High-temperature (T〉200 K)139La NMR relaxation rates in single crystals of La2CuO4+δ (δ∼0.015 and δ∼0.002) at two measuring frequencies are presented and compared with zero-field NQR data for a series of La2−x Sr x CuO4+δ powder samples with 0≤x≤0.08 and 0〈δ0.013. For δ≠0 an enhancement of the relaxation rate is observed which is related to the time dependence of the quadrupole interaction. Quantitative information on the oxygen diffusion is obtained from the analysis of the data with a simple diffusion model. The results are discussed in relation to the problem of macroscopic phase separation occurring for higher oxygen content.
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  • 64
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1701-1708 
    ISSN: 0392-6737
    Keywords: Superconducting perovskites and related structures ; Treatment of materials and its effects on microstructure and properties ; Conductivity phenomena in semiconductors and insulators ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary The transformation of the 2223 (n=3) phase in the 2201 (n=1) phase by heating the sample in Ar atmosphere was studied. The subsequent cycling of the sample temperature and the oxygen enrichment of the gas phase convert the 2201 (n=1) phase in the 2223 (n=3) phase in the presence of the 2212 (n=2) and Ca2PbO4 compound. Thein situ resistivity measurements,T c values and XRD carried out on the sample confirm these phase changes. The experiment indicates that this process is oxygen dependent at low oxygen partial pressure.
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  • 65
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1735-1741 
    ISSN: 0392-6737
    Keywords: Response to electromagnetic fields ; nuclear magnetic resonance ; ultrasonic attenuation ; Scattering by phonons, magnons, and other nonlocalized excitations ; Superconducting perovskites and related structures ; Refractive index, reflectivity, critical angle, dispersive power ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Evidence of polaron formation in superconducting cuprates is provided by infrared reflectivity spectra. In the Nd−Ce−Cu−O withT c≈20 K, polaron formation corresponds to vibrational local modes in the far-infrared and to a band in the mid-infrared built up through overtones and combination bands of these modes. A comparison with infrared spectra taken by different groups on Y−Ba−Cu−O, and Tl−Sr−Ca−Cu−O suggests that polarons survive in the highest-T c superconductors.
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  • 66
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 2005-2010 
    ISSN: 0392-6737
    Keywords: Superconducting films ; PACS 81.15.Cd ; Deposition by sputtering ; Microwave circuits (e.g., parametric, solid state) ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Superconducting films of YBa2Cu3O7−x were depositedin situ on LaAlO3 substrates using single-target 90° off-axis sputtering. The obtained films have tipicalT c values of 91K. Surface resistance measurements on as-grown films reach 1.1 mΩ at 77K and 10GHz; whilst on ion-etched patterned resonant linesR s (77K, 10GHz) it is about 10mΩ.
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  • 67
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 2113-2117 
    ISSN: 0392-6737
    Keywords: Superconducting magnets and magnetic levitation devices ; superconducting cables and conductors ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Ag/BSCCO-2223 phase tapes were prepared with a new plastic deformation cycle. Starting from the hot extrusion of composite billets, hundreds of metres of tape 0.15×3 mm were obtained by drawing and rolling the extruded bars. The cross-section, monofilamentary with a central Ag insert, is quite regular along all the length. Samples from 30 cm to 100 cm in length were heat-treated at different temperatures between 830°C and 480°C in Ar+10% O2 atmosphere. Electrical-transport properties were tested at 77K.J c of 3000 A/cm2 were usually achieved after first heat treatment. The superconducting properties were also tested by magnetic measurements using a vibrating sample magnetometer.
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  • 68
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    Keywords: Polymer reactions and polymerization ; Brillouin and Rayleigh scattering ; Conference proceedings
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    Topics: Physics
    Notes: Summary We analyse data from the dynamic light scattering of poly(N-isopropylacrilamide) in water solution as we cross the collapse transition. Experimental data are interpreted by the Gaussian self-consistent Zimm model that takes into account two- and three-body excluded-volume effects, and Oseen hydrodynamic interactions, as well as by the standard cumulant and Contin analyses. By fitting the dynamic structure factor we extract the temperature dependence of the diffusion coefficientD and the first relaxation time τ1 across the collapse transition for a range of scattering angles. The relaxation time τ1 possesses a characteristic peak at about 32.4 °C due to slowing of the internal motions of the polymer at the theta-point, and a minimum at 33.4 °C. We interpret this as a combination of collapse closely followed by the growth of critical correlations. At large scattering angles we reach the universalk 3 regime, and observe that this behaviour vanishes at the onset of collapse transition.
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  • 69
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 817-824 
    ISSN: 0392-6737
    Keywords: Computer simulation of static and dynamic behavior ; Liquid metals and liquid alloys ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Results of extensive computer simulations performed in liquid water are reported in order to clarify the main features of dynamical density correlations in this system. Puzzling aspects, such as the anomalous sound wave propagation at finite wave vectors, are related to the peculiar structural aspects of this hydrogen-bonded liquid. Additional features (such as the evolution of the relevant memory functions at increasing wave vectors and the emergency of a second mode in the longitudinal current spectra) are also discussed in some detail.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 697-702 
    ISSN: 0392-6737
    Keywords: Polymers, elastomers, and plastics ; Field theory ; Spontaneous and radiative symmetry breaking ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Filamentary-surfaces randomly branched polymers can be represented byO(N) symmetric quantum field theories in the limit whereN→∞ and the coupling constantg→g c in a correlated manner. The statistical systems of randomly branched polymers are realized as dual diagrams of the Feynman graphs of the underlyingO(N) symmetric quantum field theory. The purpose of these studies is to gain intuition for the long-lasting search for a possible description of quantum field theory in terms of extended objects.
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  • 71
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 803-807 
    ISSN: 0392-6737
    Keywords: Conformation (statistics and dynamics) ; Polymers and plastics ; Heterogeneous liquids: suspensions, dispersions, emulsions, pastes, slurries, foams, block copolymers, etc ; Thermodynamics of surfaces and interfaces ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Simulation results as well as experimental data indicate that full stretching of flexible polyelectrolytes will not occur under experimentally realizable conditions. Using density-dependent swelling exponents ν(ϕ) as suggested by Stevens and Kremer from the results of a MD simulation study, we present an Alexander-de Gennes-like scaling picture for the behaviour of charged brushes. The brush height is found to become dependent on the grafting density as soon as internal stretching is incomplete. For a particular anchoring technique used in experimental studies the grafting density itself becomes dependent on the chain length. The resulting modified overall chain length dependence of the brush height is discussed.
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  • 72
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 835-842 
    ISSN: 0392-6737
    Keywords: Order-disorder and statistical mechanics of model systems ; Small-angle scattering, EDXD, EXAFS, and other techniques ; Layer structures, intercalation compounds, and superlattices: growth, structure, and nonelectronic properties ; Polymers, elastomers, and plastic ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary A homologous series of nine symmetric poly(styrene)-block-poly(butadieme) diblock copolymers was synthesized and characterized. The scaling of the lamellar thickness,D, with the chain lengthN(DαN δ ) was investigated with small-angle X-ray scattering. Different sample preparation methods were used: annealing, solvent-casting and shear alignment. We find that the lamellar thickness and thus the value of the exponent δ depends on the preparation method used,i.e. care must be taken to ensure that the samples investigated are in thermodynamic equilibrium.
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  • 73
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 865-871 
    ISSN: 0392-6737
    Keywords: Disperse systems ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary The phase diagram of the ternary system,i.e. poly(diallyldimethylammonium chloride), poly(acrylic acid, sodium salt), and water was investigated by varying the molecular weight of the components. In general, a range of phase separation is surrounded by a one-phase system. The range of phase separation can be subdivided into a region of flocculation and/or coacervation in contrast to stable symplex dispersions. By increasing the molecular weight of the components the range of phase separation is increased and phenomena of flocculation followed by coacervation were observed predominantly. Above a molecular weight of 10 000 g/mol the transition to concentrated macroscopic homogeneous one-phase systems was observed at a constant ionic strength of 2 mol/l coinciding with the «critical ionic strength» for Coulombic interactions in this system. That means the transition to concentrated one-phase systems can be understood by the disappearance of Coulombic forces above a system-specific ionic strength resulting in a quite additive behaviour of the mixtures with regard to the components.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 895-900 
    ISSN: 0392-6737
    Keywords: Liquid crystals ; Interface elasticity, viscosity, and viscoelasticity ; ther topics in the structure and nonelectronic properties of surfaces and thin films ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary The nematic planar anchoring is usually explained by using simple elastic models: the surface easy axis corresponds to the surface direction that minimizes the excess of nematic elastic energy. When anisotropic rough substrates are used to align nematic liquid crystals, due to the complex surface morphology, usual elastic models are not directly applicable. This paper presents quantitative topographical data of rough substrates, obtained with oblique SiO evaporation under vacuum for nematic planar anchoring. Experimental data are obtained by means of Atomic Force Microscopy and they are used to demonstrate the self-affine nature of these substrates and to relate the nematic anchoring with the anisotropy of the local fractal properties of the substrate itself.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 637-640 
    ISSN: 0392-6737
    Keywords: Polymers, elastomers, and plastics ; Interface elasticity, viscosity and viscoelasticity ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary We discuss the role of «connectors» between two rubber blocks or between a rubber and a solid. Early descriptions of these systems were restricted to very dilute connectors, working independently. In the present work, we investigate theoretically the role and the limits of the surface concentration of connectors.
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  • 76
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 923-931 
    ISSN: 0392-6737
    Keywords: Brillouin and Rayleigh scattering ; Ultrasonic relaxation processes in gases, liquids, and solids ; Structure of associated liquids ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary We have performed Brillouin and depolarized Rayleigh light scattering on water-methanol solutions as a function of methanol molar fraction and temperature. For this system, molecular-dynamics (MD) simulation predicts that a shell of water forms around a methanol molecule, prediction which has been recently confirmed by neutron diffraction experiments. The results obtained by light scattering and presented here confirm previous observations and show, in addition, an increase of the stability in time of the water structure in the shells when temperature decreases and methanol concentration approaches a particular value.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 641-652 
    ISSN: 0392-6737
    Keywords: Macromolecular and polymer solutions (solubility, swelling, etc.) ; polymer melts ; Thermodynamics of surfaces and interfaces ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary We consider the configurations and the various regimes when an alternating, symmetric, multiblock copolymer made of successive sequences of A and B monomers with equal lengthZ is at the interface between two immiscible solvents that are respectively good for one of the sequences and poor for the other one. We find two semi-dilute regimes, when the copolymers overlap. For monomer concentrations belowГ **, we find a first range where the thickness of the copolymers is constant and equal to the radius of a sequence. For concentrations larger thanГ **, a second regime appears, where the seqeunces stretch our and adopt a conformation similar to what was reported for grafted polymers. Finally at a concentrationГ sat, the interface is completely saturated, and the copolymers form micelles in the bulk: it becomes energetically more favourable to have copolymers in the bulk than at interface.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1205-1216 
    ISSN: 0392-6737
    Keywords: Statistical theories of liquid structure ; Computer simulation of static and dynamic behavior ; General studies of phase transitions ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Binary-fluid mixtures show first-order phase transition phenomena which are either classified as mixing-demixing (phase separation), or as condensation-evaporation. The localization of the transition lines, the characterization of the new phases, and the analysis of the parameters which force model systems to choose one of the two transition mechanisms is the aim of this study. We performed both parallel-molecular-dynamics simulations and integral-equation theory calculations on binary mixtures of Lennard-Jones particles. By fixing the composition and by varying the interaction strength, we found a continuous change between the two kinds of transition mechanisms. Theoretical and simulation results are compared with each other and a quantitative agreement i8s found. However, the simultation analysis appears to be more promising since, in contrast to the integral-equation theory in which the spinodal lines can only be approched, information on the microscopic structure of the new phases can be obtained.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1065-1089 
    ISSN: 0392-6737
    Keywords: Optical chaos ; Classical mechanics of continuous media: general methematical aspects ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary In 1952 A. Turing introduced the concept of chemical morphogenesis. A medium with at least two interacting and diffusing components (activator and inhibitor) can be subjected to spontaneous pattern formation, with a scale length independent of the boundary conditions, and thus maintained even in the infinite volume limit. This is at variance with pattern formation in fluids (as,e.g., Rayleigh-Benard and Faraday instabilities) where the size is imposed by the boundary geometry. In non-linear optics, patterns emerge from the coupling of a diffractive equation describing electromagnetic propagation with a diffusion equation describing the local modification of the polarizability in a medium. As we adjust an extensive parameter (the so-called Fresnel numberF) corresponding to the optical aspect ratio, we observe a transition from a regime dominated by the boundary constraints to a Turing-type regime dominated by the bulk parameter. This is equivalent to saying that the preminent role is due to the diffractive equation in one case and to the diffusive one in the other. Morphogenesis for lowF arises from the non-linear competition among a small number of degrees of freedom, giving rise to a space-uniform excitation with a low-dimensional dynamics. This gives rise to the different scenarios of chaos. Their properties have been explored in the past decade. In the large-F case, the space-time instabilities rapidly evolve toward complex patterns, not reducible to a few indicators. In the case of two-dimensional fields, global characterization is achieved via the statistics of the topological defects.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1127-1139 
    ISSN: 0392-6737
    Keywords: Colloids ; Solubility, segregation, and mixing ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary We review the phase behaviour of mixtures of colloids and non-adsorbing polymers. The exclusion of polymer molecules from overlapping «depletion zones» between two neighbouring colloidal particles results in an unbalanced osmotic pressure pushing the particles together. This depletion potential is separately tunable in range and depth. Theory predicts that the resulting phase behaviour is sensitive to ξ=r g/R, the ratio of the radius of gyration of a polymer molecule, to the radius of the colloid. At large ξ, a stable colloidalliquid phase becomes possible. This has been confirmed by recent experiments. The formation of non-equilibrium «transient gel» states when the size ratio is small (≈0.08) is also introduced briefly.
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  • 81
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1171-1176 
    ISSN: 0392-6737
    Keywords: Thermal expansion and thermomechanical effects ; Lattice theory and statistic ; Ising problems ; Polymer reactions and polymerization ; General studies of phase transitions ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary The role of chemical reactions in the selection of patterns in phase-separating mixtures is presented. Linearized theory and computer simulation show that the initial long-wavelength instability characteristic of spinodal decomposition is suppressed by chemical reactions, which restrict domain growth to intermediate length scales even in the late stages of phase separation. Our findings suggest that chemical reactions may provide a novel way to stabilize and tune the steady-state morphology of phase-separating materials.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1373-1390 
    ISSN: 0392-6737
    Keywords: Mechanical properties of liquids ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary A general method is presented for the preparation of viscoelastic surfactant phases that consist of densely packed multilamellar vesicles in water. The phases form spontaneously when ionic surfactants are added to Lα-or L3-phases from uncharged surfactants and cosurfactants. The dimensions and the structure of the vesicles were studied from FF-TEM micrographs for 100 mM surfactant solutions. The average diameter of the vesicles is in the range of 1 μm, the interlamellar spacing is around 800 Å. Under these conditions the vesicles are densely packed and cannot pass each other. The systems are highly viscoelastic and have a yield value. The storage and the loss moduli were determined by oscillating rheological measurements. The storage modulus was about one order of magnitude larger than the loss modulus and independent of frequency. Both parameters were determined as a function of the concentration and the chain length of the surfactant and cosurfactant, the charge density and ionic strength, the solubilization of hydrocarbon and temperature. The yield values and shear moduli increase linearly with the surfactant concentration. For constant surfactant concentration the moduli increase in a S-shaped form with the charge density and reach saturation for a mole fraction of about 7% of ionic surfactant. The storage moduli and yield values decrease with the addition of excess salt. The storage moduli depend strongly on the chain length of the surfactant. The values of the moduli are explained on the basis of a hard-sphere model in which the multilamellar vesicles are considered as hard-sphere particles.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1433-1437 
    ISSN: 0392-6737
    Keywords: Viscosity and diffusion: experimental ; Diffusion and thermal diffusion ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary The dynamics of water molecules occupying very small volumes can be probed by incoherent quasi-elastic neutron scattering. We summarise some results obtained with wet samples of porous silica and hydrated proteins. The movements of the molecules in the vicinity of the substrate are extremely reduced as compared to those of bulk water at the same temperature. Almost only rotational movements subsist and the local diffusion is of the order of that observed in deeply supercooled water.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1471-1477 
    ISSN: 0392-6737
    Keywords: Photochemical reactions of biomolecules biochemical reaction mechanisms and kinetics, model reactions ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Photoinduced electron transfer (PET) was studied in phospholipid vesicles and in Langmuir-Blodgett bilayers in the attempt to produce a model for electron transfer processes in biological media. Spatial organization of the reaction centers in lipid membranes needs to be controlled in order to provide high efficiency of light-to-chemical energy conversion. We designed a phospholipid system where the donor is localized in the inner bilayer whereas the acceptor is at the polar groups-water interface. We used dipalmitoylphosphatidic acid vesicles containing low molar fractions of dipalmitoylphosphatidylcholine with pyrene (donor) bound to one of the alkyl chains. Methylviologen (acceptor) was added to the external aqueous phase; upon photoexcitation of the donor we observed the electron transfer to take place in a unidirectional manner from the inside of the bilayer to the interface. Information about the location of the donor was obtained studying the photophysical properties of the pyrene chromophore in vesicles and in LB layers. The photoinduced electron transfer reaction was evidenced by quenching of pyrene fluorescence in the presence of increasing concentrations of acceptor, the process was studied both with steady-state and time-resolved fluorescence emission. Fluorescence intensity was found to decrease with increasing concentration of methylviologen, similar results were obtained for vesicles and LB layers of analog composition immersed in a methylviologen solution. Lifetimes of the excited species were found to be of the same order of magnitude in vesicle and LB-layer systems.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1297-1303 
    ISSN: 0392-6737
    Keywords: Fluid surfaces and fluid-fluid interfaces ; Liquid thin films ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Stiff rod-like chain molecules with harmonic bond length potentials and trigonometric bond angle potentials are used to model Langmuir monolayers at high densities. One end of the rod-like molecules is strongly bound to a flat two-dimensional substrate which represents the air-water interface. A ground-state analysis is performed which suggests phase transitions between phases with and without collective uniform tilt. Large-scale off-lattice Monte Carlo simulations over a wide temperature range show in addition to the tilting transition the presence of a strongly constrained melting transition at high temperatures. The latter transition appears to be related to two-dimensional melting of the head group lattice. These findings show that the model contains both, two- and three-dimensional ergodicity breaking solidification transitions. We discuss our findings with respect to experiment.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1401-1410 
    ISSN: 0392-6737
    Keywords: Mechanical properties of liquids ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Both linear and non-linear viscoelasticity experiments have been performed in semi-dilute micellar aqueous solutions of ethanediyl-α,ω-bis (dodecylmethylammonium bromide) as a function of solution chloride (NaCl) concentration. The results suggest that both linear and non-linear properties are affected by the electrostatic interactions. In particular, the plateau modulusG′∞ and the ratioσ m/G′∞, whereσ m represents the plateau value in a stress-shear rate experiment, are enhanced as the electrostatic interactions are screened by addition of salt. The zero-shear viscosity is lowered upon addition of NaCl, due likely to an exchange of the Cl− ions with the Br− counterions.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1367-1372 
    ISSN: 0392-6737
    Keywords: Fluid surfaces and fluid-fluid interfaces ; Transitions in liquid crystals ; Defects in liquid crystals ; Liquid thin films ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Optical studies of Langmuir monolayers of simple amphiphiles such as fatty acids and esters by polarized fluorescence microscopy and Brewster-angle microscopy reveal a large variety of textures including stripes, stars, and spirals that closely resemble textures observed in liquid crystals. The textures represent large-scale (〉10 μm) spontaneous organization of the molecular tilt azimuth. Phase transitions within the monolayer can be directly observed by marked changes in texture, revealing a complex phase diagram. Many of the textures can be explained by a Landau-deGennes theory of tilted hexatic phases that takes into account the broken-symmetry characteristic of amphiphiles at an interface.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1411-1418 
    ISSN: 0392-6737
    Keywords: Physical chemistry of solutions of biological macromolecules ; Colloids ; Gels and sols ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Mucus is the viscoelastic secretion that lines, most epithelial surfaces forming a protective, lubricating barrier. The viscoelastic properties of mucus arise from mucin, a glycoprotein of molecular weight ranging from 2–10 million. In this paper we address two problems where the aggregation and interactions of mucin with colloidal particles is of physiological relevance. The first deals with gastric mucin and the question of the mechanisms that prevent the stomach from digesting itself. Using dynamic light scattering techniques we show that solutions of gastric mucin aggregate belowpH 4. Very large aggregates with 100-fold slower diffusion constants than the mucin monomer are observed atpH 2. Viscosity measurements indicate that mucin will eventually gel at lowpH, thus acting as a diffusional, barrier and protecting the stomach. The second problem is concerned with the role of mucin in the nucleation of cholesterol crystals which lead to gallstone formation. Using dynamic light scattering we have shown that mucin at relatively low concentrations (4 mg/ml) promotes the fusion of phospholipid + cholesterol vesicles. The time evolution of the fusion process was measured. No changes in the aggregation state of the gallbladder mucin were observed during the fusion process, suggesting that this phenomenon is related to physico-chemical interactions between the polymer (mucin) and the colloidal particle (vesicle).
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1551-1557 
    ISSN: 0392-6737
    Keywords: Disperse systems ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary A simple computer model of defection process caused by interactions between melittin and phosphatidylcholine (PC) model membrane has been proposed. It leads to a scaling formula which connects the average diameter (or linear size parameter) of the affected domain with the reciprocity of the number of such domains. Some preliminary investigations show the scaling exponent to be a small fractional number between ca. 0.3 and 0.1, depending on the number of possible infection directions and the type of lattice taken as a lipid matrix. Such small values of the scaling exponent can roughly be interpreted in terms of random tesselations on a plane (like random Voronoi networks), and the whole process displays a statistical self-similarity. The values obtained seem to be, however, small comparable to the scaling exponents characteristic for the faulting process occurring during the earthquake propagation.
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1579-1584 
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    Keywords: Fluid surfaces and fluid-fluid interfaces ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Oriented systems such as monolayers and Langmuir-Blodgett multilayers constitute supramolecular structures appropriate for ion detection. In fact, they are sensitive to small quantities of ions since they have specifically oriented ligand head groups that can easily combine with the ions to be detected in solution. We investigated monolayers of dioctadecyldithiocarbamate (DODTC) specificially synthesized and we studied the interactions of the monolayers with transition metal ions such as Ni2+ dissolved in the subphase. The spreading isotherms, the surface potential-area isotherms and the spectroscopic measurements (UV-Vis absorption and ESCA spectroscopy) show that the metal ions can combine with the DODTC monolayers. The present findings show that it is possible to employ these systems to build chemical sensors for transition metal ions
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  • 91
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1585-1594 
    ISSN: 0392-6737
    Keywords: Molecular biophysics ; Defects in liquid crystals ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary The effect of adding the defect-forming molecules melittin and C12E5 to DMPC membranes has been studied and the corresponding phase diagrams established. Light, X-ray and neutron small-angle scattering have been used to characterize the mixed membranes. Both systems show a melting of the lamellar Lα into an isotropic phase upon addition of the second membrane constituent. The molar ratio, where the melting occurs is the same in concentrated and dilute samples. For the DMPC/C12E5 system not only membrane composition, but also temperature can be used to induce a transition from an isotropic to a lamellar phase.
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  • 92
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1619-1625 
    ISSN: 0392-6737
    Keywords: Brillouin and Rayleigh scattering ; Ultrasonic relaxation processes in gases, liquids, and solids ; Acoustical properties of liquids ; Order-disorder and statistical mechanics of model systems ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary A water/butoxyethanol solution has been investigated by means of several techniques (viscosity, ultrasound and hypersound) as a function of concentration and temperature. The butoxyethanol molar fraction range investigated was situated between 0.015 and 0.09, while temperature ranged between −10°C and +45°C. We observed the building-up of large structures lowering the temperature, in particular below +15°C. All data coming from different techniques seem to confirm such a picture and indicate that this aggregation phenomenon is a percolation-like process.
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  • 93
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1679-1683 
    ISSN: 0392-6737
    Keywords: Thermodynamic properties ; thermal conductivity ; Methods of crystals growth and purification ; Phase diagrams of other materials ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary In this work the thermal conditions required for single-crystal growth in RBa2Cu3O7−x systems (R=Y or rare earths apart from Ce and Tb) have been systematically revised in order to improve the size of crystals obtainable by the flux method. Large single crystals of NdBCO, SmBCO and EuBCO have been actually obtained and characterized by XRD, oxygen content and electrical resistivity.
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  • 94
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1695-1699 
    ISSN: 0392-6737
    Keywords: Bi-based compounds ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary A systematic study of yttrium substitution for calcium in the high-temperature superconductor Bi2Sr2CaCu2O8 compound has been performed. The samples of Bi2Sr2Y x Ca1−x Cu2O8 have been prepared by the sintering standard procedure using oxides and carbonates as precursors, weighted to obtain the nominal composition with 0≤x≤1. The real stoichiometric composition of the pellets and uniformity of the samples has been verified by EDS analysis. The grain dimension (≈1 μm) and the good pellet compactness have been established by SEM morphologic observation. By X-ray diffraction analysis the crystalline structure of orthorhombic type has been established. By increasing the yttrium concentration the resistivity dependence on temperature goes from metallic to insulating behaviour. For the superconductive samplesT c decreases for increasing doping percentage. «Thick» films on MgO substrates of Bi2Sr2CaCu2O8 have been obtained by melting-quenching-annealing procedure. These films showed critical temperatures higher than the pellets.
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  • 95
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1723-1728 
    ISSN: 0392-6737
    Keywords: Superconducting materials ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Two procedures of partial melting of bulk NdBa2Cu3O7−δ, in air and in reduced oxygen pressure, were developed. When the treatment was carried out in air, poor superconducting properties were observed. On the contrary, when the treatment was carried inP O 2=1.3 mbar, good properties were obtained, withT conset=93 K and 100% shielding at lower temperatures. Near full density (2.5×2.5×28) mm3 Nd1.07Ba1.89Cu3.04O7−δ bars, with domains extending in the mm size range, were obtained.
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  • 96
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1755-1760 
    ISSN: 0392-6737
    Keywords: La-based compounds ; Tl-based compounds ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Deterioration of the superconducting properties of HTC materials, induced by different substitutions, offers a key towards the understanding of the basic HTC interactions. Similar effects are obtained either by doping of layers of the perovskite not directly involved in the superconducting mechanism, or by direct substitution of the copper itself. However, this apparent similarity is misleading. In YBCO, for instance, in the first case the oxygen content or the substitution of Y with Pr4+ appear to control essentially the carrier density,n, while in the second case the direct substitution of Cu in the bilayers by Zn or Ni affects more extensively the overall electronic structure of the material. A sensitive experimental tool, such as μSR, detects correspondingly different behaviours.
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  • 97
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 2039-2044 
    ISSN: 0392-6737
    Keywords: Proximity effects, tunneling phenomena, and Josephson effects ; Amorphous, highly disordered, and granular superconductors ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary We present a careful study of the behaviour of the below-gap photoresponse in 2D arrays of superconducting junctions. We have included the effects of the temperature, not only through the white-noise current term, but also through theT-dependence of the junction coupling energy. In order to render our model more realistic we also consider the correction due to the self-field generated by the screening currents.
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  • 98
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 2067-2072 
    ISSN: 0392-6737
    Keywords: Superconducting magnets and magnetic levitation devices ; superconducting cables and conductors ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary This paper reviews and assesses the progress in conductor development across the world in advancing high-temperature superconducting science and technology towards the fabrication of superconducting transmission cables operating at 77 K. Materials, fabrication routes and the feasibility of high-temperature superconducting cables will be discussed.
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  • 99
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 2095-2102 
    ISSN: 0392-6737
    Keywords: Proximity effects, tunneling phenomena, and Josephson effects ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary The current status of the electronic applications of high-T c Josephson junctions is briefly reviewed. Recent results obtained by the authors on devices employing step-edge junctions are reported. In particular the design of a microwave oscillator based on a parallel array of junctions is discussed and preliminary experimental results are presented.
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  • 100
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    Il nuovo cimento della Società Italiana di Fisica 16 (1994), S. 1941-1946 
    ISSN: 0392-6737
    Keywords: Superconducting materials ; General properties ; Critical currents ; Material effects onT c,x, critical currents (including impurities, ion implantation etc.) ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary High-resolution a.c. magnetic-susceptibility measurements have been performed on sintered samples of Mg-doped YBCO superconductors YBa2(Cu1−x Mg x )3O7−δ (δ≤0.08, 0≤x≤0.1). An estimation of the intergranular shielding currentsJ s (T, H d.c.) has been obtained by separating the grains and coupling-junctions contributions to the measured susceptibility. The results show that Mg doping increases the weak links weight and reduces the values ofJ s. AtH d.c.=0,J s (T, 0) follows a power law of the type (1−T/T c)β, with β varying from 2 (undoped sample) to about 5 (x=2.5%). The dependence ofJ s on the applied d.c. magnetic field can be fitted to a Lorentzian lineshape whose width appears to be independent of the substitution level.
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