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  • 2015-2019
  • 1995-1999  (25)
  • 1975-1979  (132)
  • 1935-1939
  • 1925-1929
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  • 1
    ISSN: 1432-1106
    Keywords: Key words Acetylcholine receptor ; Nicotinic ; Denervation supersensitivity ; Neuromuscular junction ; α-Bungarotoxin ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Through the use of biotinylated-bungarotoxin and monoclonal antibodies, the nicotinic acetylcholine receptor (nAChR) was localized in the subneural apparatus of mammalian motor end plates of the flexor digitorum brevis muscle of the adult rat at the light and electron microscopic levels. Under normal conditions, nAChR was located in the primary post-synaptic membrane of the neuromuscular junction, and the depths of the junctional folds constituting the secondary post-synaptic membrane did not contain any nAChR. Up to 75 days after repeated transection of the related motor nerve (sciatic), there was no major alteration in the light-microscopic localization of junctional nAChR in the subneural apparatus, except for a moderate shrinkage and increased immunocytochemical reactivity of the subneural apparatus. At the electron microscopic level, however, immunocytochemical reactivity gradually occupied the entire extent of the secondary post-synaptic membrane, including the depths of the junctional folds, which exhibited extensive branching. In non-innervated portions of the muscle fibers, nAChR receptor appeared in a linear localization on the surfaces of denervated muscle fibers. This linear reaction was not continuous with the nAChR reaction of the motor end plates. It is concluded that denervation supersensitivity might not be due to spreading of junctional nAChR from the end-plate area, but rather to expression of nAChR in non-innervated portions of the muscle fiber and to the infraterminal (subsynaptic) spreading of nAChR into the depths of junctional folds.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1437-773X
    Keywords: Key words Gastrointestinal stromal tumor ; Gastrointestinal autonomic nerve tumor ; Electron microscopy ; Immunohistochemistry ; Gastrointestinal tract
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Sixteen gastrointestinal stromal tumors (GISTs) were studied by immunohistochemical analysis and an ultrastructural procedure. The tumor locations were as follows: esophagus (2), stomach (7), small intestine (3), and large intestine (4). Four of the lesions were classified as malignant, 2 as borderline, and 10 as benign. On the basis of the immunohistochemical analysis, the tumors were classified as follows: 1 as myogenic type, 2 as Schwann cell type, 8 as Cajal cell type (including 2 gastrointestinal autonomic nerve tumors, GANTs), and 5 as mixed-cell type. In each subtype the phenotype was compared to the ultrastructural findings. Myogenic and Schwann cell type revealed ultrastructurally smooth muscle differentiation and schwannian tumor. All 8 tumors of the Cajal cell type revealed interdigitating cytoplasmic processes with occasional clusters of filopodia. Two tumors were subdivided as GANT. Five tumors of mixed-cell type were composed of a mixture of cells with variable myogenic features or variable neural differentiation. We confirmed in this study that immunohistochemical analysis reflected electron microscopic findings.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Medical electron microscopy 32 (1999), S. 209-212 
    ISSN: 1437-773X
    Keywords: Key words Keratin ; Bile canaliculi ; Ecto-ATPase ; Transgenic mice ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Keratin 8 (K8) and keratin 18 are the intermediate filament proteins that are expressed in hepatocytes. A K8-deficient FVB/N mouse is a unique animal model for assessing the contribution of keratin intermediate filaments (IFs) to the structural and functional integrity of hepatocytes. Hepatocytes from homozygous (−/−) K8-deficient mice manifest a reduced bile acid secretion and an increased fragility to mechanical stress and hepatotoxic drugs. Hepatocytes from heterozygous (+/−) mice are more susceptible to drug-induced injury. Immunofluorescent microscopy revealed that hepatocytes from (+/−) mice maintained K8 IFs and F-actin that are similar to those in wild-type (+/+) mouse hepatocytes. In (−/−) mouse hepatocytes, K8 protein was negative and F-actin presented a coarse and irregular pattern. Ecto-ATPase, detected by enzyme histochemistry and observed by electron microscopy, was reduced in the bile canaliculi of both (+/−) and (−/−) mouse livers, in comparison with that of (+/+) mouse livers. These results reveal for the first time different microscopical findings regarding the livers of these three genotypes. They also suggest that the reduction of ecto-ATPase plays a role in the increased fragility of (+/−) and (−/−) mouse livers.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1437-773X
    Keywords: Key words Small cell neuroendocrine carcinoma ; Parotid gland ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A case of small cell neuroendocrine carcinoma of the parotid gland is presented with immunohistochemical and electron microscopic studies. Small cell neuroendocrine carcinoma is extremely rare and is often difficult to distinguish from malignant lymphoma, adenoid cystic carcinoma, and undifferentiated carcinoma. Under light microscopy, the tumor cells consisted of solid sheets and nests of small tumor cells. Immunohistochemically, they were positive for KL-1 and EMA, and focally positive for NSE and synaptophysin. Observation using an electron microscope showed membrane-bound neuroendocrine granules in some tumor cells. Histological evaluation indicated that the present case was small cell carcinoma of the parotid gland, showing a neuroendocrine variety.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Medical electron microscopy 32 (1999), S. 167-174 
    ISSN: 1437-773X
    Keywords: Key words Apoptosis ; Docetaxel ; Human leukemia cell ; DNA fragmentation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We induced apoptosis in cells of the human leukemia cell line HL-60 using an antitumor agent, docetaxel (Taxotere), and investigated apoptosis in various aspects using in situ end-labeling (ISEL) of DNA, DNA fragmentation assay, flow cytometry, and electron microscopy. Because it inhibits depolymerization of tubulin, docetaxel is thought to arrest the cell cycle at the mitotic stage and to exert an antitumor effect. In this study, accumulation of docetaxel-treated cells at the G2/M phase was detected using flow cytometry. On ISEL of DNA, DNA fragmentation was observed at the mitotic stage. On electron microscopy, the nuclei of apoptotic cells lost their nuclear membranes, as do cells at mitosis, demonstrating that the cells were arrested mainly at the M phase in the cell cycle.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-2307
    Keywords: Key words Melanin ; Oncocytic metaplasia ; Nasopharynx ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  A 64-year-old man presented with a history of discomfort of the throat of a few weeks’ duration. Nasoscopic examination revealed multiple small, brown pigmentations at the left suprapharynx, the base of the left nasal cavity and the pharyngeal openings of the auditory tube on both sides. Microscopically, the lesion showed a glandular pattern of oncocytic epithelium with abundant pigmented granules and melanophages in the surrounding stroma. Immunohistochemically, the dendritic cells in the basal layer were positive for S-100 protein. Electron microscopic study revealed numerous fully melanized melanosomes and hypertrophied mitochondria in the oncocytic cells. Oncocytic cells do not produce melanin for themselves, melanin granules apparently being transferred from the adjacent dendritic cells to the oncocytic cells.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 200 (1999), S. 551-558 
    ISSN: 1432-0568
    Keywords: Key words Retina ; Development ; Retinal pigment epithelium ; Microglia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Blood-borne mononuclear cells invade the developing retina via the hyaloid vasculature at the optic nerve head. Following removal of apoptotic cell debris they give rise to the network of resident microglia. The population of cells recently described in the peripheral subretinal space of developing human eyes may represent a further population of macrophages destined to become microglia. The aim of the present study was to confirm the presence of subretinal macrophages in the developing eye in other mammalian species and perform preliminary immunophenotypic analysis in rat tissues. The range of species chosen included eutherian mammals (rat and rabbit) and marsupials (wallaby and opossum). Ocular tissues from a range of developmental stages were studied by scanning electron microscopy and transmission electron microscopy. Distinctive networks of dendriform and pleomorphic macrophages were observed by scanning electron microscopy in the peripheral subretinal space of D2 rabbits, newborn and D2 rats and D75 wallaby. Transmission electron microscopic studies of D2 rabbit, newborn and D2 rat and all ages of North American opossum revealed cells with the ultrastructural features of macrophages in the peripheral subretinal space, cilio-retinal junction and between ciliary epithelial cells. Preliminary immunoperoxidase studies using a panel of anti-leukocyte monoclonal antibodies on frozen sections of rat ocular tissues (newborn, D2 and D4) revealed ED1+ Ox42+ ED2+ but Ox6– cells in the peripheral subretinal space, peripheral retina and ciliary body epithelia. The data confirms that subretinal macrophages are a feature of the developing eye in a broad range of mammalian species and immunophenotypic evidence leads the author to postulate that these cells arise from the ciliary body vasculature and may migrate into peripheral neural retina and mature into resident microglia.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 98 (1999), S. 645-650 
    ISSN: 1432-0533
    Keywords: Key words Amyotrophic lateral sclerosis ; Autopsy ; Electron microscopy ; Immunocytochemistry ; Motor ; neuron disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report two autopsy cases of motor neuron disease (MND) patients with an unusual type of muscular atrophy predominantly affecting the shoulder girdle and the upper extremities with proximal dominance. Both patients are considered to be clinically categorized into the El Escorial suspected form of amyotrophic lateral sclerosis (ALS). At autopsy, they showed marked loss of spinal anterior horn cells accompanied by astrogliosis positively immunostained with anti-glial fibrillary acidic protein antibody at the cervical level. At the lumbosacral level, anterior horn neurons were relatively well preserved and Bunina bodies, ubiquitin-positive skein-like inclusions and Lewy body-like inclusions were observed in the remaining neurons. In one patient, brain stem motor neurons (nerves V, VII, XII) and motor cortex, including Betz cells, were also affected and the corticospinal tracts were degenerated at the level of the thoracic and lumbar spinal cord. Pathological findings of this patient are consistent with those of ALS. In the other patient, the motor cortex, brain stem motor nuclei and the corticospinal tracts were well preserved, which is pathologically compatible with progressive spinal muscular atrophy. These patients with such a peculiar pattern of progressive muscular atrophy should be placed in a subgroup of ALS.
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  • 9
    ISSN: 1432-0568
    Keywords: Key words Vomeronasal organ ; Microvilli ; Monoclonal antibody ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The development of the rat vomeronasal organ was studied morphologically and immunocytochemically, using the monoclonal antibodies (MAbs) VOBM1, VOBM2 and VOM2 that react with the luminal surface of the vomeronasal sensory epithelium. Postnatal day (P) 7, 14, 21, 28, 35 and adult animals were examined. The vomeronasal organ and the blood vessel of the organ markedly increased in size and the vomeronasal glands increased in number between P7 and P14. At P35, the shape of the vomeronasal organ was similar to that of the adult but its size was slightly smaller. Electron microscopy showed that only a few scattered microvilli were present on supporting cells, and receptor cells were immature at P7. At P21, well-branched microvilli of the receptor cells and many microvilli of the supporting cells were observed on the luminal surface of the sensory epithelium. At P35, most apical endings of supporting cells and receptor cells were covered with numerous microvilli. Less developed areas were also present at the luminal surface of the epithelium at P35. At P7, immunoreactivities of the three antibodies were observed as discontinuous thin-layered bands only on the luminal surface of the sensory epithelium and no immunoreactivity was observed in other regions of the vomeronasal organ. Immunoreactivities of the VOBM1, VOBM2 and VOM2 increased with age and were observed as continuous thin-layered bands on the luminal surface of the epithelium by P35. These finding suggest that the development of the vomeronasal organ continues after birth and that the organ may reach maturity just before puberty (P42–49).
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  • 10
    ISSN: 1432-0533
    Keywords: Key words Unmyelinated fibers ; Peripheral nerve ; Electron microscopy ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Quantitation of unmyelinated fibers (UF) in peripheral nerves has classically relied upon ultrastructural morphometry. Because this method is time-consuming, it is not typically performed in routine analysis of nerve biopsies. We applied the Bodian-Luxol technique to detect unmyelinated axons by light microscopy on semithin sections from resin-embedded nerve tissue. Estimates were compared to ultrastructural counts. The staining appeared highly specific for axons. Excellent correlation was found between optic densities and the population of UF larger than 0.5 μm. The smallest profiles detected by light microscopy had a diameter close to 0.6 μm. This new technique is not a substitute for ultrastructural quantitative morphometry of UF, as very small unmyelinated axons, especially regenerating ones, can not be reliably visualized. However, it provides a valuable light microscopic method for evaluating axonal loss among UF.
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 98 (1999), S. 330-336 
    ISSN: 1432-0533
    Keywords: Key words Micropolygyria ; Electron microscopy ; Frontal lobe ; Perivascular space ; Dot-like structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We have reported breaches of glia limitans (GL)-basal lamina (BL) complex with protruding neuroglial tissue in Fukuyama-type congenital muscular dystrophy (FCMD) fetus brain and suggested that some basic deficits in the GL-BL complex may have a pivotal role in formation of micropolygyria in FCMD. We therefore investigated the cerebral GL-BL complex in seven FCMD cases (12–27 years of age), in three cases of Duchenne muscular dystrophy (17–25 years of age) and in two non-neurological controls (28 and 33 years of age). The frontal lobe cortex was examined immunocytochemically using antibodies against collagen type IV and laminin in each case, and ultrastructurally in an adult case of FCMD. In FCMD, the BL of the cortical surface was frequently breached with protruding neural tissue that ultrastructurally showed frequent synapses, neurites that had parallel arranged microtubules, and astrocytic processes. The outermost surface of this tissue was only partly lined by a BL. In the region of the gyral adhesion of micropolygyria, the perivascular space of the apparently entrapped meningeal blood vessels was occupied by neuroglial tissue, which is assumed to have invaded through the occasionally seen breaches of the perivascular GL-BL complex. Electron microscopy of the intruding tissue showed frequent synapses, microtubule-containing neurites and astrocytic processes. No breached GL-BL complex was found in any of the non-FCMD cases. These findings indicate that in FCMD, the cerebral GL-BL complex continues to have a crucial deficit with resulting breaches through which neuroglial tissue protrudes, promoting adhesion of the adjacent cerebral gyri during brain development before and after birth.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 199 (1999), S. 459-469 
    ISSN: 1432-0568
    Keywords: Key words Differentiation ; Electron microscopy ; Histochemistry ; Microtubules ; Neurofilaments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The organization of the cytoskeleton has been studied during mouse differentiation in cells of the myenteric neuronal lineage. The entire gut was examined starting from day 12.5 of embryonic life (E12.5) until birth (P0). Immunocytochemistry was performed to evaluate the expression of five of the most represented neurofilaments proteins (the low, NF-L, medium, NF-M, and heavy, NF-H, molecular weight subunits, α-internexin and peripherin) and of two of the microtubule-associated proteins (MAP1 and MAP2a+2b). In parallel, the appearance in the differentiating myenteric neurons of filamentous and microtubular structures and their intracytoplasmatic distribution were observed under the electron microscope. A differential immunohistochemical expression of the structural proteins was found. Immature cells expressed α-internexin, peripherin, NF-M and MAP1 by day E12.5; α-internexin expression was strong in these cells, but gradually decreased with age and was practically absent in adulthood. Conversely, the expression of the other three proteins increased with cell differentiation and was still present in adulthood. NF-L and NF-H expression appeared later, by day E16.5, and was weak for the entire pre- and postnatal life. MAP2a+2b was never expressed. Under the electron microscope, at day E12.5 the cytoskeleton was already organized in filamentous and microtubular structures. At this age neurofilaments were few and mainly located in the cell processes, and microtubules were numerous and mainly assembled in the neuritic growth cones, together with synaptic vesicles. With ageing, neurofilaments and microtubules were ubiquitous in the neuron. Data obtained demonstrate that cytoskeletal proteins gradually accumulate in the cells of the neuronal lineage in parallel with the organization of the cytoskeletal structures, which in turn mediate important neural events by the earliest stages of murine embryonic life, including growth of nerve processes and initiation of axonal transport.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 125 (1999), S. 19-27 
    ISSN: 1432-1106
    Keywords: Key words Nerve injury ; Nerve repair ; Retrograde reaction ; Regeneration ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Peripheral axotomy of adult cat spinal motoneurons induces a marked loss of synaptic boutons from the cell bodies and dendritic trees. The aim of the present study was to analyze the recovery of synaptic contacts in axotomized motoneurons following reinnervation into muscle. Adult cat spinal motoneurons were first deprived of their muscular contacts for 12 weeks and, then, allowed to reinnervate their target muscle. Two years later, regenerated motoneurons were labeled with horseradish peroxidase to allow quantitative ultrastructural analyses of the synaptic covering of the cell bodies and dendrites. Presynaptic boutons were classified according to their size and the shape of their synaptic vesicles. Results show that a recovery of synaptic covering occurs in the axotomized neurons after muscle reinnervation, but it affects various bouton types to different degrees. The number of S-type boutons synapsing with the soma was 70% higher after reinnervation than at 12 weeks after axotomy, while the number of F-type boutons had increased by only 13%. Compared with the normal situation, the number of S-type boutons synapsing with the proximal dendrites increased from 82% at 12 weeks after axotomy to 180% in the reinnervated state. In conclusion, in adult cat spinal motoneurons, the reestablishment of muscular contact is followed by a normalization of some of the synaptological changes induced by a prolonged state of axotomy. In certain respects restitution is incomplete, but in others it results in overcompensation.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    European biophysics journal 28 (1999), S. 263-267 
    ISSN: 1432-1017
    Keywords: Key words Human liver ; Human brain ; Ferritin ; Electron microscopy ; Mössbauer spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract Human brain (globus pallidus) and liver tissues were investigated by means of electron microscopy (EM), Mössbauer spectroscopy (MS) and SQUID magnetometry techniques. Based on MS measurements, the iron present was identified to be in the ferritin-like form (61–88%) and in the form of a low-spin iron species (the balance). Its overall concentration was estimated as 1.5(3) mg in the brain and 2.4(5) mg in the liver, per gram of lyophilized tissue. The average core diameter was determined by EM measurements to be equal to 7.5(1.3) nm for the liver and 3.3(5) nm for the brain. Magnetization measurements carried out between 5 and 300 K yielded an estimation of an average blocking temperature, KT BL, as equal to 6.7 K and 8.5 K for the liver and the brain, respectively. From the dependence of KT BL on the external magnetic field it was concluded that the ferritin-like cores in the studied samples can be regarded as non-interacting particles. Finally, the uniaxial magnetic anisotropy constant was determined to be 6×103 J/m3 for the liver and 4×104 J/m3 for the brain.
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  • 15
    ISSN: 1432-1459
    Keywords: Key words CADASIL ; Cerebrovascular disease ; Skin biopsy ; Muscle biopsy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a microangiopathic syndrome. Although the defective gene has been identified, genetic analysis may be effort some due to its large size and various mutations. Providing a reliable diagnostic marker would therefore be helpful. Electron microscopy has revealed characteristic electron-dense granular deposits in the basal lamina of vessels of patients with CADASIL. We investigated the sensitivity of skin and muscle biopsies for diagnosing CADASIL. We examined 30 family members of three unrelated German families affected by CADASIL. In 14 of the 21 affected individuals we performed skin and muscle biopsies; two patients were clinically asymptomatic. Under electron microscopy all muscle and skin biopsy specimens showed patches of granular and electron-dense material in the basal layer of both arterioles and capillaries. These findings confirm that general microangiopathy is a typical feature of this syndrome and is present in the early phase of the disease with or without clinical manifestation. Thus, as electron microscopy of skin biopsy specimens can establish the diagnosis of CADASIL with high certainty, it may be considered the method of first choice.
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  • 16
    ISSN: 1432-2307
    Keywords: Key words Rhabdomyosarcoma ; Aorta ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  We report an intimal sarcoma presenting as an aortic aneurysm. A 68-year-old man suffered from chest pain and speech disturbance. Computed tomography showed a sacciform aneurysm of the aorta, which was resected, revealing a polypoid tumour measuring 1.5×2×2.5 cm projecting into the lumen. This proved to be a poorly differentiated high-grade sarcoma having morphological, immunophenotypic and ultrastructural features consistent with rhabdomyosarcomatous differentiation. Primary sarcomas of the aorta are extremely rare. Many cases have been diagnosed as ”intimal” on the basis of their site of origin, and they are not easy to classify from their histological pattern. Electron microscopy and the use of a more comprehensive panel of immunohistochemical markers should be applied in the histological classification of ”intimal” sarcoma.
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  • 17
    ISSN: 1432-0878
    Keywords: Key words Descending contralateral movement detector (DCMD) ; Identified neuron ; Vesicles ; Electron microscopy ; 3-D reconstruction ; Locust ; Schistocercagregaria (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The descending contralateral movement detector (DCMD), an identified descending interneuron in the brain of the locust Schistocerca gregaria has been investigated by using light and electron microscopy. We describe the fine structure, distribution and numbers of synapes that it receives from another identified brain neuron, the lobular giant movement detector (LGMD), and from unidentified neurons. The DCMD dendrites emerging from the integrative segment vary in form and number between individuals and sexes but always form a flattened dendritic domain. The arborizations and the integrative segment appear to be exclusively postsynaptic. Two types of synaptic contacts (Type 1 and 2) onto the DCMD can be discerned as having either round (Type 1) or pleiomorphic synaptic vesicles (Type 2) and by large (Type 1) or small (Type 2) subsynaptic appositions. Contact zones of Type 1 synapses are smaller than those of Type 2. LGMD-synapses are of Type 1 and occur intermingled with presynaptic sites of unidentified units. Some branches of the DCMD receiving input from unidentified units are devoid of contacting LGMD processes. Synapses of both types are randomly distributed over the DCMD integrative segment and at fibres with similar sizes.Type 1 synapses are much more frequent than Type 2 synapses and their number is negatively correlated with fibre diameter. For a whole DCMD dendritic arborization, a total of 8500 active zones of chemical synapses has been calculated, including a mininum of 2250 LGMD-synapses and about 1000 Type 2 synapses. The DCMD may thus receive a considerable amount of input from as yet unidentified neurons.
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 296 (1999), S. 359-369 
    ISSN: 1432-0878
    Keywords: Key words Apoptosis ; Electron microscopy ; Meiosis ; Spermatocytes ; Spermatogenesis ; Testis ; TUNEL ; Mouse (10 strains)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Apoptosis of male germ cells is a widespread but little-understood phenomenon in many animal species. The elucidation of its mechanisms could be useful in the understanding of male infertility. We have examined the distribution of dying cells with the terminal transferase-mediated nick-end labeling (TUNEL) method and by an electron-microscopic procedure in the testes of 10 mouse strains, viz., C57BL/10 (B10), SL/NiA (SL), C57BL/6 (B6), C3H/He (C3H), BALB/c (BALB), DBA2 (DBA), CBA/J (CBA), MRL/MpJ-+/+ (M+), MRL/MpJ-lpr/lpr (lpr), and wild-type NJL mice (Mus musculus musculus). In the testes of the B10, NJL, SL, B6, C3H, BALB, DBA, and CBA mice, very few TUNEL-positive cells are distributed in the seminiferous tubules, whereas in the testes of the M+ and lpr mice, many TUNEL-positive cells, which are restricted to stage XII seminiferous tubules, have been identified. The most important finding is that many metaphases of meiotic spermatocytes show a marked TUNEL-positive reaction. Some metaphases show apoptotic morphology electron-microscopically. These results suggest that the testes of MRL strains will provide a useful model for the study of the mechanism of metaphase-specific apoptosis in meiotic spermatocytes.
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  • 19
    ISSN: 1432-0878
    Keywords: Key words Neuromelanin ; Neuron ; Peroxidase ; Oxygen metabolism ; High-definition light microscopy ; Electron microscopy ; Ultrastructure ; Cytochemistry ; Substantia nigra ; Lumbricusterrestris (Annelida)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Histochemical examination of 1-μm tissue sections from the dorsal nerve plexus of the earthworm, Lumbricus terrestris, reveals multiple brown intraneuronal granules. These granules contain material morphologically and histochemically consistent with neuromelanin. When viewed with transmission electron microscopy, these were seen as single membrane-enclosed biphasic granules with diameters of 370–730 nm. Exposure of L. terrestris to high-level environmental oxygen resulted in an increase in the number of neuromelanin-like pigment granules within the neurons of the circular muscle layer. As measured by ortho-phenylenediamine hydrochloride, the endogenous peroxidase activity of extracts from worms incubated in high-level environmental oxygen was 51% more than controls. The endogenous peroxidase activity was localized in situ with 3,3-diaminobenzidine (DAB) and was found to increase in and around the neuromelanin-like pigment-containing neurons within the circular muscle layer. These studies suggest that the nerve net of L. terrestris may serve as a model to study the role of neuromelanin production in oxidative stress and its relationship to endogenous peroxidases.
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  • 20
    ISSN: 1432-0878
    Keywords: Key words Immunohistochemistry ; Electron microscopy ; Interstitial cells of Cajal ; F4/80 ; CSF-1 ; Kit-receptor ; Mouse (op/op)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The osteopetrotic (op/op) mutant mouse possesses an inactivating mutation in the colony-stimulating factor-1 (CSF-1) gene, which results in the absence of certain macrophages and in osteopetrosis, following a lack of osteoclasts. Studies of the op/op mouse indicate that CSF-1-dependent tissue macrophages may belong to a trophic and/or scavenger subpopulation, which through their effect on other cell types can significantly affect tissue functions, and that cells which are CSF-1 independent have antigen presentation and immunological functions.We have previously identified a cell system of regularly distributed macrophages in the muscularis externa of the small intestine and wanted to extend these studies to the op/op mouse.The present investigations with light- and electron-microscopic methods using fluorescent dextran, methylene blue and immunohistochemistry (F4/80, anti-kit receptor, anti-CD3, anti-CD45R/B220) show that macrophages are absent from the muscle layers, with only an occasional macrophage present in the subserosa. In the lamina propria and submucosa, macrophage numbers are reduced. In all other respects the muscularis externa appears normal, including normal organization and number of interstitial cells of Cajal. Control and op/op mice both lack cells expressing CD3 (T lymphocytes), CD45R/B220 (B lymphocytes) and mast cells in the muscularis externa. This leaves the muscularis externa macrophages as the most likely source of local cytokine production under such conditions as postoperative ileus and intussusception in infants, where the muscularis externa appears to be one target of cytokines. We conclude that the lack of macrophages, combined with the preservation of otherwise normal structure, will make the op/op mouse a valuable model by which to assess the functions and relative importance of the muscularis externa macrophages in relation to intestinal motility under normal and pathological conditions.
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  • 21
    ISSN: 1432-0878
    Keywords: Key words Caveolin ; Caveolae ; Lung ; Alveolar epithelial type I cell ; Immunocytochemistry ; Electron microscopy ; Confocal laser scanning microscopy ; Rat (CD)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Caveolae are flask-shaped invaginations of the plasmalemma which pinch off to form discrete vesicles within the cell cytoplasm. Biochemically, caveolae may be distinguished by the presence of a protein, caveolin, that is the principal component of filaments constituting their striated cytoplasmic coat. Squamous alveolar epithelial type I (ATI) cells, comprising approximately 95% of the surface area of lung alveolar epithelium, possess numerous plasmalemmal invaginations and cytoplasmic vesicles ultrastructurally indicative of caveolae. However, an ultrastructural appearance does not universally imply the biochemical presence of caveolin. This immunocytochemical study has utilised a novel application of confocal laser scanning and electron microscopy unequivocally to localise caveolin-1 to ATI cells. Further, cytoplasmic vesicles and flask-shaped membrane invaginations in the ATI cell were morphologically identified whose membranes were decorated with anti-caveolin-1 immunogold label. Coexistent with this, however, in both ATI and capillary endothelial cells could be seen membrane invaginations morphologically characteristic of caveolae, but which lacked associated caveolin immunogold label. This could reflect a true biochemical heterogeneity in populations of morphologically similar plasmalemmal invaginations or an antigen threshold requirement for labelling. The cuboidal alveolar epithelial type II cell (ATII) also displayed specific label for caveolin-1 but with no ultrastructural evidence for the formation of caveolae. The biochemical association of caveolin with ATI cell vesicles has broad implications for the assignment and further study of ATI cell function.
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  • 22
    ISSN: 1435-1536
    Keywords: Key words Double chain surfactants ; Aggregates ; Phase diagrams ; Lamellar phases ; Electron microscopy ; SANS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract We present the phase diagrams and the properties of newly synthesised double-chain cationic N-alkyl-N-alkyl′-N,N-dimethylammonium bromide surfactants [C x C y DMABr (x = 12, 14 and 16; y = 10, 11, 12, 14 and 16)]. All the systems studied form liquid-crystalline lamellar phases but with different morphologies: unilamellar vesicles at low surfactant concentrations, multilamellar vesicles and tubular aggregates for surfactant concentrations between 2 and 10 wt% and at even higher concentrations planar bilayers of surfactant molecules in the classical Lα phase. The phase diagrams were determined with macroscopic and microscopic methods (polarisation microscopy, freeze-fracture transmission electron microscopy, scanning electron microscopy and differential interference contrast microscopy). The properties of the surfactant solutions were determined with differential scanning calorimetry measurements for Krafft point determination and small-angle neutron scattering measurements for interlamellar spacing and bilayer thickness. Finally, conductivity and viscosity measurements for phase characterisation were carried out.
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  • 23
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    European journal of epidemiology 15 (1999), S. 175-180 
    ISSN: 1573-7284
    Keywords: Electron microscopy ; Epidemiology ; Non-bacterial Gastroenteritis ; Oyster ; Small round structured viruses (SRSVs)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract From 1987 to 1992, 18 outbreaks of acute non-bacterial gastroenteritis occurred in Kyushu district. The most common symptoms were diarrhea, vomiting, nausea and abdominal cramp. Small round structured viruses (SRSVs) were detected in 52 (44.8%) of 116 stool samples from 17 outbreaks by the electron microscopy (EM) method, and a significant increase in the antibody level was noted in 42 (80.7%) of 52 paired serum samples from 12 outbreaks by the immune electron microscopy (IEM) method and in 18 (51.4%) of 35 samples from 8 outbreaks by the western blot (WB) method. However, according to the WB method, antigen-antibody reaction was not observed to reference antigen strips (SRSV-9/Tokyo 86-510, 63kDa) in three of the 8 outbreaks. The detected virus was regarded as an etiologic agent for these outbreaks. In four of 5 outbreaks which appeared associated with eating raw oysters, there was a close relation between SRSV infection and consumption of raw oysters.
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  • 24
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    Colloid & polymer science 277 (1999), S. 164-173 
    ISSN: 1435-1536
    Keywords: Keywords Nanostructures ; Thin films ; Vapor deposition ; Electron microscopy ; Optical properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Colloidal dispersions of Yb, Er and Pr have been prepared by chemical liquid deposition. The metals were cocondensed at 77 K with 2-methoxyethanol and ethanol to produce solvated metal atoms. The particle size of the dispersions was determined by transmission electron microscopy to range from 52 to 1080 Å; the particles had spherical shapes. After solvent evaporation under vacuum, active solids and amorphous powder were deposited over Cu and Al metal. Dispersion stability, particle size, UV/Vis absorption and zeta potential were studied. The solids prepared by solvent evaporation were characterized by Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The films prepared on Al were studied by scanning electron microscopy. The most stable colloid was obtained using 2-methoxyethanol: several concentrations were stable for several months and the zeta potential indicated that this colloid stability is mainly due to solvation effects. FTIR spectroscopy of the solids indicated solvent incorporation in the film. This observation was corroborated by thermal analysis. Information on the thermal stability of the films was obtained by TGA. The UV/Vis absorption spectrum was measured at several concentrations under different conditions.
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  • 25
    ISSN: 1434-4726
    Keywords: Key words Laryngeal cancer ; p53 ; Oncoprotein ; Ki67 ; Proliferating cell nuclear antigen (PCNA) ; DNA ploidy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The difficult and complicated mechanism of cancer development with little knowledge about the biology of existing cancers can lead to a permanent search for new examination techniques to improve the precision of life expectancy in patients and the selection of the most efficient methods of treatment. The aim of this study was to analyze certain prognostic factors, i.e., p53, Ki67, proliferating cell nuclear antigen (PCNA), DNA ploidy and cell proliferating activity, as well as the degree of morphological differentiation and cell maturity evaluated on an ultrastructural level in patients with laryngeal cancers in connection with data obtained from follow-up examinations and the clinical course of the disease. Neoplastic tissue was taken from 120 patients with laryngeal cancers. All underwent surgical treatment, radiotherapy and combined treatment in the Department of Otolaryngology, Karol Marcinkowski University School of Medical Sciences, Poznań, Poland, and the Department of Otolaryngology – Head and Neck Surgery, Haukeland University, Bergen, Norway. Before beginning treatment all patients underwent histological verification of their neoplastic tissues. Histopathological examination proved that the majority of cases (95%) had a squamous cell carcinoma. The occurrence of changes within the lymph nodes of the neck (N) was significantly correlated with T, S, Ki67, metastases to lymph nodes, DNA ploidy, site and surgery performed. The degree of clinical progression (S) was intercorrelated with T, N, p53, Ki67, PCNA, DNA ploidy, site and laryngectomy. The occurrence of oncoprotein p53 in neoplastic cells was measured by the staining degree of their nuclei and was correlated with T, S, DNA ploidy, metastases to lymph nodes, PCNA and site. The degree of staining of neoplastic cells for the nuclear antigen Ki67 was correlated to T, N, G, S, DNA ploidy, metastases to lymph nodes and surgical treatment. The proliferative antigen PCNA in the examined population of patients was intercorrelated with T, p53, Ki67, metastases to lymph nodes and surgical treatment. The results obtained from DNA flow cytometry could be associated with N, G, p53, Ki67 and metastases to lymph nodes. On the basis of the results obtained, the techniques suggested for the morphological and biological evaluation of neoplastic cells in cancer of the larynx should include TNM classification + G + DNA + p53 + Ki67.
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  • 26
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    Archives of gynecology and obstetrics 223 (1977), S. 195-204 
    ISSN: 1432-0711
    Keywords: Electron microscopy ; Human endometrium ; Nucleus ; Nucleolus ; Channel system ; Elektronenmikroskopie ; Menschliches Endometrium ; Nukleus ; Nukleolus ; Channel-System
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das Nuclear-Channel-System ist eine runde bis ellipsoide Struktur, deren Tubuli querangeschnitten oder längsangeschnitten in eine elektronendichte Matrix eingebettet sind. Das NCS liegt meist der Kernmembran dicht an, die in diesem Bereich Einziehungen aufweist. Gelegentlich ist ein Kontakt der Kernmembran mit der Membran eines Tubulus zu beobachten. Im NCS sind Partikel festzustellen, die den 150 Å großen Partikeln des Nucleolus vergleichbar sind, was auf einen Gehalt des NCS an RNA schließen läßt. In hier vorliegenden Untersuchungen konnte das NCS in Zellkernen endometrialer Drüsenzellen während der mittleren und späten Proliferationsphase beobachtet werden. Diese Befunde sprechen gegen eine zwingende Abhängigkeit des Auftretens des NCS vom Zeitpunkt der Ovulation. Das NCS kann somit nicht als eine für postovulatorisches Endometrium typische Struktur angesehen werden. Offensichtlich bestehen zwischen den hormonellen Faktoren und der Ausbildung des NCS Beziehungen, deren Bedeutung bis heute nicht sicher beurteilt werden kann.
    Notes: Summary The Nuclear Channel System (NCS) is a distinct endometrial pattern as observed by transmission electron microscopy. The NCS was identified in the present study in cell nuclei of endometrial glands during mid and late proliferation. These observations do not support the concept that the NCS develops at the ovulation, and is therefore not a typical post ovulatory structure. It is suggested that there are relations between hormonal factors and the development of the NCS which are as yet no clarified.
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  • 27
    ISSN: 1432-0711
    Keywords: Electron microscopy ; Stereology ; Human liver ; Oral contraceptives ; Elektronenmikroskopie ; Stereologie ; Menschliche Leber ; Orale Kontrazeptiva
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wurden Leberbiopsien von 12 Frauen feinstrukturell-morphometrisch untersucht, die über einen Zeitraum von 2 Monaten bis zu 8 Jahren ein Kombinationspräparat zur hormonellen Antikonzeption eingenommen hatten. Die stereologischen Daten wurden bereits vorher erstellten Basiswerten für normale Lebern (Roessner et al., 1977) gegenübergestellt und auf signifikante Unterschiede hin überprüft (p〈0,001). Eine deutliche Volumenzunahme lysosomaler Zelleinschlüsse pro ml Hepatocyten und eine leichte Cytoplasmavergrößerung bei gleichzeitiger Verkleine-rung der Nuclei kennzeichnen die Veränderungen der Hepatocyten. Alle übrigen ermittelten Parameter lassen den Schluß zu, daß wesentliche Alterationen der Ultrastruktur der menschlichen Leber nach hormoneller Kontrazeption nicht auftreten. Ob damit auch funktionelle Alterationen auszuschließen sind, kann hier nicht beantwortet werden.
    Notes: Summary Liver biopsies from 12 healthy women were investigated morphometrically — according to the methods of Weibel (1969). All women had taken an oral contraceptive agent during 2 til 76 months. The evaluated stereological datas were compared with base-line datas for normal human liver biopsies, which were elaborated in a previous investigation (Roessner et al., 1977). Statistical analysis was performed on an IBM 360/50 computer system, including F- and student's t-test. In the liver biopsy-specimen from the women, which were on oral contraceptives, the volume-density of lysosomes per ml hepatocytes shows a pronounced, significant (p〈0.001) increase. A moderate increase of cytoplasm is combined with decrease of nuclei-volume. The surface-densities of the rough and smooth endoplasmatic reticulum do not differ significantly from the datas calculated from normal human liver biopsies. All other datas too demonstrate that there are no striking changes in the ultrastructure of human liver, caused by oral contraceptives. Functional alterations however can not be excluded.
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  • 28
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    Archives of dermatological research 259 (1977), S. 225-234 
    ISSN: 1432-069X
    Keywords: Granuloma annulare ; Necrobiosis of collagen ; Palisading granuloma ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Neun Fälle von Granuloma annulare in verschiedenen Entwicklungsstadien wurden elektronenmikroskopisch untersucht, insbesondere Kollagenveränderungen, das entzündliche Infiltrat und Gefäßalterationen. Die nekrobiotischen Veränderungen des Kollagens bestehen in Auflockerung der Bündel vom Rande her, Schwellung der Fibrillen mit Verlust ihrer Querstreifung, völliger Desintegration des Kollagens und Niederschlägen von mucinösen Substanzen, Fibrin und Glykogen. In 2 Fällen waren sogenannte “filamentöse quergestreifte Aggregationen” (= sog. “long-spacing collagen”) nachweisbar. In späteren Stadien zeigte sich Kollagenneubildung. Im Infiltrat sind vor allem Histiocyten/Makrophagen mit Übergängen zu Epitheloidzellen und Riesenzellen, daneben auch Lymphocyten und später Neutrophile identifizierbar. Gefäßveränderungen bestehen in Endothelschwellung und Basalmembranverdoppelungen. Es besteht ein perivasculäres Infiltrat, jedoch keine echte Vaskulitis. Die Ergebnisse sprechen dafür, daß die Nekrobiose des Kollagens ohne primäre Vaskulitis ein initiales Ereignis bei Granuloma annulare darstellt. Pathogenetisch wird ein Immungeschehen vom verzögerten Typ diskutiert.
    Notes: Summary Nine cases of granuloma annulare at different stages of development were investigated electron microscopically. Special attention was given to collagen changes, to the cellular infiltrate, and to vascular changes. The necrobiotic changes of the collagen were: loosening of the fibers at the borders of the bundles; swelling and loss of cross-striation of the fibrils; and complete degradation of the collagen, with precipitation of mucinous and fibrin material and of glycogen. In 2 cases “cross-banded filamentous aggregations” were present. In later stages new collagen synthesis occurred. In the infiltrate, histiocytes/macrophages were seen developing into epithelioid and giant cells. In addition, numerous active lymphocytes and, at later stages, some neutrophils were found. Vascular changes consisted of endothelial swelling and duplications of the basal lamina. A perivascular infiltrate was present, but no distinct vasculitis was seen. Our results indicate that the necrobiosis of the collagen without primary vasculitis may be an initial event in granuloma annulare. A delayed hypersensitivity mechanism is discussed with regard to pathogenesis.
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  • 29
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    Virchows Archiv 373 (1977), S. 191-211 
    ISSN: 1432-2307
    Keywords: Myeloproliferative disorder ; Thrombocytes ; Megakaryocytic-granulocytic myelosis ; Bone marrow biopsy ; Megakaryocyte lineage ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of the bone marrow in chronic megakaryocytic-granulocytic myelosis (CMGM) was studied in 5 nontreated patients to investigate possible malignant proliferation of megakaryocytes and the role of megakaryopoiesis in fibrillogenesis, terminating in osteomyelofibrosis. In comparison with normal megakaryopoiesis there is an enormous increase of the megakaryocytic cell line and many immature and atypical forms are seen. Most conspicuous are microforms, nuclear-cytoplasmic disorganization and nuclear inclusions. Asynchrony of maturation causes abnormal thrombocytogenesis with premature detachment of platelets resulting in immature and peculiar giant forms of thrombocytes. Besides megakaryocytes appearing superficially normal the maturation anarchy of many cells is so severe that by analogy with observations in other leukaemic cells these abnormalities are thought to be representative of a malignant growth. Moreover, there is a striking accumulation of microfibrils and single collagen fibres around megakaryoblasts. Since these cells contain all those organelles commonly associated with fibre production the initial step for fibrillogenesis may therefore arise from the megakaryoblasts prior to platelet release, or any fibroblast proliferation.
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  • 30
    ISSN: 1432-2307
    Keywords: Ulcerative colitis ; Immunoperoxidase ; Complement demonstration ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Inflammatory cell infiltrates in ulcerative colitis have been investigated by means of the immunoperoxidase method and by electronmicroscopy. Considerable morphological and functional changes of the local plasma cell population have been found. The absolute number of plasma cells is raised with a marked increase of IgG-cells and a relative decrease of IgA-cells. In particular complement (C3) has been demonstrated at the basement membrane of the surface epithelium and between epithelial cells. The significance of these findings, as a local humoral immune response, is briefly considered, with regard to their possible pathogenetic importance in aggravating and perpetuating the disease.
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  • 31
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    Virchows Archiv 375 (1977), S. 1-12 
    ISSN: 1432-2307
    Keywords: Adenoid cystic carcinoma ; Cylindroma ; Salivary glands ; Mucosubstances ; Cytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The distribution of mucosubstances in adenoid cystic carcinoma was investigated, and an attempt was made to characterize histochemically the various mucosubstances present. For these purposes the high iron diamine technique (HID), as well as the Astra blue, aldehyde fuchsin and Alcian blue staining methods were employed. Alcian blue was further combined with the periodic acid-Schiff (PAS) technique, the Alcian blue being applied at pH levels between 0.5 and 2.5. In addition the effects of neuraminidase and hyaluronidase treatment as well as methylation and acid hydrolysis procedures on the staining qualities were studied. Acidic mucosubstances with varying histochemical properties were present in different structures of the neoplasm. The characteristic pseudocyst, a major structural component of the neoplasm, stained strongly with HID, Astra blue, aldehyde fuchsin and Alcian blue at low pH. These staining reactions were markedly suppressed by hyaluronidase treatment, and are apparently attributable to the presence of chondroitin 4- and/or 6-sulfate. Employing the Alcian blue-critical electrolyte concentration technique, the basophilia of the pseudocysts was suppressed at a concentration of 0.5–0.6 M MgCl2, which might indicate polysaccharides of relatively low degree of sulfation. An additional, non-sulfated acid mucin could also be demonstrated in these structures. In certain duct and gland like structures of the tumours, a change in staining pattern from blue or blue-red to red could be observed after exposure of the sections to neuraminidase and subsequent staining with the Alcian blue (pH 2.5)-PAS sequence. Similar observations were also made when the pH of the Alcian blue was lowered to 1.5–1.0, as well as after acid hydrolysis. These findings afford evidence for the presence of a neuraminidase susceptive sialomucin in certain epithelial secretions of the tumor. At the ultrastructural level the replicated basement lamina of the pseudocysts displayed a strong positive reaction with the PA-CrA-silver staining technique. Furthermore, amorphous material within the lumina of small duct like structures also displayed a positive reaction. The amorphous material of the cystic compartments was less reactive.
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  • 32
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    Virchows Archiv 375 (1977), S. 123-128 
    ISSN: 1432-2307
    Keywords: Esthesioneuroblastoma ; Light microscopy ; Electron microscopy ; Argyrophil reaction ; Formaldehyde-induced fluorescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of esthesioneuroblastoma was examined by histological, histochemical and electron microscopic techniques. The tumour cells showed an argyrophil reaction with the Grimelius technique and contained cytoplasmic secretory granules, but in contrast to previous reports were devoid of histochemically demonstrable biogenic amines. For routine diagnosis the argyrophil technique may be useful in differentiating this type of tumour from epidermoid carcinoma.
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  • 33
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    Virchows Archiv 375 (1977), S. 13-22 
    ISSN: 1432-2307
    Keywords: Target-targetoid phenomenon ; Histochemistry ; Electron microscopy ; Z-band alteration ; Incomplete innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Target and targetoid fibers in a muscle biopsy from a patient with paralysis of the deltoid and supraspinatus muscles were studied by light and electron microscopy. The probable cause of the neuropathy was tumor compression. Target and targetoid change was exclusively confined to hypertrophic or normal-sized fibers. Morphometric evaluation of the target and targetoid fibers showed no significant difference between them. With the electron microscope, up to 4 structural zones were seen in the typical target fiber but many were devoid of either zone 2 (halo) or zone 3, or both. It was conceivable that focal irregularity and streaming of Z-bands were the primary alterations in the process of target-targetoid fiber formation, and that this phenomenon was induced both by partial residual innervation as well as re-innervation.
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  • 34
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    Virchows Archiv 375 (1977), S. 147-157 
    ISSN: 1432-2307
    Keywords: Electron microscopy ; Atherosclerosis ; Pigeon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The atherosclerotic lesions, associated with the celiac intimal smooth muscle cushions, of four and five year old White Carneau pigeons were studied with the light and electron miscroscopes. Light microscopic examination of the spontaneous lesions demonstrated large intimal cushions composed of smooth muscle, abundant collagen, clusters of foam cells and cholesterol crystal clefts. Ultrastructural examination of the intimal atheroma revealed dilatations between apposing endothelial cells which contained a flocculent material, similar to that seen in the subendothelial space. The subendothelial compartment contained abundant collagen, extracellular lipid, vesiculated material and cell processes which contained a flocculent matrix and tubular-like elements. In addition, fibroblast-like interlaminar cells were often observed. Numerous intimal smooth muscle cells were seen which displayed varied morphology. Abundant foam cells were also present within the intimal atheromas. The presence of atherosclerotic lesions in preexisting intimal smooth muscle cushions suggests that hemodynamic factors may be important in the progression of these spontaneous lesions. Endothelial cell dilatations may provide an important route of transport for circulating elements which may accumulate within the subendothelial space. Morphologically, it appears that the smooth muscle cells undergo modification and may represent the precursors of foam cells in this species.
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  • 35
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    Virchows Archiv 377 (1977), S. 43-48 
    ISSN: 1432-2307
    Keywords: Childhood cystinosis ; Liver ; Electron microscopy ; Dark cells ; Tight junctions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural findings in the liver in a case of childhood cystinosis are reported. Crystalline structures were found mainly in Kupffer cells. The presence of dark cells, with or without crystals, was the most striking feature observed. Such cells have already been noted within the kidney on one occasion when it was shown that the dark substance was L-cystine (Spear et al., 1971). In this case identical dark material was also found extracellularly. The data shows that free cystine can fill cell cytoplasm and extracellular spaces and the possibility that cystine overproduction may take place in the hyaloplasm should be considered. Extracellular location of cystine in the tubules might account for an increase in epithelial permeability and thus for the Fanconi syndrome.
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  • 36
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    Mycopathologia 60 (1977), S. 175-177 
    ISSN: 1573-0832
    Keywords: Aspergillus fumigatus ; Spore formation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
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  • 37
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    Mycopathologia 61 (1977), S. 117-119 
    ISSN: 1573-0832
    Keywords: Prototheca ; Colorless alga ; Plastids ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract An ultrastructural investigation of six different species of Prototheca showed that all of them contained starch grains enclosed in double-membrane-bounded structures recognized as plastids. It is concluded that these unicellular species of Prototheca must be considered as non-photosynthetic algae.
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  • 38
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    Anatomy and embryology 152 (1977), S. 43-64 
    ISSN: 1432-0568
    Keywords: Habenula ; Ependyma ; Supraependymal cells ; Supraependymal axons ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The surface features of the ependymal lining of the habenular complex in rats, aged between three weeks and nine months, were studied by means of scanning and transmission electron microscopy. The ependyma of the medial habenular nucleus is heavily ciliated, the cilia obscuring underlying substructure in SEM — preparations. On the habenular commissure most cilia are arranged in tufts. Cilia are provided with segmental indentations and occasional apical thickenings. Vesicular protrusions of the ependymal cytoplasm into the ventricular lumen and the frequent occurrence of homogeneous supraependymal globules were interpreted as signs of ependymosecretory activity of nucl. hab. med. Supraependymal cells are most numerous on the anterior and superior surface of the habenular commissure. Cells presenting features identical to Kolmer (epiplexus) cells were identified on the ventricular surface of nucl. hab. med. in one specimen showing degenerative changes of undetermined aetiology in the habenular nuclei. It is therefore suggested that such cells need not necessarily be restricted to the choroid plexus. Supraependymal unmyelinated axons are particularly numerous on both nucl. hab. med. and commiss. hab. They make desmosome contacts (maculae adherentes) with the ependymal plasmalemma. Contacts presenting all features of typical synapses were not encountered. The vesicle population of the axonal profiles mainly comprises 35–50 nm translucent round vesicles besides small numbers of 60–100 nm dense-cored vesicles and large pleiomorphic vesicles. Most probably the axons belong to the well-established dense population of serotonergic axons in the dorsal part of the third ventricle.
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  • 39
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    Anatomy and embryology 150 (1977), S. 335-364 
    ISSN: 1432-0568
    Keywords: Caudate nucleus ; Hypothyroidism ; Development ; Electron microscopy ; synaptogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thyroid hormone exerts a powerful influence on CNS growth and maturation. Hypothyroidism early in life has long been known to cause disturbances in innate behavior, motor performance, severe and frequently irreversible mental retardation. In this deficiency, depressed caudate neurogenesis, cell migration and neuropil development during the rapid period of CNS growth may contribute to the clinical picture of perceptual handicaps often seen in cretins. Light microscopic and Golgi studies of the developing caudate nucleus in thyroid deficiency have been carried out to help attain insights into the mechanisms whereby the extrapyramidal system regulates motor function. The ultrastructural study of caudate nuclear cytogenesis and synaptogenesis in normal and hypothyroid states provides more detailed information for further analysis of the problem. Hypothyroidism was induced from birth by adding propylthiouracil to the food and drinking water of lactating dams. Linear development of the caudate nucleus of both normal and hypothyroid rats at ages 8, 14, 20, 30 and 42 days was studied by electron microscopy. Thyroid glands were examined by light microscopy to assess the normal and deficient states. Immature cells, primitive processes and synapses were the characteristic features of the 8-day-old normal caudate nucleus. Distinctively wide cisternae of the rough endoplasmic reticulum, loosely packed Golgi apparatus and chromatin clumps throughout the nuclei of the neurons were significant early morphologic variations. The dramatic cytoarchitectural maturation in the 14- and 20-day normal caudate neuropil points to the rapidity of developmental rate. After the growth spurt of the first three weeks a maturational plateau occurs which is characterized by well-formed neuronal cytoplasmic organelles, myelinated and non-myelinated axons, axon terminals, dendrites and their spines, and synapses. Thyroid deficiency causes a marked maturational delay of approximately 7 days in caudate neuronal proliferation, the elaboration of neuronal networks and the attainment of mature synaptic contents and membranes. This delay is evidenced by comparison of the structural similarities between 8-day-old normal and 14-day-old deficient rats; and additional comparisons between the 14-day-old normal and 20-day-old hypothyroid rats. A rapid “catch up” process in fine structural morphogenesis takes place in the period between days 14 and 30 in the deficient animals. Repression of thyroid function does not entirely prevent development of the caudate nucleus but allows a fairly extensive, though critically incomplete degree of maturation. This imperfection is manifested by a decrease in the number of synaptic contacts that persists even after the rapid “catch up” phenomenon of caudate synaptogenesis.
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  • 40
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    Anatomy and embryology 151 (1977), S. 109-118 
    ISSN: 1432-0568
    Keywords: Iris ; Mesenchymal cells ; Chicken embryo ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The iris anlage of 3–10 day old chicken embryos was studied by both light and electron microscopy. Serial semithin sections showed that some of the mesenchymal cells overlying the eye cup moved into the primitive eye cavity by the 3rd day of incubation. On the 4th day some of these cells came into close contact with the basement membrane of the dorsal iris epithelium. The bases of the epithelial cells were flat at this stage. Towards the 10th day they formed cytoplasmic processes which did not penetrate the basement membrane. Fine mesenchymal cytoplasmic processes and a large number of extracellular fibrils developed in the epithelial-mesenchymal interface. The fine mesenchymal processes came into close contact with the basement membrane of the posterior iris epithelium but did not penetrate it. Collagen-like material was observed within the cisternae of the rough ER of the mesenchymal cells at certain stages of development. Both, the mesenchymal cells and the collagen fibrils adjacent to the posterior iris layer disappeared by the 10th day when the entire iris epithelium was completely pigmented. The possible origin of the collagen fibrils and the differentiation of the posterior iris epithelium are discussed.
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  • 41
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    Anatomy and embryology 151 (1977), S. 127-139 
    ISSN: 1432-0568
    Keywords: Cilia ; Human heart ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Primary 9+0 cilia have been found in the embryonic and the adult human heart. Proximally the cilia show the typical (+0 filament arrangement. Rearrangement of the filaments occur in their distal regions. The cilia are usually found in deep invaginations of the cell membrane, but can also be found in a superficial position. Close connections are frequently found between cilia and thin cytoplasmic extensions from neighbouring cells.
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  • 42
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    Anatomy and embryology 151 (1977), S. 97-108 
    ISSN: 1432-0568
    Keywords: Chick embryo ; Placode ; Electron microscopy ; Invagination ; Midbody
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The otic, the lens and the nasal placodes have been examined in chick embryos between stages 10 and 18 of Hamburger and Hamilton. At the stage when each placode first becomes visible conspicuous differences have been seen in the surface morphology between those cells which will invaginate and form the placode and those which will remain on the surface of the head, forming the epidermis. The differences become more pronounced with increasing development. The placode cells possess many surface projections whilst the epidermal cells do not. These differences in surface morphology are related to other differences which are visible in TEM sections, the placode cells being highly columnar and extending the full depth of the placode, whilst the epidermal cells are cuboidal or even squamous. This modification in cell shape of the placode cells is correlated with the presence of longitudinally orientated microtubules. The mechanism of invagination is discussed and evidence is presented which supports the idea that there is a migration of cells into the placode from one side. Such a phenomenon would help to explain the asymmetrical structure of the placode, including the presence of the overhanging lip.
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  • 43
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    Archives of dermatological research 260 (1977), S. 167-178 
    ISSN: 1432-069X
    Keywords: Electron microscopy ; Psoriasis pustulosa ; Spongiform pustule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Fünf Fälle von Psoriasis pustulosa wurden elektronenmikroskopisch untersucht. Die Hauptveränderungen im Corium bestanden in Capillardilatation mit intravasculären polymorphonukleären Leukocyten und Erythrocyten. Leukocyten traten durch die vasculären Spalten und Fenestrationen und wanderten durch das deutlich ödematöse Corium zur Epidermis. Lymphgefäße fanden sich ebenfalls. Histiocyten mit Langerhansgranula wurden in der Dermis und Epidermis beobachtet. Die morphologischen Veränderungen in der Epidermis waren abhängig von der Lokalisation und besonders stark ausgeprägt in der Nähe von voll entwickelten Pusteln in höheren Zellschichten. Früher beschriebene Befunde konnten bestätigt werden. Perinukleäre Cytolyse und andere Veränderungen in den Keratinocyten scheinen sekundär aufgrund des Ödems und der Ansammlung von Neutrophilen innerhalb der Epidermis zu entstehen. Immunologische Phänomene könnten hierfür verantwortlich sein.
    Notes: Summary Five cases of psoriasis pustulosa were examined by electron microscopy. The main features within the dermis were dilated capillaries filled with polymorphonuclear leukocytes and red cells. Neutrophils passed out of the vessels through the gaps and fenestrations and migrated towards the epidermis throughout the distinctly edematous corium. Lymphatic vessels could be found. Histiocytes containing Langerhans granules were observed in the dermis and epidermis. The morphological changes of the epidermis depented on the place examined and were most evident near fully developed pustules in the upper layers. The presence of previously described morphological findings could be confirmed. Perinuclear cytolysis and other changes in the keratinocytes, however, seem to be secondary, resulting from edema and accumulation of neutrophils within the epidermis. Immunological phenomenona may be responsible for the latter event.
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  • 44
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    Acta neuropathologica 37 (1977), S. 119-125 
    ISSN: 1432-0533
    Keywords: Amyloid polyneuropathy ; Electron microscopy ; Nerve fibers abnormalities ; Giant axons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two sporadic cases of amyloid polyneuropathy with clinical features corresponding to the Portuguese type of this disease were studied. Histological examination of sural nerve demonstrated a marked loss of myelinated and unmyelinated fibers in the case 1 due to axonal degeneration, high content of fibers with segmental demyelination and the occurrence of several enlarged axons filled with the 10 nm filaments (so-called giant axons). In the case 2 there was total loss of unmyelinated axons and myelinated fibers were nearly completely lacking. In the development of changes in the myelinated fibers their direct compression by amyloid deposits seems to play an important role. It leads to the appearance of both axonal degeneration and segmental demyelination. The latter seems to be due to local compression and it may involve many fibers. In the light of observations reported by other authors the mechanism of changes developing in unmyelinated fibers is explained by the presence of changes in the cells of posterior root ganglia, however the question whether some abnormalities seen in unmyelinated axons could not be related to the pressure exerted by amyloid deposits directly to these fibers, remains open.
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  • 45
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    Acta neuropathologica 37 (1977), S. 263-265 
    ISSN: 1432-0533
    Keywords: Progressive multifocal leukoencephalopathy ; Multiple sclerosis ; Demyelination ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Inclusions identical to those described in multiple sclerosis (MS) brain by Prineas (1975) have been seen by ultrastructural study of cerebral tissue in two elsewhere reported cases of Progressive Multifocal Leukoencephalopathy (PML). The meaning of these formations, which have been suggested to be related to a special process of demyelination in MS, is discussed in the light of the hypotheses concerning the demyelination mechanism in PML. Whatever might be their significance, these cytoplasmic non viral inclusions are not specific for MS.
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  • 46
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    Acta neuropathologica 39 (1977), S. 135-138 
    ISSN: 1432-0533
    Keywords: Clofibrate ; Striated muscle ; Histochemistry ; Electron microscopy ; Experimental animal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rats were given daily injections of 0.2 or 0.5 g/kg chlorophenoxyisobutyrate (clofibrate) for 9 to 46 days. Lower leg muscles were studied with light and electron microscopy. Daily treatment with 0.5 g/kg of the drug for 26–46 days caused myopathic changes.
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  • 47
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    Acta neuropathologica 37 (1977), S. 69-72 
    ISSN: 1432-0533
    Keywords: Neuropathy ; Fibroblast ; Endoneurial edema ; Peripheral nerve ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary “Focal mucoid degeneration” was found in a N. suralis biopsy of a 8 year old child, diagnosed clinically and electrophysiologically as progressive muscular atrophy Charcot-Marie-Tooth.
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  • 48
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    Acta neuropathologica 37 (1977), S. 127-135 
    ISSN: 1432-0533
    Keywords: Slow infection ; Viral encephalomyelitis ; Electron microscopy ; C-Type virus ; Immunopathology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of visna, a slowly progressive meningo-encephalomyelitis of sheep, was studied in animals sacrificed one month after intracerebral inoculation of visna virus. The major pathological changes, representative of those seen during the first year after infection, consist of inflammation and minor focal destructive lesions of grey and white matter. The inflammatory infiltrates, both subependymal and perivascular as well as of the choroid plexus, were composed mainly of lymphocytes and macrophages with varying numbers of plasma cells. The demyelination seen was of the secondary or Wallerian type. There was no evidence of primary demyelination. Visna virions were not seen in any of the CNS material studied. The ultrastructural findings are compatible with the view that lesions in visna may be induced by a cell-mediated immune response. However, changes characteristic of an autoimmune reaction to myelin antigens were not observed.
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  • 49
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    Keywords: Perexiline maleate ; Drug-induced neuropathy ; Nerve biopsy ; Muscle biopsy ; Skin biopsy ; Electron microscopy ; Lysosomes ; Segmental demyelination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The pathological findings in four nerves and muscles and in one skin biopsies from four patients treated with perhexiline maleate for angina pectoris are reported. In every case, a muscular denervation atrophy and a decrease in the large diameter myelinated fibers were observed. Only one case showed a decrease of the total number of myelinated fibers, on quantitative studies. The electron microscopic study of each nerve displayed findings consistent with a predominant schwannian degeneration, associated with a few onion bulbs formations and, in two cases, with a mild wallerian degeneration. The most striking finding consisted in the presence of polymorphous membrane-bound inclusions reminding the morphology of lysosomal complex lipids. These structures were very abundant in Schwann cells, but they were seen also in fibrocytes, endothelial and pericytic cells. Similar inclusions were present in the single muscle and skin biopsies studied by electron microscopy. In the muscle, they were seen in muscular cells as well as in endothelial and pericytic cells. In the skin, similar inclusions were observed in endothelial, smooth muscle and sweat gland cells. These inclusions were difficult to identifiy in one micron thick sections, emphazing the need of ultrastructural study for diagnostic purposes.
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  • 50
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    Keywords: Cytoplasmic tubular aggregates ; Electron microscopy ; Growth hormone cells ; Pituitary adenoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopy revealed the presence of cytoplasmic tubular aggregates in the capillary endothelium of a sparsely granulated growth hormone cell adenoma removed surgically from a 25-year-old female patient with acromegaly. To our knowledge, this is the second publication describing these structures in hypophysial growth hormone cell adenomas.
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  • 51
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    Acta neuropathologica 37 (1977), S. 95-100 
    ISSN: 1432-0533
    Keywords: Brain oedema ; Ouabain ; Na-K-ATPase ; Na-ion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ouabain, a specific inhibitor of active cation transport across cell membrane, was applied topically to brain surface of cats. The cerebral cortex to which 10−3 M ouabain was applied showed a spongy state, which was ultrastructurally revealed to be swelling of the neuronal cell processes, especially of dendrites. Astrocytes did not show swelling even in the most severely affected lesions. There was a marked increase in sodium with a slight increase of water in the most severely affected lesions. There was a marked increase in sodium with a slight increase of water in the cortex treated with 10−3 M ouabain. No evidence of increased vascular permeability was noted in the cortex, morphologically or biochemically. Electron microscopic cytochemistry to detect the sodium ion revealed that the increased sodium in the cortex accumulated in the swollen neuronal cell processes. It is speculated that neuronal rather than astrocytic elements might be highly dependent upon active cation transport, and that intracellular oedema in the brain tissue responsible for impairment of active cation transport might be related primarily to neuronal elements.
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  • 52
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    Acta neuropathologica 38 (1977), S. 39-43 
    ISSN: 1432-0533
    Keywords: Amyotrophic lateral sclerosis ; Muscle biopsy ; Target fibre ; Lamellar inclusions ; Transversal tubular system ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a muscle biopsy from a patient suffering about 2 years from an amyotrophic lateral sclerosis groups of atrophic fibres and target fibres were observed. By electron microscopic examination, amongst numerous parallel or spinal cisternae near the plasma membrane, single-membrane bound smooth tubular elements with a constant diameter of 200–300 Å occur in the central and intermediary zone of some target fibres. The connexion between these tubules and the terminal cisternae (triads) of the sarcoplasmic reticulum, suggest that this phenomenon seems to be a proliferation of the transversal-tubular system due to the partial denervation. Only a mechanical displacement of the T-tubules as a result of the destruction of the muscle fibres is not plausible, because the T-system volumetrically amounts only 0.3–0.5% of the muscle fibre.
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  • 53
    ISSN: 1432-0533
    Keywords: Human fetal muscle ; Electron microscopy ; Motor end-plate ; Extraocular muscles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The development of human extraocular muscles (EOM) was studied in a series of fetal specimens (12–24 weeks gestation). EOM were evaluated by enzyme histochemistry (EZ) (NADH and ATPase), by differential phase contrast microscopy (DPC) and electron microscopy (EM). In the early fetus (14 weeks), there was no clear-cut sub-division into fibre types. A uniform histochemical reaction was seen with NADH while ATPase showed light and dark myotubes. Myotubes contained large central nuclei, prominent eccentric nucleoli, abundant glycogen granules, free ribosomes, numerous mitochondria, and dense and looser bundles of myofilaments. Mesenchymal cells undergoing mitosis and fibroblasts with prominent stacks of rough endoplasmic reticulum were scattered within endomysium. Mast cells with well formed cytoplasmic granules were found as early as 18–24 weeks. The same specimens by DPC showed differentiation into at least 4 different fibre types at 12 weeks. All the intramuscular nerves at 12–16 weeks were composed of unmyelinated fibres. At 18 weeks, myelinated axons were present. Morphologically immature end-plates devoid of junctional folds were found at 12 weeks. The motor innervation of some EOM appears to be derived from more than one axon (multiple innervated fibres). At 18 weeks gestational age, differentiation into fibre types became apparent by enzyme histochemistry. These histochemical and morphological findings suggest that morphologically mature endplates are not prerequisites for differentiation into muscle fibre types.
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  • 54
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    Keywords: Resting microglia ; Silver impregnation ; Electron microscopy ; Hematogenous cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Vibratome sections of hippocampus of adult rabbits were stained by a modified Hortega's silver-carbonate method. Impregnated materials were examined by electron microscopy to decide fine-structural characteristics of the resting microglia. Comparing their characteristics with those of macrophages, we came to the following conclusions:(1) Impregnated resting microglia in the hippocampus of adult rabbits can be identified as cells having distinct fine structures. (2) Resting microglia are morphologically different from macrophages or their precursor cells, and therefore, seem not to be hematogenous cells sojourning in the normal brain parenchyma.
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  • 55
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    Acta neuropathologica 39 (1977), S. 177-180 
    ISSN: 1432-0533
    Keywords: Herpes simplex virus type II ; Organized CNS culture ; Cerebellar explants ; Electron microscopy ; Herpes infection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Organized cultures of newborn rat and hamster cerebellum were infected with herpes virus type II, after 7 and 14 days “in vitro”. 48 h after the infection, electron microscopic examination of the cultures showed that astrocytes contained numerous intranuclear and intracytoplasmic viral particles, while neurons remained apparently intact. The specificity of the infection for a given cell type is discussed.
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  • 56
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    Acta neuropathologica 39 (1977), S. 231-235 
    ISSN: 1432-0533
    Keywords: Actinomyces viscosus ; Epidural space ; Spinal cord ; Cat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a 3 year old female domestic cat a suppurative, granulomatous lesion of the tail and sacral area penetrated into the epidural space, causing paraplegia. A. viscosus was isolated from the inflammatory tissues. A comparative light and electron-microscopic study of the bacterial elements and the architecture of the granules (Drusen) show that the latter are in-vivo microcolonies of the agent.
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  • 57
    ISSN: 1432-0533
    Keywords: Metachromatic leukodystrophy ; Peripheral nerve ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural findings in nerve biopsies from two cases of late onset metachromatic leukodystrophy were compared with those in cases of late infantile and juvenile onset. Hypertrophic changes and regenerating clusters were more evident in the late onset cases, in which macrophages were less frequent, presumably reflecting the chronicity of the disorder in this form. Inclusions within Schwann cells and endoneurial macrophages were similar in all four cases. Myelin figures, in which the periodicity of major dense lines was 8 nm, were present in Schwann cells associated with myelinated axons. The electron lucent zones between the major dense lines were bisected by lines of lesser electron density. These inclusions were probably related to myelin breakdown. All other inclusions displayed a periodicity of 5.8 nm and consisted of zebra bodies, vacuoles containing irregularly orientated lamellar material and stacks of flattened discs. These inclusions represented the metachromatic sulphatide deposits. Occasional inclusion bodies were observed within axons.
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  • 58
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    Keywords: Spontaneously hypertensive rats ; Bilateral carotid occlusion ; Acute ischemic brain damage ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural study of cerebral infarcts in spontaneously hypertensive rats 1–5 h after bilateral carotid artery occlusion was performed. The alterations of the neocortex consisted of shrinkage of the neurons surrounded by swollen astrocytic processes. Distension of the rough endoplasmic reticulum of the neuronal cytoplasm appeared early, while changes of the mitochondria were slight. Though there appeared slight to moderate perivascular astrocytic swelling, endothelial swelling was rare and there was no severe narrowing of the capillary lumen. There were no filling defects of colloidal carbon injected to the blood vessels of the ischemic brains. Ischemic neuronal alterations were proved to develop in the absence of severe morphological changes of the microvasculature in the developing cerebral infarcts in the present experimental model.
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  • 59
    ISSN: 1432-0533
    Keywords: Poxvirus group ; Vaccinia virus, neurovirulent ; Neurovaccinia strains ; Meningoencephalitis, experimental ; Virus morphogenesis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Adult NMRI mice were inoculated intracerebrally with 1.5–5×102 pfu of the “neurovirulent” strain Ma1 of vaccinia virus. The animals usually became diseased on day 3 and died on day 5 or 6 p.i. Infectivity assay studies on the mouse brains yielded a steeply rising viral titer comparable with that exhibited by several other so-called neurovaccinia strains after intracerebral inoculation. Histological studies revealed a patchy leptomeningitis most apparent over the basal brain surface. Mononuclear elements of varied size were the most common infiltrate cells in the meningitic lesions. These often showed a pronounced hemorrhagic and necrotizing character. In some places, the cellular infiltrates within the subarachnoid space extended along the perforating vessels into the superficial cerebral cortex. By electron microscopy, all essential stages of virus morphogenesis including the discharge of mature virions could be seen in numerous mononuclear phagocytes and adventitial cells. In contrast to this, no unequivocal neuroectodermal cell showed morphologic evidence of productive viral infection. Likewise, no endothelia or vascular myocytes were encountered which contained newly formed virus particles. However, alterations of the walls of blood vessels and signs of disturbed vascular permeability were a frequent finding in the meningeal foci of inflammation as well as in and around the track left by the inoculating needle. Another ultrastructural feature of the meningitic lesions was the widespread occurrence of degenerating or disintegrating infiltrate cells both infected and uninfected ones. The virologic and morphologic findings observed in this model of experimental vaccinia virus meningo-encephalitis are discussed with regard to data previously published by other authors. The propensity of strain Ma1 of vaccinia virus (and most probably of other so-called neurovaccinia strains) for replication in mesenchymal cells in particularly emphasized.
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    Acta neuropathologica 40 (1977), S. 73-77 
    ISSN: 1432-0533
    Keywords: Transplacental carcinogenesis ; Ethylnitrosourea ; Schwannomas ; Free cholesterol ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Malignant schwannomas of the trigeminal nerves were induced transplacentally by a single intravenous injection of 30 mg of N-ethyl-N-nitrosourea per kg of body weight into pregnant BD-IX rats on the 15th day of gestation. These neoplasms consisted of a pleomorphic population of Schwann cells and occasional fibroblasts. In order to preserve sterols the tumours were fixed in a digitonin-containing aldehyde solution. The electron microscope investigation of the tissues so treated revealed various structures: lamellar, tubular and complex formations were all observed. In addition, the unit membranes, including those of various cytoplasmic organelles, showed areas of increased contrast. The abundance of these fine structural configurations indicated the high sterol content of ethyl-nitrosourea-induced schwannomas.
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    Acta neuropathologica 38 (1977), S. 187-194 
    ISSN: 1432-0533
    Keywords: Fabry's disease ; Muscle biopsy ; Nerve biopsy ; Electron microscopy ; Lamellar bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A study of a muscle biopsy has provided evidence of storage involvement of the skeletal muscle fibres in Fabry's disease. In the endothelial cells of the capillaries, the inclusions were more abundant and pleomorphic. Muscle satellite cells were spared. In the sensory nerve biopsy, the perineurial and endothelial cells contained lamellar bodies, but not the Schwann cells. There was a slight reduction of the number of the small myelinated fibres and of the unmyelinated fibres. An electron microscopic study of a muscle biopsy can be helpful in the diagnosis of the disease. The physiopathology of the pain attacks is still a matter for discussion.
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  • 62
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    Acta neuropathologica 40 (1977), S. 163-169 
    ISSN: 1432-0533
    Keywords: Leucodystrophy ; Myelin ; Dog ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A recently recognised progressive disorder of central myelin in Dalmatian dogs is described. The disease is probably transmitted by autosomal recessive inheritance. The symptoms started at the age of 3–6 months and were dominated by visual deficiency and/or progressive locomotive abnormalities. Pathologically, the most consistent lesions were found bilaterally in the region of the centrum semiovale. The optic nerves were also frequently affected, the basal ganglia and spinal cord were affected infrequently. The main lesions were confined to myelin, while axons and nerve cells were spared, particularly in the early stages of the lesions. Numberous phagocytes were observed which contained engulfed myelin and other lipid breakdown products. Ultrastructurally and histochemically the disease differs from previusly described types of leucodystrophy.
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    Acta neuropathologica 40 (1977), S. 157-161 
    ISSN: 1432-0533
    Keywords: Tuberous sclerosis ; Electron microscopy ; Astrocytes ; Microvilli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A sporadic case of tuberous sclerosis in a stillborn infant is reported. The death at the 31st week of gestation was presumably due to the development of enormous rhabdomyomas of the heart. The typical cerebral lesions were fully developed as in patients deceased later in life. The atypical cells found in the cortical tubers demonstrated ultrastructural features of reactive astrocytes. Moreover, they showed innumerable microvillilike projections on their surface and junctional complexes, mostly of the zonula adhaerens type, reminiscent of ependymocytes. The significance of such glio-epithelial cellular features is discussed.
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  • 64
    ISSN: 1432-0533
    Keywords: Disulfiram psychosis ; Electron microscopy ; Synaptic changes ; Dopamine-β-hydroxylase ; Histotoxic anoxia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Following chronic administration of disulfiram to rats, changes of the brain were examined electron-microscopically. Pathological findings were observed in the nerve cells of the cerebral cortex and hypothalamus at later stage, and synaptic changes in the hypothalamus from initial stage. On the other hand, changes of myelinated fibers, neuroglias and capillaries were very slight. It was considered that neurons were affected more predominantly than other neuronal elements by the cytotoxic action of the drug, and that the synaptic changes of the hypothalamus might reveal chronic disturbance of noradrenergic transmission by inhibition of dopamine-β-hydroxylase. These ultrastructural findings might relate to the pathogenic mechanism of the disulfiram psychosis.
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    Acta neuropathologica 39 (1977), S. 173-175 
    ISSN: 1432-0533
    Keywords: Parkinson's disease ; Lewy body ; Dense core vesicles ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a case of Lewy body disease incidentally found at autopsy, numerous dense core vesicles, 80–200 nm in diameter, were seen in the neuronal perikarya of the locus caeruleus. They were particularly numerous in the vicinity of the Lewy bodies. The change seems to occur at the early stage of Lewy body production and may represent an additional morphologic clue to abnormal catecholamine metabolism in Parkinson's disease.
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  • 66
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    Acta neuropathologica 37 (1977), S. 65-68 
    ISSN: 1432-0533
    Keywords: Electron microscopy ; Neuropathology ; Down's syndrome ; Human cerebral cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a quantitative electronmicroscopic study, autopsy samples from the frontal and temporal lobes of two severely defective mongoloid brains were examined for the presence of abnormalities in the ultrastructure of the cerebral cortex. Particular attention was paid to the occurrence of atypical neuronal and glial inclusions similar to those which occur in small numbers (1 in 5000 µ2 of cortex) in neurologically normal brain (Rees, 1975). An area of 3.6×105 µ2 of cortex was examined from each brain. Within the cortical parenchyma, there was no gliosis, neuronal death or areas of degeneration. Atypical neuronal and glial inclusions were observed in both of the retarded brains, but they did not occur in substantially different numbers from normal brains. There were no inclusions or structural abnormalities peculiar to the retarded brains. Thus, in these two defective brains, it has not been possible to demonstrate any specific abnormalities in the ultrastructure of the cortex.
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  • 67
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    Keywords: Lymphocyte ; Juvenile amaurotic idiocy ; Ceroid lipofuscinosis ; Vacuolar contents ; Electron microscopy ; Sural nerve ; Muscle ; Rectum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Lymphocytes of the peripheral blood of 31 patients with juvenile amaurotic idiocy (juvenile form of ceroid lipofuscinosis) were examined with the electron microscope. In all cases, intracytoplasmic clear vacuoles were present, containing round hollow, fingerprint and highly electron dense structures. The combination of these structures, not necessarily in one and the same vacuole, was considered to be highly indicative for the diagnosis of juvenile amaurotic idiocy. In addition to these three structures, parallel tubular inclusion bodies, rectilinear profiles and rodshaped structures were found but in a number of the cases. The parallel tubular inclusion bodies were not regarded as having any diagnostic significance.
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  • 68
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    Acta neuropathologica 37 (1977), S. 213-217 
    ISSN: 1432-0533
    Keywords: Peripheral neuropathy ; Giant axons ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An 8-year-old boy with a slowly progressive motor neuropathy is described. The first signs appeared at the age of 3 years. Histological examination of the sural nerve showed the presence of numerous segmental axonal swellings and features of demyelination as well as remyelination. These enlargements were filled with irregularly orientated 10 nm filaments. The case resembled the previously described cases of giant axonal neuropathy but differed from them in absence of kinky hair.
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  • 69
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    Calcified tissue international 23 (1977), S. 215-223 
    ISSN: 1432-0827
    Keywords: Amorphous mineral ; Bone ; Electron microscopy ; Ultracryotomy ; Ultramicro-incineration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The fine structure of the extracellular phase of avian medullary bone and embryonic chick femur was examined in thin sections prepared by ultracryotomy and ultramicroincineration. Since contact with solutions was completely avoided, little or no loss or dislocation of mineral constituents could occur. Amorphous bone mineral (ABM) was present in two forms: as 15–30 nm spheres and as a structure-free haze. Removal of all organic material by low temperature ashing left the ABM intact. Crystals were usually associated with the ABM. In newly ossifying regions clusters or nodules of randomly oriented crystals and ABM appeared to coalesce when they reached approximately 1 μm in diameter. In highly calcified regions crystals appeared to be oriented along collagen fibers. ABM did not appear to be associated with collagen. Unmineralized collagen was visible in osteoid after staining with dry OsO4 vapor and it appeared to be diverted around nodules. Structures which resembled matrix vesicles were present. Selected area electron diffraction patterns indicated the presence of hydroxyapatite.
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  • 70
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    Calcified tissue international 24 (1977), S. 191-197 
    ISSN: 1432-0827
    Keywords: Amelogenesis imperfecta ; Hypocalcification ; Hypoplasia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary An ultrastructural study of teeth with amelogenesis imperfecta revelaed various aspects of microcavities in the enamel surface, which ranged from isolated imprints of ameloblasts corresponding to the mildest lesions at the end of amelogenesis, to pits caused by the death of 20 to 30 ameloblasts at the beginning of amelogenesis. Abnormalities in the shape of the prisms can be observed. Further, crystals are distributed randomly within a prism or at the junction of 2 contiguous prisms while intercrystalline spaces are widened, indicating in various places the lack of a preferred orientation of the crystals. In amelogenesis imperfecta, two different crystalline periods are found: 1 of about 250 Å, the other of about 500 Å and over. The fact that amorphous areas are found among the crystals of enamel may be related to different stages of crystallization. However, it was not possible to find any lattice defect.
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  • 71
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    Calcified tissue international 24 (1977), S. 239-242 
    ISSN: 1432-0827
    Keywords: Cementum ; Lysis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Examination of microradiographs from the deciduous teeth of pigs revealed large lacunae or radiolucent zones close to the cemento-dentinal junction. Electron microscopic studies of the ground sections showed areas or irregularly shaped zones devoid of mineral and filled with collagen fibers. In the wide unmineralized zones, spherical clusters of crystallites were noted. Several cementum lacunae bordered by a broad rim of unmineralized collagen fibers were noted and some lacunae also contained zones of a moderately electron dense material. This material did not yield a diffraction pattern, while the mineralized part of the cementum gave the diffraction pattern typical of hydroxyapatite.
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  • 72
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    Journal of molecular medicine 55 (1977), S. 1137-1147 
    ISSN: 1432-1440
    Keywords: Edema ; Capillary permeability ; Pericardial effusion ; Microcirculation ; Electron microscopy ; Ödem ; Kapillarpermeabilität ; Perikarderguß ; Mikrozirkulation ; Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 2 Patientinnen hatten neben dem Krankheitsbild der idiopathischen Ödeme Höhlenergüsse insbesondere des Perikards. In dem einen Fall erforderte der große Perikarderguß schließlich die Perikardresektion, im anderen Fall führte Spironolacton-Dauerbehandlung zur weitgehenden Normalisieriung. Der relativ hohe Eiweißgehalt von Ödem (25 und 12 g/l) und Perikarderguß (55–61 und 48 g/l) und der vergrößerte Verteilungsraum für markiertes Eiweiß sprechen für vermehrte Permeabilität von kleinen Gefäßen und Grenzflächen für Eiweiß. Das Blutvolumen war niedrig normal bzw. erniedrigt. Elektronenoptisch fanden sich an den Hautgefäßen abnorme endotheliale Protuberanzen und große intercelluläre Lücken (Gaps) und an den Muskelgefäßen Befunde, die für einen gesteigerten cytopemptischen Transport sprechen. Die elektronenmikroskopischen Befunde der beiden Patientinnen zeigen keine prinzipiellen Unterschiede; sie stellen offenbar das morphologische Substrat gesteigerter Eiweißpermeabilität der Gefäße und der Bildung relativ eiweißreicher Ödeme dar. Damit sind morphologische Veränderungen bei Menschen mit idiopathischen Ödemen nachgewiesen, wie sie bisher nur in Tierversuchen mit experimentell erzeugten Ödemen beobachtet wurden.
    Notes: Summary Clinical and electron microscopic studies of two female patients are reported who, in addition to the symptoms and signs of idiopathic edema, had pericardial (and pleural) effusions. In one patient pericardiectomy had to be performed, in the other patient pharmacotherapy with spironolactone was effective. In these patients the protein-concentrations of edema fluid (25 and 12 g/l) and pericardial fluid (55–61 and 48 g/l) were relatively high; the distribution space of labelled protein was increased; blood volumes were low-normal or decreased. Electronmicroscopy of the microvasculature showed identical alterations in both cases. In the cutaneous vessels the endothelium developed numerous abnormal cytoplasmic processes and intercellular “gaps”. In the capillaries of skeletal muscle our findings indicate an increase in vesicular transport. We suggest the electron microscopic alterations to be the morphologic correlate for the increased transport and extravascular accumulation of protein. Changes as they are described here in humans with idiopathic edema have been documented before in animals with experimental edema.
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  • 73
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    Journal of neurology 215 (1977), S. 81-90 
    ISSN: 1432-1459
    Keywords: Spinal nerve root ; Cauda equina ; Transsection and suture ; Regeneration ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Regeneration in dorsalen und ventralen Nervenwurzeln der Cauda equina nach Durchtrennung und Naht am Schwein wurde nach dreimonatiger Überlebenszeit untersucht. Obwohl keine detaillierten quantitativen Analysen durchgeführt wurden, konnte eindeutig festgestellt werden, daß die Regeneration in motorischen Wurzeln ausgiebiger was als in sensiblen Wurzeln. In den regenerierten Wurzeln wurde eine Zunahme von Histiozyten, Fibroblasten und Collagen sowie eine Verdickung der Wurzelhüllen beobachtet. In regenerierten dorsalen Wurzeln fanden sich heterotope, vom Myelon ausgewachsene Gliabündel.
    Notes: Summary The regeneration of nerve fibres in pigs was studied three months after transsection and end-to-end suture of the dorsal and ventral spinal nerve roots L 5 and S 1. Although no detailed quantitative analysis was performed, it was clearly evident that regeneration in motor roots is significantly more efficacious than in sensory roots. Probably as a reaction to Wallerian degeneration, an increase of histiocytes, fibroblasts and collagen fibrils, as well as a thickening of the sheaths was observed in the transsected and sutured roots. Heterotopic glial bundles were found in the regenerated dorsal roots.
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  • 74
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    Journal of neurology 215 (1977), S. 81-90 
    ISSN: 1432-1459
    Keywords: Spinal nerve root ; Cauda equina ; Transsection and suture ; Regeneration ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Regeneration in dorsalen und ventralen Nervenwurzeln der Cauda equina nach Durchtrennung und Naht am Schwein wurde nach dreimonatiger Überlebenszeit untersucht. Obwohl keine detaillierten quantitativen Analysen durchgeführt wurden, konnte eindeutig festgestellt werden, daß die Regeneration in motorischen Wurzeln ausgiebiger was als in sensiblen Wurzeln. In den regenerierten Wurzeln wurde eine Zunahme von Histiozyten, Fibroblasten und Collagen sowie eine Verdickung der Wurzelhüllen beobachtet. In regenerierten dorsalen Wurzeln fanden sich heterotope, vom Myelon ausgewachsene Gliabündel.
    Notes: Summary The regeneration of nerve fibres in pigs was studied three months after transsection and end-to-end suture of the dorsal and ventral spinal nerve roots L 5 and S 1. Although no detailed quantitative analysis was performed, it was clearly evident that regeneration in motor roots is significantly more efficacious than in sensory roots. Probably as a reaction to Wallerian degeneration, an increase of histiocytes, fibroblasts and collagen fibrils, as well as a thickening of the sheaths was observed in the transsected and sutured roots. Heterotopic glial bundles were found in the regenerated dorsal roots.
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  • 75
    ISSN: 1432-1459
    Keywords: SMON ; Muscle biopsy ; Electron microscopy ; Neuromuscular junction ; Paracrystalline inclusions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ein 46jähriger Mann, welcher über lange Zeit hohe Dosen von Clioquinol einnahm, entwickelte recht plötzlich charakteristische neurologische Ausfälle, entsprechend einer subakuten myelooptischen Neuropathie (SMON). Bei der elektronenoptischen Untersuchung einer Muskelbiopsie, die 5 Monate nach Beginn der Erkrankung entnommen worden war, zeigten sich ausgeprägte degenerative Veränderungen der präsynaptischen Nervenendigungen und vereinzelte parakristalline Einschlüsse in der Endplattenregion, die einmalig erscheinen. Letzteres könnte das morphologische Substrat der toxischen Substanz darstellen, die für den SMON verantwortlich gemacht wird.
    Notes: Summary A man, aged 46, who had been taking Clioquinol in high doses for a long period, developed a characteristic neurological syndrome of subacute myelo-optic neuropathy rather abruptly. Electron microscopical examination of the muscle biopsy, obtained five months after the onset of the disease, revealed severe degenerative changes of the presynaptic nerve endings and some unique paracrystalline inclusions in the sole plate region. The latter may represent the morphological expression of the toxic agent which is held responsible for the subacute myelo-optic neuropathy.
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  • 76
    ISSN: 1432-1459
    Keywords: SMON ; Muscle biopsy ; Electron microscopy ; Neuromuscular junction ; Paracrystalline inclusions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ein 46jähriger Mann, welcher über lange Zeit hohe Dosen von Clioquinol einnahm, entwickelte recht plötzlich charakteristische neurologische Ausfälle, entsprechend einer subakuten myelooptischen Neuropathie (SMON). Bei der elektronenoptischen Untersuchung einer Muskelbiopsie, die 5 Monate nach Beginn der Erkrankung entnommen worden war, zeigten sich ausgeprägte degenerative Veränderungen der präsynaptischen Nervenendigungen und vereinzelte parakristalline Einschlüsse in der Endplattenregion, die einmalig erscheinen. Letzteres könnte das morphologische Substrat der toxischen Substanz darstellen, die für den SMON verantwortlich gemacht wird.
    Notes: Summary A man, aged 46, who had been taking Clioquinol in high doses for a long period, developed a characteristic neurological syndrome of subacute myelo-optic neuropathy rather abruptly. Electron microscopical examination of the muscle biopsy, obtained five months after the onset of the disease, revealed severe degenerative changes of the presynaptic nerve endings and some unique paracrystalline inclusions in the sole plate region. The latter may represent the morphological expression of the toxic agent which is held responsible for the subacute myelo-optic neuropathy.
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  • 77
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    Journal of neurology 215 (1977), S. 103-114 
    ISSN: 1432-1459
    Keywords: Hypothyroidism ; Peripheral neuropathy ; Nerve biopsy ; Electron microscopy ; Renaut bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es werden die klinischen Daten und Nervenbiopsiebefunde von 4 hypothyreotischen Patienten, die Symptome einer diffusen peripheren Neuropathie aufwiesen, dargestellt. Klinisch-neurologisch bestanden sensiblen Reizzeichen von scherzhaftem Charakter, eine symmetrische, distale Sensibilitätsminderung mit Ataxie und eine Abschwächung der Muskeleigenreflexe mit Verlust der Achillessehnenreflexe. Bei einem Patienten war die periphere Neuropathie Leitsymptom der zugrunde liegenden metabolischen Erkrankung. Als Substrat dieser Ausfälle fand sich bei der licht- und elektronenmikroskopischen Untersuchung der N. suralis-Biopsien eine deutliche Verminderung der Markfasern, besonders die großkalibrigen, dickbemarkten Axone betreffend. Die Histogramme zeigten entsprechend ein pathologisches unimodales Faserspektrum. Dystrophische und degenerative Veränderungen an Axonen aller Faserklassen und das Vorkommen sogenannter „Regenerationsgruppen“ kleiner, dünnbemarkter Fasern deuten darauf hin, daß der Neuropathie bei diesen hypothyreotischen Patienten in pathogenetischer Hinsicht in erster Linie eine neuroaxonale Degeneration mit unvollständiger Regeneration zugrunde liegt.
    Notes: Summary Clinical and sural nerve biopsy findings are described in four hypothyroid patients with manifestations of a diffuse peripheral neuropathy. Clinical examination revealed distal sensory inpairment, complaints of burning and lancinating extremity pains, ataxia and a decrease of deep tendon reflexes with total ankle jerk loss. In one patient, signs of the peripheral neuropathy comprised the leading symptomatology of the underlying metabolic disorder. Light and electron microscopic investigations of the sural nerve biopsies revealed a marked reduction of myelinated fibers, affecting mainly the large myelinated axons. The histograms showed a pathological unimodal spectrum of myelinated fiber diameters. Dystrophic and degenerative changes in axons of all fiber classes and the presence of clusters of thinly myelinated small fibers suggest that neuroaxonal degeneration and incomplete regeneration may represent the major pathogenetic mechanism of the neuropathy in these hypothyroid patients.
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  • 78
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    Journal of neurology 215 (1977), S. 103-114 
    ISSN: 1432-1459
    Keywords: Hypothyroidism ; Peripheral neuropathy ; Nerve biopsy ; Electron microscopy ; Renaut bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es werden die klinischen Daten und Nervenbiopsiebefunde von 4 hypothyreotischen Patienten, die Symptome einer diffusen peripheren Neuropathie aufwiesen, dargestellt. Klinisch-neurologisch bestanden sensiblen Reizzeichen von scherzhaftem Charakter, eine symmetrische, distale Sensibilitätsminderung mit Ataxie und eine Abschwächung der Muskeleigenreflexe mit Verlust der Achillessehnenreflexe. Bei einem Patienten war die periphere Neuropathie Leitsymptom der zugrunde liegenden metabolischen Erkrankung. Als Substrat dieser Ausfälle fand sich bei der licht- und elektronenmikroskopischen Untersuchung der N. suralis-Biopsien eine deutliche Verminderung der Markfasern, besonders die großkalibrigen, dickbemarkten Axone betreffend. Die Histogramme zeigten entsprechend ein pathologisches unimodales Faserspektrum. Dystrophische und degenerative Veränderungen an Axonen aller Faserklassen und das Vorkommen sogenannter „Regenerationsgruppen“ kleiner, dünnbemarkter Fasern deuten darauf hin, daß der Neuropathie bei diesen hypothyreotischen Patienten in pathogenetischer Hinsicht in erster Linie eine neuroaxonale Degeneration mit unvollständiger Regeneration zugrunde liegt.
    Notes: Summary Clinical and sural nerve biopsy findings are described in four hypothyroid patients with manifestations of a diffuse peripheral neuropathy. Clinical examination revealed distal sensory inpairment, complaints of burning and lancinating extremity pains, ataxia and a decrease of deep tendon reflexes with total ankle jerk loss. In one patient, signs of the peripheral neuropathy comprised the leading symptomatology of the underlying metabolic disorder. Light and electron microscopic investigations of the sural nerve biopsies revealed a marked reduction of myelinated fibers, affecting mainly the large myelinated axons. The histograms showed a pathological unimodal spectrum of myelinated fiber diameters. Dystrophic and degenerative changes in axons of all fiber classes and the presence of clusters of thinly myelinated small fibers suggest that neuroaxonal degeneration and incomplete regeneration may represent the major pathogenetic mechanism of the neuropathy in these hypothyroid patients.
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  • 79
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    Archives of microbiology 113 (1977), S. 197-204 
    ISSN: 1432-072X
    Keywords: Gliding bacterium ; Simonsiella ; Oral cavity ; Electron microscopy ; Morphology ; Dorsal-ventral differentiation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The morphology and ultrastructure of the aerobic, Gram-negative multicellular-filamentous bacteria of the genus Simonsiella were investigated by scanning and transmission electron microscopy. The flat, ribbon-shaped, multicellular filaments show dorsal-ventral differentiation with respect to their orientations to solid substrata. The dorsal surface, orientated away from the substrate, is convex and possesses an unstructured capsule. The ventral surface, on which the organisms adhere and glide, is concave and has an extracellular layer with fibrils extending at right angles from the cell wall. The cytoplasm in the ventral region contains a proliferation of intracytoplasmic membranes and few ribosomes in comparison to the cytoplasm in other parts of the cell. Centripetal cell wall formation is asymmetrical and commences preferentially in the ventral region. Quantitative differences in morphology and cytology exist among selected Simonsiella strains. Functional aspects of this dorsalventral differentiation are discussed with respect to the colonization and adherence of Simonsiella to mucosal squamous epithelial cells in its ecological habitat, the oral cavities of warm-blooded vertebrates.
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  • 80
    ISSN: 1432-072X
    Keywords: Acetobacterium woodii ; Hydrogen-oxidizing acetate-forming anaerobe ; Fine structure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Acetobacterium woodii is a Gram-positive anaerobic nonsporeforming bacterium able to grow on H2 and CO2 as sole sources of energy. The product of fermentation is acetic acid. Fine structural analysis showed rod-shaped flagellated cells, and coccoid cells without flagella arranged predominantly in pairs and chains. The cell wall was found to be composed of three layers. The cell surface exhibited a periodic array of particles consisting of subunits. The cytoplasmic membrane showed particles either either in random distribution or in a hexagonal pattern. Intracytoplasmic membranes were rarely observed, whereas inclusion bodies of varying shapes, predominantly in an uncommon disc-shape, could frequently be observed. Their content was dissolved in ultrathin sections indicating hydrophobic nature.
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  • 81
    ISSN: 1432-072X
    Keywords: Defective lysogeny ; Alcaligenes eutrophus ; Simultaneous isolation technique ; Temperate bacteriophages ; Pseudomonas pseudoflava ; Biological characterization ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Widespread defective lysogeny was detected in Alcaligenes eutrophus by electron microscopic analysis of cultures. Mitomycin C treatment of the cultures resulted in the production of defective (inco-) particles. Polysheaths were produced both with and without induction. With the simultaneous isolation technique six phages were isolated for hydrogen-oxidizing strains of the new species Pseudomonas pseudoflava. The phages were able to replicate under autotrophic conditions and were found to have a very restricted host range. Electron microscopic analysis allowed classification into two structural groups. Group I contained phages with contractile tails; group II contained phages with flexible, noncontractile tails. All but one (gb) of the new phages were shown to be temperate by isolation of lysogens and induction with mitomycin C.
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  • 82
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    Archives of microbiology 112 (1977), S. 207-218 
    ISSN: 1432-072X
    Keywords: Cryptophyceae ; Algae ; Hemiselmis rufescens ; Chroomonas ; Cryptomonas ; Mitochondrial complex ; Cristae ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The unitary nature of the mitochondrion and the characteristic flattened finger-like morphology of the cristae were demonstrated in the Cryptophyceae. Hemiselmis rufescens contained an unbranched vermi-form mitochondrion in contrast to the variously branched complex, comprising an interconnected peripheral and central reticulum, in Chroomonas sp. and strains of Cryptomonas. The systematic value of the shape and distribution of the mitochondria in the examined genera was suggested.
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  • 83
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    Archives of microbiology 115 (1977), S. 185-198 
    ISSN: 1432-072X
    Keywords: Synechococcus lividus ; Cyanobacteria ; Carbon dioxide ; Electron microscopy ; Bleaching-regreening
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of carbon dioxide on pigment and membrane content in Synechococcus lividus was studied by depriving cells of CO2 and examining cell populations biochemically and by electron microscopy. After 120 h of CO2 deprivation, S. lividus lost all detectable chlorophyll a and C-phycocyanin. Such bleached cultures were “mustard yellow”, the result of approximately 1.8 times more carotenoid per cell than green control cultures. Although cells from beached cultures appeared morphologically identical to control green cells when examined by light microscopy, electron microscopic examination revealed them to be devoid of detectable thylakoid membrane. Thylakoid membrane could not be recovered by physical isolation or revealed by freeze etching of bleached S. lividus. In addition, inclusion bodies characteristically found in S. lividus were also absent. Reintroduction of CO2 into bleached cultures resulted in a rapid resynthesis of both chlorophyll a and C-phycocyanin. Electron microscopic examination of these regreening cultures revealed that thylakoid membrane was also rapidly resynthesized. Growth of regreened cultures did not occur until there was the synthesis of a full complement of chlorophyll a, C-phycocyanin, and thylakoid membrane. A time course study of the cytological events occurring during bleaching and regreening is presented.
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  • 84
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    Virchows Archiv 372 (1977), S. 287-297 
    ISSN: 1432-2307
    Keywords: Stomach ; Lipid islands ; Smooth muscle cells ; Foam cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Foam cells in lipid islands of the stomach can develop from both histiocytes and smooth muscle cells. With increasing storage of lipid vacuoles in smooth muscle cells, loosening of the myofilament arrangement and decrease of the dense areas subjacent to the plasma membrane occurs. Endoplasmic reticulum and the cisternae of the Golgi-apparatus dilate, the cell organelles increase initially and the basement membrane of the smooth muscle cells is fragmentarily formed. Only in incompletely formed foam cells can the origin from smooth muscle cells be recognised, in their final state their histiogenesis is seldom apparent.
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  • 85
    ISSN: 1432-2307
    Keywords: Myeloproliferative disorder ; Megakaryocytic-granulocytic myelosis ; Granulocyte lineage ; Bone marrow biopsy ; Freeze-fracture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In 5 patients with chronic megakaryocytic-granulocytic myelosis (CMGM) bone marrow specimens were studied by electron microscopy to investigate possible abnormalities of the granulocytic cell lineage. Thin sections were compared with freeze-fracture replicas to elucidate further aspects of leucocyte cytology. The atypia exhibited in these cells (eosinophils, basophils and neutrophil granulocytes) consisted mostly of a disorganization of granulopoiesis with hyper- and hypogranulation, a pathological increase in the number of nuclear blebs and a maturation asynchrony sometimes leading to Pelger-like cell forms. Moreover, a presumptive stem cell was demonstrated in the erythopoietic and granulocytic cell lines resembling CFU cells. In conclusion, granulopoiesis in CMGM exhibited abnormalities as generally observed in chronic myelogenous leukaemia. When considered with our previous finding of malignancy in megakaryopoiesis, CMGM has to be classified as a myelosis of mixed cellularity.
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  • 86
    ISSN: 1432-2307
    Keywords: Vinylchloride-disease ; Splenomegaly ; Electron microscopy ; Enzyme histochemistry ; Morphometrics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Durch histometrische, enzymhistochemische und elektronenmikroskopische Untersuchungen konnte nachgewiesen werden, da\ die pathologischen MilzverÄnderungen bei der Vinylchlorid-Krankheit nicht durch hepatisch bedingte Pfortaderdruckerhöhung verursacht werden, sondern auf einer Gewebsalteration durch das Vinylchlorid oder dessen Metabolite beruhen. Dabei sind vor allem die faserbildenden Zellen der Milz beteiligt. Faserassoziierte Reticulumzellen in der roten Pulpa und fibroblastische Reticulumzellen in der wei\en Pulpa werden zu übermÄ\iger Bindegewebsneubildung stimuliert. Hierdurch kommt es in der roten Pulpa zur bindegewebigen Verödung der FiltrationsrÄume mit einer Reduzierung der Pulpastrangmakrophagen und in der wei\en Pulpa zu einer Vernarbung der periarteriellen Lymphscheiden. Die Folgen dieser Fibrosierungsprozesse sind charakteristische VerÄnderungen in der quantitativen Zusammensetzung der Gewebskomponenten, die sich deutlich von denjenigen in Milzen bei Lebercirrhose und Milzvenenthrombose unterscheiden.
    Notes: Summary By means of histometric, enzyme histochemical, and electron microscopic investigations it was demonstrated that the pathological changes in the spleen in vinylchloride-disease are primary. Fibroblastic cells are the only specific splenic cells involved. Fibre-associated reticulum cells of the red pulp and fibroblastic reticulum cells in white pulp are stimulated to produce excessive amounts of the extracellular elements of connective tissue, especially collagen fibrils. The newly formed connective tissue causes obliteration of extracellular blood channels in the red pulp and thus a reduction in the number of pulp-cord macrophages, and scarring of the periarterial lymphatic sheaths. The results of this fibrosing process are characteristic quantitative changes in the splenic histologic structures. These changes are different from those structural alterations occuring in spleens following extrasplenic hemodynamic changes, such as thrombosis of the splenic veins or cirrhosis of the liver.
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  • 87
    ISSN: 1432-2307
    Keywords: Thyroid gland ; Familial medullary carcinoma ; Morphogenesis ; Electron microscopy ; Cytochemistry of C-cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Six cases of familial medullary thyroid carcinoma (MTC) were investigated by light and electron microscopy as well as by ultracytochemical methods. Light microscopic examination revealed multifocal C-cell proliferation in 5 subjects. These cells were mostly limited to thyroid follicles, but occasionally extended across the follicular capsule forming microscopic MTC. Electron microscopic examination showed that, in some follicles, the proliferating C-cells were still covered by a continuous layer of follicular cells, whereas in others the proliferation extended to the follicular center. C-cells were in direct contact with the colloid, and ultramicroinvasion of the follicular capsule was detected. These observations are consistent with the hypothesis that familial MTC seems to begin as multifocal C-cell proliferation, limited at first to thyroid follicles, between the capsule and the follicular epithelium. Later, the proliferation extends to the follicular center, and C-cells come in contact with the colloid, at which time an in situ carcinoma stage is reached. Some neoplastic cells invade the follicular capsule and, finally, multiple MTC appear and eventually conglomerate. Generally, there were no constant morphologic criteria for a dysplasia or neoplasia among the proliferating C-cells limited to thyroid follicles, when compared with normal or even malignant C-cells. For these reasons, a hyperplastic or dysplastic process preceding MTC cannot be clearly distinguished from a neoplastic process. Our study, however, shows that a light microscopic, apparently hyperplastic process may be a malignant one. Amyloid was present in the more voluminous MTC, associated with tumor cell necrosis, but it was not evident in small MTC and within the foci of C-cell proliferation. Ultracytochemical techniques revealed that the secretory granules of normal, proliferating and neoplastic C-cells contained polysaccharides and/or glycoproteins.
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  • 88
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    Virchows Archiv 374 (1977), S. 275-284 
    ISSN: 1432-2307
    Keywords: Signet-ring cell ; Scirrhous carcinoma ; Gastric carcinoma ; Electron microscopy ; Stomach cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The signet-ring cells seen in gastric carcinoma of the diffuse type were studied by light and electron microscopy. A classification of these cells into Types A, B and C was developed, based on intracellular mucous granules, nuclei and organelles, and by reactions to PAS and Alcian-blue staining. The gradual transition of Type A cells to Type B and the subsequent change of Type B to Type C suggest successive stages in maturation. These cells, especially those of Type B, resemble the mucous neck cells of the corpus and the glands of the pylorus.
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  • 89
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    Virchows Archiv 375 (1977), S. 257-262 
    ISSN: 1432-2307
    Keywords: Rabbit aorta ; Organ culture ; Endothelial regeneration ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Following an in vivo lesion of the rabbit thoracic aorta, endothelial regeneration was studied in silver-stained specimens from en face organ cultures of aortic segments with and without intercostal arteries. The in vivo lesion had been inflicted by an embolectomy catheter. Our results confirmed that endothelium regenerates from preexisting endothelium around the mounths of the intercostal arteries. A conspicuous observation was the orientation pattern of endothelial cells during regeneration. Transmission electron microscopy suggests that the cell cytoskeleton plays a role in the regulation of regeneration. The organ culture technique described, complementary to in vivo and in vitro investigations with cell cultures, seems to be a valuable tool in further investigations on factors involved in the repair of arterial tissue.
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  • 90
    ISSN: 1432-2307
    Keywords: Catecholamine ; Angiotensin ; Ouabain ; Dihydrotachysterol ; Rat heart ; Myocardial necrosis ; Electrolyte concentration ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Noradrenalin und Angiotensin in hohen Dosen allein oder in Kombination mit Strophanthin appliziert, führen bei der Ratte zu einer Erniedrigung des Gesamtcalciumgehaltes des Myocard. Dihydrotachysterol (DHT) erhöht den Calciumgehalt und zeigt elektronenmikroskopisch SchÄdigungen an Mitochondrien und Myofibrillen. Die kombinierte Gabe von DHT und Noradrenalin bzw. Angiotensin potenziert den Calciumwert, erhöht das Magnesium und lÄ\t Kalium nahezu unverÄndert. Die im Bereich der linksventrikulÄren Innenschichten ausgebildeten „Catecholaminnekrosen“ finden sich nach DHT-PrÄmedikation ubiquitÄr. Strophanthin verhindert den massiven, durch DHT- und Angiotensinmedikation induzierten Calciumstieg, wÄhrend es bei der kombinierten Gabe von DHT und Noradrenalin keine Wirkung entfaltet. Myofibrillen und Mitochondrien sind verÄndert, Calciumablagerungen sind nachweisbar, charakteristische Unterschiede fehlen.
    Notes: Summary Changes in certain tissue electrolytes brought about by injecting rats with noradrenalin (NA), angiotensin or dihydrotachysterol (DHT) were compared with the concomitant ultrastructural alterations of cardiac muscle. High doses of NA or angiotensin given singly or together with ouabain were found to lower the overall myocardial calcium concentration without accompanying structural lesions. When calcium was increased more than tenfold by the administration of DHT, electronmicroscopy revealed altered myofibrils and mitochondria. Giving DHT along with NA or angiotensin not only preserved their calcium-lowering effect, but resulted in a massive increase in tissue calcium, with magnesium levels also rising, whilst the tissue content of potassium remained almost unchanged. Following NA administration the necrotic areas, known to be confined to the inner endocardial layer after catecholamine administration, pervaded the entire cardiac muscle mass. Ouabain prevented the massive rises of tissue calcium induced by DHT given together with angiotensin but was ineffective when added to the combination of DHT and NA. In either case, both myofibrils and mitochondria displayed ultrastructural alterations although distinctive features were lacking. The data suggests that DHT acts on cellular calcium, not only by mobilising calcium from osseous structures but also by interacting with intracellular calcium homeostasis. In addition to overstimulating contractile elements, calcium is thought to exert its noxious effect in a more generall way, e.g. by binding to surface membranes, thus affecting the normal functioning and eventually the structure of mitochondria and other organelles besides myofibrils.
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  • 91
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    Virchows Archiv 376 (1977), S. 165-174 
    ISSN: 1432-2307
    Keywords: Lung ; Electron microscopy ; Pulmonary alveolar proteinosis ; Degeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopy in an infant of 4 months with pulmonary alveolar lipoproteinosis showed filling of the alveoli with osmiophilic lamellar bodies. Similar structures were present in the cytoplasm of type I alveolar epithelial cells and to a lesser extent in the capillary endothelium and interstitium. These changes represent widespread degenerative processes in the lung caused by an unidentified cytotoxic agent. In this patient the disease is comparable to the drug-induced cytotoxic animal model and differs from the dust-induced hypersecretory animal model.
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  • 92
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    Cell & tissue research 176 (1977), S. 23-36 
    ISSN: 1432-0878
    Keywords: Lateral line organ ; Shark (Mustelus manazo) ; Neuromasts ; Cell types ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The lateral line organ of the spotted shark is characterized by its semi-cylindrical shape. Each organ (neuromast) is so closely apposed to the next that the individual neuromasts are almost continuous. The neuromast is composed of receptor cells, supporting cells and mantle cells. The receptor cells bear one kinocilium and up to 40 stereocilia. Bi-directional arrangement of the receptor cells as occurs in teleosts was demonstrated. Afferent and efferent nerve endings were found at the base of the receptor cells. The supporting cells extend from the basal lamina to the free surface. Long microvilli and a cilium-like “ciliary rod” project from the top of each supporting cell. The cell contains relatively few elements of the Golgi apparatus and little rough endoplasmic reticulum, but mitochondria and filaments are abundant. The mantle cell limits the lateral margin of the neuromast. It is distinguished from the supporting cell because of its long crescent-shaped nucleus and scarce, short microvilli. Myelinated nerve fibres are found in the subepithelial connective tissue but not in the epithelium. The fine structure of the shark lateral line organ suggests that this organ is in an intermediated step of evolution between that of lamprey and teleost.
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  • 93
    ISSN: 1432-0878
    Keywords: OsO4 ; Cholesterol ; Symbiotes ; Aphids ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pea aphids left for 48 h in unbuffered osmium tetroxide show heavy staining of many organelles in the symbiote-containing cells (mycetocytes and sheath), embryos and oenocytes very similar to that characteristic of mammalian sterol-synthesizing cells. However, the staining of the pea-aphid cells is, to a large extent, dependent on the presence of cholesterol benzoate, or free cholesterol, in the aphid's diet. In aphids cultured in vitro with 3H mevalonate in the presence of added cholesterol, the incorporation of label into the cholesterol and lanosterol fractions is significantly reduced. If the dietary cholesterol effects a similar inhibition in vivo, the cholesterol-dependent osmium staining could be due to precursors(s) of cholesterol accumulating in the intracellular sites described. There is also osmium staining of large (normally electron-transparent) vacuoles in mycetocytes, gut and fat body, irrespective of dietary cholesterol.
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  • 94
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    Cell & tissue research 176 (1977), S. 417-429 
    ISSN: 1432-0878
    Keywords: Fat body ; Galleria mellonella ; Basement membrane ; Ruthenium red staining ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fat body lobes of Galleria mellonella are surrounded by basement membrane — a fine granular layer of connective tissue. This membrane has an affinity for ruthenium red. The results obtained after treatment of the fat body with neuraminidase, hyaluronidase, phospholipase C and proteolytic enzymes suggest that glycoproteins and phospholipoproteins are constituents of this basement membrane. The basement membrane also has the ability to bind concanavalin A-peroxidase, which is associated with the presence of mannoside residues.
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  • 95
    ISSN: 1432-0878
    Keywords: Skeletal muscle ; Protamine ; Endocytosis ; Autophagic vacuolation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The uptake in vitro of horseradish peroxidase (HRP) in mouse skeletal muscle was examined by electron microscopy and chemical determination. In muscles exposed to an HRP solution for 60 min at +37°C, HRP infiltrated the basal lamina of muscle fibres and caused an intense labelling of their sarcolemma. In addition HRP was found within the transverse tubules. Exposure to HRP for 30 min at +37°C followed by HRP together with a polycationic protein (protamine) for 30 min at +37°C caused an intracellular vesicular uptake of HRP. Intracellular HRP was found in numerous vesicles, membrane limited bodies and vacuoles. Protamine also induced focal autophagic vacuolation with progressive muscle fibre degeneration. An intracellular HRP uptake or muscle cell vacuolation could not be detected in the absence of protamine or when the incubation temperature was + 4°C. Chemical determination of HRP uptake was in general agreement with the morphological results. The uptake of HRP in the presence of protamine was stimulated at +31°C and blocked at +4°C. The results suggest that in skeletal muscle in vitro intracellular uptake of macromolecules occurs by endocytosis.
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  • 96
    ISSN: 1432-0878
    Keywords: Electron dense plaques ; Pancreatic islets ; Parathyroids ; Electron microscopy ; Calcium binding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Small electron dense plaques (EDP) were found in the plasma membrane of pancreatic islet A-, B- and D-cells and parathyroid chief cells of mice and gerbils. The identification of the EDP was facilitated by the use of special fixation techniques. The EDP may represent sites of calcium binding in the cell membranes.
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  • 97
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    Cell & tissue research 177 (1977), S. 127-140 
    ISSN: 1432-0878
    Keywords: Microtubules ; Retina ; Electron microscopy ; Rainbow trout
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the retina of the rainbow trout (Salmo gairdneri, Richardson) two types of microtubular structures are demonstrated. Besides the normal type of microtubules (about 200 Å in diameter), occurring in all cell types of the retina, a second type is described which is termed microtubule-like structure (MLS) because of its extracellular localization. These MLS have a diameter of about 250 Å under the same preparative conditions in which the normal microtubules appear 180–200 Å thick. The interspace between the tubules is smaller than between the microtubules. Specific MLS to membrane associations exist, which are analyzed by serial sectioning and tilting procedures. It is suggested that the MLS have their origin at small membranous extrusions of the plasmalemma. These extrusions could contain nucleation sites for the MLS-formation within the extracellular space. It remains unknown which cell type produces the MLS proteins and which factors are responsible for the aggregation of the subunits to intact MLS.
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  • 98
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    Cell & tissue research 177 (1977), S. 221-226 
    ISSN: 1432-0878
    Keywords: Actin-like filaments ; Myoid cell ; Testis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Microfilaments in the myoid cells of the peritubular tissue in the mouse, swine and human testis bind heavy meromyosin (HMM) and form arrowhead complexes. The periodicity of the arrowhead complexes is about 35 nm. Individual filaments show arrowheads that point in the same direction. Opposing polarity of the HMM-bound filaments is also observed. The microfilaments do not bind HMM in the presence of 10 mM ATP. After treatment with the contraction medium of Hoffmann-Berling, the filaments appear to be undulated. These observations indicate that the microfilaments in the myoid cell are actin-like in nature. A small number of thicker filaments (about 10 nm in diameter) which do not bind HMM is also observed in the cell. Microfibrils which have been reported around the human myoid cell are also found in the swine.
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  • 99
    ISSN: 1432-0878
    Keywords: Optic neuropile ; Crustacea ; Catecholamine ; Fluorescence histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The crustacean optic neuropiles, the lamina ganglionaris and especially the medulla externa, show a specific pattern of green fluorescence with the fluorescence histochemical method of Falck-Hillarp. Normally, only the terminals and the cell bodies fluoresce, but in reserpine-treated animals exogenous catecholamines are taken up by the whole adrenergic neuron and are thus visualized as a whole. Incubating crayfish optic neuropiles in dopamine or α-methylnoradrenaline after reserpine treatment demonstrated a tangential neuron connecting the lamina and the medulla externa. The morphology of this tangential neuron differs from the two types of tangential neurons, Tan1 and Tan2, previously characterized with Golgi techniques. The catecholaminergic neuron thus constitutes a third tangential neuron type.
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  • 100
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    Cell & tissue research 182 (1977), S. 401-407 
    ISSN: 1432-0878
    Keywords: Microtubules ; Sciatic nerve (rat) ; Tannic acid ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Tannic acid in glutaraldehyde was used to stain microtubules in myelinated and unmyelinated axons of rat sciatic nerve. In the majority of areas the tannic acid failed to penetrate the unmyelinated axons whilst penetrating neighbouring myelinated axons, suggesting a difference in the ability of the two types of nerves to exclude tannic acid. Where tannic acid had penetrated the unmyelinated axons the 13 protofilament substructure and size of the microtubules appeared identical to those seen in the myelinated axons.
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