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M Bergmann

Publications and source records attributed to M Bergmann.

At least 109 records · Page 6Linked to original sources
PubMed1996

Different variants of frontotemporal dementia: a neuropathological and immunohistochemical study.

Histological and immunohistochemical findings in 20 cases of frontotemporal dementias-8 cases of dementia of frontal lobe type (DFT), 7 cases of Pick's disease (PD), and 5 cases of motor neuron disease with dementia (MND/D)-are presented. Common features of all three syndromes were: frontotemporal atrophy, involvement of subcortical nuclei, and swollen chromatolytic cells. Ubiquitin (Ub)-positive and tau-negative inclusions in cortical, hippocampal, and motor neurons were found in MND/D and DFT cases, suggesting a common pathogenesis of MND/D and DFT. MND/D showed the same cytoskeletal alterations in motor nuclei as MND without dementia: Bunina bodies and skein-like, Ub-positive inclusions. DFT differed from PD in the preponderance of histopathological changes in upper cortical layers, the sparseness of chromatolytic cells, and the absence of tau-positive Pick bodies (PBs). There were, however, two transitional cases showing Pick-type histology but no PBs, thus linking DFT and PD. PBs expressed chromogranin B and secretoneurin strongly, but chromogranin A only weakly. They were negative for the 70-kDa heat-shock protein, metallothionein, and glutathione-S-transferase.

Adult↗
PubMed1996

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL): a morphological study of a German family.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is characterized clinically by recurrent cerebral infarcts, subcortical dementia and pseudobulbar palsy, and morphologically by a granular degeneration of cerebral and, to a lesser degree, extracerebral blood vessels. We present morphological findings in a further German family affected by CADASIL. The index case showed the typical periodic acid-Schiff-positive granular degeneration of vascular smooth muscle cells (VSMC) in cerebral vessels, which did not react with antibodies against various immunoglobulins or complement factors. Ultrastructurally, granular osmiophilic material (GOM) covered the VSMC in different cerebral regions as well as in extracerebral organs (muscle, nerve, skin, small and large intestine, liver, kidney and heart). Skin biopsy samples from other family members of the last two generations also revealed GOM irrespective of the clinical symptomatology (CADASIL, migraine only or asymptomatic). Patients in the third generation had higher amounts of GOM in skin vessels than did asymptomatic or migraine patients in the fourth generation. We conclude that skin biopsy is a useful and less invasive screening method for the differential diagnosis of CADASIL.

Adult↗
PubMed1996

Mutations in the nonconserved noncoding sequences of the influenza A virus segments affect viral vRNA formation.

Influenza A virus replication and packaging is mediated by cis-acting signals, which are located at the 3' and the 5' end of the viral segments. The terminal residues can be divided into conserved and nonconserved residues. We have constructed a mutant influenza A/WSN/33 virus, which contains multiple mutations in the nonconserved residues of the neuraminidase (NA) segment. This virus shows a segment-specific reduction of the genomic RNA content in the infected cell and in the progeny virus. Further mutants and revertant viruses revealed that it was not possible to define specific residues, which were responsible for the reduction of the NA-specific RNA. Thus, it appears that an efficient vRNA formation is dependent on the synergistic effect of the terminal sequences.

Animals↗
PubMed1996

Macrophages in multiple sclerosis.

Macrophages are important effector cells involved in the pathogenesis of demyelination in multiple sclerosis (MS). Macrophage differentiation was studied in a series of 158 MS plaques from 43 patients obtained at different stages of the disease. Macrophages were identified by immunocytochemistry using a panel of antibodies recognizing different formalin- and paraffin-resistant macrophage activation antigens. The number of cells stained with each antibody was related to the demyelinating activity of the lesions as detected by the presence of myelin degradation products as well as to the category of MS tissue. Highest numbers of macrophages were observed in actively demyelinating and early remyelinating lesions using immunocytochemistry for the panmacrophage marker Ki-M1P. Lower numbers were encountered in inactive, demyelinated or late remyelinated lesions. The acute stage inflammatory macrophage markers MRP14 and 27E10 were selectively expressed in early and late active lesions, thus allowing the identification of actively demyelinating lesions. The chronic stage inflammatory macrophage marker 25F9, in contrast, showed a continuous expression also in inactive lesions. The different types of MS tissue revealed significant differences in their macrophage response. The most intense macrophage infiltration was seen in acute MS cases whereas lesions of early and late chronic MS showed lower macrophage levels. These findings indicate a differentiated pattern of macrophage activation in MS depending on the stage of the demyelinating activity as well as on the category of MS tissue. Furthermore, these macrophage markers give new parameters for staging the inflammatory and demyelinating activity of MS lesions.

Acute Disease↗
PubMed1996

Ubiquitin-positive inclusions in different types of multiple system atrophy: distribution and specificity.

Multiple system atrophy (MSA) is a neurodegenerative disorder that encompasses different clinicopathological syndromes, either occurring alone or with a variable degree of overlap. Oligodendroglial, intracytoplasmic argyrophilic and ubiquitin-reactive inclusions are regarded as a histologic hallmark. We examined the distribution and specificity of these ubiquitin-reactive inclusions (UBRI) in 20 cases of MSA (7 cases of sporadic adult olivoponto-cerebellar atrophy [OPCA], 1 case of hereditary adult OPCA, 4 cases of infantile OPCA, 2 cases of Shy-Drager-Syndrome [SDS], 4 cases of striatonigral degeneration [SND] and 2 cases of non-classified atrophy of multiple systems) and 93 control cases with various disorders. Antibodies were used against ubiquitin, PGP 9.5, TAU-protein, glutathion-S-transferase (GST) and metallothionein (MT). Oligodendroglial UBRI were detected in all but 2 cases of sporadic adult MSA and 3 controls, whereas they were absent in hereditary and infantile OPCA. They could also be recognized with Gallyas stain and anti-TAU. Immunopositivity was also seen with GST (11 cases), PGP 9.5 (4 cases) and MT (1 case). Distribution of oligodendroglial UBRI, although not showing topographical linkage to neuronal degeneration in all cases, does not seem to occur in a haphazard pattern.

Adolescent↗
PubMed1996

Ki-67 and biological behaviour in meningeal haemangiopericytomas.

The biological behaviour of meningeal haemangiopericytomas was retrospectively studied using immunohistochemical staining with MIB1, a monoclonal antibody against the Ki-67 antigen, a nuclear protein related to cell proliferation. Paraffin-embedded material from 62 tumours from 40 patients were investigated. The proliferating compartment of the tumours was estimated by evaluating the MIB1 staining index, i.e. the percentage of MIB1 positive nuclei in at least 1000 counted tumour cells in representative areas. The staining index ranged from 1.24% to 39.01%. Statistical analysis revealed no significant correlation between the staining index and recurrence-free survival (chi 2 = 0.3922, P = 0.5311). Long-term observation (> 100 months), however, revealed a tendency to longer survival in the group with a staining index less than 5%. According to our results, the MIB1 staining index does not contribute to the accuracy of predicting the clinical outcome of meningeal haemangiopericytomas.

Adolescent↗
PubMed1996

[Intravascular lymphomatosis of the nervous system--case report and review of the literature].

We report on a typical case of intravascular lymphomatosis, a rarely diagnosed, generalised intravascular lymphoma usually of the B-cell type. In most cases there is a lack of clear haematological findings but in more than 50% intravascular lymphomatosis presents with symptoms of the central nervous system. Every rapidly progressive neurological deficit, especially the association of a subacute dementia with a spinal syndrome may suggest IVL-NS. However, careful examination may detect minor features for a systemic process in 25-80% i.e. B-symptoms elevation of ESR and LDH. Neurological imaging demonstrates multifocal lesions in the CNS with affinity to the deep white matter consistent with a microvascular or demyelinating disease. Angiographically IVL-NS may mimic cerebral vasculitis. CSF findings are nonspecific. Because diagnosis can only be made histologically, a cerebral biopsy should be undertaken in suspected cases. Usually the course of the disease is fatal. Therapy involving steroids, combination polychemotherapy or radiation met with only minor success.

Aged↗
PubMed1996

Immunohistochemical detection of immature Sertoli cell markers in testicular tissue of infertile adult men: a preliminary study.

Testicular biopsy specimens from oligozoospermic infertile patients are characterized by different types of spermatogenic impairment in adjacent seminiferous tubules, a phenomenon called mixed atrophy. In order to evaluate possible involvement of the state of Sertoli cell differentiation, the distribution pattern of anti-Müllerian hormone (AMH), vimentin and cytokeratin intermediate filament proteins was investigated by means of immunohistochemistry. AMH immunoactivity occurs in Sertoli cells of the normal postnatal prepubertal testis, but it is absent in the adult testis with normal spermatogenesis. In the case of mixed atrophy, AMH immunoactivity was found in Sertoli cells of tubules showing spermatogenic arrest at the level of spermatogonia and in tubules showing Sertoli-cell-only (SCO) syndrome. Vimentin was expressed regularly in Sertoli cells independent of spermatogenic impairment or the state of Sertoli cell differentiation. Cytokeratin immunoactivity occurs in Sertoli cells of the normal postnatal prepubertal testis. Furthermore, cytokeratin expression was found in Sertoli cells of tubules showing spermatogenic arrest at the level of spermatogonia and in some SCO tubules. Co-expression of AMH and cytokeratin suggests that spermatogenic impairment such as spermatogenic arrest and SCO syndrome in human seminiferous tubules is associated with a population of Sertoli cells showing a prepubertal stage of development. The different pattern of AMH and cytokeratin expression in SCO tubules indicates that Sertoli cells in SCO syndrome show a mosaic pattern of differentiation.

Adult↗
PubMed1996

Rab3 proteins and SNAP-25, essential components of the exocytosis machinery in conventional synapses, are absent from ribbon synapses of the mouse retina.

GTP-binding rab proteins, present in synaptic vesicles and endocrine secretory granules, have been shown to be involved in the control of regulated exocytosis. We found rab3 proteins in immunoblots of diverse areas of the mouse central nervous system (spinal cord, olfactory bulb, hippocampus, cerebellum and neocortex). Immunohistochemical observations at light- and electron-microscopical levels in the hippocampus and other areas revealed rab3 proteins in virtually all synaptic fields and terminals of the areas investigated. In the retina, rab3A immunoreactivity was confined to the inner and outer plexiform layers. Ultrastructural examination revealed that rab3A was present in conventional terminals in the inner plexiform layer and in horizontal cell processes of the outer plexiform layer. In contrast ribbon synapses, which play a key role in transferring information from the photoreceptor cells to the central nervous system, were immunonegative. We also tested whether other proteins of the rab3 family are present in ribbon synapses. However, using an antibody recognizing rab3B and rab3C in addition to rab3A, we found no immunoreactivity in these synapses. Interestingly, we observed also no immunoreactivity for synaptosomal-associated protein 25 (SNAP-25) in ribbon synapses, but conventional synapses and horizontal cell processes were heavily stained. Our data show that the known rab3 and SNAP-25 isoforms, which are components of the secretory apparatus of conventional synapses, are absent from ribbon synapses of the retina. Our observations suggest different mechanisms of transmitter exocytosis in conventional and ribbon terminals.

Animals↗
PubMed1996

Primary non-Hodgkin lymphomas of the CNS-proliferation, oncoproteins and Epstein-Barr-virus.

Primary cerebral lymphomas (PCL's) are rare tumors which, however, occur with increasing frequency. The present study investigated 55 PCL's of B-cell type, 36 in immunocompetent and 19 in AIDS-patients and 6 cases of intravascular lymphomatosis. In immunocompetent patients, proliferative indices as evaluated by PC10 and MIB1 reflected the histologic grade. Low grade tumors had a mean PCNA and MIB-1 count of 19 and 18.8 (SD 14.7 and 13.2), respectively, and high grade neoplasias showed counts of 56.7 and 47.1 (SD 19 and 17.4), respectively. No correlation of both indices with patient survival was found. 21 cases (58.3%) displayed p53-positivity of varying degree and 19 cases (52.7%) harbored bcl-2 positive neoplastic cells. Immunocompetent cases were always negative for Epstein-Barr virus RNA and lmp-1-protein. In AIDS-cases, 13 cases (68.4%) showed up lmp-1 positivity and 15 cases (78.9%) had EBER-RNA. bcl-2 positive cells were detected in 5 cases (26.3%) and all cases were p53-negative. These results are in keeping with a role of EBV in the pathogenesis of primary cerebral lymphomas in AIDS-, but not in immunocompetent patients. None of the cases with intravascular lymphomatosis showed an expression of bcl-2 or p53 oncoproteins or lmp-1 and none had EBER-RNA.

Adult↗
PubMed1996

[Tumorous neurosarcoidosis--a rare manifestation of Boeck disease--3 cases and review of the literature].

Neurosarcoidosis mimicking CNS tumours represents a rare manifestation of Schaumann's disease. The central or peripheral nervous system is clinically involved in 5% of sarcoidosis, basal parts of the brain being mainly affected by the inflammation. This location of the process causes basal meningitis with cranial nerve paresis as well as parenchymal granulomatosis around the third ventricle and hypophysis. Solid, space-occupying lesions rarely occur, evoking problems in the differentiation from cerebral tumours. We report three cases of neurosarcoidosis presenting as intracranial tumours, where a space-occupying lesion was the first of only manifestation of sarcoidosis. The lesions in our cases were found in parietal and parieto-occipital cortex and in the fourth ventricle and vermis cerebelli, respectively. These locations are unusual, since most of the reported cases were affecting the temporal lobe. We review the literature and discuss the role of neurosarcoidosis in the differential diagnosis of intracranial tumours.

Brain↗
PubMed1995

Morphomechanics of the humero-ulnar joint: I. Joint space width and contact areas as a function of load and flexion angle.

BACKGROUND: Previous studies have shown that the trochlear notch is deeper than necessary for an exact fit with the humerus. However, humero-ulnar joint space width and contact areas have so far not been quantified for variations in the load and angle of flexion. METHODS: Six fresh cadaveric specimens were investigated at 30 degrees, 60 degrees, 90 degrees, and 120 degrees of flexion and at loads of 25 and 500 N, simulating resisted elbow extension. The joint space width and contact were determined, using polyether casting material. RESULTS: At 25 N all joints made contact in the ventral and dorsal aspects of the articular surfaces, whereas in the depth of the trochlear notch the joint space was on average between 0.3 and 2.8 mm wide, with some variation between individuals. At 500 N the joint space width was considerably reduced and the contract areas expanded towards the depth of the notch. The size of the dorsal contact areas was significantly smaller at 30 degrees and that of the ventral ones at 120 degrees, their ventro-dorsal ratio decreasing considerably from 30 degrees to 120 degrees (p < 0.01). CONCLUSION: These results indicate that the size of the contact areas depends to a slight extent on the joint position, but that at all loads and flexion angles a bicentric contact and an important central joint space width emerge because of the concave incongruity of the joint. These data may be used for numerical calculations, analysing the effects of incongruity on the joint stress and on the functional adaptation of the subarticular tissues.

Adult↗
PubMed1995

Nemaline myopathy: two autopsy reports.

Nemaline myopathy belongs to the group of congenital non-progressive myopathies; however, in rare cases death occurs in early infancy. We report two cases of rapidly fatal nemaline myopathy. The first patient, who died at the age of 26 months, showed atrophy of type 1 fibers containing numerous rods in biopsy sections. Biopsy of the second patient, who had died at the age of 5 months, revealed severe maturational arrest and myopathy, but rods were so rare that diagnosis could only be made at the ultrastructural level. Autopsy of both patients showed that atrophy of type 1 fibers and maturational arrest had disappeared in the very same muscles; rods had moved to a central position in the first and significantly increased in number in the second case. Diaphragma muscles contained abundant amounts of rods in both cases. The cardiac musculature showed a few rods only in the first patient, who had developed heart insufficiency 11 months prior to death. Immunohistochemical analysis showed that rods did not contain desmin or ubiquitin.

Biopsy↗
PubMed1995

Dysembryoplastic neuroepithelial tumour of the cerebellum.

A case of dysembryoplastic neuroepithelial tumour of the cerebellum occurring in a 28-year-old woman is presented. The lesion extended from the cortex of the inferior vermis upwards into the white matter. Histologically, it exhibited areas of microcystic cerebellar astrocytoma and glial regions with hamartomatous blood vessels as well as areas with oligodendrocyte-like cells (OLC) with a delicate, fibrillary stroma lying in a mucinous, often microcystic matrix. The OLC showed prominent rosette formation and immunohistochemical features suggesting neuronal, i.e. granule cell, differentiation.

Adult↗
PubMed1995

Onuf's nucleus is frequently involved in motor neuron disease/amyotrophic lateral sclerosis.

Involvement of Onuf's nucleus (ON) in 28 cases of amyotrophic lateral sclerosis/motor neuron disease (MND/ALS) with different clinical syndromes is reported. Although significant neuronal loss was absent, all cytoskeletal abnormalities typical of alpha-motor neurons in MND/ALS were found in ON. Spheroids were detected in 53.5% of cases; 0.6-4.5% of ON neurons contained Bunina bodies, which were present in 42.8% of cases. Ubiquitin-reactive inclusions (UBRI) of filamentous and hyaline type were found in 57.1% of cases and in 1.2-10.7% of ON neurons. Cases with pyramidal tract involvement (ALS) were involved by UBRI in 76.5%, whereas cases with progressive spinal muscular atrophy revealed the same inclusions in only 27.2%. No similar inclusions were present in sacral parasympathetic intermediolateral nucleus. It can be concluded, therefore, that ON belongs to the somatic motor system and is principally vulnerable to MND/ALS, albeit to a lower degree.

Adult↗
PubMed1995

Spontaneous recrudescence of spermatogenesis in the photoinhibited male Djungarian hamster, Phodopus sungorus.

Photosensitive rodents exposed to inhibitory short photoperiods become insensitive to this environmental factor after prolonged exposure. During the following process of spontaneous recrudescence, the animals that have adapted to the winter season show a return of all seasonal parameters. In the Djungarian hamster, obvious photoperiod-dependent changes are reinitiation of the reproductive organs, a 20-30% increase in body weight, and a moult from whitish fur into brown summer fur. This study was designed to analyze the morphological and endocrinological changes occurring during spontaneous testicular recrudescence in male Djungarian hamsters under prolonged short photoperiods. Two experiments were performed 1) to analyze the time-dependent changes in groups of hamsters exposed to short photoperiods and 2) to observe testicular and humoral changes in individual animals during spontaneous recrudescence. Regrowth of the testes and seminal vesicles did not begin before Week 18 in short photoperiods. While serum testosterone did not increase before Week 24, serum FSH had already returned to normal values from Week 18 onwards. Individual analysis by enzyme histochemistry revealed that 3 beta-hydroxysteroid-dehydrogenase activity in Leydig cells was not restored before testicular weights of more than 400 mg were observed and the first wave of spermatogenesis had reached the stage of elongated spermatids. This indicates that the testicular testosterone production was low until a status of testicular recrudescence had been achieved, at which point the testis showed complete qualitative spermatogenesis and a restoration of the Sertoli cell actin filaments. These data suggest that the process of early spontaneous recrudescence in male Djungarian hamsters appears to be initiated by the restoration of serum FSH rather than by testosterone.

3-Hydroxysteroid Dehydrogenases↗
PubMed1995

The relative amount of an influenza A virus segment present in the viral particle is not affected by a reduction in replication of that segment.

The principles of influenza A virus replication and packaging are not fully understood. In order to investigate the signals required for these processes we have introduced mutations in the terminal non-coding region of an influenza A virus neuraminidase (NA) gene. Specifically, we have obtained two viruses, NA/X and NA/Y, which produced a reduced amount of NA-specific genomic RNA in infected cells but not in the viral particle. These data indicate that (i) specific signals which affect the amount of RNA in the viral particle are distinct from those required for viral replication and (ii) the amount of packaged RNA is not strictly dependent on the amount of RNA produced during replication. In addition, mutant NA/Y was shown to be effectively attenuated in mice. Thus, diminished replication of one viral segment might be a principle on which to base a live influenza virus vaccine.

Animals↗