PubMed Health⌕ Search

Biomedical subjects

A Bornemann

Publications and source records attributed to A Bornemann.

At least 55 records · Page 3Linked to original sources
PubMed1996

An immuno-electron-microscopic study of human thymic B cells.

Thymic B cells are a constituent of normal human thymic medulla. They are supposed to play a role in T cell maturation. Thymic B cells have been characterized morphologically and immunohistochemically at the light-microscopic level. Their ultrastructural appearance in vivo has not been demonstrated. Six normal infantile thymi were immunolabelled with the pan-B cell marker CD20 using a pre-embedding technique and viewed at the electron-microscopic level. Cells expressing CD20 had long cytoplasmic processes. They were all "asteroid" in shape and in close contact with thymocytes. Also, their long cytoplasmic processes intermingled with cytoplasmic processes of cells that were presumed to be interdigitating reticulum cells (IDC) based on morphological criteria. Thymic B cells may act in concert with IDC during T cell maturation.

Antigens, CD20↗
PubMed1996

A mild adult myopathic variant of type IV glycogenosis.

Type IV glycogenosis is usually a rapidly progressive disease of early childhood, causing death before 4 years of age. It is characterized by hepatosplenomegaly, cirrhosis, and chronic hepatic failure. Muscle involvement is generally overshadowed by liver disease. A mild non-infantile variant of type IV glycogenosis has been described in a few patients. In some of them, the patients suffered foremost from chronic progressive myopathy. We here report on a female patient aged 51 years who had experienced difficulties in climbing stairs for 2 years due to leg weakness. EMG revealed a myopathic pattern. The muscle biopsy findings revealed polyglycosan bodies. Biochemical investigation showed absence of branching enzyme in muscle but not in leukocytes and fibroblasts.

Adult↗
PubMed1996

Site-specific regulation of organic osmolytes along the rat nephron.

The regulation of organic osmolytes was investigated in acute furosemide and chronic lithium diuresis along the nephron and in urinary bladder of rats. Sorbitol, myo-inositol, glycerophosphorylcholine, and betaine were measured enzymatically or by high performance liquid chromatography in homogenates and bioluminometrically in microdissected tubules. In untreated rats, all osmolytes except myo-inositol increased along the corticopapillary axis. An efflux of all osmolytes (-50%) was observed in homogenates of outer and inner medulla after acute furosemide diuresis (15 min, urinary osmolality = 329 mosmol/kgH2O) and for both polyols in microdissected tubules (30 min). In urinary bladder, only low concentrations of myo-inositol were found not to be affected by furosemide treatment. Chronic lithium treatment (7 days; urinary osmolality = 385 mosmol/kgH2O) decreased inner medullary but not outer medullary osmolyte concentrations. The results confirm a site-specific organic osmolyte pattern along the rat nephron, which is rapidly changed in a segment-specific way by different mechanisms of diuresis. The bladder epithelium does not accumulate organic osmolytes because no "osmotic gap" exists across the basolateral membrane. The osmotic difference across the apical membrane is maintained by the apical tightness of these cells.

Animals↗
PubMed1996

Three siblings with Walker-Warburg Syndrome.

The Walker-Warburg syndrome (WWS) is an autosomal recessive disease entity within the framework of "cerebro-ocular-muscular syndromes". The gene locus is still undetected. Its diagnostic criteria have been firmly established in the literature on newborns or infants affected with the disease. However, a diagnosis of severe pathologic conditions must often be made on the basis of ultrasound examination at a fetal age. It is therefore necessary to examined whether the diagnostic criteria are sufficient to warrant a diagnosis at the fetal stage. We here report on a new family affected with WWS. Two elder siblings had presented with epileptic seizures, eye abnormalities as well as multiple skeletal dysplasias (the latter finding in the first child only) in the neonatal period, and died in their first years. Postmortem examination of the second child revealed type II lissencephaly, buphthalmos, and undifferentiated retina with rigid retinal folds. Skeletal muscle tissue was not examined. In a sibling fetus, bilateral cataract was detected in the 17th gestational week by ultrasonographic examination. Postmortem examination in the 23rd gestational week revealed type II lissencephaly and bilateral cataract. Skeletal muscle was normal. Taken together, all siblings were diagnosed as Walker-Warburg syndrome. In the fetal case, prenatal diagnosis could only be made with confidence against a background of a positive family history.

Abnormalities, Multiple↗
PubMed1996

Nerve and muscle biopsy in a case of hereditary motor and sensory neuropathy type III with basal lamina onion bulbs.

A girl presented at age 8 months with generalized hypotonia and areflexia. The parents were unrelated and without symptoms. At the age of 2 years and 10 months she was able to stand and walk with support. Intellectual development was normal. The mean fibre size in the lateral vastus muscle was normal, the variability was slightly increased. Type I and II fibres tended to be aggregated, but there was no type grouping. Motor and sensory nerve conduction velocities were less than 6 m/s. The sural nerve lacked myelin sheaths, and large non-myelinated axons were surrounded by concentric layers ('onion bulbs') of basal lamina material. The disease was classified as 'autosomal recessive hereditary motor and sensory neuropathy type III(HMSN (III) with basal lamina onion bulbs'. The muscle biopsy findings suggest that congenital amyelination or hypomyelination does not necessarily result in neurogenic atrophy.

Biopsy↗
PubMed1995

Amyloidomas of the gasserian ganglion.

An amyloidoma is a local deposition of amyloid that becomes a space-occupying lesion. Amyloidomas of the central nervous system are very uncommon lesions and only four amyloidomas of the gasserian ganglion have been reported so far. We present the neuroradiologic and surgical characteristics of three more amyloidomas of the gasserian ganglion seen at one neurosurgical department in 11 years.

Journal Article↗
PubMed1994

Immunocytochemistry of M-cadherin in mature and regenerating rat muscle.

BACKGROUND: Cadherins are transmembrane proteins mediating calcium-dependent cell-cell adhesion in a cell type-specific manner by means of homophilic binding. M(muscle)-cadherin is a recently detected member of the cadherin family. METHODS: We have investigated the localization of M-cadherin in normal and aneurally regenerating skeletal muscle of rat by means of pre-embedding immunocytochemistry. The antibody was directed against the extra-cellular domain of M-cadherin. RESULTS: Myoblasts and myotubes in regenerating muscles tended to be arranged in clusters enclosed by a common basal lamina. Satellite cells of mature muscle fibers were attached to the underlying fiber without separating basal lamina. Reactivity for M-cadherin was restricted to the plasma membranes of myoblasts and satellite cells, and was most intense at the membrane areas facing adjacent myotubes or myofibers. Myoblasts interposed between two myotubes were stained on the entire surface. The adjacent plasma membrane of the otherwise negative myotube or muscle fiber, was stained as well, and extracellular reaction product was in the gap between the cells. CONCLUSION: The cellular localization of M-cadherin may indicate that M-cadherin is involved in calcium-dependent adhesion between satellite cells and muscle fibers or, by means of interposed myoblasts, between the clustered myotubes in a regenerating muscle.

Animals↗
PubMed1993

Amyloidoma of the gasserian ganglion as a cause of symptomatic neuralgia of the trigeminal nerve: report of three cases.

Three cases of symptomatic neuralgia of the trigeminal nerve due to an amyloidoma in the gasserian ganglion are described. The correct diagnosis was not made prior to histological examination of the surgical biopsy specimens. Medical history and clinical observation led to the diagnosis of a malignant process of the nasal cavities in the first patient; of an inflammatory dental focus in the second patient; and of multiple sclerosis in the third patient. CT findings were normal in cases 1 and 2; in case 3, a schwannoma was suspected from the CT appearances. In case 1, MRI had not been performed; in cases 2 and 3, MRI revealed a tumour mass which was also considered to be a schwannoma. Histologically, the tumours consisted of masses of amyloid deposits which had largely replaced the pre-existing ganglionic cells and satellite cells. Electron microscopy confirmed the fibrillar structure of the deposits. Immunohistochemistry and immunocytochemistry revealed the amyloid to belong to the AL-lambda subtype.

Adult↗
PubMed1993

Desmin pathology in neuromuscular diseases.

Desmin is an intermediate filament protein that in striated muscle is normally located at Z-bands, beneath the sarcolemma, and prominently at neuromuscular junctions. It is abundant during myogenesis and in regenerating fibers, but decreases in amount with maturation; in regenerating and denervated muscle fibers it is co-expressed with vimentin. Aggregates of desmin occur as nonspecific cytoplasmic bodies or cytoplasmic spheroid complexes, similar to the aggregates of keratin filaments in Mallory bodies or the neurofilament aggregates in Lewy bodies. In all three instances, alpha-B crystallin may be associated with desmin. There are now increasing numbers of neuromuscular disorders in which abnormal amounts of desmin, some abnormally phosphorylated, feature prominently in muscle fibres. Several of these diseases, including spheroid body myopathy, granulo-filamentous body myopathy and the dystrophinopathies, are familial. Ultrastructural and immunohistochemical studies of desmin have considerably broadened our understanding of the pathology of the cytoskeleton in muscle fibers and in certain hereditary neuromuscular diseases.

Animals↗
PubMed1993

Anti-vimentin staining in muscle pathology.

The intermediate filaments of immature muscle fibres contain desmin and vimentin; vimentin is lacking in mature fibres. Regenerating fibres react with anti-vimentin antibodies and more intensely for desmin than mature fibres. The aim of the present study was to evaluate anti-vimentin staining for muscle pathology. Anti-vimentin-reactive fibres were found in 40 of 89 biopsies assessed. Fifteen patients with progressive destructive myopathy, infantile spinal muscular atrophy, clinically suspected Leigh's disease or unclassifiable congenital myopathy had between 1% and 95% vimentin-positive fibres. Less than 1% positive fibres were found in 25 patients with neuropathy with secondary myopathy or chronic myopathic conditions. Vimentin-positive fibres were lacking in 20 normal biopsies, in eight biopsies with neuropathic and in 21 biopsies with mild or non-destructive myopathic changes. We conclude that staining with anti-vimentin antibodies is a useful indicator for muscle fibre regeneration; it may help establish the diagnosis in infantile spinal muscular atrophy when the histopathology is non-characteristic. The high incidence of reactive fibres in some congenital or early-onset disorders may indicate developmental arrest.

Adolescent↗
PubMed1992

Desmin and vimentin in regenerating muscles.

Desmin is a normal constituent of skeletal muscle fibers; vimentin is contained in myoblasts and connective tissue cells. The intracellular localization of both intermediate filament proteins in regenerating rat muscles was investigated by immunohisto- and immunocytochemistry. Necrosis was induced by hot Ringer solution. Desmin and vimentin were diffusely distributed in myoblasts and young myotubes. Both proteins became arranged in a sarcomeric fashion between the Z-lines when the sarcomeres got into register. Desmin reactivity persisted, but vimentin disappeared after about 2 weeks. Traces were found for up to 4 weeks. This observation is in contrast to findings in fetal and cultured muscles in which several authors did not find expression of vimentin after myoblast fusion. The presence of vimentin may well be a useful marker for regenerated muscle fibers in muscle biopsies from patients with neuromuscular disorders.

Animals↗
PubMed1992

Suprasellar granular cell tumor.

A case of a suprasellar granular cell tumor, approximately 1.5 cm in diameter, in a 68-year-old woman is described. Diagnosis was established postoperatively by histopathological examination of the tumor tissue. The preoperative computed tomographic scan revealed a slightly hyperdense suprasellar mass with strong contrast enhancement. There was no evidence of calcification. The T1-weighted image on magnetic resonance imaging scan showed an isointense tumor with non-homogeneous enhancement after intravenous gadolinium diethylene-triamine-pentaacetic acid. In the proton-weighted image, the suprasellar mass presented a non-homogeneously enhanced signal. A non-homogeneous signal reduction was seen in the T2-weighted image.

Aged↗
PubMed1992

Subcellular localization of GLUT4 in nonstimulated and insulin-stimulated soleus muscle of rat.

Soleus muscles of fed rats were fixed by vascular perfusion with paraformaldehyde; individual fibers were teased and immunostained with a polyclonal antibody against the COOH-terminal of GLUT4. The binding sites were visualized by a horseradish peroxidase-coupled secondary antibody and diaminobenzidine. The fibers were embedded in epoxy resin and studied by electron microscopy. Strong immunoreactivity was found in subsarcolemmal clusters of vesicles and cisternae, Golgilike structures, and triadic junctions. Clusters of vesicles between myofibrils were occasionally stained. The plasma membrane was unlabeled. However, the plasma membrane was labeled when the rats had been injected with insulin (40 U/kg body wt) 15 min before perfusion fixation. In non-insulin-injected rats, the plasma membrane might show spotty staining close to clusters of intensely labeled subsarcolemmal vesicles. This may have been due to diffusion but may also indicate that there are domains of GLUT4 in the plasma membrane of nonstimulated fibers or that the endogenous insulin activity to some extent had translocated GLUT4 from the intracellular pool into the plasma membrane. Coated vesicles that were also labeled were found adjacent to subsarcolemmal vesicles and cisternae; it is possible that coated vesicles play a role during insulin- or contraction-induced translocation of GLUT4 between subsarcolemmal pool and plasma membrane. It has been proposed that glucose uptake into skeletal muscle fibers takes place across the t-tubule membrane rather than across the plasma membrane. This would explain the presence of GLUT4 at triadic junctions. Alternatively, we suggest that GLUT4 in t-tubules represents a second intracellular pool.

Animals↗
PubMed1991

Antidystrophin stains triadic junctions in regenerating rat muscles.

Dystrophin has biochemically been found in the sarcolemma and in junctional t-tubules, but immunocytochemistry shows reactivity at the sarcolemma only. In the present study, normal and regenerating soleus muscles of rat were perfused for 10 minutes with 2% formaldehyde; isolated fibers were stained with polyclonal antidystrophins and HRP and embedded in epoxy. Staining of triadic junctions in normal fibers was ambiguous but, in regenerated fibers, 4 weeks after injury it was distinct. Immature myotubes 3 days after injury showed reactivity at the sarcolemma and at various internal membranes. The nonselective staining of internal membranes may be due to secondary binding of the reaction product, and supports the view that dystrophin is cytoplasmic before it becomes restricted to the sarcolemma and t-tubules.

Animals↗
PubMed1990

Possible involvement of the retinoblastoma gene in undifferentiated sinonasal carcinoma.

Retinoblastoma tumor formation is initiated by the loss of function of both alleles of the RB-1 gene on chromosome 13. Patients with the hereditary form of retinoblastoma carry a germ line mutation at one of the two homologous gene loci in all cells and have an increased risk for nonocular tumors (mainly osteosarcoma and other mesenchymal tumors) in later life. The authors studied a 38-year-old patient with sinonasal undifferentiated carcinoma (SNUC) who had been treated for bilateral retinoblastoma by enucleation (left eye) and irradiation (right eye), respectively. Using molecular probes for the RB-1 gene and other loci on chromosome 13, the authors detected a deletion at the RB-1 locus in metastatic SNUC cells that was not present in normal tissue. These findings indicate that somatic mutations at RB-1 locus may be involved in the formation or progression of ectodermal tumors.

Adolescent↗