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Biomedical subjects

W Beuche

Publications and source records attributed to W Beuche.

At least 37 records · Page 2Linked to original sources
PubMed1993

Reactivity of locally produced CSF antibodies in patients with neurosyphilis against antigens of Treponema pallidum.

The reactivity and specificity of locally produced cerebrospinal fluid (CSF) antibodies against antigens of Treponema pallidum were assessed by Western blotting in patients with clinical signs of parenchymal or meningovascular neurosyphilis. All nine patients showed local production of treponeme-specific antibodies in the central nervous system (CNS). In most of the patients serum and CSF antibodies were bound to the same antigens: the common treponemal 48/45 kDa protein and the putative specific T. pallidum protein in the range of 12-14 kDa. In some patients the intensity of staining obtained by CSF antibodies was higher than that derived from serum, indicating locally produced antibodies. In contrast to other more acute inflammatory CNS diseases, no expanded or different antigen binding of the CSF antibodies compared with serum antibodies was found in neurosyphilic patients. The results presented are discussed with regard to the role of the blood-brain barrier in antibody concentrations of CSF and serum.

Adult↗
PubMed1992

Specific antigen binding by activated cerebrospinal fluid B lymphocytes in acute neuroborreliosis.

A recently developed immunocytochemical antigen-binding sandwich test for the identification of specific activated B lymphocytes was applied to cerebrospinal fluid cells and peripheral blood mononuclear cells in patients with acute neuroborreliosis. Discrimination of antigen-binding phagocytes was achieved by double staining with monoclonal antibodies. Specific activated B lymphocytes were much more numerous in cerebrospinal fluid than in blood, showing great interindividual differences. When intrathecal immunoglobulin production was present, the number of specific activated B lymphocytes was also high. The specificity of all activated B lymphocytes ranged from 10% to 60% and was higher in the acute stage than after treatment.

Acute Disease↗
PubMed1991

Differential isolation of eosinophils and myelin phagocytes from mouse peripheral nerves during Wallerian degeneration by uncoated and immunoglobulin-coated sheep red blood cells.

Highly purified (less than 95%) eosinophilic granulocytes and myelin phagocytosing macrophages were isolated from enzyme digested mouse peripheral nervous tissue undergoing Wallerian degeneration by sequential centrifugation on Ficoll-Hypaque together with uncoated and immunoglobulin-coated sheep red blood cells. Isolation of eosinophils is a first step for further investigation of the role of these cells during Wallerian degeneration. Myelin phagocytes were found in the Fc receptor positive cell population, while undigested myelin and Schwann cells remained in the interphase.

Animals↗
PubMed1991

The proliferation rate of T and B lymphocytes in cerebrospinal fluid.

An immunocytochemical method is presented by which individual proliferating T and B lymphocytes can be detected in the cerebrospinal fluid (CSF) of patients with inflammatory and neoplastic diseases of the central nervous system. The absolute numbers of proliferating T and B lymphocytes were approximately equal, so that only a minority of the strongly prevailing T-cell population proliferates in the CSF during the immune process. The highest proliferation (25.7%) was found within the small subset of activated, i.e. cytoplasmic immunoglobulin-containing, B lymphocytes. This provides further evidence that these cells are not the terminally differentiated plasma cells of classical cytology but progenitor cells capable of further proliferation. B-cell lymphomas could be easily identified. The detection of abnormally proliferating cell subsets could help in the differentiation of opportunistic infection from leukaemic infiltration.

B-Lymphocytes↗
PubMed1989

Demonstration of zoster virus antibodies in cerebrospinal fluid cells.

A method is presented that allows the immunocytochemical detection of varicella zoster virus antigen-binding cerebrospinal fluid cells in zoster ganglionitis. Antigen-binding cells were found only in patients suffering from this disease. The technique is sensitive, specific, inexpensive and relatively fast, and is potentially applicable to other inflammatory central nervous system diseases with immunoglobulin-containing cells (ICC) in CSF. The detection of antigen-binding CSF cells may represent a very early diagnostic test comparable with the early IgM antibodies of the systemic immune response.

Antibodies, Viral↗
PubMed1988

The rate of Wallerian degeneration in the absence of immunoglobulins. A study in chick and mouse peripheral nerve.

Sciatic nerves undergoing Wallerian degeneration are subject to massive invasion by monocytes bearing Fc receptors. The present experiments were done to explore the potential role of the Fc receptors. The effect of suppressed immunoglobulin levels on the rate of Wallerian degeneration was studied in the n. medioulnaris of the chick and in murine sciatic nerve. In the avian model, total immunoglobulin production was eliminated by bursectomy. The mice were injected after birth with antibodies against IgM, causing a selective reduction of immunoglobulin M levels. Myelin degeneration was measured in both groups by computer-assisted line sampling and corrected for intrafascicular edema. In both models, there were only minor differences with the controls. Immunoglobulins, accordingly, do not seem to play a significant role in the efficiency of myelin phagocytosis by monocytes during Wallerian degeneration. The study also includes data on the degree and the distribution of edema in nerves undergoing Wallerian degeneration.

Animals↗
PubMed1986

Changes of myelin proteins during Wallerian degeneration in situ and in millipore diffusion chambers preventing active phagocytosis.

Changes of myelin proteins in mouse sciatic nerves were studied comparing nerves degenerating in situ with nerves enclosed in millipore diffusion chambers which eliminate invasion of non-resident cells. Nerves kept in chambers showed nearly complete preservation of myelin sheaths with a very slow degradation of myelin proteins. Nerves degenerating in situ showed rapid myelin phagocytosis by macrophages with almost complete disappearance of myelin proteins after 28 days. These data elucidate the role of macrophages for removal of myelin proteins.

Animals↗
PubMed1986

Myelin phagocytosis in Wallerian degeneration of peripheral nerves depends on silica-sensitive, bg/bg-negative and Fc-positive monocytes.

Previous experiments with nerves enclosed in millipore diffusion chambers had shown that myelin degradation during Wallerian degeneration depends on invasion by non-resident cells. The present study was aimed at a more precise identification of the invading cell population. Monoclonal antibody studies of degenerating nerves showed many cells with the Fc marker; cells having the Lyt-1, Lyt-2, Ia or Mac-1 markers were sparse or absent. Nerves transplanted into mice of the Chediak-Higashi bg/bg strain were invaded by cells lacking the bg/bg marker (giant lysosomes), while cotransplanted muscle tissue was invaded by cells with the bg/bg marker. Blocking monocytes with silica reduced both cell invasion and myelin degradation in degenerating nerves. These observations show that Wallerian degeneration of peripheral nerve fibers involves a subset of monocytes which are silica-sensitive and have Fc receptors but no bg/bg giant lysosomes.

Animals↗
PubMed1986

Remodelling of nerve structure in experimental isoniazid neuropathy in the rat.

The neuropathy caused by a single dose of isoniazid in rats was studied with a computer-assisted morphometric method. Scatter diagrams of the g ratio (quotient fibre diameter/axon diameter) define regenerating fibres as a distinct population, distinguishable from the surviving fibres by reduced sheath thickness and reduced axon calibre. There was also evidence of a subtle direct toxic effect on the entire fibre population, causing axon shrinkage masked by readjustment of the myelin sheath.

Animals↗
PubMed1986

Chronic enteral poisoning caused by potassium permanganate: a case report.

To our knowledge, this is the first case report of a multiple, low dosage ingestion of manganese. A 66-year-old male patient is presented, who ingested 125 ml of a 8% solution of potassium permanganate (10 g) within 4 weeks. As early as 2 weeks after the beginning of poisoning, psychological alterations were noted. Neurological examination revealed disturbances of many subsystems of the CNS. Visually evoked potentials showed prolongation of the P2-latency, not reported in earlier publications. Levels for manganese were elevated in peripheral blood as well as in hair samples. Treatment with calcium trisodium pentetate decreased serum levels and increased urine excretion of manganese. Nine months after poisoning, the first signs of progressive Parkinson disease became evident. The time-course of neurological symptoms seems to depend on a critical dose of manganese.

Aged↗
PubMed1985

A quantitative assessment of myelin sheaths in the peripheral nerves of dystrophic, quaking, and trembler mutants.

If myelin sheaths are relatively thin for axon caliber, this is generally taken as a sign of insufficient myelin formation. However, recent studies have shown that sheath thickness relates not only to axon caliber; the relative length of the internode is also important. Foreshortened internodes have slightly thinner sheaths than long internodes of the same fiber caliber (Friede and Bischhausen 1982). In the present study we compared sheath thickness with internode geometry in the sciatic fibers of three murine mutants, the Dystrophic, Quaking and Trembler mice, using a new computer-assisted method. A quantitative correspondence was found between abnormally thin sheaths and internode foreshortening. The magnitude of the changes was the same as that found previously in normal and regenerated fiber populations. The data show that the geometric proportions of internodes cannot be ignored when assessing sheath thickness, and they also shed some new light on the mechanisms which produce abnormally thin sheaths.

Animals↗
PubMed1985

Granular cell tumour in the third ventricle. Case report with histological, electron-microscopic, immunohistochemical and necropsy findings.

A rare granular cell tumour was found in the third ventricle of a 56-year-old woman. Histological and electron-microscopic features obtained from the biopsy material were identical to those of previously recorded cases. Immunohistochemical study demonstrated vimentin but not S-100 protein in the tumour cells. The possibility should be re-considered that granular cell tumours may have more than one cell of origin.

Cerebral Ventricle Neoplasms↗
PubMed1985

Millipore diffusion chambers allow dissociation of myelin phagocytosis by non-resident cells and of allogenic nerve graft rejection.

Allogenic graft rejection leads to rapid tissue destruction of nerves transplanted directly into a muscle lodge. If the nerves are enclosed in 5.0 micron pore chambers and transplanted into the peritoneal cavity, there is no allogenic graft rejection. The phagocytosis of myelin by invading cells is, however, not disturbed, showing that these cells can distinguish the degenerating myelin from the Schwann cell without being responsive to the Schwann cell's allotype. If the allografts are allowed to predegenerate for 4 wk in 0.22 micron pore chambers which do not admit any cells, there is a striking mitigation of the allogenic graft rejection if the nerves are subsequently released from the chamber. Myelin phagocytosis in such nerves is also reduced. These observations indicate the existence of a hierarchy of cellular recognition mechanisms involved in nerve tissue degradation. Phagocytosis of the myelin sheath by macrophages involves recognition mechanisms which differ from those of the allogenic rejection of the Schwann cell, presumably mediated by T lymphocytes.

Animals↗
PubMed1985

A new approach toward analyzing peripheral nerve fiber populations. I. Variance in sheath thickness corresponds to different geometric proportions of the internodes.

The thickness of the myelin sheath is known to increase with axon caliber, but there is also a superimposed, slight variation in sheath thickness depending on whether a fiber of a given caliber has very long or very short internodes. This relationship between myelin sheath thickness and the geometric proportion of the internode has been shown in subserial sections of isolated nerve fibers. It allows a prediction of sheath thickness from the quotient internode length/axon caliber, or conversely, a prediction of internode foreshortening from sheath thickness. We applied this new approach to the analysis of sciatic fiber populations of frogs, mice, rats and cats. The geometric proportions of these fibers were defined by the quotient internode length/fiber caliber. This quotient was compared with minor variation in sheath thickness as determined with a computer-assisted technique measuring large numbers of fibers in low-power electron micrographs. The method also calculated fiber shrinkage and recalculated all data for circular fiber profiles. The data obtained confirmed previous electron microscopic measurements showing that there is a slight reduction in sheath thickness when a fiber of a given caliber has relatively short internodes, and vice versa. A population of very thin, thinly myelinated fibers was also revealed. Sheath thickness and the geometric proportions of internodes in frogs differed markedly from those in mammals.

Animals↗
PubMed1985

A new approach toward analyzing peripheral nerve fiber populations. II. Foreshortening of regenerated internodes corresponds to reduced sheath thickness.

The new approach used in this study is based on the concept that axon caliber is not the only factor affecting the thickness of the myelin sheath. It is necessary to consider the entire geometric proportions of the internode, since sheath thickness corresponds to the relationship between axon caliber and the length of the internode. This type of analysis was applied to the regenerated internodes in rat sciatic nerves. Survival periods of 4, 9, 18 and 36 weeks were studied after lesions had been placed in young adult rats. The data show significantly thinner sheaths for regenerated fibers as compared with normal nerves, consistent with previous observations. This reduction in sheath thickness, however, corresponded quantitatively to the degree of foreshortening of internodes in the regenerated nerves. An average reduction of 10 in the quotient internode length/fiber caliber corresponded to a reduction of about 0.015 in the relative thickness of the sheath (quotient axon diameter/fiber diameter). This means that regenerated myelin sheaths are not truly hypoplastic; rather, they are adapted to the reduced internode length, and have the same relationship found for normal fibers. In partially damaged nerves there was a clear distinction in terms of sheath thickness between regenerated fibers and undamaged fibers. Demonstration of this phenomenon by scatter diagrams opens new possibilities for the quantitative assessment of neuropathies.

Animals↗
PubMed1985

Combined scatter diagrams of sheath thickness and fibre calibre in human sural nerves: changes with age and neuropathy.

A computer-assisted method permits collection of large numbers of measurements of fibre profiles in electron micrographs of human sural nerve biopsies. The method is based on simultaneous demonstration of fibre calibre and of sheath thickness in terms of the g-ratio (quotient axon diameter/fibre diameter), and on the recalculation of all parameters for circular fibre profiles. The fibres of small and large diameters of human sural nerves were found to form separate populations with distinctly different trends for sheath thickness and also different patterns of maturation. Preliminary data in neuropathy show that this method gives a better distinction of the extent of damage to either of the two populations; it also permits assessment of the number of regenerating or remyelinating fibres.

Adolescent↗
PubMed1984

The role of non-resident cells in Wallerian degeneration.

Wallerian degeneration was studied in the phrenic or sciatic nerves of mice following transplantation into Millipore diffusion chambers of 0.22 micron pore size which were implanted in the peritoneal cavity and kept for up to eight weeks. This method positively eliminates the access of nonresident cells to the tissue, at the same time providing proper conditions for tissue survival. Such nerves showed no proliferation of Schwann cells and no evidence for their active role in the removal or digestion of myelin. Schwann cells rejected their sheaths and the latter persisted for weeks, leading either to sheath distension (the sheath becoming wider and thinner) or to collapse (the sheath becoming thicker, collapsing upon the empty axis cylinder). The outer envelope of Schwann cytoplasm separated into pseudopodia rich in microtubules. Sheath rejection led to a slow decay of the myelin in the absence of active phagocytosis. There was profuse fibroblastic proliferation from the epineurium and perineurium, from which cells migrated into the chambers developing fatty change. No evidence was found to link the fatty change in fibroblasts to sheath decay. Diffusion chambers of 5.0 micron pore size were invaded by leukocytes and monocytes. Nerves kept in such chambers showed active phagocytosis of myelin leading to its removal, similar to Wallerian degeneration in situ. Phagocytes were shown to attack selectively the rejected myelin sheaths, distinguishing the latter from the surviving Schwann cells, even though both structures derive from the same cell. The activity of phagocytes in digesting myelin was mediated by a signal which diminished in intensity with time; there was very little active phagocytosis of myelin in nerves that had been predegenerated in 0.22 micron pore chambers. Various modifications of the experiment, including studies with co-cultured peritoneal macrophages or bone marrow, indicate a need for additional activating factors to induce myelin phagocytosis.

Animals↗