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Biomedical subjects

R Warzok

Publications and source records attributed to R Warzok.

At least 37 records · Page 2Linked to original sources
PubMed1990

Argyrophil and beta-endorphin immunoreactive cells in focal islet-cell adenomatosis and insulin-producing islet-cell adenomata.

Pancreatic tissue from 3 cases of hyperinsulinemic hypoglycemia was examined using histochemical and immunoperoxidase staining techniques. The insular lesions present were adenomatosis and insulin-producing islet-cell adenomata. The great majority of the islet parenchymal cells in these lesions were reactive with antibodies to pro-insulin, C-peptide, and insulin. A variable number of islet cells was found to react with beta-endorphin antiserum in all 3 cases, while the reaction with antiserum against the neural tissue marker antigen, S-100, was restricted to the cases with islet-cell adenoma. Argyrophil parenchymal cells were present in focal adenomatosis but almost absent in insulomata. These results suggest that various lesions of the endocrine pancreas causing hypoglycemia can be distinguished by means of specific histo- and immunocytochemical methods because of differences in the distribution of characteristic cellular antigens.

Adenoma↗
PubMed1990

[Malignant neurinoma of the suprascapular nerve].

Malignant neurinomas are rare. The clinical symptoms are determined by the location of the tumor and are uncharacteristic. Therefore, the case of an 27-year-old male patient is described who was operated on a malignant neurinoma of the suprascapular nerve. The treatment of choice is radical surgery. In addition, radiation and chemotherapy are indicated in some cases.

Amputation, Surgical↗
PubMed1990

[Pathomorphology of mucopolysaccharidoses].

Mucopolysaccharidoses are autosomal recessive or X-linked hereditary lysosomal storage diseases occurring to one in 10,000 to 16,000 births. The definitive diagnosis is based on the biochemical verification of the enzyme defect in cultured fibroblasts of amniotic fluid cells, in amniotic fluid, in chorionic biopsies and by determination of the urinary excretion of glycosaminoglycans. Morphological studies are of utmost importance both for genetic counselling and enlightenment of the pathogenesis. In recent years, numerous reports appeared dealing with morphological changes in different types of mucopolysaccharidoses. Based on own studies in pre- and postnatal cases, the present paper gives an update review on light and electron microscopic peculiarities of the different types and subtypes of mucopolysaccharidoses according to the classification of MCKUSICK and NEUFELD (1983). Lysosomal storage is found in practically all organs. However, there are quantitative and qualitative differences which are responsible for variations in clinical symptomatology. The purpose of this paper is to describe these differences with particular emphasis on changes in various tissues, on the pathogenetic mechanism of the storage as well as on pre- and postnatal morphological diagnostics.

Brain↗
PubMed1990

[Systematic classification of the disorders of the peripheral nervous system].

Classification of disorders in the peripheral nervous system has been a controversially disputed subject. A brief account, therefore, is given of basic definitions and main groups of mononeuropathies and polyneuropathies. The most common types of mononeuropathies as well as hereditary and acquired polyneuropathies are listed in four tables. Particular attention is given to toxic neuropathies.

Humans↗
PubMed1990

[Morphological diagnosis of peripheral nervous system diseases].

Peripheral neuropathies are among the most common neurological diseases. Various tissues are available for morphological investigation, depending on the purpose of diagnosis. The sural nerve is most frequently used for nerve biopsy. The nomenclature of neuropathies is described together with prerequisites and techniques for nerve biopsy. Morphologically, a distinction can be made between parenchymatous and interstitial lesions. An account is given of the most important morphological patterns, such as axonal and neuronal degeneration and regeneration, including Waller's degeneration, segmental demyelinisation and remyelinisation as well as hypertrophic alterations. Brief reference is made to conjunctival, dermal, and rectal biopsies.

Biopsy↗
PubMed1990

[The nosological situation of hereditary motor and sensory neuropathies (HMSN, Charcot-Marie-Tooth disease, neural muscular atrophy)].

Hereditary motor and sensory neuropathies (HMSN) comprise a heterogeneous group of disorders. Since phenotypic manifestations are similar in most families, classification is based on differences in the mode of inheritance, onset and progression of the disease, nerve conduction velocity and nerve biopsy findings. Autosomal dominant, autosomal recessive, X-dominant and X-recessive forms, substantial intrafamilial differences, intermediate forms and the combination of neuropathies with spinocerebellar degeneration within one and the same sibship have been described. On the basis of selected own cases it is demonstrated that there is a broad spectrum of functional and structural abnormalities depending on the progression of the disease and on the site of nerve studied (proximal or distal part). Both the neuronal and hypertrophic variants begin with axonal degeneration of the dying back type followed by segmental demyelination and variable degrees of hypertrophic Schwann cell proliferation. Constantly, posterior columns of the spinal cord reveal fiber loss. Since the molecular basis of the different forms remains to be clarified it seems to be of greater interest to underline common features than to separate seemingly different nosological entities. It is suggested that the latter are partly the result of a selection of cases with a variable severity. Evidently, the syndrome of myatrophic ataxia comprises apart from "pure" HMSN with unsignificant degenerations of posterior columns and "pure" Friedreich's ataxia with mild peripheral nerve fiber loss intermediate forms.

Adult↗
PubMed1990

[Fully-automatic microscopic image analysis and measuring of single fiber conduction velocity in the sural nerve of short-term diabetic rats].

Contrasting to the usual measurement of nerve conduction velocity, which only determines the conduction of the fastest fibers, single fiber measurement allows the registration of the conduction velocity of different fiber classes. The present experiment was performed to study whether electroneurophysiological and/or morphometrical parameters of group II fibers have changed after shortterm diabetes mellitus. Diabetes was induced in 28-d-old Lewis 1A-rats by administration of 60 mg/KG b.w. Streptozotocin. 60 d later, with the aid of an oscilloscope VKS 22-16 (VUKO Elektronische Geräte GmbH, Mühlheim) single fiber measurements were performed. Morphometry was carried out on semithin transverse sections of sural nerve with an automatic image analysis system A6471-AMBA/R (Robotron, Dresden). The mean plasma glucose level of diabetic animals was 27.1 +/- 2.7 mmol/l. The mean afferent conduction velocity was significantly reduced in diabetic animals. Furthermore, efferent fibers could be verified in sural nerve which showed also reduced conduction velocity in diabetic rats. Morphometry revealed significant reduction of thickness and area of myelin sheaths, whereas area of axons remained unchanged. Electroneurophysiological and morphometrical changes will be discussed with special emphasis to different fiber groups. It is suggested, that primary Schwann cell lesion is responsible for the observed findings.

Animals↗
PubMed1990

[Automatic microscopic image analysis of semithin sections of peripheral nerves using the program Image-C/Nerve-Neuropathy].

Visiomanual morphometric analysis of peripheral nerve fibres has proved to be error-laden and inadequate. An automatic interactive programme was, therefore, developed for microscopic image analysis and feature extraction. Contours of myelin sheaths were properly identifiable, but an interactive programme component was found to be required to measure the remainder of two to 5% of fibres. Image analysis is shown to generate descriptive statistical features.

Humans↗
PubMed1989

[The peripheral nerves of non-diabetic rats after streptozotocin administration using automatic microscopic image analysis].

Electrophysiologic studies of posterior tibial nerves by averaging method and morphometric investigations of sural nerves by automatic image analysis were performed in 7 non-diabetic rats 42 d after the administration of 55 mg streptozotocin/kg b.w. and in 10 untreated controls. Morphometry of stained semithin sections was carried out with system A 6471-AMBA/R (Robotron, Dresden, G.D.R.). There was no decrease of motor nerve conduction velocity in streptozotocin injected animals. The investigated morphometric parameters showed no significant alterations in the streptozotocin group. The studies show that in streptozotocin diabetic rats electrophysiological and morphological alterations of the peripheral nerve are caused by hyperglycemia but not by direct neurotoxic effects of streptozotocin.

Animals↗
PubMed1989

[Morphometric studies of peripheral nerves and spinal ganglion cells in streptozotocin diabetic rats].

Morphometric studies of sural nerves and dorsal root ganglia cells L5 were performed in 8 diabetic rats 35 or 44d after the administration of streptozotocin and in 8 controls. Morphometry of photographed semithin sections was realized after whole body glutaraldehyde perfusion with semiautomatic MOP AM 02 and MOP Videoplan. The peripheral nerve showed no decrease of the total nerve area, number of nerve fibres or of myelinated area. Parameters area of fibres decreased in diabetic animals caused by reduction of myelin sheath thickness. There were no changes of mean neuron volume and maximal cell diameter in the dorsal root ganglia. Whereas in experimental short-term diabetes the peripheral nerves demonstrate morphologic changes correlating to biochemical abnormalities, no such correlations can be observed in the perikarya. It is suggested, that primary SCHWANN cell lesion is responsible for the observed myelin thickness reduction.

Animals↗
PubMed1988

[Ileus of the small intestine caused by intestinal anisakiasis (herring worm disease)].

Two cases of anisaciasis caused by eating of improperly prepared herrings which were infested with larval nematodes are reported. The acute type with a stenosing process in the small intestinal wall existed in both cases which resulted in an ileus. Therapy was resection of the affected intestinal part with end-to-end-anastomosis. The morphological proof of larval nematodes, which penetrate from lumen into the eosinophilic granulomata, pseudotumours and eosinophilic microabscesses are important histological findings. It should be considered the possibility of a herring worm disease in the case of an acute abdomen caused by an inflammatory small bowel stenosis.

Adult↗
PubMed1987

[Experimental diabetic neuropathy. Morphometric studies of spinal ganglia cells in short-term streptozotocin-induced diabetes].

Ganglion cells of both the left and right dorsal root ganglia L5 were investigated morphometrically in 8 diabetic rats 35 or 44 d after the administration of streptozotocin, as well as in 8 controls. The quantitative study included the analysis of mean neuron volume, maximal cell diameter, cell number per volume, by cell size class and the analysis of histograms. There were no changes in cell size. Whereas in experimental short-term diabetes the peripheral nerves demonstrate morphologic changes correlating to the biochemical abnormalities (reduced amino-acid uptake, decreased activity of Na+, K+-ATPase) no such correlations can be observed in the perikarya.

Amino Acids↗
PubMed1987

[The relation between melorheostosis and tumors].

Melorheostosis was diagnosed in a 13 year old female. Two years later an x-ray of the skull showed an calcified intracerebral mass. At the age of 18 years the patient died. The autopsy confirmed the diagnosis of melorheostosis and revealed a meningioma of falx cerebri in close proximity to predominantly intraventricular calcified tissue. A neurinoma of the left acoustic nerve was also found. In the literature melorheostosis has been anecdotally described in combination with nevi, hemangiomas, pelvic lipoma, lipoma of the spinal cord, chondrofibromas of the median nerve, tuberous sclerosis and neurofibromatosis. The nature of the relationship between melorheostosis and neoplasms has not been clarified. Those observations as well as the present report indicate an increased frequency of tumors (particularly of the nervous system) in patients with melorheostosis.

Adolescent↗
PubMed1987

[Morphology of diabetic neuropathy].

The morphological findings in peripheral nerves in diabetic subjects are reviewed. Diabetes is probably the most frequent cause of neuropathy. However it does not constitute a single nosological entity but is comprised of a variety of clinical and morphological changes. These are considered to be the consequences of metabolic derangements resulting from chronic hyperglycemia. Distal symmetrical neuropathies, which are most common, are characterized by axonal degeneration and segmental demyelination with loss of nerve fibres and fibrosis. Remyelination and axonal sprouting occur. Microvascular changes consist of thickening and hyalinization of the walls of the vessels. On electron microscopy these vessels appear thickened and show reduplication of the basal lamina that surrounds the endothelial cells and pericytes. The morphological bases of proximal symmetrical motor neuropathy, as well as of focal and multifocal neuropathies are briefly described. The synopsis of current knowledge can be helpful in diagnosis and differential diagnosis of disorders of the peripheral nervous system.

Axons↗
PubMed1986

[Experimental diabetic neuropathy. Morphometric studies on the rat N. suralis in short-term streptozotocin-induced diabetes].

Morphometric studies of sural nerves were performed in diabetic rats 35 or 44 d, respectively, after the administration of 60 mg/kg b.w. streptozotocin. Morphometry of photographed semithin sections was performed after whole-body glutaraldehyde perfusion both with the semiautomatic MOP Videoplan and the MOP AM 02 (Kontron, Munich, F.R.G.). The following parameters were registered: Area of nerves and fibers, perimeter of fibers, diameter of axons, thickness of myelin sheaths, form factor. No decrease of the total nerve area or of the myelinated area were found. Parameters area of fibers, thickness of myelin sheath and form factor decreased in diabetic animals. Axon diameter, ratio axon diameter-myelin sheath thickness and perimeter of fibers increased in the diabetic nerves. It is suggested that primary Schwann cell lesion is responsible for the observed myelin reduction.

Animals↗