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Biomedical subjects

U Welsch

Publications and source records attributed to U Welsch.

At least 73 records · Page 4Linked to original sources
PubMed1993

Histological investigations on the thyroid glands of marine mammals (Phoca vitulina, Phocoena phocoena) and the possible implications of marine pollution.

In 1988 and 1989, thousands of harbor seals (Phoca vitulina) died in the North Sea from phocine distemper infection. The morphology of thyroid glands from 40 harbor seals found dead on the North Sea coastlines of Schleswig-Holstein, Federal Republic of Germany, during an epizootic of phocine distemper, was compared with the morphology of thyroid glands from five healthy harbor seals collected in Iceland. Thyroid glands from seven harbor porpoises (Phocoena phocoena) found dead in 1990 on the North Sea coastlines also were evaluated. Colloid depletion and fibrosis were found in the thyroid glands of harbor seals which died during the epizootic, but not in animals from Iceland. Thyroid glands of the porpoises showed similar lesions, but to a lesser degree, than those observed in the North Sea seals.

Animals↗
PubMed1993

[Cellularity and ultrastructural characteristics of human atherectomy specimens: comparison between restenosis and primary stenotic tissue of coronary and peripheral lesions].

Restenosis in patients treated by angioplasty is clinically and angiographically defined. The question remains to which extent each restenotic lesion can be attributed to residual plaque material and/or neointimal tissue formation post primary intervention. In an effort to reveal distinct anatomical characteristics which may allow conclusions to pathogenetic mechanisms involved in restenosis, histopathologic and electron microscopic examinations of human restenotic tissue were performed. To compare tissue samples from clinically restenotic lesions with those from untreated primary lesions for cell number and ultrastructural characteristics, a total of 64 percutaneously excised tissue specimens from coronary (n = 9) and femoral lesions (n = 18) of 27 patients treated by directional atherectomy were analyzed. Semiquantitative assessment of plaque slices for cell number (12 fields of view/lesion; magnification x500) revealed a spectrum of 11.7 to 35.3 cell nuclei/field of view (C/F) for clinical restenoses (n = 10) and of 0.9 to 28.2 C/F for primary lesions (n = 17). When comparing tissue specimens from restenotic origin with those of native lesions, there was a highly significant (p < 0.001) difference in cell number (ave: 22.2 +/- 7.1 versus 8.6 +/- 7.9 C/F; x +/- SD). Hypercellularity (mean cell density defined with > 20 C/F) was observed in 6/10 restenoses, hypocellularity (< 10 C/F) in 0/10 restenoses. For primary lesions, hypocellularity was found in 10/17 lesions, but hypercellularity in 2/17 lesions. Ultrastructural analysis of hypocellular lesions by transmission electron microscopy revealed large extracellular matrix fields with infrequently embedded smooth muscle cells (SMCs). These cells were characterized by a microfilament-rich intermediate phenotype, thereby indicating decreased metabolic activation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Ultrastructural and biochemical observations on proteoglycans and collagen in the mutable connective tissue of the feather star Antedon bifida (Echinodermata, Crinoidea).

Mutable connective tissue, unique to echinoderms, changes its mechanical behaviour within seconds of nervous stimulation. The molecular mechanism of this phenomenon is not understood. In this study proteoglycans and collagen of the brachial ligaments connecting neighbouring ossicles of the arms of the feather star Antedon bifida have been investigated by biochemistry, light and electron microscopy and the critical electrolyte concentration (CEC) technique using the dye Cupromeronic Blue (CB). The ligaments consist mainly of parallel cross-striated collagen fibrils, 82 +/- 12 nm in diameter, with a characteristic banding pattern and a D-period of 52.8 +/- 3.2 nm. Some fibrils were disaggregated into bundles of 10-11 nm protofibrils, lying between the normal fibrils. Proteoglycans occur at the surface of the fibrils with 2 binding sites (each with a different CEC) per D-period and also inside the fibrils. The surface proteoglycans are more highly sulphated (i.e. their CECs are > 1.3 M) than the intrafibrillar proteoglycans (CEC < 0.9 M). The glycosaminoglycans consist of a highly sulphated chondroitin sulphate, possibly with fucose residues. The results are consistent with the theory that disaggregation of the fibrils into protofibrils and reaggregation might be a mechanism of mutability, without excluding the possibility that fibrils may slide alongside each other during movements in the viscous phase of the ligament.

Animals↗
PubMed1992

Glycosaminoglycans and fibrillar collagen in Priapulida: a histo- and cytochemical study.

The distribution of glycosaminoglycans and fibrillar collagen was studied in various tissues of priapulids, which represent an ancient group of marine metazoa. Sulphated glycosaminoglycans, as demonstrated at the electron microscopical level by Cupromeronic blue, were predominantly found in the cuticle, in basement membranes and also in the narrow connective tissue space below epidermis and anterior intestine. On the basis of their morphology the Cupromeronic blue precipitates could be divided into several groups. Fibrillar collagen occurred in the connective tissue under the epidermis and the epithelium of the anterior intestine. The spatial interrelationship between fibrillar collagen and glycosaminoglycans lacked with some exceptions, the high regularity found in connective tissues of other invertebrates and of vertebrates. This might be related to the special skeletal system of priapulids, consisting mainly of a strong extracellular cuticle and the turgor of the fluid-filled body cavity. In such a system the usual supportive structures seem to be of less functional significance.

Animals↗
PubMed1992

Basic biochemical data on blood from antarctic Weddell seals (Leptonychotes weddelli): ions, lipids, enzymes, serum proteins and thyroid hormones.

1. Standard laboratory values of blood samples taken from Weddell seals in Antarctica were determined. 2. Numerous blood parameters are similar to those observed in man. 3. Comparatively high cholesterol levels but normal triglyceride levels were observed when compared with humans. 4. In comparison to laboratory findings in humans, T4 levels were decreased although T3 levels were normal. 5. The levels of alkaline phosphatase are considerably higher than those in humans. 6. The data obtained indicate different lipid and thyroid hormone metabolism in Weddell seals when compared with humans.

Animals↗
PubMed1992

Recovery of proteins from the broncho-alveolar lavage fluid proposal for a standardisation.

In this study various precipitation methods have been used to concentrate the proteins from broncho-alveolar-lavages. The highest percentage of proteins was recovered from the broncho-alveolar-lavages using the method of Wessel & Flügge (Anal. Biochem. 138 (1984) 141-143). The recovered proteins were further analysed by SDS-polyacrylamide gel electrophoresis. Except for low molecular mass proteins, the method of Wessel & Flügge proved to be the most effective for the recovery of individual proteins. In general, the method of Wessel & Flügge seems to be the superior method for concentrating proteins of broncho-alveolar-lavages for further analysis.

Bronchoalveolar Lavage Fluid↗
PubMed1992

[Growth-inhibiting effect of colchicine on cultured vascular wall myocytes from arteriosclerotic lesions].

Proliferative, migratory, and secretory activities of vascular smooth muscle cells are currently discussed as determinants of human plaque and restenosis formation. Affecting these determinants with drugs may promise anti-arteriosclerotic effects. Plaque tissue was removed from both coronary and peripheral lesions of a total of 18 patients to cultivate smooth muscle cells (SMC) for subsequent in vitro studies. The antitubulin colchicine (C) caused a concentration-dependent decrease of SMC proliferative activity with an IC50 of 5 x 10(-9) M. Migratory activity was analyzed by a standardized semi-automatic video system. This parameter was reduced by C in a concentration-dependent manner (IC50: 5 x 10(-10) M). As shown by immunofluorescence microscopy, the typical structure of microtubules of C-treated SMCs was distorted, whereas the pattern of alpha-actin filaments remained unaltered. Transmission electron microscopy (TEM) revealed that the number of microtubules was diminished after addition of C, and that a distinct disorganization of cytoplasmic organelles as well as the formation of vacuoles had occurred. In vitro studies of human smooth muscle cells derived from vascular plaques indicate that colchicine may be useful as an anti-arteriosclerotic drug, since a concentration-dependent concordant effect on proliferation, migration, and secretory processes of the SMC could be demonstrated.

Aged↗
PubMed1991

Similar frequency of autoantibodies against pneumocytes type II and Clara cells in patients with interstitial lung diseases and healthy persons.

Several experimental findings suggest an association between interstitial lung diseases and autoantibodies. Antibodies against lung tissue including pneumocytes type II in patients suffering from idiopathic pulmonary fibrosis (IPF) were reported in recent years. In this investigation the serum of 103 persons (10 with IPF, 23 with M. Boeck, 18 with rheumatoid arthritis (RA) and 52 healthy controls) was examined for autoantibodies against pneumocytes type II and Clara cells by indirect immunofluorescence on human lung tissue. These antibodies against both cell types are an additional proof for common antigens in pneumocytes type II and Clara cells. The autoantibodies were present in similar frequency in the 4 groups (IPF: 20%, M. Boeck: 26.1%, RA: 22.2% and 23.1% of the healthy controls). So no significant association was found between the antibodies and the interstitial lung diseases. A role of the antibodies in the pathogenesis of the diseases, however, can not be excluded by this study. A possible role as parameter of development of interstitial lung diseases should be subject to further investigations in form of a prospective follow up study.

Adult↗
PubMed1991

Lectin histochemistry of human bone marrow: investigation of trephine biopsy specimens in normal and reactive states and neoplastic disorders.

The lectin binding pattern of bone marrow cells in normal and reactive states and in various neoplastic disorders was investigated using trephine biopsy specimens taken from the iliac crest. The tissue samples were routinely processed (fixed in formalin and embedded in paraffin wax) and subjected to mild decalcification with EDTA. The following results were obtained. (1) More than half of the 23 fluoresceinated lectins used reacted with normal blood cells and/or their neoplastic derivatives. Inhibition tests with the appropriate sugars confirmed the specificity of binding for the majority, but not all, of the lectins. (2) WGA, Con A, PSA, STA and RCA60 and RCA120 produced a particularly intense reaction with normal, reactive and neoplastic myeloid cells. Erythroblasts exhibited weak staining in a few cases by a few lectins (WGA producing the strongest staining), while megakaryocytes nearly always remained unstained. Neoplastic lymphoid cells in various lymphoproliferative disorders and plasmacytoma cells generally reacted with the same lectins as the myeloid cells. (3) Since neoplastic myeloid cells in various myelodysplastic and myeloproliferative disorders exhibited a lectin binding pattern similar to that of myeloid cells in normal and reactive bone marrow, it is unlikely that lectin histochemistry of the bone marrow will prove of great value in the diagnosis of myelodysplastic-myeloproliferative disorders.

Blood Cells↗
PubMed1991

Lectin binding patterns of human tissue mast cells indicate marked phenotypical diversity.

Glycoconjugate expression by human tissue mast cells (MCs) from various sources (including lymph nodes with signs of chronic non-specific lymphadenitis, skin lesions of urticaria pigmentosa, and bone marrow infiltrates associated with systemic mastocytosis) was studied histochemically with a broad panel of fluorescein-labelled lectins. Of the 19 lectins applied, 11 (sugar specificities: fucose, N-acetylgalactosamine and neuraminic acid) did not stain any MCs, while 8 (sugar specificities: mannose, N-acetylglucosamine, and galactose) were found to bind to MCs. These lectins exhibited different binding patterns in various disease entities. Only a few of these 8 lectins (in particular, phythaemagglutinin-L) produced strong staining of the MCs in most or all of the cases. Some (e. g. phythemagglutinin-E) produced only weak staining, and this in only a few cases. The lectins used, however, did not distinguish between reactive and tumorous MCs. Although lectins are therefore unlikely to be of use in resolving problems of differential diagnosis concerning proliferation of MCs, our investigation has shown that tissue MCs exhibit marked phenotypical diversity with regard to their lectin-binding properties.

Biopsy↗
PubMed1991

Proteoglycans in the notochord sheath of lampreys.

The distribution of proteoglycans in the sheath and epithelial cells of the lamprey notochord had been studied using electron microscopy on material stained with the dye cupromeronic blue (CMB). CMB-precipitates, which indicate the presence of sulphated proteoglycans, were found in the inner collagenous but not the outer "elastica externa" regions of the notochord sheath. Precipitates were also found in the zone of the basement membrane of the notochord epithelial cells, in intercellular spaces within the notochord epithelium, and in intracellular spherical bodies of the epithelial cells. These results indicate that the proteoglycans in the notochord sheath are produced by the notochord cells. The combined presence of sulphated proteoglycans and collagen type II in the notochord sheath parallels the situation found in the cartilage of higher vertebrates.

Animals↗
PubMed1991

[Current status of directional coronary atherectomy in interventional cardiology].

Directional coronary atherectomy (DCA) was used in 74 patients with an average age of 56 years. They were categorized into three different groups depending on the indications for atherectomy. Group I included all patients who had atherectomy as their primary intervention (n = 26), because they were assumed to be unsuitable for PTCA. Group II consisted of patients in whom DCA was used after failed balloon dilatation with unsuccessful but uneventful treatment (n = 20). Group III (n = 28) included cases where DCA was performed as a "rescue" or "bail-out" procedure after failed PTCA resulted in critical ischemia (ECG changes, chest pain, hypotension, and shock). The target lesions were located in LM 2, LAD 52, RCA 16, ACVB 4. The mean length of lesion was 8 mm (2-25 mm). The overall success rate was 94%. The mean stenosis was reduced from 90.6 +/- 10% to 17.2 +/- 14.8% in cases with primary success. The presently available follow-up angiography (n = 31) showed six restenoses. Major complications occurred in seven cases (death: 0, myocardial infarction: 2, CABG within 24 h: 5). Histological analysis revealed highly cellular areal as a major characteristics of a coronary lesion and also of restenotic tissue. Tissue of the lamina elastica was present in 44% and of media in 14%. Thrombus was found only rarely. Ultrastructure showed a significant amount of extracellular matrix in the primary coronary lesions and isolated smooth muscle cells without gap-junctions. RER, mitochondria were typical for the synthesizing type of smooth muscle cell. In restenotic tissue a focal high density of smooth muscle cells with increased synthesizing activity and gap-junctions was present. Endothelial cells (and macrophages) were found only rarely. Furthermore, altered smooth muscle cells from restenotic tissue showed a significantly increased migration and proliferation. Our results show that DCA is a safe and effective technique that can extend the use of percutaneous procedures and provide a promising, nonsurgical option in cases of failed PTCA. Histological analysis revealed a proliferative process as a characteristics of restenosis development.

Angioplasty, Balloon, Coronary↗
PubMed1990

Histopathological findings in harbour seals (Phoca vitulina) found dead on the German North sea coast.

Various organs--lung, trachea, liver, kidney, heart, adrenal gland, skin, spleen, thymus, lymph node, gut, thyroid, spinal cord and brain--were removed from 43 seals at dissections performed on the German North sea coast. The specimens were fixed in formalin and routinely processed for light microscopy. The major pathological findings were Lung: acute congestion with interstitial and intra-alveolar oedema; intra-alveolar haemorrhage; suppurative bronchitis and bronchopneumonia; larvae and adult forms of Parafilaroides gymnurus. Liver: acute congestion; granulomatous lesions and infiltrates of eosinophils; intravascular nematodes. Spleen: varying degrees of atrophy of the white pulp; haemosiderosis; acute congestion of the red pulp. Lymph nodes: varying degrees of atrophy of the lymphatic tissue; long-standing sinus histiocytosis with partial fibrotic obliteration of the lumina; parasitic infiltration, sometimes with the Splendore-Hoeppli phenomenon; germinal centre hyperplasia. Thymus: pronounced atrophy of the lymphatic tissue, particularly in the cortical areas. Thyroid: marked reduction in colloid content. The other organs studied were normal or showed only minor histopathological changes. The morphological findings do not allow definite conclusions to be made about the aetiology and pathogenesis of the illness and death of the seals. However, evidence has been published that the seals' illness is probably due to canine distemper virus. The atrophy of the lymphoreticular tissues is consistent with infection by this virus.

Animals↗
PubMed1990

Ultrastructural localization of glycosaminoglycans in the human mammary gland.

The distribution of glycosaminoglycans (GAGs) in the human breast tissue has been studied at the EM-level by means of the dye Cupromeronic Blue and Scott's critical electrolyte concentration technique. There have been several reproducable localizations: 1. Orthogonally at the main bands of collagen fibrils (probably chondroitin/dermatan sulphate). 2. Large GAGs in areas, almost free of collagen and other fibrils (probably chondroitin sulphate). 3. In the basement membranes of capillaries and glandular epithelium (probably heparan sulphate). 4. Fine GAGs at the surface of the adipocytes (probably heparan sulphate). 5. In the heterogenous granules of mast cells (probably heparin).

Breast↗
PubMed1990

Ultrastructural and histochemical observations on secretory phenomena in the resting human mammary gland.

Ultrastructure and histochemistry of clinically normal appearing tissue and secretions of non-lactating human mammary glands have been investigated in order to document and analyse secretory phenomena in the resting gland. The material studied originated from women of different ages (18-74 years) who underwent plastic surgery or surgery for various disorders of the breast. The epithelia of small ducts and of alveolar enlargements as well as acini contained moderate amounts of mitochondria and of cisterns of the rough endoplasmic reticulum; the transcisterns of the Golgi apparatus which were surrounded by smooth and coated vesicles, exhibited modest dilatations, the number of lysosomes increased with age; regularly glycogen particles and bundles of intracellular filaments (phi 5 nm) were to be observed. Typical casein vesicles and stages of apocrine secretion of milk fat globules were not seen. The following features indicated secretory activity: differently sized vesicles and granules with flocculent, dense, or light contents were regularly to be seen in the apical cytoplasm often immediately below the apical plasma membrane of the epithelia of the small ducts and even more frequently in the alveolar enlargements. Secretory products of fine granular or filamentous structure, probably containing proteins, were frequently found within the lumen. Different types of lipid and liposome-like particles were detected both in intracellular localization as well as in ductal lumina. As demonstrated by lectin histochemistry the secretory products also contained a considerable amount of carbohydrate components. The composition of the secretory products of the resting gland is of clinical interest since the chronical deposition of secretions, which among others possibly contain enzymes producing oxygen radicals, may lead to pathological changes of mammary gland tissue.

Adult↗