Biomedical subjects

W Linss

Publications and source records attributed to W Linss.

At least 19 recordsLinked to original sources

PubMed1997

2-Acetylaminofluorene-produced selective cytotoxic damage of a ductal compartment and its repair in the submandibular gland of rats.

Salivary glands of rodents are rarely affected with spontaneous and induced malignancies. This may be linked with low physiologic cell renewal and the infrequency of cytolethal actions by xenobiotics. The genotoxic 2-acetylaminofluorene, carcinogenic for other organs, causes acute damage in salivary ducts. In the submandibular glands the damage is limited to the granulated convoluted tubules. They produce and release regulatory peptides including epidermal growth factor and nerve growth factor. The partial chemical sialoadenectomy is repaired by sequential cell proliferation in the basal cell layer of interlobular ducts and in dilated intralobular ducts (day 4 and 6), in intermediate duct-like structures (day 6 and 8), and lastly in acini (day 8 and 12). This is associated with a transient loss of structural characteristics of striated ducts and acini (up to day 6) and of the immunoreactivity for S-100 protein (up to day 4). Actin immunoreactivity at the acinar base is increased from day 6 to 20. Analogous to the late postnatal differentiation of the granulated convoluted tubules, their structural characteristics and immunoreactivity for epidermal growth factor do not recover within 20 days. The acute lesion of the endocrine ductal segment is suggested to be causally involved with other systemic effects following treatment with 2-acetylaminofluorene. First, hypophagia with loss of body, liver and thymus weight may result from disturbed saliva production. Second, previous studies have shown a mitotic burst of the biliary epithelium and bloodborne lymphocyte-stimulating activities. Either effect could be brought about by regulatory peptides (see above), probably after elevated circulatory release from necrotic granulated convoluted tubules.

2-Acetylaminofluorene↗

PubMed1997

Flow cytometric analysis of band 3 protein of human erythrocytes.

Flow cytometry was used to quantify the transmembrane anion exchanger (band 3 protein) of human erythrocytes by covalently bound eosin-5-maleimide. In vitro and in vivo vesiculated red blood cells were investigated. The fluorescence and light scatter signals of cells after heat induced vesiculation, in vivo ageing, and in patients with hereditary spherocytosis were decreased. These results reflect a deficiency of band 3 protein which is presumably caused by membrane surface area loss. It was possible to distinguish control erythrocytes, erythrocytes from patients with hereditary spherocytosis, and from other forms of haemolytic anaemias on the basis of their light scatter and fluorescence signals characteristics.

Anion Exchange Protein 1, Erythrocyte↗

PubMed1994

Anatomic bases of the forearm compartment syndrome.

One of the most common sites for the compartment syndrome (CS) is the forearm. Its compartments have been studied by injection of colored gelatin into the particular anatomical spaces. The three "pressure-measuring-points" recommended in the clinical literature to measure intracompartmental tissue pressure in equivocal diagnostic cases were used for the dye injections on the forearms of five preserved cadavers of adults. However, instead of the compartments especially affected in CS two adjacent spaces were revealed. In order to elucidate the clinical relevant spaces two additional approaches for the injection had been used. Cross-sections at 15 mm intervals of the injected forearms had been performed. Some of them are presented and schematically summarized in this article. Recent studies have suggested that there are different guidelines for description of the anatomically isolated spaces. However, especially one of these spaces seems to be responsible for the CS on the forearm. The remarkable features of this so called "deep flexor compartment" are its very restrictive envelopes, its rare fascial contacts, its impermeable seal in proximal-radial direction as well as the extremely endangered structures within the compartment. The flexor carpi ulnaris muscle is recommended to be the "primary structure" for measuring the tissue pressure as well as for surgical decompression. The article reviews the anatomical base of the CS.

Adult↗

PubMed1994

pH-induced denaturation of spectrin changes the interaction of membrane proteins in erythrocyte ghosts. Biochemical and electron microscopic evidence.

The influence of different buffer pH values on the properties of spectrin in erythrocyte ghosts and on isolated spectrin was investigated. Ultrastructural findings and the results of biochemical studies show that denaturation and aggregation of spectrin molecules rather than disulfide crosslinking are responsible for the precipitation of spectrin in acidic buffer. Since hemolysis in hypotonic buffer at pH 6.0 yields ghosts with spicules and microvesicles, the structure of spectrin in intact cells might also be changed and lead to the clustering of transmembrane proteins and the aggregation of components of the cytoplasmic network.

4-Chloromercuribenzenesulfonate↗

PubMed1994

Bay Y 3118, a new quinolone derivative, rapidly eradicates Listeria monocytogenes from infected mice and L929 cells.

Bay Y 3118 is a new quinolone derivative with pronounced activity against gram-positive bacteria including the facultatively intracellular bacterium Listeria monocytogenes. Bay Y 3118 was tested in vitro and in animal models of listeriosis. All strains of L. monocytogenes and other Listeria spp. were highly susceptible in vitro; the MICs for these organisms ranged from 0.062 to 0.25 micrograms/ml. Bay Y 3118 was rapidly bactericidal in vitro, with a postantibiotic effect occurring for 3 h after removal of the antibiotic. L. monocytogenes was eliminated from infected L929 cells treated with Bay Y 3118, suggesting a bactericidal effect on the listeriae in these cells. Immunocompetent mice were rapidly cured by treatment with 4 mg every 12 h. Concomitantly, the levels of interleukin 6 and gamma interferon in mouse sera declined rapidly. In immunocompetent mice, treatment with 2 mg of Bay Y 3118 every 12 h resulted in a greater initial reduction in the listerial counts in the organs than treatment with 2 mg of ampicillin every 12 h. Bay Y 3118 completely eliminated L. monocytogenes from the livers and spleens of chronically infected nude mice. However, some of the bacteria reappeared after the cessation of therapy. In conclusion, Bay Y 3118 is an excellent candidate substance for the therapy of infections caused by facultatively intracellular gram-positive bacteria such as L. monocytogenes.

Ampicillin↗

PubMed1994

A variant of a slam freezing device for electron microscopy.

A home-made slam freezing device is presented that allows reproducible results in freezing various unfixed tissues. The heart of the device is an aluminum socket, which harbors a plunger that is set in motion by a spring. At the end of the plunger there is an electromagnet which holds the sample on a sheet metal planchette. During stop freezing the electrical contacts are interrupted and the plunger can be withdrawn leaving the specimen on the cooled copper block. This guarantees freezing of not only solid tissues, but also cell suspensions, such as blood or bone marrow.

Animals↗

PubMed1994

Is the brush border membrane of the intestinal mucosa a generator of "chymosomes"?

1. The microvilli of enterocytes in calf intestine demonstrate high levels of vesiculation activity at the top and at the basal region. 2. The morphology of the vesicles associated with microvilli (100-500 nm diameter, unilamellar, few intramembraneous particles, high AP activity) is very similar to the morphology of vesicles found in the chyme. 3. Vesicles can be purified 6-10 fold from chyme of the calf intestine applying a Mg(++)-precipitation method, used for brush border membrane preparation. 4. Specific activities of alkaline phosphatase and disaccharidases were found to be much higher in chyme vesicles than in the mucosa. 5. Phospholipid content and phospholipid composition is in chyme vesicles different from brush border membrane vesicles. 6. The characterized chyme vesicles are referred to as chymosomes. We consider the mucosa as a large-scale generator of chymosomes, i.e. digestive enzymes bearing vesicles.

Alkaline Phosphatase↗

PubMed1994

Dysmorphic erythrocytes in glomerulonephritis. 1. Electron microscopical and histochemical investigation.

Dysmorphic erythrocyte malformation in urine is characteristic of glomerulonephritis. The mechanisms leading to this phenomenon are still unknown. To obtain evidence of the site as well as of the process of erythrocyte damage, electron microscopical and histochemical investigations of renal biopsy materials from 19 patients with histologically defined glomerulonephritis were performed. The results suggest that the initial damage of erythrocytes in the glomerular area is reasoned by enzymatic glycocalyx destruction. On passage through the tubular system the osmotically sensitized surface altered cells undergo rapid hemolysis and losses of membrane skeletal proteins leading to dysmorphic shape transformations.

Adult↗

PubMed1993

Evaluation of experimentally induced enzymatic alterations on the erythrocyte membrane by use of alcian blue.

The binding of the polycationic dye alcian blue to erythrocytes is investigated at pH 6 and pH 3 after treatment with neuraminidase and proteolytic enzymes. The portion of the dye bound by membrane-negative charge-carriers, as well as by hydrophobic interactions with mainly membrane protein compounds, is calculated. It is demonstrated that not only the sialic acid, as the main negative charge domain, but also proteins are interacting with the dyestuff. Proteolytically split membrane fragments contain a considerable amount of alcian blut that cannot be associated with the estimated sialic acid content.

Alcian Blue↗

PubMed1992

[The occurrence of aluminum-containing lysosomes in the kidney of experimentally treated rats].

Aluminium was detected by electron spectroscopic imaging and electron energy loss spectra in the lysosomes of all cell types of the nephron in rats treated with aluminium chloride after 5/6 nephrectomy. The lysosomes of kidney cells of untreated rats did not demonstrate any detectable amounts of aluminium. Electron energy loss spectra showed the regular occurrence of iron (and also other elements) in the lysosomes of both groups of rats.

Aluminum↗

PubMed1991

Phagocytosis activity of polymorphonuclear cells of normal persons and dialysis patients is influenced by different dialysis membranes.

Leukocyte (PMN) functional capacity has been investigated through evaluation of phagocytosis of opsonised yeast cells in a radiometric test system. The PMN of dialysis patients (DP) had a slightly lower ability to ingest opsonised yeast cells in comparison with normal persons (NP), suggesting that an intrinsic cellular defect may exist. Under the influence of six membranes (cellulose acetate, regenerated cellulose, modified cellulose, cuprophane, polysulphone, and polymethylmethacrylate) the phagocytosis index decreased significantly between 10 and 17% in NP and between 13 and 23% in DP. There is a clear correlation with the membrane surface area. These results are not explained by the number of dead leukocytes (4-6.5% in DP and also in NP independently of membrane contact). The direct membrane effect could be responsible for the diminished phagocytic activity of leukocytes in NP and DP. Aqueous extracts of membranes alone resulted in no change of the phagocytic ability of PMN. Extracellular or 'uraemic factors' were excluded by the test procedure. The killing rate of yeast cells by PMN in NP and DP was not influenced in any of the membranes tested.

Adult↗

PubMed1991

[How thick is the glycocalyx of human erythrocytes?].

The aim of the experiment was to determine the thickness of the glycocalyx of human erythrocytes of the blood group A. For that purpose, the distance between the electron dense contrasted lipid layer of the plasmalemma and gold sol particles loaded with Helix pomatia lectin was determined. The mean thickness of the glycocalyx under this conditions was 5.9 nm.

Antibodies↗

PubMed1991

[New aspects of the ontogenetic development of the human colon].

The parts of the fetal colon--later retroperitoneally located (ascending and descending colon)--were examined in 31 human fetuses in order to determine their ontogenetic formation, position, and dorsal attachment. The present data cast doubt upon so-called "descending of the caecum" described in current textbooks of embryology. Considering the literature available a new concept of the formation of the right colon flexure and the ascending colon is presented.

Cecum↗

PubMed1991

[Clinico-anatomic study for constructing pedicled myocutaneous trapezius flaps].

The authors investigated musculocutaneous flaps, paying particular attention to vascular anatomy, the development and length of their main vessels, their potential arc of transposition. Beyond that, their applications for soft tissue coverage in the head and neck region and procedures for coverage of the donor site were studied. When compared with the literature, the results show that pedicled musculocutaneous and osteomusculocutaneous trapezius flaps are especially suited for reconstructive surgery of the head and neck.

Aged↗

PubMed1990

The binding of a polyclonal antibody against human band 3 to in vitro aged erythrocytes.

In vitro aged human erythrocytes were checked for their anti-band-3-antibody loading by means of a protein A-gold technique. The in vitro-ageing procedures are introduced as an alternative to the questionable preparation of in vivo aged cells. They include the influences of NaF in various concentrations, of heat (49 degrees C) and urea. After the treatment with 20 mmol/l NaF and more, the IgG loading increases significantly. In contrast to that, however, exovesiculation induced by heat and urea lower the IgG loading. Possible mechanisms for the growing accessibility of the epitopes concerned are discussed in connection with changes occurring during the physiological ageing processes.

Anion Exchange Protein 1, Erythrocyte↗

PubMed1990

[Does induced Heinz body formation lead to the liberation of IgG receptors on the erythrocyte membrane?].

Immunofluorescence microscopical and biochemical studies led other authors to the conclusion that the formation of membrane-bound Heinz bodies at these parts of the plasmalemma of erythrocytes leads to clustering of band 3-protein and increased binding of IgG. We failed to detect immunocytochemically an increased IgG binding over phenylhydrazine induced membrane-bound Heinz bodies in otherwise intact erythrocytes using transmission electronmicroscopy and we also did not notice any clustering of intramembraneous particles over the numerous Heinz bodies by means of freeze etching. Especially at higher phenylhydrazine concentrations the erythrocytes show formation of vesicles and hemolysis accompanied by increased IgG binding and clustering of the intramembraneous particles. Photographs of such cells obtained by immunofluorescence microscopy are very similar to the pictures known from the literature.

Anion Exchange Protein 1, Erythrocyte↗

PubMed1990

Influence of membranes on generation of beta 2 M and release of leukocyte lysosomal enzymes.

Normal leukocyte functional capacity was investigated by evaluation of phagocytosis of opsonised yeast cells in a radiometric test system. After incubation with dialysis membranes (different cellulosic membranes, polysulfon membrane (PS), polymethylmetacrylate membrane (PMMN), the phagocytosis index, expressed as percent decrease with respect to initial values without membrane, decreased by 10%-25%. The most pronounced effect was observed with PS, cuprophane, modified cellulose and PMMA. The results are not related to differences in the viability of PMN during the test procedure; dead PMN amounted to about 4-6.5%. A significant increase in beta-NAG and beta-Gluc activities was released in the supernatants of the phagocytosis suspensions. This increase activity can be explained by the phagocytosis of PMN but it was not influenced by membrane contact. There was no influence of membrane contact or phagocytosis activity of PMN on the beta 2 M concentration in the supernatant demonstrating that no in vitro generation during incubation with either membrane exists.

Acetylglucosaminidase↗

PubMed1990

[Anatomic studies of the availability of the transverse cervical artery as the stem vessel of pedicled myocutaneous flaps in plastic surgery].

The course and the circulation area of the A. transversa colli were characterized preparatorically as well as with the help of injections of stains and angiographically with contrast media in corpses. Predictions concerning the formation of the angiosomes and thus the size and the shape of musculocutaneous trapezius flaps were derived from the investigations. The presentation of the specific topographic relations of the A. and V. transversa colli revealed indications concerning the formation of the vascular pedicle and thus the possibilities to transpose the musculocutaneous flaps in order to cover skin defects of the head, neck and thorax after extensive surgical intervention.

Aged↗