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Biomedical subjects

W Linss

Publications and source records attributed to W Linss.

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

[The nerve entry into the human femoral quadriceps muscle].

Taking into account differing results about the distribution velocity of excitation processes in muscles after nerve stimulation we intended to prepare those branches of N. femoralis that were in close topographical relation to the caputs of M. quadriceps femoris. For reasons of interindividual comparability and of the possibility of studies in living human beings we decided to express the estimated "real entry height" as part of the total distance between Spina iliaca anterior superior and the proximal margin of the patella. In case of entering several nerve branches the same muscle the distance between the almost proximal and the almost distal branch was defined as the area of nerve entry. Our results give reason to suppose that there are great individual differences in the spatial organisation of innervation zones (motoric endplates). To further strengthen this idea investigation about the intramuscular route of the nerves as well as selective staining of motoric endplates are indispensable necessary.

Femoral Nerve↗
PubMed1989

[Structure and function of human erythrocyte membrane skeletons].

On the basis of extensive studies of the literature and of own results the present knowledge about the structure of the membrane skeleton of human erythrocytes is summarized and functional and clinical aspects are described. The spectrins are the centre of interest. Their interconnections, spatial arrangement and association with other components of the membrane are explained in greater detail. With regard to the membrane skeleton questions of erythrocyte shape, membrane integrity, phospholipid asymmetry, distribution of transmembrane proteins and cell deformation are discussed.

Blood Proteins↗
PubMed1989

[The characterization of phagocytotic processes using morphometry].

In electromicroscopic pictures, the percentage areas of erythrophagosomes in macrophages of the spleen were determined 2 and 5 h after application of diamide and iodoacetate treated erythrocytes. The increase in erythrophagosomes is significant if compared with controls. It is mainly seen in connection with the changes of the erythrocyte membrane caused by diamide and iodoacetate which lead to an increased IgG-binding to the erythrocyte surfaces. The overcritical IgG-load acts as an phagocytosis signal for the macrophages.

Animals↗
PubMed1989

[The effect of chronic aluminum loading on lysosomal enzymes in serum and organ homogenates. Methodologic aspects].

The influence of aluminium administration both on the lysosomes and on the activity of DNA-dependent enzymes in rats with intact kidney function or following partial nephrectomy was investigated. The elevation in free N-acetyl-beta-D-glucosaminidase in connection with a decrease of latent beta-NAG-level in liver, spleen and kidneys may be supposed a dose dependent aluminium damage of the lysosomes. Moreover, the decrease of free and total beta-glucuronidase in the liver and spleen could be caused by a selective inhibition of synthesis of this enzyme.

Acetylglucosamine↗
PubMed1988

New, improved lanthanide-based methods for the ultrastructural localization of acid and alkaline phosphatase activity.

New, improved techniques for the ultrastructural localization of acid and alkaline phosphatase activity using lanthanide cations as the trapping agent were developed. Delayed penetration of the capture ions and the incubation constituents into cellular compartments was prevented by pretreating specimens with borohydride/saponin. Both the concentration of the capture agent in the incubation medium and the incubation time of the tissue specimens were optimized to achieve a satisfactory cytochemical reaction and to avoid precipitation artefacts caused by local matrix effects. The conversion of cerium phosphate into the almost insoluble cerium fluoride minimized losses of the reaction product during postincubation processing. Moreover, lanthanum itself as well as lanthanides other than cerium, e.g., gadolinium and didymium (praseodymium, neodymium), were successfully applied and can be recommended as capture agents for phosphatase cytochemistry.

Acid Phosphatase↗
PubMed1988

[Ultrahistochemical demonstration of blood group B substances on human erythrocytes with a lectin from Salmo gairdneri RICH].

From the roe of Salmo gairdneri RICH., a lectin was isolated which agglutinates specifically human erythrocytes of blood group B. For cytochemical labelling of the blood group substance B on the surface of human erythrocytes, an indirect approach was chosen. By means of a polyclonal antibody from the rabbit against the B-specific fish lectin, electronmicroscopic presentation was performed with Protein A gold using a multistep method. For quantification gold labelling was partially followed by a silver technique.

ABO Blood-Group System↗
PubMed1987

Aluminium induced damage of the lysosomes in the liver, spleen and kidneys of rats.

The influence of repeated aluminium (Al) administration (0.05 or 0.5 mg 100 g-1 b.w.t. i.p. 5 times weekly for 12 weeks) on the lysosomal enzymes N-acetyl-beta-D-glucosaminidase (beta-NAG) and beta-glucuronidase (beta-Gluc) in serum, liver, spleen and kidneys of adult female rats with intact kidneys, (NR), or following partial nephrectomy (5/6 NX) was investigated. After A1 loading, at the high dose only, the beta-NAG in serum and the free beta-NAG in liver, spleen and kidneys increased. Latent beta-NAG levels decreased in all three organs the effect being dose related. Following A1 loading no elevation in total enzyme activity was observed, with one exception. Depending on A1 doses the spleen of the non-operated animals, the liver of both groups of animals and the serum showed a decrease in beta-Gluc activity. No effect on beta-Gluc activity was observed in the spleen of 5/6 NX animals or in the kidneys of either group of animals. The results confirm that high doses of Al induce toxic effects and damage the lysosomes in the liver, the spleen and the kidneys. The results indicate that the extent of lysosomal damage correlates with dose and duration of Al loading. Repeated administration of Al also interferes selectively with enzyme synthesis.

Acetylglucosamine↗
PubMed1987

Detection of IgG bound at the erythrocyte membrane by means of an immunohistochemical gold-silver technique.

The binding of IgG at the erythrocyte membrane during aging plays an important role in the elimination process of the cells by the reticulohistiocytic system. By means of an indirect protein A gold- and protein A gold-silver-method bound IgG was detected immunocytochemically on physiologically aged, pronase and neuraminidase treated red blood cells (RBC). At the light and electron microscopic level an increased binding of IgG at "old" as well as enzymatic treated cells in comparison to "young" and normal RBC was noted. The silver enhancement of gold particles visualized the immunostaining and permitted the semiquantitative analysis of the RBC by a scanning microdensitometer.

Erythrocyte Aging↗
PubMed1987

Morphometrical studies of erythrophagocytosis in the spleen.

The elimination of altered RBC was investigated morphometrically in the rat spleen by determination of the percentage of erythrophagosomes in macrophages. PHZ and diamide treated RBC led to a time dependent increase of the percentage of erythrophagosomes in comparison to normal spleens. The deformability of the target RBC was lowered as revealed by measurements with glass micropipettes. RBC-microvesicles and diamide treated RBC are primarily loaded with IgG and undergo a rapid elimination. PHZ-RBC and cells with a prolonged stay in the spleen are sequestrated by secondary mechanisms. Details of primary and secondary elimination are discussed.

Animals↗
PubMed1987

Membrane skeleton alteration--a factor promoting IgG receptor expression in the erythrocyte membrane.

IgG receptor expression after selective cross-linking of spectrin by means of diamide was investigated. A diamide concentration dependent IgG loading of erythrocytes was observed. Furthermore, diamide causes disturbance of lipid asymmetry, decrease of the anisotropy after topooptical staining of the glycocalyx, increase of the phagocytosis index and aggregation of the IMP's. Our findings support the hypothesis that the arrangement of the membrane skeleton at the inner aspect of the membrane is decisive not only for the lipid asymmetry but also for the spatial structure of the glycocalyx at the outer aspect of the membrane and thus for the degree of exposure and arrangement of IgG-receptors, which are thought to be localized at an extracellular portion of band 3 protein.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1987

Red blood cell aging--membrane skeleton alteration and IgG receptor expression.

Investigations were performed on aging of erythrocytes. It has been assumed that structural changes of the membrane result after exposer of the cells to certain environmental influences in vivo or in vitro. Cell aging can be connected with varying combinations of membrane structure disturbances. It is postulated that the messenger which signals membrane structure lesion is involved in a mechanism given by the expression of immunoglobulin G (IgG) receptor sites which bind autologous IgG1 and IgG3. This antibodies are cytophilic for macrophages. The performed studies demonstrated that an intact molecular arrangement of the membrane skeleton is not only a supposition for stabilization of the membrane asymmetry but also for IgG receptor masking to prevent an early elimination of the red blood cells from the organism.

Erythrocyte Aging↗
PubMed1986

The rate of lateral diffusion of phospholipids in erythrocyte microvesicles.

31P-NMR spectra of phospholipids in membranes of erythrocyte microvesicles isolated from outdated blood units were recorded in the temperature range 5 to 55 degrees C. Within that range the lineshape is strongly influenced by an increasing rate of lateral diffusion of phospholipids. At 36 degrees C a diffusion constant, D, of (2 +/- 1) X 10(-12) m2/s was obtained. The diffusion rate is by a factor of 3 to 10 greater than in erythrocyte membranes measured by the photobleaching technique and is comparable with values obtained for several lipid model membranes. The differences in lateral diffusion rates are probably connected with the depletion of microvesicle membranes in membrane proteins.

Blood Viscosity↗