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Biomedical subjects

G Wegner

Publications and source records attributed to G Wegner.

At least 55 records · Page 3Linked to original sources

[Deformability of stored erythrocytes as a criteria for their in vivo survival rate].

The loss of deformability observed in erythrocytes stored as whole blood for 36 days (ACD-AG) or as buffy-coat free erythrocyte concentrate (EK) was characterized by measuring their filterability. During the first 3 weeks the index of filterability for ACD-AG erythrocytes increased only slightly and rose to about 140% of its initial value on the 36th day. In contrast, a heavy loss of deformability (increase of the filterability index to more than 600%) was detected for erythrocytes from EK, which, from a rheological point of view, is apt to raise doubts of using this stored blood. An incubation of 1 hour at 37 degrees C in fresh plasma did not result in improving the deformability. A cell volume loss of more than 20% connected with an increase of the inner viscosity to more than 400% was found to be the cause of this decrease of deformability. These rheological differences are also reflected in the 24 hours in vivo survival rate (SR), if the "early loss" of damaged erythrocytes immediately after transfusion is taken into account. Whereas the SR values of 80% for whole blood erythrocytes do not change significantly, the SR values for EK values can be found to reach 54% approximately.

Blood Transfusion↗

Comparison between continuous and intermittent administration of Estracyt in the treatment of carcinoma of the prostate.

Ninety-five patients with prostatic carcinoma, stages A-D and of all histological grades were randomized between a continuous and an intermittent treatment regimen of Estracyt (estramustine phosphate). 77 patients were evaluated (46 with continuous and 31 with intermittent therapy). Remissions were seen in 13 (28%) and (13%), respectively. Stable disease was recorded in 30 (65%) and 24 (77%), respectively. Progression experienced 3 (6%) and 3 (10%) respectively. 19% were unable to continue therapy due to intolerable gastrointestinal side effects (7 patients receiving continuous and 8 patients receiving intermittent therapy).

Aged↗

Distribution of albumin in normal and regenerating livers of mice. A light microscopic immunohistochemical and autoradiographic study.

The conditions affecting the immunohistochemical identification of albumin in livers of male NMRI-mice were investigated by light microscopy. In normal livers albumin is randomly distributed, revealing a pancytoplasmic nearly homogen reaction in groups of hepatocytes or single parenchymal cells. However, combined autoradiographic studies after pulse labelling with 3H-valine and perfusion experiments with human albumin indicate that this distribution is caused by albumin from blood plasma and does not reflect true protein synthesis. After perfusion of the livers followed by immunohistochemical amplification techniques which allowed to dilute the primary antibody up to 1:30,000, albumin could be detected nearly in all liver parenchymal cells as granular deposits decreasing in its density from periportal fields towards the terminal hepatic venules. In regenerating livers due to partial hepatectomy no remarkable differences in granular albumin deposits between G1- and S-phase of the cell cycle could be detected as was demonstrated by combined immunohistochemistry and 3H-dThd-autoradiography. However, during mitosis the content of albumin was often considerably reduced.

Albumins↗

[Immunohistochemistry: theoretical potentials and practical application].

Immunhistochemical methods are increasingly used and their application in surgical pathology is obvious. Nine different immunohistochemical techniques are compared in this review article. The peroxidase anti-peroxidase method of Sternberger et al. (1970), the avidin biotin complex method of Hsu et al. (1981) and the labeled avidin biotin technique of Guesdon et al. (1979) are to be preferred. Two step methods using labeled antibodies such as alkaline phosphatase or peroxidase-labeled second antibodies are less sensitive. However, two-step methods using alkaline phosphatase-labeled antibodies offer the advantage of double staining procedures since alkaline phosphatase reacts with different azo dyes and results in a wide spectrum of colours in the final reaction product. At present, the major problems of immunohistochemistry in daily work are the selection of the fixative and of appropriate controls. Though both problems remain unresolved, immunohistochemical methods should be used for special problems in surgical pathology.

Alkaline Phosphatase↗

Investigations on the deformability of human red blood cells stored in different preservative solutions.

Deformability changes of red blood cells stored either as whole blood or as different resuspensions in sucrose-free or sucrose-containing media were characterized by measuring red cell filterability during 36 days of storage. For whole blood and SAG-resuspensions only a slight increase of the filterability index was observed during the first 3 weeks; after 36 days it was elevated 1.4-fold (whole blood) and 1.8-fold (SAG-resuspension). In contrast, a strong deformability loss (increase of the filterability index to more than the 6-fold) was observed for red blood cells stored in sucrose-containing CDS-AG medium. This deformability loss is caused by an increase of the internal viscosity (at least 4-fold) due to the shrinkage of red blood cells by more than 20%. After incubation for 1 h in fresh plasma no changes of filterability could be found. The in vivo behavior of such rigid cells is discussed with regard to references about the posttransfusion survival.

Blood Preservation↗

Analysis of mast cells in rheumatoid arthritis and osteoarthritis by an avidin-peroxidase staining.

As demonstrated by labeling with peroxidase, avidin was found to bind selectively and distinctly to mast cell granules. Inhibition studies suggested that avidin is bound by heparin. Based on this new mast cell staining procedure, mast cell distribution in the inflamed synovium of rheumatoid arthritis (RA) and osteoarthritis (OA) has been investigated. In the subsynovial layer, a significant decrease in mast cell numbers was observed in RA-synovium when compared with OA-synovium. This decrease correlated with the presence of lining cell ulcers and granulation tissue and can be interpreted as the result of mast cell degranuation induced by complement-mediated or immune complex-triggered mechanisms.

Arthritis, Rheumatoid↗

Investigations concerning the correlation between liver cell proliferation, production of alpha-fetoprotein, and DNA-synthesis of lymphocytes in the spleen of NMRI-mice. An autoradiographic and immunohistochemical study.

To obtain more information concerning the correlation between liver cell proliferation, production of alpha-Fetoprotein (AFP) and DNA-synthesis of lymphocytes in the central and peripheral parts of periarteriolar lymphatic sheaths ( PALS ) of the spleen, these parameters were monitored in intervals of 12h after CCl4-poisoning of NMRI-mice using autoradiographic and immunohistochemical methods. The results indicate that synthesis of AFP is not linked closely to proliferation of hepatocytes because in contrast to DNA-synthesis the production of AFP was only detectable in a very small subpopulation of liver parenchymal cells reaching a peak before the majority of hepatocytes was found to enter the S-phase of the cell cycle. Beyond this, in vivo no general suppressive effect of AFP on proliferation of lymphocytes in preferably T-dependent areas of the spleen could be detected since the 3H-TdR-labeling index in these compartments increased, reaching a peak 48h after the maximum of hepatocytes producing AFP had occurred.

Animals↗

Immunoglobulin G binding to human erythrocytes.

The binding of 125iodine labelled human IgG to allogenic erythrocytes was studied at various ratios of free IgG per cell. At low concentrations of free IgG a high affinity binding was measured, which is with respect to its apparent association constant (2.8 x 10(13) mol-1) most likely a specific receptor binding and might indicate aged cells of those destined for elimination. At higher concentrations of free IgG the erythrocytes were coated by IgG in a non-saturable manner as reported by Grob et al. (Immunology 13, 189 (1967)). The erythrocyte-bound labelled IgG, which remained in the range from 15 to 400 molecules IgG per cell after intensive washings could not be chased by unlabelled IgG. This cell-bound IgG (high affinity binding) was increased 7-fold after complete ATP-depletion of erythrocytes and was 4 times higher after erythrocyte storage for 42 days. It appears that it is not the number of bound IgG molecules alone which is important for erythrocyte recognition by macrophages but also the arrangement of IgG molecules bound to membrane polypeptides.

Adenosine Triphosphate↗

[One-time therapy of acute cystitis in women. Comparison between gentamycin and amoxicillin].

In a randomized trial 65 women with symptoms of acute cystitis and significant bacteruria were treated with 120 mg gentamycin intramuscularly or 3 g amoxicillin orally. The patients were selected by excluding those with recurrent infection and involvement of the upper urinary tract (by history and clinical examination). The urine was sterile in 53 patients (82%) after a one-week treatment-free interval. The results indicate that there was no statistically significant difference between the two treatment groups. Further diagnostic tests revealed an underlying urological disease in five of the 12 remaining patients.

Acute Disease↗

[Optimizing conservative urinary calculus expulsion].

A multicentric randomised and prospective study on conservative treatment of ureteric calculi had been performed. The frequency and transit time of spontaneously passing of the stones, side effects and cost of treatment have been compared under classic spasmoanalgetic therapy and a phytotherapeutic medicament (Urol). In the group with spasmoanalgetic therapy 85.5% of the stones passed spontaneously, in the group with Urol medication 89.3% of the stones. There was no significant difference concerning the transit time of stones between the two groups, but side effects and costs were less in the Urol-group.

Adolescent↗

On the action of prednisolone and ethane-1-hydroxy-1,1-diphosphonate (EHDP) on rabbit bone.

Ethane-1-hydroxy-1,1-diphosphonate (EHDP) (0.1 mg and 1 mg P/kg) and prednisolone (3.7 mg/kg) were administered separately and in combination to young rabbits for a period of 100 days. The results of the experiment show that EHDP is able to reduce the loss of bone substance per unit volume caused by prednisolone. The histological changes in the epiphyseal cartilage noted after prednisolone are not influenced by diphosphonate. The marked formation of fat marrow demonstrable in the prednisolone group does not occur in the prednisolone-diphosphonate group.

Animals↗

Synthesis of alpha-fetoprotein (AFP) and cell proliferation in regenerating livers of NMRI mice after partial hepatectomy. An immunohistochemical and autoradiographic study with 3H-thymidine.

To get more information concerning the relation between cell proliferation and the synthesis of alpha-fetoprotein (AFP), liver regeneration and AFP production was followed simultaneously in short intervals in NMRI mice after two-thirds hepatectomy using autoradiographic and immunohistochemical methods. The results indicate that AFP synthesis is not linked closely to cell proliferation in the sense that each proliferating hepatocyte synthesizes AFP during a definite phase of the cell cycle. However, AFP production, as measured by the index of anti-AFP positive hepatocytes, occurs in a very small population of parenchymal cells when the bulk of the hepatocytes has just passed the S-phase and is considered to be in the G2-, M or early G1-phase of the cell cycle when the cells are still in an undifferentiate state.

Animals↗

[Mucous adenocarcinoma of the urinary bladder (urachal carcinoma) (author's transl)].

A report is presented of 5 cases of urachal carcinomas (3 women and 2 men). The mucous adenocarcinomas were located on the apex of the urinary bladder. In 3 cases partial cystectomy and in 2 cases a subtotal cystectomy were performed. Two patients were treated with cytostatics postoperatively. The prognosis of urachal carcinomas is poor. 3 patients had metastases to the bones, cerebrum and peritoneum. Diagnostic and therapeutic procedures are discussed.

Adenocarcinoma, Mucinous↗

Continuous versus intermittent oral therapy with estramustine phosphate (Estracyt).

A preliminary report is presented of prospective, randomized study with continuous and intermittent oral Estracyt treatment in patients with prostatic carcinoma. It seems that the therapeutic effect of intermittent treatment is as favorable as continuous therapy. Side effects and costs are lower with intermittent therapy.

Drug Administration Schedule↗