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Biomedical subjects

J Weber

Publications and source records attributed to J Weber.

At least 451 records · Page 25Linked to original sources
PubMed1990

The topographical relationship between optic disc and visual field in glaucoma.

The spatial relationship between anatomy and function in glaucoma was studied in 15 selected cases of focal damage. Based on planimetric data of the optic disc the anatomical site of damage was defined as the sector with the thinnest neuroretinal rim. Perimetric data were evaluated with regard to 21 regions of the 'Perimetric Nerve Fibre Bundle Map' (Weber & Ulrich 1990a). The site of damage was defined as those regions with at least 50% of depressed points. The site of the affected rim and the number of the corresponding Perimetric Nerve Fiber Bundles showed a linear correlation over a limited range of the superior and inferior pole of the disc. A 'functional disc map' could be established for 6 perimetric regions.

Glaucoma↗
PubMed1990

No evidence for genetic linkage of Gilles de la Tourette syndrome on chromosomes 7 and 18.

Gilles de la Tourette syndrome is a heritable neuropsychiatric disorder. In order to determine the chromosomal localisation of the locus involved, genetic linkage studies were initiated in six extended families. The Gilles de la Tourette gene has been tentatively assigned to chromosome 18q22.1. In our present study no evidence for genetic linkage on chromosome 18 and chromosome 7 was obtained. Data from the markers tested made it possible to exclude the whole of chromosome 18 and the chromosome 7q21.3-qter region as a site for the Gilles de la Tourette gene.

Chromosome Mapping↗
PubMed1990

Gummatous lesions in men infected with human immunodeficiency virus and syphilis.

Two HIV-infected men are reported who developed gummatous lesions more than 12 months after appropriate treatment of presumptive syphilis. In one patient the lesions developed without any change in the VDRL titre. The most likely explanation for these lesions is reactivation of syphilis in the context of HIV infection. As these lesions respond to penicillin, the possible reactivation of appropriately treated syphilis, or even yaws, should now be considered in any ulcerative lesion in HIV infected individuals at risk from treponemal infection.

Adult↗
PubMed1990

Uremic pruritus in patients on hemodialysis or continuous ambulatory peritoneal dialysis (CAPD). The role of plasma histamine and skin mast cells.

Fifty-four uremic patients (26 patients were maintained on continuous ambulatory peritoneal dialysis [CAPD] and 28 on hemodialysis [HD]) were screened for pruritus and plasma histamine. 50% of the patients on CAPD and 64.3% of patients on HD complained of current itching. The extent of itch, assessed by a score, was not significantly different between HD and CAPD patients. Plasma histamine levels showed no significant difference between CAPD and HD patients and no correlation between plasma histamine level and the extent of pruritus could be demonstrated. In six patients on CAPD and 9 patients on HD plasma histamine levels were determined before and three months after initiation of dialysis treatment; no substantial change could be observed. In some patients skin biopsies were obtained from the gluteal region in order to determine the number of skin mast cells. The number of mast cells did not show a significant difference between controls (n = 12), uremic patients before initiation of dialysis treatment (n = 8), patients on CAPD (n = 11) and patients on HD (n = 13). There was no relationship between the level of plasma histamine, the number of skin mast cells and the extent of pruritus in uremic patients.

Adult↗
PubMed1990

[Use of graphic analysis of topographic trends in perimetry].

A new graphical procedure for topographical trend analysis (graphical analysis of topographical trends: GATT) is able to distinguish several possibilities of evolution of a visual field. Analysis of 100 cases with GATT made it possible to classified them into 10 types of development. This signifies an improvement over global statistical analysis, which distinguishes only 3 different types of evolution. In addition, the individual evaluation of visual field development with GATT is enhanced by quantitative and topographical differentiation within an evolutional type.

Computer Graphics↗
PubMed1990

[Atypical lung cancer resection? A clinical observation pro and contra].

The answer to the title of atypical resections of lung cancer is controvers. The experiences about a long time shows there is'nt a difference between the 5-year-survival-rate after lobectomy and pneumonectomy in the same stages. From 1970-1986 we carried out 195 atypical resections of lung cancer. The postoperative stage pT1-2N0M0 was constituted in 149 patients. The 5-year-survival-rate of this patients is'nt different to the results after lobectomy. Such resections are a very good method in the surgery of lung cancer and for the rehabilitation of such patients.

Adult↗
PubMed1990

A hemangioendothelioma-derived cell line: its use as a model for the study of endothelial cell biology.

The purpose of our research was to develop a stable murine cell line that could serve as a general model for the study of microvascular endothelial cells. To do so we have characterized an endothelial cell line originally derived from a mouse hemangioendothelioma. Endothelioma cells synthesize angiotensin-converting enzyme, express surface receptors for acetylated low density lipoprotein, produce thrombospondin and show intracellular staining with an antibody to von Willebrand antigen. The response of endothelioma cells to endothelial cell mitogens, known angiogenesis-inducing factors, extracellular matrix substrate (Matrigel), and various cytokines was measured. Endothelioma cells show an increased proliferative response to extracts from hypothalamus but only marginally to recombinant fibroblast growth factor or purified endothelial cell growth factor. Rearrangement of cells forming tube-like connections were induced by Matrigel. The chemokinetic responses generally correlated with angiogenesis-inducing properties of the test substances. The results support the conclusion that the endothelioma cell line maintains characteristic endothelial cell properties and behaves in vitro in a manner similar to microvascular endothelial cells.

Animals↗
PubMed1990

[Bipolar impulses or direct current as an adjuvant treatment of incisional hernia? Comparative experimental animal study].

The electrostimulation of the cicatricial healing in the abdominal wall were tested in 119 Wistar rats by means of bipolar rectangularly pulsed current (0.87 Hz, +/- 25 mu A) and direct current (1 mu A). Doubling of the fascia of an abdominal wall hernia was carried out in three groups of rats. In the first group the operational region was stimulated by rectangularly pulsed current, strong proliferated cicatrices were formed with premature production of fibroblasts and collagenous fibres, fast maturation, and high strength. In the second group it was stimulated by direct current, a less exact longitudinal orientation of the collagenous fibres and a slower cicatricial maturation were shown. The third group applied as a control showed a cicatricial distension up to 5 mm. The electrostimulation of the proliferation of connective tissue and cicatricial healing could be pointed out between different tissues (peritoneum and fascia).

Animals↗
PubMed1990

[A new strategy for automated static perimetry].

The threshold of sensation in perimetry is a range where the probability of perception varies between 0% and 100%. The size of the range is dependent on sensitivity: it increases towards lower sensitivities. A new measurement strategy is presented where the luminance steps between the presentations vary according to the actual luminance level. Luminance steps and threshold variation are always kept in a constant relation. Thus, efficiency of perimetric measurements shall be improved. Already a single crossing of the threshold with dynamic steps gives reproducible results. In one field with 54 points, the mean standard deviation of 3 repeated measurements was 19% greater than that of a conventional 4dB-2dB-double-crossing strategy, but the test time was 56% less.

Adult↗
PubMed1990

[Constipation symptoms studied by a standard questionnaire and anorectal manometry before and after promontory rectopexy (Orr-Loygue technic) in 25 female patients].

Intractable constipation is frequently observed after rectopexy. The aim of our study was to look for clinical and manometric data, which could help to predict postoperative constipation. Twenty-five consecutive female patients treated by Orr-Loygue rectopexy were asked to answer a standard questionnaire and underwent anorectal manometry pre- and postoperatively. Nineteen patients complained of constipation after surgery. Preoperative constipation was significantly more frequent in patients who complained of postoperative constipation, than in patients who did not. Preoperative colonic transit time study in 8 patients was not useful in predicting postoperative constipation. Moreover, symptoms of constipation were quite similar pre- and postoperatively in the 19 patients complaining of postoperative constipation. Anorectal manometric data were not different between patients who complained of postoperative constipation and patients who did not. Therefore preoperative complaints of constipation are most important to consider before rectopexy.

Adult↗
PubMed1990

[Borderline lesions of the breast: clinical and radiological study of 20 cases].

We describe the clinical and mammographic signs observed in 20 patients with atypical hyperplasia of the breast. The clinical signs include abnormalities noted at palpation (tumefaction, masses, clusters of nodules) and nipple discharge. The mammographic signs include rounded, clearly delineated opacities with benign appearances, or spiculated masses possibly associated with microcalcifications, stellate opacities, and isolated foci of microcalcifications. Galactography may visualize milk ducts dilatation. Both the clinical and mammographic signs are non-specific and even equivocal and do not allow pre-operative diagnosis of non-specific lesions.

Adult↗
PubMed1989

Expression of class I histocompatibility antigens in neuroectodermal tumors is independent of the expression of a transfected neuroblastoma myc gene.

We have evaluated the relationship between the neuronal myc gene (NMYC) and class I major histocompatibility complex (MHC) expression in human neuroblastoma (NB) tumor cell lines. Class I MHC surface Ag expression in NB cell lines varied from nearly undetectable to levels nearly as high as in a lymphoblastoid cell line. Class I MHC mRNA levels in NMYC-amplified NB cell lines were lower than levels observed in single copy NMYC NB cell lines. However, considerable variation in class I MHC surface Ag and mRNA expression was evident in NMYC-amplified cell lines. To determine directly whether NMYC might modulate class I MHC expression in NB, we transfected a plasmid containing a recombinant NMYC gene into two tumor cell lines derived from a NB and a related neuroepithelioma tumor. Constitutive overexpression of the recombinant NMYC gene produced no consistent change in class I MHC surface Ag or mRNA levels. To determine whether class I MHC expression might be developmentally regulated in adrenal medullary cells, the precursor cells of adrenal NB tumors, beta 2-microglobulin expression was measured in fetal and adult adrenal glands. beta 2-Microglobulin expression was not evident in the neuroblasts of a 24-wk-old fetal adrenal gland, whereas beta 2-microglobulin expression was present in the adult adrenal medulla. These data suggest that variation in class I MHC expression among NB cells may reflect the developmental stage at which neuroblasts were arrested during tumorigenesis.

Adrenal Glands↗
PubMed1989

[Transpapillary cholangioscopy. A new diagnostic and therapeutic dimension].

Transpapillary cholangioscopy (TCS) was performed in 52 patients (12 men, 40 women; mean age 61.6 [39-86] years) in whom endoscopic retrograde cholangiography had not provided a firm diagnosis. TCS was unsuccessful in five patients for technical or anatomical reasons. In 33 of the remaining 47 patients (70%) the procedure gave diagnostically or therapeutically useful results: In seven patients with tumour in the biliary tract biopsies were obtained, while in eight with extraductal stenoses cholangiography was made possible and provided the diagnosis. In eight patients residual gall stones were removed; in three cholangioscopically guided lithotripsy was successful. TCS proved to be a simple method with few complications; it significantly improved the diagnosis and treatment of diseases in the biliary tract.

Adult↗
PubMed1989

[Endoscopic perfusion manometry: diagnosis of functional biliary disorders].

During the last years the endoscopic perfusion manometry developed many new recognitions about the courses of pressure and motility at the sphincter Oddi. The clinical and experimental application of the method concentrated itself to the proof of functional disturbances. Many results are contradictory and a whole series of questions is unsolved. The own investigations concentrated themselves on pressure measurements in the common bile duct in patients with removed gallbladder, in whom by comprehensive diagnostic measures no organic disease of the biliary tract could be found. Two groups of patients were compared. Patients of group 1 (n = 14) had no biliary symptoms after cholecystectomy. The patients of the second group (n = 20) continued to have biliary complaints after cholecystectomy, or they again occurred after symptom-free interval. At the beginning of the investigation the pressure in the common bile duct was the same in the two groups. In group 1 the pressure remained constant also during the manometry and the patients remained without any complaints. However, in group 2 a gradual increase of pressure and biliary complaints developed during manometry. These occurred after an average pressure increase of 8 Torr. The velocity of the increase of pressure well correlated with the intensity of the complaints. The symptoms during manometry were identical with those cited in the anamnesis. The pressure increase in the common bile duct is regarded as an expression of a functional disturbance of the sphincter of Oddi. The constant perfusion rate (1.3 ml/min) in this group of patients is sufficient as volume load, in order to detect a disturbed drainage capacity of the papilla. On its part the increase of the pressure is responsible for the evocation of the complaints.

Ampulla of Vater↗
PubMed1989

Nematocysts (stinging capsules of Cnidaria) as Donnan-potential-dominated osmotic systems.

Isolated nematocysts (capsules of stinging cells in Cnidaria) from the freshwater polyp Hydra vulgaris [Weber, J., Klug, M. & Tardent, P. (1987) Comp. Biochem. Physiol. 88B, 855-862] are under a constant internal osmotic pressure of 12.5 MPa. The capsular wall which withstands this considerable pressure has an average elasticity modulus of approximately 1 GPa, enabling the cyst to swell from its relaxed state to more than double its volume. If the large concentrations of Mg2+ and Ca2+ within isolated nematocysts are substituted by alkali ions, the capsular volume increases by 15% and the final osmotic pressure rises to 15.3 MPa whereas after substitution by Ca2+ a decrease to 90% of the volume and 6.5 MPa is observed. Evidence obtained from the osmotic behavior of nematocysts, as well as data from in vitro exchange of their cations, are consistent with a physicochemical model in which the internal osmotic pressure of nematocysts and thus their ability to discharge is governed by the cationic composition of the content and the salt concentrations in the environment.

Animals↗