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Biomedical subjects

J Weber

Publications and source records attributed to J Weber.

At least 523 records · Page 29Linked to original sources
PubMed1988

[The combination of phlebography and invasive measurement of venous pressure].

Phlebographic visualisation offers the highest spatial resolution of all imaging methods both in respect of veins of the leg and pelvis and of the abdomen. Phlebography offers optimal conditions for assessing morphological changes at the veins and in their direct neighbourhood. No quantitative information is available via phlebography if haemodynamics are disturbed; qualitative information is yielded merely to a restricted extent (by assessing flow velocity and collaterals). Direct sanguinous measurement of venous blood pressure is particularly suitable for the quantitative and qualitative assessment of disturbed haemodynamic conditions; in this respect it stands out among the function tests based on the employment of apparatures. If it is combined with phlebography, it is possible not only to optimise the diagnostic yield in the hands of one investigator, but also to reduce the invasiveness of both methods to one single puncture, since the puncture needle is at the same time also an instrument to measure the pressure. The article points out the possibilities and limitations of combining a) ascending phlebography of the leg and pelvis with peripheral venous pressure measurement (phlebodynamometry) and b) visualisation of the veins of the pelvis and vena cava inferior with central sanguinous venous pressure measurement (CP). Indicatious and technical execution are described.

Adult↗
PubMed1988

[Endometriosis externa thoracalis].

The incidence of endometriosis is between eight and 15 percent among sexually mature women, with peaks being in the third and fourth decades of age. External thoracic endometriosis is associated with implantation of endometrial tissue into lung, pleura, bronchial system, and diaphragm. Major indicators symptoms of thoracal endometriosis include haemoptysis, thorax pain, recurrent spontaneous pneumothorax, and haemorrhagic pleural effusion, with all these manifestations being temporally coordinated with menstruation. Bronchoscopy and radiography are used for diagnosis, while surgery, hormonal treatment, and radiotherapy are used for therapeutic action. One patient with systemic endometriosis is reported in greater detail in this paper.

Adult↗
PubMed1988

[Colonic pseudo-obstruction associated with diffuse digestive and vesical motor anomalies. Apropos of 2 cases].

Two patients with acute colectasia, and acute urinary retention following pregnancy (case n. 1) and Klebsiellae septicemia (case n. 2) requiring endoscopic exsufflation in both cases, were seen. At onset, both patients had esophageal and anorectal manometric abnormalities with right colonic transit delay, and in case n. 2 urodynamic perturbation. Several months later, abnormalities disappeared in case 1, but remained unchanged in case 2. Jejunal manometry performed in case 2 showed decreased interdigestive complex frequency. These data suggest that: 1) acute colectasia may be major expression of digestive and urinary motility disorders, 2) acute colectasia can be the first symptom of a chronic disease, suggesting the usefulness of manometric studies in these patients, once the acute episode is over.

Adult↗
PubMed1988

Prevalence of ocular microorganisms in hospitalized and stabled horses.

Microorganisms from normal eyes of hospitalized and stabled horses were identified, and the frequency of isolation was compared between the 2 groups. Using standard techniques, swab specimens from both eyes of 22 hospitalized horses and both eyes of 18 stabled horses were cultured for aerobic bacteria and fungi. Ninety-six aerobic bacteria and 57 fungi were isolated. The predominant bacterial isolates were gram-positive organisms, most of which belonged to the genera Corynebacterium, Bacillus, Staphylococcus, and Streptomyces. Gram-negative organisms comprised less than one-fourth of the bacterial isolates, with the genera Neisseria, Moraxella, and Acinetobacter being the most commonly isolated. Environmental fungi Cladosporium and Alternaria accounted for half of all fungal isolates. In only 5 horses were fungi isolated without accompanying isolation of bacteria. The frequency of isolation of fungi was higher (P less than 0.01) in stabled horses. For bacteria, the frequency of isolation was higher (P less than 0.08) in male horses. Results of susceptibility testing were recorded as the percentage of all isolates susceptible to a given antimicrobic drug. Bacterial isolates were highly susceptible (greater than or equal to 90%) to neomycin, polymixin B, gentamicin, and chloramphenicol. Overall, filamentous fungi had highest susceptibility to natamycin (97%). Miconazole was highly efficacious (100% susceptibility) against Fusarium and Aspergillus.

Animals↗
PubMed1987

Critical carboxyl group(s) in Na+-dependent cotransporters of the intestinal brush-border membrane.

We have previously provided functional evidence for a role of carboxyl group(s) in the mechanism of coupling of Na+ and D-glucose fluxes by the small-intestinal cotransporter(s) (Kessler, M. and Semenza, G. (1983) J. Membrane Biol. 76, 27-56). We present here a study on the inactivation of the Na+-dependent transport systems, but not of the Na+-independent ones, in the small-intestinal brush-border membrane, by hydrophobic carbodiimides. Although marginal or insignificant protection by the substrates or by Na+ was observed, the parallelism between Na+-dependence and inactivation by these carbodiimides strongly indicates the role of carboxyl group(s) previously indicated. Contrary to the carboxyl group identified by Turner [1986) J. Biol. Chem. 261, 1041-1047) in the sugar binding site of the renal Na+/D-glucose cotransporter, the carboxyl group(s) studied here probably occur elsewhere in the cotransporter molecule.

Amino Acids↗
PubMed1987

Novel approaches towards characterization of the high-affinity nucleotide binding sites on mitochondrial F1-ATPase by the fluorescence probes 3'-O-(1-naphthoyl)adenosine di- and triphosphate.

The fluorescence properties of 3'-O-(1-naphthoyl)adenosine di- and triphosphates (termed N-ADP and N-ATP, respectively) were investigated in detail. Of special importance for the use of these analogues as environmental probes is their high quantum yield (0.58 in water) and the polarity dependence of shape and wavelength position of the emission spectrum. Upon binding of N-ADP and N-ATP to mitochondrial F1-ATPase, the fluorescence intensity is markedly decreased, due to polarity changes and 'ground-state' quenching. Using this signal for equilibrium binding studies, three (at least a priori) equivalent nucleotide-binding sites were detected on the enzyme. The perspective intrinsic dissociation constants are as follows: N-ADP/Mg2+ 120 nM; N-ATP/Mg2+ 160 nM; N-ADP/EDTA 560 nM; N-ATP/EDTA 3500 nM. For bound ligand the environment was found to be rather unipolar; the rotational mobility of the fluorophore is restricted, its accessibility for iodide anions (as a quencher) is hindered. These facts show a location of the binding sites quite deeply embedded in the protein. The conformation of the binding domains is strongly dependent on the absence or presence of Mg2+, as can be seen from the relative efficiencies of the singlet-singlet energy transfer from tyrosine residues in the protein to bound naphthoyl moieties. Investigation of the binding kinetics revealed this process as biphasic (in presence of Mg2+). After the first fast step (kon greater than 1 X 10(6) M-1 X s-1), in which the analogue is bound to the enzyme, a slow local conformational rearrangement occurs.

Adenosine Diphosphate↗
PubMed1987

Isolation of variants resistant to methylglyoxal bis(guanylhydrazone) from adenovirus-transformed rat cells.

It is presumed that proteins encoded by viral oncogenes interact with proteins encoded by cellular genes to bring about the transformed phenotype. To demonstrate the existence of such cellular genes we attempted to isolate mutants with a nontransformed phenotype from an adenovirus-transformed rat cell line (F4) which contains multiple copies of the transforming E1 region. F4 cells were mutagenized with ethyl methanesulfonate and variants resistant to the anticancer drug methylglyoxal bis(guanylhydrazone) were selected. The proportion of such variants was about one in 10(6) and increased 5-fold after mutagenesis. Two variant clones (G1 and G2) were isolated and characterized: they were 5-fold more resistant to methylglyoxal bis(guanylhydrazone); they had a stable phenotype; they showed decreased drug uptake; they had a reduced ability to grow in soft agar, low serum, and nude mice; there was no detectable change in the restriction pattern of integrated viral genes or in the expression of the E1a and E1b proteins. These properties suggest that selection for methylglyoxal bis(guanylhydrazone) resistance may result in the isolation of variants with phenotypic characteristics of nontransformed cells. It was likely that these variants were altered in a cellular function required for the maintenance of the transformed phenotype.

Adenoviridae↗
PubMed1987

[Colonic lipoma].

Explore the source record for details and available documents.

Adolescent↗
PubMed1987

Frequency of infections among rheumatoid arthritis patients, before and after disease onset.

The self-reported frequency of genitourinary and bronchopulmonary infections in postmenopausal women with rheumatoid arthritis (RA) and in postmenopausal women with osteoarthritis and/or soft tissue rheumatism was compared. Neither before, nor after the onset of joint disease was a higher frequency reported by the RA patients. The previously established increased mortality from infectious disease among RA patients might be due to a more severe infectious disease course, leading to an increased case-fatality rate.

Aged↗
PubMed1987

Human immunodeficiency virus (HIV) infection in the regular sexual partners of homosexual men with AIDS and persistent generalised lymphadenopathy.

Thirty-five homosexual men who had been the regular sexual partners (for at least 6 months) of anti-HIV-positive patients with AIDS (N = 18) or PGL (N = 17) were studied. Twenty-one (60%) were seropositive, but 14 (40%) were consistently anti-HIV-negative. The duration of relationship with the index case was not statistically different in seropositive compared to seronegative partners; median 26 months (range 7-60) vs 30 months (range 7-60). However, seropositive partners had a significantly higher monthly number of other sexual partners and sexually transmitted diseases and a higher frequency of insertive and receptive anal intercourse in the preceding five years. The risk of acquiring HIV infection was significantly increased by frequent receptive anal intercourse when the frequency of insertive was controlled for but not the converse. Seronegative partners had undetectable antibodies by live and fixed cell immunofluorescence and by radioimmunoprecipitation and were repeatedly negative by competitive enzyme immunoassay. Furthermore, the sera of seronegative partners lacked HIV neutralising activity. Peripheral blood mononuclear cells (PBMCs) from seronegative partners, stained with monoclonal antibodies to seven different CD4 epitopes, revealed no differences when compared to those from heterosexual controls and no qualitative differences from cells from seropositive individuals. In addition, PBMCs from seronegative partners could be productively infected by HIV in vitro. If resistance to infection in seronegative partners exists, then it is likely that mechanisms other than a specific humoral immunity or CD4 polymorphisms are involved.

AIDS-Related Complex↗
PubMed1987

Synchronization of stimulated urothelial proliferation. Experimental models for cell cycle specific testing of bladder carcinogens.

In the present experiments an attempt was made to synchronize urothelial proliferation in the urinary bladder of rats stimulated by either a partial cystectomy (one-third resection) or a single i.p. administration (100 mg/kg) of CP. To temporarily inhibit DNA synthesis HU was given intraperitoneally in multiple fractionated doses (0.1 mg/g each) at hourly intervals during the period of most pronounced proliferative activity between 33 and 55 h after partial cystectomy and between 26 and 44 h after injection of CP. Following partial cystectomy the 3H-TdR index rapidly increased after termination of the HU administration reaching peak values of 54% and 56% at 6 and 8 h, respectively. Thereafter, there was a sharp decline of the percentage of DNA synthesizing cells within 2 h to 24% at 10 h. Then 16 h after removal of the HU block the 3H-TdR index amounted to 15%. At 20 h the labeling increased again to 22%, indicating that the initially blocked cells were capable of going through another cell cycle. After 1 week the 3H-TdR index was 2.5% and after 15 days 0.2%. Synchronously with the decrease of DNA synthesis the mitotic index rapidly increased reaching a maximum value of 4.3% at 10 h. The total fraction of 3H-TdR-labeled cells (growth fraction) was 57%. Following administration of CP 3H-TdR incorporation increased steeply after the last injection of HU and at 6 h a maximum value of 50% was obtained. Subsequently, the 3H-TdR index gradually decreased to 11% after 12 h. At 8, 15, and 30 days labeling indices of 1.9%, 0.5%, and 0.3% were determined. The mitotic index was highest with 0.21-0.22% between 12 and 16 h after removal of the HU block. The growth fraction amounted to 53%. The results reported here show a satisfactory degree of synchrony of stimulated urothelial proliferation obtained by multiple fractionated doses of HU. In particular the cystectomy model will be useful for testing possible cell cycle specificity of urothelial carcinogenesis.

Animals↗
PubMed1987

Microdissection and microcloning of the long arm of human chromosome 7.

DNA-fragments from the region of the long arm of human chromosome 7 to which the CF-locus has been mapped recently were isolated by microdissection and microcloning. We developed a new fixation procedure resulting in inserts of 1.0-7.0 kb in length with a mean value of 2.9 kb. Regional mapping of three clones on 7q was carried out by the use of different hybrid cell lines containing fragments of human chromosome 7.

Animals↗