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Biomedical subjects

A Weber

Publications and source records attributed to A Weber.

At least 343 records · Page 19Linked to original sources
PubMed1991

ADP-induced second wave aggregation in platelet rich plasma from hypercholesterolemic rabbits.

Platelet aggregation, ATP secretion and thromboxane formation were measured in platelet-rich plasma (PRP) of rabbits fed a cholesterol-rich (1%) diet for 3 months. Addition of ADP (0.6-2 microM) resulted in a clear biphasic aggregation in 7/8 cholesterol-fed rabbits. This was not seen in any of the 9 control animals kept on a standard diet for the same period of time (P less than 0.01). The secondary ADP-induced aggregation was irreversible and was accompanied by enhanced ATP secretion and significant thromboxane generation. There was no ADP-induced thromboxane formation and only a minor ATP secretion at the highest ADP concentration studied (20 microM) in control rabbits. These data confirm platelet hyperreactivity in hypercholesterolemia and demonstrate for the first time the occurrence of an ADP-induced second wave aggregation and granule secretion in citrated PRP of rabbits which may be triggered by thromboxane generation.

Adenosine Diphosphate↗
PubMed1991

[The occurrence of Cryptococcus neoformans in fecal samples from birds kept in human living areas].

With help of Guizotia creatinine agar (syn. bird seed agar) Cryptococcus (Cr.) neoformans var. neoformans was isolated from 71 (7.7%) of 925 investigated droppings of birds kept within human living area. Cr. neoformans was detected in droppings of 1.2% from 164 psittacines, in droppings of 1.7% from 118 budgerigars and in droppings of 18.4% from (carrier) pigeons. This yeast was not isolated from droppings of 13 small parrots, 10 eclectus parrots, 13 rosellas, 21 cockatiels, 6 Polytelidus sp., 32 Cacatua sp., 13 Carduelis sp., 5 waxbills, 5 starlings, 120 chicken, 9 turkeys, 2 geese, 2 Turdus sp., 1 duck and 1 gull.

Animals↗
PubMed1991

A monoclonal antibody sandwich immunoassay for serum amyloid A (SAA) protein.

An antibody sandwich immunoassay using two purified rat monoclonal antibodies to human serum amyloid A was developed and used to measure serum amyloid A in human serum. The assay was specific, sensitive, reproducible, and reliable and does not require denaturation of the specimen prior to assay. Serum amyloid A purified by hydrophobic interaction chromatography of acute phase human serum afforded a reliable standard for the assay. A significant (r = 0.69) correlation for SAA and C reactive protein values was found for 180 patient samples analyzed.

Antibodies, Monoclonal↗
PubMed1991

[Incidence of antibodies to Borrelia burgdorferi in dogs in small animal practice in North Bavaria].

With help of indirect immunofluorescent assay antibodies were detected to Borrelia burgdorferi, agent of Lyme borreliosis in 46 (35.5%) serum samples of 130 randomly selected dogs of a small animal practice in Northern Bavaria. A positive reaction of the indirect immunofluorescent assay was demonstrated in 15 cases in a serum dilution of 1:64, in 9 cases in a serum dilution of 1:128, in 5 cases in a serum dilution of 1:256, in 2 cases in a serum dilution of 1:512, in 3 cases in a serum dilution of 1:1024, in 2 cases in a serum dilution of 1:2048 and in 10 cases in a serum dilution of 1:4096 and higher. There was significant correlation between the symptoms pain of segments or muscles in dorsal region, between painful arthritis, between paralysis of hind legs or between chronic erythema ("hot spot") and the positive reaction of the immunofluorescent assay in the serum dilution of 1:256 ("borderline titre") and higher.

Animals↗
PubMed1991

Role of the N- and C-terminal actin-binding domains of gelsolin in barbed filament end capping.

Gelsolin is a bivalent Ca(2+)-modulated actin-binding protein that severs, nucleates, and caps filaments. In order to gain a better understanding of the capping mechanism we have studied N- and C-terminal gelsolin fragments, 14NT and 41CT, each of which contains a single functional actin-binding site. The very tight binding measured between gelsolin and the barbed filament end requires gelsolin to greatly decrease the dissociation rate constant of the terminal actin from this end. A mechanism that could account for the observed decrease in dissociation is one in which gelsolin links two actin monomers so that they dissociate more slowly as a dimer. This cannot be the only mechanism, however, since, as shown here, 14NT and 41CT, fragments with single actin-binding sites, decrease the dissociation rate of the capped terminal actin molecule. The observations suggest that these fragments induce a conformational change in the actin monomer that either increases the affinity or alters the kinetics of the terminal actin-actin bond. The available data argue for strengthening of the terminal actin-actin bond.

Acrosome↗
PubMed1991

[Detection of Salmonella-containing food using the 1-2 test].

133 samples of food were investigated for comparison of a recent commercially available 1-2 test (Biocontrol) with a cultural standard method (non-selective pre-enrichment in buffered peptone water, selective enrichment in Rappaport-Vassiliadis-medium and selenite brilliant-green mannitol enrichment broth, inoculation on two selective agars) for presence of Salmonella. The 1-2 test showed in positive results an accuracy ("sensitivity") of 94.7% and in negative results an assurance ("specificity") of 97.9% and is therefore considered suitable for detection of Salmonella contaminated food.

Culture Media↗
PubMed1991

Expression of the rat aldolase B gene: a liver-specific proximal promoter and an intronic activator.

The nature and location of the cis-acting DNA sequences regulating expression of the rat aldolase B gene has been investigated. Two liver-specific DNAse I hypersensitive sites were detected, one located just upstream from the cap site, the second in the middle of the first, 4.8-kbp-long, intron. A fragment of 190 bp 5' to the cap site behaved as a tissue-specific but weak core promoter: it directed a detectable reporter gene expression in the Hep G2 cells and hepatocytes, but not in fibroblasts. The tissue-specific expression was stimulated at least 16 fold when constructs contained the entire first intron. The intronic activating sequences could be ascribed to an inner 2 kbp fragment in which the downstream liver-specific DNAse I hypersensitive site was located.

Chloramphenicol O-Acetyltransferase↗
PubMed1991

Infectious complications of pediatric liver transplantation.

Twenty-five pediatric orthotopic liver transplantations (OLTs) performed in 22 patients at Sainte-Justine Hospital were reviewed for infections complications. One patient died within 12 hours posttransplantation and is excluded. The patients had an average age of 6.1 years (range, 1.25 to 19 years) and an average weight of 20.4 kg (range, 11 to 55 kg). Two patients (9%) were cytomegalovirus (CMV) seropositive and 9 of 19 patients (48%) were Epstein-Barr virus (EBV) seropositive preoperatively. Five of the donors (20%) were CMV seropositive. The most common indications for OLT were biliary atresia (8) and tyrosinemia (7). There were 4 deaths, for an overall mortality rate of 19%. In 3 patients, deaths were related to infection (CMV hepatitis and duodenitis with aortoduodenal fistula, adult respiratory distress syndrome [ARDS] with Streptococcus viridans pneumonia, Escherichia coli cholangitis with progressive hepatic failure). Fifteen patients (72%) had 41 major infections, most of them bacterial, during the first month posttransplantation. These include pneumonia (25%), line sepsis (17%), cholangitis (14%), and tracheitis (14%). There was only one major viral infection, a CMV hepatitis that occurred in the first month posttransplantation. Three patients had fungal infections (8%) associated with hepatic artery thrombosis and recurrent cholangitis. All three patients required retransplantation. There was only one protozoal infection (Pneumocystis carinii pneumonia) causing life-threatening respiratory failure, from which patient recovered without sequelae. Infection still remains a serious complication of OLT. Bacterial infection is common and is usually associated with technical complications. The low rate of CMV infection is related to low incidence of CMV in the donor pool and the minimal use of strong immunosuppressants.

Adolescent↗
PubMed1991

Primary intra-osseous carcinoma of the maxilla in a horse.

An 8-year-old Hannoverian horse developed a swelling of the maxilla caused by a tumour of the hard palate. On histological examination the tumour was diagnosed as a primary intra-osseous carcinoma of the maxilla, a rare odontogenic tumour not previously described in the horse.

Animals↗
PubMed1991

[Computerized tomography as routine examination procedure in the diagnosis of paranasal sinus diseases from the otorhinolaryngologist's viewpoint. Results].

The renaissance of endonasal microsurgery is not only based on a deeper knowledge of the mucociliar clearance and better operation instruments but depends as well as on the improved radiological diagnosis provided by computed tomography. Since 1986, high-resolution computed tomography in two plains has been part of the authors' preoperative routine diagnostic program for paranasal sinus diseases at their clinic. One hundred and fifty-eight computed tomograms of patients with chronic rhinosinusitis, complicated acute rhinosinusitis, and polyposis nasi were reexamined. The involvement of the paranasal sinuses and abnormalities of the lateral nasal wall were analyzed. The anterior ethmoid is the most frequently affected area in all of the diseases. The computed tomogram is most important for the rhinosurgeon. The ethmoid cell system can be visualized without superimposing structures. Therefore even circumscript pathologic mucosa alterations and the extent of the disease can be defined. All this enables the surgeon to put forward an exact diagnosis and to plan a safe operation as regards important physiological structures of the nose and paranasal sinuses.

Adolescent↗
PubMed1991

[Possibilities of treating nasal turbinates in the framework of endonasal microsurgery].

Pathologic alterations of the turbinates are common in infectious diseases of the nose and paranasal sinuses. Over 300 patients were treated for paranasal sinuses disease from 1986 to 1989 by endonasal microsurgery. One-third of the patients were found intraoperatively to have alterations of the middle and inferior turbinate causing obstruction and functional disorders of the nose and sinuses. Our concept comprises a step-by-step microsurgical approach to the turbinates. The technique and the results are presented.

Airway Obstruction↗
PubMed1991

Inability to express fimbriae results in impaired ability of Haemophilus influenzae b to colonize the nasopharynx.

We cloned into the structural fimbrial subunit gene from a fimbriated Haemophilus influenzae b a 1.5-kb kanamycin resistance gene. The resultant strain (RKAW5) was tested by Southern analysis, hemagglutination, and electron-micrographic examination to confirm gene inactivation. In comparison with the parent, RKAW5 exhibited a significant decrease in adherence to human buccal epithelial cells and in nasal colonization of yearling rhesus monkeys.

Animals↗
PubMed1991

[Occupational rehabilitation of gynecologic tumor patients. Occupational rehabilitation].

After primary treatment due to genital and breast cancer we judged with a total of three hundred and sixty three (363) working women the reintegration into their former jobs. The rate of rehabilitation amounted to 37.2 per cent. The temporary prescription of sheltered jobs--i.e. of work which corresponds with the needs of rehabilitation--was for 56.1 per cent of the women, whereas 23 per cent of the women had to take up a job other that before. In the first place the after-care covers general and gynaecological examination aiming at uncovering recurrence and second tumours and the earliest possible phase, and in the second place special attention is given to the therapy of hormonal deficiency, post treatment effects and incidental cases. The results which the team of specialists from many fields had got from group as well as individual talks are the basis for a follow-up care, mainly done by the psychologists. As a result of this a classification into some possible intervention groups. Special attention has to be given to women where there has been a family history with oncological diseases. A thoroughly coordinated and well-balanced approach to the gynaecological tumour--after-care is indispensable, i.e. it has to integrate firmly the occupational rehabilitation and to bear in mind never to ask too much of the patient.

Adolescent↗
PubMed1991

Occurrence of mycobacteria in drinking water samples.

33 ground water samples from three drinking water treatment plants and 72 samples from domestic drinking water distribution systems were studied for the occurrence of mycobacteria. 86 out of these samples tested positive for mycobacteria with concentrations generally ranging between 10(2) and 10(3) cfu/l. In one distribution system up to 4.5 x 10(5) cfu/l were found. Species identified by biochemical reactions and by thin layer chromatography of mycolic acids included: Mycobacterium gordonae (most water samples), M. flavescens, M. kansasii, M. chelonae (domestic water systems) and M. fortuitum (drinking water treatment plant). Most isolates did not show patterns of biochemical reactivity attributable to any known mycobacterial species.

Chromatography, Thin Layer↗