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Biomedical subjects

W Weiss

Publications and source records attributed to W Weiss.

At least 127 records · Page 7Linked to original sources
PubMed1988

Lobe of origin in the attribution of lung cancer to asbestos.

Lung cancer originates most commonly in the upper lobes in the general population but among workers with asbestosis it is most common in the lower lobes. Published data on lobar distribution were used to estimate the probabilities that lung cancer among asbestos workers is attributable to exposure to asbestos. This attribution varies directly with the relative risk. Critical values of the relative risk at which attribution of lung cancer to asbestos equalled its attribution to other causes, mainly smoking, were calculated. At a relative risk above 2.81 upper lobe cancers were more likely to be due to asbestos than not. For middle and lower lobe cancers, the critical relative risk was 1.55. These critical values were compared with published standardised mortality ratios reported for cohorts of workers with asbestosis. Since the ratios ranged from 6.3 to 9.1, the probability that lung cancer in such cases is due to asbestos is high regardless of lobe of origin. In many cohorts unstratified by the presence or absence of asbestosis the risk ratios are below one or both of these critical values. Since risk ratios are so high among workers with asbestosis, the ratios must be lower for workers without asbestosis than the overall ratios for unstratified cohorts. Therefore, the critical values may be useful in workers without asbestosis among such cohorts to estimate the upper limit of the probability that lung cancer in a given lobe is due to exposure to asbestos.

Asbestos↗
PubMed1988

The efficacy of antimicrobial treatment in Campylobacter pylori-associated gastritis and duodenal ulcer.

The efficacy of various antimicrobial and anti-ulcer agents on the elimination of Campylobacter pylori in duodenal ulcer patients was investigated. Ranitidine, cimetidine, pirenzepine, aluminium phosphate gel as well as combinations of H2-receptor antagonists or pirenzepine + penicillin V, ciprofloxacin, ofloxacin, phenyl-mercuryborate or rifampicin had no influence on C. pylori in vivo. Short term elimination of C. pylori was achieved in 3/15 patients treated with ranitidine + bacampicillin and in 1/5 treated with cimetidine + metronidazole. This elimination was accompanied by a significant reduction of polymorphonuclear infiltration of the antral mucosa. Development of bacterial resistance was observed in patients with additional quinolones, metronidazole and rifampicin but not in patients treated with betalactam antibiotics.

Anti-Bacterial Agents↗
PubMed1988

Smoking and pulmonary fibrosis.

A review of the relevant literature provides evidence that cigarette smoking causes microscopic diffuse interstitial pulmonary fibrosis in humans at autopsy. The association shows a dose-response relationship and the fibrosis is often severe. Experimental animal studies have confirmed these observations when the exposure to inhaled smoke was prolonged or heavy. Six published and one unpublished cross-sectional chest x-ray surveys of adults have shown low profusion of small irregular opacities related to smoking with a dose-response relationship when this has been studied. Although information on radiographic-pathologic correlation is deficient, these studies support the hypothesis that smoking causes diffuse interstitial pulmonary fibrosis which is radiologically visible with low profusion in low prevalence. The x-ray manifestations may be confused with early pneumoconiosis such as asbestosis.

Age Factors↗
PubMed1987

[3-year long-term therapy of recurrent duodenal ulcer with 400 mg cimetidine nocte].

253 patients were treated for 3 years with 400 mg cimetidine at night to prevent relapses of recently healed duodenal ulcers. The efficacy of maintenance treatment was evaluated on a life table basis. In contrast to previous studies not the first but the third symptomatic relapse was taken as the major criterium of treatment failure, an assumption, that better represents the everyday practical situation. Further endpoints for the life table calculation were: the wish of the patient to stop treatment after the first or second recurrence, the failure of a first or second recurrence to heal within 12 weeks and side effects. At 1, 2 and 3 years 5 +/- 2.4%, 16 +/- 4.6% and 20 +/- 5.2% respectively had to be considered as treatment failures. 4 patients presented with a bleeding relapse, none of which necessitated emergency operation. There were no irreversible side effects. This study demonstrates that treatment of recurrent duodenal ulcers with 400 mg cimetidine at night for 3 years is safe and improves considerably the quality of life of the majority of patients. The authors suggest that drug maintenance treatment should be offered before surgery is recommended.

Cimetidine↗
PubMed1987

Postoperative cardiac support with a pulsatile assist pump: techniques and results.

Since 1980 this group has employed a pulsatile assist pump(s) in 23 patients. Postoperative survival was 39% (9/23). In this group, 16 patients have required left ventricular support; 9 have been weaned from the pump, and 7 have survived (44%). Three patients required right ventricular support, and two have survived (66%). Four patients required biventricular assistance, but none survived. There have been four late deaths in this group. Of the five patients alive and well, all are New York Heart Association Class I or II. Important conclusions include the following: The pulsatile pump can adequately support the pulmonary or systemic circulation for a period of days; dramatic improvement in ventricular function is frequently observed in patients with univentricular failure; adequate right ventricular function is a major determinant of survival in a patient with pulsatile left ventricular support; preoperative cardiogenic shock and/or a prolonged time on cardiopulmonary bypass (CPB) predispose the patient to diffuse intravascular coagulation and a poor result; considerable information remains to be learned regarding the selection of assist pump candidates, optimal CPB techniques, and intraoperative identification of biventricular failure, which will further improve these results.

Adult↗
PubMed1987

Antigens of powdered pearl-oyster shell causing hypersensitivity pneumonitis.

We describe the identification and characterization of antigens of the pearl-oyster shell which caused hypersensitivity pneumonitis in a 42-year-old worker. He was occupationally exposed to the dust of this shell in the manufacture of different ornaments. In addition to a typical history, the diagnosis was confirmed through a workplace-related exposure test and high titres of antigen-specific IgG antibodies. By means of the immunoblot technique, several relevant antigens could be detected in the shell of the pearl-oyster. Control sera also contained immunoglobulins that bound to some electrophoretically separated bands; these could represent antibodies that react with lectin-like components in the shell in a nonimmunologic manner.

Adult↗
PubMed1987

In vitro and in vivo characterization of novel 8-methoxy derivatives of chlortetracycline.

The in vitro activities of three new 8-methoxychlortetracyclines, Sch 36969, 33256 and 34164 were compared to tetracycline, minocycline and doxycycline. Against aerobic Gram-negative rods Sch 36969 had a geometric mean MIC (GMM) of 4.2 micrograms/ml, about 8-fold more potent than Sch 33256, and similar to all the other compounds. Sch 36969 also had good activity against methicillin-resistant (GMM, 0.21 micrograms/ml) and -susceptible Staphylococci (GMM, 0.14 micrograms/ml), Streptococci (GMM, 0.06 micrograms/ml), and most anaerobic bacteria (GMM, less than 0.5 micrograms/ml). In general, Sch 36969 was similar to, or more potent than, all the other compounds tested. Serum levels of Sch 36969 in squirrel monkeys were 4-fold lower (AUC, 4.5 micrograms.hours/ml) than those of chlortetracycline (AUC, 16.1 micrograms.hours/ml). In mouse protection tests (PD50s) against various strains of bacteria, Sch 36969 was similar in activity to tetracycline, but up to 6-fold less active than chlortetracycline. The structure activity relationships for these new chlortetracyclines are described.

Animals↗
PubMed1987

Effects of low and high dose oral cimetidine on hormone serum levels in patients with peptic ulcers.

Luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (hPRL) and testosterone (T) were assayed in a total of 131 patients with peptic ulcer. Initial oral treatment was performed with 1000 mg cimetidine per day for 6 to 12 weeks. After healing was confirmed endoscopically, the patients were switched to a maintenance dose of 400 mg per day cimetidine for 3 years. Serum hormone levels before and during the two regimens were estimated in 48 male, 22 postmenopausal and 5 premenopausal subjects. Comparison between the two cimetidine doses was possible in 76 male, 44 postmenopausal and 6 premenopausal patients. In all patients hormone parameters assayed before therapy were within the normal ranges. FSH was noted to increase significantly in all but the premenopausal group but remained within the normal range. In contrast, hPRL declined significantly in all groups of subjects except for premenopausal females during cimetidine treatment. LH and T did not change during treatment and no differences of hormone serum levels were noted between the two regimens. Present data combine to suggest that an initial treatment with 1000 mg of cimetidine per day did not provoke hyperprolactinemia, and a switch from an initial high dose to a maintenance dose of 400 mg per day did not cause further changes in hormone serum levels. Changes of LH, FSH, hPRL and T recorded in the present study are too small to be considered responsible for possible endocrine disorders observed during cimetidine therapy.

Administration, Oral↗
PubMed1987

[Solid phase radioimmunoassay for the quantitative determination of antigen-specific IgG-antibodies in the serum of patients with farmer's lung].

In this study we have investigated a number of technical aspects of a sensitive solid-phase radioimmunoassay (microtitre-plate RIA) for the quantitative determination of antigen-specific IgG antibodies in the sera of patients suffering from farmer's lung. Microtitre-plates were coated with antigens of Aspergillus fumigatus, Micropolyspora faeni, Aureobasidium pullulans, Alternaria tenuis, Thermoactinomyces vulgaris and hay. Optimal antigen concentration and serum dilution were determined, the temperature-dependence of the assay and the kinetics of the binding of antibodies and protein A were studied. A comparison between glutaraldehyde-activated and non-activated microtitre-plates showed that the RIA with activated microtitre-plates produces values approximately 10-times higher than those with non-activated plates. However, the use of activated plates did not significantly increase the ratio between patient and control values.

Antibody Formation↗
PubMed1986

[New aspects of Crohn disease and ulcerative colitis: current diagnosis].

Differential diagnosis of inflammatory bowel disease includes careful history taking, microbiological stool tests and endoscopy. Radiological procedures are required only in patients with Crohn's disease in order to demonstrate small bowel lesions or fistulae. The clinical relevance of recent scintigraphic techniques (67-gallium-citrate, 111-indium granulocytes, 99m-technetium-sucralfate) needs further exploration. Careful follow-up of patients with ulcerative colitis and Crohn's disease is mandatory once the duration of symptoms exceeds 10 years, in view of the high risk of development of carcinoma. The search for severe dysplasia is difficult and time consuming. Certain additional tests promise to be of value in detecting early malignancy, but these are not yet suited for routine clinical follow up.

Colitis, Ulcerative↗