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Biomedical subjects

W Weiss

Publications and source records attributed to W Weiss.

At least 73 records · Page 4Linked to original sources
PubMed1995

The lack of causality between asbestos and colorectal cancer.

To evaluate a potential causal relationship between asbestos exposure and the risk of colorectal cancer, 30 cohort studies published in English were reviewed and analyzed. The latest report of each cohort up through 1993 was used. The outcome measure was the standardized morbidity (incidence) or mortality ratio (SMR). Summary SMRs were examined by type of cohort registration, type of work, type of asbestos, latency from onset of exposure to period of risk, and incidence only. The overall relative risk was 0.99 for all 30 studies. The evidence does not meet the important criteria for a judgment of causality because the relative risk is not consistently elevated, weak in the two studies with a statistically significant elevation of SMR, and limited data do not support a dose-response relationship.

Asbestos↗
PubMed1995

[Videocinematography and pre- and postoperative diagnosis of lip-maxillary-palatal clefts].

Videocinematography is a valuable tool in the diagnostic workup and planning of functional surgery in cleft patients. The high resolution and depiction of the finest mucosal structures in motion allow objective and dynamic assessment of the individual velopharyngeal function. A total of 170 cleft patients were examined by videocinematography, and the results were compared to nasoendoscopy and to the clinical examination. The marked superiority of this radiological technique with regard to clearness of depiction and ease of use is shown. It can therefore be recommended without reservation for the pre- and postoperative assessment of cleft patients.

Adolescent↗
PubMed1995

Gastric carcinoma arising from a hyperplasiogenic polyp with a diameter of less than 2 centimeters.

As there are only few reports on the occurrence of carcinoma in hyperplasiogenic polyps there is at present no general agreement concerning the malignant potency of these polyps in the stomach. In this paper we review the literature and present the unusual case of a patient who developed carcinoma in a hyperplasiogenic polyp with a diameter of 15 x 5 mm. Whereas in nearly all the reported cases cancer developed in polyps with a diameter greater than 2 cm our findings demonstrate that even in smaller polyps malignant changes have to be suspected.

Adenocarcinoma↗
PubMed1994

[Hyponatremic coma as the first symptom of a small cell bronchial carcinoma].

A 50-year-old man was admitted to hospital because of vertigo for 3 weeks. He was found to have severe hyponatraemia (107 mmol/l), which was rectified with sodium chloride infusions. Two weeks later he became agitated with confusion and hallucinations. Within a few hours he went into coma. At that time the serum sodium concentration had again fallen from 132 to 105 mmol/l. Repeated measurement revealed urinary osmolality (558 mosm/l) to be above that of serum (252 mosm/l), pointing to the syndrome of inadequate antidiuretic hormone secretion (SIADH) as the diagnosis. Lung tomography, performed because the patient had two bouts of pneumonia in quick succession, demonstrated enlarged hilar lymph nodes. Bronchoscopy revealed a tumour of about 1.0 cm diameter in the left main bronchus which histologically proved to be a small-cell bronchial carcinoma. Despite chemotherapy the tumour progressed and the SIADH also persisted. The patient died 9 months later of heart failure.

Bronchoscopy↗
PubMed1994

Five of six protein kinase C isoenzymes present in normal mucosa show reduced protein levels during tumor development in the human colon.

Protein kinase C (PKC) isoenzyme patterns were analyzed from human colonic epithelial cells of normal, premalignant and malignant origin. PKCs alpha, beta and zeta were found predominantly in the cytosol and the subtypes delta, epsilon and neta almost exclusively in the particulate fraction. Of the isoenzymes found beta, epsilon and neta were low in abundance and could only be detected after partial purification of cellular fractions on DE52-cellulose. Only PKC beta was similar in abundance in normal mucosa, premalignant and malignant colonic epithelial cells, while all other isoenzymes were decreased in abundance in tumor cells. The loss of PKC protein in tumor cells correlated with a loss in enzyme activity, as has been described before by other groups, especially affecting the Ca(2+)-dependent isoenzymes. On the other hand, activation of PKC by phorbol ester treatment in vivo was only possible in carcinoma cells (4/4) and a subset of adenomas (3/7). Normal human colonic epithelial cells did not respond to TPA treatment with either stimulation of PKC activity or translocation of cytosolic enzymes to the particulate fraction. Instead, TPA treatment resulted in a rapid loss of protein for the isoenzymes alpha, delta and to a lesser degree also beta. We assume that this reflects qualitative differences in response between normal and tumor cells, that may be due to the differences in isoenzyme distribution.

Adenoma↗
PubMed1994

Trimetrexate with leucovorin versus trimethoprim-sulfamethoxazole for moderate to severe episodes of Pneumocystis carinii pneumonia in patients with AIDS: a prospective, controlled multicenter investigation of the AIDS Clinical Trials Group Protocol 029/031.

Trimetrexate is a powerful inhibitor of the dihydrofolate reductase of Pneumocystis carinii. AIDS patients (n = 215) with moderate to severe P. carinii pneumonia were enrolled in a double-blind study of trimetrexate plus leucovorin versus trimethoprim-sulfamethoxazole (TMP-SMZ) for 21 days. By study day 10, study therapy failed because of lack of efficacy in 16% of patients assigned to TMP-SMZ and 27% assigned to trimetrexate (P = .064), and the PAO2-PaO2 improved significantly faster with TMP-SMZ. By study day 21, failure rates were 20% with TMP-SMZ and 38% with trimetrexate (P = .008), with respective mortality rates of 12% and 20% (P = .088). By study day 49, the difference in mortality (16% vs. 31%) was significant (P = .028). The cumulative incidence of serious and treatment-terminating adverse events including hematologic toxicities was less with trimetrexate (P < .001). Thus, trimetrexate plus leucovorin was effective, albeit inferior to TMP-SMZ, for moderately severe P. carinii pneumonia but was better tolerated than TMP-SMZ.

AIDS-Related Opportunistic Infections↗
PubMed1993

Electrophoretic characterization of wheat grain allergens from different cultivars involved in bakers' asthma.

In order to identify and characterize the wheat grain allergens involved in bakers' asthma, proteins were sequentially extracted from whole-meal flour. The polypeptide composition of the individual solubility fractions (albumin/globulin, gliadin and glutenin) was analyzed by sodium dodecyl sulfate-gel electrophoresis (SDS-PAGE), and high-resolution two-dimensional gel electrophoresis with immobilized pH gradient 4-9 in the first dimension (IPG-Dalt). The resolved polypeptides were transferred onto an immobilizing polyvinylidene difluoride membrane and incubated with a pooled serum from four asthmatic bakers. Bound IgE was demonstrated by autoradiography using 125I-labeled anti-human IgE. Our study demonstrated that the serum of the bakers allergic to flour contained IgE antibodies which bound to numerous polypeptides of all three solubility fractions. The highest percentage of IgE binding was observed with certain albumin and/or globulin polypeptides, whereas the gliadins and glutenins exhibited considerably less allergenicity. SDS-PAGE revealed that the protein which bound the highest percentage of IgE from the sera of the allergic bakers is a 27 kDa albumin. More detailed investigations using IPG-Dalt demonstrated that this allergen is not a single polypeptide but consists of several polypeptide spots that differ in their isoelectric points. Quantitative studies using computer-assisted laser densitometry revealed that the amount of patients' IgE bound by these particular polypeptides differed considerably between the seven wheat cultivars examined, ranging from 13% to 53% of the total radioactive uptake.

Albumins↗
PubMed1993

The efficacy of short-term gonadotrophin-releasing hormone agonists versus human chorionic gonadotrophin to enable oocyte release in gonadotrophin stimulated cycles.

One of the reasons for failure to conceive following human menopausal gonadotrophin (HMG) therapy may be due to non-release of oocytes from the follicles. We hypothesized that by using a gonadotrophin-releasing hormone agonist (GnRHa) for a short duration, endogenous release of luteinizing hormone and follicle stimulating hormone may enable oocyte release to occur, similar or superior to the effect of human chorionic gonadotrophin (HCG). This study attempted to compare the efficacy of HCG versus the GnRHa leuprolide acetate to release oocytes and achieve pregnancies and to compare the effectiveness of leuprolide acetate versus a combination of HCG with HMG to release oocytes. Unfortunately due to lack of prior data, many patients preferred to reject leuprolide acetate in favour of HCG, resulting in three times as many patients being treated with HCG in cycle 1; 78.2% of oocytes were released following leuprolide acetate versus only 55.7% with HCG. Interestingly, 87.5% of those females in whom oocyte release failed in cycle 1 with HCG did indeed release with leuprolide acetate in cycle 2, but none of these previous failures released with HCG in cycle 2. Pregnancy rates were equal in those women releasing oocytes, whether treated with HCG or leuprolide acetate. These preliminary data justify a larger randomized study.

Chorionic Gonadotropin↗