The presence of glycosylated, biologically active chorionic gonadotropin in human liver

Whole extracts of normal human liver contain hCG-like material as determined by radioimmunoassay using antibodies to the beta subunit of the hormone. However, the extracts are biologically inactive, when analyzed by the in vitro rat Leydig cell assay for steroidogenesis. When subjected to Concanavalin-A-Sepharose chromatography, the radioimmunoassayable material was entirely lectin-bound. After elution with methyl-alpha-D-glucopyranoside, the lectin-bound fractions now displayed biological activity.     

Effects of low-level lead and arsenic exposure on copper smelter workers

An analysis of reported symptoms and their relationship with indicators of lead absorption--blood lead (Pb-B) and zinc protoporphyrin (ZPP)--and of arsenic absorption--urinary arsenic (As-U)--was undertaken among 680 active copper smelter workers. Lead and arsenic absorption in the copper smelter employees were characterized by the median values of 30.4 micrograms/dl for Pb-B, 41.5 micrograms/dl for ZPP, and 26 micrograms/L for As-U. Blood lead was 40 micrograms/dl or higher in 16.7% of cases, ZPP was 50 micrograms/dl or higher in 31.2%, and urinary arsenic was 50 micrograms/L or higher in 16.4% of currently active copper smelter workers. The number of reported symptoms (from a total of 14 symptoms) increased with ZPP levels; the relationship with Pb-B was less marked. Arsenic contributed relatively little. Mean Pb-B, ZPP, and As-U levels for subjects reporting each of the 14 symptoms were compared with those of subjects who did not report the symptoms. Mean Pb-B was found to differ significantly for one symptom, fatigue. Significant differences in mean ZPP levels were found for fatigue, sleep disturbances, weakness, paresthesia, and joint pain. Prevalence rates for these symptoms rose more markedly with increasing ZPP than with Pb-B levels. The results indicate a relationship between certain CNS and musculo-skeletal symptoms and increased lead absorption in this population. Adherence to exposure standards that preclude undue lead absorption and appropriate biological monitoring including ZPP levels, are necessary to prevent adverse, especially long-term, health effects.     

Alcohol consumption in developing countries. Review of available data for 3 African countries

The increasing alcohol consumption throughout the world appears to constitute an enduring public health problem. In developing countries, the consequences of such consumption should be considered as questions of both classical alcohol-linked pathology and of food balance. Available data for 3 countries in Africa (Burkina Faso, Congo, Cameroons) show an important growth in the industrial production of alcoholic beverages (mostly beer) over the last 20 years, while variation in traditional home production remains unknown. However, the lack of data on consumption does not permit a good appreciation of this problem.     

Hemodynamic collapse, geometry, and the rapidly paced upper limit of ventricular vulnerability to fibrillation by T-wave stimulation

There is an upper limit to the vulnerability (ULV) of the ventricles to fibrillation (VF) induced by T-wave stimuli. Across species, disease states, and pharmacological treatments, the ULV is correlated to the defibrillation threshold (DF50). However, one factor known to increase the ULV far above the DF50 is rapid pacing. In this article we test the hypothesis that this increase is owing to an accompanying hemodynamic collapse or geometric change. In 18 dogs, T-wave stimuli were delivered from transvenous defibrillating electrodes. The T-wave shock strength that induced VF 50% of the time (the ULV50) was measured using a 10-step Bayesian up-down protocol. T-wave stimuli were delivered after 15 paced beats at one of several rates: normal (80% of the R-R interval), rapid (the interval just fast enough to cause hemodynamic collapse), or 10 milliseconds greater than rapid (which did not cause hypotension). We measured the geometry of the left ventricle at the moment of T-wave stimulation using linear ultrasound. Rapid pacing significantly increased the ULV50 above the normal rate ULV (507 +/- 62.9 vs 379 +/- 70.6 V, P < .005, n = 18), even in the subset without hemodynamic collapse (505 +/- 84.4 vs 394 +/- 66.5 V, P < .005, n = 6). No significant geometric changes were noted between rapid (19.8 mm) and normal (20.6 mm, n = 6, P < NS) pacing, but QT interval reduction appears to correlate with the ULV50 (QT vs ULV50, r > 0, P < .01). Rapid pacing can dramatically increase the measured ULV50. The most likely cause is a concurrent change in the electrophysiology, eg, QT or APD, of the myocardium. As the only known factor to consistently alter the relationship between ULV and the DF50, rapid pacing offers a unique opportunity for the study of the link between defibrillation and ULV testing.