Hep G2 cells as a resource for metabolic studies: lipoprotein, cholesterol, and bile acids

Hep G2, a liver cell line derived from a human hepatoblastoma that is free of known hepatotropic viral agents, has been found to express a wide variety of liver-specific metabolic functions. Among these functions are those related to cholesterol and triglyceride metabolism. Confluent Hep G2 monolayers express normal low-density lipoprotein (LDL) receptors and continue to internalize and metabolize chylomicrons, very low-density lipoproteins (VLDL), LDL, and high-density lipoproteins. In lipoprotein-free medium, apolipoproteins A-I, A-II, B, C, and E accumulate in the medium together with cholesterol, cholesteryl ester, triglyceride, and all the primary bile acids. The regulation of their synthesis and secretion is not fully known and their interrelationships have not been established. Because Hep G2 cells express these and other components of cholesterol and triglyceride metabolism, they are a microcosm for studying the central role of the liver.     

Effects of opioid blockade with nalmefene in older impotent men

We evaluated the effect of the opioid antagonist nalmefene on the HPG axis and on food consumption in 14 older impotent men. These patients had low to low normal mean serum testosterone values and normal gonadotrophin levels on screening evaluation. Normal response to GnRH was demonstrated in all the men. The protocol called for 24 hours of evaluation before and during administration of nalmefene 2.0 mg IV every 8 hours for 3 doses. During each 24 hour period, the following determinations were made: serum testosterone, FSH, and LH by five separate determinations between 8 AM and noon; 8 AM and 11 PM serum cortisols; 24 hour urine collections for free cortisol; and nocturnal penile tumescence (NPT). Food consumption was measured from 4 PM to 10 AM during the two periods. Nalmefene resulted in significant rises in testosterone, LH, and FSH. Nalmefene significantly elevated morning and evening cortisol measurements in all the patients. Nalmefene decreased total calorie consumption, principally by decreasing fat consumption. There was no effect on NPT. We conclude that in older impotent men, nalmefene acutely increases activity of the HPG axis and decreases calorie intake predominantly by decreasing fat consumption.     

Species-area curves and estimates of total species richness in an old-field chronosequence

Average species-area curves were generated for vascular plants in 20 old-fields that were sampled in 1983, 1989, and 1994. These curves were fit with a saturating function to estimate total species richness for each old-field. Additional estimates of total species richness were generated by fitting the same saturating function to subsets of the species area curves and with a first-order jackknife procedure. Estimates of total species richness were strongly correlated with observed species richness. There was limited evidence suggesting that greater sampling was necessary to identify the same proportion of species in older, more species-rich old-fields.     

The formation of a test system for assessing the safety of different types of pertussis preparations: their cytotoxic action on mouse thymocytes in vitro

The test for the evaluation of the toxicity of different types of pertussis preparations as manifested by their in vitro influence on mouse thymic cells (T test) has been finally worked out. The use of the T test has made it possible to reveal the nonstandard character of the production lots of adsorbed diphtheria-pertussis-tetanus vaccines, both whole-cell vaccine and Japanese acellular vaccine. The degree of the in vitro damaging action of pertussis preparations on mouse thymic cells greatly depends on the residual content of Bordetella pertussis nontoxoidized toxin which, in contrast to B. pertussis lipopolysaccharide and filamentous hemagglutinin, produces pronounced cytotoxic action on mouse thymic cells.     

Vaccination status of infants discharged from a neonatal intensive care unit.

OBJECTIVE: To determine the vaccination rate among infants discharged from a neonatal intensive care unit (NICU) and factors affecting that rate. DESIGN: Cross-sectional survey conducted when the children were 12 to 18 months of age. SETTING: NICU at the Royal University Hospital, Saskatoon, Sask. PARTICIPANTS: All 395 infants discharged from the NICU between Jan. 1 and June 30, 1992. MAIN OUTCOME MEASURES: Vaccination rate, ethnic background (native or non-native), place of residence (urban or rural), health status (number of days spent in the NICU), reasons for delay in or incomplete vaccinations (those involving parents'' responsibility, infant illness or contraindications). RESULTS: Of the 395 infants, 20 (5.0%) had died and incomplete information was available for 30 (7.6%). Complete data were available for 345 (87.3%). Of the infants for whom data were available, 8 (2.3%) had never been vaccinated and 142 (41.2%) had a delayed vaccination schedule or had not completed their scheduled vaccinations. Only 195 (56.6%) of the infants had received a full vaccination series. Non-native ethnic background was a predictor of completed vaccinations (odds ratio [OR] 5.40, 95% confidence interval [CI] 3.05 to 9.52). In a univariate model, urban area of residence was not a significant predictor of vaccination status, but when ethnic background was controlled for in a multivariate logistic regression analysis, urban area of residence was found to be inversely associated with completed vaccinations (OR 0.34, 95% CI 0.15 to 0.79). The number of days the child had spent in the NICU was not a significant predictor of vaccination status. CONCLUSION: The vaccination rate of infants discharged from the NICU is not optimal. Urban native children appears to be at risk of not being vaccinated. Non-native infants are five times more likely than native infants to have completed all of their scheduled vaccinations. Methods to improve the rate of completed vaccinations, especially for native children, must be sought and tested.