Plasma 5 alpha-dihydrotestosterone and testosterone in the bullfrog, Rana catesbeiana: stimulation by bullfrog LH.

Effects of purified bullfrog (Rana catesbeiana) LH and FSH on plasma levels of the androgens, testosterone (T), and 5α-dihydrotestosterone (DHT), were studied using adult male bullfrogs. Rana LH was considerably more potent than Rana FSH in stimulating increased plasma androgen levels in hypophysectomized and intact animals. Simultaneous injection of Rana FSH or ovine PRL with Rana LH, over a 10-day period, did not alter the LH-induced increase in plasma androgens. More DHT than T was present in plasma after LH injection. Castration abolished plasma DHT and greatly reduced plasma T. Results indicate that DHT is a major testicular steroid, and that testicular androgen secretion is stimulated primarily by LH in the bullfrog.     

Right-Sizing Technology in the Era of Consumer-Driven Health Care

Technology for modern clinical and public health microbiology laboratories has evolved at an impressive rate over the last two decades. Contemporary diagnostics can rapidly provide powerful data that can impact patient lives and support infectious disease outbreak investigations. At the same time, dramatic changes to health care delivery are putting new pressures on a system that is now focusing on patient-centric, value-driven, convenient care. For laboratories, balancing all these demands in a cost-contained environment remains a challenge. This article explores the current and future directions of diagnostics in our dynamic health care environment.     

Changes in serum high density lipoproteins in women on oral contraceptive drugs

Serum lipids, lipoproteins, and lipoprotein subfractions were measured in a group of 18 women aged 20 through 39 who were users of oral contraceptive drugs, and in 19 age-matched controls. Concentrations of the major lipid and lipoprotein classes were higher in the users, but the elevation was statistically significant only in the case of the high density lipoproteins. This increase was shown to be due to a highly significant increase (275 ± 9 vs. 223 ± 9 mg/100 ml, p < 0.005) in the denser high density lipoprotein subfraction (HDL₃). Levels of the other subfraction (HDL₂) were similar in users and controls. Thus, anovulatory steroids have selective effects on individual types of high density lipoproteins. Studies of such specific effects may help to further define the functional properties of the high density lipoproteins such as their apparent protective role in atherosclerosis.     

From screening to seeking care: removing obstacles in hypertension control.

Entry into the medical care system of patients screened for hypertension is a major problem faced by a control program. In a sequential screening project at a work site, 54 persons found to have mild to moderate hypertension were followed after initial medical referral. Using a pre-/post-test design, half received specially prepared health education materials and a follow-up visit to discuss these materials. Dependent measures included increased knowledge of hypertension and the making and keeping of medical appointments. At the end of 3 months, 56% of the experimental group, as compared with 26% of the control group, had received medical follow-up. Post-test knowledge scores were also significantly higher for those receiving the educational materials. The results are compared with those of other screening programs.     

Contrast sensitivity in children

We have used a spatial two-alternative, forced-choice staircase technique to measure contrast sensitivities for sinusoidally modulated gratings. Subjects, all of whom were untrained observers, consisted of children of ages 2–16 yr and adults. Our testing method was completely successful with children who were over 3.5 yr but failed with those below 2.5 yr. Mean contrast sensitivities of the youngest group from which data were obtained (2.5–4.5 yr) were 0.35 log units lower than those of adults. However, there was very little difference between these two groups in the middle range of spatial frequencies tested. A gradual increase with age of contrast sensitivities was found up to about 8 yr. This change is probably due to a combination of neural development and non-visual factors.     

Possible role of microtubules and associated proteases in organophosphorus ester-induced delayed neurotoxicity

Organophosphorus delayed neurotoxicants (phenyl saligenin cyclic phosphate and diisopropyl phosphorofluoridate) altered cyclic AMP (cAMP)-dependent phosphorylation and several other processes in brain homogenates and cytoplasmic microtubules. Phenyl saligenin cyclic phosphate slightly stimulated in vitro cAMP-dependent phosphorylation in brain homogenates of three species (rat, mouse and rabbit) that have been reported to be insensitive to delayed neurotoxicity, whereas it slightly decreased this phosphorylation in brain homogenates of three sensitive species (chicken, cow and pig) and in brain microtubules of chicken and pig. The microtubule-associated processes that were moderately inhibited by phenyl saligenin cyclic phosphate in sensitive species were: in vitro [3H]cAMP binding to protein kinase, in vitro assembly when tubulin rings were absent, and cAMP-dependent phosphorylation of microtubule-associated proteins (MAPs) both in vitro and on intracerebral administration of 32Pi. The endogenous proteases that degrade the high molecular weight MAPs were strongly inhibited in vitro by phenyl saligenin cyclic phosphate and diisopropyl phosphorofluoridate. In contrast, treatment of chickens with diisopropyl phosphorofluoridate remarkably decreased the in vitro stability of their brain cytoplasmic high molecular weight MAPs, perhaps by enhancing the MAPs-degrading protease activity. These findings indicate that the MAPs-protease system is a possible target for organophosphorus delayed neurotoxicants.     

Food Insecurity Is Associated with Body Dissatisfaction among Children in California

BackgroundFood insecurity affects 13 million children in the United States. Body dissatisfaction is also prevalent, affecting up to 46% of children. Both food insecurity and body dissatisfaction are associated with poor health outcomes, and both are associated with body weight and racial/ethnic disparities. The association between food insecurity and body dissatisfaction among children has not been examined.ObjectiveThe purpose of this study was twofold: to examine, in a sample of children in grades 4 through 8, the relationship of child food insecurity with body dissatisfaction and to gain an understanding of the interactive roles of body mass index (BMI), race/ethnicity, and sex in the relationship between food insecurity and body dissatisfaction.DesignThis was a cross-sectional study.Participants/settingThis study examined data obtained from 14,768 children in grades 4 through 8 from 54 public schools in California between 2014 and 2016.Main outcome measuresThe primary outcome of interest was body dissatisfaction (five items converted to a binary indicator), and the exposure of interest was child-reported food insecurity (three items converted to a binary indicator). Subsets of validated questionnaires were used to assess body dissatisfaction and food insecurity.Statistical analyses performedData were analyzed using multivariable logistic regression, and effect modification was examined by BMI category (underweight, normal, overweight, obese), race/ethnicity, and sex.ResultsIn this large and diverse sample, after adjusting for cofounders, children experiencing food insecurity, in all BMI categories and from all racial/ethnic backgrounds, had higher odds of body dissatisfaction than their food-secure counterparts. The strength of the relationship differed by BMI and race/ethnicity, with the strongest associations observed for African-American children (odds ratio=2.32; P<0.001) and children with a normal children (odds ratio=1.76; P<0.001).ConclusionsExperiencing food insecurity was associated with greater body dissatisfaction, with the magnitude of the association modified by BMI and race/ethnicity.