Influence of the ventral hippocampal formation on plasma vasopressin, hypothalamic-pituitary-adrenal axis, and behavioral responses to novel acoustic stress

The ventral hippocampal formation (vHF) seems to constrain diverse responses to psychological stimuli, and disruption of this function may underlie severe neuropsychiatric diseases. In particular, the ventral subiculum inhibits hypothalamic-pituitary-adrenal axis (HPA) activity following psychological, but not systemic, stressors. Despite the difficulty in interpreting such HPA responses, they have been relied upon to further characterize vHF function, because increased HPA axis activity is implicated in neuropsychiatric disturbances, and reliance on behavioral and cognitive data is even more problematic. Plasma arginine vasopressin (pAVP), which is inhibited by psychological stimuli and is also implicated in diverse neuropsychiatric diseases, provides a less ambiguous measure of CNS function. To test if its inhibition by psychological stress is also mediated by the vHF, we conducted two studies. In the first, pAVP and behavioral responses to novel acoustic stress were assessed in rats with bilateral excitotoxic lesions of the ventral subiculum and the ventral hippocampus. The subiculum lesions blocked the fall in pAVP and enhanced escape behaviors, whereas the hippocampal lesions produced responses intermediate to those in the subiculum-lesioned and control rats. In the second study, the pAVP response was similarly blocked by small lesions restricted to those vHF subfields which project to the neuroendocrine hypothalamus, compared to the response in animals with lesions in other vHF subfields. These results indicate that discrete projections from the vHF inhibit the pAVP response to psychological stimuli, and suggest that pAVP may provide a reliable probe of vHF activity.     

Assessment of fetal behavior and general movements by four-dimensional sonography

The aim of this paper was to review the clinical applications of four-dimensional ultrasonography in the assessment of fetal behavior. With the use of a computerized database, articles on three-dimensional ultrasonography were reviewed. Several applications of dynamic three-dimensional ultrasonography have been reported, including imaging of fetal movements, facial expression and fetal hand movements. The importance of the assessment of fetal behavior by four-dimensional sonography is stressed. Four-dimensional sonography seems to be a useful imaging tool for clinical problem solving in perinatology, especially in observing the development of the central nervous system in utero.     

Continuous exposure to dibromoacetic acid delays pubertal development and compromises sperm quality in the rat.

Previously our work on the haloacid by-products of drinking water disinfection focused on adult exposures. Herein we evaluate the consequence of continuous exposure to dibromoacetic acid (DBA) via drinking water through reproductive development into adulthood. An initial study in which offspring were exposed from gestation day (GD) 15 through adulthood revealed significant delays in preputial separation and vaginal opening, dose-related decreases in the fertility of cauda epididymal sperm, and dose-related diminutions in the sperm membrane protein SP22. Subsequent studies consisted of groups in which exposure ceased on postnatal day 21 (PND 21) versus adulthood. For each exposure, animals were evaluated after puberty (PND 56) as well as at adulthood (PND 120). Exposure to 4, 40, or 400 ppm DBA from GD 15 through PND 21 failed to result in any significant reproductive alterations. By contrast, continuous exposure until adulthood resulted in dose-related alterations consistent with those observed in the dose-finding study. Preputial separation and vaginal opening were delayed 4 and 3 days in males and females exposed to 400 ppm (76.3 mg/kg) DBA. This was associated with increased responsiveness of both the testis and ovary to hCG ex vivo; hCG-stimulated testosterone production by testicular parenchyma on PND 56 was increased at 4 ppm (0.6 mg/kg) DBA and higher. Finally, the quality of proximal cauda epididymal sperm was compromised by continuous exposure to DBA. The sperm membrane proteome was altered in a dose-related manner with SP22, and one of its charged variants, diminished at 40 ppm (3.6 mg/kg) DBA and higher. As more sensitive endpoints are evaluated, lower effect levels can be attributed to haloacid exposure. We are now extending our evaluations to epidemiology studies designed to evaluate sperm quality in men exposed to varying levels of disinfection by-products.     

Rapid diagnosis of glucocorticoid suppressible hyperaldosteronism in infants and adolescents

Glucocorticoid suppressible hyperaldosteronism (GSH) is an uncommon form of dominantly inherited hypertension. Presentation with hypertension and complications such as stroke in early life are well recognised. The use of a simple genetic test carried out on blood or placenta facilitates the detection of infants and children with GSH before the development of hypertension, allowing prompt treatment of hypertension if it occurs, and an opportunity to study the effects of growth and environmental influences on the progression of the condition.     

Ovarian hyperthecosis associated with fatty liver disease

Both cirrhosis and chronic active hepatitis have been reported in patients having ovarian hyperthecosis. This case report now documents histologically verified coincidental fatty liver disease along with ovarian hyperthecosis in a patient having an 8-year evolution of abnormal liver tests, hirsutism, and irregular menses.     

The effects of in vitro exposure to the neurotoxins sarin (GB) and soman (GD) on unscheduled DNA synthesis by rat hepatocytes

Large amounts of the nerve agents, sarin (GB) and soman (GD), are part of the military chemical arsenal and small amounts are on hand in numerous U.S. research laboratories. Thus, there is a potential for accidental occupational exposure to these compounds. As part of a study of mutagenic, reproductive and subchronic effects of these agents, we measured unscheduled DNA repair synthesis in isolated rat hepatocytes after exposure to GBI (stabilized with tributylamine), GBII (stabilized with diisopropylcarbodiimide) or GD. This was done to determine whether these agents or their metabolites directly damage DNA or their related proteins. Each agent was assayed at least once over concentrations ranging from 3.0 X 10(-4) to 2.4 X 10(-3) M for GBI and GBII and 2.3 X 10(-4) to 1.8 X 10(-3) for GD and at least 3 times at 2.4 X 10(-3) M for GBI and GBII and 1.8 X 10(-3) M for GD, added as 20% of the culture medium. In all assays, no increase in the level of DNA synthesis was observed. On the contrary, significant decreases in repair synthesis were seen in hepatocytes exposed to GBI or GBII. The decreases in DNA synthesis seen in response to GD were less marked and not significant. These observations were not related to cell death, since 8 of 10 assays performed showed no significant decrease in the amount of DNA present in cultures exposed to the nerve agents compared to the negative controls. Our results suggest that the agents GBI, GBII and GD may either inhibit the repair of DNA or protect DNA from damage.     

Participatory Systems Mapping for Municipal Prioritization and Planning

Rapidly growing cities face new and compounding health challenges, leading governments and donors to seek innovative ways to support healthier, more resilient urban growth. One such approach is the systems mapping process developed by Engaging Inquiry (EI) for the USAID-funded Building Healthy Cities project (BHC) in four cities in Asia. This paper provides details on the theory and methods of the process. While systems mapping is not new, the approach detailed in this paper has been uniquely adapted to the purpose of municipal planning. Strategic stakeholder engagement, including participatory workshops with a diverse group of stakeholders, is at the core of this approach and led to deeper insights, greater buy-in, and shared understanding of the city’s unique opportunities and challenges. This innovative mapping process is a powerful tool for defining municipal priorities within growing cities across the globe, where the situation is rapidly evolving. It can be used to provide evidence-based information on where to invest to gain the biggest impact on specific goals. This paper is part of a collection in this issue providing a detailed accounting of BHC’s systems mapping approach across four project cities.     

Glycogen metabolism in an amphibian retina

The rate of incorporation of [3H]glucose into glycogen was determined in bullfrog retina incubated in vitro in dark and in the light. The rate of incorporation for glucose was found to be approximately two-fold greater in the dark than in the light, 0.108 vs. 0.061 nmol mg-1 protein min-1, respectively. The turnover rate for glycogen was found also to be approximately two-fold greater in the dark than in the light, 0.051 vs. 0.027% min-1, respectively.