Destruction and reconstitution of the dictyosome in the chrysophycean flagellate,Poterioochromonas malhamensis,after heat-shock,and other heat-shock effects

Summary The viability of the chrysophycean flagellate,Poterioochromonas malhamensis, was examined after treatment of the cells with high temperatures. The fine structure of the cells was studied after heat-shock (42 °C, 16 minutes). Heat injury effects are visible at the nucleus, the chloroplast (distortion of the thylakoids), the mitochondria (increased occurrence of matrical crystalline inclusions) and, especially, at the dictyosome which is completely destroyed into some single vesicles and remnants of cisternae. Most damages are repaired within one hour; the reconstitution of the dictyosome takes 3–6 hours. It is inhibited severely by actinomycin D.The effect on the dictyosome reflects its labile position in the endomembrane system. The dependence of its reconstitution on protein synthesis indicates that membrane components are destroyed by the heat-shock.     

Blood levels of corticosterone, aldosterone, angiotensin and ACTH in rats after deafferentation of the tongue

The influence of tongue deafferentation on the plasma level of sodium homeostasis-controlling hormones has been studied. Using radioimmunoassay, high corticosterone and aldosterone plasma levels were discovered in rats with tongue deafferentation, as compared to sham-operated controls. ACTH and angiotensin I plasma concentrations in deafferentated rats were the same as in sham-operated rats. The role of emotional factors of taste perception in sodium homeostasis control is being discussed.     

Gender Differences in Mental Health Outcomes before,during, and after the Great Recession

We examined gender differences in mental health outcomes during and post-recession versus pre-recession. We utilized 2005-2006, 2008-2009, and 2010-2011 data from the Medical Expenditure Panel Survey. Females had lower odds of depression diagnoses during and post-recession and better mental health during the recession, but higher odds of anxiety diagnoses post-recession. Males had lower odds of depression diagnoses and better mental health during and post-recession and lower Kessler 6 scores post-recession. We conducted stratified analyses, which confirmed that the aforementioned findings were consistent across the four different regions of the U.S., by employment status, income and health care utilization. Importantly, we found that the higher odds of anxiety diagnoses among females after the recession were mainly prominent among specific subgroups of females: those who lived in the Northeast or the Midwest, the unemployed, and those with low household income. Gender differences in mental health in association with the economic recession highlight the importance of policymakers taking these differences into consideration when designing economic and social policies to address economic downturns. Future research should examine the reasons behind the decreased depression diagnoses among both genders, and whether they signify decreased mental healthcare utilization or increased social support and more time for exercise and leisure activities.     

Ultrastructural changes in the spleen of the natterjack,Bufo calamita,after antigenic stimulation

Summary In the present study comparative aspects of the ultrastructure of the spleen were analyzed in non-immunized and T-dependent antigen-challenged natterjacks, Bufo calamita. Special attention is focused on the role of the non-lymphoid components in the splenic immunoreactivity. Ten days after primary immunization with sheep erythrocytes, splenic lymphoid follicles increase considerably in number and size. By that time, lymphoblasts, medium and large lymphocytes abound in the periphery of the white pulp near the marginal zone. Meanwhile, in the red pulp numerous monocytes migrating across the sinusoidal walls apparently transform into giant, dendritic-like cells. Twenty days after immunization the splenic lymphoid follicles decrease in number, although certain reactivity persists and numerous plasma cells occur in the cell cords and sinusoids of the red pulp. These results are discussed comparatively with those reported in other lower vertebrates.     

Growth, morphogenesis, and virulence of Candida albicans after oral inoculation in the germ-free and conventional chick

Balish, Edward (Syracuse University, Syracuse, N.Y.), and A. W. Phillips. Growth, morphogenesis, and virulence of Candida albicans after oral inoculation in the germ-free and conventional chick. J. Bacteriol. 91:1736-1743. 1966.-The effects of intestinal bacteria on the multiplication, morphogenesis, and infectivity of Candida albicans in the alimentary tract were investigated by comparing results obtained in germ-free and conventional chicks after oral inoculation. This challenge resulted in the establishment of large numbers of the pathogen in the alimentary tract of each group of chicks; these numbers were increased in crop contents from challenged bacteria-free chicks wherein hyphae predominated over the yeast form. These animals also had lesions of the crop epithelium containing numerous hyphae and few yeast-like forms. In contrast, challenged conventional chicks receiving an adequate diet displayed no evidence of infection. Their alimentary tract contained the yeast form of C. albicans; no hyphae were seen. Although we found bacterial inhibition of C. albicans multiplication in the alimentary tract, this in itself did not seem to explain the resistance to intestinal candidiasis in our conventional chicks. We argued that this resistance to infection was due chiefly to the prevention of hyphal development in C. albicans by intestinal bacteria. C. albicans in the gut of our conventional chicks resulted in some increase in numbers of enterococci in contents from the crop. Increased pH values in contents from the gut of germ-free chicks were not clearly related to infection after challenge. The E(h) of the above crop contents were only slightly decreased in the germ-free crop. Thus the E(h) did not appear to be involved in susceptibility to infection. Invasion of the blood stream and kidneys of conventional chicks by the yeast form of C. albicans occurred in challenged animals receiving a purified diet which had been radiation-sterilized and stored for 6 months at room temperature (25 C). Their growth rate decreased and they became moribund; no hyphae were observed in tissues or intestine of these animals. Challenged bacteria-free chicks receiving the same diet were resistant to the above invasion, although they had crop lesions containing hyphae as described. The resistance of these chicks to systemic invasion was attributed to absence of intestinal bacteria competing for low levels of vitamins in the stored diet. Germ-free chicks had decreased levels of serum gamma-globulin which increased after challenge, whereas this value was unchanged in conventional birds after challenge.     

Perinatal mortality in Bavaria, Germany, after the Chernobyl reactor accident

As has been shown by the authors of a paper recently published in this journal, a deviation from a long-term trend in perinatal mortality within the former Federal Republic of Germany occurred in 1987, i.e. 1 year following the Chernobyl disaster. It is the aim of this study to make a comparison between the areas of the state Bavaria, Germany, with different fallout levels as well as between the observed and expected numbers of perinatal deaths relating to these areas. The expected numbers of perinatal deaths, defined as external standard, were derived from the remainder of the former FRG. Testing an a priori formulated hypothesis revealed no differences in the temporal development of perinatal mortality between the areas with different fallout levels and subsequent exposures. Including May 1986 into the analysis revealed a significant increase during the first 3 months after the accident, which is due to an excess in May alone. Since no elevated radiation risks for the last days in utero are known, the additional Chernobyl radiation exposure is not plausible as a causative agent. Further analyses on stillbirths showed an increase in Southern Bavaria during the first 2 years following the accident. Later on, the rates were comparable to the expected values again. Received: 23 January 1997 / Accepted in revised form: 4 April 1997