Selective enhancement of spatial learning under chronic psychosocial stress

The hippocampus has long been proved to be implicated in several learning and memory processes. Being integrated into the limbic-hypothalamus-pituitary-adrenal axis, the hippocampus also plays an active role in the regulation of the stress response. Long lasting elevated levels of glucocorticoids resulting from a prolonged stress exposure affect hippocampal functions and structure, inducing learning and memory alterations and suppressing cell proliferation in the adult dentate gyrus. Here, adult male tree shrews (Tupaia belangeri) exposed to chronic psychosocial stress were tested repeatedly on a holeboard apparatus using two different learning tasks devised to evaluate hippocampal-dependent and hippocampal-independent cognitive function. We show that chronic stress enhanced learning in animals performing the hippocampal-dependent task, whereas no stress-induced effect was found in the hippocampal-independent task. Additionally, after five weeks of stress, cell proliferation was reduced in the hippocampal dentate gyrus. These results indicate that specific memory processes not only may remain intact, but indeed are facilitated by chronic stress, despite elevated cortisol levels and suppressed hippocampal cell proliferation.     

Wegener's granulomatosis in childhood

The authors reviewed the medical histories and radiological examinations of five pediatric patients with a histologic diagnosis of Wegener's granulomatosis (WG) seen over a six year period in whom a total of 22 thoracic CT scans were performed. Involvement of both the upper and lower respiratory tracts was seen in all patients at presentation. One patient had subglottic stenosis necessitating tracheotomy. Pulmonary hemorrhage occurred in three patients at initial diagnosis. Classic cavitary lung nodules were seen in two patients — one at initial presentation, the other at relapse. The plain radiographic lower respiratory tract manifestations of pediatric WG were protean both at initial presentation and during follow up. Similarly, disease expression was highly variable on thoracic CT examinations but, overall, multifocal parenchymal infiltrates with or without small peripheral nodules were the commonest thoracic CT manifestations. As a consequence of cytotoxic and corticosteroid therapy the long-term prognosis of WG has improved considerably in recent years. Knowledge of the varied patterns of the primary disease and potential for iatrogenic complications are necessary for successful radiologic assessment of pediatric patients with WG.     

Splenic necrosis in Wegener's granulomatosis

The CT appearance of asymptomatic splenic necrosis in a 11-year-old girl with Wegener's granulomatosis is presented. Sonography showed splenic inhomogeneity with patency of the splenic artery and vein. Follow-up CT showed lobulation and shrinkage of the spleen with return to a normal attenuation.     

Effect of oral application of an immunomodulating plant extract on Influenza virus type A infection in mice

The influence of the oral administration of an aqueous-ethanolic extract of a mixture of Thujae occidentalis herba, Baptisiae tinctoriae radix, Echinaceae purpureae radix and Echinaceae pallidae radix, on the course of Influenza A virus infection in Balb/c mice was investigated. The extract was administered to mice via the drinking water for 14 days starting 6 days before intranasal infection with Influenza A virus. The progress of infection was recorded during a time range of 21 days. Parameters for the evaluation of antiviral activity were survival rate and mean day to death. In a further set of experiments infected mice were sacrificed on defined days. Determination of consolidation score and virus titer were performed for each lung. The data show that the oral treatment with the extract induced a statistically significant increase in the survival rate, prolonged the mean survival time and reduced lung consolidation and virus titer. The experiments demonstrate that the plant immunomodulator given 6 days before exposure is a potent inhibitor of Influenza A virus pathology in vivo.     

Lebensstiländerungen zur Prävention koronarer Herzkrankheit

BACKGROUND: In developed countries arteriosclerosis is responsible for the majority of all deaths. With growing prosperity the life expectancy is increasing, and cardiovascular disease is becoming the primary cause of premature death. Most complications of arteriosclerosis occur unexpectedly. Because of the severe morbidity and high mortality prevention is the only true solution. CHANGES OF LIFESTYLE: Unhealthy nutrition, physical inactivity, overweight and smoking have been identified as the primary causes of arteriosclerotic vascular disease. Central obesity is responsible for the risk factors characterizing the metabolic syndrome. This is the result of inappropriate caloric intake and expenditure. In addition, the nutrients themselves can bear harmful consequences either indirectly by deteriorating risk factors like lipid parameters or by affecting directly the vessel wall. This can add to the deleterious effects of smoking. Evidently saturated fat is the single most decisive nutrient for atherosclerotic vascular disease. Cholesterol and trans fatty acids act additive, while unsaturated fatty acids appear to be beneficial. However, total fat intake is an important determinant of the energy supply, which again influences body weight and composite. Physical activity can counteract, but appears to be beneficial by several additional ways. Quitting smoking is highly effective already within few years. Together with physical activity and healthy nutrition more than 80% of all cardiovascular events can be prevented. CONCLUSION: Preventive medicine needs to focus on lifestyle changes because they are feasible and highly effective. A nutrition low in total fat primarily by avoiding saturated and trans fatty acids, but rich in carbohydrates and fiber is recommended. Daily physical activity in any preferred way should be encouraged, and quitting smoking needs to be strongly emphasized.     

Contraceptive steroids influence the hemostatic activation state in healthy men

Hormonal contraception for men requires administration of testosterone and gestagens. The effects of a long-acting testosterone ester and 2 different progestins on hemostatic activation parameters were studied in relation to cardiovascular risk. In phase 1, 7 healthy men aged 28-38 years received a single intramuscular injection of 200 mg norethisterone-enanthate (NET-EN) on Day 0. Plasma samples were obtained on Days 0, 14, 41, and 84. In phase 2, 3 groups of 14 healthy men aged 18-45 years received four injections (every 6 weeks) of 1000 mg testosterone undecanoate (TU), plus daily oral placebo or daily oral levonorgestrel (LNG, 250 microg); or four injections (every 6 weeks) of NET-EN. Treatment lasted 24 weeks. Plasma samples were obtained at weeks 0, 16, 24, and 52. All samples were assayed for levels of coagulation factors VIIc, VIIa, XIIc, and XIIa; prothrombin fragment F1+2 (F1+2); antithrombin; plasmin-alpha(2)-antiplasmin-complex (PAP); and fibrinogen. NET-EN alone led to a depletion of sexual hormones and a marked shift in hemostatic parameters with increasing levels of FXIIc, fibrinogen, antithrombin, and F1+2, whereas FVIIc and FVIIa levels decreased. PAP levels increased significantly. Opposite effects were seen in the TU/placebo group, with a significant down-regulation of fibrinolysis and the hemostatic turnover rate. Testosterone effects were attenuated by additional administration of gestagens. The effect of hormonal male contraception using long-acting testosterone esters with or without gestagens was significantly measurable within the hemostatic system. Down-regulation of the hemostatic system with testosterone alone may indicate an antithrombotic effect, whereas clinical consequences of an additional gestagen compound cannot be derived.     

Divalent Cations Modulate the Inhibitory Substrate Properties of Murine Glia-derived J1-160 and J1-180 Extracellular Matrix Glycoproteins for Neuronal Adhesion

J1-160 and J1-180 are developmentally late appearing J1 extracellular matrix glycoproteins derived from oligodendrocytes. They prevent adhesion of neurons (but not of astrocytes or fibroblasts) when offered as a substrate in mixture with laminin (Pesheva et al., J. Cell Biol., 109, 1765 - 1778, 1989). In the present study we have examined the influence of divalent cations on the inhibitory substrate properties of J1-160/180 glycoproteins towards adhesion of neurons. By metal chelate affinity chromatography, we show that J1-180, but not J1-160, binds Ca2+, while both J1 components are capable of binding Zn2+ and other divalent metal ions. Divalent cation binding was observed by gel filtration, aggregation assays with coated latex beads and electron microscopic examination to elicit aggregation of the molecules. Divalent cation binding also affects their non-permissive substrate properties towards neurons from early postnatal mouse cerebellum. Without divalent cations, J1-160 and J1-180 are inhibitory for substrate adhesion of neurons independently of the adhesive substrate present (laminin or poly-l-lysine). This effect is neutralized when J1-180 is preincubated with Ca2+ or Zn2+ prior to coating as substrate. In contrast, preincubation with Ca2+ ions does not affect the inhibitory substrate properties of J1-160 under these conditions. These observations show that J1-160/180 molecules may undergo self-aggregation in a divalent cation-dependent mechanism, which correlates with the neutralization of their inhibitory effect on neuronal adhesion. The aggregation state of the molecules may thus influence the process of myelination by a homophilic binding mechanism and determine the effectiveness of neurite extension during central nervous system development and under traumatic conditions in the adult.