Plutonium and the risk of cancer. A comparative analysis of Pu-body burdens due to releases from nuclear plants (Chelyabinsk-65, Gomel area) and global fallout

Whether the same or distinct steroid sulphatases (STS) are involved in the hydrolysis of alkyl and aryl steroid sulphates remains controversial. We have examined the ability of a placental steroid sulphatase to hydrolyse oestrone sulphate and/or dehydroepiandrosterone sulphate (DHA-S) by expressing the enzyme in COS-1 cells. Using either intact cells or broken cell preparations, the expressed sulphatase was found to hydrolyse both oestrone sulphate and DHA-S. The catalysis of oestrone sulphate and DHA-S by the expressed sulphatase was almost completely abolished by the steroid sulphatase inhibitor, oestrone-3-O-sulphamate. It is concluded that both alkyl and aryl steroid sulphates can be hydrolysed by the same steroid sulphatase.     

Processing of global and local visual information and hemispheric specialization in humans (Homo sapiens) and baboons (Papio papio).

Global precedence was examined in 8 baboons and 14 humans using compound stimuli presented in the left visual hemifield (LVF) or the right visual hemifield (RVF). Humans showed a global advantage and global-to-local interference. Baboons showed a local advantage and no interference. For humans and baboons, a LVF advantage appeared for global matching and an insignificant RVF advantage appeared for local matching. The local advantage in baboons still emerged when the memory load of the task was removed and when the local elements were connected by lines or were adjacent. Moreover, global precedence in humans persisted with unfamiliar forms. Species differences suggest that global precedence is not a universal trait and that this effect in humans does not have a purely perceptual or sensory basis. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Preservation of global cardiac function in the rabbit following protracted ischemia/reperfusion using monophosphoryl lipid A (MLA)

Monophosphoryl lipid A (MLA), a derivative of the minimal substructure of lipopolysaccharide (lipid A) possesses immunomodulatory activity of the parent lipid A yet enjoys reduced toxicity. It has previously been reported that pretreatment with MLA reduces myocardial infarct size and stunning in dogs following ischemia and reperfusion. The aim of this study was to evaluate the ability of monophosphoryl lipid A (MLA) to preserve global cardiac function and peripheral hemodynamics in a rabbit model of prolonged regional ischemia (90 min), and reperfusion (6 h). An evaluation of potential mechanisms by which MLA may preserve cardiac function was also undertaken. Single dose pretreatment with MLA (35 micrograms/kg i.v.) 24 h prior to ischemia resulted in significant improvement in left ventricular developed pressure, dP/dt, rate-pressure product and mean arterial pressure during reperfusion (P < 0.05 v control). Although in this model of prolonged ischemia MLA pretreatment did not reduce infarct size (54.5 +/- 11.4% in control v 63.3 +/- 8.3% in MLA, P = N.S.), evaluation of myocardial adenylate and adenosine catabolite pools at the end of ischemia indicated a preservation of ATP and ADP and a decreased production of downstream adenosine catabolites including inosine, xanthine and uric acid. Adenosine kinase, but not 5'-nucleotidase (5'-NTase) or adenosine deaminase activity determined following reperfusion was 76% and 60% higher (P < 0.05) in non-risk and post-ischemic myocardium of MLA pretreated rabbits compared with controls. Although there was a trend toward lower tissue myeloperoxidase activity in post-ischemic myocardium from treated rabbits, the results were not significantly different from control animals. These results suggest that a 24-h pretreatment with MLA, without further treatment during ischemia or reperfusion was associated with: (1) preservation of global myocardial function during reperfusion; (2) preservation of myocardial high energy adenylates and reduced formation of adenosine catabolites during ischemia; (3) elevated myocardial adenosine kinase activity. Increased recycling of adenosine to phosphorylated nucleotides may result from MLA's affect on adenosine kinase, which could explain the drugs effect on adenylate and adenosine metabolite pools.     

Clinical study of disorders of eye movements (voluntary and following) after acute vascular accidents involving the cerebral hemispheres (author's transl)

Voluntary eye movements and following movements have been assessed on a 3 point scale in 33 cerebrovascular patients, examined immediately after the stroke and in 52 patients examined 6-9 days after the stroke. The two types of movements were found to be impaired to the same extent in the majority of patients, especially those with severe neurological deficits. The "agreement index" between them, though high, was significantly inferior to 1. This suggests that voluntary and following movements are subserved by adjacent, but not identical neuronal structures. The available neuro-radiological evidence points to the parieto-temporal cortex as the area critically involved in eye movement disorders.     

The relative importance of global and local landmarks in navigation by Columbian ground squirrels (Spermophilus columbianus).

In order to survive, small burrowing mammals need to remember the locations of escape burrows. Therefore, it is important to know what types of landmarks are used to aid navigation in the wild. The author tested the ability of free-ranging Columbian ground squirrels (Spermophilus columbianus) to locate escape burrows when local (e.g., vegetation pattern, local relief), global (e.g., forest edge, mountain outline), or both types of landmarks were obstructed. Results suggest that squirrels need both local and global landmarks of the environment for successful navigation, and that the upper portion of the horizon is especially important for orientation. Moreover, the lack of information from one type of landmark (local or global) cannot be completely compensated by the other type. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic sequelae of the accident at the Chernobyl nuclear power plant in house mice (Mus musculus)

Genetic disorders were studied in house mice caught from 1986 to 1993 in areas contaminated by radionuclides after the Chernobyl disaster. Dose rates on soil surface ranged from 0.02 to 200 mR/h. Frequency of reciprocal translocations in spermatocytes of the mice studied was relatively low, but increased with dose rate. In populations, frequency of mice heterozygous for recessive lethal mutations decreased with time after the accident. The data obtained allow us to assume that induced mutations may lead to elimination of germ cells and decreased viability in mice heterozygous for the mutations. These processes result in removing excess mutations from the population.     

Antimicrobial characteristics of quinupristin/dalfopristin (Synercid at 30:70 ratio) compared to alternative ratios for in vitro testing

Quinupristin/dalfopristin is a new streptogramin combination that occurs at a natural ratio and formulation of 30:70. Rapid metabolism of the dalfopristin component to RP 12536 in vivo puts in question the validity of in vitro test of spectrum with the parent combination. In studies of quinupristin with both dalfopristin and RP 12536, a wide range of ratios (30:70, 50:50, 70:30) were tested by reference MIC and MBC tests. No significant potency differences were observed between combination ratios or metabolic components when testing 256 bacterial strains. Quinupristin/dalfopristin or quinupristin/RP 12536 remained active, by bactericidal action against many staphylococci and Streptococcus ssp. Enterococcus faecium strains were susceptible (MIC90, 2 micrograms/ml; static effect only) to the streptogramin, but E. faecalis, Pasteurella multocida, Pediococcus ssp., Haemophilus influenzae, and Bacteroides fragilis were generally less susceptible (MIC90, > or = 8 micrograms/ml). The log phase inoculum was preferred for MBC and kill-curve tests with this combination. The 30:70 ratio in vitro susceptibility test of quinupristin/dalfopristin as used to date, seems to predict the potency and spectrum of this streptogramin accurately and all clinically important in vivo ratios of the injectable form or its major metabolites. Quinupristin/dalfopristin should be further investigated for clinical use against emerging resistant Gram-positive infections, especially penicillin-resistant streptococci and glycopeptide-resistant E. faecium that exhibit susceptibility in this investigation.     

Differential patterns of mental disorders among the homeless in Madrid (Spain) and Los Angeles (USA)

In this paper we compare rates of mental disorders (major depression, dysthymia, cognitive impairment, and schizophrenia) among homeless people in Madrid and Los Angeles (LA) and examine the ordering of the onset of both conditions (i.e., homelessness and mental disorders). In the Madrid study, 262 homeless persons were interviewed using the CIDI. In the LA study, 1563 homeless persons were interviewed with the DIS. To make an item-by-item comparison, we companied the databases from both studies to submit a single database to statistical analyses. Results showed no significant differences in DSM-III-R life-time prevalence rates of mental disorders between both samples. However, the Madrid sample showed higher 12-month prevalence rates of dysthymia and cognitive impairment as compared to the LA sample. Most subjects across both cities first experienced symptoms of their mental disorders before first becoming homeless. The only significant difference was that all of the depressed adults in Madrid experienced depression prior to first becoming homeless, whereas this was the case for only 59.1% of LA depressed homeless people. We discuss the reasons for these cultural differences and their implications for cross-national public health research and intervention.     

A determination of the HDO/H2O ratio in comet C/1995 O1 (Hale-Bopp)

Deuterated water (HDO) was detected in comet C/1995 O1 (Hale-Bopp) with the use of the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. The inferred D/H ratio in Hale-Bopp's water is (3.3 +/- 0.8) x 10(-4). This result is consistent with in situ measurements of comet P/Halley and the value found in C/1996 B2 (Hyakutake). This D/H ratio, higher than that in terrestrial water and more than 10 times the value for protosolar H2, implies that comets cannot be the only source for the oceans on Earth.     

Papillary thyroid carcinoma oncogene (RET/PTC) alters the nuclear envelope and chromatin structure

Current evidence suggests the papillary thyroid carcinoma oncogene (RET/PTC) generates papillary thyroid carcinomas in one genetic step. We tested a resulting prediction that RET/PTC expression in thyroid epithelium should be sufficient to cause the changes in nuclear morphology diagnostic of this tumor. Primary cultures of human thyroid epithelial cells were infected with a RET/PTC retroviral construct. Morphological scoring by two independent cytopathologists shows RET/PTC expression by immunohistochemistry to be highly associated (p < 0.0001) with an irregular nuclear contour and a euchromatic appearance compared with non-expressing cells in the same cultures. The altered nuclear morphology is not due to gene transfer or transformation per se as primary thyroid cell cultures infected with a retroviral H-RAS construct differ from RET/PTC-infected cells by showing round nuclear envelopes and coarser chromatin, as determined by the independent scoring of two cytopathologists (p < 0.0001). In addition, RET/ PTC-transfected cells appear to disperse, whereas RAS-transfected cells grow as discrete colonies. The results provide additional support for the hypothesis that RET/PTC is sufficient to cause papillary thyroid carcinomas. A signaling pathway downstream of RET/ PTC leads to restructuring of the nuclear envelope and chromatin, and the signal does not depend entirely, if at all, on a RAS pathway.     

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the sediments of an Italian drinking water reservoir

The concentration of 9 polychlorinated biphenyls (PCB 28, 52, 101, 151, 153, 170, 180, 183 and 194) and of 6 micropollutants commonly classified as organochlorine pesticides, or OCPs (alpha-HCH, beta-HCH, gamma-HCH, p,p'-DDT, p,p'-DDE and p,p'-DDD), was determined in 22 sediment samples of lake Simbirizzi, an artificial reservoir supplying drinking water to the city of Cagliari (Sardinia, Italy). The quantification was performed by analysing purified sediment extract with HRGC-ECD. The average concentrations proved to be relatively low. In the case of p,p'-DDE, the contaminant with the highest concentration, a mean value of 0.84 ppb (micrograms/kg d.m.) was found. These relatively low concentrations and the comparison with data relating to other lakes suggest that, as far as PCBs and the majority of OCPs are considered, atmospheric inputs are likely to be the main source of contamination. Only for lindane (gamma-HCH) it is possible to assume a contribution from agricultural activities. The presence of its isomers (alpha-HCH and beta-HCH) was attributed to natural occurring reactions of the gamma-form.