General and abdominal adiposity and risk of death in Europe

BACKGROUND

Previous studies have relied predominantly on the body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) to assess the association of adiposity with the risk of death, but few have examined whether the distribution of body fat contributes to the prediction of death.

METHODS

We examined the association of BMI, waist circumference, and waist-to-hip ratio with the risk of death among 359,387 participants from nine countries in the European Prospective Investigation into Cancer and Nutrition (EPIC). We used a Cox regression analysis, with age as the time variable, and stratified the models according to study center and age at recruitment, with further adjustment for educational level, smoking status, alcohol consumption, physical activity, and height.

RESULTS

During a mean follow-up of 9.7 years, 14,723 participants died. The lowest risks of death related to BMI were observed at a BMI of 25.3 for men and 24.3 for women. After adjustment for BMI, waist circumference and waist-to-hip ratio were strongly associated with the risk of death. Relative risks among men and women in the highest quintile of waist circumference were 2.05 (95% confidence interval [CI], 1.80 to 2.33) and 1.78 (95% CI, 1.56 to 2.04), respectively, and in the highest quintile of waist-to-hip ratio, the relative risks were 1.68 (95% CI, 1.53 to 1.84) and 1.51 (95% CI, 1.37 to 1.66), respectively. BMI remained significantly associated with the risk of death in models that included waist circumference or waist-to-hip ratio (P<0.001).

CONCLUSIONS

These data suggest that both general adiposity and abdominal adiposity are associated with the risk of death and support the use of waist circumference or waist-to-hip ratio in addition to BMI in assessing the risk of death.

Polymodal motion processing in posterior parietal and premotor cortex: a human fMRI study strongly implies equivalencies between humans and monkeys

In monkeys, posterior parietal and premotor cortex play an important integrative role in polymodal motion processing. In contrast, our understanding of the convergence of senses in humans is only at its beginning. To test for equivalencies between macaque and human polymodal motion processing, we used functional MRI in normals while presenting moving visual, tactile, or auditory stimuli. Increased neural activity evoked by all three stimulus modalities was found in the depth of the intraparietal sulcus (IPS), ventral premotor, and lateral inferior postcentral cortex. The observed activations strongly suggest that polymodal motion processing in humans and monkeys is supported by equivalent areas. The activations in the depth of IPS imply that this area constitutes the human equivalent of macaque area VIP.

Mutations in the gene encoding immunoglobulin mu-binding protein 2 cause spinal muscular atrophy with respiratory distress type 1

Classic spinal muscular atrophy (SMA) is caused by mutations in the telomeric copy of SMN1. Its product is involved in various cellular processes, including cytoplasmic assembly of spliceosomal small nuclear ribonucleoproteins, pre-mRNA processing and activation of transcription. Spinal muscular atrophy with respiratory distress (SMARD) is clinically and genetically distinct from SMA. Here we demonstrate that SMARD type 1 (SMARD1) results from mutations in the gene encoding immunoglobulin micro-binding protein 2 (IGHMBP2; on chromosome 11q13.2-q13.4). In six SMARD1 families, we detected three recessive missense mutations (exons 5, 11 and 12), two nonsense mutations (exons 2 and 5), one frameshift deletion (exon 5) and one splice donor-site mutation (intron 13). Mutations in mouse Ighmbp2 (ref. 14) have been shown to be responsible for spinal muscular atrophy in the neuromuscular degeneration (nmd) mouse, whose phenotype resembles the SMARD1 phenotype. Like the SMN1 product, IGHMBP2 colocalizes with the RNA-processing machinery in both the cytoplasm and the nucleus. Our results show that IGHMBP2 is the second gene found to be defective in spinal muscular atrophy, and indicate that IGHMBP2 and SMN share common functions important for motor neuron maintenance and integrity in mammals.

Antipsoriatic effect of fumaric acid derivatives. Results of a multicenter double-blind study in 100 patients

BACKGROUND

Psoriasis vulgaris may benefit from treatment with fumaric acid and/or its derivatives; however, because different preparations have been used, results have been contradictory and difficult to interpret.

OBJECTIVE

The purpose of this clinical trial was to evaluate the therapeutic value of fumaric acid derivatives.

METHODS

A randomized double-blind study was carried out in patients with psoriasis, comparing a well-characterized formulation of fumaric acid derivatives with placebo.

RESULTS

The results indicated statistically significant superiority of the fumaric acid derivatives over placebo. Adverse events (flush, gastrointestinal disturbances) were initially relatively frequent, but decreased thereafter.

CONCLUSION

Fumaric acid derivatives were found to be effective and safe in the treatment of psoriasis.

The direct thrombin inhibitor melagatran and its oral prodrug H 376/95: intestinal absorption properties, biochemical and pharmacodynamic effects

Suboptimal gastrointestinal absorption is a problem for many direct thrombin inhibitors. The studies presented herein describe the new oral direct thrombin inhibitor H 376/95, a prodrug with two protecting residues added to the direct thrombin inhibitor melagatran. Absorption properties in vitro: H 376/95 is uncharged at intestinal pH while melagatran is charged. H 376/95 is 170 times more lipophilic (octanol water partition coefficient) than melagatran. As a result, the permeability coefficient across cultured epithelial Caco-2 cells is 80 times higher for H 376/95 than for melagtran. Pharmacokinetic studies in healthy volunteers: H 376/95 is converted to melagatran in man. Oral bioavailability, measured as melagatran in plasma, is about 20% after oral administration of H 376/95, which is 2.7-5.5 times higher than after oral administration of melagatran. The variability in the area under the drug plasma concentration vs. time curve (AUC) is much smaller with oral H 376/95 (coefficient of variation 20%) than with oral melagatran (coefficient of variation 38%). Pharmacodynamic properties: H 376/95 is inactive towards human alpha-thrombin compared with melagatran [inhibition constant (K(i)) ratio, 185 times], a potential advantage for patients with silent gastrointestinal bleeding. In an experimental thrombosis model in the rat, oral H 376/95 was more effective than the subcutaneous low molecular weight heparin dalteparin in preventing thrombosis.

CONCLUSION

By the use of the prodrug principle, H 376/95 endows the direct thrombin inhibitor melagatran with pharmacokinetic properties required for oral administration without compromising the promising pharmacodynamic properties of melagatran.

A global representation of vitamin D status in healthy populations

PURPOSE

This paper visualizes the available data on vitamin D status on a global map, examines the existing heterogeneities in vitamin D status and identifies research gaps.

METHODS

A graphical illustration of global vitamin D status was developed based on a systematic review of the worldwide literature published between 1990 and 2011. Studies were eligible if they included samples of randomly selected males and females from the general population and assessed circulating 25-hydroxyvitamin D [25(OH)D] levels. Two different age categories were selected: children and adolescents (1-18 years) and adults (>18 years). Studies were chosen to represent a country based on a hierarchical set of criteria.

RESULTS

In total, 200 studies from 46 countries met the inclusion criteria, most coming from Europe. Forty-two of these studies (21 %) were classified as representative. In children, gaps in data were identified in large parts of Africa, Central and South America, Europe, and most of the Asia/Pacific region. In adults, there was lack of information in Central America, much of South America and Africa. Large regions were identified for which the mean 25(OH)D levels were below 50 nmol/L.

CONCLUSIONS

This study provides an overview of 25(OH)D levels around the globe. It reveals large gaps in information in children and adolescents and smaller but important gaps in adults. In view of the importance of vitamin D to musculoskeletal growth, development, and preservation, and of its potential importance in other tissues, we strongly encourage new research to clearly define 25(OH)D status around the world.

A high-throughput approach to identify genomic variants of bacterial metabolite producers at the single-cell level

We present a novel method for visualizing intracellular metabolite concentrations within single cells of Escherichia coli and Corynebacterium glutamicum that expedites the screening process of producers. It is based on transcription factors and we used it to isolate new L-lysine producing mutants of C. glutamicum from a large library of mutagenized cells using fluorescence-activated cell sorting (FACS). This high-throughput method fills the gap between existing high-throughput methods for mutant generation and genome analysis. The technology has diverse applications in the analysis of producer populations and screening of mutant libraries that carry mutations in plasmids or genomes.

Pharmacology and structure of P2Y receptors

P2Y receptors are G-protein-coupled receptors (GPCRs) for extracellular nucleotides. There are eight mammalian P2Y receptor subtypes (P2Y1, P2Y2, P2Y4, P2Y6, P2Y11, P2Y12, P2Y13, and P2Y14). P2Y receptors are widely expressed and play important roles in physiology and pathophysiology. One important example is the ADP-induced platelet aggregation mediated by P2Y1 and P2Y12 receptors. Active metabolites of the thienopyridine compounds ticlopidine, clopidogrel and prasugrel as well as the nucleoside analogue ticagrelor block P2Y12 receptors and thereby platelet aggregation. These drugs are used for the prevention and therapy of cardiovascular events. Moreover, P2Y receptors play important roles in the nervous system. Adenine nucleotides modulate neuronal activity and neuronal fibre outgrowth by activation of P2Y1 receptors and control migration of microglia by P2Y12 receptors. UDP stimulates microglial phagocytosis through activation of P2Y6 receptors. There is evidence for a role for P2Y2 receptors in Alzheimer's disease pathology. The P2Y receptor subtypes are highly diverse in both their amino acid sequences and their pharmacological profiles. Selective receptor ligands have been developed for the pharmacological characterization of the receptor subtypes. The recently published three-dimensional crystal structures of the human P2Y1 and P2Y12 receptors will facilitate the development of therapeutic agents that selectively target P2Y receptors. This article is part of the Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'.

Dietary patterns and their association with food and nutrient intake in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study

Dietary pattern analysis has recently received growing attention, as it might be more appropriate in studies of diet-disease associations than the single food or nutrient approach that has dominated past epidemiological research. Factor analysis is a technique which is commonly used to identify dietary patterns within study populations. However, the ability of factor solutions to account for variance of food and nutrient intake has so far remained unclear. The present study therefore explored the statistical properties of dietary patterns with regard to the explained variance. Food intake of 8975 men and 13 379 women, assessed by a food-frequency questionnaire, was aggregated into forty-seven separate food groups. Dietary patterns were identified by principal component analysis and subsequent varimax rotation. Seven factors were retained for both men and women, which accounted for about 31 % of the total variance. The explained variance was relatively high (>40 %) for cooked vegetables, sauce, meat, dessert, cake, bread other than wholemeal, raw vegetables, processed meat, high-fat cheese, butter and margarine. Factor scores were used to investigate associations between the factors and nutrient intake. The patterns accounted for relatively large proportions of variance of energy and macronutrient intake, but for less variance of alcohol and micronutrient intake, especially of retinol, beta-carotene, vitamin E, Ca and ascorbic acid. In addition, factors were related to age, BMI, physical activity, education, smoking and vitamin and mineral supplement use.

Estimating the distribution of usual dietary intake by short-term measurements

OBJECTIVE

To estimate the habitual dietary intake distribution in a population on the basis of repeated short-term measurements, especially of multiple 24 h diet recalls.

METHODS

Six different statistical methods were evaluated and compared. The comparison referred to theoretical assumptions, admitted data transformations, statistical foundations, available software packages, and applications to real data of dietary intake.

RESULTS

The Nusser method and a simplified version of it proposed in the paper have proved to be universally applicable methods for estimating the usual intake distribution for food groups and nutrients. Also, the Buck method seemed to be a robust estimation procedure suitable for the description of food consumption data, whereas the other considered methods were only applicable for log-normally distributed intake data or required a comprehensive data simulation. Characteristics of the estimated usual intake distribution were a decreased standard deviation, increased lower percentiles, and decreased upper percentiles compared to the observed sample distribution of individual means. Empirical results concerning total fat and vegetable intake in three different European consumption surveys showed that the estimated percentiles of the usual intake distribution did not depend markedly on the number of sampling days.

CONCLUSIONS

Repeated short-term measurements like 24 h diet recalls can be used to describe the habitual dietary intake distribution in food consumption surveys. Recommended is a sampling design of two non-consecutive sampling days. The sampling days of all participants should be selected in such a way that they cover all seasons and days of the week.

A dietary pattern protective against type 2 diabetes in the European Prospective Investigation into Cancer and Nutrition (EPIC)--Potsdam Study cohort

AIMS/HYPOTHESIS

The aim of this study was to identify a dietary pattern associated with diabetes-related biomarkers and to investigate whether this pattern is associated with the incidence of type 2 diabetes.

METHODS

A nested case-control study of 192 cases of incident type 2 diabetes and 382 control subjects matched for sex and age was conducted. All subjects were participants in the population-based European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study. Dietary pattern score was derived using intake data on 48 food groups as exposure variables and the biomarkers HbA1c, HDL cholesterol, C-reactive protein and adiponectin as response variables in reduced rank regression. The association of the score with diabetes risk was estimated by conditional logistic regression analysis.

RESULTS

A high score for the identified dietary pattern was characterised by a high intake of fresh fruit and a low intake of high-caloric soft drinks, beer, red meat, poultry, processed meat, legumes and bread (excluding wholegrain bread). Subjects with high scores had high plasma concentrations of HDL cholesterol and adiponectin and low plasma concentrations of HbA1c and C-reactive protein. After multivariate adjustment, the odds ratios for type 2 diabetes across increasing quintiles of the dietary pattern score were 1.0, 0.59, 0.51, 0.26 and 0.27, respectively (p = 0.0006 for trend).

CONCLUSIONS/INTERPRETATION

A high score for the identified dietary pattern is associated with a more favourable biomarker profile and a substantially reduced incidence of type 2 diabetes.

A procedure for phonetic transcription by consensus

A consensus transcription procedure is presented, and representative data are reported. The procedure includes explicit response definitions for mapping narrow phonetic transcription onto dichotomous, nonerror/error scores and 17 rules for obtaining consensus between two transcribers. The data include descriptive statistics for consensus rule use based on over 18,000 sounds transcribed during a normative study of speech sound acquisition in children aged 3-6 years. Validity and reliability issues in phonetic transcription are discussed.

easyLINKAGE: a PERL script for easy and automated two-/multi-point linkage analyses

We have generated the program easyLINKAGE that combines automated setup and performance of linkage analyses and simulation under an easy to handle graphical user interface for Microsoft Windows 2000/XP and standard UNIX systems. The program package supports two-point linkage analyses (FastLink v4.1 and SPLink v1.09), multi-point linkage analyses [GENEHUNTER v2.1, GENEHUNTER-PLUS with the emendation by Kong and Cox v1.2 (allele sharing modelling)] and the simulation package SLINK v2.65, and provides genome-wide as well as chromosomal postscript plots of LOD scores, NPL scores, P-values and other parameters.

AVAILABILITY

http://www.uni-wuerzburg.de/nephrologie/molecular_genetics/molecular_genetics.htm

SUPPLEMENTARY INFORMATION

Supplementary information is available on the website.

Effects of short photoperiods on puberty, growth and moult in the Djungarian hamster (Phodopus sungorus)

Male Djungarian hamsters were raised from birth in either long (16L:8D) or short (8L:16D) photoperiods. In 16L:8D, testes were large (about 400 mg) and showed full spermatogenesis from 31 days of age, the cauda epididymidis contained motile spermatozoa from 35 days and the accessory glands were large and reached their final size at about 60 days of age. In 8L:16D, testes remained small (about 15 mg) and undeveloped up to an age of about 130 days; they then developed to reach normal size and full spermatogenesis. In 16L:8D body weight increased steadily up to an age of about 160 days, but in 8L:16D body weight increase was slower and reached normal values, after a plateua at about 80 days, at about 190--260 days. Most animals in 8L:16D moulted into winter pelage, and then into the summer pelage; those in 16L:8D kept the summer pelage throughout.

A model of protein targeting mediated by immunophilins and other proteins that bind to hsp90 via tetratricopeptide repeat domains

We have shown recently that the immunophilins CyP-40 and FKBP52/hsp56 bind to a common site on hsp90 and that they exist in separate heterocomplexes with the glucocorticoid receptor (GR). FKBP52/hsp56 binds to hsp90 via its tetratricopeptide repeat (TPR) domains, it is not required for GR.hsp90 heterocomplex assembly, and it is thought to play a role in targeted movement of the GR. In this work we examine the hsp90 binding of four proteins (FKBP52/hsp56, CyP-40, p50, Mas70p) thought to be involved in targeted protein trafficking. FKBP52/hsp56 and CyP-40 (each with three TPRs), localize to the nucleus and nucleoli, respectively, and form relatively weak complexes with hsp90 that are competed by a CyP-40 fragment containing its three TPRs. The p50 component of the Src.hsp90 and Raf.hsp90 heterocomplexes localizes to cytoskeletal fibers extending from the perinuclear region to the plasma membrane and forming a rim under the plasma membrane of endothelial cells. p50, Mas70p (seven TPRs), which is a receptor for mitochondrial import, and the p60 (six to eight TPRs) component of the steroid receptor.hsp90 heterocomplex assembly system bind very tightly to hsp90 in a manner that is not competed by the CyP-40 fragment. However, bacterially expressed p60 blocks the binding of p50, Mas70p, FKBP52/hsp56, and CyP-40 to purified hsp90. The data are consistent with binding of all of these proteins to a site on hsp90 that is a general TPR domain acceptor. Our localization and binding data are used to develop a model in which proteins that are chaperoned by hsp90 move as dynamic complexes to their cellular sites of action, with the TPR-containing protein participating in targeting the movement of the complexes.

easyLINKAGE-Plus--automated linkage analyses using large-scale SNP data

We extended the original easyLINKAGE program by enabling linkage analyses for large-scale SNP data in addition to those of microsatellites. We implemented new modules for Allegro, Merlin, SimWalk, GeneHunter Imprinting, GeneHunter TwoLocus, SuperLink and extended FastSLink by automatic loop breaking and new outputs. We added conditional linkage analyses as well as multipoint simulation studies, and extended error test routines by checking for Mendelian/non-Mendelian genotyping errors and for deviations from Hardy-Weinberg equilibrium. Data can be analyzed in sets of markers, in defined centimorgan intervals and by using different allele frequency algorithms. The outputs consist of genome-wide as well as chromosomal postscript plots of LOD scores, NPL scores, P-values and other parameters.

AVAILABILITY

http://www.uni-wuerzburg.de/nephrologie/molecular_genetics/molecular_genetics.htm

CONTACT

tom.lindner@mail.uni-wuerzburg.de

SUPPLEMENTARY INFORMATION

Supplementary information is available on the website. The current version is v4.01beta.

[The annual cycle in the Djungarian Hamster Phodopus sungorus Pallas]

Seasonal variations in several functions were observed in a strain of Phodopus s. sungorus bred and kept in the laboratory at Erling-Andechs (47° 58'N, 11° 11'E) under natural illumination: 1. During their first winter most hamsters changed into a whitish winter coat (Figs. 2, 5, and 14). The change in fur coloration is described (Fig. 1). In most animals molt into the winter coat started in October or November, and was completed in December. Molt into the summer coat started in January or February, and was completed in March or early April. Hamsters kept at outdoor temperatures started molt into winter pelt earlier, and finished molt into summer pelt later, than animals kept indoors (Figs. 3 and 4). Winter coloration was more extreme in animals kept at outdoor temperatures. 2. Molt into the winter coat was induced in summer by exposing hamsters to short photoperiods (Fig. 6). However, these animals spontaneously changed back into summer fur while remaining under short-day conditions. 3. The animals had a marked annual cycle in body weight with maximum weight in July and August, and minimum weight in December and January, while they were in winter pelage (Figs. 7 and 8). 4. Reproduction was observed only between February and November (Fig. 9). Young were born within 18 days (2 cases) or 19 days (27 cases) after the breeding pairs were established. Mean litter size was 5 (range 1-9) (Fig. 10). Average litter size was smaller in the first litter of a ♀ than in the second, but was smaller again in subsequent litters (Fig. 11). 5. Growth curves of young hamsters were compared with data from the literature (Fig. 12). In the mean ♂ ♂ were heavier than ♀ ♀ (Table 1). 6. The majority of ♂ ♂ showed testis involution during the first winter. The weight of winter testes was about 1/9th that of summer testes (Fig. 13). The cauda epididymidis contained no spermatozoa in winter animals, and many in summer animals. 7. Daily torpor was observed in many animals, but only during the winter, and only in those animals that had changed into winter coloration. Body temperature dropped to about 20°C in hamsters kept at 6°C ambient temperature. 8. More than 10% of the animals remained in summer colour during the first winter (Figs. 2, 3, and 14). In these animals, testicular state and body weight corresponded to those of summer animals (Fig. 15), and torpor was not observed. 9. During their second winter, only a small percentage of animals changed into the winter coat, and even in these animals winter coloration was poorly expressed (Fig. 2). Testicular regression was also rare in the second winter, and less marked than in first-year animals (Fig. 16). The two individual testes in an animal often differed considerably in size and activity.-Reproduction almost ceased after the hamsters had lived through their second winter. 10. Phodopus has a midventral sebaceous gland, which is much larger in ♂ ♂ than in ♀ ♀. An annual cycle in its activity was indicated, but was not studied quantitatively. A discussion of the observations is presented which includes aspects of the situation in free-living populations.-The annual cycles of all the individual functions observed in the laboratory (body weight, testis activity, reproduction, colour change, torpidity) were strictly synchronized with each other, which suggests that these functions are regulated by a single complex of coupled factors, or even by one single factor, within the organism. The annual cycle was influenced by photoperiod, but it was not exclusively caused by external factors and their changes; an internal component of the annual cycle has to be potulated.

The cyclosporin A-binding immunophilin CyP-40 and the FK506-binding immunophilin hsp56 bind to a common site on hsp90 and exist in independent cytosolic heterocomplexes with the untransformed glucocorticoid receptor

We have recently shown that hsp56, the FK506-binding immunophilin component of both the heat shock protein (hsp90.hsp70.hsp56) heterocomplex and the untransformed glucocorticoid receptor heterocomplex, is bound directly to hsp90 (Czar, M. J., Owens-Grillo, J. K., Dittmar, K. D., Hutchison, K. A., Zacharek, A. M., Leach, K. L., Deibel, M. R., and Pratt, W. B. (1994) J. Biol. Chem. 269, 11155-11161). In this work, we show that both untransformed glucocorticoid receptor and hsp90 heterocomplexes contain CyP-40, a 40-kDa immunophilin of the cyclosporin A-binding class. CyP-40 is present in both native glucocorticoid receptor heterocomplexes and receptor heterocomplexes reconstituted with rabbit reticulocyte lysate, and the presence of CyP-40 in the receptor heterocomplex is stabilized by molybdate. Immunoadsorption of hsp90 from cell lysate yields coimmunoadsorption of both hsp56 and CyP-40, showing that both immunophilins are in native heterocomplex with hsp90. However, immunoadsorption of hsp56 does not yield coimmunoadsorption of CyP-40; thus, the two immunophilins do not exist in the same heterocomplex with hsp90. Both purified CyP-40 and hsp56 bind directly to purified hsp90, and excess CyP-40 blocks the binding of hsp56, consistent with the presence of a common immunophilin binding site on hsp90. Our data also suggest that there are at least two types of untransformed glucocorticoid receptor-hsp90 heterocomplexes, one that contains hsp56 and another that contains CyP-40. The role played by the immunophilins in steroid receptor action is unknown, but it is clear that the peptidylprolyl isomerase activity of immunophilins is not required for glucocorticoid receptor-hsp90 heterocomplex assembly and proper folding of the hormone binding domain by the hsp90-associated protein folding system of reticulocyte lysate.

Long-term weight change and breast cancer risk: the European prospective investigation into cancer and nutrition (EPIC)

We examined prospectively the association between weight change during adulthood and breast cancer risk, using data on 1358 incident cases that developed during 5.8 years of follow-up among 40 429 premenopausal and 57 923 postmenopausal women from six European countries, taking part in the European prospective investigation into cancer and nutrition study. Multivariate Cox regression models were used to calculate hazard ratios according to weight change (kg), defined as the weight difference between age at enrolment and age 20 adjusted for other risk factors. Changes in weight were not associated with premenopausal breast cancer risk. In postmenopausal women, weight gain was positively associated with breast cancer risk only among noncurrent hormone replacement therapy (HRT) users (P-trend ⩽0.0002). Compared to women with a stable weight (±2 kg), the relative risk for women who gained 15–20 kg was 1.50 (95% confidence interval (CI) 1.06–2.13). The pooled RR per weight gain increment of 5 kg was 1.08 (95% CI 1.04–1.12). Weight gain was not associated with breast cancer risk in current HRT users, although, overall, these women experienced a much higher risk of breast cancer compared with nonusers. Our findings suggest that large adult weight gain was a significant predictor of breast cancer in postmenopausal women not taking exogenous hormones.

Adjustment of pineal melatonin and N-acetyltransferase rhythms to change from long to short photoperiod in the Djungarian hamster Phodopus sungorus

In the Djungarian hamster Phodopus sungorus, the daily temporal pattern of synthesis and release of pineal hormone melatonin, mainly the length of the period of elevated melatonin levels, may be involved in transferring the information on day length to the neuroendocrine-gonadal axis. The present study investigated the time course of adjustment of the rhythm in melatonin production and concentration to the change from long to short photoperiods. Adult female Djungarian hamsters, maintained on a regime of 16 h of light and 8 h of darkness per day (LD 16:8) were transferred to the LD regime 8:16 and the daily rhythms in the pineal melatonin concentration and in the pineal N-acetyltransferase activity, as an indicator of melatonin formation, were studied at various intervals following the transfer. Under LD 16:8, the nocturnal melatonin concentration was elevated for 4.8 h. After 3 days on LD 8:16, no extension of the period of high melatonin levels occurred. 2, 4 and 6 weeks after the transfer to LD 8:16, the period of elevated melatonin levels lasted for 8.1, 9.3 and 11.5 h, respectively. Extension of the melatonin pattern proceeded first predominantly into the morning hours. Only after this extension was completed, a considerable extension into the evening hours began. Extension of the N-acetyltransferase rhythm on short photoperiods proceeded in the same way as that of the melatonin rhythm. The data show that while a change in the photoperiod might be seen by hamsters within 2 weeks after the transfer to LD 8:16, the full shortening of the photoperiod might be recognized only within 6 weeks or later.(ABSTRACT TRUNCATED AT 250 WORDS)

Disruption of the 11-cis-retinol dehydrogenase gene leads to accumulation of cis-retinols and cis-retinyl esters

To elucidate the possible role of 11-cis-retinol dehydrogenase in the visual cycle and/or 9-cis-retinoic acid biosynthesis, we generated mice carrying a targeted disruption of the 11-cis-retinol dehydrogenase gene. Homozygous 11-cis-retinol dehydrogenase mutants developed normally, including their retinas. There was no appreciable loss of photoreceptors. Recently, mutations in the 11-cis-retinol dehydrogenase gene in humans have been associated with fundus albipunctatus. In 11-cis-retinol dehydrogenase knockout mice, the appearance of the fundus was normal and punctata typical of this human hereditary ocular disease were not present. A second typical symptom associated with this disease is delayed dark adaptation. Homozygous 11-cis-retinol dehydrogenase mutants showed normal rod and cone responses. 11-cis-Retinol dehydrogenase knockout mice were capable of dark adaptation. At bleaching levels under which patients suffering from fundus albipunctatus could be detected unequivocally, 11-cis-retinol dehydrogenase knockout animals displayed normal dark adaptation kinetics. However, at high bleaching levels, delayed dark adaptation in 11-cis-retinol dehydrogenase knockout mice was noticed. Reduced 11-cis-retinol oxidation capacity resulted in 11-cis-retinol/13-cis-retinol and 11-cis-retinyl/13-cis-retinyl ester accumulation. Compared with wild-type mice, a large increase in the 11-cis-retinyl ester concentration was noticed in 11-cis-retinol dehydrogenase knockout mice. In the murine retinal pigment epithelium, there has to be an additional mechanism for the biosynthesis of 11-cis-retinal which partially compensates for the loss of the 11-cis-retinol dehydrogenase activity. 11-cis-Retinyl ester formation is an important part of this adaptation process. Functional consequences of the loss of 11-cis-retinol dehydrogenase activity illustrate important differences in the compensation mechanisms between mice and humans. We furthermore demonstrate that upon 11-cis-retinol accumulation, the 13-cis-retinol concentration also increases. This retinoid is inapplicable to the visual processes, and we therefore speculate that it could be an important catabolic metabolite and its biosynthesis could be part of a process involved in regulating 11-cis-retinol concentrations within the retinal pigment epithelium of 11-cis-retinol dehydrogenase knockout mice.

Femtosecond X-ray-induced explosion of C60 at extreme intensity

Understanding molecular femtosecond dynamics under intense X-ray exposure is critical to progress in biomolecular imaging and matter under extreme conditions. Imaging viruses and proteins at an atomic spatial scale and on the time scale of atomic motion requires rigorous, quantitative understanding of dynamical effects of intense X-ray exposure. Here we present an experimental and theoretical study of C60 molecules interacting with intense X-ray pulses from a free-electron laser, revealing the influence of processes not previously reported. Our work illustrates the successful use of classical mechanics to describe all moving particles in C60, an approach that scales well to larger systems, for example, biomolecules. Comparisons of the model with experimental data on C60 ion fragmentation show excellent agreement under a variety of laser conditions. The results indicate that this modelling is applicable for X-ray interactions with any extended system, even at higher X-ray dose rates expected with future light sources.

Systematic review and meta-analysis of the effect of portal triad clamping on outcome after hepatic resection

BACKGROUND

The effect of portal triad clamping (PTC) on outcome after hepatic resection is uncertain.

METHODS

A systematic literature search was conducted to detect randomized controlled trials (RCTs) assessing the effectiveness and safety of PTC alone and of PTC with ischaemic preconditioning (IPC) of the liver. Studies on clamping of the inferior vena cava or hepatic veins were excluded. Endpoints included postoperative overall morbidity and mortality, cardiopulmonary and hepatic morbidity, blood loss, transfusion rates and alanine aminotransferase (ALT) levels. Meta-analyses were performed using a random-effects model.

RESULTS

Eight RCTs published between 1997 and 2006 containing a total of 558 patients were eligible for final analysis. The design of the identified studies varied considerably. Analyses of endpoints revealed no difference between intermittent PTC and no PTC. Meta-analyses of PTC with and without previous IPC revealed no differences, but postoperative ALT levels were significantly lower with IPC.

CONCLUSION

On currently available evidence, the routine use of PTC does not offer any benefit in perioperative outcome after liver resection. It cannot be recommended as a standard procedure.