Are Elevated Aminotransferases and Decreased Bilirubin Additional Characteristics of the Metabolic Syndrome?

Abnormal liver tests, as well as morphological changes in the liver, are frequent among obese patients. Other frequent disturbances are visceral fat accumulation, insulin resistance, non-insulin-dependent diabetes mellitus (NIDDM), hypertriglyceridemia, and hypertension; these are a set of aberrations known as the metabolic syndrome. In order to investigate a possible relationship between the metabolic syndrome and impaired liver status we examined associations between liver tests, metabolic variables (insulin, glucose, and triglycerids), body composition and nutrition in 1083 men (BMI 28.8–63.8 kg/m²) and 1367 women (BMI 26.7–68.0 kg/m²) in the ongoing intervention study of Swedish Obese Subjects (SOS). Standard biochemical techniques were used to assess liver status and metabolic variables. Lean body mass (LBM) and masses of visceral and subcutaneous adipose tissue (AT) were estimated by means of computed tomography (CT) calibrated anthropometric equations. In both genders aspartate aminotransferase and alanine aminotransferase were, or tended to be, positively correlated to fasting serum insulin, visceral AT (women), and alcohol intake. In women, the aminotransferases were also correlated with fasting blood glucose. In both genders alkaline phosphatase was, or tended to be, positively associated with visceral AT, insulin (women), and glucose. Bilirubin was negatively correlated to insulin and visceral AT in men and women. Additional multivariate analyses indicated that alcohol had less explanatory power than serum insulin for the examined liver tests, especially among women. These results suggest that pathological liver tests in the obese may represent an expression of the metabolic syndrome.     

Rapid Nissl Staining for Frozen Sections of Fresh Brain

Working with X-ray film autoradiography of soluble isotopes, we needed a staining technique for the localization of nuclei in frozen sections of fresh brain. We have found no Nissl staining method in the literature concerning autoradiography specially recommended for this purpose, nor have we found in handbooks on staining a Nissl method clearly recommended for unfixed, frozen sections of brain. The methods described are intended for paraffin or celloidin sections, and require fixation of brain before sectioning (which must be avoided when working with soluble isotopes). Because autoradiography is a time-consuming method, any technique which shortens time needed for the overall procedure is welcome. Most Nissl techniques described in the literature require long preprocessing of the tissue. We found two rapid methods, described by Humason (1967) and LaBossiere and Glickstein (1976), but their application to frozen sections did not give good results. After trials with several types of techniques, we succeeded in developing two Nissl modifications with slightly different qualities, one of 12 min and the other of 2-3 h. The longer method includes conventional steps in staining; the shorter method does not include fixation or lipid extraction. These methods were applied to 20-60 μm brain sections cut in the cryostat at -10 to -12 C and dried on gelatinized slides.     

Long-Term Effect of Bariatric Surgery on Liver Enzymes in the Swedish Obese Subjects (SOS) Study

Background and Aim

Obesity is associated with elevated serum transaminase levels and non-alcoholic fatty liver disease and weight loss is a recommended therapeutic strategy. Bariatric surgery is effective in obtaining and maintaining weight loss. Aim of the present study was to examine the long-term effects of bariatric surgery on transaminase levels in obese individuals.

Methods

The Swedish Obese Subjects (SOS) study is a prospective controlled intervention study designed to compare the long-term effects of bariatric surgery and usual care in obese subjects. A total of 3,570 obese participants with no excess of alcohol consumption at baseline (1,795 and 1,775 in the control and surgery group, respectively) were included in the analyses. Changes in transaminase levels during follow-up were compared in the surgery and control groups.

Results

Compared to usual care, bariatric surgery was associated with lower serum ALT and AST levels at 2- and 10- year follow up. The reduction in ALT levels was proportional to the degree of weight loss. Both the incidence of and the remission from high transaminase levels were more favorable in the surgery group compared to the control group. Similarly, the prevalence of ALT/AST ratio <1 was lower in the surgery compared to the control group at both 2- and 10-year follow up.

Conclusions

Bariatric surgery results in a sustained reduction in transaminase levels and a long-term benefit in obese individuals.     

Postreplicative recruitment of cohesin to double-strand breaks is required for DNA repair

Chromosome stability depends on accurate chromosome segregation and efficient DNA double-strand break (DSB) repair. Sister chromatid cohesion, established during S phase by the protein complex cohesin, is central to both processes. In the absence of cohesion, chromosomes missegregate and G2-phase DSB repair fails. Here, we demonstrate that G2-phase repair also requires the presence of cohesin at the damage site. Cohesin components are shown to be recruited to extended chromosome regions surrounding DNA breaks induced during G2. We find that in the absence of functional cohesin-loading proteins (Scc2/Scc4), the accumulation of cohesin at DSBs is abolished and repair is defective, even though sister chromatids are connected by S phase generated cohesion. Evidence is also provided that DSB induction elicits establishment of sister chromatid cohesion in G2, implicating that damage-recruited cohesin facilitates DNA repair by tethering chromatids.     

Sex chromosome evolution and speciation in Ficedula flycatchers

Speciation is the combination of evolutionary processes that leads to the reproductive isolation of different populations. We investigate the significance of sex-chromosome evolution on the development of post- and prezygotic isolation in two naturally hybridizing Ficedula flycatcher species. Applying a tag-array-based mini-sequencing assay to genotype single nucleotide polymorphisms (SNPs) and interspecific substitutions, we demonstrate rather extensive hybridization and backcrossing in sympatry. However, gene flow across the partial postzygotic barrier (introgression) is almost exclusively restricted to autosomal loci, suggesting strong selection against introgression of sex-linked genes. In addition to this partial postzygotic barrier, character displacement of male plumage characteristics has previously been shown to reinforce prezygotic isolation in these birds. We show that male plumage traits involved in reinforcing prezygotic isolation are sex linked. These results suggest a major role of sex-chromosome evolution in mediating post- and prezygotic barriers to gene flow and point to a causal link in the development of the two forms of reproductive isolation.     

On-line high performance liquid chromatography measurements of extracellular metabolites in an aerobic batch yeast (<Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis>) culture

We constructed a bioprocess environment enabling automatic sampling from a bioreactor combined with a compact on-line high performance liquid chromatography (HPLC) unit. This setup allowed us to measure extracellular glucose, ethanol, glycerol, and acetate concentrations automatically at 5 min intervals during the cultivation. This environment also provides mechanical measurement of the optical density (OD) of cells and enables us to collect and store (−35°C) samples for further off-line analyses. Among the available devices, the performance of the sampling-analysis unit is by far the best with regard to speed and number of analytes. Both the sampling and analysis phases are easily controlled by software; thus, providing a unique environment to perform various bioprocess activity tasks, whether they would be cell line screening or optimisation of conditions for growth and productivity. Complex research set-ups can be created and continuous automated measurements empower long-term cultivations with a time series. We provide evidence for the applicability of this environment by performing three comparable batch cultivations with Saccharomyces cerevisiae yeast and show that both the on-line sampling and analysis modes produce reliable data for further use in the monitoring and controlling of bioprocesses. On-line data provided new insight into the dynamics of the diauxic shift during aerobic glucose batch cultivation. When cell growth and carbon dioxide production ceased for the first time during the diauxic shift, acetate accumulation and consumption of the remaining glucose below 0.15 g/L continued to occur for 1 h. At the same time, glycerol and ethanol began to be consumed. Samples were also collected during cultivation for later analysis of intracellular metabolites and to collect more valuable information about metabolism.     

Fine root foraging strategies in Norway spruce forests across a European climate gradient

Fine root acclimation to different environmental conditions is crucial for growth and sustainability of forest trees. Relatively small changes in fine root standing biomass (FRB), morphology or mycorrhizal symbiosis may result in a large change in forest carbon, nutrient and water cycles. We elucidated the changes in fine root traits and associated ectomycorrhizal (EcM) fungi in 12 Norway spruce stands across a climatic and N deposition gradient from subarctic‐boreal to temperate regions in Europe (68°N–48°N). We analysed the standing FRB and the ectomycorrhizal root tip biomass (EcMB, g m^?2) simultaneously with measurements of the EcM root morphological traits (e.g. mean root length, root tissue density (RTD), N% in EcM roots) and frequency of dominating EcM fungi in different stands in relation to climate, soil and site characteristics. Latitude and N deposition explained the greatest proportion of variation in fine root traits. EcMB per stand basal area (BA) increased exponentially with latitude: by about 12.7 kg m^?2 with an increase of 10° latitude from southern Germany to Estonia and southern Finland and by about 44.7 kg m^?2 with next latitudinal 10° from southern to northern Finland. Boreal Norway spruce forests had 4.5 to 11 times more EcM root tips per stand BA, and the tips were 2.1 times longer, with 1.5 times higher RTD and about 1/3 lower N concentration. There was 19% higher proportion of root tips colonized by long‐distance exploration type forming EcM fungi in the southern forests indicating importance of EcM symbiont foraging strategy in fine root nutrient acquisition. In the boreal zone, we predict ca. 50% decrease in EcMB per stand BA with an increase of 2 °C annual mean temperature. Different fine root foraging strategies in boreal and temperate forests highlight the importance of complex studies on respective regulatory mechanisms in changing climate.