Effect of access to a running wheel on behavior of C57BL/6J mice.

BACKGROUND AND PURPOSE: To evaluate how and when mice run on a running wheel and how ad libitum access to the wheel affect behavior, feed intake, and weight gain. METHODS: Seventeen 2-month-old C57BL/6J mice had access to the wheel, whereas 19 control mice did not. After 3 to 6.5 weeks, behavior was video-recorded over 24 h for each mouse. RESULTS: Experimental mice ran an average 2 km/24 h in 114 min. Highest running activity took place at the onset of darkness. Experimental mice spent 22 min more feeding on the cage floor than did control mice. These times were deducted from those for all other behaviors: 74 min from resting time, 39 min from climbing and feeding on the cage lid, 14 min from locomotion on the cage floor, and 10 min from grooming. In relative figures, deduction from sleeping time was only 9%, whereas climbing time was halved. CONCLUSIONS: Climbing on the cage lid has a similar circadian rhythm as does wheel running and high-energy expenditure. Because experimental mice climbed less, their weight gain and feed intake were similar to those of control mice. Thus, wheel running can substitute for other forms of energy-consuming behaviors and vice versa.     

Application of selected cationic dyes for the semiquantitative estimation of glycosaminoglycans in histological sections of articular cartilage by microspectrophotometry

Summary Selected commonly used cationic dyes, viz. Thionin, Safranin O, Toluidine Blue O, Dimethylmethylene Blue, Cuprolinic Blue, Cupromeronic Blue,N, N-Diethylpseudoisocyanine, and a modified PAS-method, and staining method, with a variety of alternative procedures, e.g., variation of pH, use of the critical electrolyte concentration method, and blocking reactions (methylation-saponification, carboxymethylation), were tested to select optimal staining procedures for the semiquantitative histochemical estimation of glycosaminoglycans by microspectrophotometry in sections of articular cartilage. The methods were carried out on 3 m-thick paraffin and 1 m-thick glycolmethacrylate sections of bovine articular cartilage. The staining intensity of the sections was measured from spots 25 m apart using a leitz MPV 3 microspectrophotometer, starting at the surface of the cartilage and ending up at the tidemark. The result was compared with the fixed-charge density graph determined from the adjacent articular cartilage.Of the dyes tested, Thionin and Safranin O proved to be excellent cationic dyes for the histochemical quantification of cartilage matrix proteoglycans, since the staining intensity curves showed a linear correlation (r=0.900–0.995) with the fixed charge density curves from the adjacent cartilage. Also, the stain distribution was consistently uniform across the sections. In 1 m-thick glycolmethacrylate sections, the Safranin O staining gradient showed almost perfect identity with the fixed-charge density curve. Cuprolinic Blue and Cupromeronic Blue combined with the critical electrolyte concentration technique were also useful for the microspectrophotometric assays of glycosaminoglycans, but the presence of metachromasia should be checked prior to the measurements. The reliability of blocking procedures for quantitative histochemical work was not convincing.     

Evaluation of Bioremediation Treatments in a Shoreline-Simulating Microcosm

A microcosm test was designed to study the efficiency of bioremediation treatments at oil contaminated shorelines. The biodegradation in the hermetically closed microcosm was monitored by measuring the total cumulative inorganic carbon evolved during the bioremediation process. The effects of three different additives, medium-release methylene urea (MU) + apatite, fast-release MU + superphosphate, and a biosorbent, on the biodegradation of weathered crude oil (North Sea Brent) were evaluated at +10°C. All the additives significantly increased mineralization. The total amount of inorganic carbon evolved during the 10-week study was measured in the microcosm treated with oil, and with oil and medium-release MU + apatite, fast-release MU + superphosphate, and biosorbent. The amounts were 40,670,490, and 580 mg, respectively. The respirometric measurements were supported by microbiological determinations, ATP content in the sand, number of heterotrophic bacteria, and amount of biomass-C determined by the substrate-induced respiration method. Nutrient analysis indicated that biodegradation was nitrogen limited. The microcosm test proved to be suitable for comparing the effectiveness of different treatments in enhancing the biodegradation of crude oil-contaminated shores.     

Bone Health and Risk Factors of Cardiovascular Disease - A Cross-Sectional Study in Healthy Young Adults

Objective

Both osteoporosis and cardiovascular disease (CVD) are diseases that comprise a growing medical and economic burden in ageing populations. They share many risk factors, including ageing, low phy-sical activity, and possibly overweight. We aimed to study associations between individual risk factors for CVD and bone mineral density (BMD) and turnover markers (BTMs) in apparently healthy cohort.

Design

A cross-sectional assessment of 155 healthy 32-year-old adults (74 males) was performed for skeletal status, CVD risk factors and lifestyle factors.

Methods

We analysed serum osteocalcin, procollagen I aminoterminal propeptide (P1NP), collagen I carboxy-terminal telopeptide (ICTP) and urine collagen I aminoterminal telopeptide (U-NTX), as well as serum insulin, plasma glucose, triglyceride and HDL-cholesterol levels. BMD, fat and lean mass were asses-sed using DXA scanning. Associations were tested with partial correlations in crude and adjusted mo-dels. Bone status was compared between men with or without metabolic syndrome (defined according to the NCEP-ATPIII criteria) with multivariate analysis.

Results

Osteocalcin and P1NP correlated inversely with insulin (R = −0.243, P = 0.003 and R = −0.187, P = 0.021) and glucose (R = −0.213, P = 0.009 and R = −0.190, P = 0.019), but after controlling for fat mass and lifestyle factors, the associations attenuated with insulin (R = −0.162, P = 0.053 and R = −0.093, P = 0.266) and with glucose (R = −0.099, P = 0.240 and R = −0.133, P = 0.110), respectively. Whole body BMD associated in-versely only with triglycerides in fully adjusted model. In men with metabolic syndrome, whole body BMD, osteocalcin and P1NP were lower compared to healthy men, but these findings disappeared in fully adjusted model.

Conclusions

In young adults, inverse associations between BTM/BMD and risk factors of CVD appeared in crude models, but after adjusting for fat mass, no association continued to be present. In addition to fat mass, lifestyle factors, especially physical activity, modified the associations between CVD and bone charac-teristics. Prospective studies are needed to specify the role of mediators and lifestyle factors in the prevention of CVD and osteoporosis.     

Demographic history has influenced nucleotide diversity in European Pinus sylvestris populations

To infer the role of natural selection in shaping standing genetic diversity, it is necessary to assess the genomewide impact of demographic history on nucleotide diversity. In this study we analyzed sequence diversity of 16 nuclear loci in eight Pinus sylvestris populations. Populations were divided into four geographical groups on the basis of their current location and the geographical history of the region: northern Europe, central Europe, Spain, and Turkey. There were no among-group differences in the level of silent nucleotide diversity, which was approximately 0.005/bp in all groups. There was some evidence that linkage disequilibrium extended further in northern Europe than in central Europe: the estimates of the population recombination rate parameter, rho, were 0.0064 and 0.0294, respectively. The summary statistics of nucleotide diversity in central and northern European populations were compatible with an ancient bottleneck rather than the standard neutral model.     

Higher Free Fatty Acid Uptake in Visceral Than in Abdominal Subcutaneous Fat Tissue in Men

Visceral adipose tissue has been shown to have high lipolytic activity. The aim of this study was to examine whether free fatty acid (FFA) uptake into visceral adipose tissue is enhanced compared to abdominal subcutaneous tissue in vivo. Abdominal adipose tissue FFA uptake was measured using positron emission tomography (PET) and [¹⁸F]‐labeled 6‐thia‐hepta‐decanoic acid ([¹⁸F]FTHA) and fat masses using magnetic resonance imaging (MRI) in 18 healthy young adult males. We found that FFA uptake was 30% higher in visceral compared to subcutaneous adipose tissue (0.0025 ± 0.0018 vs. 0.0020 ± 0.0016 µmol/g/min, P = 0.005). Visceral and subcutaneous adipose tissue FFA uptakes were strongly associated with each other (P < 0.001). When tissue FFA uptake per gram of fat was multiplied by the total tissue mass, total FFA uptake was almost 1.5 times higher in abdominal subcutaneous than in visceral adipose tissue. In conclusion, we observed enhanced FFA uptake in visceral compared to abdominal subcutaneous adipose tissue and, simultaneously, these metabolic rates were strongly associated with each other. The higher total tissue FFA uptake in subcutaneous than in visceral adipose tissue indicates that although visceral fat is active in extracting FFA, its overall contribution to systemic metabolism is limited in healthy lean males. Our results indicate that subcutaneous, rather than visceral fat storage plays a more direct role in systemic FFA availability. The recognized relationship between abdominal visceral fat mass and metabolic complications may be explained by direct effects of visceral fat on the liver.