Vitamin D is a major determinant of bone mineral density at school age

Background

Vitamin D insufficiency in children may have long-term skeletal consequences as vitamin D affects calcium absorption, bone mineralization and bone mass attainment.

Methodology/Principal Findings

This school-based study investigated vitamin D status and its association with vitamin D intake and bone health in 195 Finnish children and adolescents (age range 7–19 years). Clinical characteristics, physical activity and dietary vitamin D intake were evaluated. Blood and urine samples were collected for serum 25-hydroxyvitamin D (25-OHD) and other parameters of calcium homeostasis. Bone mineral density (BMD) and body composition were measured with dual-energy X-ray absorptiometry (DXA). Altogether 71% of the subjects were vitamin D insufficient (25-OHD <50 nmol/L). The median 25-OHD was 41 nmol/L for girls and 45 nmol/L for boys, and the respective median vitamin D intakes 9.1 µg/day and 10 µg/day. In regression analysis, after adjusting for relevant factors, 25-OHD concentration explained 5.6% of the variance in lumbar BMD; 25-OHD and exercise together explained 7.6% of the variance in total hip BMD and 17% of the variance in whole body BMD. S-25-OHD was an independent determinant of lumbar spine and whole body BMD and in magnitude surpassed the effects of physical activity.

Conclusions/Significance

Vitamin D insufficiency was common even when vitamin D intake exceeded the recommended daily intake. Vitamin D status was a key determinant of BMD. The findings suggest urgent need to increase vitamin D intake to optimize bone health in children.     

Association between the ABO blood group and the human intestinal microbiota composition

ABSTRACT: BACKGROUND: The mucus layer covering the human intestinal epithelium forms a dynamic surface for host-microbial interactions. In addition to the environmental factors affecting the intestinal equilibrium, such as diet, it is well established that the microbiota composition is individually driven, but the host factors determining the composition have remained unresolved. RESULTS: In this study, we show that ABO blood group is involved in differences in relative proportion and overall profiles of intestinal microbiota. Specifically, the microbiota from the individuals harbouring the B antigen (secretor B and AB) differed from the non-B antigen groups and also showed higher diversity of the Eubacterium rectale-Clostridium coccoides (EREC) and Clostridium leptum (CLEPT) -groups in comparison with other blood groups. CONCLUSIONS: Our novel finding indicates that the ABO blood group is one of the genetically determined host factors modulating the composition of the human intestinal microbiota, thus enabling new applications in the field of personalized nutrition and medicine.     

Detergency effects of nanofibrillar amyloid formation on glycation of human serum albumin

The prolonged glycation of human serum albumin (HSA) results in significant changes in its structure. The identity of these structural changes and the influence of carbohydrates on these changes require further study. Here, we evaluated structural changes and amyloid formation of HSA upon incubation with Glc, Fru, or Rib. Fluorescence spectrophotometry, surface tension analysis, and transmission electron microscopy (TEM) were utilized to evaluate the structures of glycated HSA. The physicochemical properties including excess free energy, protein adsorption at the air-water interface, critical aggregation concentration (CAC), and surface activity indicated an increase in hydrophobicity and partial unfolding of HSA structure upon glycation. Thus, it appears that AGE products can act as detergents. Incubation of HSA with these sugars after 20 wks induced significant amyloid nanofibril formation. Together these results indicate that prolonged glycation of HSA is associated with a transition from helical structure to beta-sheet (amyloid formation).     

Characterization of the interaction between Actinin-Associated LIM Protein (ALP) and the rod domain of α-actinin

Background  

The PDZ-LIM proteins are a family of signalling adaptors that interact with the actin cross-linking protein, α-actinin, via their PDZ domains or via internal regions between the PDZ and LIM domains. Three of the PDZ-LIM proteins have a conserved 26-residue ZM motif in the internal region, but the structure of the internal region is unknown.     

Structural basis of the zinc- and terbium-mediated inhibition of ferroxidase activity in Dps ferritin-like proteins

Streptococcus suis Dpr is an iron-binding protein involved in oxidative stress resistance. It belongs to the bacterial Dps protein family whose members form dodecameric assemblies. Previous studies have shown that zinc and terbium inhibit iron incorporation in Listeria innocua Dps protein. In order to gain structural insights into the inhibitory effect of zinc and terbium, the crystal structures of Streptococcus suis Dpr complexes with these ions were determined at 1.8 A and 2.1 A, respectively. Both ions were found to bind at the ferroxidase center and in the same location as iron. In addition, a novel zinc-binding site formed by His40 and His44 was identified. Both His residues were found to be present within all known Streptococcus suis Dpr variants and in Streptococcus pneumoniae, Streptococcus gordonii, and Streptococcus sanguinis Dpr proteins. Amino acid sequence alignment of Dpr with other Dps family members revealed that His44 is highly conserved, in contrast to His40. The inhibitory effect of zinc and terbium on iron oxidation in Dpr was studied in vitro, and it was found that both ions at concentrations >0.2 mM almost completely abolish iron binding. These results provide a structural basis for the inhibitory effect of zinc and terbium in the Dps family of proteins, and suggest a potential role of the Dps proteins in zinc detoxification mechanisms involving the second zinc-binding site.     

Effect of flooding and draw‐down disturbance on germination from a seashore meadow seed bank

Abstract. The objective of this study was to investigate the effects of flooding and draw‐down on the germination from the coastal grassland seed banks and to determine whether the effect of flooding varies between the delta and the seashore. Seed bank samples were collected from three shore transects in SW Finland, two on the shore of the Baltic Sea and one on the delta of River Kokemäenjoki. Samples were germinated in non‐flooded and flooded conditions for over a month, after which both treatments were maintained in non‐flooded conditions. A total of 9267 seedlings of 47 species germinated and mean density of seeds in the soil was ca. 84 000/m². Most of the seedlings were monocots (98%) and perennials (98%). Ca. 30–40% of the species found in the above‐ground vegetation had a seed bank including the majority of the most abundant species. The number of seeds and species richness increased as the organic layer became thicker. The organic layer was thicker in the seashore samples and the seed bank was significantly larger than in the delta. The flooding and draw‐down treatment significantly increased the number of germinating seedlings in the seashore and also increased species richness in two transects, one in the delta and the other in the seashore. Two species, Schoenoplectus tabernaemontani and Typha latifolia, had significantly higher germination in the flooded treatment than in the non‐flooded. Apparently, many species in these coastal grasslands have adapted to flood disturbance and for seeds of some species flooding may work as a positive signal, possibly breaking dormancy.     

新疆葡萄新害虫——绿长突叶蝉主要生物学特性

【目的】绿长突叶蝉是中国新纪录种,是危害新疆葡萄生产的新害虫,为明确其生物学特性,进行了调查研究。【方法】田间定点调查,悬挂粘虫板、糖醋液诱集,结合室内饲养观察等方法。【结果】室内饲养表明,若虫共5龄,各龄期的平均发育历期分别为3.88、6.31、5.16、5.28、7.00 d;雌、雄成虫平均寿命分别为9.5和6.4 d。田间观察表明,绿长突叶蝉以卵在寄主葡萄上越冬,在新疆玛纳斯一年发生3代,越冬代卵于4月底开始孵化,5月下旬越冬代开始孵化为成虫;第1代卵从6月中旬开始孵化,7月中旬若虫开始羽化;第2代从8月初开始,一直持续到10月底;成虫主要在夜晚21点至23点及凌晨6点至8点活动。【结论】绿长突叶蝉一年发生3代,以卵越冬;若虫共5龄,具有较强的趋嫩性;成虫有较强的趋黄性,一定的趋光性,趋蓝性较弱,对糖醋液无趋性。试验结果可为葡萄安全生产,防治绿长突叶蝉提供理论依据。     

A comparison of unheated loose housing with stables on the respiratory health of weaned-foals in cold winter conditions: an observational field-study

Background

Newly weaned horses in Finland are often moved to unheated loose housing systems in which the weanlings have free access to a paddock and a shelter. This practice is considered to be good for the development of young horses. The daily temperatures can stay below ? 20 °C in Finland for several consecutive weeks during the winter season. However, the effect of unheated housing in a cold climatic environment on the respiratory health of weanlings under field conditions has not been studied before. This investigation was an observational field-study comprising 60 weanlings among 11 different voluntary participant rearing farms in Finland. Weanlings were either kept in unheated loose housing systems (n = 36) or in stables (n = 24) and were clinically examined on two separate occasions 58 days apart in cold winter conditions.

Results

The odds of clinical respiratory disease were lower in the older foals (log_e days); OR = 0.009, P = 0.044). The plasma fibrinogen concentration was higher when the available space (m²/weanling) in the sleeping hall was smaller (P = 0.014) and it was lower when the sleeping hall was not insulated (P = 0.010). The plasma fibrinogen concentrations at the second examination were lower with a body condition score above 3 (P = 0.070). Standardbreds kept in loose housing systems had a lower body condition score than Finnhorses or Standardbreds kept in stables at both examinations (P = 0.026 and P = 0.007, respectively). Haemoglobin level was lower in weanlings in loose housing systems compared to their counterparts at the first examination (P = 0.037). Finnhorses had higher white blood cell count than Standardbreds at first (P = 0.002) and at the second examination (P = 0.001).

Conclusions

Keeping weanling horses in cold loose housing systems does not seem to increase the occurrence of respiratory disease, but special attention should be focused on ventilation, air quality and feeding-practices. Our field study data suggest it might be advantageous to keep Standardbred foals born late in the season in a stable over the Finnish winter.

     

Maturation at a young age and small size of European smelt (<Emphasis Type="Italic">Osmerus eperlanus</Emphasis>): A consequence of population overexploitation or climate change?

Age of fish at maturation depends on the species and environmental factors but, in general, investment in growth is prioritized until the first sexual maturity, after which a considerable and increasing proportion of resources are used for reproduction. The present study summarizes for the first the key elements of the maturation of European smelt (Osmerus eperlanus) young of the year (YoY) in the North-eastern Gulf of Riga (the Baltic Sea). Prior to the changes in climatic conditions and collapse of smelt fishery in the 1990s in the Gulf of Riga, smelt attained sexual maturity at the age of 3–4 years. We found a substantial share (22%) of YoY smelt with maturing gonads after the collapse of the smelt fisheries. Maturing individuals had a significantly higher weight, length and condition factor than immature YOY, indicating the importance of individual growth rates in the maturation process. The proportion of maturing YoY individuals increased with fish size. We discuss the factors behind prioritizing reproduction overgrowth in early life and its implications for the smelt population dynamics.