Continuous flow method in soil microbiology

The continuous flow method, applied to the study of microbiological processes in soil samples, was used to study the biological immobilization of mineral forms of nitrogen and phosphorus. By means of this method, physical-chemical adsorption of mineral elements was differentiated from biological immobilization over a given period. Biological immobilization of nitrogen and phosphorus was related to the metabolic activity of the soil microflora. It was found that the amount of biological immobilization of nitrogen and phosphorus was closely associated with glucose decomposition. A correlation was found between the immobilization of nitrate nitrogen and carbon dioxide evolution during glucose decomposition and the amount of glucose utilized. The ratio of the amount of glucose carbon assimilated by the soil microflora to the amount of nitrogen immobilized depended on the C∶N ratio in the added solution.     

Guaianolides from two subspecies of Amphoricarpos neumayeri from Montenegro

Quantitative (1)H NMR measurements revealed delta(11(13)) sesquiterpene gamma-lactones as the main constituents ( >or= 1% per weight of dried plant material) in the crude extracts of the aerial parts of Amphoricarpos neumayeri ssp. neumayeri and ssp. murbeckii from mountains Orjen and Visitor (Montenegro), respectively. Preparative silica gel chromatography afforded thirteen guai-11(13)-en-12,6alpha-olides, named amphoricarpolides (1-13), with the same relative (1alphaH,4betaH,5alphaH,7betaH) configuration of the basic skeleton. The common structural feature of lactones 2-13 was 3beta,15-dioxygenation pattern. The only exception was 1 (3-deoxyamphoricarpolide), containing a single oxygen substituent (15-OH). Eight of them exhibited an additional oxygen substituent, 9beta-OH (5 and 6), 2alpha-OH (8-12), or 2alpha-OAc (13). Compound 7 was epoxydated at 10alpha(14)-position, whereas the remaining lactones contained a 10(14) double bond.     

Association of 25-Hydroxyvitamin D status and genetic variation in the vitamin D metabolic pathway with FEV1 in the Framingham Heart Study

Background

Vitamin D is associated with lung function in cross-sectional studies, and vitamin D inadequacy is hypothesized to play a role in the pathogenesis of chronic obstructive pulmonary disease. Further data are needed to clarify the relation between vitamin D status, genetic variation in vitamin D metabolic genes, and cross-sectional and longitudinal changes in lung function in healthy adults.

Methods

We estimated the association between serum 25-hydroxyvitamin D [25(OH)D] and cross-sectional forced expiratory volume in the first second (FEV₁) in Framingham Heart Study (FHS) Offspring and Third Generation participants and the association between serum 25(OH)D and longitudinal change in FEV₁ in Third Generation participants using linear mixed-effects models. Using a gene-based approach, we investigated the association between 241 SNPs in 6 select vitamin D metabolic genes in relation to longitudinal change in FEV₁ in Offspring participants and pursued replication of these findings in a meta-analyzed set of 4 independent cohorts.

Results

We found a positive cross-sectional association between 25(OH)D and FEV₁ in FHS Offspring and Third Generation participants (P = 0.004). There was little or no association between 25(OH)D and longitudinal change in FEV₁ in Third Generation participants (P = 0.97). In Offspring participants, the CYP2R1 gene, hypothesized to influence usual serum 25(OH)D status, was associated with longitudinal change in FEV₁ (gene-based P < 0.05). The most significantly associated SNP from CYP2R1 had a consistent direction of association with FEV₁ in the meta-analyzed set of replication cohorts, but the association did not reach statistical significance thresholds (P = 0.09).

Conclusions

Serum 25(OH)D status was associated with cross-sectional FEV₁, but not longitudinal change in FEV₁. The inconsistent associations may be driven by differences in the groups studied. CYP2R1 demonstrated a gene-based association with longitudinal change in FEV₁ and is a promising candidate gene for further studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0238-y) contains supplementary material, which is available to authorized users.     

Hydrophobic and adhesive capacity of Candida strains isolated from patients with fungal infection

The aim of this study was to evaluate hydrophobicity of fungal strains of Candida sp. isolated from clinical materials of patients with fungal infections. Two hundred and eighty one strains of C. albicans and 29 strains belonging to the other species of Candida were tested in salt aggregation test (SAT). Strong hydrophobicity (autoaggregation in the test) was found in 29.4% of tested strains. The majority of them was isolated from vagina. In 20 randomly selected strains hydrophobicity was measured not only by salt aggregation test but also by hydrophobic interaction chromatography (MIC). The ability to attach to buccal epithelial cells in vitro was compared between 50 strongly hydrophobic strains and 30 with low hydrophobicity. The former strains attached significantly stronger (p less than 0.001).