Study of the effect of lactose on the structure of sodium alginate films

The aim of this study was to evaluate the interaction between the film-forming sodium alginate and lactose monohydrate. This combination is used in the co-spray-drying technique for microencapsulation, but no respect on the structure of the film formed has not been published previously. From mechanical tests, positronium lifetime measurements and FT-IR studies on free films containing different ratios of film-former and lactose, we concluded that the mechanical strength of the sodium alginate film decreased with the increasing proportion of lactose. The free volume in the polymer matrix decreased to a minimum as the lactose content was progressively increased to 40%, but subsequently increased at higher lactose contents. The explanation of this phenomenon is the filling of the holes with the sugar. As lactose became predominant component, the structure of the polymer network weakened. These conclusions were supported by the FT-IR findings. The present results permit a clear explanation of the previously reported favourable effects of this film-forming combination on the dissolution of the active agent from the microcapsules.     

定向进化人α型干扰素基因家族的研究

应用DNA改组(DNAshuffling)技术重组了12种人α型干扰素基因,并结合噬菌体表面呈现(phagedisplay)技术构建了噬菌体干扰素改组文库,采用简便的、功能性的定向竞争筛选方法,获得了比活达1 0×109IU/mg的新型α型基因工程复合干扰素,是目前国际上已投产的α2型干扰素的5倍,具有生产应用前景,上述策略也为其它细胞因子或酶的改造提供了借鉴方法。     

Insulin resistance and decreased spexin in Indian Patients with Type 2 Diabetes Mellitus

Spexin is novel biomarker, which plays a potential role in glucose and lipid metabolisms. However, there was paucity of serum spexin levels in obesity and diabetes mellitus subjects. Hence the current study was aimed to find the relationship between the serum spexin levels in type 2 Diabetes mellitus (type 2 DM) with extrapolation of cardiovascular disease (CVD) risk. A cross-sectional study included 330 participants, subdivided as control (n=110), type 2 DM (n=110) and type 2 DM with CVD groups (n=110). HbA1c, insulin, lipid profile, spexin & leptin including blood pressure and body mass index were analyzed from all the participants. The serum spexin levels (ng/ml) were significantly decreased in type 2 DM (mean ± sd: 0.65 ± 0.03) and type 2 DM with CVD (0.48 ± 0.02) groups compared to the control (0.79 ± 0.03) group (p<0.001). The decreased spexin levels were observed in type 2 DM, and further more decreased in type 2 DM with CVD patients compared to controls indicating that spexin levels could be served as an early prediction of obesity-induced T2DM with CVD risk.     

Selection of haplotype variables from a high-density marker map for genomic prediction

Background

Using haplotype blocks as predictors rather than individual single nucleotide polymorphisms (SNPs) may improve genomic predictions, since haplotypes are in stronger linkage disequilibrium with the quantitative trait loci than are individual SNPs. It has also been hypothesized that an appropriate selection of a subset of haplotype blocks can result in similar or better predictive ability than when using the whole set of haplotype blocks. This study investigated genomic prediction using a set of haplotype blocks that contained the SNPs with large effects estimated from an individual SNP prediction model. We analyzed protein yield, fertility and mastitis of Nordic Holstein cattle, and used high-density markers (about 770k SNPs). To reach an optimum number of haplotype variables for genomic prediction, predictions were performed using subsets of haplotype blocks that contained a range of 1000 to 50 000 main SNPs.

Results

The use of haplotype blocks improved the prediction reliabilities, even when selection focused on only a group of haplotype blocks. In this case, the use of haplotype blocks that contained the 20 000 to 50 000 SNPs with the highest effect was sufficient to outperform the model that used all individual SNPs as predictors (up to 1.3 % improvement in prediction reliability for mastitis, compared to individual SNP approach), and the achieved reliabilities were similar to those using all haplotype blocks available in the genome data (from 0.6 % lower to 0.8 % higher reliability).

Conclusions

Haplotype blocks used as predictors can improve the reliability of genomic prediction compared to the individual SNP model. Furthermore, the use of a subset of haplotype blocks that contains the main SNP effects from genomic data could be a feasible approach to genomic prediction in dairy cattle, given an increase in density of genotype data available. The predictive ability of the models that use a subset of haplotype blocks was similar to that obtained using either all haplotype blocks or all individual SNPs, with the benefit of having a much lower computational demand.     

Implications of the age range in a population-based BRCA1 testing program with eligibility based on family history of breast and ovarian cancer

The current options available to BRCA1 mutation carriers can be classified as either cancer risk reduction or increased disease surveillance. Risk reduction might be preferable to young women. Increased surveillance might be more attractive to women when their cancer risk is highest. The aim of this report is to estimate the sensitivity, specificity and ability to detect carriers for a population-based BRCA1 testing program with eligibility based on family history of cancer, and examine the effect of age on the program's performance. A computer model was used to simulate the incidence of breast and ovarian cancer in a woman's family, based on her BRCA1 mutation carrier status. Age-specific estimates of the sensitivity and specificity for family history as an indicator of mutation status were applied to local population figures. Sensitivity of the program increased with the age of the proband and the size of her family. Sensitivity ranged from 0.33 for 20-year-olds with small families, to 0.98 for 60-year-olds with large families. Specificity was greater than 0.95, regardless of a woman's age or family size. If 0.12% of people carry a BRCA1 mutation, a province-wide testing program for people aged 20-69 with referrals based only on family history would have a sensitivity of 0.55. Only 2% of the genetic test results would be positive. The acceptability of a genetic testing program depends on its sensitivity and specificity, and on the options available to women who are found to carry a mutation. Compared with variation due to family size, the program sensitivity and specificity does not differ substantially amongst the various age groups.     

Genomic prediction of genetic merit using LD-based haplotypes in the Nordic Holstein population

Background

A haplotype approach to genomic prediction using high density data in dairy cattle as an alternative to single-marker methods is presented. With the assumption that haplotypes are in stronger linkage disequilibrium (LD) with quantitative trait loci (QTL) than single markers, this study focuses on the use of haplotype blocks (haploblocks) as explanatory variables for genomic prediction. Haploblocks were built based on the LD between markers, which allowed variable reduction. The haploblocks were then used to predict three economically important traits (milk protein, fertility and mastitis) in the Nordic Holstein population.

Results

The haploblock approach improved prediction accuracy compared with the commonly used individual single nucleotide polymorphism (SNP) approach. Furthermore, using an average LD threshold to define the haploblocks (LD≥0.45 between any two markers) increased the prediction accuracies for all three traits, although the improvement was most significant for milk protein (up to 3.1 % improvement in prediction accuracy, compared with the individual SNP approach). Hotelling’s t-tests were performed, confirming the improvement in prediction accuracy for milk protein. Because the phenotypic values were in the form of de-regressed proofs, the improved accuracy for milk protein may be due to higher reliability of the data for this trait compared with the reliability of the mastitis and fertility data. Comparisons between best linear unbiased prediction (BLUP) and Bayesian mixture models also indicated that the Bayesian model produced the most accurate predictions in every scenario for the milk protein trait, and in some scenarios for fertility.

Conclusions

The haploblock approach to genomic prediction is a promising method for genomic selection in animal breeding. Building haploblocks based on LD reduced the number of variables without the loss of information. This method may play an important role in the future genomic prediction involving while genome sequences.     

Metal enrichment in water and fish in a semi-urban Nigerian lake,and their associated risks

Trace metal (Zn, Pb, Cu, Cr and Cd) concentrations in the water column and in the liver, muscle and gill tissues of Parachanna obscura and Clarias gariepinus in Agulu Lake, Nigeria, were investigated in June 2014 and compared with WHO and FAO safe limits for water and fish. Hazard index (HI) values were estimated to assess the potential public health risk of consuming contaminated fish. Lead and cadmium exceeded WHO guideline values for drinking water. In most cases, variations in concentration of the metals in organs were liver > muscle > gill. Differences in tissue-specific concentrations between species were not significant, except for zinc in muscles and gills. Cadmium and chromium were not detected in the fish, but lead was above the FAO maximum value for consumption. Hazard index values were below 1, indicating a low risk to public health. However, trace metal contamination in Agulu Lake is increasing.     

Real-time imaging of the dynamics of secretory granules in growth cones

Secretory granules containing a hybrid protein consisting of the regulated secretory protein tissue plasminogen activator and an enhanced form of green fluorescent protein were tracked at high spatial resolution in growth cones of differentiated PC12 cells. Tracking shows that granules, unlike synaptic vesicles, generally are mobile in growth cones. Quantitative analysis of trajectories generated by granules revealed two dominant modes of motion: diffusive and directed. Diffusive motion was observed primarily in central and peripheral parts of growth cones, where most granules diffused two to four orders of magnitude more slowly than comparably sized spheres in dilute solution. Directed motion was observed primarily in proximal parts of growth cones, where a subset of granules underwent rapid, directed motion at average speeds comparable to those observed for granules in neurites. This high-resolution view of the dynamics of secretory granules in growth cones provides insight into granule organization and release at nerve terminals. In particular, the mobility of granules suggests that granules, unlike synaptic vesicles, are not tethered stably to cytoskeletal structures in nerve terminals. Moreover, the slow diffusive nature of this mobility suggests that secretory responses involving centrally distributed granules in growth cones will occur slowly, on a time scale of minutes or longer.