Comparative cytogenetics and heterochromatic patterns in two species of the genus Acanthostracion (Ostraciidae: Tetraodontiformes)

Some groups of fish, such as those belonging to the Order Tetraodontiformes, may differ significantly in the amount and location of heterochromatin in the chromosomes. There is a marked variation in DNA content of more than seven-fold among the families of this Order. However, the karyoevolutionary mechanisms responsible for this variation are essentially unknown. The largest genomic contents are present in species of the family Ostraciidae (2.20–2.60 pg). The present study cytogenetically characterized two species of the family Ostraciidae, Acanthostracion polygonius and A. quadricornis, using conventional staining, C-bandings, Ag-NOR, CMA₃/DAPI, AluI, PstI, EcoRI, TaqI and HinfI restriction enzymes (REs) and double FISH with 18S and 5S rDNA probes. The karyotypes of both species showed 2n = 52 acrocentric chromosomes (FN = 52; chromosome arms) and pronounced conserved structural characteristics. A significant heterochromatic content was observed equilocally distributed in pericentromeric position in all the chromosome pairs. This condition is unusual in relation to the karyotypes of other families of Tetraodontiformes and probability is the cause of the higher DNA content in Ostraciidae. Given the role played by repetitive sequences in the genomic reorganization of this Order, it is suggested that the conspicuous heterochromatic blocks, present in the same chromosomal position and with apparently similar composition, may have arisen or undergo evolutionary changes in concert providing clues about the chromosomal mechanisms which led to extensive variation in genomic content of different Tetraodontiformes families.     

Costs associated with low birth weight in a rural area of Southern Mozambique

Background

Low Birth Weight (LBW) is prevalent in low-income countries. Even though the economic evaluation of interventions to reduce this burden is essential to guide health policies, data on costs associated with LBW are scarce. This study aims to estimate the costs to the health system and to the household and the Disability Adjusted Life Years (DALYs) arising from infant deaths associated with LBW in Southern Mozambique.

Methods and Findings

Costs incurred by the households were collected through exit surveys. Health system costs were gathered from data obtained onsite and from published information. DALYs due to death of LBW babies were based on local estimates of prevalence of LBW (12%), very low birth weight (VLBW) (1%) and of case fatality rates compared to non-LBW weight babies [for LBW (12%) and VLBW (80%)]. Costs associated with LBW excess morbidity were calculated on the incremental number of hospital admissions in LBW babies compared to non-LBW weight babies. Direct and indirect household costs for routine health care were 24.12 US$ (CI 95% 21.51; 26.26). An increase in birth weight of 100 grams would lead to a 53% decrease in these costs. Direct and indirect household costs for hospital admissions were 8.50 US$ (CI 95% 6.33; 10.72). Of the 3,322 live births that occurred in one year in the study area, health system costs associated to LBW (routine health care and excess morbidity) and DALYs were 169,957.61 US$ (CI 95% 144,900.00; 195,500.00) and 2,746.06, respectively.

Conclusions

This first cost evaluation of LBW in a low-income country shows that reducing the prevalence of LBW would translate into important cost savings to the health system and the household. These results are of relevance for similar settings and should serve to promote interventions aimed at improving maternal care.     

Multidimensional analysis and detection of informative features in human brain white matter

The white matter contains long-range connections between different brain regions and the organization of these connections holds important implications for brain function in health and disease. Tractometry uses diffusion-weighted magnetic resonance imaging (dMRI) to quantify tissue properties along the trajectories of these connections. Statistical inference from tractometry usually either averages these quantities along the length of each fiber bundle or computes regression models separately for each point along every one of the bundles. These approaches are limited in their sensitivity, in the former case, or in their statistical power, in the latter. We developed a method based on the sparse group lasso (SGL) that takes into account tissue properties along all of the bundles and selects informative features by enforcing both global and bundle-level sparsity. We demonstrate the performance of the method in two settings: i) in a classification setting, patients with amyotrophic lateral sclerosis (ALS) are accurately distinguished from matched controls. Furthermore, SGL identifies the corticospinal tract as important for this classification, correctly finding the parts of the white matter known to be affected by the disease. ii) In a regression setting, SGL accurately predicts “brain age.” In this case, the weights are distributed throughout the white matter indicating that many different regions of the white matter change over the lifespan. Thus, SGL leverages the multivariate relationships between diffusion properties in multiple bundles to make accurate phenotypic predictions while simultaneously discovering the most relevant features of the white matter.     

Nitric oxide and superoxide dismutase modulate endothelial progenitor cell function in type 2 diabetes mellitus

Background

The renin-angiotensin aldosterone system (RAAS) plays an important role in regulating the blood pressure and the genetic polymorphisms of RAAS genes has been extensively studied in relation to the cardiovascular diseases in various populations with conflicting results. The aim of this study was to determine the association of five genetic polymorphisms (A6G and A20C of angiotensinogen (AGT), MboI of renin, Gly460Trp of aldosterone synthase and Lys173Arg of adducin) of RAAS genes in Malaysian essential hypertensive and type 2 diabetic subjects.

Methods

RAAS gene polymorphisms were determined using mutagenically separated PCR and PCR-RFLP method in a total of 270 subjects consisting of 70 hypertensive subjects without type 2 diabetes mellitus (T2DM), 60 T2DM, 65 hypertensive subjects with T2DM and 75 control subjects.

Results

There was significant difference found in age, body mass index, systolic/diastolic blood pressure, fasting plasma glucose and high density lipoprotein cholesterol levels between the hypertensive subjects with or without T2DM and control subjects. No statistically significant differences between groups were found in the allele frequency and genotype distribution for A20C variant of AGT gene, MboI of renin, Gly460Trp of aldosterone and Lys173Arg of adducin (p > 0.05). However, the results for A6G of AGT gene revealed significant differences in allele and genotype frequencies in essential hypertension with or without T2DM (p < 0.001).

Conclusion

Among the five polymorphisms of RAAS genes only A6G variant of AGT gene was significantly associated in Malaysian essential hypertensive and type 2 diabetic subjects. Therefore, A6G polymorphism of the AGT gene could be a potential genetic marker for increased susceptibility to essential hypertension with or without T2DMin Malaysian subjects.     

Alterations in carbohydrate metabolism in response to short-term dietary carbohydrate restriction

Dietary carbohydrate restriction (CR) presents a challenge to glucose homeostasis. Despite the popularity of CR diets, little is known regarding the metabolic effects of CR. The purpose of this study was to examine changes in whole body carbohydrate oxidation, glucose availability, endogenous glucose production, and peripheral glucose uptake after dietary CR, without the confounding influence of a negative energy balance. Postabsorptive rates of glucose appearance in plasma (R(a); i.e., endogenous glucose production) and disappearance from plasma (R(d); i.e., glucose uptake) were measured using isotope dilution methods after a conventional diet [60% carbohydrate (CHO), 30% fat, and 10% protein; kcals = 1.3 x resting energy expenditure (REE)] and after 2 days and 7 days of CR (5% CHO, 60% fat, and 35% protein; kcals = 1.3 x REE) in eight subjects (means +/- SE; 29 +/- 4 yr; BMI 24 +/- 1 kg/m(2)) during a 9-day hospital visit. Postabsorptive plasma glucose concentration was reduced (P = 0.01) after 2 days but returned to prediet levels the next day and remained at euglycemic levels throughout the diet (5.1 +/- 0.2, 4.3 +/- 0.3, and 4.8 +/- 0.4 mmol/l for prediet, 2 days and 7 days, respectively). Glucose R(a) and glucose R(d) were reduced to below prediet levels (9.8 +/- 0.6 micromol x kg(-1) x min(-1)) after 2 days of CR (7.9 +/- 0.3 micromol x kg(-1) x min(-1)) and remained suppressed after 7 days (8.3 +/- 0.4 micromol x kg(-1) x min(-1); both P < 0.001). A greater suppression in carbohydrate oxidation, compared with the reduction in glucose R(d), led to an increased (all P 相似文献   

Interleukin-7 administration alters intestinal intraepithelial lymphocyte phenotype and function in vivo

BACKGROUND: Interleukin-7 (IL-7) plays a crucial role in controlling T-cell development and homeostasis. IL-7 knock out and IL-7 receptor knock out mice show distinct declines in absolute numbers of the intestinal intraepithelial lymphocytes (IEL). Therefore, we hypothesized that exogenous administration of IL-7 would alter IEL phenotype and function. METHODS: Adult C57BL/6J mice were treated with IL-7 or saline. Mice were euthanized at day 7. Cytokine and keratinocyte growth factor (KGF) expressions were measured with RT-PCR. IEL phenotype was studied with flow cytometry. Finally, to address the association of endogenous epithelial cell (EC)-derived IL-7 and IEL, confocal microscopy was used to observe co-localization of IL-7 to IEL subpopulations. RESULTS: IL-7 administration significantly increased IEL numbers. CD8alphabeta+ IEL increased 3.2-fold, CD8+CD44+ IEL increased 1.3-fold, and alphabeta-T-cell receptor (TCR)+ IEL increased 1.3-fold. IL-7 administration also significantly changed both alphabeta-TCR+ IEL- and gammadelta-TCR+ IEL-derived cytokine expressions. Interestingly, IL-7 administration also led to a significant increase in KGF expression. Confocal microscopy showed a high level of co-localization between the alphabeta-TCR+ IEL and EC-derived IL-7. gammadelta-TCR+ IEL showed a lower level, but still significant, co-localization. CONCLUSION: IL-7 administration significantly affected IEL phenotype and function. The observed co-localization suggests that there is a close IEL-EC cross-communication mediated by EC-derived IL-7 expression.