Ionoregulatory and oxidative stress issues associated with the evolution of air-breathing

Aquatic areas frequently face hypoxic conditions. In order to get sufficient oxygen to support aerobic metabolism, a number of freshwater fish resort to aerial respiration to supplement gill respiration especially in situations with reduced oxygen availability in the water. In many species a concomitant reduction in gill surface area or in gill perfusion reduces possible loss of aerially acquired oxygen to the water at the gills, but it also compromises the ion regulatory capacity of gill tissue. In consequence, the reduced gill contact area with water requires appropriate compensation to maintain ion and acid-base homeostasis, often with important ramifications for other organs. Associated modifications in the structure and function of the gills themselves, the skin, the gut, the kidney, and the physiology of water exchange and ion-linked acid-base regulation are discussed. In air-breathing fish, the gut may gain particular importance for the uptake of ions. In addition, tissues frequently exposed to environmental air encounter much higher oxygen partial pressures than typically observed in fish tissues. Physostomous fish using the swimbladder for aerial respiration, for example, will encounter aerial oxygen partial pressure at the swimbladder epithelium when frequently gulping air in hypoxic water. Hyperoxic conditions or rapid changes in oxygen partial pressures result in an increase in the production of reactive oxygen species (ROS). Accordingly, in air-breathing fish, strategies of ionoregulation may be greatly modified, and the ROS defense capacity of air-exposed tissues is improved.     

Correlation Analyses Reveal a Substantial Influence of Allelic Gaps on the Investigation of Genetic Diversity of Modern Human Populations with Microsatellites

High intra-population genetic diversity and multiple measures of genetic variability at STR loci are useful in inferring past evolutionary history. However, STRs, categorized by their repeat motif size, differ in a number of aspects, requiring separate analyses. We analyzed 783 STRs in 36 worldwide populations to examine marker suitability as well as correlations between various measurements, to evaluate the extent of genomic diversity present in modern human populations. The loci were grouped by type and analyzed separately for each population group. Genetic variation defined by gene diversity and allele size variance, shows different trends of variation across four types of STRs. Additionally, there is little variation of genetic diversity, but there is decreased allelic size variance with increasing repeat motifs. A poor correlation between genetic diversity and allelic size variance across loci in all groups for Di-STRs is probably caused by the presence of allelic size gaps. In contrast, allelic size variance, genetic diversity, and number of alleles are strongly correlated with both tri- and tetra-STRs. The positive correlation of allelic size variance and presence of gaps within the range of allelic sizes in Di-STRs alone explains these observations. An unexpected high imbalance index (β) at Di-STRs due to high allelic size variance also supports this assertion.     

Role of chromosomal imbalances in the pathogenesis of DSD: A retrospective analysis of 115 prenatal samples

Differences of sex development (DSDs) are a group of congenital conditions characterized by a discrepancy between chromosomal, gonadal, and genital sex development of an individual, with significant impact on medical, psychological and reproductive life. The genetic heterogeneity of DSDs complicates the diagnosis and almost half of the patients remains undiagnosed. In this context, chromosomal imbalances in syndromic DSD patients may help to identify new genes implicated in DSDs. In this study, we aimed at describing the burden of chromosomal imbalances including submicroscopic ones (copy number variants or CNVs) in a cohort of prenatal syndromic DSD patients, and review their role in DSDs. Our patients carried at least one pathogenic or likely pathogenic chromosomal imbalance/CNV or low-level mosaicism for aneuploidy. Almost half of the cases resulted from an unbalanced chromosomal rearrangement. Chromosome 9p/q, 4p/q, 3q and 11q anomalies were more frequently observed. Review of the literature confirmed the causative role of CNVs in DSDs, either in disruption of known DSD-causing genes (SOX9, NR0B1, NR5A1, AR, ATRX, …) or as a tool to suspect new genes in DSDs (HOXD cluster, ADCY2, EMX2, CAMK1D, …). Recurrent CNVs of regulatory elements without coding sequence content (i.e. duplications/deletions upstream of SOX3 or SOX9) confirm detection of CNVs as a mean to explore our non-coding genome. Thus, CNV detection remains a powerful tool to explore undiagnosed DSDs, either through routine techniques or through emerging technologies such as long-read whole genome sequencing or optical genome mapping.     

Risk factors for repeat abortion and implications for addressing unintended pregnancy in Vietnam

Objective

To determine predictors of repeat abortion in 3 provinces in Vietnam.

Methods

In a cross-sectional study between August and December 2011, women who underwent abortion were interviewed after the procedure in 62 public health facilities in Hanoi, Khanh Hoa, and Ho Chi Minh City (HCMC). Information on sociodemographic factors, contraceptive and reproductive history and intentions, and opinions and experience of abortion services was collected. The primary outcome was repeat (≥ 2) abortions.

Results

Overall, 1224 women were interviewed: 534 from Hanoi, 163 from Khanh Hoa, and 527 from HCMC. The mean age and parity of the respondents were 29 years and 1.8, respectively, and 79.6% were married. Approximately half of the respondents were not using contraception before pregnancy. The prevalence of repeat abortion was 31.7%. In multivariate models, significant predictors of repeat abortion included living in Hanoi, higher parity, age 35 years or older, and having 2 or more daughters (versus 1) or no sons (versus 1) after controlling for parity (all P < 0.05).

Conclusion

Repeat abortion remains high in Vietnam, fueled partly by inadequate contraceptive use. Son preference seems to be an important predictor of repeat abortion. Strengthening post-abortion contraceptive counseling and promoting long-acting contraceptive methods are essential to reduce repeat abortion.     

Percutaneous umbilical blood sampling

In the present day, fetal blood is sampled from the umbilical vein via a needle guided by dynamic ultrasound from the maternal abdomen (percutaneous umbilical blood sampling, PUBS). PUBS has become important in the fields of fetal physiology, diagnosis and therapy. Indications for PUBS are fetal karyotyping, prenatal diagnosis of blood disorders and congenital infection, and evaluation of fetal hypoxemia. Although risk of fetal loss following PUBS depends on the indication for the procedure and the experience of the operator, the rate of fetal loss after PUBS is assumed to be around 1%. Recent advances in molecular and cytogenetic techniques have restricted the number of reasons for using PUBS. However, since this technique offers a considerable advantage in enabling access directly to the fetal circulation, PUBS is likely to be used more frequently for fetal therapy than for prenatal diagnosis in the future.     

前列腺癌等位基因失衡(英文)

目的 了解前列腺癌克隆演变(clonal evolution)过程中遗传学机制. 方法 采用激光显微切割技术从保存的石蜡包埋组织中获取基因组DNA;利用6个位于染色体8p12-21、8p22、17q21上的具有多态性的微卫星标记,对25例患者原发癌及相应转移灶中等位基因的缺失或保留进行分析. 结果 在24例可供信息的病例中,14例(58%)在原发癌及相应转移灶中所有位点均表现为相同的等位基因缺失或保留模式,而另外10例(42%)则显示不一致的等位基因缺失.这10例中有5例原发癌表现为等位基因保留而在相应转移灶则为缺失,另外5例在一个或一个以上的位点表现为原发癌等位基因缺失而在相应转移灶保留. 结论 前列腺癌在原发癌及相应转移灶遗传组成上的差异可能与其内在异质性、整体遗传不稳定性及克隆差异有关.     

Alcohol intoxication in hospitalized young teenagers

The scientific literature concerning alcohol intoxication is enormous. However, less is known of alcohol-induced disturbances in children and adolescents and most of those reports concern cases of hypoglycemia in children under five years of age. We studied the clinical status and chemistry, especially acid-base balance, in 36 young teenagers treated at hospital for alcohol intoxication. On physical examination 6 patients were somnolent, 18 were comatose and 12 were in deep coma. The impairment of consciousness was directly proportional to the blood ethanol concentration. Acidosis was a central finding, and it was caused by a combination of respiratory and metabolic factors (a high blood PCO₂ and a low base excess; r = 0.97, p< 0.001); the finding of respiratory acidosis dominated. Base excess correlated negatively with beta-hydroxybutyrate and lactate, as expected. All the metabolic products measured—acetate, beta-hydroxybutyrate and lactate—were significantly elevated compared with the control patients. No hypoglycemia was found. Prior treatment with intravenous glucose decreased vomiting and normalized the serum lactate concentration and PO₂. Hypokalemia was the most common abnormality in serum electrolytes. In four patients the rate of fall of blood ethanol concentration was 2.8–3.3 mmol/h (0.13–0.15 g/l^-1 h^-1) and the mean acetate concentration was 0.8 mmol/l (SE 0.3). Biochemical disturbances in young teenage alcohol intoxicants resemble those previously found in adults. The severe toxicity by ethanol, planifesting in coma, occurs in lower blood alcohol concentrations in children than in adults     

严重烧伤后不同时段酸碱失衡类型变化的探讨

目的 :探讨严重烧伤病人在伤后不同时段 (伤后 1～ 3天、 4～ 1 0天、 >1 0天 )发生酸碱失衡类型的变化 ,分析其发生的原因及机理。方法 :利用新的酸碱失衡四步判断法对我科 1 990年 1月至 2 0 0 1年 1 2月住院的 1 5 3例严重烧伤病人同步检测的血气分析和电解质结果进行分析判断。结果 :(1 )全组患者除 1 6例酸碱失衡类型属正常外 ,其余 1 37例中 ,单纯性酸碱失衡类型 4 4例 ,其中以呼吸性碱中毒 (呼碱 )最多 ,2 3例 ;双重性 5 7例 ,以呼吸性碱中毒并代谢性酸中毒 (代酸 )为主 ,2 3例 ;三重性 36例 ,以呼吸性碱中毒并高阴离子间隙 (AG)代酸并代谢性碱中毒 (代碱 )为主 ,共 2 3例。 (2 )在休克期 (伤后 1～ 3天 )以单纯性酸碱失衡类型为主 ,最多见的类型是代谢性酸中毒 (1 4例 ) ,在水肿回收期 (伤后 4～ 1 0天 )与修复期 (伤后 1 0天以后 )均以双重性酸碱失衡类型为主 ,但最多见的类型分别是呼碱 (9例 )与呼碱并代碱 (5例 )。结论 :严重烧伤患者在伤后不同时段的酸碱失衡类型比较复杂 ,烧伤休克期的酸碱失衡类型最多 ,修复期最少。发生率最多的是呼碱、呼碱并代酸以及呼碱并高阴离子间隙代酸并代碱。在各时段中 ,三重性酸碱失衡并不少见 ,以呼碱并高AG代酸并代碱为主。