Big flies, small repeats: the "Thr-Gly" region of the period gene in Diptera

The region of the clock gene period (per) that encodes a repetitive tract of threonine-glycine (Thr-Gly) pairs has been compared between Dipteran species both within and outside the Drosophilidae. All the non- Drosophilidae sequences in this region are short and present a remarkably stable picture compared to the Drosophilidae, in which the region is much larger and extremely variable, both in size and composition. The accelerated evolution in the repetitive region of the Drosophilidae appears to be mainly due to an expansion of two ancestral repeats, one encoding a Thr-Gly dipeptide and the other a pentapeptide rich in serine, glycine, and asparagine or threonine. In some drosophilids the expansion involves a duplication of the pentapeptide sequence, but in Drosophila pseudoobscura both the dipeptide and the pentapeptide repeats are present in larger numbers. In the nondrosophilids, however, the pentapeptide sequence is represented by one copy and the dipeptide by two copies. These observations fulfill some of the predictions of recent theoretical models that have simulated the evolution of repetitive sequences.      

人类小腿肌肉对运动训练生理响应的电学特性研究

目的 运动训练已被证明能够改善许多慢性肌肉功能疾病,被用于治疗衰老型肌萎缩。本文采用电阻抗成像(electrical impedance tomography,EIT)研究人类小腿肌肉对运动训练生理响应的电学特性,旨在使用EIT方法可视化运动训练对人类小腿响应肌肉隔室内肌肉纤维体积增加的效果。方法 实验对象被要求在连续5个实验日进行左、右腿单侧提踵训练,应用EIT检测每日运动训练前和运动训练后小腿肌肉的电导率分布。为了定量分析运动训练对响应肌肉隔室的作用,使用配对样本t检验分析EIT重建图像的空间平均电导率<σ>。结果 运动训练后,由小腿腓肠肌组成的M₁肌肉隔室空间平均电导率<σ>_M1显著增加。此外,连续5个实验日的EIT测量结果显示,运动训练前的空间平均电导率<σ^pre>_M1呈上升趋势。所有实验对象在实验日1早晨进行实验前的腿部瘦体重与<σ>_M1呈线性关系,即<σ>_M1随腿部瘦体重增加而增加;运...     

Evolutionary origin of human and primate malarias: evidence from the circumsporozoite protein gene

We have analyzed the conserved regions of the gene coding for the circumsporozoite protein (CSP) in 12 species of Plasmodium, the malaria parasite. The closest evolutionary relative of P. falciparum, the agent of malignant human malaria, is P. reichenowi, a chimpanzee parasite. This is consistent with the hypothesis that P. falciparum is an ancient human parasite, associated with humans since the divergence of the hominids from their closest hominoid relatives. Three other human Plasmodium species are each genetically indistinguishable from species parasitic to nonhuman primates; that is, for the DNA sequences included in our analysis, the differences between species are not greater than the differences between strains of the human species. The human P. malariae is indistinguishable from P. brasilianum, and P. vivax is indistinguishable from P. simium; P. brasilianum and P. simium are parasitic to New World monkeys. The human P. vivax-like is indistinguishable from P. simiovale, a parasite of Old World macaques. We conjecture that P. malariae, P. vivax, and P. vivax-like are evolutionarily recent human parasites, the first two at least acquired only within the last several thousand years, and perhaps within the last few hundred years, after the expansion of human populations in South America following the European colonizations. We estimate the rate of evolution of the conserved regions of the CSP gene as 2.46 x 10(-9) per site per year. The divergence between the P. falciparum and P. reichenowi lineages is accordingly dated 8.9 Myr ago. The divergence between the three lineages leading to the human parasites is very ancient, about 100 Myr old between P. malariae and P. vivax (and P. vivax-like) and about 165 Myr old between P. falciparum and the other two.      

Excitation of System I and System II in Photosynthesis as a Possible Control Mechanism of Glycolate Metabolism in the Blue-Green Alga Anacystis nidulans

Photosynthetic enhancement studies performed at 619 nm (excitation of Systems I and II) and at 446 nm (mainly excitation of System I) revealed an 18% photosynthetic enhancement simultaneously with a 31% reduction in glycolate excretion. This observation supports the hypothesis that some glycolate may be consumed in an oxidation process associated with System I when System II is poorly excited and the supply of electrons from the water splitting process of photosynthesis is low.     

土壤中棉花黄萎病菌SYBR Green Ⅰ荧光RT-PCR定量检测技术研究

为实现田间土壤棉花黄萎病菌的早期检测,建立了土壤中棉花黄萎病菌的SYBR Green I荧光定量PCR检测方法。以含342bp PCR扩增产物的阳性质粒为参考,构建了标准曲线,并对该曲线的特异性、敏感性、可重复性进行了评价。结果表明,该方法具有快速、特异性强、敏感度高等特点。检测范围在3.8×103-3.8×108copies/μL之间有良好的线性关系,相关系数R2为0.996,扩增效率为101.5%,灵敏度比常规PCR方法高102倍。     

A Decreased Level of Serum Soluble Klotho Is an Independent Biomarker Associated with Arterial Stiffness in Patients with Chronic Kidney Disease

Background

Klotho was originally identified in a mutant mouse strain unable to express the gene that consequently showed shortened life spans. In humans, low serum Klotho levels are related to the prevalence of cardiovascular diseases in community-dwelling adults. However, it is unclear whether the serum Klotho levels are associated with signs of vascular dysfunction such as arterial stiffness, a major determinant of prognosis, in human subjects with chronic kidney disease (CKD).

Methods

We determined the levels of serum soluble Klotho in 114 patients with CKD using ELISA and investigated the relationship between the level of Klotho and markers of CKD-mineral and bone disorder (CKD-MBD) and various types of vascular dysfunction, including flow-mediated dilatation, a marker of endothelial dysfunction, ankle-brachial pulse wave velocity (baPWV), a marker of arterial stiffness, intima-media thickness (IMT), a marker of atherosclerosis, and the aortic calcification index (ACI), a marker of vascular calcification.

Results

The serum Klotho level significantly correlated with the 1,25-dihydroxyvitamin D level and inversely correlated with the parathyroid hormone level and the fractional excretion of phosphate. There were significant decreases in serum Klotho in patients with arterial stiffness defined as baPWV≥1400 cm/sec, atherosclerosis defined as maximum IMT≥1.1 mm and vascular calcification scores of ACI>0%. The serum Klotho level was a significant determinant of arterial stiffness, but not endothelial dysfunction, atherosclerosis or vascular calcification, in the multivariate analysis in either metabolic model, the CKD model or the CKD-MBD model. The adjusted odds ratio of serum Klotho for the baPWV was 0.60 (p = 0.0075).

Conclusions

Decreases in the serum soluble Klotho levels are independently associated with signs of vascular dysfunction such as arterial stiffness in patients with CKD. Further research exploring whether therapeutic approaches to maintain or elevate the Klotho level could improve arterial stiffness in CKD patients is warranted.     

Good Psychometric Properties of the Addiction Version of the Revised Illness Perception Questionnaire for Health Care Professionals

BackgroundAddiction, or substance dependence, is nowadays considered a chronic relapsing condition. However, perceptions of addiction vary widely, also among healthcare professionals. Perceptions of addiction are thought to contribute to attitude and stigma towards patients with addiction. However, studies into perceptions of addiction among healthcare professionals are limited and instruments for reliable assessment of their perceptions are lacking. The Illness Perception Questionnaire (IPQ) is widely used to evaluate perceptions of illness. The aim of this study was to evaluate the psychometric properties of the IPQ: factor structure, internal consistency, and discriminant validity, when applied to evaluate healthcare professionals’ perceptions of addiction.MethodsParticipants were 1072 healthcare professionals in training and master students from the Netherlands and Indonesia, recruited from various addiction-training programs. The revised version of the IPQ was adapted to measure perceptions of addiction (IPQ-A). Maximum likelihood method was used to explore the best-fit IPQ factor structure. Internal consistency was evaluated for the final factors. The final factor structure was used to assess discriminant validity of the IPQ, by comparing illness perceptions of addiction between 1) medical students from the Netherlands and Indonesia, 2) medical students psychology students and educational science students from the Netherlands, and 3) participants with different training levels: medical students versus medical doctors.ResultsFactor analysis revealed an eight-factor structure for the perception subscale (demoralization, timeline chronic, consequences, personal control, treatment control, illness coherence, timeline cyclical emotional representations) and a four-factor structure for the attribution subscale (psychological attributions, risk factors, smoking/alcohol, overwork). Internal reliability was acceptable to good. The IPQ-A was able to detect differences in perceptions between healthcare professionals from different cultural and educational background and level of training.ConclusionsThe IPQ-A is a valid and reliable instrument to assess healthcare professionals’ perceptions of addiction.     

Laparoscopic appendectomy to remove a metallic foreign body in a wild Bornean orangutan (Pongo pygmaeus) undergoing rehabilitation

A laparoscopic appendectomy was performed in a wild orangutan (Pongo pygmaeus) undergoing rehabilitation, for a metal nail found on radiographs, using 3‐mm instrumentation. Post‐operative healing was rapid and uneventful, with return to the forest within 10 days. This is the first report of minimally invasive surgery in a wild orangutan.