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1.
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.   相似文献   
2.
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.   相似文献   
3.
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.  相似文献   
4.

Background

Gulf War exposures in 1990 and 1991 have caused 25% to 30% of deployed personnel to develop a syndrome of chronic fatigue, pain, hyperalgesia, cognitive and affective dysfunction.

Methods

Gulf War veterans (n = 31) and sedentary veteran and civilian controls (n = 20) completed fMRI scans for diffusion tensor imaging. A combination of dolorimetry, subjective reports of pain and fatigue were correlated to white matter diffusivity properties to identify tracts associated with symptom constructs.

Results

Gulf War Illness subjects had significantly correlated fatigue, pain, hyperalgesia, and increased axial diffusivity in the right inferior fronto-occipital fasciculus. ROC generated thresholds and subsequent binary regression analysis predicted CMI classification based upon axial diffusivity in the right inferior fronto-occipital fasciculus. These correlates were absent for controls in dichotomous regression analysis.

Conclusion

The right inferior fronto-occipital fasciculus may be a potential biomarker for Gulf War Illness. This tract links cortical regions involved in fatigue, pain, emotional and reward processing, and the right ventral attention network in cognition. The axonal neuropathological mechanism(s) explaining increased axial diffusivity may account for the most prominent symptoms of Gulf War Illness.  相似文献   
5.
There is strong evidence that vasodilatory nitric oxide (NO) donors have anabolic effects on bone in humans. Parathyroid hormone (PTH), the only osteoanabolic drug currently approved, is also a vasodilator. We investigated whether the NO synthase inhibitor L‐NAME might alter the effect of PTH on bone by blocking its vasodilatory effect. BALB/c mice received 28 daily injections of PTH[1–34] (80 µg/kg/day) or L‐NAME (30 mg/kg/day), alone or in combination. Hindlimb blood perfusion was measured by laser Doppler imaging. Bone architecture, turnover and mechanical properties in the femur were analysed respectively by micro‐CT, histomorphometry and three‐point bending. PTH increased hindlimb blood flow by >30% within 10 min of injection (P < 0.001). Co‐treatment with L‐NAME blocked the action of PTH on blood flow, whereas L‐NAME alone had no effect. PTH treatment increased femoral cortical bone volume and formation rate by 20% and 110%, respectively (P < 0.001). PTH had no effect on trabecular bone volume in the femoral metaphysis although trabecular thickness and number were increased and decreased by 25%, respectively. Co‐treatment with L‐NAME restricted the PTH‐stimulated increase in cortical bone formation but had no clear‐cut effects in trabecular bone. Co‐treatment with L‐NAME did not affect the mechanical strength in femurs induced by iPTH. These results suggest that NO‐mediated vasorelaxation plays partly a role in the anabolic action of PTH on cortical bone. © 2016 The Authors. Cell Biochemistry and Function published by John Wiley & Sons, Ltd.  相似文献   
6.
One can determine the best dilution of a primary antibody for immunohistochemistry that uses horseradish peroxidase conjugated to a secondary antibody by testing increasing concentrations sequentially on the same tissue section. When the same tissue section is incubated repeatedly with increasing concentrations of primary antibodies to epithelial membrane antigen, smooth muscle α-actin, or vimentin using alkaline phosphatase conjugated to a secondary antibody as the reporter, the best staining was obtained with a less concentrated primary antibody than was optimal for a single staining test. The best concentration of primary antibody for single run staining using an alkaline phosphatase reporting system is usually four times the best concentration for staining with multiple runs. The optimal concentration can be determined by denaturing the residual alkaline phosphatase and extracting residual stain by incubating the section in 4:1 diglyme:phosphate buffered saline for 20 min at 80o C between tests of primary antibody concentrations. I tested the method for four chromogens from one supplier and one chromogen from a different supplier.  相似文献   
7.
Increased environmental pollution and unhealthy lifestyle are blamed for escalated chronic diseases. Exposure to aflatoxins was recently suggested to have a role in the increased incidence of type 2 diabetes mellitus. Diet modification and consumption of different functional food are now gaining attention, especially in diabetes management. This study investigates the effect of a diet containing barley microgreen against diabetes induced by streptozotocin with or without aflatoxin administration in rats. Barley microgreen was rich in 3′-Benzyloxy-5,6,7,4′-tetramethoxyflavone (48.8% of total) followed by 5β,7βH,10α-Eudesm-11-en-1α-ol (18.46%). Streptozotocin injection and/or aflatoxin administration significantly elevated glucose level, decreased insulin level, decreased β-cell function, deteriorated liver and kidney function parameters, and induced oxidative stress in the liver. Histopathology revealed irregular small-sized islets and decreased area % of insulin-positive beta cells in the pancreas, hepatic degeneration, nephropathy, and neuropathy in diabetic and/or aflatoxin administered rats compared to control. Barley microgreen diet fed to diabetic rats with or without aflatoxin alleviated all evaluated parameters. Barley microgreen diet also ameliorated the toxic effect of aflatoxin. In conclusion, exposure to aflatoxin aggravated diabetes and its complication. The incorporation of barley microgreen in the diet was able to control type 2 diabetes mellitus and the improved outcomes observed with barley microgreen treatments involved or occurred in conjunction with improved biomarkers of oxidative stress.  相似文献   
8.
The recent outbreak of Ebola Virus Disease (EVD) in West Africa has ravaged many lives. Effective containment of this outbreak relies on prompt and effective coordination and communication across various interventions; early detection and response being critical to successful control. The use of information and communications technology (ICT) in active surveillance has proved to be effective but its use in Ebola outbreak response has been limited. Due to the need for timeliness in reporting and communication for early discovery of new EVD cases and promptness in response; it became imperative to empower the response team members with technologies and solutions which would enable smooth and rapid data flow. The Open Data Kit and Form Hub technology were used in combination with the Dashboard technology and ArcGIS mapping for follow up of contacts, identification of cases, case investigation and management and also for strategic planning during the response. A remarkable improvement was recorded in the reporting of daily follow-up of contacts after the deployment of the integrated real time technology. The turnaround time between identification of symptomatic contacts and evacuation to the isolation facility and also for receipt of laboratory results was reduced and informed decisions could be taken by all concerned. Accountability in contact tracing was ensured by the use of a GPS enabled device. The use of innovative technologies in the response of the EVD outbreak in Nigeria contributed significantly to the prompt control of the outbreak and containment of the disease by providing a valuable platform for early warning and guiding early actions.  相似文献   
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