Transmembrane helices before, during, and after insertion

The transmembrane (TM) helix is the fundamental structural unit of helix-bundle membrane proteins. Recent biophysical studies provide new insights into the interactions of TM helices with each other and with membrane lipid bilayers. The biological process of helix insertion is carried out by translocon complexes acting in concert with ribosomes. An electron cryo-microscopic reconstruction of these complexes reveals their architecture in new detail, and shows that the complex is constructed from four SecY/Sec61 heterotrimers and two TRAP complexes. A disulfide bridge study shows that elongating polypeptide chains pass through the pore previously identified in the X-ray structure of an archaeal SecY heterotrimer. The fundamental code used by the translocon to select polypeptide segments for insertion as TM helices has been broken. A detailed analysis of the TM amino acid distributions of helix-bundle membrane proteins of known structure recapitulates this code.     

Carbohydrate nutrition before, during, and after exercise

The role of dietary carbohydrates (CHO) in the resynthesis of muscle and liver glycogen after prolonged, exhaustive exercise has been clearly demonstrated. The mechanisms responsible for optimal glycogen storage are linked to the activation of glycogen synthetase by depletion of glycogen and the subsequent intake of CHO. Although diets rich in CHO may increase the muscle glycogen stores and enhance endurance exercise performance when consumed in the days before the activity, they also increase the rate of CHO oxidation and the use of muscle glycogen. When consumed in the last hour before exercise, the insulin stimulated-uptake of glucose from blood often results in hypoglycemia, greater dependence on muscle glycogen, and an earlier onset of exhaustion than when no CHO is fed. Ingesting CHO during exercise appears to be of minimal value to performance except in events lasting 2 h or longer. The form of CHO (i.e., glucose, fructose, sucrose) ingested may produce different blood glucose and insulin responses, but the rate of muscle glycogen resynthesis is about the same regardless of the structure.     

Emotions before, during, and after dreaming sleep.

The aim of this study was to provide a preliminary overview of the emotions before, during, and after dreaming sleep in Chinese people. One hundred Chinese participants were included in the study. Cheerful emotions, including interest, exhilaration, and enjoyment, were pervasive in the collected dreams, although anxiety was also a common type of emotion. Positive correlations were found between the intensities of dream, presleep, and postsleep emotions. Significant reductions in intensity were noted in the analyses of emotions preceding dreaming sleep versus emotions following dreaming sleep. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Metabolism before,during and after anaesthesia in colic and healthy horses

Background  

Many colic horses are compromised due to the disease state and from hours of starvation and sometimes long trailer rides. This could influence their muscle energy reserves and affect the horses' ability to recover. The principal aim was to follow metabolic parameter before, during, and up to 7 days after anaesthesia in healthy horses and in horses undergoing abdominal surgery due to colic.     

Detection and prevention of protein aggregation before,during, and after purification

The use of proteins for in vitro studies or as therapeutic agents is frequently hampered by protein aggregation during expression, purification, storage, or transfer into requisite assay buffers. A large number of potential protein stabilizers are available, but determining which are appropriate can take days or weeks. We developed a solubility assay to determine the best cosolvent for a given protein that requires very little protein and only a few hours to complete. This technique separates native protein from soluble and insoluble aggregates by filtration and detects both forms of protein by SDS-PAGE or Western blotting. Multiple buffers can be simultaneously screened to determine conditions that enhance protein solubility. The behavior of a single protein in mixtures and crude lysates can be analyzed with this technique, allowing testing prior to and throughout protein purification. Aggregated proteins can also be assayed for conditions that will stabilize native protein, which can then be used to improve subsequent purifications. This solubility assay was tested using both prokaryotic and eukaryotic proteins that range in size from 17 to 150 kDa and include monomeric and multimeric proteins. From the results presented, this technique can be applied to a variety of proteins.     

Power performance of soccer referees before, during, and after official matches

The study aimed at verifying the effect of soccer refereeing on power performances, evaluated by means of countermovement (CMJ) and bounce (BJ) jumps. Ten soccer referees (age 23 +/- 3 years; V(.-)O2max 51.8 +/- 3.2 ml x kg(-1) x min(-1)) participated in this study. The physical load of refereeing was evaluated by means of subject's heart rate (HR), motor activities recorded during the match, and blood lactate measured at the end of the 2 halves. Analysis of variance and chi-square tested the differences between halves (p < 0.05). During the first half, the occurrence of subject's HR >85%HRmax was 62 +/- 31%, and it significantly (p < 0.05) decreased to 45 +/- 24% during the second half. Referees spent 41 +/- 5% running, 44 +/- 6% walking, and 15 +/- 5% inactivity, with no significant differences between halves. Blood lactate was significantly different only between warm-up (2.0 +/- 0.4 mM) and first half (4.7 +/- 2.9 mM). No significant difference emerged for CMJ and BJ after the 2 halves, demonstrating that young referees with acceptable fitness levels are able to maintain their all-out capabilities during the whole match.     

Changes in cytokinin activities before,during and after floral initiation in Polianthes tuberosa

The contents of endogenous cytokinin in tuberose corms (Polianthes tuberosa) at vegetative, early floral initiation, and flower development stages were investigated. We also determined the influence of exogenous cytokinin treatment on the corm apex at three different growth stages in relation to floral initiation and development in tuberose. The exogenous cytokinin effectively induced floral initiation and development, especially at the early floral initiation and flower development stages. Endogenous cytokinins were higher in early floral initiation and development stages in comparison to the vegetative stage. During floral initiation stage, the zeatin and dihydrozeatin increased significantly, while the cytokinins, zeatin riboside, dihydrozeatin riboside, ⁶N-(δ²-isopentenyl) adenine, and ⁶N-(δ²-isopentenyl) adenine riboside at consistently low levels. The increase of cytokinin levels in tuberose corms during floral induction suggests a role for cytokinins in tuberose apex evocation. Moreover, these results indicate that cytokinins seem to promote the development of flower buds rather than inducing flowering in tuberose.     

Gender Differences in Mental Health Outcomes before,during, and after the Great Recession

We examined gender differences in mental health outcomes during and post-recession versus pre-recession. We utilized 2005-2006, 2008-2009, and 2010-2011 data from the Medical Expenditure Panel Survey. Females had lower odds of depression diagnoses during and post-recession and better mental health during the recession, but higher odds of anxiety diagnoses post-recession. Males had lower odds of depression diagnoses and better mental health during and post-recession and lower Kessler 6 scores post-recession. We conducted stratified analyses, which confirmed that the aforementioned findings were consistent across the four different regions of the U.S., by employment status, income and health care utilization. Importantly, we found that the higher odds of anxiety diagnoses among females after the recession were mainly prominent among specific subgroups of females: those who lived in the Northeast or the Midwest, the unemployed, and those with low household income. Gender differences in mental health in association with the economic recession highlight the importance of policymakers taking these differences into consideration when designing economic and social policies to address economic downturns. Future research should examine the reasons behind the decreased depression diagnoses among both genders, and whether they signify decreased mental healthcare utilization or increased social support and more time for exercise and leisure activities.     

Myocardial interstitial glucose and lactate before,during, and after cardioplegic heart arrest

The interstitial fluid of the human myocardium was monitored in 13 patients undergoing aortic valve and/or bypass surgery before, during, and after hypothermic potassium cardioplegia. The regulation of glucose and lactate was studied after sampling with microdialysis. The following questions were addressed. 1). Is the rate of transcapillary diffusion the limiting step for myocardial uptake of glucose before or after cardioplegia? 2). Does cold potassium cardioplegia induce a critical deprivation of glucose and/or accumulation of lactate in the myocardium? Before cardioplegia, interstitial glucose was approximately 50% of the plasma level (P < 0.001). Interstitial glucose decreased significantly immediately after induction of cardioplegia and remained low (1.25 +/- 0.25 mM) throughout cardioplegia. It was restored to precardioplegic levels 1 h after release of the aortic clamp. Interstitial glucose then decreased again at 25 and 35 h postoperatively to the levels observed during cardioplegia. Interstitial lactate decreased immediately after induction of cardioplegia but returned to basal level during the clamping period. At 25 and 35 h, interstitial lactate was significantly lower than before and during cardioplegia. Glucose transport over the capillary endothelium is considered rate limiting for its uptake in the working heart but not during cold potassium cardioplegia despite the glucose deprivation following perfusion of glucose-free cardioplegic solution. Lactate accumulated during cardioplegia but never reached exceedingly high interstitial levels. We conclude that microdialysis provides information that may be relevant for myocardial protection during open-heart surgery.     

Hematochemical parameters in calves before, during and after weaning to a regular diet

The Authors studied the changes of 17 blood parameters of calves before, during and after a traditional weaning. Concentrations of total protein, albumin, urea nitrogen, creatinine, glucose, cholesterol, triglycerides, alkaline phosphatase, total bilirubin and phosphorus were determined by an automated assay system; sodium, potassium and chloride by a flame photometer; calcium, magnesium, copper and zinc by an atomic absorption spectrophotometer. Observed changes can be referred to: 1) the change of the digestion (glucose); 2) the age of the subjects (alkaline phosphatase); 3) the increase of weight (creatinine); 4) the type of feeding (phosphorus, copper and zinc). Sodium, potassium, chloride, calcium and magnesium did not change during the weaning.     

Medicine through the artist's eyes: before, during, and after the Holocaust

Pre-Holocaust German art celebrates the doctor as a hero, triumphant over disease and poor hygiene. It emphasizes the ontological conception of disease and the ability of medicine to cure pathology or remove it. Some New Objectivity artists question this conceptualization by pushing it to the extreme of realistic representations. However, the clinical encounter has virtually disappeared from post-Holocaust art. Medicine is depicted in three main ways: as an ambiguous and alien Faustian craft; with a focus on holistic notions of healing, thus avoiding biomedicine altogether; or with a focus on the subjective experience of illness, thus ignoring the interaction between medicine and the diseased person.     

Phrenic motoneuron firing rates before, during, and after prolonged inspiratory resistive loading

Road, J. D., and A. M. Cairns. Phrenic motoneuronfiring rates before, during, and after prolonged inspiratory resistive loading. J. Appl. Physiol. 83(3):776-783, 1997.Phrenic motoneuron firing rates during briefinspiratory resistive loading (IRL) are high, and nearly all themotoneurons are recruited. Diaphragmatic fatigue has been difficult todemonstrate during IRL. Furthermore, evidence from studies in limbmuscles has shown variable motoneuron responses to prolongedhigh-intensity loads. We studied phrenic motoneuron firing ratesbefore, during, and after prolonged IRL in anesthetized rabbits. Of 117 phrenic axons, only 2 axons were not recruited; 41 axons were silentduring unloaded breathing but were recruited at higher loads. Silentaxons showed a more rapid increase in firing rate as the loadincreased. Phrenic motoneuron firing rates increased throughout theperiod of loading, whereas airway pressure swings did not. Afterprolonged IRL, higher motoneuron firing rates were needed during briefloads to produce the same airway pressure. No evidence of a decline inmotoneuron firing rates was seen at any point. We conclude that therespiratory muscles can be shown to demonstrate physiological responsesconsistent with fatigue during prolonged IRL, and activation rates arehigh and remain so throughout this prolonged loading.