Systematic analysis of ground reaction forces before and after hip and knee arthroplasty]

In this prospective study we employed a newly developed gait analysis system to compare the ground reaction force patterns in 15 patients before and after total hip or knee replacement. In this system, data are measured separately for each limb. Measured data were also obtained from 30 healthy adults and compared with those obtained from the patient group. We analysed the three-dimensional force patterns, impulse, frequency, stride and double stance, and compared changes in the postoperative gait patterns. The vertical force maxima Fy identify the peak forces obtaining during walking. The results showed significantly increased (p < 0.05) postoperative force maxima Fy2 and Fy3 for both knee replacement (Fy2: 82.48 to 86.17 and Fy3: 96.09 to 99.35% body weight, pre- and postoperatively, respectively) and hip replacement (Fy2: 84.44 to 88.08 and Fy3: 98.63 to 101.96% body weight, pre- and postoperatively, respectively). The ADAL system proved suitable for the easy performance of gait analysis, and thus may be of future value in the area of clinical quality assurance.     

Differentiation and frequency distributions of body weights in plants and animals

The basic and simplest system that one can consider in ecology is a group of individuals of equal age and representing one species, that is, a cohort. This paper is an attempt to show that analysis of such a system may be of great importance to understanding basic ecological problems, such as, intraspecific competition and the dynamics of a single population. It is easy to observe that in even-aged populations individuals differ in weights. A close look can show that weight distributions in even-aged populations may have different skewness. Most common are distributions with coefficients of skewness greater than zero. Sometimes weight distributions are symmetrical or with skewness coefficients less than zero. In a cohort of growing individuals the coefficient of skewness changes with time: most often starting from zero (symmetrical distribution), it increases in time; sometimes after an initial increase it can decrease in the final stage of growth, which is related to an increased mortality of individuals. The rate of change in skewness, and the skewness itself depend on the density of individuals in a cohort and on food conditions. They are greater at higher densities and increase with deteriorating food conditions. Weight distributions are symmetrical at low densities and optimal food conditions. The differences in individual weights measured by variance of weight distributions or coefficient of variation follow the same pattern, but observed changes with time, density and food conditions are not so clear. These conclusions rest upon the review of numerous papers concerning both plants and animals, which is presented in this paper. In the past, the properties of weight distributions in even-aged populations were explained not by interactions between individuals, but rather as a natural outcome of the growth process of non-interacting individuals. The exponential equation of growth, with relative growth rate having a normal distribution in populations, was used to support this hypothesis. Obtained weight distributions were of positive skewness; however, this model, which in fact is able to describe the growth process only in its initial stage, cannot explain the changes of skewness of weight distributions with density and food conditions. A model has been developed which includes competitive interactions among members of even-aged populations to explain observed properties of weight distributions in them. The basic assumption is that intraspecific competition leads to uneven partitioning of resources, which are the object of competition. Functions describing resource partitioning among individuals are included into the model.(ABSTRACT TRUNCATED AT 400 WORDS)     

A study of the single polypeptide nature of rhodanese. A comparison of different preparations.

The enzyme rhodanese (EC 2.8.1.1) appears as a single polypeptide chain protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular weight of this species is approx. 33 000. This contrasts with previous reports that rhodanese behaves on gel filtration chromatography as a rapidly equilibrating monomer-dimer system composed of identical subunits with a molecular weight of 18 500. We have investigated this apparent discrepancy by isolating the enzyme by the two different preparative procedures used in the above investigations. The two crystalline samples were subjected to gel filtration chromatography under a wide variety of conditions and to sodium dodecyl sulfate disc gel electrophoresis. The two preparations yielded rhodanese which behaved identically and no evidence for the monomeric species was obtained under any experimental condition tested. Thin-layer gel chromatography of clarified liver homogenates gave no evidence of rhodanese species other than that present in the purified samples. The variation in molecular weights observed in gel filtration chromatography may be a reflection of the conformational mobility of the enzyme leading to solvent-dependent changes in Stokes radius. If rhodanese is dimeric, special interactions must stabilize it under the conditions tested here.     

人体特征的头发代谢组学及蛋白质组学研究进展

人类头发是以角蛋白和角蛋白相关蛋白为主要成分的天然纤维,是一种可表征一定时间内机体状态的良好生物学样本。头发易采集、低成本、易于运输和存储等优点使其在毒品、酒精及兴奋剂等的检测中具有独特优势。蛋白质组学是一种在整体水平上研究蛋白表达和调控的新兴技术,在生命科学领域应用广泛。蛋白质组学技术可用于不同人群头发蛋白组成及动态变化研究,在寻找疾病标志物、区分个人特质等方面具有巨大潜力。本文从头发的结构及组成、心理压力下头发的变化以及头发蛋白质组学分析技术的研究进展进行了全面综述,对理解头发蛋白质组学表征人体特征以及指导相关研究具有重要意义。     

Usefulness of combining intermittent hypoxia and physical exercise in the treatment of obesity

Obesity is an important public health problem worldwide and is a major risk factor for a number of chronic diseases such as type II diabetes, adverse cardiovascular events and metabolic syndrome-related features. Different treatments have been applied to tackle body fat accumulation and its associated clinical manifestations. Often, relevant weight loss is achieved during the first 6 months under different dietary treatments. From this point, a plateau is reached, and a gradual recovery of the lost weight may occur. Therefore, new research approaches are being investigated to assure weight maintenance. Pioneering investigations have reported that oxygen variations in organic systems may produce changes in body composition. Possible applications of intermittent hypoxia to promote health and in various pathophysiological states have been reported. The hypoxic stimulus in addition to diet and exercise can be an interesting approach to lose weight, by inducing higher basal noradrenalin levels and other metabolic changes whose mechanisms are still unclear. Indeed, hypoxic situations increase the diameter of arterioles, produce peripheral vasodilatation and decrease arterial blood pressure. Furthermore, hypoxic training increases the activity of glycolytic enzymes, enhancing the number of mitochondria and glucose transporter GLUT-4 levels as well as improving insulin sensitivity. Moreover, hypoxia increases blood serotonin and decreases leptin levels while appetite is suppressed. These observations allow consideration of the hypothesis that intermittent hypoxia induces fat loss and may ameliorate cardiovascular health, which might be of interest for the treatment of obesity. This new strategy may be useful and practical for clinical applications in obese patients.     

Molecular weight of human high-molecular-weight kininogen light chain by equilibrium sedimentation in an air-driven ultracentrifuge

High-molecular-weight kininogen, a nonenzymatic glycoprotein of the intrinsic blood coagulation system, is proteolytically cleaved by kallikrein as an early event in the activation of this system. The light chain of cleaved kininogen retains the ability to form specific noncovalent complexes with prekallikrein and factor XI, other members of this system. We have determined the molecular weight of human kininogen light chain by equilibrium sedimentation in buffers of differing density, using an air-driven benchtop ultracentrifuge. The resulting molecular weight (30,500 +/- 800 g/mol) and partial specific volume (0.660 +/- 0.008 ml/g) are consistent with the idea that a sizeable fraction of the carbohydrate of high-molecular-weight kininogen is associated with the light chain. This level of precision is relatively easy to attain. The procedures are detailed, along with expressions for error propagation, to permit ready application of the technique.     

Overweight,Obesity, and Blood Pressure: The Effects of Modest Weight Reduction

Several large epidemiological studies have shown an association between body mass index and blood pressure in normal weight and overweight patients. Weight gain in adult life especially seems to be an important risk factor for the development of hypertension. Weight loss has been recommended for the obese hypertensive patient and has been shown to be the most effective nonpharmacological treatment approach. However, long‐term results of weight loss programs are disappointing with people often regaining most of the weight initially lost. In recent years, a modest weight loss, defined as a weight loss of 5% to 10% of baseline weight, has received increasing attention as a new treatment strategy for overweight and obese patients. A more gradual and moderate weight loss is more likely to be maintained over a longer period of time. Several studies have confirmed the blood pressure‐lowering effect of a modest weight loss in both hypertensive and nonhypertensive patients. A modest weight loss can normalize blood pressure levels even without reaching ideal weight. In patients taking antihypertensive medication, a modest weight loss has been shown to lower or even discontinue the need for antihypertensive medication. In patients with high normal blood pressure, a modest weight loss can prevent the onset of frank hypertension. The blood pressure‐lowering effect of weight loss is most likely a result of an improvement in insulin sensitivity and a decrease in sympathetic nervous system activity and occurs independent of salt restriction. In conclusion, a modest weight loss that can be maintained over a longer period of time is a valuable treatment goal in hypertensive patients.     

New Concept to Non-Invasively Screen Iron Deficiency in Patients

Nearly two billion people are afflicted with iron deficiency and approximately 300 million children globally have anemia. Most of those affected are unaware of their lack of iron, in part because detection of iron deficiency requires a blood test. It is becoming increasingly important to screen these individuals to reduce medical cost and avoid chronic disease conditions. There are limited settings of laboratory infrastructure for standard blood-based tests around the world to routinely accomplish this important screening test. We propose a new concept to use either human hair or nail as a screening method to detect steady state iron content in patients utilizing a sensitive portable magnetometer. The optimum hair/ nail sample weight should be determined for acceptable detection resolution (i.e., acceptable correlation with the results of blood test). The advantages of a portable device are as follows: non-invasive approach, point of care (on the spot) response with patient hair/nail sample to make screening much faster, and make screening for iron deficiency more available and affordable for patients around the world by eliminating current shortcomings of blood-based iron screening. The potential outcome of this concept is of great value to iron deficient patients. An easy, and cost-effective screening system will reduce morbidity, chronic diseases and medical cost substantially throughout the world.     

Lambs’ live weight estimation using 3D images

The sheep sector has not suffered the technification that other livestock sectors have. The lack of technological knowledge of the farmers and the economic limitations of the sector have made this technification difficult. One of the most widely used technologies is Precision Livestock Farming (PLF). PLF has already been used in other livestock sectors to improve farming efficiency. In the light of the problem that sheep farmers have in weighing lambs and their low precision, this paper proposes a system for estimating weight by means of 3D image capture. Thus, zenithal images of 272 lambs have been recorded. They have been processed using the capture of the upper area and the average depth of the pixels of the lamb. This estimates the weight of the animal with an error of less than 6%. This technology has a low economic cost and is easy to operate, helping farmers to be more willing to use it. This method manages to reduce the duration of the process, the stress of the animal and to improve the overall accuracy in weight estimation. Thus, it will help to have a greater control of the weight of the animal and to improve the economic profitability that the farmer obtains for the lambs.     

基于XML的物种属性构建系统

用PowerBuilder9．0开发了一个基于XML的物种及其属性构建系统,利用该系统可以方便的构建一个物种属性,并可以对该物种属性进行解析翻译。利用该系统以物种毛白杨作为实例进行构建,结果表示：该系统操作简便、构建灵活、能解析、方便读取、实用有效,对物种及其属性能够很好的描述,方便物种属性的管理。     

Contemporary management of renal trauma

In the management of renal trauma, surgical exploration inevitably leads to nephrectomy in all but a few specialized centers. With current management options, the majority of hemodynamically stable patients with renal injuries can be successfully managed nonoperatively. Improved radiographic techniques and the development of a validated renal injury scoring system have led to improved staging of injury severity that is relatively easy to monitor. This article reviews a multidisciplinary approach to facilitate the care of patients with renal injury.     

Ergonovine-Provoked Esophageal Spasm During Coronary Angiography

In many patients with chest pain of esophageal origin, findings are normal on routine esophageal manometry and dysmotility develops only upon provocation with ergonovine maleate. Unfortunately, ergonovine may induce myocardial ischemia in patients in whom coronary artery spasm did not occur during previous provocative testing in a cardiac laboratory—limiting its clinical usefulness. We have recorded esophageal pressure simultaneously with ergonovine infusion during angiography in ten patients without significant arterial stenoses. In two patients their usual chest pain developed associated with esophageal spasm and without changes in coronary vessels. Simultaneous performance of angiography and manometry enhanced the diagnostic yield of provocative testing by showing esophageal motility changes. This method may detect significant changes in the esophageal motility, is easy to carry out and does not interfere with angiography. It maximizes the information gained from a single provocative test and avoids the risk of ergonovine infusion outside of a cardiac laboratory.     

Altered response to metabolic challenges in mice with genetically targeted deletions of galanin-like peptide

Galanin-like peptide (GALP) is expressed in the arcuate nucleus and is implicated in the neuroendocrine regulation of metabolism and reproduction. To investigate the physiological significance of GALP, we generated and characterized a strain of mice with a genetically targeted deletion in the GALP gene [GALP knockout (KO) mice]. We report that GALP KO mice have a subtle, but notable, metabolic phenotype that becomes apparent during adaptation to changes in nutrition. GALP KO mice are indistinguishable from wild-type (WT) controls in virtually all aspects of growth, sexual development, body weight, food and water consumption, and motor behaviors, when they are allowed unlimited access to standard rodent chow. However, GALP KO mice have an altered response to changes in diet. 1) Male GALP KO mice consumed less food during refeeding after a fast than WT controls (P < 0.01). 2) GALP KO mice of both sexes gained less weight on a high-fat diet than WT controls (P < 0.01), despite both genotypes having consumed equal amounts of food. We conclude that although GALP signaling may not be essential for the maintenance of energy homeostasis under steady-state nutritional conditions, GALP may play a role in readjusting energy balance under changing nutritional circumstances.     

The possible role of intracellular polyamines in mitochondrial metabolic regulation.

Studies were made on the effects of very low concentrations of the polyamine, spermine, on rat liver mitochondrial metabolism associated with β-hydroxybutyrate. The respiratory control ratio and the rate of respiration during ADP-ATP conversion are significantly altered with shifts in spermine concentrations of as little as 15.7 nMoles/ml within the physiological Mg⁺⁺ concentration range. These spermine concentration changes are small compared to the estimated hepatic intracellular levels of spermine which have been reported to be between 200 and 1200 nMoles/gm wet weight under normal conditions. There is now evidence that exposure of an animal to certain environmental conditions induces changes of 164 nMoles/gm wet weight in intracellular levels of liver spermine in a few hours. Also there is evidence that the concentration of intracellular polyamines is influenced by endocrines since the levels of the enzymes responsible for their synthesis are markedly affected by hormonal changes. Therefore, alterations of polyamine levels may play a role in mitochondrial metabolic regulation $\text{in vivo}$.     

Patient's weight 6 months after depression treatment is not affected by either clinical remission or enrolment in collaborative care management

Objective The primary aim of this study was to determine whether enrolment in collaborative care management (CCM) for treatment of major depression would have a significant impact on 6-month changes in weight compared with patients treated by their primary care provider with usual care. The secondary aim was to determine whether clinical remission would also affect 6-month weight changes.Design A retrospective chart review study included 1550 patients who had been diagnosed with major depression or dysthymia and who had a Patient Health Questionnaire (PHQ-9) score of ≥ 10 with follow-up data (PHQ-9 score and weight) at 6 months.Subjects The study sample consisted of adult patients (aged ≥ 18 years) from primary care practices, representing all body mass index (BMI) categories. The exclusion criteria were a diagnosis of bipolar disorder, recent obstetric delivery or recent gastric bypass procedure.Measurements Weight was measured at index and 6 months, with BMI calculated from electronic medical record data. Patient assessment data (including PHQ-9 score and clinical diagnosis) and demographic variables (age, gender, marital status and clinical location) were also collected.Results With regression modelling, neither enrolment in CCM (P = 0.306) nor clinical remission (P = 0.828) was associated with a significant weight gain.Conclusion After 6 months, enrolment in CCM had no significant impact on weight gain or weight loss among patients treated for depression, nor was improvement to clinical remission a factor in the patient''s weight after 6 months. Incorporating a weight loss management intervention within the model may be warranted if concomitant weight reduction is desired.     

Effects of Brugia pahangi infection on the cardiovascular system of stroke-prone spontaneously hypertensive rats

To determine if filarial infection causes any effect on the cardiovascular system of the host animal, stroke-prone spontaneously hypertensive rats were infected with Brugia pahangi under the assumption that these rats would reveal pathological changes more clearly and in a shorter period than would ordinary rats. The infection resulted in loss of body weight, increase in heart weight, enlargement of left ventricle, and higher mortality rate.     

Effects of pressures inside Monterey pine trees

Summary The diurnal change in diameter of trees, aside from effects due to temperature, must be due to changes of pressure inside the tree. Monterey pines (Pinus radiata), as well as other pines, have two liquid systems, the sap system and the resin system. The sap is under a negative pressure, while the resin is under a positive pressure. Each system shows a diurnal change and, for these Monterey pines, the changes are in phase. The close agreement indicates that the changes in the one produce the changes in the other. These changes have been linked with the change in diameter of these trees by means of the modulus of elasticity of the wood. To gain further information on the effect of internal pressure on the diameter of the stem of a tree, caps were clamped on the ends of a section of a stem and the change of diameter was measured as water pressure was applied. Again, satisfactory agreement was obtained with that expected from the measured elasticity of the wood. The instruments developed to make these measurements, a dendrograph and a pressure recorder, are briefly described.     

Presuturing--a new technique for closing large skin defects: clinical and experimental studies

We have developed a new technique termed presuturing for aiding in the closure of large skin defects which may have otherwise required a skin graft or flap. This technique is based on biomechanical properties of skin (creep, stress relaxation) which allow skin to stretch beyond its inherent extensibility. Presuturing is performed under local anesthesia and consists of plicating intact skin over the area of planned excision the night prior to operation. Experimental studies in a pig model showed the decrease in force required to close a standard-sized wound to be 40.1 percent less than control (p less than 0.001). Fourteen patients who underwent wide excision of skin lesions had their wounds presutured. All but one wound could be closed primarily without undermining. Presuturing seems to be an easy and clinically useful technique in aiding the primary closure of large defects.     

核酸适配体在肿瘤免疫治疗中的应用

核酸适配体是指通过指数富集的配体系统进化技术(systematic evolution of ligands by exponential enrichment, SELEX)技术得到的一种可以高特异性、高亲和性识别靶标物质的单链DNA或RNA,可以作为靶向性治疗的分子探针。指数富集的配体系统进化技术即SELEX技术是在体外合成一个随机序列的文库,通过4个步骤孵育、分离、回收、扩增即可获得相对应的核酸适配体。通过几十年的发展,如今SELEX技术已成为一种重要的研究手段。核酸适配体具有稳定性强、分子量小、易进行化学合成和修饰、能特异性结合包括从小分子到细胞等靶标,识别范围广等优点,被广泛应用在肿瘤领域。免疫治疗与传统的肿瘤治疗方式不同,它是增强机体自身免疫系统来达到清除体内肿瘤细胞的一种方式,已被临床证明是治疗多种癌症的有效方法,例如针对免疫检查点CTLA4和PD-L1/PD-1的抗体,临床试验取得了成功,这为肿瘤的治疗带来了新的思路方法。目前,相关的免疫治疗药物已经上市应用于临床治疗,但是通过免疫治疗获益的肿瘤患者相对较少且会产生严重的副作用。核酸适配体与免疫相结合,为肿瘤的治疗提供了...