Dynamic clamp with StdpC software

Dynamic clamp is a powerful method that allows the introduction of artificial electrical components into target cells to simulate ionic conductances and synaptic inputs. This method is based on a fast cycle of measuring the membrane potential of a cell, calculating the current of a desired simulated component using an appropriate model and injecting this current into the cell. Here we present a dynamic clamp protocol using free, fully integrated, open-source software (StdpC, for spike timing-dependent plasticity clamp). Use of this protocol does not require specialist hardware, costly commercial software, experience in real-time operating systems or a strong programming background. The software enables the configuration and operation of a wide range of complex and fully automated dynamic clamp experiments through an intuitive and powerful interface with a minimal initial lead time of a few hours. After initial configuration, experimental results can be generated within minutes of establishing cell recording

Re-Evaluation of the Action Potential Upstroke Velocity as a Measure of the Na+ Current in Cardiac Myocytes at Physiological Conditions

Background: The SCN5A encoded sodium current (INa) generates the action potential (AP) upstroke and is a major determinant of AP characteristics and AP propagation in cardiac myocytes. Unfortunately, in cardiac myocytes, investigation of kinetic properties of INa with near-physiological ion concentrations and temperature is technically challenging due to the large amplitude and rapidly activating nature of INa, which may seriously hamper the quality of voltage control over the membrane. We hypothesized that the alternating voltage clamp-current clamp (VC/CC) technique might provide an alternative to traditional voltage clamp (VC) technique for the determination of INa properties under physiological conditions. Principal Findings: We studied INa under close-to-physiological conditions by VC technique in SCN5A cDNA-transfected HEK cells or by alternating VC/CC technique in both SCN5A cDNA-transfected HEK cells and rabbit left ventricular myocytes. In these experiments, peak INa during a depolarizing VC step or maximal upstroke velocity, dV/dtmax, during VC/CC served as an indicator of available INa. In HEK cells, biophysical properties of INa, including current density, voltage dependent (in)activation, development of inactivation, and recovery from inactivation, were highly similar in VC and VC/CC experiments. As an application of the VC/CC technique we studied INa in left ventricular myocytes isolated from control or failing rabbit hearts

Die invloed van fisieke aktiwiteit en leefstyl op koronêre gesondheid

Physical activity and lifestyle choices may have a significant impact on theindividual’s health status. The health status of the employee has a direct impact on his/her productivity, thus influencing the success of any business. The aim of this study was to determine the influence that physical activity and lifestyle choices has on the coronary health status of employees at an electricity supply company in South Africa. One hundred and seventy nine (N=179) volunteers took part in the study. The physical activity index of the participants was determined by the use of Sharkey and Gaskill’s (2007) Physical Activity Index questionnaire (PAI). The lifestyle index was determined by the use of Belloc and Breslow’s (1972) Lifestyle Index questionnaire (LI) and the coronary risk index was determined by the use of Bjürstrom and Alexiou’s (1978) Coronary Index questionnaire (CRI). The respondents’ ages varied between 25 and 65 years ( x = 46.1 ± 9.5). Analysis of the data identified age, gender, exercise and stress to be the four major contributers to coronary heartdisease. The majority of employees were unaware of their cholesterol, systolic and diastolic blood pressure status. The relationship between the level of physical activity participation and lifestyle choices with the development of coronary heart disease was determined by the use of the Tuckey Post Hoc test. This information can be helpful with the planning of wellness programs. These wellness programs aim to improve the employees’ coronary health status by motivating them to increase their level of physical activity and make better choices in terms of lifestyle behaviors

Physical activity and physical fitness profiles of South African women

The purpose of this study was to determine the leisure time physical activity (LTPA) participation and physical fitness (PF) levels of South African women of the various ethnic groups. Individuals between the ages of 30 and 60 years (x=41.0; ±=4.6) who were part of a cross-sectional non-randomized availability population who voluntarily participated, were used in this study. The group that formed part of the physical activity survey included 3273 subjects (Asian =262; black=1357; coloured=239; white=1415) while the group for the physical fitness analysis included 3060 subjects (Asian=248; black=1015; coloured=199; white=1225). Subjects who used medication such as beta-adrenergic suppressors that could affect the fitness test were excluded from participating. Statistical analysis was done using the CSS: Statistica computer software to determine profile analysis of the participants. The results indicated that 85% of coloured women reported low physical activity participation, followed by black and Asian women where 83% of the participants indicated low physical activity participation, while 75% of white women revealed low physical activity levels. In contrast, 10% of the white women indicated high LTPA participation while only 5% of coloured women were very active. In the case of black and Asian participants, 8% and 6% respectively indicated high LTPA levels. Regarding physical fitness, 57%, 50%, 49% and 39% of the black, Asian, coloured and white respondents respectively showed low physical fitness levels, while 10%, 6%, and 5% of the white, Asian/black and coloured respondents showed high levels of physical fitness. This high prevalence of physical inactivity and unfitness may lead to various health problems and can increase the prevalence of hypokinetic ailments in adult women, increased health care costs and even premature death.Key words: Physical activity, physical fitness, women, hypokinesis

Postural deformities in children: A review

Postural deformities are a commonly encountered problem among children. Most of the aches and pains of adults are the result, not of injuries, but of the long-term effects of distortions in posture or alignment that have their origins in childhood or adolescence. Television, video entertainment, motorized transportation, fast food and lack ofregular physical activity contribute to the poor physical condition of children. Childhood obesity has increased dramatically in the past decade.Countries in economic transition from underdeveloped to developed, such as South Africa, are particularly affected and have an increasingprevalence of obesity across all economic levels and age groups. In a developing country like South Africa, where overweight/obesity co-exists with undernutrition, there is an urgent need to prevent unhealthy trends in diet and physical activity. School screening is mandatory in schools in 26states of the United States (US) for children between 10 and 16 years of age. Previous studies conducted in the US found that 160 out of 1000 people suffer from scoliosis (Boachie-Adjei & Lonner, 1996). This means that scoliosis is as prevalent as hypertension or diabetes mellitus. Identification of postural deformities at an early stage makes earlytreatment possible, which may, in future, prevent serious postural abnormalities. The aim of this review article is to define the concept of good posture, analyze normal postural development and postural deformities, and discuss some of the developmental factors affecting posture.

A conceptual framework of Biokinetic procedures and referral system: An integrated protocol for the various health paradigms

Physical activity as a therapeutic modality has been prescribed by health professionals for various ailments since ancient times. Research has proved this positive relationship and recent initiatives suggest that exercise should be prescribed just as medicine or any drug would be – theso-called “Exercise is Medicine” initiative in the USA at present. In an equally important way physical activity serves a pivotal role in health promotion. This implies that biokinetics, which is the profession mainly using scientifically prescribed exercise as a modality, serves in both the pathogenic as well as the fortogenic health paradigms. The pathogenic paradigm refers to either the presence of an illness (ill care) or to the threat of an illness (illness prevention). In both of these constructs pathology is of key importance. In the fortogenic paradigm (health promotion) the focus primarily falls on improving the strong points with no threat of pathology. However, these constructs are not isolated, but interact intimately with each other. This can be illustrated by means of a schematic diagram. biokinetics as the profession using exercise and physical activity as the primary modality of treatment, therefore, is closely linked to the various constructs. This implies that referral to the biokineticist may come from the clinical as well as the non-clinical environment and that the biokineticist, as a professional who is registered with the HPCSA, should ensure working within the scope of the ethical rules. The referrals from the clinical as well as the non-clinical environment can be more clearly described by means of a conceptual framework constructed for the biokinetic practice.Key words: Biokinetics, health paradigms, referral, procedures, ethical rule

Leisure time physical activity participation in women (30-65 years) with high coronary heart disease risk indicators

The aim of this study was to determine the effect of leisure time physical activity participation (LTPA) on South African women presenting with some enhanced coronary heart disease (CHD) risk indicators (physical inactivity, hypertension, hypercholesterolemia, obesity and smoking). The respondents comprised 3 542 women, aged between 30 and 65 years (X41.6 +- 12.8 years) suffering from one or more of the primary risk factors for CHD. The cut-off points for the primary CHD risk factors considered were the following: systolic blood pressure > 140 mmHg, diastolic blood pressure > 90 mmHg, total cholesterol > 5.2 mmol.L-1, obesity (BMI > 30) and cigarette smoking. The following physical activity categories were selected viz: high physically active (> 2 000 kcal.week-¹), moderate physically active (1 000 – 2 000 kcalweek-¹) and low physically active (< 1 000 kcal.week-¹). Data were collected by means of demographic and physical activity questionnaires as well as field tests, and assessing total cholesterol, blood pressure and obesity. The respondents were selected from two age groups (30-49 and 50-65 year) representing primarily the pre- and postmenopausal phases of female life. Leisure time physical activity participation does not alter the selected primary coronary heart disease risk factors in the pre- and post-menopausal women significantly. Physically inactive women, however, tend to present more health risks than those participants in the moderately and high physical activity group. The prevalence of health risks increases with age inspite of participation in LTPA. The number of health risk indicators can be reduced by increasing LTPA, thus contributing to the management of the women‘s general health. Women should be encouraged to take responsibility for managing their own health by engaging in a healthy lifestyle in order to manage their health risks properly. This may require a multidisciplinary approach.Key words: Women, hypertension, hypercholesterolemia, obesity, smoking, physical inactivity

Influence of physical fitness on some selected blood lipids in pre-and post-menopausal women

There's no better time than the years surrounding menopause for a woman to start or renew an exercise programme. Exercise may reduce the immediate symptoms of menopause, and it decreases the long-term risk of cardiovascular disease, osteoporosis, depression and obesity. Data were gathered from 250 pre-menopausal (35-49 years) and 107 post-menopausal women (50-64 years) who formed part of a comprehensive community study. The purpose of this study was to determine the influence of physical fitness on total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglycerides in pre- and post-menopausal women. Physical fitness was expressed as physical working capacity (PWC170), which was determined by a progressive cycle ergometer test. Statistical significant differences (

An analysis of phyisical work capacity, serum liquid ratios and influence of cigarette smoking in South African women aged 35-64 years

No Abstract

Physical activity, lifestyle and leisure constraints in a selected female population

Research has revealed that physical activity and a healthy lifestyle are inter alia considered as crucial factors in maintaining optimal health. These relationships are however influenced by age and sex. Women are often constrained in their ability to reach optimum levels of physical activity participation and healthy lifestyle. The aim of this study was to determine the relationship of physical activity participation and lifestyle with the constraints experienced by a selected group of women. The respondents in this study included 440 South African Caucasian women, aged 30-65 years ( x = 42.98 ± 9.34) that were randomly selected in an urbanised community. Data were collected by using questionnaires reporting demographic information as well as physical activity participation, lifestyle and constraints to participation. From the descriptive data, it is clear that the most frequently reported individual constraints are those associated with the ambivalent role of women in their daily life. Physical activity and lifestyle showed individual significant relationships with the total constraints to participation of women. Using one-way analysis of variance it became clear that when constraints for participation decrease, the lifestyle of women became significantly (p £ 0.05) better. A multiple regression analysis indicated that lack of opportunities, work and school responsibilities, insufficient money, lack of friends to participate with, family responsibilities, feelings of guilt, poor health and lack of time, contribute significantly (p £ 0.05) to total constraints regarding participation.Key words: Female, physical activity, lifestyle, leisure constraints