A study on the Pattern of Genetic Inheritance of Polycystic Ovarian Syndrome.

Aims: Inheritance of polycystic ovary syndrome (PCOS) is still a controversy. Our study aims to analyze the family history of PCOS features and related metabolic disturbances including the male members to determine the mode of their inheritance. Study Design: A cross sectional study with convenient sampling. Place and Duration of Study: Department of Medicine, Kasturba Medical College, Mangalore between 2009 and 2012. Methodology: Demographic data such as body weight and age was recorded. Menstrual, obstetric and medical history of 85 PCOS females was collected. Presence of metabolic syndrome (MetS) was confirmed. Blood pressure and waist circumference were measured. Biochemical and hormonal estimations were done. Relevant information required for the study of 604 members of first and second generation relatives was collected. SPSS (version 17.0) was used to analyze the data. Results: Seventy eight percent of the PCOS patients were either overweight or obese and 98% of them had hirsutism. Approximately, 33% of them had MetS which was higher in the first generation (62%) of PCOS relatives. An equal transmission of MetS characteristics from the paternal and maternal side indicated that it was not X- linked inheritance. Segregation analysis of nine families PCOS of patients suggested that MetS inheritance was autosomal dominant although PCOS inheritance was not. Conclusion: PCOS daughters come from families of MetS suggesting that parental MetS features may be related to the occurrence of PCOS in their off-springs.

Learning style preferences of preclinical medical students in a Malaysian university.

Background: Academic demands of medical students are quite high. They require several skills involving sensory components such as visual, auditory, reading-writing and kinesthetic modes. The academic performance naturally differs in students and depends on their study habits including the learning style. It is believed that self- confidence is the first requisite to great achievements. Objective: We undertook this study to establish our hypothesis based on the assumption that students’ self-confidence and academic performance are directly related and the differences in learning style of each student could influence the academic performance. Method: To explore the pattern of preferred learning styles of 82 students, we administered the VARK questionnaire to the participants. To assess self-esteem, Rosenberg self-esteem questionnaire was used and the academic performance was based on the overall results of the formative assessments. Results: Among the respondents, 84% preferred multimodal style of learning. Out of that, dual, trimodal and quadrimodal styles were preferred by 8.5%, 2.4% and 73.2% respectively. The remaining 16% of the students preferred single mode. Female students had more diverse learning style preferences with several VARK combinations. A large proportion of our students were in the average group in terms of self- confidence and academic performance. Conclusion: Most students in this study preferred multimodal inputs in their learning process. Our study did not reveal any major gender differences in preferred learning styles. The results of selfesteem, learning style preference and academic performance did not have any bearing on each other.

Recent advances in human brown fat physiology.

Of the two variants of adipose tissue, white fat is traditionally known as a lipid rich tissue which undergoes pathological expansion in obese conditions. To counter the excess accumulation of white fat in states of energy imbalance, the second and unique type of brown fat plays a key role by burning extra energy into heat through a special metabolic pathway. In addition brown fat also plays a vital role in thermoregulation in animals and newborn humans and infants. Recent progress in research areas of these two types of fat tissue has provided compelling evidence to show that they secrete a large number of chemicals that play an important role in body weight control that involves several mechanisms. Brown fat was considered absent in the adult humans until recently. But new techniques have provided ample support for its active existence. Based on the very recent data it has been suggested that brown fat can be a target organ in the treatment of obesity which can lead to exciting and informative outcomes in the future.

Body fat and lean body mass assessment in human subjects--a comparison of two different techniques.

Body fat and lean body mass was assessed in young college students by two different techniques involving NIR method and body circumference measurements. NIR technique significantly over-estimated the body fat as compared to the results obtained by the other method. The difference between the methods was 23-30% high for fat and the variation was 5-9% low for lean body mass for the whole group. Results obtained by the body girth size measurements agreed well with fat and lean body mass values from other studies on Indian subjects which had employed different methods.

Differing response of body weight gain to high fat diet treatment in the mouse.

Forty-eight mice maintained on a high fat diet supplement in addition to regular laboratory rodent chow responded differently in terms of body weight gain over a period of six weeks. Eleven mice gained weight that was comparable to body weights of mice given only chow for the same period of time while the others gained significantly higher body weights and became obese despite similar level of energy intakes. The increase in body weight was due to increase in body fat content as noted by carcass analysis. The differential response of the mice to identical dietary treatment in causing obesity or not in mice is discussed.

Alcohol dehydrogenase activity in mouse brown adipose tissue.

The present work provides evidence for the occurrence of the enzyme alcohol dehydrogenase (ADH) in very minute concentration in mice brown adipose tissue (BAT). Mice consuming 10% ethanol for 10 days showed significantly lowered enzyme activity in brown fat while liver ADH activity was increased but not significantly. Measurements of basal and norepinephrine stimulated oxygen consumption of isolated brown adipocytes indicated that the presence of ADH in BAT of mice is unlikely to play any role in ethanol oxidation.

Metabolic responses to episodes of partial dietary restriction in undernourished Wistar rats.

Wistar rat pups raised in large litters (LL) and small litters (SL) prior to weaning had access to ad libitum dietary intakes up to the age of 90 days. At 90 and again at 180 days they were partially diet restricted for a period of 15 days. Body weights, resting metabolic rates (RMR) and capacity for nonshivering thermogenesis (NST) was evaluated prior to, during and after the period of energy restriction. Responses were compared with 180 day rats from both groups who had been diet restricted for the first time at 180 days. Body weight losses were greater in the latter group. Groups of rats exposed to dietary restriction once, had higher body weights than rats of identical ages who had not been restricted. RMR decreased in all groups during restriction. However, reductions in NST were seen only in nutritionally deprived animals and in well-nourished controls who were partially restricted once. Changes in NST contribute to metabolic efficiency seen during episodic dietary restriction.

The impact of early undernutrition on voluntary food consumption in later life of rats.

Food consumption patterns were studied during ad-libitum feeding of rats undernourished for 21 or 60 days after birth. Rats undernourished for 21 days consumed less food than the controls on a whole animal basis. But the food intake was higher during the early part of ad-libitum feeding when expressed on a unit body weight or metabolic body weight basis, and subsequently became comparable to that of the controls. Male rats undernourished for 60 days showed either comparable (for the whole animal) or higher (in other terms) food consumption, whereas the female rats undernourished for 60 days consumed more food at the beginning of ad-libitum feeding but less food during the latter part, when compared to their respective controls. The results thus indicate that no single mechanism can completely explain the food intake of undernourished rats during nutritional rehabilitation.

Sucrose feeding stimulates basal metabolism & nonshivering thermogenesis in undernourished rats.

Undernutrition in rats for 60 days from the first day of birth resulted in a significant diminution of nonshivering thermogenesis (NST) and basal metabolic rate (BMR; 12.5 and 5% respectively) as compared to their controls, even when expressed on a metabolic body weight basis. Sucrose (8%) feeding for 72 h of such undernourished (UN) rats immediately after 60 days reverted the depressed NST capacity to levels comparable to control values while the BMR was higher by about 9 per cent than controls. The actual increase in NST and BMR of UN rats after 72 h of sucrose feeding was about 12 and 14 per cent respectively when compared to the values before sucrose feeding. This is possibly because sucrose feeding is known to elevate the caloric intake by 20-30 per cent over normal and would stimulate the sympathetic nervous system (SNS) activity. The results thus would imply that the reduced NST and BMR in rats consequent to undernutrition is probably due to diminished SNS activity which may be associated with changes in some hormonal and brown adipose tissue functions. However, such changes appear to be limited only to the period of undernutrition as it can be corrected speedily by adequate energy supplementation.

Basal metabolic rate, nonshivering thermogenesis and cold tolerance in rat during undernutrition and subsequent nutritional rehabilitation.

Nutritional deprivation induced by increasing the litter size and subsequent dietary restriction results in rats having lower body weights and body lengths. Such undernourished rats have lower body temperatures as well as lower basal metabolic rate and nonshivering thermogenesis on a metabolic body weight basis; they also succumb on cold exposure to 5 degrees C. Nutritional rehabilitation by access to unlimited food reverses these changes to levels comparable to their control values.

Nutritional status and spontaneous locomotor activity in the rat.

A considerable amount of energy may be saved by lowering the spontaneous locomotor activity when energy intakes are reduced. The results of the present study in rats undernourished for a period of 21 or 60 days and subsequently fed ad libitum diet did not show any differences in activity when compared to their respective control groups, either during the undernourished periods or well fed states. Although this would mean that the rats are not economising energy on activity, it is probable that these rats with lower body weights are contributing to energy saving mechanism by reducing the cost of activity per se since the cost of activity and body weight are directly related.

Cold-induced thermogenesis in rats nutritionally deprived early in life.

Preweaning nutritional deprivation with or without postweaning partial energy restriction produces animals of small size with defective nonshivering thermogenesis. This is also associated with their inability to tolerate cold exposure to 5 degrees C. Adequate nutritional rehabilitation for a reasonable length of time of 10 days abolishes the defect in cold induced thermogenesis (CIT) although the deficits in body weight or body size are not corrected. This may indicate that the defect may be possibly due to the non availability of enough substrates rather than to a change in the functioning of thermogenic organs such as brown adipose tissue. Sucrose feeding which enhances caloric intake and hence sympathetic activity can reverse the defect in CIT only in older rats suggesting the possibility of delayed maturation of thermoregulatory functions in young rats which are energy deprived. The results of this study possibly indicate that there may be a temporary reduction of the sympathetic nervous system activity during the period of energy restriction which compromises cold tolerance and which is reactivated rapidly following nutritional rehabilitation.

A closed circuit apparatus for measurement of oxygen consumption in small animals.

A simple and reliable closed circuit apparatus for short term and long term measurements of oxygen consumption of small laboratory animals is described. Repeat measurements of oxygen consumption under resting conditions of six male albino rats using this apparatus shows a variability of less than 1.5%. Use of the set-up for continuous monitoring of oxygen consumption following subcutaneous injection of norepinephrine, for over 2.5 hr enables the measurement of energy expenditure in animals on a long term basis which is reproducible on several occasions.