This study was conducted to investigate the utility and efficacy of finger photoplethysmogram pulse amplitude (PPG-AC) in comparison with the standard Doppler ultrasound in assessing an endothelial function via flow-mediated dilation (FMD). High-resolution B-mode scanning of the right brachial artery (BA) of 31 healthy subjects aged 39.7 +/- 11.3 (range 22-64) years and 52 risk subjects aged 47.7 +/- 10.8 (range 30-65) years were performed before and after 4 min of upper arm occlusion. Concurrent with the ultrasound measurement (where color Doppler imaging was used to enhance arterial boundary detection), PPG signals were recorded from both index fingers for cross evaluation and comparison. Our results show that the finger PPG-AC exhibits a similar response to that of the well-known BA dilation: following the release of pressure (cuff around the BA), the PPG-AC increases abruptly before slowly decreasing toward the baseline. The peak PPG-AC is reached significantly faster than the peak FMD measured by ultrasound among healthy and risk groups (P < 0.001). The proposed technique using a finger photoplethysmogram can be applied in a rapid and non-invasive assessment of peripheral vascular functions as an alternative low-cost and less operator-dependent tool compared to ultrasound.

The aim of this study was to identify risk factors associated with osteoporosis in urban midlife Malaysian women and to assess the effectiveness of lifestyle intervention in bone loss prevention with hormone replacement therapy (HRT) as a positive control. A total of 514 disease-free, uterus-intact, non-HRT-using women aged 45 years and older were recruited into the study. After initial bone mineral density (BMD) assessments, they were randomized into three groups: GI (control), G2 (lifestyle intervention), and G3 (lifestyle intervention with HRT). The study group was composed of 67.5% Chinese, 27.8% Malay, and 4.2% Indians with a mean age of 51.07+/-5.28 years. Two-fifths were postmenopausal, and the prevalence of osteoporosis was 24.1%, seen predominantly at the hip. Postmenopausal women had significantly lower mean BMD and a higher incidence of osteoporosis compared with the premenopausal women, 42.1% vs. 11.1% (p<0.0005). A lower incidence of osteoporosis was found in women who took calcium supplementation regularly as opposed to those who do not, 18.7% vs. 29.3% (p=0.036). Age and a greater postmenopausal duration showed a significant negative association with BMD, whereas higher family income, weight, body mass index, and waist and hip circumference were positively correlated. After 18-20 months, the effect of intervention was assessed based on BMD values of 279 women at baseline and after intervention. Lifestyle intervention alone was effective in premenopausal women, preventing over 90% of spinal bone loss compared with the controls, who lost 11.6% (0.046 g/cm2) bone mass with similar losses of hip bone, 2.0% (0.026 g/cm2) vs. 1.5% (0.020 g/cm2). Premenopausal women on HRT also showed a substantial decrease in spine and hip BMD, 18.6% (0.081 g/cm2) and 9.0% (0.122 g/cm2), respectively. The lifestyle intervention program retarded postmenopausal bone loss by 21% and 37% compared with controls, who lost 9.6% (0.141 g/cm2) and 6.0% (0.138 g/cm2) bone mass at the spine and hip. In comparison, lifestyle intervention with HRT increased postmenopausal BMD by 12.7% (0.216 g/cm2) at the spine and 1.9% (0.042 g/cm2) at the hip. The changes in hip BMD were influenced by current age, ethnicity, and income, while intervention had the strongest effect on spine BMD changes. In conclusion, lifestyle intervention prevented spinal bone loss in premenopausal women and retarded postmenopausal spine and hip bone loss compared with controls. The benefits of physical activity on spine and hip BMD highlight its potential as a safe and cost-effective alternative to HRT, which is not advocated because of its potential adverse effects.

The genetic variation of Trigonobalanus verticillata , the most recently described genus of Fagaceae, was studied using chloroplast DNA sequences and AFLP fingerprinting. This species has a restricted distribution that is known to include seven localities in tropical lower montane forests in Malaysia and Indonesia. A total of 75 individuals were collected from Bario, Kinabalu, and Fraser's Hill in Malaysia. The sequences of rbc L , mat K, and three non-coding regions ( atp B -rbc L spacer, trn L intron, and trn L -trn F spacer) were determined for 19 individuals from these populations. We found a total of 30 nucleotide substitutions and four length variations, which allowed identification of three haplotypes characterizing each population. No substitutions were detected within populations, while the tandem repeats in the trn L -trn F spacer had a variable repeat number of a 20-bp motif only in Kinabalu. The differentiation of the populations inferred from the cp DNA molecular clock calibrated with paleontological data was estimated to be 8.3 MYA between Bario and Kinabalu, and 16.7 MYA between Fraser's Hill and the other populations. In AFLP analysis, four selective primer pairs yielded a total of 431 loci, of which 340 (78.9%) were polymorphic. The results showed relatively high gene diversity ( H S = 0.153 and H T = 0.198) and nucleotide diversity ( π S = 0.0132 and π T = 0.0168) both within and among the populations. Although the cp DNA data suggest that little or no gene flow occurred between the populations via seeds, the fixation index estimated from AFLP data ( F ST = 0.153 and N ST = 0.214) implies that some gene flow occurs between populations, possibly through pollen transfer.

Neutrophils play a significant role in maintaining the integrity of innate immunity via their potent respiratory burst activity. However, the uncontrolled activation of respiratory burst in neutrophils also attributes to chronic diseases such as primary hypertension and atherosclerosis. In our study, we have investigated the activation of respiratory burst function of neutrophils harvested from essential hypertensive patients. In the presence of stimuli PMA and opsonized zymosan (OZ), hypertensive patients' neutrophils secrete significantly higher amount of superoxide anions compared to normotensive control. Although the magnitude of activation varies between both groups, yet the kinetics of activation is similar. When normotensive control's neutrophils were pre-treated with hypertensive serum, the cells failed to migrate toward fMLP which indicates the impairment of the migration property. In conclusion, the respiratory burst activity of neutrophils is affected by hypertension and their elevated superoxide anions production could be an aggravating factor in hypertension-related complication.

There have been many models proposed in the past decade on the best practices in teaching and learning processes, especially in medical education. The main trend is a major shift from tutor-centered system to student-centered learning processes with the aid of information technology and communications, more often called e-learning. The introduction of problem-based learning (PBL) and student centered team based learning SCTL) in the early 80's became a trend which spread like wildfire in most modern medical schools. The acceptance of these new methodology received different reactions, mainly from the tutors, most of whom were split on whether the need of change was really necessary, asking the main question of "what is wrong with the traditional methods" or "have we produced inefficient doctors through the years of traditional system teachings". It seemed for some time that a significant number of older generation tutors were much more comfortable with the methods they were used to. Considerable curricular changes were made by many medical institutes to implement the student centered learning system. This approach, however, necessitated the training of tutors and the creation of a learning environment, which was later found not to be too easy. The major consideration of a shift in techniques of teaching learning processes is the understanding of the trends in the younger generation of the Y2K century. A generation which prefers to express rather than listen, to research and find rather than being spoon-fed and a generation where knowledge is always available whenever they are connected to the internet. Hence the change of the role of tutors to be facilitators rather than content providers was seen to be more acceptable to the new generation of students. The advancing information technology (IT) has been able to provide the necessary tools to achieve that objective. The students may be granted the opportunity to have more freedom in selecting their learning material and to enjoy a degree of distance-learning. The consequence of applying IT in medical institutes would, probably, enforce the trend towards moving to a student-centered learning environment, inducing hesitant tutors to become more compliant with the change. The future medical curriculum is anticipated to be more student-centered, more modular, more integrated, more PBL or SCTL-oriented and more inter-institutionalized, with less memorizing and with more learning about learning. In addition, medical education as a whole at least in part, would be, performed at distance. The future medical tutor may have to be more PBL-oriented, more qualified in learning strategies, competent in small group (probably single-student) learning, more of a 'mentor' or a 'facilitator' than of a 'teacher', able to train students at higher cognitive levels rather than being an 'authority' in its field. He has no choice but to be fluent in IT, and interactive with learning via other learning-collaborating institutions. Key Words: Medical education. DOI:10.3329/bjms.v9i1.5226 Bangladesh Journal of Medical Science Vol.09 No.1 Jan 2010 4-13