Implementation of surface mechanomyography as a novel approach for objective evaluation of phasic muscle stretch reflexes in people with type 2 diabetes.

INTRODUCTION: Diabetic peripheral neuropathy is the most common complication of diabetes producing metabolic disruptions in the peripheral nervous system. Alteration in the predictable nature of tendon reflexes is the most common indicator suggesting the possibility of diabetic neuropathy. Evaluation of tendon reflexes is a part of various clinical scoring systems that assess neuropathy. The conventional reflex grading scales are subjective, lack temporal data, and have high inter-rater variability. Hence, an indigenous quantification tool was developed to evaluate the tendon reflexes in order to assess diabetic peripheral neuropathy. MATERIALS AND METHODS: A cross-sectional study was carried out in 140 healthy volunteers and 140 patients with type 2 diabetes. The mean age of controls and diabetics (49.1 ± 8.9, 50.7 ± 7.5) years, weight (66.9 ± 9.4, 69.8 ± 11.5) kilograms and BMI (24.5 ± 3.8, 26.1 ± 4.7), respectively. All of them are subjected to evaluation of tendon reflexes using the reflex quantification tool comprised of surface mechanomyography and electrogoniometry that can provide various static and dynamic variables of tendon reflex. RESULTS: The dynamic variables such as reflex amplitude, muscle velocity and angular velocity were significantly low in diabetic patients (p: <0.001) whereas latency and duration (p: <0.001) were prolonged. Furthermore, no significant difference was observed in the application of tendon striking force (p: 0.934) among the participants. CONCLUSION: The current study demonstrates that the proposed reflex quantification tool provides several dynamic variables of patellar tendon reflex, which are significantly affected and altered in diabetic patients suggesting the involvement of peripheral neurons.

Effects of Therapeutic Calf Massage on Cardiac Autonomic Function in Healthy Volunteers-a Pilot Study.

Background: Calf massage is a therapeutic intervention that improves circulation and relieves us from pain & tightness. The calf massage also improves autonomic performance by modulating the vagal tone of the cardiovascular system. Therefore, the current study was intended to determine therapeutic calf massage on cardio autonomic activity in healthy subjects. Objective: To assess the immediate effect of a single 20-min session of calf massage on cardiac autonomic modulation through heart rate variability (HRV) measurement. Materials & Methods: In this study, 26 apparent healthy female participants aged between 18 and 25 years participated. Massage over the calf muscles on both legs for 20 min was performed, and resting cardiovascular parameters and HRV parameters were measured at baseline, immediately after the massage, and during the recovery periods (10 and 30 min after the massage). Data were analyzed using one-way ANOVA followed with post hoc analysis. Results: Immediately after the massage intervention, heart rate (HR), systolic (SBP), and diastolic (DBP) blood pressure were decreased (p < .01), and the reduction was persisted at 10 min and 30 min of the recovery period (p < .01). In HRV parameters, the root mean square of successive differences (RMSSD) and high-frequency normalized unit (HF n.u.) increased, and low frequency (LF n.u.) decreased after the massage, and at the 10 and 30 min of the recovery period. Conclusion: The present study reports suggest a significant reduction in heart rate and blood pressure after the massage therapy. A drop in sympathetic tone and raise in parasympathetic tone can also attribute to the therapeutic effect.

Prevalence of vitamin D deficiency among South Indian pregnant women.

Background: Deficiency of vitamin D is widespread across the globe. Expectant women are one of the most vulnerable groups for vitamin D deficiency (VDD). Even in South India with abundance of sunlight, pregnant women are believed to be at a high risk of this deficiency. The objectives of this study are to assess the prevalence of VDD in antenatal women, associate it with modifiable risk factors and evaluate its correlation with low birth weight. Methods: This cross-sectional study was conducted in a tertiary care hospital, in Chennai, in 100 pregnant women in their last trimester on the basis of inclusion and exclusion criteria and their vitamin D and calcium levels were assessed. A detailed history regarding physical activity, diet, and sun exposure were collected and results were analyzed. Results: The point prevalence of VDD (serum 25-hydroxyvitamin D (25(OH) D) level <20 ng/mL) among antenatal women in our study is 62%. Univariate analysis revealed that sun exposure and socioeconomic status were the significant factors associated with higher percentage of VDD. Linear regression analysis showed that only sun exposure was a significant predictor for serum 25(OH) D levels. VDD is also associated with increased risk of low-birth-weight babies. Conclusion: VDD is highly prevalent among pregnant women in South India leading to adverse health consequences in the mother and offspring. Less physical activity, decreased sun exposure, darker skin complexion, lower socioeconomic status and lack of awareness are the major risk factors associated with VDD in our study population.

Validation of Internal structure of Self-Directed Learning Readiness Scale among Indian Medical Students using factor analysis and the Structural equation Modelling Approach.

BACKGROUND: The Self-Directed Learning Readiness Scale (SDLRS) is a tool that helps in the assessment of the readiness of the students to pursue Self-Directed Learning (SDL). There are no documented studies on the validation of internal structure of the SDLRS among Indian medical students. Hence, the objective of this study is to validate the internal structure of SDLRS among Indian medical students using factor analysis and the Structural Equation Modelling (SEM) approach. METHODS: We administered Fisher's 40-item SDLRS to 750 students after receiving the ethics clearance and the author's permission and taking written informed consent from all the study participants (response rate: 92%). The exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and Cronbach's alpha were performed using SPSS version 25 and the Lavaan package of R version 3.1.2. RESULTS: The values of the comparative fit index (CFI), standardised root-mean-square residual (SRMR), and root mean square error of approximation (RMSEA) were ≥ 0.9, ≤ 0.08, and ≤ 0.08, respectively, for a model fit to be acceptable. EFA showed that except for Q2 (loading score: 0.210), Q12 (loading score: 0.384), Q13 (loading score: 0.362), and Q25 (loading score: -0.219), all the items loaded well. After the exclusion of the aforementioned items, the factor loading scores for the items in the self-management, desire for learning, and self-control factors ranged from 0.405 to 0.753 (Cronbach α: 0.775), 0.396 to 0.616 (Cronbach α: 0.730), and 0.427 to 0.556 (Cronbach α: 0.799), respectively. The updated model was used for CFA, which displayed a good model fit. CONCLUSIONS: The resultant model consisting of 36 items is shown to have internal structure validity for Indian version of SDLRS, which can be used to assess medical students.

Impaired pupillary light reflex indices in Orbital Apex Syndrome - A rare case report.

BACKGROUND: The clinical presentation of reduced pupillary responses in orbital apex syndrome is currently not well understood clinically. The pupillary light reflex (PLR) is determined using dynamic pupillometry. CASE DETAILS: A newly diagnosed 35-year-old diabetic female patient had ocular symptoms including orbital pain and ptosis, but no visual loss. Cranial nerve autonomic impairment was identified with dynamic pupillometry and compared with cardiac autonomic activity using heart rate variability (HRV). RESULTS: PLR showed that pupil size and response were severely affected, with a small resting pupil size, and minimal response to a bright white light flash was seen, due to decreased sympathetic activity. However, HRV showed normal cardiac sympathetic activity. CONCLUSION: These findings suggest that orbital apex syndrome may lead to changes in pupil size and response due to compression of sympathetic fibers at the apex of the orbit. Quantitative PLR measurements help to reveal relevant information on anatomical reflex pathways.

Meta-analysis of association between il-6-174 g/c polymorphism and female infertility related disorders.

Female infertility continues to increase in prevalence annually and factors causing it need to be researched. As IL-6-174 G/C polymorphism is known to alter the plasma levels of IL-6, abnormal levels of IL-6 found in infertile females could be due to genetic reasons. With the understanding of the importance of IL-6 in reproductive physiology, several individual studies done so far to find the association of this polymorphism with female infertility related disorders were systematically combined for meta-analysis. Articles were searched using electronic data base sources and were included based on specific criteria. Finally, eight articles which includes polycystic ovarian syndrome (PCOS; n = 4), endometriosis (n = 3) and tubal damage (n = 1) were selected for the analysis. Results showed statistically significant heterogeneity across studies under the allele model (p < 0.0001, I2 = 78 %) and dominant model (p < 0.00001, I2 = 82%) but not under recessive model (p = 0.31, I2 = 16%). This difference could be possibly due to variation in ethnicity, lifestyle, age or BMI related factors. The pooled odds ratio under the three genetic models were 0.87(CI = 0.75-1.02), 0.77 (CI = 0.63-0.94) and 1.05 (CI = 0.76-1.46) respectively. Sub group analysis showed statistical significant (P < 0.01) for PCOS under allele and dominant model, but not for endometriosis and tubal damage. By this meta-analysis, we can say that IL-6-174 G/C polymorphism can be considered as a potential genetic marker for PCOS but not for endometriosis and tubal damage disorders. However, more studies with adequate sample sizes are required to be done in endometriosis, tubal disease and other female infertility disorders to arrive at a definite conclusion.

Validation of PC-based Sound Card with Biopac for Digitalization of ECG Recording in Short-term HRV Analysis.

BACKGROUND: Heart rate variability (HRV) analysis is a simple and noninvasive technique capable of assessing autonomic nervous system modulation on heart rate (HR) in healthy as well as disease conditions. The aim of the present study was to compare (validate) the HRV using a temporal series of electrocardiograms (ECG) obtained by simple analog amplifier with PC-based sound card (audacity) and Biopac MP36 module. MATERIALS AND METHODS: Based on the inclusion criteria, 120 healthy participants, including 72 males and 48 females, participated in the present study. Following standard protocol, 5-min ECG was recorded after 10 min of supine rest by Portable simple analog amplifier PC-based sound card as well as by Biopac module with surface electrodes in Leads II position simultaneously. All the ECG data was visually screened and was found to be free of ectopic beats and noise. RR intervals from both ECG recordings were analyzed separately in Kubios software. Short-term HRV indexes in both time and frequency domain were used. RESULTS: The unpaired Student's t-test and Pearson correlation coefficient test were used for the analysis using the R statistical software. No statistically significant differences were observed when comparing the values analyzed by means of the two devices for HRV. Correlation analysis revealed perfect positive correlation (r = 0.99, P < 0.001) between the values in time and frequency domain obtained by the devices. CONCLUSION: On the basis of the results of the present study, we suggest that the calculation of HRV values in the time and frequency domains by RR series obtained from the PC-based sound card is probably as reliable as those obtained by the gold standard Biopac MP36.

Research in occupational heat stress in India: Challenges and opportunities.

Occupational heat stress is a major health burden with several potential negative health and well-being outcomes. It is only in the recent years medical research has addressed this risk factor. The aim of this paper is to present an overview of studies in the area of occupational heat stress and its health impacts. Research in occupational heat stress in developing countries like India is limited because of several challenges and constraints. Few challenges are permission from industries to publish the data, resistance for change from employers and workers, improper record of heat/any occupational disease by the employer or worker, study design, and paucity in number of studies. Proper education and guidelines can help to overcome some of the constraints. Proper and correct guidelines will help in mitigating the effects of excessive heat exposure on the health of workers. The studies in this area are limited, and the association between occupational heat exposure and health impacts is not clearly established. Hence, carefully designed studies are required to examine this association and thereby provide valuable information to protect worker's health.

Cardiovascular autonomic responses to whole body isotonic exercise in normotensive healthy young adult males with parental history of hypertension.

The objective of this study was to assess blood pressure and autonomic activity during rest and recovery in young adult normotensives offsprings of hypertensives. A total of 49 healthy normotensive males with BMI of 18.5-24.9 kg/m2 chosen for the study and classified into two groups based on their parental history of hypertension underwent a sub maximal cycle ergometry exercise test. ECG and heart rate were recorded at baseline, during the exercise test and during recovery period of ten minutes while blood pressure was recorded at baseline and during recovery. Spectral analysis of HRV was performed. The basal systolic blood pressure and the recovery systolic blood pressures at the 1st and 3rd minute of recovery after exercise test were significantly higher in the study group than the control group. The basal LFnu and LF/HF ratio were significantly higher while the basal HFnu was significantly lower in the study group than the control group. A difference in basal systolic blood pressure, a higher LFnu and a lower HFnu found in offspring of hypertensive parents may be an early marker of cardiovascular change in subjects with a genetic predisposition to hypertension.

A simple method of measuring total daily energy expenditure and physical activity level from the heart rate in adult men.

OBJECTIVE: To evaluate a simple method that uses only a heart rate monitor to predict total energy expenditure (TEE) and physical activity level (PAL) from 24 h heart rate (HR) measurements. DESIGN: The simple method involved the determination of the physical activity ratio (PAR) from corresponding heart rate ratios (HRR) (ratio of observed to resting HR), from an individualized calibration curve relating activities with known PAR to the HRR. Several curve fits were evaluated for this curve. The PAL was calculated from minute to minute PAR. The TEE was computed as the product of the PAL and the predicted basal metabolic rate (BMR). The accuracy of the simple method was assessed by within-subject comparisons of the simple method versus the oxygen consumption - HR method and a time and motion study. SETTING: Bangalore City, India. SUBJECTS: In all, 17 healthy male subjects between 18 and 44 years were recruited for the study. INTERVENTIONS: None. RESULTS: The simple method correlated well with both the reference methods when using a calibration curve that involved the fitting of two straight lines at low and high PAR activities, respectively, to the PAR and HRR data. The mean error in TEE, as a product of BMR and PAL, was about 1%, but with limits of agreement between the methods that were about 20% of the TEE. However, the low mean error could have been due to a canceling of errors in the determination of BMR and PAL. CONCLUSIONS: The simple method is a relatively cheap, useful technique for evaluating TEE and PAL in resource-poor situations. It may particularly be of use in epidemiological investigations where population estimates of TEE and PAL are required.

Serum nitrate levels as an index of endothelial function in pre-eclamsia and normal pregnancy.

The study was conducted in St. John's Medical College Hospital and Department of Physiology, with the aim of studying the serum nitrate levels in pre-eclampsia and normal pregnancy. The total number of subjects studied in various groups were 159, control (n = 55), first trimester (n = 13), second trimester normal (n = 42), second trimester pre-eclampsia/PET (n = 5), third trimester normal (n = 32), third trimester pre-eclampsia/PET (n = 12). The serum nitrate was measured by one step enzymatic assay using Nitrate reductase from Aspergillus species. The nitrate levels in the third trimester pre-eclamptic group was found to be significant lower (P = 0.02), as compared to normal subjects, however the renal functions were normal in all the subjects.

The development and validation of a digital peak respiratory pressure monitor and its characteristics in healthy human subjects.

A digital peak respiratory pressure (DPRP) monitor for determining maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) was developed using a pressure transducer and an analog to digital converter. It was calibrated using a mercury manometer. Human studies were conducted in healthy young adults in order to determine within-subject and inter-individual variability, as well as diurnal variations and gender differences in maximal respiratory pressures. The calibration studies for the instrument indicated that the instrument recorded accurate pressures, with little temporal drift. Within-subject variability was generally low while inter-individual variability was higher and significant. Gender differences were similar to those recorded in literature for other racial groups. The DPRP monitor described is inexpensive, accurate and portable, making it ideal for use at the patient's bedside.

The perceptions of first-year medical students on animal and human experiments in physiology.

This study was conducted to ascertain the attitudes of first year medical students to human and animal experimentation, while undergoing a course in Muscle and Nerve experimental Physiology. At the time of administration of the questionnaire, students had been exposed to both human as well as animal experiments. Approximately 81% of the students preferred human experiments (P < 0.05). This preference, however, was related more to the issue of enjoyability rather than the extent to which the experiment contributed to overall understanding and learning. 55% of students identified ethical issues related to laboratory experimentation. Gender and academic performance were not determinants of student's attitude to animal and human experimentation, although ethical insight was. The results suggest that while students recognize the importance and value of animal experiments, they would prefer the introduction of a larger number of human experiments.