Comparing the Efficacy of Paracetamol, Ibuprofen, and a Combination of the Two Drugs in Relieving Pain and Fever in the Pediatric Age Group: A Prospective Observational Study.

Introduction Fever and pain are common afflictions in the pediatric population, prompting the use of paracetamol and ibuprofen as primary treatment options. However, a comprehensive understanding of their comparative efficacy, safety profiles, and potential combined use remains crucial for informed clinical decision-making. In this prospective observational study, we aimed to delve into these aspects, shedding light on the optimal management strategies for fever and pain in pediatric patients. Methodology A total of 108 children were enrolled and categorized into three groups, namely, paracetamol monotherapy, ibuprofen monotherapy, and a combination of both drugs. Axillary temperature monitoring and assessment of pain on the Face, Legs, Activity, Cry, and Controllability (FLACC) scale/Visual Analog Scale (VAS) were employed as critical indicators. Concurrently, associated symptoms encompassing discomfort, activity levels, and appetite were meticulously recorded. To ensure safety, laboratory parameters including serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), serum creatinine, platelet count, and stool for occult blood were closely monitored before and after drug administration. The study duration spanned 48 hours post-initiation of the initial drug dose. Results A total of 108 pediatric cases were included in the study, spanning ages from six months to 18 years. Among them, the majority fell within the age group of six months to five years (n = 77). Participants were categorized based on the duration of fever, with 81 cases having a fever lasting more than 24 hours and 27 cases having a fever lasting less than 24 hours. The majority of cases presented with temperatures ranging from 38°C to 39°C. Comparison of drug efficacy in defervescence within the first four hours revealed that paracetamol alone took significantly longer than ibuprofen monotherapy or the paracetamol and ibuprofen combination (p = 0.026). In terms of the onset of effect, the paracetamol and ibuprofen combination showed comparable efficacy to ibuprofen alone. Regarding the total time without fever in 48 hours, significant differences were observed among the three drug regimens (p = 0.001 by the one-way analysis of variance (ANOVA) test). Paracetamol and ibuprofen were superior to paracetamol alone (p < 0.001) and ibuprofen alone (p = 0.014), while paracetamol alone and ibuprofen alone exhibited similar efficacy (p = 0.197). Based on the laboratory results as well as the clinical profile observed over 48 hours, we confirm safety based on this study. The combination of paracetamol and ibuprofen showed enhanced effectiveness in fever and pain relief. Conclusion This study demonstrates the favourable efficacy of paracetamol, ibuprofen, and their combination in the pediatric population. The combination of paracetamol and ibuprofen showed enhanced effectiveness in fever and pain relief, with minimal adverse effects and no significant derangements in biochemical parameters. This study thus contributes valuable insights to optimize the therapeutic approach to fever and pain in pediatric patients.

Sympathovagal Balance and Body Shape Index in Elite and Amateur Athletes: The Relationship Unraveled.

Background Heart rate variability (HRV) is one piece among a complex network of adaptations existent in athletes that help them gain a better understanding of their own physiology. Sympathovagal balance is one of the spectral components of HRV analysis and is used to assess the frequently changing oscillations of a healthy heart, which can help in gauging the response of cardiac function towards physiological stress during exercise. This index is extensively used in appraising cardiac autonomic modulation. An evaluation of body composition in athletes has become a critical consideration when tracking HRV, as it helps practitioners understand the role of the autonomic nervous system (ANS) in obesity. The body shape index (BSI), which is based on waist circumference (WC), is an anthropometric parameter with decent predictive ability when measuring centripetal obesity. In this regard, the current study is an attempt to unravel the relationship between BSI and sympathovagal balance during exercise performed on two different instruments (treadmill and ergometer) by elite and amateur athletes. Methods It was an observational case-control study that included 30 elite and 120 amateur athletes. Symptom-limited exercise testing was performed by athletes on a motorized treadmill and ergometer in the sports physiology laboratory of a rural medical college in central India. Different anthropometric parameters like BSI and body surface area (BSA) were also recorded. Short-term HRV extracted from electrocardiogram (ECG) recordings was obtained using the Power Lab system and HRV analysis by LabChart software. Results The sympathovagal ratio, i.e., ratio of low frequency (LF) to high frequency (HF) in elite and amateur male populations showed a higher value than that in females, indicating a dominant sympathetic response in the males. There was a significant (p=0.042) positive correlation (r=0.24) between BSI and LF/HF Ratio in amateur females during treadmill exercise, whereas a significant (p=0.049) negative correlation (r=-0.27) was obtained in amateur males during ergometer exercise. Hence, increased weight and BSI were found to be associated with high sympathetic dominance, indicating a sympathovagal imbalance. Conclusion We attempted to explore the interaction between BSI and LF/HF during exercise performed on two different instruments (treadmill and ergometer) by elite and amateur athletes, which can help in testing the response of cardiac function to stress experienced during exercise. The study's uniqueness stems from discovering the relationship between BSI and HRV and how this relationship impacts sports performance. BSI measurement in athletes, both elite and amateur, allows for the assessment and forecasting of potential autonomic activity under exercise-induced stress by linking HRV with BSI.

Examining Body Fat Percentage, Galvanic Skin Response, and Muscle Grip Strength in Female Hypothyroid Patients.

Background The thyroid gland is an indispensable organ exerting control over the activity of multiple organ systems including the autonomic nervous system. This study attempted to monitor the variations in autonomic function parameters such as galvanic skin response (GSR) and muscle grip strength (HGS) in conjunction with changes in body fat percentage (BFP). Methodology This case-control study was conducted among 40 female hypothyroid patients as cases and 40 age-matched female healthy volunteers as controls. Anthropometric data were collected using standard techniques. GSR and HGS were measured using Equivital Sensory Electronic Module and Grip Force Transducer, respectively. Data extraction and analysis were done using the LabChart software. Results The mean age of the 40 female hypothyroid patients was 30.14 ± 5.91 years, whereas the mean age of the female controls was 29.37 ± 6.59 years. The waist circumference of cases was 85.81 ± 10.39 cm while that of controls was 80.90 ± 11.18 cm. The BFP of cases was 35.38% ± 6.74% while that of controls was 31.72% ± 5.63%. The GSR amplitude showed a significant difference between hypothyroid and healthy volunteers with values of 1.34 ± 1.14 µS and 2.40 ± 1.86 µS, respectively. The HGS indices showed no significant difference between the two groups. A statistically negative correlation was noted between BFP and GSR amplitude (-0.32), whereas a positive correlation was noted between BFP and mean handgrip strength (0.31) in hypothyroid patients. Conclusions The changes in BFP and autonomic function through GSR and HGS were evaluated in female hypothyroid patients with respect to healthy females. The interrelationship between anthropometry and autonomic function was also explored in this study. The findings of this study can augment prognosis in patients and ensure timely corrective treatment for improving quality of life.

Exploring the Relationship Between the Indices of Body Composition With Grip Strength Performance and Peak VO2.

Background The importance of measurements of body composition in terms of various indices including Body Mass Index (BMI), Body Surface Area (BSA), Body Size Index (BSI), and Waist to Height ratio (WtHR) in the diagnosis of health risks and mortality outcome analysis has largely been limited to their use relating to determining abdominal obesity. The understanding of the extent of implications of the newer, underutilized indices of body composition is deficient. Peak VO2 (maximal oxygen uptake) majorly serves for the evaluation of the measure of aerobic capacity. Grip strength performance is a simple, primary, objective predictor of overall physical status and muscular and cardiovascular fitness. This study aimed to derive the relationship between a gamut of parameters such as BMI, BSA, WtHR, BSI, grip strength performance and peak VO2 investigated using the latest scientific methodology in a cross-section of the population in a rural tertiary care center. Methodology This study was a descriptive, cross-sectional study carried out in a rural medical college in central India. Sixty participants from the healthcare setting were considered eligible for the study within the age group of 18 to 45 years. Anthropometric assessments like height (in cm), weight (in kg), waist circumference (in cm), and BMI were carried out. BSA, WtHR, and BSI were calculated using the respective formulae. VO2 max (maximal oxygen uptake) recordings were done using the treadmill/ergometer and metabolic module of LabChart software (Bella Vista, New South Wales, Australia). Grip Strength Performance was quantified by measuring the amount of static force with which the hand is able to squeeze a transducer. It was measured using Grip Force Transducer (MLT004 / ST) from AD Instruments (Bella Vista, New South Wales, Australia). Results Upon analysis, a significant negative correlation was obtained between BSI and BMI (r= -0.51, p<0.0001) whereas a significant positive correlation was found between BSA and BMI (r= 0.71, p< 0.0001). A significant correlation was also seen between WtHR and BMI (r= 0.71, p< 0.0001) while a negative significant correlation between peak VO2 and BMI (r= -024,p=0.0425) was deduced. Similarly, a negative correlation was evident between BSA and BMI (r= -0.46, p=0.0002) with a positive correlation between WtHR and BSA (r= 0.30,p=0.0188). Grip strength performance positively correlated with BSA (r= 0.58, p< 0.0001) whereas peak VO2 showed a significant negative correlation with WtHR (r= -026,p=0.043). There was also a positive significant correlation between grip strength performance and peak VO2 (r= 0.37, p=0.0033) Conclusion The study determined the relationships of grip strength performance and peak VO2, with the body composition indices in order to provide an overview of the mortal risks of an individual which might mediate the prognosis. Based on the relative independence of BSI with peak VO2 and grip strength performance, the unification of these parameters can help assess the overall health of an individual.

Divulging the Impetus of Yoga on Cardiorespiratory Fitness and Its Persona in Alleviating Anxiety Experienced by Youth: A Cohort Interventional Study.

BACKGROUND:  Globalization endangers youngsters worldwide with new standards and possibilities. Hereat of being exposed to greater demands and expectations, when it comes to performance review, their life may become more distressed. Yoga with revolutionary methods may assist youngsters in bettering their physical health regarding their maximal oxygen uptake, and also help manage their anxiety. This study ascertains the effect of yoga on youth's anxiety levels and cardio-respiratory fitness. METHODS:  It was a longitudinal interventional study recruiting 99 medical students wherein VO2 max (maximal oxygen uptake) on the treadmill/ergometer exercise and anxiety scores through Spielberger's anxiety scale was assessed at baseline and evaluated after 6 months of a regular yogic regime. The VO2 max was recorded by the metabolic module of Labchart software (Bella Vista, New South Wales, Australia). FINDINGS:  The VO2 max evaluated by incremental exercise to volitional fatigue was found to be 2.64 ± 0.49 L/min in males and 1.51 ± 0.44 L/min in females pre-yoga and 2.81 ± 0.52 L/min in males and 1.69 ± 0.47 L/min in females post yoga. The difference in the endline and baseline VO2 max values of yoga-performing males (t=6.595, p<0.001) and females (t = 2.478, p = 0.017) was found to be significantly higher than non-yoga performers. The METS value obtained in males was 11.96 and in females was 7.68 before yoga. Post-yoga values were 13.44 and 8.37, respectively. The difference in total anxiety scores post-intervention was 34.6 which was statistically significant (t= 4.959, p <0.001). CONCLUSION:  From the viewpoint of a physiologist, higher VO2 max in young adults links to better physical fitness which is the potential outcome of regular yogic practice. As a result of regular yogic practice, initial soaring anxiety levels of subjects culminated in a drastic observable reduction in anxiety, which helped inculcate a judicious acumen in youngsters.

Exploring the Effect of Yoga on Exercise Endurance As Assessed by Cardiorespiratory Efficiency Tests in Exercise Physiology Laboratory: A Pilot Study.

Background Today's world of cut-throat competition is boggling with stress as the most common problem among the modern generation, and reduction in stress demands a radical solution. Yoga comes as a rescuer that focuses on improving one's physical and spiritual well-being. It can increase one's strength and flexibility. Yoga practitioners have asserted the effect of physical exercise involved in it on balancing physical and spiritual health for decades, but only recently has there been a move to substantiate these claims through research. This study aimed at assessing the effect of yogic practice on exercise endurance and physical fitness as assessed by important physical fitness parameters through cardiorespiratory efficiency tests in an Exercise Physiology Laboratory. Methodology A total of 60 Bachelor of Medicine, Bachelor of Surgery (MBBS) students from a rural medical college in central India were recruited for the study. Thirty MBBS students who had undergone yogic training for six months comprised the trained or the case group, and another group of 30 students comprising the untrained group were recruited for the study from different levels of the course within the age group of 17-25 years. Body mass index (BMI) and body surface area (BSA) were calculated. Resting pulse rate and blood pressure, resting respiratory rate, maximal oxygen consumption (VO2 max), physical fitness index (PFI), breath holding time (BHT), and 40 mm Hg endurance test time was measured.  Results The mean PFI (%) in males was 88.82±5.56 and 96.05±7.44, and that in females was 82.06±8.95 and 96.55±6.47 in the control and case groups, respectively. The mean 40 mm Hg endurance test (in seconds) in males was 36.47±8.45 and 48.88±8.64 and in females was 29.79±10.30 and 38.4±10.69 in the control and test groups, respectively. The mean BHT (in seconds) in males was 44.80±14.18 and 58.91±12.35, and that in females was 42.29±15.37 and 54.60±13.36 as in control and case groups, respectively. The VO2 max evaluated by the modified Harvard step test was 2.41±0.58 L/min in control males and 3.6±0.90 L/min in the case group of males, and it was 2.14±0.49 L/min in the control group of females, and 3.76±0.69 L/min in case group of females. Conclusion By studying the dynamics of the various cardiorespiratory responses, we have determined the values of fitness parameters in the case group. It was found that the yoga group had statistically significantly higher VO2 max per minute and better PFI, BHT, and 40 mm Hg endurance values (p<0.05).

Normative Data on Heart Rate Variability Time and Frequency Domain Indices in a Healthy Central Indian Population Undergoing Treadmill Exercise.

Background: Heart rate variability (HRV) is becoming one of the most valuable tools for assessing a healthy heart's complex and constantly changing oscillations. This study was a pioneering attempt to establish normative data on HRV during treadmill exercise for monitoring the cardiovascular health of the central Indian population. Methodology: This was a cross-sectional study in the Sports Physiology Laboratory of the Department of Physiology in a Rural Medical College in central India. One hundred and twenty healthy subjects in the age range 17-40 years were recruited. Short-term HRV (5 min) was extracted from ECG recordings obtained using the Power lab system, AD Instruments, Australia. Results: Time domain indices for males were - Standard deviation of N-N interval (SDNN): 162.61±162.11; Square root of mean squared difference of N-N intervals (RMSSD): 355.79±798.27; the percentage of adjacent NN intervals that differ from each other by more than 50 ms (pNN50): 23.10±27.87. Frequency domain indices in males were- LF power (%)- 535.74±3625.96; HF power (%) - 33.15±24.31, LF nu: 33.12± 16.06; HF nu: 57.22±14.89; LF/HF:0.77±0.74. Time-domain indices for females were SDNN as168.49±130.09; RMSSD: 182.41±154.85; pNN50:32.33±26.59. Frequency domain indices in females were LF power (%)-19.85±6.13; HF power (%) 43.03±16.39, LF nu-30.53±9.88; HF nu -60.95±8.70; LF/HF:0.54±0.27. Conclusion: Baseline normative values for HRV spectral and time-domain analysis have been established for their clinical use in comparing the HRV of a healthy individual to that of a deceased individual or an athlete.

Impact of Spectral Severity of Alcoholism on Visual-Evoked Potentials: A Neuropsychiatric Perspective.

BACKGROUND: The deleterious effects of alcohol on the brain are replete in literature. Only a few neurophysiologic measures can pick up the neuronal dysfunctions, one of them being visual-evoked potential (VEP). A very limited amount of data exists on the progression of neural abnormalities related to the spectral severity of alcoholism. AIM OF THE STUDY: To evaluate the impact of spectral severity of alcoholism through VEP and to understand the emergence of any specific pattern or morphometric abnormalities related to alcohol-induced neuropsychiatric presentations. METHODOLOGY: A total of 90 cases were recruited in addition to 180 age- and sex-matched controls using purposive and random sampling. The Structured Clinical Interview for DSM-IV Axis I Disorders, Clinician Version and Campbell Neuropsychiatric Inventory were used to evaluate alcohol disorders and its neuropsychiatric complications apart from the mandatory consultant-specific clinical evaluations of all the cases. Of 90 cases of alcohol dependence, 15 patients were currently abstinent for >6 months, 15 had alcohol intoxication, 15 had signs of alcohol withdrawal, 15 had physical complications, 15 had psychiatric comorbidity, and 15 had neurological complications such as epilepsy. VEP recordings were taken using an Evoked Potential Recorder (RMS EMG. EP MARK II) where the stimulus configuration consisted of transient pattern-reversal method in which a black and white checkerboard was generated full field. RESULTS: Mean age of cases was 37.71 ± 11.49 years compared to 39.43 ± 10.67 years in controls (range 18-65 years). VEP abnormalities comprising of prolonged latencies (62.5%) with a statistically significant difference (P < 0.001) from the healthy controls was observed in cases of alcohol withdrawal syndrome. Predominant amplitude reduction with normal latency was obtained in 37.5% cases of withdrawal. Severe VEP abnormalities, i.e., both latency delay and amplitude reduction, were found in 75% patients with psychiatric comorbidity, 66.67% patients with neurological complications, i.e., epilepsy, and 33.34% patients with physical complications. An explicit finding of prominent interocular differences was a prominent feature present in 25% of patients with complications.

Atypical waveform morphology in schizophrenia-visual evoked potential as a promising endophenotype.

BACKGROUND: Electrophysiological research has provided measures of dysfunction of visual pathway in schizophrenia through the use of visual evoked potential (VEP) as the neurophysiologic tool. OBJECTIVE: The main objective of this study is to examine the morphology and topography of VEP responses in schizophrenic patients and to explore the potentiality of VEP as an endophenotype. MATERIALS AND METHODS: The study included 20 patients of schizophrenia who were recruited from the outpatient and inpatient department of psychiatry of a tertiary care rural hospital. The patients were assessed by tools such as Positive and Negative Symptoms Assessment Scale and Clinical Global Impression Scale for Severity. Transient Pattern Reversal VEP recordings were taken using an Evoked Potential Recorder (RMS EMG EP MARK II), and it was a cross-sectional study. RESULTS: The mean age of patients was 45.95 ± 10.14 years in the range of 35-60 years. Qualitative analysis of VEP waveforms in people with schizophrenia was performed. Abnormal waveform morphology was observed in 14/20 (70%) of the study population and all of them were the chronic and severe cases. Six out of 15 (40%) showed lack of differentiation of the evoked complex so that the three waves (negative-positive-negative [NPN] complex) could not be identified. In 5 of 15 (33.33%) VEP records, a distinct altered waveform with extinguished second negative component of NPN complex was obtained. CONCLUSION: Qualitative morphometric findings of this study in terms of pattern-reversal VEP waveform abnormalities emerged as a tool to provide evidence of relationship for emerging as first potential biomarker for diagnosing schizophrenia.

A Comprehensive Review on Methodologies Employed for Visual Evoked Potentials.

Visual information is fundamental to how we appreciate our environment and interact with others. The visual evoked potential (VEP) is among those evoked potentials that are the bioelectric signals generated in the striate and extrastriate cortex when the retina is stimulated with light which can be recorded from the scalp electrodes. In the current paper, we provide an overview of the various modalities, techniques, and methodologies which have been employed for visual evoked potentials over the years. In the first part of the paper, we cast a cursory glance on the historical aspect of evoked potentials. Then the growing clinical significance and advantages of VEPs in clinical disorders have been briefly described, followed by the discussion on the earlier and currently available methods for VEPs based on the studies in the past and recent times. Next, we mention the standards and protocols laid down by the authorized agencies. We then summarize the recently developed techniques for VEP. In the concluding section, we lay down prospective research directives related to fundamental and applied aspects of VEPs as well as offering perspectives for further research to stimulate inquiry into the role of visual evoked potentials in visual processing impairment related disorders.

Cardiac hemodynamic profile and its correlates by Impedance plethysmography in normal individuals of Central India.

Evaluation of hemodynamic profile by impedance plethysmography (IPG) provides functional expression of cardiovascular performance with efficacy of treatment. Objective of this study was to establish normative hemodynamic parameters by IPG. In this cross-sectional study hemodynamic parameters including cardiac output (CO), Stroke volume (SV), left ventricular ejection time (LVET), impedance (Zo) Cardiac index (CI) and Stroke index (SI) of 50 normal individuals in mean age 38.9±15.2 years were evaluated. Mean CO and CI were 4.9±0.8L/min and 3.3±0.7 L/min/m2 respectively. A negative linear co-relation of CI with increasing age and body fat mass was observed. Mean LVET was 336±33ms with a significant positive linear correlation (r = 0.46) with advancing age and body fat mass while a negative linear correlation with BSA. To conclude preliminary normative data of cardiac parameters using IPG, in subjects of central India of different age groups has been presented.

Teratogenic effects of insulin: an experimental study on developing chick embryo.

OBJECTIVE: The objective was to observe the effect of insulin on chick embryos with reference to their growth and developmental defects. MATERIALS AND METHODS: An experimental study was performed to assess any abnormal growth pattern caused by insulin. For this, two batches of 100 fertilized eggs were utilized. One batch of 50 was used as a control group and other as an experimental group. Insulin (2 IU) was injected on day 2 of incubation. Chicken eggs were dissected out on day 19 of incubation and were carefully observed for any congenital abnormalities. The embryos thus dissected out were subjected to measurement of crown-rump length (CRL), changes in weight of egg, volume of embryos were compared in two groups. The embryos were also examined for any congenital anomalies. RESULTS: No major malformations were observed. Decrease in weight and CRLs was lower in the experimental group as compared to their control counterparts. Values for volume of the embryo were similar in two groups. CONCLUSION: No obvious teratogenic effects are observed with insulin in the dose use for the study.

Influence of visual angle on pattern reversal visual evoked potentials.

PURPOSE: The aim of this study was to find whether the visual evoked potential (VEP) latencies and amplitude are altered with different visual angles in healthy adult volunteers or not and to determine the visual angle which is the optimum and most appropriate among a wide range of check sizes for the reliable interpretation of pattern reversal VEPs (PRVEPs). MATERIALS AND METHODS: The present study was conducted on 40 healthy volunteers. The subjects were divided into two groups. One group consisted of 20 individuals (nine males and 11 females) in the age range of 25-57 years and they were exposed to checks subtending a visual angle of 90, 120, and 180 minutes of arc. Another group comprised of 20 individuals (10 males and 10 females) in the age range of 36-60 years and they were subjected to checks subtending a visual angle of 15, 30, and 120 minutes of arc. The stimulus configuration comprised of the transient pattern reversal method in which a black and white checker board is generated (full field) on a VEP Monitor by an Evoked Potential Recorder (RMS EMG. EPMARK II). The statistical analysis was done by One Way Analysis of Variance (ANOVA) using EPI INFO 6. RESULTS: In Group I, the maximum (max.) P100 latency of 98.8 ± 4.7 and the max. P100 amplitude of 10.05 ± 3.1 µV was obtained with checks of 90 minutes. In Group II, the max. P100 latency of 105.19 ± 4.75 msec as well as the max. P100 amplitude of 8.23 ± 3.30 µV was obtained with 15 minutes. The min. P100 latency in both the groups was obtained with checks of 120 minutes while the min. P100 amplitude was obtained with 180 minutes. A statistically significant difference was derived between means of P100 latency for 15 and 30 minutes with reference to its value for 120 minutes and between the mean value of P100 amplitude for 120 minutes and that of 90 and 180 minutes. CONCLUSION: Altering the size of stimulus (visual angle) has an effect on the PRVEP parameters. Our study found that the 120 is the appropriate (and optimal) check size that can be used for accurate interpretation of PRVEPs. This will help in better assessment of the optic nerve function and integrity of anterior visual pathways.

Correlation of pattern reversal visual evoked potential parameters with the pattern standard deviation in primary open angle glaucoma.

AIM: To evaluate whether glaucomatous visual field defect particularly the pattern standard deviation (PSD) of Humphrey visual field could be associated with visual evoked potential (VEP) parameters of patients having primary open angle glaucoma (POAG). METHODS: Visual field by Humphrey perimetry and simultaneous recordings of pattern reversal visual evoked potential (PRVEP) were assessed in 100 patients with POAG. The stimulus configuration for VEP recordings consisted of the transient pattern reversal method in which a black and white checker board pattern was generated (full field) and displayed on VEP monitor (colour 14″) by an electronic pattern regenerator inbuilt in an evoked potential recorder (RMS EMG EP MARK II). RESULTS: The results of our study indicate that there is a highly significant (P<0.001) negative correlation of P100 amplitude and a statistically significant (P<0.05) positive correlation of N70 latency, P100 latency and N155 latency with the PSD of Humphrey visual field in the subjects of POAG in various age groups as evaluated by Student's t-test. CONCLUSION: Prolongation of VEP latencies were mirrored by a corresponding increase of PSD values. Conversely, as PSD increases the magnitude of VEP excursions were found to be diminished.

Significance of Visual Evoked Potentials in the Assessment of Visual Field Defects in Primary Open-Angle Glaucoma: A Review.

Visual evoked potentials is an important visual electrophysiological tool which has been used for the evaluation of visual field defects in primary open-angle glaucoma and is an appropriate objective measure of optic nerve function. Significant correlations between the magnitude of the VEP parameters and MD of Humphrey static perimetry suggest that the impaired visual cortical responses observed in glaucoma patients can be revealed by both electrophysiological and psychophysical methods. In addition, the severity of global glaucomatous damage evidenced by reduction in MD could depend on the delay in neural conduction from retina to the visual cortex as revealed by the significant correlation between VEP latencies and MD which also supports the validity of the VEP testing in progression of glaucoma.

Association of Height With Pattern Reversal Visual Evoked Potentials.

PURPOSE: This study was conducted to investigate whether pattern reversal visual evoked potential parameters in a large sample of healthy subjects are influenced by height of the subjects. DESIGN: It was an institutional, cross-sectional study. METHODS: Pattern reversal visual evoked potential (PRVEP) recordings from 400 eyes from 200 normal subjects were performed in the Neurophysiology unit of the Department of Physiology in accordance to the standardized methodology and montages were kept as per 10-20 International System of electroencephalogram electrode placements. VEP latencies, duration and amplitude were measured in all subjects. The correlation of all the electrophysiological parameters with height was evaluated by Pearson's correlation co-efficient (r) and its statistical significance was evaluated. RESULTS: On correlating mean height with mean VEP parameters of both eyes in the subjects it was found that there is a positive correlation of P100 latency and N155 latency in the subjects and a highly significant negative correlation of P100 amplitude with height in the subjects of various age groups. N70 latency was found to be significantly positively correlated with height whereas P100 Duration showed a non-significant negative correlation with height of the subjects. CONCLUSION: Our findings suggest that VEP latencies, duration and amplitude are influenced by the height of the individual. The positive correlation between VEP latencies and increasing height may all reflect the increase in length between the optic nerve head and the visual processing areas-the striate and the extra striate cortex which are the main generators of the various PRVEP waveforms.

Association of pattern reversal VEP parameters with the mean defect of Humphrey visual field in patients of primary open angle glaucoma.

Glaucoma is a chronic, progressive bilateral optic neuropathy which disturbs the structural or functional integrity of the optic nerve that causes characteristic atrophic changes in it, which leads to specific visual field defects over time with loss of visual function. Primary open angle glaucoma (POAG) is the most common form of glaucoma in India and is fast emerging as a major cause of bilateral blindness. This rural hospital based study was conducted to evaluate whether glaucomatous visual field defects particularly the mean defect of Humphrey visual field could be related to VEP parameters of patients having POAG. Visual field by Humphrey perimeter and simultaneous recordings of pattern reversal visual evoked potential (PRVEP) were assessed in 100 patients with POAG. There was a significant (P < 0.05) negative correlation of P100 latency, N155 latency and P100 duration and a highly significant (P < 0.001) positive correlation of P100 amplitude with mean deviation (index of global visual field damage, MD) of Humphrey visual field in the subjects of POAG in various age groups. N70 latency showed a non-significant positive correlation with MD. The VEP changes observed by us in POAG patients were consistent with the progressing mean defect quantitatively. Therefore, it can be concluded that the VEP parameters can be useful quantitative indices in the evaluation of glaucomatous visual function damage.

Modes of Degradation and Impurity Characterization in rhPTH (1-34) during Stability Studies.

During storage of recombinant human parathyroid hormone (rhPTH) (amino acid residues 1-34) at 25 ± 2 °C, several impurities were obtained, which were detected by the tricine sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and reversed-phase high-performance liquid chromatography (RP-HPLC) methods. To characterize the impurities generated, forceful chemical oxidation and deamidation was done. The oxidized positions were characterized by cyanogen bromide (CNBr) cleavage followed by liquid chromatography/mass spectrometry (LCMS) and further confirmed through N-terminal sequencing. Three oxidized variants were observed: sulfoxide of Met8 and Met18 and a variant comprising sulfoxide forms of both the methionine residues. LCMS results confirmed the presence of deamidated (+1 Da) and succinimide (-17 Da) variants. The low molecular weight impurities observed by tricine SDS-PAGE was confirmed to be peptide fragments by N-terminal sequencing and LCMS, resulting from cleavage at the C-terminal of asparagine (Asn)16, Asn33, and Asp30. Studies showed that rhPTH (1-34) undergoes oxidation, deamidation, and peptide bond cleavage during storage at pH 4.0 in acetate buffer. LAY ABSTRACT: Unlike currently licensed therapies to manage osteoporosis, parathyroid hormone (PTH) and its analogs represent a new class of anabolic agents, which act primarily to inhibit bone resorption and remodeling. The hormone's recombinant form is a bioactive peptide, 1-34 residues, which is inherently very unstable. Prior understanding of the molecular degradation pathway will help in development of a process that will yield a better product with respect to its quality and stability. The current work focuses on detailed characterization of the product-related impurities generated during storage of recombinant human PTH. The study depicted the various routes through which the molecule can degrade during its shelf life. Through a combination of forced degradation and accelerated study, it was established that the impurities were generated owing to oxidation, deamidation, and peptide bond cleavage of/at various amino acid residues. Until this study, it was presumed that oxidation is the primary route of degradation in PTH and most of the published reports were on native (1-84) forms of the hormone. The present research confirms that the recombinant hormone (1-34) degraded not only because of oxidation but that deamidation and peptide bond cleavage are also prominent modes of degradation. Therefore, owing to the unstable nature of the molecule it is suggested that stringent conditions should be maintained during manufacturing to obtain a stable molecule with fewer impurities.