Functional status of auditory pathways in children with borderline intellectual functioning : Evoked potential study.

The present study was undertaken to determine whether impairment of sensory conduction in the auditory pathway is one of the contributory factors of performance in children with borderline intelligence. The study was conducted on children having borderline intelligence (IQ 71-84). The functional integrity of the central auditory pathway was assessed using Auditory Evoked Responses i.e. Auditory Brainstem response (ABR), Mid Latency Response (MLR) and Slow Vertex Response (SVR). The recordings were done using a computerized evoked potential recorder by 10–20 electrode placement system. There was no significant difference in the absolute peak latencies, the interpeak latencies and amplitude of ABR in the subjects as compared to controls. There was prolongation of the latency of MLR and SVR waves in subjects though not statistically significant indicating no conduction abnormality in the auditory pathway of the study subjects. Electrophysiological methods reveal underlying immaturity or abnormal brainstem timing and may serve as reliable tool in individuals with learning difficulties.

Oxidative status in workers engaged in recycling of plastic: Occupational hazard.

Recycling plastic industry is on rise. Plastic waste in environment is a pollutant so recycling of it can save environment and is economical too. However its recycling is associated with harmful effects on workers engaged in it. The present study was designed to elucidate the role of free radicals and cytochrome c in pathogenesis of polypropylene associated diseases. Thirty workers from plastic recycling factory occupationally exposed to polypropylene between the age of 18-40 years and working for atleast 8 hours a day for more than a year but less than 10 years were selected for the study. A trend in increase of FRAP and decrease of MDA was observed but they could not reach the level of significance. The level of serum cytochrome c, which is an indirect marker of oxidative stress, was also detectable in only two subjects. Since the number of subjects in the study was less, the result needs to be confirmed on larger number. More over cause of pulmonary dysfunction and carcinomas in these workers needs to be investigated.

Autonomic reactivity to cold pressor test in prehypertensive and hypertensive medical students.

Autonomic reactivity to stress has been hypothesized to be a marker for subsequent neurogenic hypertension. Medical training is highly stressful particularly for those who are beginning their medical education. The present study was undertaken to study the autonomic reactivity to cold pressor test in prehypertensive and hypertensive undergraduate medical students. One hundred and seventeen undergraduate medical students between 17-21 years of age got examined for blood pressure and stress level. Twelve Hypertensives and eight prehypertensives selected from the above subjects and twenty normotensives underwent cold pressure test (CPT) to assess autonomic reactivity to laboratory induced stress. 10.25% of the subjects were found to be hypertensive and 6.83% pre hypertensive. On the stress scale 53% had mild stress, 7% showed moderate stress while none had stress as a major problem. There was no correlation between BP and stress score. On CPT, BP increased significantly in all the three groups (hypertensive, prehypertensive and normotensive) but came back to basal levels within 5 minutes indicating normal autonomic response. Rise of BP was higher in hypertensive group as compared to normotensive group. The rise of diastolic and mean BP during CPT was significantly higher in subjects having family history of hypertension. Forty percent of normotensive subjects had more than 20 mm Hg rise in systolic BP on CPT. Adolescents must be routinely screened to detect asymptomatic hypertension. The CPT may identify individuals with an occult physiological abnormality that predisposes them to hypertension in their later life.

Pulmonary functions in plastic factory workers: A preliminary study.

Exposure to long term air pollution in the work environment may result in decreased lung functions and various other health problems. A significant occupational hazard to lung functions is experienced by plastic factory workers. The present study is planned to assess the pulmonary functions of workers in the plastic factory where recycling of pastic material was done. These workers were constantly exposed to fumes of various chemicals throughout the day. Thirty one workers of plastic factory were assessed for their pulmonary functions. Parameters were compared with 31 age and sex matched controls not exposed to the same environment. The pulmonary function tests were done using Sibelmed Datospir 120 B portable spirometer. A significant decrease in most of the flow rates (MEF 25%, MEF 50%, MEF 75% and FEF 25-75%) and most of the lung volumes and capacities (FVC, FEV1, VC, TV, ERV, MVV) were observed in the workers. Smoking and duration of exposure were not affecting the lung functions as the non smokers also showed a similar decrement in pulmonary functions. Similarly the workers working for less than 5 years also had decrement in pulmonary functions indicating that their lungs are being affected even if they have worked for one year. Exposure to the organic dust in the work environment should be controlled by adequate engineering measures, complemented by effective personal respiratory protection.

Visual Evoked Potential in Attention Deficit/ Hyperactivity Disorder.

Objectives: Attention Deficit/Hyperactivity Disorder (AD/HD) is one of the childhood disorder characterized by lack of sustained attention, hyperactivity and impulsivity. Children with AD/HD have functional impairment occurring at multiple levels. Sensory neural processing of visual information can be one of the contributory factors. The present study was undertaken to examine the integrity and function of visual pathway by means of Visual Evoked Potential (VEP). Method: Twenty AD/HD children and twenty controls were taken for the study and Pattern reversal Visual Evoked Potential was recorded on computerized evoked potential recorder using 10-20 system of electrode placement. The statistical analysis for the comparison between controls and AD/HD children was done using unpaired Student’s t test. Results: The latencies of N75, P100 and N145 were increased but could not reach the level of significance. Conclusion: Our finding indicates that the sensory processing is not involved in children with AD/HD alone without any other disorders like Reading Disability, Learning disability etc.

Sensory, cognitive and motor assessment of children with poor academic performance: An auditory evoked potential study.

The present study aims to evaluate the auditory sensory process in the brainstem, thalamocortical and cortical areas by using auditory evoked potentials [auditory brainstem response (ABR), mid latency response (MLR) and slow vertex response (SVR)], cognitive functions by P300 and motor response by reaction time in children with poor academic performance. Thirty children between 6–12 years of age were selected as subjects on the basis of poor academic school records. While thirty children with good academic performance served as controls. The recordings were done using a computerized evoked potential recorder by 10–20 electrode placement system. There was no difference in the anthropometric parameters and IQ of the two groups. There was a significant increase in latency of waves II, III, IV and V, and Inter-peak latency I-V of ABR in poor performer females. All the component waves of MLR and SVR showed increased latency in the subjects but could not reach the level of significance. There was a significant increase in latencies of P300 at Cz and Pz electrode positions with no change in amplitude in poor performer females. The reaction time was also increased in the poor performer females as compared to the controls. The latencies of all the waves of ABR, P300 and reaction time are also increased in male poor performers as compared to male controls but could not reach the level of significance. The conduction of impulses is slower in pontine and midbrain auditory pathway along with inefficient cortical processing of task relevant stimuli and motor response in female children having poor academic performance.

Birth weight and lung functions in male adolescents.

The aim of this comparative retrospective cohort study was to examine the associations between birth weight and lung function in cohort of 70 adolescent male children aged 12–16 years. The subjects, born in nursing homes located in vicinity of the institution having their complete birth records were traced. They were male children between ages of 12– 16 years. Lung function parameters were measured using a portable spirometer DATOSPIR 120 B. The corrected mean difference (95% confidence interval) in forced vital capacity (FVC) was –0.19 ml (–0.55 to 0.16) this was significantly lower in low birth weight group (LBW) as compared to normal birth weight children. All other lung function parameters were not significantly different in the two groups. We did not find a significant association between birth weight at term and lung function parameters in the adolescent age group. While mean FVC which was found to be lower in LBW group in our study might be due to programming in infancy rather than intrauterine life. Our results did not support Barker Hypothesis according to which adverse influences during intrauterine life result in increased disease risk in ‘adulthood.

Acute effects of formalin on pulmonary functions in gross anatomy laboratory.

Formaldehyde is a common indoor pollutant with irritant properties. The present study was undertaken in first year medical students to study the acute effects of it on their first exposure in gross anatomy laboratory. Twenty randomly selected subjects aged between 18 to 20 years and non smokers had undergone pulmonary function testing thrice. First being baseline values then immediately after their first dissection class (2 hrs.) and lastly 24 hrs after their first exposure. All the tests were performed on Siblemed 120 B portable spirometer with inbuilt computer programme under standard laboratory conditions. It was observed that FVC decreased in subjects immediately after their first exposure but reverted back to normal within 24 hrs. While all other lung function parameters remained unchanged, indicating some mild transient bronchoconstriction on acute exposure to formalin. The study needs to be extended with larger number of subjects.

Effect of paternal smoking on the pulmonary functions of adolescent males.

Objective : The present study was conducted to evaluate the effect of paternal smoking on the respiratory function of adolescents. Study method : The study group comprised thirty healthy males between the ages of 12–18 years whose fathers were smokers (Group 1). They were compared with age and sex matched thirty active smoker males (Group 2). The control group comprised age and sex matched thirty males who were neither active nor passive smokers (Group 3). Pulmonary function was assessed using Sibelmed Datospir120B spirometer in a closed room. Results : FEV1/FVC ratio and FEF25%–75% (forced expiratory flow at 25%–75% of vital capacity) were significantly lower in the subjects exposed to paternal smoking as compared to non-smokers. Vital capacity & expiratory reserve volume were significantly lower in active smokers as compared to non-smokers. Conclusions : Our findings suggest a significant reduction in indices of lung functions of adolescents exposed to paternal smoke.

Pulmonary functions in petrol pump workers: a preliminary study.

Occupational exposures to petrol/diesel vapors have been shown to affect functioning of different systems of the body. The present study was planned to assess the pulmonary functions in petrol pump workers (filling attendants) who are continuously exposed to petrol/diesel vapors during duty hours. Thirty healthy non-smoker males working in petrol pump for more than one year formed the study group, while thirty healthy non-smoker males from hospital staff served as control group. The pulmonary functions were assessed using computerized spirometer. The FVC and FEV1 were decreased in the study group while their ratio did not differ much. Both the inspiratory and expiratory flow rates were also decreased in the study group. These findings point towards adverse effects of petrol/diesel fumes mainly on lower airways with restrictive pattern of disease.

Pulmonary functions in air conditioner users.

Air conditioning may affect human health since it has profound effect on our environment, than just lowering temperature. The present study was planned to assess the effect of air conditioners (AC) on pulmonary functions in young healthy non-smoker males. The study group comprised of ten subjects who were using AC's in their cars for at least 1 hr daily since last 6 months. While ten subjects who did not use AC at all served as controls. The pulmonary functions were assessed using PK Morgan 232 spirometer in a closed room. The peak expiratory flow rate (PEFR) and Forced expiratory flow between 25-75% of vital capacity (FEF25-75) were significantly reduced in subjects using car AC's. Inspiratory flow rates also showed a trend towards decline in AC users but could not reach the level of significance. The lung volumes and capacities were not significantly different in the two groups except for forced expiratory volume in 0.5 sec (FEV 0.5 sec), which also decreased in AC users. The airway resistance and lung compliance did not show significant change. In the presence of normal FEV1, reduced FEF25-75% which is the flow rate over the middle half of vital capacity, is an evidence of mild airflow limitation. The result is suggestive of predisposition of AC users towards respiratory disorders in form of mild airflow restriction.

Differential effects of exogenous estrogen versus a estrogen-progesterone combination on auditory evoked potentials in menopausal women.

The study was undertaken to determine the differential effects of estrogen and progestin on auditory evoked responses in postmenopausal women receiving hormone replacement therapy (HRT). Forty-seven women between 45 and 70 years of age attending menopause and HRT clinic were divided into two groups. Group I included 32 women who attained natural menopause and receiving combined estrogen progestin therapy. While group II included 15 surgically menopausal women receiving only estrogen. Evoked potentials were recorded in form of auditory brainstem response (ABR), middle latency response (MLR) & slow vertex response (SVR). There was improvement of conduction in auditory pathways at the level of brainstem and thalamocortical projections as indicated by the decrease in latencies of most of the waves of ABR and/MLR after 6 months of HRT in both the groups. The conduction in association areas, as indicated by SVR, did not show a significant change. The intergroup comparison after therapy revealed a decrease in latency of wave V and I-V interpeak latency in group II indicating that only estrogen users are benefited more. Thus HRT facilitates the process of sensory conduction, which may form one of the mechanisms of improved neuropsychological functions in menopausal women on HRT. The addition of progestin to estrogen does not have a negative or potentiating effect on it.

Introducing problem-based learning in physiology in the conventional Indian medical curriculum.

BACKGROUND: Problem-based learning (PBL) is a widely acclaimed student-centred learning method. However, there are few reports of its use in the traditional lecture-practical-tutorial model of learning. We used PBL for teaching one module of Physiology to first-year medical undergraduate students who had no prior exposure to PBL. METHODS: One hundred first-year medical undergraduates enrolled in a medical college, which follows the traditional teaching-learning methods, participated in the exercise. The scheduled classes on 'Physiology of the thyroid gland' were converted into a PBL block to be covered over a week. An orientation of the teachers and students to PBL was done, clinical cases selected and tutor guides prepared before the actual PBL week. During the PBL week, students were exposed to small group discussions and Interactive resource sessions, and were given time for self-study. The PBL week concluded with a review session and evaluation of the PBL block using questionnaires. RESULTS: A comparison of the pre- and post-PBL questionnaire showed a clear preference for PBL over the conventional curriculum for the interactive resource sessions and group discussions. Both students and teachers found PBL rewarding. CONCLUSION: Implementation of PBL is feasible even in a traditional set-up despite limited resources, rigid time schedules and little interaction among various disciplines. We hope our experience would encourage other teachers to introduce appropriately modified PBL in their ongoing curriculum.

Auditory evoked responses in postmenopausal women on hormone replacement therapy.

The effect of hormone replacement therapy (HRT) was studied in 32 postmenopausal women on their auditory Evoked Potentials i.e. auditory brainstem response (ABR), Middle latency response (MLR) & slow vertex response (SVR). Recordings were done on computerized evoked potential recorder using 10/20 system of electrode placement and standard click stimuli. A significant improvement in neural transmission was observed as was evidenced by decrease in the ABR wave latencies I, III, IV & V and interpeak latency III-V and I-V after 6 months of HRT. A similar significant decrease was observed in MLR wave latencies of Po, Na & Pa. The SVR wave latencies although found to be decreased after HRT, could not reach the level of statistical significance. There was a significant inverse correlation obtained between latencies of wave I in ABR, Po in MLR and serum estradiol. The results indicate the effect of sex hormone in improving transmission in auditory pathway from periphery through brainstem, thalamus upto cortex. However slow vertex responses indicate that auditory association areas are not much affected. This might have bearing on improvement of neuropsychological functions in postmenopausal women on HRT.