Biomedical subjects

O P Tandon

Publications and source records attributed to O P Tandon.

At least 19 recordsLinked to original sources

PubMed2003

Effect of iron on growth in iron deficient anemic school going children.

Iron deficiency anemia (IDA) in children has been associated with retardation in growth and the cognitive development. In the ongoing study on the effects of IDA in school going children, the effects on anthropometric parameters such as height (Ht), Weight (Wt), head circumference (HC), body mass index (BMI) and the mid arm circumference (MAC) were studied along with the hematological parameters such as hemoglobin (Hb), hematocrit (Hct), MCV, MCH, serum iron (SI), total iron binding capacity (TIBC) and % saturation. The pre-supplementation values of all these parameters were taken in anemic and control groups of girls and boys. After deworming all the children with albendazole (400 mg), the anemic group was put on iron supplementation (Ferrous iron 3-4 mg/kg body weight/day) along with vitamin C (100 mg OD) and the control children were given vitamin C (100 mg OD), for 90 days. Pre-supplementation values of IDA children were significantly lower for MAC and HC in girls and for Ht and MAC in boys, when compared to the control group. After the therapy both the groups of girls showed improvement in the hematological parameters though it was greater in the anemic girls. Ht and Wt of both groups also improved significantly but the anemic girls showed increase in BMI also. Both the control and anemic boys showed gain in weight. Post therapy, improvement in hematological parameters for both the anemic girls and boys were greater than their respective control groups. The MAC value for anemic girls were in the control range but those of anemic boys remained lesser than the control boys. So, it can be concluded from the present study that the IDA children lagged behind the control children in terms of anthropometric parameters and they benefited relatively more in terms of anthropometric improvement and hematological improvement after iron supplementation.

Anemia, Iron-Deficiency↗

PubMed2003

Auditory evoked responses in gestational diabetics.

Electrophysiological correlates of sensory function in diabetic pregnancy have not been documented. Present study reports changes in Auditory evoked responses (AER) in gestational diabetics when compared with normal pregnant controls. Human AER are generally classified into early Auditory brainstem responses (AER), Mid latency responses (MLR) and late Slow vertex responses (SVR). These potentials were recorded in 20 women with diabetic pregnancy using Ag/AgCl electrodes from Cz-A1 and Cz-A2 position on MEB 5200 Neuropack II ... plus (Nihon Kohden, Japan) Evoked Potential Recorder. The evoked potentials in gestational diabetics were compared with 20 age matched normal pregnant women using Student's t-test. Absolute latencies of waves I to V, Inter peak latencies I-III and I-V of ABR were significantly increased whereas amplitude of wave V decreased in diabetic pregnant women. No significant change in latency of any component of MLR was observed between the two groups whereas significant prolongation of latencies of all components of SVR was observed in diabetic pregnant women as compared to normal control group. These findings indicate prolongation of both peripheral transmission time (PTT) and central transmission time (CTT) in diabetic pregnant females. Prolongation of latencies of SVR components in this study implicates cortex in the central diabetic neuropathy in women with gestational diabetes.

Adolescent↗

PubMed2002

Event related evoked potentials in dementia: role of vitamin E.

Dementia is a common cognitive syndrome reflecting a wide spread chronic progressive disease as an extension to normal aging process. Oxidative stress has been implicated in dementia and antioxidants have become attractive therapeutic agents. Among the antioxidants vitamin E is the most potent in the treatment of dementia. Study was conducted in 20 patients suffering from dementia in the age group of 66-74 and in 20 age and sex matched controls. Latency of the P3 component of event related evoked potential (ERP) showed an increase from 338.65 +/- 42.22 msec in control group to 348.9 +/- 46.38 msec in patients of dementia. In control group P3 latency decreased from 338.65 +/- 42.22 msec to 331.6 +/- 38.75 msec after Vitamin E therapy. In patients of dementia latency decreased significantly from 348.9 +/- 46.38 msec to 324.62 +/- 44.25 msec after vitamin therapy for one month. P3 amplitude in controls and demented was 7.2 +/- 3.62 mu v and 7.07 +/- 3.73 mu v respectively. After vitamin E therapy a statistically significant increase in amplitude (P < 0.05) was observed in controls (9.34 +/- 5.04 mu v) and in patients of dementia (9.58 +/- 5.24 mu v). The study suggests that the latency and amplitude of P3 were not significantly different in control and dementia patients, while vitamin E supplementation (oral 800 mg per day for 30 days) decreased the latency and increased the P3 amplitude in both the control and dementia patients. Our study further supports that Vitamin E supplementation, because of its antioxidant property might be decreasing oxidative stress, which may lead to improvement in cognitive pool of generator neurons of P3.

Aged↗

PubMed2002

Effect of Yoga asanas on nerve conduction in type 2 diabetes.

Twenty Type 2 diabetic subjects between the age group of 30-60 years were studied to see the effect of 40 days of Yoga asanas on the nerve conduction velocity. The duration of diabetes ranged from 0-10 years. Subject suffering from cardiac, renal and proliferative retinal complications were excluded from the study Yoga asanas included Suryanamskar. Tadasan, Konasan, Padmasan Pranayam, Paschimottansan Ardhmatsyendrasan, Shavasan, Pavanmukthasan, Sarpasan and Shavasan. Subjects were called to the cardio-respiratory laboratory in the morning time and were given training by the Yoga expert. The Yoga exercises were performed for 30-40 minutes every day for 40 days in the above sequence. The subjects were prescribed certain medicines and diet. The basal blood glucose, nerve conduction velocity of the median nerve was measured and repeated after 40 days of Yogic regime. Another group of 20 Type 2 diabetes subjects of comparable age and severity, called the control group, were kept on prescribed medication and light physical exercises like walking. Their basal & post 40 days parameters were recorded for comparison. Right hand and left hand median nerve conduction velocity increased from 52.81 +/- 1.1 m/sec to 53.87 +/- 1.1 m/sec and 52.46 +/- 1.0 to 54.75 +/- 1/1 m/sec respectively. Control group nerve function parameters deteriorated over the period of study, indicating that diabetes is a slowly progressive disease involving the nerves. Yoga asanas have a beneficial effect on glycaemic control and improve nerve function in mild to moderate Type 2 diabetes with sub-clinical neuropathy.

Adult↗

PubMed2002

Study of yoga asanas in assessment of pulmonary function in NIDDM patients.

Certain yoga asanas if practiced regularly are known to have beneficial effects on human body. These yoga practices might be interacting with various, somato-neuro-endocrine mechanisms to have therapeutic effects. The present study done in twenty four NIDDM patients of 30 to 60 year old, provides metabolic and clinical evidence of improvement in glycaemic control and pulmonary functions. These middle-aged subjects were type II diabetics on antihyperglycaemic and dietary regimen. Their baseline fasting and postprandial blood glucose and glycosylated Hb were monitored along with pulmonary function studies. The expert gave these patients training in yoga asanas and were pursed 30-40 min/day for 40 days under guidance. These asanas consisted of 13 well known postures, done in a sequence. After 40 days of yoga asanas regimen, the parameters were repeated. The results indicate that there was significant decrease in fasting blood glucose levels (basal 190.08 +/- 90.8 in mg/dl to 141.5 +/- 79.8 in mg/dl). The postprandial blood glucose levels also decreased (276.54 +/- 101.0 in mg/dl to 201.75 +/- 104.1 in mg/dl), glycosylated hemoglobin showed a decrease (9.03 +/- 1.4% to 7.83 +/- 2.6%). The FEV1, FVC, PEFR, MVV increased significantly (1.81 +/- 0.4 lt to 2.08 +/- 0.4 lt, 2.20 +/- 0.6 lt to 2.37 +/- 0.5 lt, 3.30 +/- 1.0 lt/s to 4.43 +/- 1.4 lt/s and 64.59 +/- 25.7 lt min to 76.28 +/- 28.1 lt/min respectively). FEV1/FVC% improved (85 +/- 0.2% to 89 +/- 0.1%). These findings suggest that better glycaemic control and pulmonary functions can be obtained in NIDDM cases with yoga asanas and pranayama. The exact mechanism as to how these postures and controlled breathing, interact with somato-neuro-endocrine mechanism affecting metabolic and pulmonary functions remains to be worked out.

Adult↗

PubMed2002

Effect of partial ileal bypass on the lipid profile in the hyperlipedemic rabbits.

The hypocholesterolemic effect of partial ideal bypass was studied in two groups of healthy albino rabbits. Both groups of rabbits were made hypercholesterolemic by feeding them cholesterol suspended in groundnut oil (1 ml/kg bw) at a dose of 100 ml/kg bw/day for one week. Group I rabbits were subjected to partial ileal bypass and group II rabbits were sham operated. Weekly estimation of serum lipid profiles were done for four more weeks while continuing cholesterol feed. After end of 5th week, it was found that partial ileal bypass not only prevented but also brought down its level from 132.8 mg% to 44.8 + 2.24 mg%, as compared to sham operates group where cholesterol level was 279 + 5.84 mg%. There was improvement in other parameters of lipid profiles namely HDL-C & LDL-C + VLDL-C and TAG.

Animals↗

PubMed2002

Pain measurement: a formidable task.

Pain is defined as unpleasant sensory and emotional experience, associated with actual or impending tissue damage. It consists of multi-dimentional phenomenon having sensory discriminative, cognitive-evaluative and effective motivational components. Though the technology has advanced, still it is very difficult to objectively assess all the attributes of pain, including alteration in cognitive behaviour. However, subjective methods like Visual Analog Scale rating (VAS) and preliminary objective methods like pain evoked responses, behaviral monitoring and event related evoked potentials for cognition are currently in vogue. It will take some more time and effort to evolve yet other newer and sophisticated techniques to measure all aspects of pain in human beings.

Animals↗

PubMed2002

Auditory evoked responses during different phases of menstrual cycle.

The electrophysiological correlates of changes in sensory function during menstrual cycle has already been studied and attributed to the hormonal influence. Effects of estrogen and progesterone on waves of auditory brainstem responses (ABR) have been reported and a hypothesis has been proposed that sex steroids have more influence on central auditory pathways. As mid-latency responses (MLRs) and slow vertex responses (SVRs) are better indicators of central auditory pathways, so MLRs and SVRs were also recorded besides ABRs in the present study. Waves of ABRs, MLRs & SVRs were recorded in 20 normal cycling females in 4 different phases of menstrual cycles from Cz-A1 and Cz-A2 position with alternating 90dB sound pressure click stimuli. Contralateral ear was masked with a white noise of -40 dBHL. With the same setting by changing the number of click stimuli, intervals of stimuli and filter bandpass the above 3 recordings were taken. The evoked responses in females having ovulatory cycles were compared within the four phases using ANOVA test. There is a trend of increase in peak latencies of ABR waves III and V and IPL I-V in estrogen-peak midcycle while decrease in latencies in progesterone-peak (interpeak latency) midluteal phase. Peak latencies of MLR waves No, Po, Na, Pa and Pb also show a same trend. SVR waves P2 and N2 are significantly delayed in mid-cycle (178.80 +/- 20.49, 276.65 +/- 18.32) while conduction is faster in midluteal phase (166.45 +/- 17.41, 261.95 +/- 21.07). Smallest latencies of all the waves are occurring during menstruation. These findings are suggesting that normal cyclical variations in the levels of estrogen and progesterone during menstrual cycle do affect the auditory pathways and effects are better seen on the central component.

Acoustic Stimulation↗

PubMed2001

Noise pollution: a study of noise levels in the operation theatres of a general hospital during various surgical procedures.

Noise, defined as any unwanted or undesirable sound, is a known environmental pollutant and health hazard. Sound levels during the entire surgical procedures were measured in the operation theatres (OTs) of a general hospital in Delhi, using a sound level meter, B & K 2209, on the dB(A) scale. The sound levels were found to be higher as compared to the recommended international standands. The noise was contributed mainly by doors, trolleys, equipment and alarms and the incessant conversation among the operation theatre (OT) staff. It is well documented that noise is stressful eliciting changes in the autonomic nervous system, impairing mental faculties and producing masking that could affect the staff and the conscious patient alike, leading to decreased work performance and increased anxiety respectively. Better acoustic designing and maintenance of equipment together with an increased awareness of the OT staff towards this vital factor of work environment may effectively reduce the noise pollution in OTs.

Humans↗

PubMed2001

Auditory evoked potential responses in menopausal women: a normative study.

Three types of auditory evoked potential responses i.e. auditory brainstem response (ABR), middle latency response (MLR) and slow vertex response (SVR) were studied in 22 post-menopausal Indian women to have a normative value for each response. Recordings were done on computerised evoked potential recorder using 10/20 system of electrode placement and standard click stimuli. The results were comparable with similar studies done in the western world indicating that there is no ethnic variation in evoked potential responses. The latencies of ABR waves showed an increase in menopausal females when compared with young adults indicating a delay in neural transmission which might be due to changed hormonal milieu of sex hormones after menopause. The normative values of MLR and SVR which represent the thalamo-cortical and cortical auditory projections are being reported in Indian menopausal women for the first time.

Aged↗

PubMed2001

Hypothalamo-pituitary-gonadal axis in control of female reproductive cycle.

Gonadotropin-releasing hormone (GnRH) secretion from the hypothalamus is pivotal to the regulation of reproductive physiology in vertebrates. The characteristic periodic secretion of gonadotropin releasing hormone (GnRH) from the medial basal hypothalamus (MBH), at the rate of one pulse an hour is essential for the maintenance of the menstrual cycle. These pulses are due to oscillations in the electrical activity of the GnRH pulse generator in the MBH. The GnRH pulse generator is under the influence of an assortment of interactions of multiple neural, hormonal and environmental inputs to the hypothalamus. Hence, a number of conditions such as stress, drug intake, exercise, sleep affect the activity of this pulse generator. Any deviation of normal frequency results in disruption of normal cycle. The cycle can become anovulatory in the hypothalamic lesions and can be restored by exogenous administration of pulsatile GnRH. Of late, studies have shown that pulse generator activity is also maintained by specific metabolic signals meant for energy homeostasis. Studies are in progress to work out cellular basis of GnRH pulse generator's rhythmic activation and role of Ca++ as second messenger for GnRH stimulated gonadotropin release. New concepts are emerging to find the existence of an FSH releasing factor, which independently regulates the activity of FSH.

Biogenic Monoamines↗

PubMed2000

Effect of glutamic acid and ketamine on morphine-induced analgesic response in rats.

Rats were treated with intraperitoneal injections of morphine (10 mg/kg) followed by glutamic acid (20 mg/kg.) and ketamine. (5 mg/kg). Pain thresholds were recorded as tail flick latencies for a period of 23 days and the mean area under curves calculated. Glutamic acid and ketamine, partially blocked the analgesic effects of morphine. Two types of effects were observed. In 4 animals, there was a partial blockade of the response, and in 2 animals there was a complete blockade followed by reversal in both the groups. It is suggested that two different mechanisms one excitatory and one inhibitory may be operating for the interaction of NMDA receptors with the opioid analgesic systems for modulating nociceptive responses.

Analgesics, Opioid↗

PubMed2000

Task related changes in ERP auditory vs visual tasks.

P3 component of event related potentials have been studied in relaxed state of mind. Changes in P3 latency and amplitude are expected if measured after a rigorous mental exercise. The event related potentials (ERP) were measured in 20 normal male subjects aged between 18 and 22 years. ERP was recorded twice in each subject before and after the administration of a mental task. The auditory mental task comprised of repeating in reverse order string of random digits read out to the subject at a uniform speed of 1 per second. The visual task comprised reading laterally inverted type written text. Each subject had to undergo 2 sessions in separate sittings. The latency and amplitude of P300 recorded before and after the task were compared statistically using Students' unpaired t-test. There was significant increase in P3 latency following both visual and auditory tasks (auditory task: before 330 +/- 24.43 msec and after 342.9 +/- 27.66 msec, similarly visual task: before 333.2 +/- 26.66 msec and after 345.65 +/- 26.56 msec). All other ERP waves latency and amplitude changes were insignificant.

Acoustic Stimulation↗

PubMed2000

Brainstem auditory evoked potential responses in iron-deficient anemic children.

Iron deficiency is a major health problem in developing countries manifesting not only as overt anemia but also involving the CNS resulting in cognitive and behavioral deficits. Iron is an important nutrient and essential element involved in myelin formation and neurotransmitter synthesis and thus contributes to normal neurological activity. Hypomyelination has been reported in iron deficient states with possible neural conduction defects. The brainstem auditory evoked potential response is used extensively to identify lesions associated with various demyelinating diseases and hence has been used in the present study to observe the effect of iron deficiency on sensory brain function. A trend of increased absolute and interpeak latencies and reduced amplitudes of the waves leading to a definite linear correlation between the severity of anemia and the degree of neurophysiological deficit suggests a subclinical involvement of the auditory pathway in the brainstem of iron deficient children.

Adolescent↗

PubMed2000

Task related changes in contingent negative variation (CNV) response of endogenous evoked potentials.

Contingent negative variation (CNV) is a slow negative cortical potential shift, which occurs during a warned foreperiod reaction time paradigm. Most studies of evoked potentials have concentrated on components occurring during the first 300 msec, although there are important and recordable aspects of signal processing occurring well beyond 300 msec e.g. late negative slow wave. CNV has proven sensitive to a number of psychological variables, none of which can yet be singled out as a definitive or exclusive correlate. Changes are expected if measured after a rigorous mental exercise. CNV was measured in 20 normal male subjects aged between 18 and 20 years. CNV was recorded twice in each subject before and after the administration of a mental task. The auditory mental task comprised repeating in reverse order string of random digits read out to the subject at a uniform speed of 1 per second. The visual mental task comprised reading laterally inverted type written text. Each subject had to undergo 2 sessions in separate sittings. The latency and amplitude of waves N1, P3, orientation (O), expectancy (E), CNV, reaction time (RT) were recorded. These values recorded before and after the task were compared statistically using student's unpaired t-test. The significant latencies recorded before and after the auditory task were, N1: 88.00 +/- 11.96 and 100.00 +/- 21.52 msec, P3: 289.00 +/- 54.85 and 299.00 +/- 52.91 msec, reaction time (RT): 102 +/- 17.05 msec and 123 +/- 17.5 msec, and in case of visual task, N1: 88 +/- 13.16 msec and 99.00 +/- 16.51 msec, reaction time (RT): 107 +/- 11.74 msec and 127 +/- 13.42 msec respectively. All other CNV wave latencies and amplitude changes were insignificant. Hence task effects sensory perception as reflected by increased latency of the long latency response N1 and the cortical integrative processes resulting in increased reaction time.

Adolescent↗

PubMed2000

Event related evoked potential responses in epileptic patients.

The effect of epilepsy on cognitive functions has been investigated in this study. The P300 auditory event related potentials (AERP), Wechsler Adult Performance Intelligence Scale (WAPIS--Indian Adaptation) & Digit Span Test (DST) have been used to assess the cognitive status. Twenty primary generalised epilepsy patients and 20 normal controls were subjected to WAPIS & DST testing and their AERP recorded. On comparative statistical analysis, epileptic subjects were found to have significantly higher N2 & P300 latencies and lower P300 amplitude, WAPIS-IQ scores & DST scores. These findings suggest that there is a general decline of cognitive functions in epileptics especially the memory, attention, concentration and speed of mental processing and as also corroborated by P300 and that P300 can be used as an additional sensitive parameter to assess the cognitive status.

Adolescent↗

PubMed1999

Involving students in question writing: a unique feedback with fringe benefits.

A contest on question writing was organized during the undergraduate medical physiology teaching program. Students were asked to write and submit multiple-choice questions of the assertion-reasoning type (type E) in physiology. The winners were decided after the questions submitted were graded on a six-point scale (0-5) that considered both thematic novelty and construct correctness. Of the 100 students in the class, 37 participated in the contest, and a total of 912 questions was received. The contest encouraged the students to go through their subjects critically. The questions provided the instructor with insight into the learning habits and misconceptions of the students and provided the grist for animated discussions in tutorial classes. Although several types of errors were deciphered in these questions, with suitable modifications the questions helped the faculty build up a sizable question bank.

Education, Medical↗

PubMed1999

Brainstem auditory evoked potentials among rubber factory workers.

The study was conducted on 27 rubber factory workers for the functional assessment of brainstem auditory pathway. Neurobehavioural questionnaire was administered to the workers and the personal sampler was used to evaluate the respirable particulate load inhaled per day of each worker along with qualitative analysis for PAH compounds. Evoked potential recording was carried out for brainstem auditory responses. Chest X-rays of workers exhibited varied abnormal features. Multiple regression analysis of data showed definite prolongation of latencies with increasing concentration of respirable particulate load though it was not statistically significant. Comparison with normative data indicated prolongation of latencies of rubber factory workers.

Adult↗