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Biomedical subjects

P Kumar

Publications and source records attributed to P Kumar.

At least 595 records · Page 33Linked to original sources
PubMed1989

The effect of some of the polyphenolic compounds on sperm motility in vitro: a structure-activity relationship.

Many of the common polyphenolic compounds which are naturally present in abundance in plant extracts, exercise inhibitory effects on mammalian sperm motility in vitro, which could be the cause of the antifertility effects of the crude plant extracts. The action of these polyphenolic compounds seems to be structure-dependent. Their activity was found to be dependent on the positions of hydroxyl groups and modulated by the positions of methyl groups on the benzene ring. Carbon-carbon double bond on the side chain of cinnamic acid series compounds was essential for their activity. One of the plausible actions of polyphenols on spermatozoa seems to be the augmentation of the generation of superoxide radicals by them, which might be involved in the inhibition of their motility in vitro.

Animals↗
PubMed1989

Sulphuric acid burns: report of a mass domestic accident.

An unusual domestic accident involving concentrated sulphuric acid and affecting seven children ranging between 3 and 7 years is reported. Three had major burns with one having a 60 per cent mostly full skin thickness burn. This last patient is reported in detail and problems of sulphuric acid burns and their management are discussed.

Accidents, Home↗
PubMed1989

The effect of chronic hypoxia upon the development of respiratory chemoreflexes in the newborn kitten.

1. We have studied the reflex respiratory responses to two-breath alternations of fractional inspired oxygen (FI,O2) in normoxic (reared in room air) and chronically hypoxic kittens (born into and reared in an FI,O2 of 0.13-0.15) on post-natal days 1, 2-3, 4-8 and 9-14. 2. Respiration was measured non-invasively in the unanaesthetized kittens. Test runs (with alternations of FI,O2 between 0.21 and 0.14) and control runs (with an FI,O2 of 0.21) were carried out during quiet sleep. 3. The degree of alternation in tidal volume, inspiratory time, expiratory time, frequency, drive, timing and instantaneous ventilation components of the respiratory response was compared during control and test runs. 4. There was little response to control runs in either group at any post-natal age. 5. In normoxic kittens we found no significant reflex response in any respiratory variable to test runs before day 4. However significant alternation was found in expiratory time, frequency and ventilation at days 4-8 and in tidal volume at days 9-14. 6. In chronically hypoxic kittens there were no significant differences between control and test runs at any of the ages studied. 7. In the normoxic group increases in the response with post-natal age probably reflect post-natal increases in the sensitivity of the peripheral chemoreceptors. The lack of development in the chronically hypoxic group may indicate abnormal function or delayed maturation of the peripheral chemoreceptor sensitivity to hypoxia. 8. The results suggest that the method can be used to detect developmental and pathological changes in the arterial chemoreflex.

Animals↗
PubMed1989

Non-specific cardiovascular depressant effect of methyl isocyanate (MIC) in rats.

Methyl isocyanate (MIC) either inhaled (5, 10 mg/lit) or administered by intravenous (5, 10, 28 mg/kg) or subcutaneous (1300, 1500 mg/kg) routes produced a dose dependent fall in blood pressure (BP) and heart rate (HR) in anaesthetised rats. Higher doses (10 mg/lit inhalation, 10 & 28 mg/kg i.v., 1500 mg/kg s.c.) increased the lung body weight index (LBI) and tracheobronchial resistance (TBR) concomitant with gross pulmonary damage and edema. However, lower doses (5 mg/lit inhalation, 5 mg/kg i.v., 1300 mg/kg s.c.) produced the cardiovascular depressant effect without affecting LBI, lung morphology and TBR. The effects of MIC on BP, HR and TBR were not counteracted by muscarinic, histaminic and 5-HT receptor blockers and by vagotomy. Studies with hydrolysis products of MIC showed that relatively large doses of methylamine (MA) and dimethylurea (DMU) (i.v.) produced cardiovascular depressant effects, without affecting the LBI & TBR. The results indicate that the cardiovascular depressant effect of MIC may not be entirely a sequel to its effect on respiratory organs, release of vasoactive substances or its hydrolysis products. A non-specific cardiovascular depressant effect of MIC is suggested.

Airway Resistance↗
PubMed1989

Long latency cutaneous reflex effect on H-reflex recovery in hemiplegics and paraplegics: a longitudinal study for the assessment of motor function.

H-reflex recovery by twin pulses was recorded serially in 10 paraplegics for 5 months and in 23 hemiplegics for 2 months after the lesion. Fifty-one normal subjects acted as controls. The effect of cutaneous tactile stimulation was also studied simultaneously by applying electrical stimuli synchronized with twin pulses to the skin over the lateral border of small toe. In paraplegics, the H-reflex recovery curves recorded serially showed a highly depressed pattern during the first two weeks, an almost normal pattern during the second and third months and a significantly elevated pattern during the fourth and fifth months. Whereas cutaneous stimulation in control subjects produced a highly significant late inhibition of H-reflex recovery between 600 ms and 600 ms, in paraplegics it failed to produce any significant effect, except in two, who besides having a normal H-reflex recovery curve even during the first week, showed a substantial amount of cutaneous inhibition of H-reflex recovery, 4 months after the lesion. A highly depressed pattern of H-reflex recovery was observed on the affected side of the majority of hemiplegics during the first week after the lesion, many of them showing similar pattern on the "unaffected side" also. The serial study showed very good improvement in all hemiplegics both in terms of H-reflex recovery pattern and the amount of cutaneous inhibition. The observations in present study suggest preservation and/or restoration of supraspinal influences in many hemiplegics and in at least two paraplegics. The study also shows that a serial recording of H-reflex recovery curve and the amount of cutaneous reflex effect on it, is a very sensitive method of assessing the supraspinal influences on the spinal motoneurones and so can be of immense help in the diagnosis and prognosis in hemiplegics and paraplegics.

Female↗
PubMed1989

Re-setting of the hypoxic sensitivity of aortic chemoreceptors in the new-born lamb.

We tested to see whether the steady-state hypoxic sensitivity of aortic chemoreceptors was re-set during the first 2-3 weeks of post-natal life. Aortic chemo-receptor activity was recorded from the distal end of the cut aortic branch of the cervical vagus in pentobarbitone - anesthetized, new-born lambs. Two groups were studied, the first aged 1-4 days and the second aged 10-19 days. Chemoreceptor discharge increased as hyperbolic function with increasing isocapnic hypoxia in both groups and we quantified the position and the shape of this response curve. It was shifted to the right significantly in the older group of lambs, the mean vertical asymtote increasing from 10.00 to 27.95 torr PO2. No significant difference was found in the horizontal asymotote or in the 'shaping term' between the two groups. The greatest differences between the stimulus-response curves of the two groups of animals with respect to the mean level of discharge and the slope of the curve occurred when PaO2 was below ca. 50 torr. The aortic chemoreceptors of older lambs were unable to maintain a sustained discharge at arterial PO2 values below ca. 30 torr. In contrast, in the younger group PO2 often had to be reduced below this level before discharge increased significantly. We conclude that, like the carotid chemoreceptors, aortic chemoreceptor sensitivity is re-set over the first few weeks of life. The re-setting may contribute to the increase in the ventilatory response to hypoxia which occurs over this period.

Action Potentials↗
PubMed1989

Autonomic function tests in cases of chronic severe anaemia.

Autonomic functions were studied in 30 adult cases of chronic severe anaemia (CSA) and equal number of age and sex matched healthy controls. Blood pressure and heart rate responses to standing, to respiration (expiratory-inspiratory ratio), to Valsalva manoeuvre (Valsalva ratio) and to hand immersion in ice cold water and given 1.8 mg of atropine intravenously were studied. Patients with CSA had significantly high basal pulse rate and low blood pressure as compared to control subjects (p less than 0.001). The expiratory inspiratory ratio was abnormal in 30% of the cases of CSA (p greater than 0.10) valsalva ratio was abnormal in 50% of cases (p less than 0.01) and postural tachycardia was observed in 60% of cases (p less than 0.001). Normal response to hand immersion in ice cold water was observed in 56.6% of cases (p less than 0.001). Atropine resulted in tachycardia in 73.4% of cases of CSA as compared to 86.7% of controls (p less than 0.10). All the cases of CSA showed one or more abnormal response and in 16.6% of cases all responses were abnormal.

Adult↗
PubMed1989

Neurological application of botulinum toxin.

Botulinum toxin, a potent biological toxin with paralytic properties, has found use as a therapeutic agent in various diseases. The authors review the toxin's therapeutic value in three neurological diseases.

Blepharospasm↗
PubMed1989

Post sclerotherapy esophageal ulcers: a prospective analysis of their behaviour.

The reported incidence of post sclerotherapy esophageal ulcers has shown marked variation, possibly due to lack of uniform criteria for their diagnosis. Using fixed criteria (size greater than or equal to 5 mm, duration greater than or equal to 2 weeks), we prospectively studied 82 patients with portal hypertension, who underwent four or more sessions of endoscopic sclerotherapy (EST), for the occurrence and behaviour of these ulcers. Post sclerotherapy ulcers occurred after 43 (9.2%) of 465 EST sessions in 30 (36.6%) of 82 patients. Ulcers were significantly associated with two complications: rebleed during the course of sclerotherapy (33% of ulcers bled compared to 3% from variceal rupture; p less than 0.001) and esophageal stricture formation (66.7% of strictures occurred in patients who had ulcers; p less than 0.05). Ulcers occurred more frequently in patients with poor liver function (61.5% in Child's C grade compared with 31.9% in Child's A or B grades; p less than 0.05) and after injection into larger varices (83.7% in varices grades 3 and 4, 16.3% in lower grades; p less than 0.005). Severe persistent chest pain (p less than 0.001) and pyrexia (p less than 0.01) after sclerotherapy were clinical pointers of ulcerogenesis.

Adult↗
PubMed1988

Rationalisation of regimens of treatment of kala-azar with sodium stibogluconate in India: a randomised study.

The efficacy and safety of six regimens of treatment for kala-azar (visceral leishmaniasis) with sodium stibogluconate were evaluated in a prospective randomised study to ascertain the optimal treatment for Indian patients. Altogether 371 patients with kala-azar were randomised to receive sodium stibogluconate intramuscularly at a dose of 10 mg/kg body weight/day for 20 or 40 days (groups A and A1, respectively), 15 mg/kg body weight/day for 20 or 40 days (groups B and B1, respectively), or 20 mg/kg body weight/day for 20 or 40 days (groups C and C1, respectively). Patients were examined blind before and at the end of treatment and every month for six months. The number of patients who were apparently cured--that is, those whose temperature had returned to normal at the end of their regimen of treatment--was 45 (78%) in group A, 53 (87%) in group A1, 50 (81%) in group B, 60 (95%) in group B1, 58 (92%) in group C, and 62 (97%) in group C1. At six months 62 patients (97%) in group C1, 51 (81%) in group C, 54 (86%) in group B1, 42 (68%) in group B, 45 (74%) in group A1, and 33 (57%) in group A had not relapsed and were cured as confirmed by a bone marrow aspirate free of parasites. The differences between groups C1 and C, B1 and B, and A1 and A were significant. Logistic regression of the proportion cured with the dose and length of treatment showed that both factors were significant in improving the rate of cure; the highest dose for the longer time (group C1) had the best rate of cure. One patient in group C1, 12 in group C, nine in group B1, 18 in group B, 15 in group A1, and 23 in group A were cured with extended courses of 20 mg sodium stibogluconate. One patient in each of groups C1, B, A1, and A became unresponsive to antimony and were cured with pentamidine. One patient in each of groups C1, B, and A became unresponsive to both antimony and pentamidine. The patients tolerated the longer duration of treatment safely, and side effects were minor. Sodium stibogluconate should be given intramuscularly in the dosage of 20 mg/kg for at least 40 days, when patients should be assessed for further treatment if necessary. Such a regimen should achieve the highest rate of cure with low toxicity and low rates of relapse and unresponsiveness.

Antimony Sodium Gluconate↗
PubMed1988

Tamm-Horsfall protein is a marker of renal and extra-renal rhabdoid tumours.

A monoclonal antibody (MAb) to Tamm-Horsfall protein (THP) was used to stain 6 renal rhabdoid tumours (RRT) and 2 primary extra-renal rhabdoid tumours (E-RRT). One of the E-RRT was a tumour from the posterior fossa of a 3-year-old child and the other was a lump from the right side of the neck in an 18-month-old girl. Five of 6 RRT and both cases of E-RRT were positive for THP. Both cases of E-RRT also reacted with vimentin and cytokeratin MAbs. On electron microscopy, cells from both E-RRT were seen to contain concentric whorls of intermediate filaments characteristic of rhabdoid tumours. Viable tissues from one RRT and one E-RRT (the posterior fossa tumour) were available for tissue culture. Ninety-five percent of the cells growing out of both tumours were polygonal and approximately 5% of these cells were THP-positive.

Biomarkers, Tumor↗
PubMed1988

Benign disease of the common bile duct.

The incidence of common bile duct (CBD) pathology in a group of patients with benign biliary disease (n = 505) was found to be 23.2 per cent. The spectrum included 111 patients (90.2 per cent) with CBD stones, 37 of whom (33.3 per cent) had no symptoms or findings pre-operatively indicating CBD involvement. Five patients had papillary stenosis, three had postoperative CBD strictures, one had a choledochal cyst and one had an external biliary fistula. Of the 100 CBDs measuring more than 10 mm in diameter, 90 harboured calculi. In the remaining 23 CBDs measuring less than 10 mm, calculi were present in 21. The presence of CBD calculi was demonstrated by intra-operative cholangiography in 49 patients. In the remaining patients (n = 74), the diagnosis of CBD pathology was made either by percutaneous transhepatic cholangiography, endoscopic retrograde cholangio-pancreatography, T-tube cholangiography or peroperative palpation. The surgical procedures performed included choledochotomy and T-tube drainage (n = 74), transduodenal sphincteroplasty (n = 27) and choledochoduodenostomy (n = 18). The overall mortality and morbidity of CBD exploration was 3.3 per cent and 24.4 per cent respectively, which was significantly greater than that for cholecystectomy alone (0.3 per cent and 8.6 per cent respectively). Transduodenal sphincteroplasty carried a much higher mortality (11 per cent) and morbidity (52 per cent) when compared with other procedures.

Cholangiography↗
PubMed1988

Behavioral studies in petrol pump workers.

Behavioral studies were conducted on 90 petrol pump workers to study the effect of petrol on the central and peripheral nervous systems. Sixty-four control subjects of similar age and socio-economic status were also taken for purposes of comparison. Maudsley Personality Inventory (MPI), Benton Visual Retention Test, Digit Span Test, Progressive Matrices, Digit Symbol Test and Mirror Drawing Test were used for behavioral studies. Immediate and delayed memory were found to be significantly affected in exposed workers. Intellectual capacity and psychomotor ability were also significantly affected (P less than 0.01). Psychomotor ability and visuomotor learning ability were more affected (P less than 0.05) among the exposed subjects than among the controls. However, stability and extroversion-introversion ability remained unaffected.

Humans↗