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Biomedical subjects

S P Kumar

Publications and source records attributed to S P Kumar.

At least 19 recordsLinked to original sources
PubMed2003

The Babinski sign--a critical review.

In 1896, Josph Babinski, a French neurologist, first described the best known neurologic eponym--"the Babinski sign". This sign is characterised by dorsiflexion of the big toe, by recruitment of the extensor hallucis longus muscle, on stimulating the sole of the foot. He himself emphasised from the outset the intimate relationship between this sign and the shortening movement in other leg muscles, which forms the flexion synergy of the lower limb. The Babinski sign is not a new reflex, rather it is released as a result of breakdown of the harmonious integration of the flexion and extension component of the normal defence reflex mechanism, due to pyramidal tract dysfunction. A pathological Babinski sign should be clearly distinguished from upgoing toes that may not always be a part of the flexion synergy. This article reviews the Babinski sign in detail, focusing on the historical perspectives, role of pyramidal tract dysfunction, art of elicitation and interpretation. The significance of assessing this phenomenon in the entire leg and the clinical clues that will help to dispel the myths regarding the Babinski sign has been emphasized.

Eponyms↗
PubMed2001

Free radical scavenging active components from Cedrus deodara.

An activity-directed fractionation and purification process was used to identify the antioxidant components of Cedrus deodara. Dried heartwood powder of C. deodara was first defatted with petroleum ether and then extracted with chloroform. The chloroform extract showed strong antioxidant activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical. This fraction was then subjected to separation and purification using silica gel column chromatography. Three compounds with potent antioxidant activity were isolated in significant yields and identified by spectroscopic methods ((1)H NMR, (13)C NMR, IR, and MS). They were identified as (-)-matairesinol, (-)-nortrachelogenin, and a dibenzylbutyrolactollignan (4,4',9-trihydroxy-3,3'-dimethoxy-9,9'-epoxylignan). This is the first report of the occurrence of these compounds in C. deodara.

Antioxidants↗
PubMed2000

The Babinski sign--a reappraisal.

In 1896, Joseph Babinski, a French neurologist, first described the best known neurologic eponym 'the Babinski sign'. This sign is characterised by dorsiflexion of the big toe and recruitment of the extensor hallucis longus muscle, on stimulating the sole of the foot. He has emphasised from the outset, the intimate relationship between this sign and the shortening movement in other leg muscles, which form the flexion synergy of the lower limb. The Babinski sign is not a new reflex, rather it is released as a result of breakdown of the harmonious integration of the flexion and extension components of the normal defence reflex mechanism, due to pyramidal tract dysfunction. A pathological Babinski sign should be clearly distinguished from upgoing toes that may not always be a part of the flexion synergy. This article reviews the Babinski sign in detail, focusing on the historical perspectives, role of pyramidal tract dysfunction and art of elicitation and interpretation. The significance of assessing this phenomenon in the entire leg, and the clinical clues that will help to dispel the myths regarding the Babinski sign, have been emphasised.

Humans↗
PubMed1999

Profile of antiepileptic pharmacotherapy in a tertiary referral center in South India: a pharmacoepidemiologic and pharmacoeconomic study.

PURPOSE: To study the current pharmacotherapy practices of epilepsy and its economics in a developing country by correlating the epidemiology and economics of antiepileptic drug (AED) treatment in general epilepsy care and comprehensive epilepsy care. METHODS: We compared the AED-use profiles, efficacy, and tolerability at entry and at last follow-up for 972 patients seen at a comprehensive epilepsy care program in South India from 1993 to 1995. The relative cost was expressed as the average percentage of the per capita gross national product (GNP/capita) each individual spent for AED treatment. RESULTS: At entry, 562 (57.8%) subjects were receiving polytherapy; at last follow-up, 743 (76.4%) patients were receiving monotherapy, an increase of 34.3% in the use of monotherapy. One or more adverse drug reactions were reported by 28.6% of patients at entry and by 19.8% at last follow-up. The proportion of patients who were seizure free increased from 29.0 to 44.8%. Carbamazepine (CBZ) was the most frequently used AED, followed by diphenylhydantoin (DPH), valproate (VPA), and phenobarbitone (PB). The relative cost (% GNP/capita) for standard AEDs were as follows: PB, 4.4%; DPH, 7.1%; CBZ, 16.8%; and VPA, 29.5%. The average annual cost of AED treatment per patient in U.S. dollars was $64.32 at entry and $47.73 at last follow-up. Reduction in polytherapy resulted in the net annual saving of $16,128 ($16.59 per patient, or 5.4% GNP/capita). CONCLUSIONS: The more frequent use of relatively expensive drugs like CBZ and VPA and the use of polytherapy-still quite prevalent in developing countries-has escalated the cost of AED therapy. Although in recent years AEDs have become more available in developing regions, primary and secondary care physicians have not been adequately educated about the current trends in the pharmacotherapy of epilepsy.

Adolescent↗
PubMed1998

"Changing trends (clinico-biochemical) in gall-bladder stone disease"--an observation.

Present study has been undertaken to know the causative factors responsible for change in trend of gall-stone disease from middle aged, fertile, fat females to young asthenic females in twenties. Our findings reveal high incidence of gall stone formation in non-obese young females. Average fat consumption in non-obese patients was less (17%) than that of obese (26%). However, use of oral contraceptives was high in non-obese females and maximum users were in young age group while in obese in middle age group. Bilirubin content in gall bladder stones of non-obese was significantly more than that of obese (p < 0.01) whereas cholesterol content in gall bladder stones of obese was significantly high when compared to non-obese subjects. Analysis of bile showed significant increase in bilirubin and calcium level of non-obese when compared to control and obese subjects whereas phosphorus levels were significantly decreased in the bile of non obese subjects. These findings suggest that in non-obese females less intake of fat, early use of oral contraceptives, higher contents of bilirubin and calcium and low content of phosphorus in bile may be responsible for gall stone formation.

Adult↗
PubMed1996

The sheep as an animal model for heart valve research.

The first test used to assess new heart valve prostheses and devices is to implant them in a medium-sized animal. This is a costly piece of research and it is important to select the most appropriate animal. The authors feel that the sheep is an appropriate animal model for heart valve research and describe their experience in this area. It is hoped that the detailed description provided will be useful to any other group contemplating similar studies.

Animals↗
PubMed1996

Critical role of the sinuses of Valsalva in the durability of valved conduits.

BACKGROUND AND AIMS OF THE STUDY: Most work in search of an ideal extracardiac valved conduit has assumed that the type of tissue used for construction is the determining factor for its behavior and durability. The excellent results of our study with a valved conduit incorporating sinuses of Valsalva and made of autologous pericardium showed that the design plays a crucial role in addition to the type of material. MATERIALS AND METHODS: We report the experimental results of three different pericardial sinus bearing valved conduits made of 0.5% glutaraldehyde treated autologous pericardium (Group 1), dye mediated photooxidized bovine pericardium (Group 2), and glutaraldehyde treated bovine pericardium (Group 3) implanted in the right ventricular outflow tract of sheep. Groups 1, 2 and 3 had 11, 11 and four animals available for assessment out of 12, 18 and six implantations respectively. The valved conduits were explanted at varying intervals between one and 11 months. The conduit function was assessed with hemodynamic, echocardiographic and Doppler studies both at the time of implantation and sacrifice. The explanted conduit was studied macroscopically and subjected to histopathologic examination. RESULTS: The hemodynamic and echocardiographic studies at implantation showed very satisfactory results in all three groups. At the time of sacrifice, Group 1 showed consistently good results. In a significant number of animals in Groups 2 and 3, one, two or even three cusps had become adherent to the conduit wall, resulting in severe regurgitation. The sinuses were well preserved in Group 1, while they were less prominent in Group 2 and least in Group 3. Histopathologically, the three groups basically showed the same feature, a process of fibrocellular proliferation resulting in thickening. In this study the adhesion of the cusps to the sinus wall was related to the degree of prominence of the sinuses of Valsalva, which in turn depended on the ability to shape the pericardium at the time of construction of the valved conduit. CONCLUSIONS: This study stresses the importance of the sinuses in the behavior of the semilunar valve leaflets.

Animals↗
PubMed1995

Comparison of fresh and glutaraldehyde-treated autologous stented pericardium as pulmonary valve replacement.

The use of fresh autologous pericardium in valve surgery has shown poor results in the past mainly due to thickening and retraction. Recently, it has been suggested that a short treatment with glutaraldehyde might radically change its behavior. In an attempt to determine whether this disparity in results is due to the glutaraldehyde treatment or to a better present-day surgical technique, fresh and glutaraldehyde-treated autologous pericardium was mounted in a frame and implanted in the pulmonary position of adult sheep. Six survivors obtained in each group were sacrificed between 2 and 8 months in the "fresh" group and between 2 and 6 months in the "glutaraldehyde-treated" group. Macroscopically, the fresh pericardium became thickened and retracted in all specimens, eventually resulting in severe regurgitation, while the glutaraldehyde-treated, although slightly thickened, retained its pliability without significant retraction. Microscopically, viability of the central core of the collagen was more often preserved in the fresh pericardium. Endothelialization was irregular. In conclusion, short glutaraldehyde treatment seems to improve the results of autologous pericardium mounted on a valve stent. Its effect on calcification remains to be ascertained.

Animals↗
PubMed1995

In situ mitral valve stabilization with glutaraldehyde.

Mitral valve repair in the young rheumatic patient carries a high reoperation rate due to progression of the disease. In an attempt to halt or at least slow down this process, the possibility of fixing in situ the valve tissues with glutaraldehyde was explored. Six weanling sheep underwent tanning of their anterior mitral leaflet for two minutes with 0.5% buffered glutaraldehyde. The non-treated posterior mitral leaflet served as control. The animals were sacrificed at varying intervals between 2.5 and 6 months. At sacrifice, Doppler echocardiography and hemodynamic studies were done. The leaflets were subjected to histopathologic examination and calcium and glutaraldehyde contents were estimated. Glutaraldehyde treatment of the anterior leaflet caused thickening of the cusp and chordae associated with partial devitalization of its core tissue, partial loss of endothelium and intense fibrocellular reaction with abundant elastic fibers without altering its functional integrity. It did not induce calcification. There were no detectable levels of glutaraldehyde at explantation. The posterior mitral leaflets were normal. Although the absence of calcification and partial viability of the tissue are encouraging, it does not necessarily follow that this treatment would arrest progression of the underlying disease. This process may have clinical application in the future, but it is not yet recommended.

Animals↗
PubMed1994

Functional analysis of spontaneous movements in preterm infants.

Spontaneous movements of premature infants between 25 and 34 weeks conceptional age were observed for 1 hr on two or three occasions. Subjects had low-risk prognoses and were clinically stable at the time of testing. Behavioral acts were scored using a 0/1 time sampling technique in 60 continuous, 1-min time blocks. Temporal associations between individual movements were found using chi-square analyses. Some associated behaviors contained combinations consistent with neonatal action patterns, for example, single and bilateral leg kicking, head turning, and mouthing. Features of state organization were also evident in that general motor activity (GM), which has been used as a marker of active sleep (AS) in neonates, was found to cluster temporally with startle, facial, and head movements but not eye movements. Behavioral quiescence (> or = 5 s) was dissociated from AS-related behaviors (GM, facial, head, and eye movements). Combinations of state-segregated behaviors were more likely to exhibit co-occurrence within 1-min intervals in infants 30 weeks conceptional age and older.

Arousal↗
PubMed1994

Neonatal cushingoid syndrome resulting from serial courses of antenatal betamethasone.

BACKGROUND: Antenatal steroid therapy has been shown to induce accelerated pulmonary maturation in preterm fetuses when delivery is imminent. Although this form of therapy has been used for 20 years, few studies or case reports have discussed the indications for or complications of retreatment, especially when more than two courses of steroids have already been given. We report a case of neonatal cushingoid syndrome with hypothalamic-pituitary-adrenal axis suppression following maternal treatment with seven courses of betamethasone. CASE: A 31-year-old white woman, gravida 3, para 1, spontaneous abortion 1, presented with a single intrauterine pregnancy at 24 weeks' gestation, a bulging amniotic sac, and repeated cerclage failure. Antenatal betamethasone therapy was begun at 12.5 mg intramuscularly every 12 hours for two doses. Because of cervical dilatation, bulging membranes, and intermittent contractions, the expectation of imminent premature delivery did not diminish over the next 42 days. As the effect of antenatal steroids wanes after 7 days, a course of therapy was administered each week for as long as the threat of preterm delivery remained. Seven courses of betamethasone were given before delivery at 34.5 weeks post-conception age. The 2625-g male neonate appeared cushingoid on physical examination, with basal serum cortisol levels less than 3.3 micrograms/dL. CONCLUSION: Physical findings of the neonate and laboratory investigation of both infant and mother suggested combined hypothalamic-pituitary-adrenal axis suppression. The cushingoid features of the infant demonstrate an undesired and previously unreported complication of an effective antenatal therapy. The unusual variant in this case was that the initial indication for steroid therapy (risk of premature delivery) persisted for 8 weeks after the first dose of betamethasone. It remains unknown how many weekly antenatal steroid courses can be administered before marked fetal adrenal suppression becomes evident. Risk-benefit ratios should be carefully considered before each retreatment.

Adult↗
PubMed1993

Effects of caloric restriction and dietary fat on epithelial cell proliferation in rat colon.

Epidemiological studies indicate that caloric intake and dietary fat content influence colonic carcinogenesis. In rodents, caloric restriction reduces, and some fats increase, carcinogen-induced colon cancer incidence. The present study was designed to investigate the effects of caloric restriction on colonic cell proliferation (CCP) in carcinogen-treated or control rats fed low- or high-fat diets. F344 rats were treated with azoxymethane (15 mg/kg x2) and then fed an isocaloric AIN 76A diet containing either 5 or 23% corn oil, ad libitum or calorie-restricted to 70 or 80% of the kilocalories consumed by ad libitum rats. Biopsies of the distal colon were taken at 10 and 20 weeks, and rats were sacrificed at 21 or 34 weeks on the experimental diets. Distal CCP was determined by microautoradiography after [3H]thymidine labeling in vitro or presacrifice administration in vivo. The labeling index and number of labeled cells per crypt column were significantly reduced by caloric restriction at all time points (10, 20, 21, 34 weeks). Caloric restriction reduced CCP in high fat- and low fat-fed rats and in azoxymethane-treated and control rats. High fat resulted in decreased CCP in the distal colon compared to low fat at 34 weeks but not earlier. The findings indicate that: (a) caloric restriction is effective in favorably modulating CCP, an intermediate biomarker of colon cancer risk; (b) a high fat ad libitum diet, which increased tumor yield, does not increase distal colon proliferation; (c) dietary fat intake alters proliferation in a manner differing from that induced by changing dietary caloric intake.

Animals↗
PubMed1993

Spontaneous motility in premature infants: features of behavioral activity and rhythmic organization.

The spontaneous motor activity of clinically stable premature infants, 26-36 weeks gestational age, was investigated. Movements were recorded using a pressure-sensitive transducer positioned below the infant's head and torso. Behavior samples were digitized every 0.5 s during 2 and 3-hr continuous recording sessions. Time-series analyses revealed prominent motility cycles of circa 80 min and circa 30 min. These results are consistent with periodicities in motility and REM activation observed in full-term neonates. The longer rhythms of 70-100 min of motility found in this study establish that these periods are present at this stage of development independent of maternal zeitgebers. Developmental changes in motility rhythms and movement burst durations were also observed. Bout durations became somewhat longer in older (> 30 weeks) infants, but the relative time devoted to movement per session was comparable in older and younger (< or = 30 weeks) infants.

Age Factors↗