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Biomedical subjects

S B Lall

Publications and source records attributed to S B Lall.

At least 37 records · Page 2Linked to original sources
PubMed1991

Peripheral and renal vein renin activity in patients with renovascular hypertension due to nonspecific aortoarteritis.

The diagnostic utility of peripheral and renal vein renin estimations in relation to angiographic findings was evaluated in 13 patients with renovascular hypertension and non-specific aortoarteritis (NSAA, Gr I), in comparison with 10 patients with renal artery stenosis due to other causes (Gr II). Plasma renin activity (PRA) was measured by radioimmunoassay. Blood samples were collected after angiography from the femoral vein and renal vein on the affected side followed by sampling from the less affected or unaffected side. Renal vein renin ratio (RVRR) was calculated from renal vein renin values. The effect of captopril (25 mg oral) on blood pressure, PRA, and RVRR was examined in 8 patients from each group. Normotensive volunteers (8) with moderately low salt intake were also included in the study for comparison of twenty-four-hour urinary sodium output, peripheral PRA, and response to captopril. The mean peripheral PRA was high in both groups as compared with normotensive controls; however, the values were lower in patients with NSAA. The rise in PRA in response to captopril was insignificant in Gr I (p greater than 0.05) and RVRR greater than 1.5 was observed in 5 of 13 patients in contrast to 9 of 10 in Gr II (p less than 0.05). A paradoxical ratio, ie, (high renal vein renin levels on the less stenotic side) was noticed in 3 patients of Gr I, whereas none of the patients of GR II showed such a ratio. An improvement in RVRR after captopril was observed in 50% of patients of Gr I as compared with a marked response in all patients of Gr II.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Physical and behavioral development in rats after late prenatal exposure to diazepam.

The effect of late prenatal exposure to diazepam (DZP) on physical and behavioral development of rat pups was investigated. Prenatal exposure to DZP (20 mg/kg, sc, in last week of pregnancy) did not alter litter size and no gross malformations were noted at birth. Body weight at birth and subsequent weight gain was significantly less in these animals. The development of reflexes and neuromuscular maturation was normal. Open field locomotor activity and rearing scores were significantly decreased. Test of social play in juvenile rats revealed normal pattern of sexual dimorphism with increased masculinized behavior. Acquisition and retention of passive avoidance task was not affected by DZP exposure, however, retention of brightness discrimination task was significantly decreased. The hypnotic effect of a challenge dose of DZP and convulsive effect of pentylene tetrazole remained unaltered. Open field activity test in adult animals revealed increased ambulation. Probe dose of amphetamine in these animals caused paradoxical decrease in activity. It is concluded that exposure to high dose of DZP during late prenatal period may not manifest in physical or neuromuscular impairment during early development period, except for weight loss, however, it may have long term effects on behavior becoming manifest in adolescence and at maturity.

Amphetamine↗
PubMed1990

Increased brainstem angiotensin-I levels in chronic 2 KIC hypertensive rats.

A study was undertaken on the role of brainstem renin-angiotensin system in maintenance of hypertension in chronic renovascular hypertensive rats. Hypertension was induced by unilateral renal artery clamping, while the contralateral kidney was left intact (2 KIC). Blood pressure (BP), plasma renin activity (PRA) and brainstem angiotensin (ang-I) levels were measured after 24 days, in hypertensive and sham-operated animals. In separate subgroups of these animals, the effect of intracerebroventricular administration of captopril on the parameters listed was studied. The results showed high ang-I levels in 2 KIC rats as compared to controls (P less than 0.05). Captopril administration (500 micrograms/50 microliters icv) caused a fall in BP and increase in brainstem ang-I levels (P less than 0.01). In control animals, however, captopril produced a rise in BP without any significant change in brainstem ang-I levels. Peripheral plasma renin activity was normal, despite significant sodium retention in 2 KIC rats. The results are suggestive of activation of brainstem renin-angiotensin system (RAS) in chronic 2 KIC hypertension.

Angiotensin I↗
PubMed1987

Comparison of histoenzymological alterations in the contralateral ovary of nulliparous and parous females of the bat Taphozous melanopogon melanopogon Temmnick (Microchiroptera, Mammalia) displaying absolute dextral dominance of the genital tract.

Taphozous melanopogon melanopogon is a unique emballonurid microchiropteran which exhibits a 100% dextral dominance of the female genital tract. Folliculogenesis occurs in the contralateral ovaries, but it is only in the right ovary that a single Graafian follicle attains maturity and ovulates. The product of fertilization is implanted in the dextral uterine cornu. Seven types of follicles were identified in the right ovary, as compared with five in the left, on the basis of shape, size and number of associated granulosa cells. In the parous bats, a single, nearly extroverted corpus luteum was discerned in the ovary which survived for 2-2 1/2 months. The left ovary was nearly a vestigial structure during pregnancy. The structural asymmetry of the internal genitalia was observed to be correlated with the histochemical site and pattern of distribution of acid phosphatase and alkaline phosphatase. Differential activities of phosphatases were discerned in the developing primary, secondary, preantral and antral follicles and the interstitial tissues of the contralateral ovary during the nulliparous state. A high enzyme reaction was displayed by follicles undergoing atretic and degenerative changes. In the parous bats, pronounced differences were noted in the histologic constituents of the contralateral ovary. This study shows a significant link between functional asymmetry of the genitalia and the structural and enzymological characteristics of the ovarian tissues.

Acid Phosphatase↗
PubMed1983

Spermatogenesis in the non-scrotal bat-Rhinopoma kinneari Wroughton (microchiroptera: mammalia).

Spermatogenesis in the non-scrotal, insectivorous microchiropteran, Rhinopoma kinneari Wroughton, is a cyclic phenomenon. It comprises (i) eleven cell associations, and (ii) 16 evolutive steps in spermiogenesis. In the seminiferous epithelium, spermatogonia of the A, intermediate (In), and B type are characteristically present. Leptotene, pachytene and diakinesis stages were easily discerned in dividing spermatocytes. During the 16-step spermiogenesis, the acrosomic system develops through the Golgi, cap, acrosome and maturation phases. The relative frequency of various cell associations differs markedly and is significantly at variance with other mammalian species. Fully formed spermatozoa are dimorphic with conical or blunt heads.

Animals↗
PubMed1982

Histoenzymological comparison of the prostate gland of sexually 'quiescent' and 'active' Taphozous melanopogon melanopogon Temmnick (Microchiroptera: Mammalia).

Lysosomal hydrolases (e.g., acid phosphatase, AcPase; adenosine triphosphatase, ATPase, and lipase) and the mitochondrial 'marker' enzyme succinic dehydrogenase (SDH) were evaluated histochemically in the prostate gland of sexually 'quiescent' and 'active' bats. During the former state, AcPase activity was significantly less than in sexually active animals, suggesting that prostate AcPase activity is androgen dependent. Levels of lipase activity also were highest in the prostate of sexually active bats, suggesting the importance of endogenous lipids which may be mobilized and used as a source of energy. SDH and ATPase sites and patterns of distribution in the prostate gland of bats were closely similar during the two reproductive states. Differential enzymological patterns do not seem to have any significant correlation with the morphological changes which occur in the glandular epithelium, musculature, urethra and the luminal fluid, as the animals pass from a 'quiescent' phase to one of activity and vice versa as observed in the present study.

Acid Phosphatase↗