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Biomedical subjects

A Suria

Publications and source records attributed to A Suria.

At least 19 recordsLinked to original sources
PubMed2003

Optimization of making barrel-fermented dry muscatel wines.

The optimization of making barrel-fermented muscatel wines requires determining what type of must clarification is most suitable for the quality of the wine, as well as what type of barrel will yield the most acceptable wines. This is achieved by adding pectolytic enzymes to clarify part of the muscatel must statically; the rest is clarified by vacuum filtration. The musts obtained are fermented in French and American oak barrels and, once fermentation has ceased, they are kept with their lees for 2 months, with periodic stirring. Eleven conventional parameters and 31 volatile compounds were quantified, and a sensory analysis of the wines was produced, which led us to conclude that static clarification with pectolytic enzymes from the muscatel musts produces the best-structured wines and the larger content of higher alcohols, esters, and terpenic compounds. The wines fermented in American oak barrels received the highest overall marks, which may be due to the greater aromatic complexity given off by the compounds in the wood.

Alcohols↗
PubMed2001

Anticonvulsant activities of the FS-1 subfraction isolated from roots of Delphinium denudatum.

Delphinium denudatum Wall. (Ranunculaceae) is a medicinal herb used for the treatment of epilepsy in the subcontinent. The present study reports the anticonvulsant activities in the maximal electroshock test (MEST) and subcutaneous pentylenetetrazole (PTZ), bicuculline (BIC), picrotoxin (PIC)-induced seizures of the FS-1 subfraction (FS-1) that was obtained by purification of an aqueous fraction isolated from the roots of D. denudatum. In CF 1 mice, FS-1 (600 mg/kg i.p.) exhibited very potent anticonvulsant activity that was comparable to the effects of the well-known antiepileptic drug phenytoin (20 mg/kg) in MEST and protected 100% animals from hind limb tonic extension phase of this model. FS-1 also suppressed PTZ-induced threshold seizure and the loss of the righting reflex with tonic fore and hind limb extension by 100%, similar to the antiepileptic drug valproic acid (350 mg/kg). BIC-induced seizures were suppressed in 80% of the animals. FS-1 exhibited weak anticonvulsant effect on PIC-induced seizures, however, it significantly reduced mortality and delayed the onset of seizures. FS-1 had no effect on strychnine (STN)-induced extensor seizures. The results demonstrate the broad and potent anticonvulsant activity of the compounds in FS-1 of D. denudatum.

Animals↗
PubMed2001

Anticonvulsant activities of ethanolic extract and aqueous fraction isolated from Delphinium denudatum.

Dried roots of Delphinium denudatum Wall. are a popular folk remedy for the treatment of epilepsy in the traditional Unani system of medicine in the sub-continent. We carried out anticonvulsant screening of the ethanolic extract (EE) and aqueous fraction (AF) of this plant utilising the maximal electroshock (MEST) and subcutaneous pentylenetetrazole (scPTZ), bicuculline (scBIC), picrotoxin (scPTX) and strychnine (scSTN) tests for anticonvulsant activity. EE had weak dose-dependent anticonvulsant effects on seizures induced by PTZ and BIC. AF exhibited dose-dependent activity against hind limb tonic extension phase (HLTE) of MEST and comparatively stronger anticonvulsant activity against seizures induced by PTZ and BIC. The results suggest the presence of potent anticonvulsant compounds in AF of D. denudatum and deserve further investigation for isolation of active compounds and elucidation of the mechanism of anticonvulsant action.

Animals↗
PubMed1999

Bio-active cardenolides from the leaves of Nerium oleander.

A bioactivity directed isolation of the methanolic extract of the fresh, uncrushed leaves of Nerium oleander showing a central nervous system (CNS) depressant effect in mice has been undertaken. As a result, four CNS depressant cardenolides including a new cardenolide, neridiginoside and three known constituents, nerizoside, neritaloside and odoroside-H, have been isolated which exhibited CNS depressant activity in mice at a dose of 25 mg/kg. The structure of neridiginoside was elucidated as 3 beta-O-(D-diginosyl)-5 beta, 14 beta-dihydroxy-card-20(22)-enolide, using spectroscopic methods including one-dimensional and two-dimensional NMR (COSY-45, NOESY, J-resolved, HMQC and HMBC). The known compounds have been indentified through spectral studies and comparison of data with those reported in the literature.

Animals↗
PubMed1998

Vitamin D status of breastfed Pakistani infants.

This study was conducted to evaluate the vitamin D status of healthy breastfed Pakistani infants and their nursing mothers. Sixty-two breastfed healthy infants and their nursing mothers belonging to the upper and lower socioeconomic classes were examined. Serum 25-hydroxy vitamin D [25(OH)D], serum calcium, phosphorus and alkaline phosphatase were measured. The mean serum 25(OH)D in infants was 34.59 +/- 26.56 nmol/l. Fifty-five percent of infants and 45% of mothers had very low serum 25(OH)D levels (<25 nmol/l). Significantly higher levels were found in infants of lower socioeconomic class (p < 0.001) and in those living in mud houses (p = 0.002) and infants >6 months (p < 0.001). A high prevalence of vitamin D deficiency was found in breastfed infants and nursing mothers, predominantly among those belonging to the upper socioeconomic class. Infants of the lower socioeconomic class had comparatively higher serum 25(OH)D levels, but even these levels were below the normal range for infants (90 +/- 27.5 nmol/l).

Alkaline Phosphatase↗
PubMed1998

Maternal vitamin-D deficiency in Pakistan.

OBJECTIVE OF THE STUDY: This study was performed to assess the vitamin D status of healthy Pakistani nursing mothers and their breastfed infants. METHODS: Seventy-one nursing mothers and their breastfed infants belonging to upper and lower socio-economic class were examined 6 weeks to 11 months after delivery. Serum 25-hydroxy vitamin D [25(OH)D], serum calcium, phosphorus and alkaline phosphatase were measured. RESULTS: The mean serum 25(OH)D in mothers was 36.7+/-32.4 nmol/L and 41.25+/-35.4 nmol/ L in infants. Thirty-four (48%) mothers and 37 (52%) infants had levels less than 25 nmol/ L. Significantly higher levels were found in uneducated mothers (p=0.01), mothers of lower socio-economic class (p<0.001) and in those living in mud houses (p<0.001). A significant correlation was found between serum 25(OH)D levels of infants under three months of age and their mothers (p<0.01). CONCLUSIONS: High prevalence of vitamin D deficiency was found in nursing mothers and their infants predominantly in the upper socioeconomic class.

Adult↗
PubMed1997

Cardenolides from the methanolic extract of Nerium oleander leaves possessing central nervous system depressant activity in mice.

Two new cardenolides, 3 beta-O-(D-2-O-methyldigitalosyl)-14 beta-hydroxy-5 beta-carda-16,20(22)-dienolide (1) and 3 beta-hydroxy-8,14-epoxy-5 beta-carda-16,20(22)-dienolide (2), and two known cardenolides, 3 beta-O-(D-digitalosyl)-14 beta-hydroxy-16 beta-acetoxy-5 beta-card-20(22)-enolide (3) and 3 beta-O-(D-digitalosyl)-14 beta-hydroxy-5 beta-card-20(22)-enolide (4), have been isolated from the leaves of Nerium oleander following a bioactivity-directed isolation of the MeOH extract, which showed central nervous system (CNS) depressant activity in mice at a dosage of 50 mg/kg i.p. Their structures were established on the basis of chemical and spectral data. Compounds 1, 3, and 4 were found to exhibit sedation in mice at a dosage of 25 mg/kg, although 2 had no effect on the CNS of mice at a dosage of up to 50 mg/kg.

Animals↗
PubMed1995

Studies on the constituents of the leaves of Nerium oleander on behavior pattern in mice.

Fresh, undried and uncrushed leaves of Nerium oleander were subjected to methanol extraction and bioassay directed fractionation. This led to the isolation of two purified fractions namely, B-1 and B-3. Fractions B-1 and B-3 were studied with respect to their actions on the central nervous system and behavior pattern in mice. Both fractions were found to produce reduction in locomotor activity, rota rod performance and potentiation of hexobarbital sleeping time. These fractions also showed analgesic activity. When tested against picrotoxin induced convulsions fraction B-1 showed 40% protection, while fraction B-3 exhibited 60% protection against bicuculline induced convulsions. These findings suggest that both fractions possess a CNS depressant action.

Animals↗
PubMed1994

Evidence for involvement of amino acid neurotransmitters in anesthesia and naloxone induced reversal of respiratory paralysis.

General anesthetics render a person unconscious and may produce respiratory paralysis at therapeutic doses. No pharmacological agent is available to restore respiration and the mechanism/s of anesthesia or apnea is not clearly understood. In this report, we present evidence to show that naloxone reversed respiratory failure induced by thiopental, ketamine, halothane but not that induced by phenobarbital. Furthermore, 25 mg/kg, i.v. thiopental, 140 mg/kg, i.v. ketamine, and 3% halothane produced anesthesia without significantly altering respiratory rate, increased GABA and decreased glutamate (except ketamine and phenobarbital) levels in rat brain stem and cortex, but not in caudate and cerebellum. Aspartate, glycine and alanine levels were not affected in four brain regions studied. Pretreatment with TSC for 30 minutes did not change GABA or glutamate contents, but abolished the anesthetic as well as the respiratory depressant actions of the anesthetics. Increasing the doses of anesthetics produced respiratory failure with further rise in GABA and fall in glutamate in brain stem and cortex. Naloxone reversed respiratory paralysis and restored GABA close to control values in rat brain stem and cortex with no changes in caudate or cerebellum. Data presented here suggest that GABA may be necessary to produce loss of consciousness and naloxone reverses anesthetic induced respiratory failure.

Anesthesia↗
PubMed1994

Possible presence of calcium channel blocker(s) in Rubia cordifolia: an indigenous medicinal plant.

Crude extract of Rubia cordifolia (RC) was tested in isolated tissue preparations for its possible calcium channel antagonistic activity. RC suppressed the spontaneous contractions of guinea-pig atria, rabbit jejunum and rat uterus in a concentration dependent manner (0.1-3 mg/ml). In rabbit aorta, it inhibited norepinephrine (10 microM) and KCl (80 mM) induced contractions. Replacement of physiological salt solution with calcium free solution abolished the spontaneous movements of rabbit jejunum. However, addition of calcium (25 micrograms/ml) in the tissue bath restored the spontaneous movements. When the tissues were pretreated with plant extract (1 mg/ml) or verapamil (0.5 microgram/ml), addition of calcium failed to restore spontaneous contractions. These results indicate that the plant extract exhibits spasmolytic activity similar to that of verapamil suggestive of presence of calcium channel blocker like constituent(s) in this plant.

Animals↗
PubMed1993

Vitamin A status of children in the urban slums of Karachi, Pakistan, assessed by clinical, dietary, and biochemical methods.

We assessed the vitamin A status of 532 children with an age range of 6-60 months who were living in slum areas of Karachi, Pakistan, using three methodologies: clinical eye examination, dietary vitamin A intake, and serum retinol level. No definite clinical signs of xerophthalmia were observed in any of these children. The mean +/- SD vitamin A intake estimated from a food frequency questionnaire for the group with inadequate (low and deficient) serum retinol levels (< 20 micrograms/dl) was 362 +/- 332 retinol equivalents (RE) compared with 431 +/- 332) RE in the group with adequate serum levels (P < 0.005). Deficient serum retinol levels (< 10 micrograms/dl) were present in 12 children (2%); two of these had a healed corneal scar. Low serum retinol levels (10-19 micrograms/dl) were present in 46%, while 51% children had adequate levels (> or = 20 micrograms/dl). The mean +/- SD serum retinol level for the inadequate (< 20 micrograms/dl) and adequate groups were 15.3 +/- 2.8 and 26.6 +/- 6.7 micrograms/dl, respectively. These results suggest that a significant number of children in these communities have low vitamin A levels and thus may constitute an at risk group. These results also suggest that the dietary intake method may be a simple and inexpensive screening tool for assessment of vitamin A status in communities.

Anthropometry↗
PubMed1991

Chloramphenicol therapy of typhoid fever.

In a prospective study we compared two different dosage regimens of IV chloramphenicol succinate (100 mg/kg/day and 75 mg/kg/day) in children with culture proven typhoid. Trough and peak blood samples, obtained at 48 hrs, were analysed for free chloramphenicol by high pressure liquid chromatography (HPLC). Although the mean trough (8.8 +/- 7.7 versus 5.4 +/- 2.6 mcg/ml) and peak (19.9 +/- 12.2 versus 15.4 +/- 6.1 mcg/ml) chloramphenicol concentrations were comparable in both groups, a significantly wider range was found in the group receiving 100 mg/kg/day. Potentially toxic levels (greater than 30 mcg/ml) developed in two patients with liver dysfunction. Chloramphenicol in a dosage of 75 mg/kg/day is adequate and safe for the treatment of paediatric typhoid.

Adolescent↗
PubMed1988

GABA involvement in naloxone induced reversal of respiratory paralysis produced by thiopental.

No agent is yet available to reverse respiratory paralysis produced by CNS depressants, such as general anesthetics. In this study naloxone reversed respiratory paralysis induced by thiopental in rats. 25 mg/kg, i.v. thiopental produced anesthesia without altering respiratory rate, increased GABA, decreased glutamate, and had no effect on aspartate or glycine levels compared to controls in rat cortex and brain stem. Pretreatment of rats with thiosemicarbazide for 30 minutes abolished the anesthetic action as well as the respiratory depressant action of thiopental. 50 mg/kg, i.v. thiopental produced respiratory arrest with further increase in GABA and decrease in glutamate again in cortex and brain stem without affecting any of the amino acids studied in four regions of rat brain. Naloxone (2.5 mg/kg, i.v.) reversed respiratory paralysis, glutamate and GABA levels to control values in brain stem and cortex with no changes in caudate or cerebellum. These data suggest naloxone reverses respiratory paralysis produced by thiopental and involves GABA in its action.

Animals↗
PubMed1988

Differential effects of dimethyl sulfoxide on human platelet aggregation and arachidonic acid metabolism.

DMSO inhibited human platelet aggregation induced by ADP, AA, PAF, or collagen in a concentration-related manner, in vitro. DMSO was a more effective inhibitor for aggregation induced by ADP and collagen than PAF or AA. However, in vivo experiments on rabbits showed that DMSO did not protect rabbits against death from pulmonary platelet thrombosis induced by AA. On the other hand, DMSO (1-30% v/v) had no effect on thromboxane production by platelets incubated with [14C]AA. Moreover, DMSO stimulated PGE2 production by bovine seminal vesicle PG synthase. DMSO also stimulated the production of 12-HETE but inhibited the production of tri-HETE produced via lipoxygenase pathway. Since lipoxygenase products play an important role in inflammation, our data suggest that the anti-inflammatory effects of DMSO are probably not mediated via its action on AA metabolism.

Animals↗
PubMed1987

Ability of human plasma to inhibit prostaglandin F2 alpha in asthma.

Human plasma has been reported to inhibit the conversion of arachidonic acid into prostaglandin (PG) E2 and PGF2 alpha. In the present study the plasma inhibitory activity was determined in three groups (16 each) of plasma obtained from normal healthy volunteers, treated asthmatics and untreated asthmatic patients. The result showed that plasma from all three groups were equally effective in inhibiting the biosynthesis of PGE2. Plasma of normal volunteers and treated asthmatics also inhibited PGF2 alpha biosynthesis. In contrast the plasma obtained from untreated asthmatics was considerably less active in inhibiting the biosynthesis of PGF2 alpha than plasma from the other two groups.

Asthma↗