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Biomedical subjects

B H Ali

Publications and source records attributed to B H Ali.

At least 73 records · Page 4Linked to original sources
PubMed1996

Comparative pharmacokinetics of paracetamol (acetaminophen) and its sulphate and glucuronide metabolites in desert camels and goats.

Paracetamol was administered at dosages of 5 mg/kg to camels and 10 mg/kg to goats by the intravenous and intramuscular routes. Parent paracetamol had a significantly slower clearance (21.9 +/- 1.4 mL/min.kg. vs. 52.8 +/- 7.3 mL/min.kg) (P < 0.01) in camels than in goats. In camels the predominant metabolite in plasma was the sulphate, although the ratios of glucuronide:paracetamol and sulphate:paracetamol were similar (5.20 +/- 0.50 vs. 6.59 +/- 0.51) following intravenous administration. In goats the glucuronide metabolite was the predominant moiety in plasma, and the area under the curve (AUC) of the sulphate was only 3.89% of that of the glucuronide conjugate. The apparent AUC for paracetamol in the camel following intramuscular administration was larger than that following intravenous administration, however, when the bioavailability (F) was determined, with correction for altered half-life, within the animal and between study phases it was 71 +/- 17% in goats and 105 +/- 26% in camels.

Acetaminophen↗
PubMed1996

Evaluation of the relaxant activity of some United Arab Emirates plants on intestinal smooth muscle.

Although medicinal plants are used as antispasmodic agents in folk medicine there have been no scientific studies of the phytochemical composition and usefulness of these plants for such treatment. Extracts of 23 plants used in the traditional medicine of the United Arab Emirates were tested for their effects on intestinal smooth muscle activity. Most of the plants tested caused stimulation followed by inhibition of the motility of the rabbit jejunum and guinea-pig ileum. The inhibitory effect of plants that had EC50 values < 1 mg was confirmed in-vivo using the gastrointestinal transit time test. These plants were phytochemically screened for their secondary constituents. The effect of Rhazya stricta was investigated, particularly in relation to acetylcholine effect. The results indicated the potential of some of the plants, especially Rhazya stricta, as a source of antispasmodic agents.

Acetylcholine↗
PubMed1996

Gentamicin nephrotoxicity in the rat: influence of age and diabetes mellitus.

1. This work examines the influence of age on some nephrotoxic signs of gentamicin in normal and diabetic rats (aged 1 and 24 months). 2. Gentamicin (80 mg-1 kg-1 day for 6 days, intramuscularly) produced the typical pattern of nephrotoxicity; significantly increasing the plasma concentrations of creatinine and urea, and the urinary excretion of protein, copper and zinc and significantly reducing creatinine clearance and cortical alkaline phosphatase activity. The antibiotic produced a marked damage in the proximal renal tubules. Nearly all of these effects were more marked in the old than in the young rats. Cortical gentamicin concentration in the young was about 67% of that in the old. 3. Streptozotocin-induced diabetes significantly ameliorated the signs of nephrotoxicity of gentamicin in young rats. In old rats, diabetes had significantly less protective effect on the gentamicin-induced nephrotoxic signs than in the young rats. Gentamicin nephrotoxicity in diabetic old rats induced mortality in about a third of the animals used, whereas no mortality was seen in young diabetic rats treated with gentamicin.

Aging↗
PubMed1995

Some pharmacological studies on Artemisia herba-alba (Asso.) in rabbits and mice.

The aqueous extract of Artemisia herba-alba Asso. (Compositae) produced an initial hyperglycaemia which was followed by hypoglycaemia in normoglycaemic and alloxan-treated rabbits and mice. The extract (0.39 g/kg) significantly increased gastrointestinal transit time and the reaction time to thermal stimuli but had no effect on the activity of alkaline phosphatase or concentrations of creatinine and urea in plasma. Histopathological examination indicated mild hydropic degeneration in hepatocytes and proximal convoluted tubules. The duodenum showed mild oedema of the substantia of the mucosal propria. The plant extract showed weak antimicrobial activity.

Alloxan↗
PubMed1995

The effect of L-tyrosine on some anti-nociceptive and non-nociceptive actions of morphine in mice.

1. This work examines the effect of L-tyrosine on the antinociceptive and non-nociceptive actions of morphine in mice. The antinociceptive action was measured using the hot plate method, and the non-nociceptive actions included the effect on concentrations of glucose, cholesterol and triglycerides in serum or blood, and the effect on gastrointestinal transit time (GITT) and rectal temperature. 2. L-tyrosine (25, 50, 100 and 200 mg/kg), subcutaneously (s.c.) dose-dependently potentiated the antinociceptive action of morphine (5 mg/kg, s.c.). L-tyrosine alone did not produce significant antinociceptive action, nor did it affect any of the other non-nociceptive actions measured. 3. Acute administration of morphine (5, 10 and 20 mg/kg) produced dose-dependent increases in blood glucose concentration which were insignificantly potentiated by L-tyrosine (25-200 mg/kg) when given together with morphine. Morphine produced dose-dependent and significant decrease in serum triglycerides concentrations, an effect which was not influenced by L-tyrosine treatment. Serum cholesterol was not affected by treatment with morphine, either alone or when given with L-tyrosine. 4. Morphine produced dose-dependent and significant decreases in GITT which was not affected with L-tyrosine.

Analgesia↗
PubMed1995

Effect of Teucrium stocksianum on paracetamol-induced hepatotoxicity in mice.

1. Hepatoprotective activity of an ethanolic extract of Teucrium stocksianum was investigated against paracetamol-induced hepatic damage in mice. 2. Paracetamol at an oral dose of 0.6 g/kg produced about 94% mortality in mice while pretreatment with the plant extract (0.5 and 1 g/kg for 5 days) reduced the death rate to 0%. 3. Paracetamol (0.6 g/kg, orally) produced liver damage as manifested by significant rises in liver weight, plasma aspartate aminotransferase (AST) activity and bilirubin concentration, pentobarbitone-induced sleeping time, and by the significant depletion of reduced glutathione (GSH) in the liver. 4. Pretreatment of mice with T. stocksianum at the above doses significantly ameliorated all the paracetamol-induced signs of liver damage described above. 5. T. stocksianum did not produce any lethality or adverse effects in the livers of treated mice. 6. These results indicate that T. stocksianum ethanolic extract contains hepatoprotective constituents, and suggest further work on the isolation and characterization of these constituents which may potentially be used as hepatoprotective agents.

Acetaminophen↗
PubMed1995

Gentamicin nephrotoxicity in humans and animals: some recent research.

It would appear from the literature cited in this article, that interest in gentamicin nephrotoxicity is still thriving. Despite extensive studies, the mechanism(s) of the nephrotoxicity is uncertain. Several clinical and experimental strategies have been employed in order to ameliorate or abolish the signs of gentamicin nephrotoxicity. Most of these were unsuccessful, impractical or unsafe. Therefore there is still a need for further studies to elucidate the mechanism(s) of action of the drugs nephrotoxicity, and to discover safe, practical and effective agents to ameliorate the nephrotoxicity in patients at risk.

Age Factors↗
PubMed1995

Single-dose compared with fractionated-dose radiation of the OM431 choroidal melanoma cell line.

PURPOSE: To compare single-dose and fractionated-dose radiotherapeutic effects on choroidal melanoma cells. METHODS: We determined the effects of gamma radiation on OM431 cell survival by exposing cells to either a single 9-Gy dose or two 4.5-Gy fractionated doses at intervals of 20 minutes to eight hours. The effects of single dosing and fractionated dosing at six hours were compared at doses of 2 to 12 Gy. RESULTS: Tumor cell repair was most rapid during the first two hours. Maximum repair had occurred by six hours after radiation. Cell survival curves showed doses greater than 3 Gy of single-dose gamma radiation resulted in a greater number of cells killed than did equivalent fractionated doses. CONCLUSIONS: Ocular melanoma in vitro is relatively radioresistant to low-dose fractionated radiotherapy. High single-dose radiotherapy would be more effective but would also result in more damage to normal tissue unless more focused modalities of radiotherapy are used.

Cell Survival↗
PubMed1995

Central nervous system activity of Rhazya stricta (Decne) in mice.

1. The effects of orally administered aqueous lyophilized extract of the leaves of Rhazya stricta (2, 4 & 8 g/kg) on aspects of nervous system function were investigated in mice. 2. In three antinociceptive tests (hot plate, abdominal constriction, and warm water tail flick tests), the extract exhibited dose-dependent and significant antinociceptive activity. Naloxone was ineffective in antagonizing the analgesic effect of Rhazya stricta on tail-flick and abdominal constriction tests, possibly indicating that this effect occurs via non-opiate pathways. 3.Pretreatment of mice with the xenobiotic metabolizing enzymes inhibitor cimetidine (50 mg/kg) did not significantly alter the antinociceptive action of the extract, indicating that the effect is probably due to the parent compound(s) present in the extract and not to metabolites thereof. 4. Rhazya stricta produce dose-dependent sedation, decreased motor activity, and impaired motor control. Time spent on a rotarod treadmill was significantly decreased after treatment with the extract. 5. Rhazya stricta extract (8 g/kg) produced a degree of sedation comparable to that produced by diazepam (5-10 mg/kg), and also significantly increased the reaction time of the tail-flick test, an action which was not produced by diazepam. 6. Administration of R. stricta extract potentiated pentobarbitone sleeping time in a dose dependent manner. The extract did not significantly antagonize picrotoxin induced convulsions. The extract (4 and 8 g/kg) significantly decreased the rectal temperature of normothermic and hyperthermic mice. 7. Pretreatment with R. stricta extract (8 g/kg) completely prevented the occurrence of aggressive behaviour in male mice. 8. It is concluded that the crude extract of R. stricta has central nervous system depressant properties.

Abdomen↗
PubMed1995

Sex differences and the effect of gonadectomy on morphine-induced antinociception and dependence in rats and mice.

1. Differences between sexes and the effect of bilateral surgical gonadectomy on the response to morphine analgesia and dependence were examined in rats and mice. 2. The analgesic response to morphine (5 mg/kg) was assessed by the hot plate and the abdominal constriction tests. Dependence was induced by injecting morphine at increasing doses (5-160 mg/kg) for 6 consecutive days and withdrawal signs elicited by injecting naloxone (2.5 mg/kg). 3. The base line reaction times in the intact control, sham-operated and gonadectomized animals of either sex were not significantly different from each other. 4. After treatment with morphine, the percentage increase in the reaction time in gonadectomized male and female rats and in gonadectomized male mice was significantly higher than in their respective controls. 5. The increase in the reaction time, after morphine treatment, was significantly higher in gonadectomized female rats than in gonadectomized male rats. 6. Naloxone-induced withdrawal signs in morphine-dependent gonadectomized rats and mice were not significantly different from those in sham-operated controls. However, female rats in both groups exhibited a significantly higher number of escape jumping responses than males.

Analgesia↗
PubMed1995

Anti-inflammatory, antipyretic, and analgesic effects of Lawsonia inermis L. (henna) in rats.

Crude ethanolic extract of Lawsonia inermis L. (0.25-2.0 g/kg) produced significant and dose-dependent anti-inflammatory, analgesic, and antipyretic effects in rats. The extract also produced significant increases in pentobarbitone-induced sleeping time. Using a liquid-liquid extraction procedure, the extract was fractionated into chloroform, butanol, and water fractions, and these were tested for the above activities. The butanol and chloroform fractions showed more potent anti-inflammatory, analgesic, and antipyretic effects than the crude extracts, while the aqueous extract showed significantly less effect. As compared with the other extracts, the butanolic extract (500 mg/kg) was the most effective in the analgesic test. From the chloroform extract, a pure compound was isolated and identified, using chromatographic and spectroscopic techniques, as 2-hydroxy-1,4-naphthaquinone (lawsone). The isolated compound was found to possess significant anti-inflammatory, analgesic, and antipyretic activity. It potentiated significantly the pentobarbitone-induced sleeping time. The anti-inflammatory effect of lawsone (500 mg/kg) was not significantly different from that of the reference drug phenylbutazone (100 mg/kg).

1-Butanol↗
PubMed1995

The effect of thyroxine or carbimazole treatment on gentamicin nephrotoxicity in rats.

1. This study examines the effect of treating rats with gentamicin (80 mg kg-1 day-1 intramuscularly (i.m.), for 6 days) alone or with either L-thyroxine or the anti-thyroid drug carbimazole. 2. Gentamicin produced significant increases in serum creatinine and urea concentrations, and significantly reduced the activity of Na+,K+ATPase in renal cortex. The concentration of serum triiodothyronine (T3) was unaffected by graded doses (20, 40 and 80 mg kg-1) of the antibiotic. Histopathologically, gentamicin produced necrosis of proximal tubules in the renal cortical tissues of treated rats. 3. Treatment of rats with either L-thyroxine or carbimazole alone did not significantly affect any of the biochemical variables investigated. Carbimazole alone produced only mild tubular necrosis. 4. Treatment of rats with either L-thyroxine (100 micrograms kg-1 day-1, subcutaneously) for 10 days, and gentamicin (80 mg kg-1, i.m. daily during the last 6 days of treatment significantly reduced the gentamicin-induced increases in serum creatinine and urea concentrations, and increased the activity of cortical N+,K+ATPase to control levels. Histopathologically, the severity of gentamicin-induced tubular necrosis was reduced by L-thyroxine treatment. 5. Carbimazole (12 mg ml-1 in drinking water for 21 days) and gentamicin (80 mg kg-1 i.m.) daily during the last 6 days of treatment, stimulated the increase in serum urea concentration produced by gentamicin, but did not significantly affect the gentamicin-induced changes in serum creatinine or cortical N+,K+ATPase.

Animals↗
PubMed1994

Progression of retinal nerve fiber myelination in childhood.

Myelination of the visual pathway has been demonstrated to occur by as early as 32 weeks of gestation and continues for several years into early childhood. In most cases, the process of myelination does not extend beyond the lamina cribrosa. We studied a boy with progressive myelination that extended beyond the lamina cribrosa to the retinal nerve fibers. Ocular examination at 15 months of age disclosed myelinated optic nerve fibers of the right eye. We repeated examination every two to six months and found progression of the extent and density of the myelinated nerve fibers. Despite the marked myelination, the patient did not experience a decrease in visual acuity.

Follow-Up Studies↗
PubMed1994

Effect of gentamicin-induced nephrotoxicity on some carbohydrate metabolic pathways in the rat renal cortex.

Rats were injected with gentamicin at doses of 20, 40 and 80 mg/kg per day for 6 consecutive days. The treatment caused nephrotoxicity as evidenced by dose-related increases in serum creatinine concentration and renal tubular necrosis. The nephrotoxicity was accompanied by reduced renal cortical and fasting blood glucose levels, and by increases in serum lactate concentrations. The activities of cortical malate dehydrogenase and alanine transaminase were significantly reduced by the three doses of gentamicin. On the other hand, aspartate transaminase activity was lowered only by the highest dose of antibiotic used. However, the activity of cortical glucose-6-phosphate dehydrogenase was altered by the 20 and 40 mg/kg doses of gentamicin, but not by the 80 mg/kg dose. The two lower doses reduced the lactate content of the cortex but activated lactate dehydrogenase. The activity of isocitrate dehydrogenase was not altered by any of the gentamicin doses used.

Alanine Transaminase↗
PubMed1994

Effect of grapefruit juice on drug metabolism in rats.

The effect of grapefruit juice on in vivo drug metabolism was investigated in rats. The juice (4 ml or 8 ml/kg) was given orally once daily for 2 consecutive days and its effect on theophylline metabolism, pentobarbitone sleeping time and the tremorgenic action of tremorine was studied. The effect of grapefruit juice on some of these parameters was compared with that of the known drug metabolism inhibitor cimetidine given ip. Grapefruit juice at 4 ml and 8 ml/kg produced significant increases in pentobarbitone sleeping time that reached 46 and 79%, respectively, compared with 107% produced by cimetidine (50 mg/kg, ip). The juice at 4 ml/kg also significantly increased plasma theophylline concentration when measured 15, 30, 60 and 90 min after ip theophylline administration (10 mg/kg). Thereafter, no significant differences were detected in plasma drug concentrations between juice- and saline-treated animals. Administration of tremorine (25 mg/kg, ip) to saline-treated controls produced, within 2 or 3 min, tremors, piloerection, profuse salivation, defaecation, urination and chromodacryorrhesis (red tears). The onset of appearance of these signs was delayed to about 7 min in rats pretreated 1 hr earlier with either grapefruit juice (4 ml/kg, orally) or cimetidine (50 mg/kg, ip). The severity of the above signs was markedly reduced to a similar extent in both the juice- and cimetidine-treated rats. These results suggest that grapefruit juice may act as an inhibitor of drug metabolism in rats, and that its consumption may alter the disposition of certain concomitantly administered drugs.

Animals↗
PubMed1994

Influence of iron, deferoxamine and ascorbic acid on gentamicin-induced nephrotoxicity in rats.

1. Nephrotoxicity was induced in rats by injecting gentamicin intramuscularly (i.m.) at a dose of 80 mg/kg for 6 days. Treated animals demonstrated a typical pattern of nephrotoxicity characterized by increased serum creatinine and urea concentrations, and by necrosis of proximal tubular epithelium. 2. Pretreatment of rats with iron (Fe3+) at daily i.m. doses of 2, 4 and 8 mg/kg for 14 days, with gentamicin given during the last 6 days of treatment, significantly potentiated the gentamicin-induced increases in creatinine and urea concentrations and exacerbated renal histological damage. 3. Gentamicin significantly increased serum Fe3+ concentration in rats treated with Fe3+ and gentamicin, compared to Fe(3+)-treated rats. 4. The Fe3+ antidote deferoxamine (100 mg/kg, i.m.) given with gentamicin was ineffective in antagonizing the potentiating effect of Fe3+ on gentamicin-induced nephrotoxicity. 5. Ascorbic acid (50 mg/kg, i.m. for 14 days) was ineffective in altering the nephrotoxicity of gentamicin (80 mg/kg) given during the last 6 days of treatment. At a dose of 100 mg/kg for 14 days, ascorbic acid significantly reduced gentamicin-induced increases in creatinine and urea levels, and ameliorated proximal tubular damage. However, at a dose of 200 mg/kg, ascorbic acid exacerbated gentamicin-induced increases in creatinine and urea levels and increased the severity of the histological damage.

Animals↗