Search PubMed⌕ Search

Biomedical subjects

A T Ali

Publications and source records attributed to A T Ali.

26 records · Page 2Linked to original sources

Cyclosporin-A inhibits accumulation of lymphocytes within lymph nodes.

The ability of cyclosporin-A (CS-A) to modify lymphocyte accumulation, seen in lymph nodes draining a site of antigen deposition, has been compared with the effect of other drugs known to affect lymphocytes and/or macrophages. CS-A markedly inhibited lymphocyte accumulation in a dose-related manner, whereas aspirin, BW755c (3 amino 1 [m (trifluoromethyl) phenyl] 2-pyrazoline) and hydrocortisone were without effect. Indomethacin produced inconclusive results. The time of CS-A administration was critical, the drug needing to be present before antigen inoculation, being ineffective if given 23 hr after antigen.

Animals↗

Bacterial keratitis after photorefractive keratectomy.

Two patients who had excimer laser photorefractive keratectomy (PRK) for myopia developed bacterial keratitis, one from Staphylococcus epidermidis and the other with a negative culture. Both were treated with topical antimicrobial agents. One eye recovered an uncorrected visual acuity of 20/20. The other was left with a moderate subepithelial scar and an uncorrected visual acuity of 20/150.

Adult↗

Gastric protection against cold restraint stress-induced lesions by amoxycillin in rats.

AIMS: Recent investigations have shown that amoxycillin possesses gastric protection properties in addition to its known antimicrobial effects. Therefore, this study was undertaken to investigate the potential gastric protection effects of amoxycillin and to determine its possible mechanism(s) of action in rats. METHODS: The cold restraint stress model was used to produce gastric mucosal lesions. The gastric secretion studies were undertaken by using Shay's pylorus ligation technique. The antioxidant effect was studied by luminol dependent chemiluminescence technique in vitro. RESULTS: Amoxycillin dose-dependently prevented cold restraint stress-induced mucus depletion and afforded protection. It inhibited indomethacin-stimulated gastric acid secretion with a high dose without affecting basal secretion. Furthermore, amoxycillin dose-dependently inhibited the phorbol myristate acetate-stimulated luminol-dependent chemiluminescence responses of isolated human poylmorphonuclear leukocytes in vitro. CONCLUSIONS: These results suggest that mechanisms of gastric protection effects of amoxycillin may include inhibition of stimulated acid secretion, prevention of depletion of mucus and antioxidant properties.

Amoxicillin↗

Inhibitory effect of natural honey on Helicobacter pylori.

Honey is widely used in folk-medicine throughout the world. However, it has a limited use in modern medicine due to lack of scientific support. Based on some recent reports, an in vitro study was undertaken to evaluate its antibacterial activity on Helicobacter pylori and a few other pathogenic organisms. All isolates of H. pylori were inhibited by 20 per cent of honey. Most of the other bacteria examined (including both Gram-positive and Gram-negative) were also inhibited at concentrations of 20 per cent of honey; and half of them were inhibited by 10 per cent of honey. Furthermore, it was observed that some isolates were resistant to various antimicrobial agents but honey inhibited these organisms and the sensitive ones equally. Our study advocates carrying out clinical investigation of the effect of honey on gastroduodenal disorders colonised by H. pylori.

Culture Media↗

Cardiomyoplasty: hemodynamic benefit to normal and depressed canine left ventricular function.

This study examined the effects of cardiomyoplasty with vascular delay on canine normal and depressed left ventricular (LV) function. To improve viability of the latissimus dorsi muscle (LDM), vascular delay was performed 2 weeks before cardiomyoplasty in 10 mongrel dogs. Two weeks after cardiomyoplasty, LV function was evaluated by simultaneously measuring LV and aortic pressure, and aortic flow. The LDM was stimulated at a ratio of 1:4-1:7 synchronously with ventricular systole. Microspheres (90 mu) were sequentially injected into the left coronary artery to depress LV function. Data were acquired and analyzed on a beat to beat basis. Results were as follows: LDM stimulation significantly augmented LV systolic pressure (LVSP) from 138 +/- 2 to 161 +/- 2* mmHg, the peak rate of change of LV pressure (+dP/dt) from 1888 +/- 46 to 2584 +/- 43* mmHg/sec, aortic systolic pressure (AoSP) from 140 +/- 2 to 159 +/- 2* mmHg, stroke volume (SV) from 11.2 +/- 0.3 to 13.3 +/- 0.3* ml, stroke work (SW) from 19 +/- 1 to 26 +/- 1* gm.m, peak aortic flow (P Qa) from 5542 +/- 142 to 7190 +/- 161* ml/min, and decreased -dP/dt from -1683 +/- 31 to -1689 +/- 49* mmHg/sec (* = p < 0.05). Microsphere injections depressed LV function, but did not affect the magnitude of the net changes between stimulated and nonstimulated beats. However, the percent changes significantly increased. Preconditioning of LDM with vascular delay augments cardiac function in LDM assisted beats. This improved performance was present in both normal as well as depressed LV function groups. Thus, investigations of cardiomyoplasty may not necessarily require a model of severe myocardial dysfunction. Vascular delay offers an important preconditioning method of LDM to augment cardiac function in cardiomyoplasty.

Animals↗

Effect of ablation of capsaicin-sensitive neurons on gastric protection by honey and sucralfate.

BACKGROUND/AIMS: Accumulating evidence indicates that capsaicin-sensitive afferent neurons play a pivotal role in acute gastroprotection by liberating vasodilator substances. The mechanism of gastric protection by honey and sucralfate has been shown to be mediated through the vasodilator nitric oxide and cytoprotective sulphydryl-sensitive pathways in the stomach. The aim of the present study was to investigate the role of capsaicin-sensitive afferent neurons in the protective mechanism of honey and sucralfate against ethanol-induced gastric lesions. METHODOLOGY: Ablation of capsaicin-sensitive afferent neurons was carried out by treating rats with neurotoxic doses of capsaicin (50 + 50 mg/kg subcutaneously over 2 consecutive days). The control groups received equal volumes of the vehicle (10% ethanol + 10% Tween 80 + 80% normal saline). The non-protein sulphydryl level was determined spectrophotometrically. RESULTS: Afferent sensory nerve ablation significantly aggravated ethanol-induced gastric lesions and caused a greater depletion of non-protein sulphydryl levels. Pretreatment with honey (0.078-0.625 g/kg, orally) or sucralfate (0.062-0.250 g/kg, orally) 30 min before administration of the ethanol prevented ethanol-induced gastric lesions and the depletion of non-protein sulphydryls in vehicle-treated rats. However, honey failed to afford protection or reverse non-protein sulphydryl depletion, while sucralfate was effective in the capsaicin-treated animals. The protective effect of sucralfate was lost in both groups following pretreatment with indomethacin (10 mg/kg, subcutaneously), while honey-induced protection was unaffected. CONCLUSIONS: These results suggest that the gastric protection by honey is solely dependent on the presence of intact afferent sensory neurons, whereas sucralfate-induced gastroprotection is mediated through the afferent sensory neuron and prostaglandin systems. It seems that the non-protein sulphydryl level is affected by the ablation of sensory neurons and plays an important regulatory role in gastric protection.

Animals↗