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Biomedical subjects

N A Ali

Publications and source records attributed to N A Ali.

10 recordsLinked to original sources

Screening of Yemeni medicinal plants for antibacterial and cytotoxic activities.

Ethanolic extracts of 20 selected plant species used by Yemeni traditional healers to treat infectious diseases were screened for their antibacterial activity against both Gram-positive and Gram-negative bacteria, as well as for cytotoxic activity. Fourteen of the ethanolic extracts showed variable degrees of antibacterial activity. The active ethanolic extracts were partitioned between ethyl acetate and water for a first separation. The ethyl acetate extract of Lawsonia inermis was found to be the most active one against all bacteria in the test system. Other promising results could be obtained from extracts of Aloe perryi, Indigofera oblongifolia, Meriandra benghalensis and Ziziphus spina christi. Additionally, the ethanolic extracts of the 20 plants under investigation were tested for their cytotoxic effects on FL-cells using the neutral red assay. Extracts of Calotropis procera, Chenopodium murale, Pulicaria orientalis, Tribulus terrestris and Withania somniferum displayed a remarkable activity.

Anti-Bacterial Agents↗

Haemolytic potential of three chemotherapeutic agents and aspirin in glucose-6-phosphate dehydrogenase deficiency.

The potential haemolytic effect of three chemotherapeutic drugs and aspirin was tested in vitro by gluthathione stability tests. Blood was collected from the local population of Basra, Iraq where previous studies had found a high frequency of glucose-6-phosphate dehydrogenase (G6PD) deficiency. Primaquine, chloramphenicol and sulfanilamide caused significant concentration-dependent reductions of glutathione levels in G6PD-deficient red cells when compared to normal red cells. Acetylsalicylic acid had no effect on glutathione level. The G6PD-deficient erythrocytes behaved as previously reported, probably due to similar patterns in the distribution of its variants. Studies on each local variant are warranted and new drugs should be tested for haemolytic potential prior to their introduction in areas where the deficiency is common.

Anti-Bacterial Agents↗

Inhibition of chemiluminescence response of human mononuclear cells and suppression of mitogen-induced proliferation of spleen lymphocytes of mice by hispolon and hispidin.

The effects of two phenolic compounds, hispolon and hispidin isolated from fruit bodies of the basidiomycete Inonotus hispidus (Bull. ex Fr.) Karst, were investigated on the chemiluminescence response by LPS- or zymosan-activated human mononuclear cells (MNC) and on the concanavalin A-induced proliferation of spleen lymphocytes of mouse in vitro. Both compounds showed inhibitory activity in the chemiluminescence-test with an IC50 (the concentration of test compound causing 50% effect) ranging from 4.4 to 4.6 micrograms/ml (20.3 to 21.2 microM) for hispolon and < 0.1 to 1.5 micrograms/ml (from < 0.4 microM to 6.0 microM) for hispidin. Antiproliferative effects have been achieved in the lymphocyte transformation test (LTT) by hispolon with an IC50 of 3.4 micrograms/ml (15.5 microM).

Animals↗

Oxacillin-hydrolysing beta-lactamases. A comparative analysis at nucleotide and amino acid sequence levels.

We have extended the sequence of the OXA-2 beta-lactamase which together with S1 mapping has enabled us to identify the promoter site for this gene. This lies in a region that is found upstream from a variety of resistance genes on different plasmids; each gene appears to have been inserted at the same specific site and to be expressed from the same promoter. The ancestral plasmid thus appears to function as a natural expression vector. The sequence of the recombination site at the 5' end of the OXA-2 gene shows a marked similarity with the attP sequence of lambda. DNA-probe analysis confirmed that the OXA-2 and OXA-3 beta-lactamases are related, and indicated no similarity with other beta-lactamase genes. However, a comparison of amino acid sequences demonstrates that the OXA-2, OXA-1 and PSE-2 beta-lactamases show some similarities to the typical class A enzymes, especially in the central helical domain of the latter, which is largely responsible for forming the active site of the enzyme. The three oxacillinases also show marked amino acid sequence similarity with the product of a regulatory gene, blaR1, required for beta-lactamase induction in Bacillus licheniformis.

Amino Acid Sequence↗

Comparison of the effects of therapeutic doses of meptazinol and a dextropropoxyphene/paracetamol mixture alone and in combination with ethanol on ventilatory function and saccadic eye movements.

The respiratory and psychomotor effects of a single oral dose of meptazinol (200 mg) and dextropropoxyphene (65 mg)/paracetamol (650 mg) mixture, was compared alone and in combination with ethanol (0.8 g kg-1). Peak saccade velocity following meptazinol or the dextropropoxyphene/paracetamol mixture was not significantly different from placebo. When each of the treatments was followed by ethanol administration, a significant decrease in saccade velocity (P less than 0.01) was seen. Given alone, neither of the analgesic drugs produced a significant change in the slope of the ventilatory response to hypercapnia. Ethanol did not affect the ventilatory response to hypercapnia when given alone or in combination with meptazinol, but when given with the dextropropoxyphene/paracetamol mixture, a significant reduction in the slope of the ventilatory response to hypercapnia occurred at 1.5 h (P less than 0.05) and 2 h (P less than 0.01) after administration of the analgesic drug. No pharmacokinetic interaction was demonstrated between ethanol and meptazinol or the dextropropoxyphene/paracetamol mixture in the doses used. In contrast to meptazinol, the dextropropoxyphene/paracetamol mixture interacts with ethanol on the ventilatory function.

Acetaminophen↗

Radical cure of pilonidal sinus by a transposition rhomboid flap.

A new operation for pilonidal sinus is described. This utilizes a rhomboid transposition flap to cover the defect left after radical excision. The results show healing by first intention in 29 out of 30 patients. No patient remained in hospital for more than ten days. Minor infection took place in five cases and major infection in one case. Patients have been followed for up to three years. No recurrence has yet been encountered. The reasons for the success of this operation are discussed.

Adult↗