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Biomedical subjects

A Kamal

Publications and source records attributed to A Kamal.

At least 73 records · Page 4Linked to original sources
PubMed1995

Synthesis of podophyllotoxin congeners as potential DNA topoisomerase II inhibitors.

We have synthesized a number of new podophyllotoxin congeners in which the A-ring is opened and the C-ring is aromatic. These are based on the chemically modified structures of the naturally occurring podophyllum lignan, diphyllin. These have been synthesized by employing the Michael Initiated Ring Closure methodology. These lignans exhibited considerable DNA topoisomerase II inhibition and were devoid of topoisomerase I inhibition; they did not exhibit very significant activities in the in vitro human tumour cell lines assay. The results obtained provide insights into the structure-activity relationships and the design of chemically modified podophyllotoxin congeners useful in cancer chemotherapy.

Animals↗
PubMed1994

Posture entrainment as a test for autonomic function in health and disease.

Estimation of power spectra and coherence of heart rate variability signal (HRV) as well as respiration and peripheral blood flow (PBF) signals for normal subjects and diabetes using posture entrainment (standing position) are presented. Comparison of power and coherence spectra between each group leads to indices which may be helpful in the quantification of autonomic assessment of autonomic nervous system in health and disease.

Autonomic Nervous System↗
PubMed1993

Noninvasive technique for measuring and assessing the autonomic function in man using kernel method.

Estimation of the second order kernel of Volterra series in man was used to measure, assess, examine and compare the autonomic nervous system function. Description of respiratory entrainment device and experimental procedure as well as theoritical analysis of the algorithm used for estimation are presented. The paper suggests new noninvasive technique to measure and assess the autonomic function which may be valuable for many diseased people such as diabetes.

Adult↗
PubMed1993

Haematocrit values in ischaemic heart disease.

Haemoglobin (g/dl) and haematocrit (%) values were determined in 30 healthy controls and 40 patients with ischaemic heart disease. Both groups were non-smokers. Haemoglobin and haematocrit values (mean +/- SE) in patients were 15.65 +/- 0.18 and 46.45 +/- 0.49 and in controls 14.30 +/- 0.14 and 41.50 +/- 0.23. Significantly higher (P < 0.001) haematocrit value by influencing the blood viscosity may impose extra burden on the ischaemic heart.

Hematocrit↗
PubMed1990

Metabolism of ethyl 2-carbamoyloxybenzoate (4003/2), a prodrug of salicylic acid, carsalam and salicylamide.

The metabolites of 4003/2 observed in vivo have been produced by incubation in vitro of 4003/2 with liver post-mitochondrial supernatants from rat, rabbit and dog. The metabolites were characterized by UV, i.r., NMR, MS and HPLC. All the metabolites detected have been or are in use as drugs for the relief of pain and inflammation. Hence, the new drug 4003/2 is a pro-drug of salicylic acid, carsalam and salicylamide.

Animals↗
PubMed1990

Renal papillary necrosis in the east coast of Peninsular Malaysia.

Six hundred and one intravenous Urograms (IVU) done at the General Hospital, Kuala Trengganu from 1981 to 1985 were reviewed retrospectively for Renal Papillary Necrosis (RPN). It was found that 1.3% of IVUs had RPN. There was a higher incidence of RPN amongst males as compared to females. RPN occurred more commonly in the younger age groups.

Adult↗
PubMed1990

The non-covalent interaction of pyrrolo[2, 1-c] [1, 4]benzodiazepine-5, 11-diones with DNA.

A series of 15 pyrrolo[2, 1-c] [1, 4]benzodiazepine-5, 11-diones has been synthesized and evaluated for in vitro DNA binding by thermal denaturation and fluorescence quenching studies with calf thymus (CT) DNA. The results indicate that two compounds of the series, 7 and 8, elevate the melting point of DNA by 2.9 +/- 0.6 and 3.3 +/- 0.8 K, respectively. Similarly, a significant quenching of the fluorescence of the dihydroxy analogue 8 was observed upon interaction with CT-DNA. As controls, the dihydroxy isomer 9 with the reverse stereochemistry at C2 and the non-substituted parent dilactam 12, failed to increase the DNA melting point or exhibit significant quenching upon interaction with DNA. In addition, preliminary experiments with GC- and AT-rich polymers suggest some sequence-dependent properties for dilactams 7 and 8. Overall, these results indicate a highly specific structural requirement for DNA binding. Molecular modelling with d(GTAGATC), d(GCAGATC) and d(GCGTAGC) duplex sequences has provided a model based on hydrogen bonding between the dihydroxy dilactam 8 and DNA, that rationalizes some of the results obtained. It is possible that the observed interactions represent the non-covalent (binding) component of the interaction of covalently-bonding anthramycin-type anti-tumour antibiotics with DNA.

Anthramycin↗
PubMed1986

Antibacterial effect and toxicity of synthesized salicylanilide derivatives.

5 nitro- and chloro-salicylanilide derivatives were synthesized by a simple condensation reaction between phenylsalicylate and the required nitroaniline derivative. The compounds were subjected to direct chlorination in CCl4 without any catalyst and were identified by microanalysis, m. p. and spectral studies. The antibacterial activity was investigated against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus. The prepared derivatives were evaluated for their acute toxicity on Swiss albino mice. The compounds 5,2'-dichloro-4'-nitrosalicylanilide and salicyl-3'-nitroanilide were the most active against the test organisms, but they showed fluctuating toxicity effect at the dose of 500 mg/kg. The structure-activity relationship and the toxicity tests verified the compound salicyl-4'-nitroanilide as a reasonable antibacterial agent against the four test organisms without any sign of toxicity symptoms up to the dose of 1000 mg/kg.

Animals↗
PubMed1986

Analgesic use by leprosy patients.

We questioned 235 subjects with leprosy regarding the consumption of analgesic preparations, and 46 subjects (19.5%) admitted to having consumed more than 2 kg of analgesics; the main reason for consumption was neuritic pain. The commonly consumed analgesics are paracetamol (acetaminophen) and local proprietary compound analgesics containing aspirin, phenacetin, and caffeine. Intravenous urograms were done on 28 of the 46 subjects, but none showed evidence of renal papillary necrosis. The reasons for this lack of renal papillary necrosis are postulated. Excessive ingestion of analgesics may be a contributory factor in the development of interstitial nephritis in patients with leprosy.

Acetaminophen↗
PubMed1984

Analgesic nephropathy associated with paracetamol.

Seven cases of analgesic nephropathy due to excessive ingestion of paracetamol are reported. None of these patients had been taking any other analgesic. All had radiological features of papillary necrosis. With the increasing use of paracetamol as a mild analgesic it is necessary to be aware of the possibility that paracetamol may induce analgesic nephropathy.

Acetaminophen↗