Biomedical subjects
Publications and source records attributed to M R Khan.
The methanol extracts of leaves, root and stem barks of Calophyllum soulattri were partitioned with petrol, dichloromethane, ethyl acetate. The extracts demonstrated a range of antibacterial activity, improved on fractionation. None were found to be active against the moulds.
A broad spectrum of antibacterial activity was exhibited by the methanol extracts of leaves, root and stem barks of Terminalia complanata and Flacourtia zippelii and their subsequent fractions (petrol, dichloromethane, ethyl acetate). Fractionation enhanced the activity particularly in the ethyl acetate fractions of the stem and root barks of T. complanata. No activity was observed against the moulds.
The methanol extracts of leaves, seeds, stem and root barks, stem and root heart-woods of Michelia champaca and the obtained fractions (petrol, dichloromethane, ethyl acetate, butanol) exhibited a broad spectrum of antibacterial activity. Fractionation drastically enhanced the level of activity particularly in all fractions of the stem bark and dichloromethane fraction of the root bark. Some fractions of the leaves, stem and root barks demonstrated antifungal activity against some of the tested moulds. Liriodenine was the active constituent of the root bark, with a broader and, in some cases, better level of activity as compared to the standard.
A case control study was conducted in Dhaka city to measure the energy intake and expenditure among 220 obese children of 4-10 years age group and 220 randomly selected age and sex matched controls. A 24 hour dietary recall was used to assess the energy intake. Data on energy expenditure was obtained by 24 hour physical activity recall. The mean energy intake of obese children (2056 +/- 751 kcal/d) was found to be significantly higher (P<0.001) compared to the non obese (1508 +/- 529 kcal/d). No sex difference was found in both obese and non obese groups. Mean energy expenditure of the obese children (1868 +/- 313 kcal/d vs 1495 +/- 200 kcal/d) was significantly higher than the non-obese (P<0.001). Of the obese, boys expended more energy than the girls (P=0.01). Furthermore, physical activity level (1.40 +/- 0.09 vs 1.35 +/- 0.14) was significantly higher among the non obese than their obese counterpart (P<0.001). However, energy balance was significantly higher among the obese (P<0.001). Dose response of energy balance shows the estimated relative risk of obesity increases with higher level of energy balance (P<0.001). The findings of this study revealed that energy balance as a result of higher energy intake and lower energy expenditure was one of the important risk factors for the development of obesity among the children of Dhaka city. Thus, appropriate interventions like behavioural change regarding food habits and physical activities are recommended.
Failure of coronary angiography (luminography) in prediction of future acute coronary syndromes has cast a shadow of doubt over the value of this old gold-standard technique. The fact that angiographically invisible or nonsignificant lesions cause the majority of acute coronary syndromes has driven scientists to develop new diagnostic methods. In this article, we review the ongoing worldwide research on both invasive techniques (such as intravascular angioscopy and colorimetry, ultrasound, thermography, optical coherence tomography, near infrared spectroscopy, Raman spectroscopy, fluorescence emission spectroscopy, elastography, magnetic resonance imaging and spectroscopy, nuclear immunoscintigraphy, electrical impedance imaging, vascular tissue doppler, and shear stress imaging) and noninvasive techniques (such as MRI, contrast-enhanced MRI with and without immunolabeled agents, electron beam computed tomography, multi-slice spiral / helical computed tomography, and nuclear imaging, including positron emission tomography). Each of these techniques and their potential combination holds promise for characterization of plaques responsible for acute coronary syndromes, namely vulnerable plaque.
The methanol extracts of Castanopsis acuminatissima leaves, stem and root barks were partitioned (petrol, dichloromethane, ethyl acetate). Though all of the crude methanolic extracts and obtained fractions from them, showed a broad spectrum of antibacterial activity, in most cases the activity was decreased on fractionation. None was active against tested moulds.
The methanol extracts of Picrasma javanica, leaves, seeds, stem and root barks were partitioned (petrol, dichloromethane, ethyl acetate, butanol). All obtained extracts and fractions showed a broad spectrum of antibacterial activity, while none was active against the tested moulds.
The methanol extracts of Harpullia ramiflora, leaves, flowers, stem and root barks were partitioned (petrol, dichloromethane, ethyl acetate). In respect to crude extracts, all fractions demonstrated broader spectrum and higher levels of antibacterial activity. The ethyl acetate fraction of the flowers exhibited the highest activity. No activity was shown against the tested moulds.
The ethanol extracts of Omalanthus nervosus leaves, stem and root barks, were partitioned (petrol, dichloromethane, ethyl acetate). In respect to crude extracts, all fractions demonstrated broader spectrum and higher levels of antibacterial activity, ethyl acetate fractions being in all cases the more active. No fraction was active against tested moulds.
The methanol extracts of leaves, root and stem barks of Horsfieldia helwigii and Melia azedarach showed a broad spectrum of antibacterial activity. The activity was increased on fractionation (petrol, dichloromethane, ethyl acetate), particularly in the petrol fraction of the leaves of H. helwigii and dichlorometane fraction of the stem bark of M. azedarach. No activity was shown against tested moulds.
The methanol extracts of leaves, flowers, stem and root barks of Cassia alata showed a broad spectrum of antibacterial activity. The activity was increased on fractionation (petrol, dichloromethane, ethyl acetate), the dichloromethane fraction of the flower extract being the most effective. No activity was shown against tested moulds.
The methanol extracts of Clematis papuasica leaves and stem bark and of Nauclea obversifolia leaves, stem and root barks showed awide spectrum of antibacterial activity which was increased on fractionation (petrol, dichloromethane, ethyl acetate), the ethyl acetate fractions being in all cases the most effective. None of the extractives was active against tested moulds.
The ethanol extracts of Bidens pilosa (whole plant), Bischofia javanica (leaves), Elmerillia papuana (root bark) and Sigesbekia orientalis (whole plant) were partitioned (petrol, dichloromethane, ethyl acetate). The crude ethanolic extracts and all the obtained fractions showed a broad spectrum of antibacterial activity, the ethyl acetate fractions and the petrol fraction of E. papuana being the most effective. No activity was observed against the tested moulds.
The methanol extracts of leaves, stem and root barks of Lithocarpus celebicus showed a broad spectrum of antibacterial activity which was increased on fractionation (petrol, dichloromethane, ethylacetate), particularly in the ethyl acetate fraction of the stem bark and petrol fraction of the root bark. None of the extractives was active against tested moulds.
The methanol extracts of leaves, root and stem barks of Psychotria microlabastra showed a broad spectrum of antibacterial activity, that was increased on fractionation (petrol, dichloromethane, ethyl acetate), particularly in the ethyl acetate fractions. None of the extractives showed activity against the tested moulds.
The methanol extracts of leaves, root and stem barks of Symplocos cochinchinensis and their fractions obtained by partition (petrol, dichloromethane, ethyl acetate) were screened for antimicrobial activity. All the crude extracts and fractions showed a broad spectrum of antibacterial activity, that was enhanced on fractionation. None of them showed activity against the tested moulds.
Two prenylated isoflavones (1 and 2) with a hydroxyisopropyldihydrofuran moiety have been isolated from the wood of Erythrina suberosa var. glabrescence. The structure of compound 1 was in agreement with that of the previously reported senegalensin, isolated from the stem bark of Erythrina senegalensis. The structure of senegalensin was revised from structure 2 to structure 1 by spectroscopic means. Compound 2, the regioisomer of 1, was confirmed as euchrenone b(10) by comparison with the spectral data of the reported euchrenone b(10), isolated from the roots of Euchresta horsfieldii. The structure of 2 was established by 2D NMR spectroscopic analysis and by the X-ray crystallographic analysis of its p-bromobenzoyl derivative (2b).
An epoxy-graphite tube composite electrode bulk modified with 2-mercaptobenzothiazole was investigated for the simultaneous, batch determinations of Bi(III), Hg(II) and Cu(II) by differential-pulse anodic stripping voltammetry after open circuit preconcentration of the three metal ions. Systematic optimization was studied with respect to resolution and sensitivities of the differential-pulse peaks. The resolution between peaks was quantified and employed in a window diagram approach to choose the best conditions. The developed method gave detection limits of 4.2 x 10(-9), 3.6 x 10(-9) and 9.5 x 10(-8) M for Hg(II), Bi(III) and Cu(II), respectively (S/N = 3; 3 min preconcentration). The conditions whereby simultaneous determinations could be performed in the absence of cross-interferences of the analytes were also examined. Additional selected substances in the sample background were also studied for possible interferences. The developed method was applied to the simultaneous, batch determinations of Bi(III), Hg(II) and Cu(II) in a standard sample and a human hair sample.