Biomedical subjects

Ghulam Mustafa

Publications and source records attributed to Ghulam Mustafa.

6 recordsLinked to original sources

PubMed2005

Desorption of cadmium from goethite: effects of pH, temperature and aging.

Cadmium is perhaps environmentally the most significant heavy metal in soils. Bioavailability, remobilization and fate of Cd entering in soils are usually controlled by adsorption-desorption reactions on Fe oxides. Adsorption of Cd on soil colloids including Fe oxides has been extensively studied but Cd desorption from such soil minerals has received relatively little attention. Some factors that affect Cd adsorption on goethite include pH, temperature, aging, type of index cations, Cd concentrations, solution ionic strength and presence of organic and inorganic ions. This research was conducted to study the influence of pH, temperature and aging on Cd desorption from goethite. Batch experiments were conducted to evaluate Cd desorption from goethite with 0.01 M Ca(NO3)2. In these experiments Cd desorption was observed at 20, 40 and 70 degrees C in combination with aging for 16 h, 30, 90 and 180 d from goethite that adsorbed Cd from solutions containing initial Cd concentrations of 20, 80 and 180 microM. Following the adsorption step Cd desorption was measured by 15 successive desorptions after aging at various temperatures. At the lowest amount of initially adsorbed Cd and equilibrium pH 5.5, cumulative Cd desorption decreased from 71% to 17% with aging from 16 h to 180 d and the corresponding decrease at equilibrium pH 6.0 was from 32% to 3%. There was a substantial decrease in Cd desorption with increasing equilibration temperature. For example, in goethite with the lowest amount of initial adsorption at equilibrium pH 5.5, cumulative Cd desorption decreased from 71% to 31% with increase in temperature from 20 to 70 degrees C, even after 16 h. Dissolution of Cd adsorbed goethite in 1M HCl, after 15 successive desorptions with 0.01 M Ca(NO3)2, indicated that approximately 60% of the Cd was surface adsorbed. Overall, dissolution kinetics data revealed that 23% to 88% Cd could not be desorbed, which could possibly be diffused into the cracks and got entrapped in goethite crystals. At elevated temperature increased equilibrium solution pH favoured the formation of CaCO3 and CdCO3 which reasonably decreased Cd desorption. Cadmium speciation showed the formation of calcite and otavite minerals at 40 and 70 degrees C due to increase in pH (>9.5) during aging. X-ray diffraction analysis (XRD) of these samples also revealed the formation of CaCO3 at elevated temperatures with aging. While mechanisms such as Cd diffusion and/or entrapment into fissures and cracks in goethite structure with increase in temperature and aging are possible.

Adsorption↗

PubMed2004

Cadmium adsorption and desorption behaviour on goethite at low equilibrium concentrations: effects of pH and index cations.

The transport and bioavailability of cadmium is governed mainly by its adsorption-desorption reactions with minerals such as goethite--a common iron oxide mineral in variable charged and highly weathered tropical soils. Soil factors such as pH, temperature, solution Cd concentration, ionic strength and ageing affect Cd adsorption on goethite. The desorption behaviour of Cd from goethite at low concentrations is not fully understood. This study investigates the adsorption-desorption of Cd at low Cd concentrations (Cd adsorbed on goethite from 20 to 300 microM Cd solutions) in Na and Ca nitrate solutions of 0.03 M nominal ionic strengths. Synthetic goethite prepared by ageing a ferric hydroxide gel at high pH and room temperature was used for Cd adsorption and desorption studies. For desorption experiment 10 successive desorptions were made for the whole range of initial Cd concentrations (20-300 microM) in the presence of 0.01 M Ca(NO3)2 or 0.03 M NaNO3 solutions. Cadmium adsorption was found to be higher in Na+ than Ca2+ probably due to the competition of Ca2+ ions with Cd2+ ions for adsorption sites on the surfaces of goethite. The effect of index cation on Cd adsorption diminished with increase in pH from 5.0 to 6.0. Cadmium desorption decreased with increase in pH from 5.0 to 6.0 in both Na and Ca systems. After 10 successive desorptions with 0.03 M NaNO3 at the lowest initially adsorbed Cd approximately 45%, 20% and 7% of the adsorbed Cd was desorbed at pH 5.0, 5.5 and 6.0, respectively. The corresponding desorptions in the presence of 0.01 M Ca(NO3)2 were 49%, 22% and 8%, respectively. The Freundlich parameter, k, based on each progressive step of desorption at different adsorbed concentration increased with increasing desorption step, which may indicates that a fraction of Cd was resistant to desorption. Low Cd desorbability from goethite may be due to its specific adsorption and/or possibly as a result of Cd entrapment in the cracks or defects in goethite structure.

Adsorption↗

PubMed2004

Comparative lipid profile studies in cardiac and diabetic conditions.

Lipid profile in cardiac patients (myocardial infarction, angina pectoris, coronary heart disease, ischaemic heart disease), diabetic patients and normal humans was investigated. Total serum cholesterol, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides, blood glucose, calcium, potassium and sodium were determined, employing established methods and procedures. Higher level of total cholesterol, LDL-C and triglyceride were found in both cardiac and diabetic patients, however, cardiac patients had much lower level of HDL-C as compared to normal humans. Age wise comparison revealed that level of total cholesterol; triglyceride and LDL-C were elevating while the level of HDL-C were decreasing with the age in cardiac and diabetic patients. Sex wise comparison showed that females had higher HDL-C level than males and therefore had fewer incidences of heart diseases. The level of Ca++, K+ and Na+ were similar in all age groups and sexes. No significant elevation in the level of these electrolytes was discovered.

Journal Article↗

PubMed2003

Hypertriglyceridemia in pediatrics.

Primary hypertriglyceridemias are very rare in pediatric age group. A case of 12 years old boy with hypertriglyceridemia is presented. He was being treated as a case of thalassemia major since 2 years of age and was picked up incidentally when his serum turned milky on standing. Since hypertriglyceridemia is a known risk factor for the acute pancreatitis so an early detection is helpful in adoption of a healthy life style.

Child↗

PubMed2002

Alpha-glucosidase inhibitory constituents from Cuscuta reflexa.

Two new compounds, 7'-(3',4'-dihydroxyphenyl)-N-[(4-methoxyphenyl)ethyl]propenamide (4), and 7'-(4'-hydroxy,3'-methoxyphenyl)-N-[(4-butylphenyl)ethyl]propenamide (5) have been isolated from Cuscuta reflexa along with five known compounds, 6,7-dimethoxy-2H-1-benzopyran-2-one (1), 3-(3,4-dihydroxyphenyl)-2-propen-1-ethanoate (2), 6,7,8-trimethoxy-2H-1-benzopyran-2-one (3), 3-(4-O-beta-D-glucopyranoside-3,5-dimethoxyphenyl)-2-propen-1-ol (6), 2-(3-hydroxy-4-methoxyphenyl)-3,5-dihydroxy-7-O-beta-D-glucopyranoside-4H-1-benzopyrane-4-one (7), reported for the first time from this species. Structures of these compounds were determined by spectral analysis. These compounds showed strong inhibitory activity against alpha-glucosidase.

Amides↗

PubMedDate not supplied

Frequency of glucose 6 phosphate dehydrogenase deficiency and related hemolytic anemia in Riyadh, Saudi Arabia.

BACKGROUND: Glucose 6 Phosphate dehydrogenase deficiency is present in over 400 million people world wide. It is more common iin tropical and subtropical countries and is one of the important causes of hemolytic anemia and neonatal jaundice. We studied the frequency of glucose-6-phosphate dehydrogenase deficiency and associated complications in Central Region (Riyadh) of Saudi Arabia. METHODS: A total of 1740 subjects referred by Ministry of Interior and different hospitals in Riyadh were investigated for glucose-6-phosphate dehydrogenase deficiency. Glucose 6 phosphate dehydrogenase activity was determined by a screening test described by Beutler. RESULTS: Out of these, 106 (6.09%) subjects were deficient. The subjects were divided into marriage and hospital groups. In marriage group deficiency was 4.1% while in hospital group it was 13.3%. In 54 glucose-6-phosphate dehydrogenase deficient patients red blood cell count and haemoglobin levels were determined to see the degree of anaemia. Sixty one percent (61%) had anaemia. In hospital patients 8% patients had severe anaemia while in marriage group no patients had severe anaemia. However mild anaemia was seen in 25% subjects in marriage group. CONCLUSIONS: In conclusion the study indicates that glucose-6-phosphate dehydrogenase deficiency is common in the central region of Saudi Arabia and a lot of patients present with haemolytic episodes. The haemolytic crisis however is not related to the intake of fava beans. The type of variant causing anaemia and suggestions for prevention in marriage group are outlined.

Adolescent↗