Biomedical subjects

W Hussein

Publications and source records attributed to W Hussein.

5 recordsLinked to original sources

PubMed1995

Conductometric study of interaction between dyes and surface active agents.

The interaction of anionic surface active agents e.g. sodium decyl sulphate (SDS), sodium dodecyl sulphate (SDDS), sodium tetradecyl sulphate (STDS), sodium hexadecyl sulphate (DHDS) and sodium octadecyl sulphate (DODS) with cationic dyes, methylene blue (MB), crystal violet (CV) acridine orange (AO), rhodamine 6G (Rh 6G) and quinacrine dihydrochloride (QD) has been studied in three regions by conductometric titration. In the first region ion pair association occurs and the species (cationic and anionic) exist in equilibrium with homogeneous solution. In the second region complexation occurs by 1:1 with MB, CV and AO and by 2:1 with QD and Rh 6G forming a heterogeneousphase, separation and equilibration containing free ions and ion-pair. In the third region the micelle formation occurs by the excess of anions in the presence of cations as well as ion-pair formation and separated complex ions that give solubilization of the complex to a homogeneous clear solution.

Journal Article↗

PubMed1994

Anodic voltammetry of norgaman at rotating disc platinum and gold electrodes.

Norgaman has been examined by anodic rotating disc electrode voltammetry in buffered media over the range of pH from 0-11.5. The best medium is 0.1 mol 1(-1) sulphuric acid in which the anodic wave is well defined at lower rotation speeds. The compound does not show obedience to the Levich relationship at platinum and gold electrodes. Rapid determination of the compound is not possible due to the adsorption of the oxidation product. Electrode mechanism for the reaction has been elucidated.

Journal Article↗

PubMed1994

Angiotensin-1 converting enzyme (ACE) polymorphism in patients presenting with myocardial infarction or unstable angina.

A deletion/insertion polymorphism in the ACE gene has been reported previously as a potent factor for myocardial infarction. We have tested the frequency of the deletion (D) allele of the ACE gene in 308 consecutive patients admitted to coronary care with chest pain. The gene frequencies were compared with those of 348 controls recruited from the London area. Of 108 Caucasian patients with myocardial infarction, the DD genotype was found more frequently than the combined DI and II genotypes (Chi-square, chi 2 = 5.07, 2P = 0.024). The overall D gene frequency was higher in myocardial infarction patients (125 of 216, 58%) than in controls (347 of 696, 49.9%) (chi 2 = 3.79, 2P = 0.052). In contrast, the DD genotype and D allele frequencies in patients with unstable angina were similar to those found in our normal population. A nonsignificant difference in allele frequency between myocardial infarction and unstable angina patients was observed but the small numbers of subjects studied precludes a more formal comparison. Since unstable angina and myocardial infarction represent a spectrum of coronary thrombosis, it is possible that the DD genotype favours the development of myocardial infarction, perhaps through the presence of higher serum ACE concentrations.

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PubMed1992

Cathodic voltammetry of riboflavin at platinum and gold rotating disc electrodes.

The electroreduction of riboflavin (FMN) has been examined by cathodic rotating disc voltammetry in acidic and basic media at platinum and gold electrodes. It has proved to be diversely reducible best at gold electrode in the alkaline media. Rapid voltametric determination of the substance at gold electrode was effective and gave a mean standard deviation of 1%. Riboflavin at platinum electrode is cathodically active but the voltammograms do not obey the Levich relationship and adsorption destroys the electrode activity. The technique can be conveniently applied to the rapid determination of riboflavin in pure solution and in formulated products.

Journal Article↗

PubMed1992

Cyclic voltammetric adsorption behaviour of riboflavin at platinum electrode.

Cyclic voltammetric technique has been used to determine the electrochemical adsorption behaviour of riboflavin at platinum disc electrode in acidic solution. The electrode loses its activity after the first cyclic curve due to coating of its surface with the adsorbed species. The adsorption strength of riboflavin has been compared with some of the strongly adsorbed materials. This technique is employed to determine the amount of the species adsorbed on the surface of the electrode as the quantity of charge consumed is proportional to the area under the first cycle in the voltammogram.

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