PubMed Health⌕ Search

Biomedical subjects

C V Abraham

Publications and source records attributed to C V Abraham.

13 recordsLinked to original sources
PubMed1977

Isolation and purification of Rh(e) antigen.

Rh(e) antigen from the human erythrocyte membrane has been isolated. The method of preparation was as follows: Red cell membrane was solubilized using ethylenediaminetetraacetic acid followed by sodium chloride. The solubilized components were separated using molecular ultrafilters. The molecular weight class between 20 000 and 30 000 had Rh(e) antigen activity. The Rh(e) antigen was eluted as a single component using isoelectric focusing in a pH gradient of 6 to 8. This Rh(e) antigen inhibits the agglutination of antibody-coated Rh(e) positive cells. This also gives a high titer of antibody when injected into guinea pigs.

Animals↗
PubMed1977

Gas-liquid chromatographic micromethod for the determination of theophylline.

A micromethod for the determination of theophylline using gas-liquid chromatography is described. The volatile ethylated derivative is prepared by the flash-heater derivatization technique. Substances that interfere in the classical determination of theophylline such as caffeine and phenobarbital did not interfere in this procedure. The coefficient of variation was 2.1 percent for 5 microgram/ml and 5.4 percent for 40 microgram/ml. This determination is useful for assessing patient compliance and adjusting dosage schedules.

Chromatography, Gas↗
PubMed1977

Comparison of six procedures for the simultaneous determination of antiepileptic drugs.

A comparison of six gas-chromatographic procedures for the simultaneous analysis of antiepileptic drugs was made. Methylation with 0.2M trimethylanilinium hydroxide was superior to other derivatizing procedures evaluated. The methylated derivatives of phenobarbital, carba-mazepine, primidone, and diphenyl-hydantoin were separated on the chromatogram, and the peaks were sharp and symmetrical. The four drugs gave linear curves to twice their toxic levels.

Anticonvulsants↗
PubMed1976

Simultaneous gas chromatographic analysis for the four commonly used antiepileptic drugs in serum.

We describe a simple, sensitive method for the determination of phenobarbital, diphenylhydantoin, carbamazepine and primidone in serum, by use of gas-liquid chromatography with temperature programming. The methylated derivatives of these anticonvulsants were well resolved, as was 5-(p-methylphenyl)-5-phenylhydantoin, the internal standard. In this procedure we used an ion-exchange resin for separation of the drug from the serum. The proposed procedure requires only 1.0 ml of serum and can be done in less than 1 h. The lower limit of detection for each of the drugs is 0.5 mg/1. Analytical recoveries of drug from serum were excellent and peak height and concentration were linearly related up to twice the toxic concentration for serum.

Anticonvulsants↗
PubMed1976

Isolation and purification of Rh(E) antigen.

The Rh(E) antigen of human red blood cell membranes has been isolated. The method of preparation was as follows: Red cell membranes were solubilized using ethylenediaminetetraacetic acid followed by NaCl. Membrane ultrafilters were used to separtely 75% of the arginine from the polypeptide by chemical treatment of the polypeptide suing methods designed to cleave carboxyl-terminal amino acids. The highly branched structure of the cyanophycin granule polypeptide is similar in form to synthetically produced multichain polyamino acids, and using the nomenclature for describing multichain polyamino acids, it is proposed that the cyanophycin granule polypeptide be called multi-l-arginyl- -polyaspartic acid.

Animals↗
PubMed1976

A modified ortho-toluidine reagent for glucose analysis.

A micromethod for the determination of glucose using a modified ortho-toluidine reagent is described. The proposed method correlates well with the original o-toluidine method. The reaction follows Beer's Law over a wide range of concentrations. The modified reagent contains 75 per cent less glacial acetic acid than the original ortho-toluidine reagent. The color intensity of the Schiff's base is two to three times higher than the original reagent.

Blood Glucose↗
PubMed1976

Simultaneous gas-chromatographic analysis for phenobarbital, diphenylhydantoin, carbamazepine, and primidone in serum.

We describe a simple, sensitive determination of phenobarbital, diphenylhydantoin, carbamazepine, and primidone in serum, by use of gas-liquid chromatography with temperature programming. The methylated derivatives of these anticonvulsants are well resolved, as was 5-(p-methyl-phenyl)-5-phenylhydantoin, the internal standard. The proposed procedure requires only 0.20 ml of serum and can be done in less than 30 min. The lower limit of detection for each of the drugs is 0.5 mg/liter. Analytical recoveries of drug from serum were excellent and peak height and concentration were linearly related up to twice the toxic concentration for serum.

Carbamazepine↗
PubMed1975

Isolation and purification of the Rh(D) blood group receptor component from human erythrocyte membrane.

The Rh(D) antigen of human red blood cell membranes has been isolated as a homogeneous immunologically intact component. The method of preparation was as follows: Red cell membranes were prepared free of hemoglobin and components were solubilized using ethylenediaminetetraacetic acid (EDTA) followed by sodium chloride. Diaflo ultrafilter membranes were used to separate solubilized membrane components into different molecular weight classes. The Rh(D) activity was demonstrated in the molecular weight class between 10 000 and 20 000. This fraction, which had six components by disc gel electrophoresis, was further purified by isoelectric focusing on a pH gradient of 3 to 10, followed by a pH gradient of 5 to 8. The Rh(D) antigen was eluted as a single component, migrated as a discrete band on disc gel electrophoresis, and inhibited the agglutination of anti-Rh(D) antibody. When the Rh(D) antigen was injected into guinea pigs, a high titer of anti-Rh(D) antibody was obtained.

Animals↗