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Biomedical subjects

H T Smith

Publications and source records attributed to H T Smith.

At least 55 records · Page 3Linked to original sources
PubMed1978

Trace determination of chlorpheniramine in plasma by GLC using a nitrogen-phosphorous (N-P) detector.

A fast, sensitive and specific method for the determination of chlorpheniramine in plasma is described. The drug was extracted with diethylether, back extracted in hydrochloric acid and reextracted in diethylether. The extract was evaporated to dryness and reconstituted in isopropyl alcohol. The isopropyl alcoholic solution was gas chromatographed without any derivatization and the detection was carried out using a nitrogen sensitive detector. The mean recovery of chlorpheniramine was found to be 96% and a drug level as low as 0.5 ng/ml can be accurately measured.

Animals↗
PubMed1978

Effect of specific lysine modification on the reduction of cytochrome c by succinate-cytochrome c reductase.

The reduction of cytochrome c by succinate-cytochrome c reductase was studied at very low cytochrome c concentrations where the reaction between cytochrome c1 and cytochrome c was rate limiting. The rate constant for the reaction was found to be independent of ionic strength up to 0.1 M chloride, and to decrease rapidly at higher ionic strength, suggesting that the interaction between cytochrome c1 and cytochrome c was primarily electrostatic. The reaction rates of cytochrome c derivatives modified at single lysine residues to form trifluoroacetylated or trifluoromethylphenylcarbamylated cytochromes c were studied to determine the role of individual lysines in the reaction. None of the modifications affected the reaction at low ionic strength, but at higher ionic strength the reaction rate was substantially decreased by modification of those lysines surrounding the heme crevice, lysine-8, -13, -27, -72, and -79. Modification of lysine-22, -25, -55, -99, and -100 had no effect on the rate. These results indicate that the binding site on cytochrome c for cytochrome c1 overlaps considerably with that for cytochrome oxidase, suggesting that cytochrome c might undergo some type of rotational diffusion during the electron-transport process.

Animals↗
PubMed1977

Use of specific lysine modifications to locate the reaction site of cytochrome c with cytochrome oxidase.

The reaction of cytochrome c with trifluoromethylphenyl isocyanate was carried out under conditions which led to the modification of a small number of the 19 lysines. Extensive ion-exchange chromatography was used to separate and purify six different derivatives, each modified at a single lysine residue, lysines 8, 13, 27, 72, 79, and 100, respectively. The only modifications which affected the activity of cytochrome c with cytochrome oxidase (EC 1.9.3.1) were those of lysines immediately surrounding the heme crevice, lysines 13, 27, 72, and 79, and also lysine 8 at the top of the heme crevice. In each case, the modified cytochrome c had the same maximum velocity as that of native cytochrome c, but an increased Michaelis constant for high affinity phase of the reaction. This supports the hypothesis that the cytochrome oxidase reaction site is located in the heme crevice region, and the highly conserved lysine residues surrounding the heme crevice are important in the binding.

Binding Sites↗
PubMed1977

Effective patient scheduling.

Patient appointments and scheduling of patients and physicians are the first step in any health-care delivery system. This paper deals with the conventional method usually found in preprinted appointment books, and the "wave" method. A method of testing this system is any practice environment is described, together with the comparative benefits of the wave method over the conventional method of scheduling. This paper also exemplifies one kind of research that can be accomplished in the private, ambulatory sector of medicine.

Appointments and Schedules↗
PubMed1976

An enzyme kinetics and 19F nuclear magnetic resonance study of selectively trifluoroacetylated cytochrome c derivatives.

The reaction of cytochrome c with ethyl thioltrifluoroacetate was carried out under conditions which led to the selective trifluoroacetylation of a small number of the 19 lysines. The mixture of derivatives was separated by ion-exchange chromatography and four different derivatives with well-resolved 19F nuclear magnetic resonance (NMR) spectra were obtained. Peptide mapping techniques indicated that one of these derivatives contained a single trifluoroacetyl group at lysine 22, and another derivative was singly labeled at lysine 25. The trifluoroacetylated lysine 22 derivative was fully active toward both succinate-cytochrome c reductase (EC 1.3.99.1) and cytochrome oxidase (EC 1.9.3.1) white the trifluoroacetylated lysine 25 derivative was fully active toward the reductase, but had a threefold greater Michaelis constant in the cytochrome oxidase reactin. This supports the hypothesis that the cytochrome oxidase binding site is located in the heme cervice region, and that Lys-25 is important in the binding. 19FNMR spectra of the cytochrome c derivatives bound to phospholipid vesicles were obtained. The reasonably narrow line widths (35-65 Hz) and good sensitivity of the trifluoroacetyl resonances indicated that they might be useful probes for the interaction of cytochrome c with intact mitochondria.

Arginine↗
PubMed1975

Combining medical information with a business data system.

The School of Primary Medical Care at the University of Alabama in Huntsville is presently developing and implementing a computerized clinical data system that incorporates data from the Family Practice Center and the community hospital. The system can be used for the problem-oriented medical record, business and billing, the teaching program, community medicine research, and the evaluation of medical students and family practice residents. This paper discusses plans for the total system and the present degree of implementation.

Alabama↗