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Biomedical subjects

D Morse

Publications and source records attributed to D Morse.

At least 91 records · Page 5Linked to original sources
PubMed1980

A comparison of the citrate synthases of Escherichia coli and Acinetobacter anitratum.

Citrate synthase has been purified to homogeneity from a strain of the Gram-negative aerobic bacterium Acinetobacter anitratum in a form which retains its sensitivity to the allosteric inhibitor NADH. In subunit size, amino acid composition, and antigenic reactivity the enzyme shows a marked structural resemblance to the citrate synthase of the Gram-negative facultative anaerobe Escherichia coli. Whereas the E. coli enzyme is subject to a strong, hyperbolic inhibition by NADH (Hill's number n = 1.0, Ki = 2 microM), the A. anitratum enzyme shows a weak, sigmoid response (n = 1.6, I0.5 = 140 microM) to this nucleotide. With E. coli, NADH inhibition is competitive with acetyl-CoA, and noncompetitive with oxaloacetate; with A. anitratum, NADH is noncompetitive with both substrates. Acinetobacter anitratum citrate synthase shows hyperbolic saturation with acetyl-CoA (n = 1.8). The finding of Weitzman and Jones (Nature (London) 219, 270 (1968) that NADH inhibition of the enzyme from Acinetobacter spp. is reversible by AMP, while that from E. coli is not, is explained by the much greater affinity of the E. coli enzyme for NADH. Unlike E. coli citrate synthase, the A. anitratum enzyme does not react with the sulfhydryl reagent 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) in the absence of denaturation. With a second sulfhydryl reagent, 4,4'-dithiodipyridine (4,4'-PDS), the A. anitratum enzyme reacts with 1 equiv. of subunit; this modification induces a partial activity loss (attributable to a arise in the Km for acetyl-CoA) and an increase in the sensitivity to NADH. With the E. coli enzyme, 4,4'-PDS causes complete inactivation. Acinetobacter anitratum citrate synthase is much more resistant to urea denaturation than the E. coli enzyme is; the resistance of both enzymes to urea is greatly improved in the presence of 1 M KCl. It is suggested that the amino acid sequences of the subunits of the citrate synthases of these two bacteria are about 90% homologous, and that the 10% differences are in key residues, perhaps largely in the subunit contact regions, which account for the differences in allosteric properties.

Acinetobacter↗
PubMed1980

Successful management of Penicillium endocarditis.

Penicillium endocarditis involving an aortic valvular tissue prosthesis (Ionescu-Shiley) was successfully managed. This is the fourth reported case of Penicillium endocarditis, and the first survivor. A review of the literature shows that this fungus is ubiguitous though rarely pathogenic. The management of this rare type of infection is outlined.

Adult↗
PubMed1976

A unique course in anthropology.

The course in forensic anthropology presented at Florida State University is designed to train criminal investigators in the application of physical anthropological and archaeological techniques to the investigation of buried bodies. Modification of archaeological field techniques by experimentation using artificial graves allows the recovery of fragile and easy to overlook evidence and ensures the recovery of all possible material for analysis by the physical anthropologist. An introduction to physical anthropology enables the criminal investigator to effectively communicate his needs and understand the type of information required for adequate identification of remains by a physical anthropologist.

Anthropology, Physical↗
PubMed1976

Results of mitral valve replacement with the Beall prosthesis in 209 patients.

In this 3 year study of 209 patients who underwent mitral valve replacement with the newer Beall prostheses (Models 104 and 105) the operative mortality rate was 5.2 per cent. None of these deaths was related to the valve. This prosthesis features a larger frustrum area and a "turtle-neck" sewing ring which permits its rapid insertion with a continuous suture technique. Of the 20 (9.5 per cent) late deaths, two were due to thrombosis of the valve. Among the 178 survivors, 17 developed thromboembolic complications; however, 10 of these patients recovered. Late clinical results have been quite satisfactory in over 90 per cent of the survivors. In the 15 patients who underwent hemodynamic studies postoperatively, the cardiac index and pulmonary artery pressure showed significant improvement; however, they still had transvalvular gradients at rest. The improvement in the design of this prosthesis has been an important factor in lowering the operative risk and improving the late results of mitral valve replacement.

Adult↗
PubMed1976

Forensic archaeology.

This presentation attempts to demonstrate the value of the use of improved methods in the excavation of buried bodies involved in a criminal investigation. Care in the removal of the skeleton and proper recording will document the interrelationship of all objects found in and around the grave and can, to a certain extent, recreate the event. Carelessness will result in evidence being irretrievably lost. The crime scene investigator's problem, arachaeologically, includes the nature of the remains, dating the time of burial, and techniques of excavation. Archaeological recovery techniques should be adopted in homicide investigation involving buried bodies.

Age Determination by Skeleton↗
PubMed1975

Preliminary experience with the use of a programmable pacemaker.

One hundred sixty-four patients, in whom new externally programmable pacemakers had been inserted, were studied over a two year period, beginning July, 1972. Following implantation, the rate and current output of this pacemaker could be changed at any time by a non-invasive technique involving electromagnetic pulse trains emitted by an external "programmer". In 89 percent of the patients it was possible to reduce battery output by half, implying greater longevity of the pacer in these cases. In 15 percent of the patients, manipulative control of the pacemaker rate was employed and found beneficial.

Adult↗