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Biomedical subjects

D Adams

Publications and source records attributed to D Adams.

At least 253 records · Page 14Linked to original sources
PubMed1977

Accessory nerve palsy.

After apparently uncomplicated excision of benign lesions in the posterior cervical triangle, two patients had shoulder pain. In one, neck pain and trapezius weakness were not prominent until one month after surgery. Inability to elevate the arm above the horizontal without externally rotating it, and prominent scapular displacement on arm abduction, but not on forward pushing movements, highlighted the trapezius dysfunction and differentiated it from serratus anterior weakness. Spinal accessory nerve lesions should be considered when minor surgical procedures, lymphadenitis, minor trauma, or tumours involved the posterior triangle of the neck.

Accessory Nerve↗
PubMed1977

The effects of left ventricular load and contractility on mitral regurgitant orifice size and flow in the dog.

Acute mitral regurgitation (MR) was produced in 12 dogs by closed chest partial valvulectomy and the relative contributions of MR pressure gradient (MRG), the time for regurgitant flow (VSI), and the MR orifice area (MRA) to mitral regurgitant volume (MRV) assessed. Aortic and left atrial pressures, biplane left ventricular (LV) angiography, forward flow and mitral regurgitant flow (MRF) were measured following MR induction and following augmentation of left ventricular end-diastolic volume (EDV), increased aortic resistance (angiotensin), and in the presence of increased ventricular contractility (calcium or epinephrine). Mitral regurgitation orifice area was determined by calculation and the diameters of the mitral anulus and subvalvular areas measured angiographically. Angiotensin and volume infusion induced a substantial increase in MRF which was largely dependent on an increase in MRA but not MRG, while augmentation of contractility decreased MRF accompanied by a decrease in MRA, relatively independent of MRG. Left ventricular size and shape are major determinants of MRA and resultant MRF in acute mitral regurgitation. These findings may help to explain the effects of such factors as ventricular loading and volume on the clinical course of mitral regurgitation in man.

Animals↗
PubMed1977

The cost and advantages of establishing an age-sex register.

The advantages and disadvantages of different methods of creating an age-sex register are described. The cost of setting up such a register in a NHS practice with 10,000 patients is shown, and it is suggested that financial advantages may cover the costs involved.

Costs and Cost Analysis↗
PubMed1976

Electron spin resonance analysis of irreversible changes induced by calcium perturbation of erythrocyte membranes.

Introduction of calcium during hemolysis of erythrocytes causes irreversible membrane changes, including protein aggregation. These changes have been investigated by incorporation of one protein and three fatty acid spin label probes into washed membranes from erythrocytes hemolyzed with a range of Ca2+ concentrations. Electron spin resonance spectra of the lipid probes were analyzed for changes in the order parameters, isotropic coupling constants and mean angular deviations of the lipid hydrocarbon chains. The results generally indicated an increased freedom of mobility of the probes with increased Ca2+ concentration during hemolysis, but the response of each probe showed a different concentration dependence. The maximal response was obtained with the I(5, 10) probe. Variations in the responses were interpreted to reflect different modes of protein-lipid or protein-probe interactions arising from Ca2+ -induced membrane protein alterations. Spectra from membranes treated with the protein spin label showed an increased ratio of immobilized to mobile label with increased Ca2+ concentrations at hemolysis. This is consistent with the membrane protein aggregation phenomena previously observed. It is suggested that the increased protein-protein interactions formed as a result of calcium treatment permit an increased lipid mobility in the membrane regions monitored by the fatty acid probes.

Calcium↗
PubMed1976

Human alpha-crystallin. I. The isolation and characterization of newly synthesized alpha-crystallin.

Studies of the incorporation of 14C amino acids into human lens proteins demonstrate that an alpha-crystallin fraction takes up more than six times as much radioactivity as any other lens protein. Based on analyses with a calibrated Bio-Gel A-1.5 m column, a molecular weight of 4.9 x 10(5) +/- 5 per cent was obtained for this protein while sedimentation equilibrium analyses indicated a weight average molecular weight, Mw, of 7.5 x 10(5) +/- 4 per cent at 10,000 r.p.m. Gel electrophoresis in sodium dodecyl sulfate revealed two components with molecular weights of 22,000 and 20,000, values similar to those found with calf alpha-crystallin. Alkaline urea gel electrophoresis indicated one major polypeptide with a mobility similar to the B2 chain of calf alpha-crystallin and two major bands with mobilities between those of the calf alpha-crystallin A2 and A1 chains. Amino acid analyses of this newly synthesized alpha-crystallin gave a composition which with a few exceptions is very similar to that of calf alpha-crystallin. All three major polypeptides contained 14C amino acids. However, from the present data, it cannot be determined whether the three polypeptides were independently synthesized or a rapid transformation produced one of the labeled polypeptides in the A region. There appears to be between three and four times as many presumptive A as B polypeptides.

Amino Acids↗
PubMed1976

Keratinization of the oral epithelium.

The morphology of the keratinizing epithelia in the mouth is reviwed in the light of recent knowledge. There appears to be a spectrum of degrees of keratinization rather than distinct types, and a degree of keratinization is reflected in the degree of packing and orientation of tonofilaments. The role of keratohyaline and other granules in the process is discussed and it is suggested that modification of the cell membrane is an important part of keratinization. Although the potential of the various areas in the mucosa is genetically determined and appears early in fetal life, the connective tissue exerts an influence on the extent of keratinization of the surface in a manner which is not understood.

Animals↗