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Biomedical subjects

M Sharp

Publications and source records attributed to M Sharp.

32 records · Page 2Linked to original sources
PubMed1980

Cell-mediated immune responses to chlamydial antigens in guinea pigs injected with inactivated chlamydiae.

Cell-mediated immunity (CMI) to chlamydial antigens was readily induced in guinea pigs by a single injection of Betaprone-inactivated chlamydiae in complete Freund adjuvant. The CMI was measured in vivo by delayed hypersensitivity skin tests, and in vitro by inhibition of migration of peritoneal exudate cells and by proliferation of lymph node lymphocytes. There was an overall correlation between in vivo and in vitro responses. Of the in vitro assays, migration inhibition reflected the state of sensitization, as judged by skin tests, more uniformly than lymphocyte stimulation. Extensive inter- and intra-species cross-reactivity was noted between LB-1, a strain of C. trachomatis, and three strains of C. psittaci, 6BC, GPIC, and 562F. Cross-reactivity between LB-1 and 6BC was one-way only, by all three parameters: LB-1 elicited strong cross-reactions in 6BC-immunized animals but not vice versa. Antichlamydial antibodies could not be demonstrated in any of the animals by microimmunofluorescence.

Animals↗
PubMed1980

Manipulating metabolic parameters to improve growth rate and milk secretion.

Several opportunities for improving animal efficiency through manipulation of metabolism are discussed. The first opportunity is through identification and selection of animals achieving close to theoretical efficiencies. Based upon differences between highly efficient and average animals, the estimated opportunity for improvement is 20%. A second opportunity for improvement is through manipulation of apparent maintenance requirements. Several contributors to differences in efficiencies are considered. One is the contribution of differences in relative organ weights to differences in apparent maintenance requirements. A potential benefit in the order of 10 to 20% through selection or manipulation seems possible. Manipulations of ion transport and protein turnover could yield maximum benefits of 30 and 15%, respectively. However, complete elimination of these processes is not feasible. Without ion transport, membrane potentials would not be maintained and, without turnover, many important regulatory processes would be affected. the limit to manipulation of these characteristics is unknown. A third opportunity for improvement of animal efficiency is through improvement of apparent biosynthetic efficiency by manipulation of patterns of nutrient utilization. If we could produce, through hormonal or other types of manipulations, an optimum pattern of nutrient use, decreases in heat increments of production in growing animals in the order of 50% might be achieved.

Adipose Tissue↗
PubMed1979

Human cell-mediated immune responses to chlamydial antigens.

A reproducible method was developed to determine the ability of chlamydial antigens to stimulate lymphocytes from volunteers. In tests repeated 4 to 14 times, the cells from a given volunteer gave a relatively narrow range of responses, but there were great differences in the mean response of different volunteers. In the entire group of 52 volunteers, lymphocyte stimulation was significantly associated with the presence of antibody, but in a given individual results of one test did not aid in predicting the results of the other. A majority of persons with either antichlamydial antibody or elevated lymphocyte stimulation, or both, did not have a history of signs or symptoms within a spectrum of chlamydial diseases. This may reflect the great frequency of asymptomatic infection with these organisms. The lymphocytes of some individuals were stimulated to a significantly greater degree by antigens of one chlamydial species (Chlamydia trachomatis or C. psittaci) than by the other. These and other cell-mediated reactions in human chlamydial infections, and their possible medical significance, are under continued study.

Adult↗
PubMed1978

Auditory function in sickle cell anemia.

Auditory function was assessed in nine black subjects with sickle cell anemia and compared with a control population. No differences were found for measures of hearing acuity and undistorted speech discrimination. However, some suggestion of reduced neural function was observed in terms of acoustic reflex measures and time-compressed speech discrimination. One subject with sickle cell anemia displayed a distinctive auditory profile that we treat separately.

Adolescent↗
PubMed1976

Erythrocyte spectrin. Purification in deoxycholate and preliminary characterization.

Erythrocyte spectrin, isolated by aqueous extraction of erythrocyte ghosts, may be freed from contaminating membrane lipids and small amounts of other proteins by gel chromatography in 5 or 10 mM deoxycholate. The purified protein, in deoxycholate, is a mixture of monomers and dimers, both highly asymmetric molecules. The hydrodynamic properties of the dimer closely resemble those of muscle myosin, and spectrin and myosin also have similar circular dichroism spectra. The proportion of dimer to monomer in the purified protein varies from one preparation to another, an observation for which there is no simple explanation. In the absence of deoxycholate, spectrin associated beyond the dimer stage, possibly by loose end-to-end aggregation involving hydrophobic forces.

Binding Sites↗
PubMed1976

Comparative autosomal linkage in mammals: genetics of esterases in Mus musculus and Rattus norvegicus.

Recombination between Esterase-4 and Esterase-2 in the rat was not observed in 278 backcross offspring. Es-4 is thus included within the "esterase cluster" in Linkage group V. A new map of this region was constructed and the relationship of the four esterase loci was found to be: Es-4-(9.6+/-1.6 cM)-Es-2, Es-4-(1.5+/-0.7cM)-Es-3. Homology of this region with a region of Linkage Group XVIII (Chromosome 8) of the mouse was proposed on the basis of tissue distribution, subcellular localization and response of enzymes to inhibiotrs. Specifically, rat Es-1 was suggested as the homolog of mouse Es-6. An autosomal segment comprising at least 15cM of the rat and mouse genomes appears to have remained relatively intact with respect to genetic content during rodent speciation. In addition, a new polymorphism for mouse esterase was described. The locus was designated Esterase-10 (Es-10) and proposed as the mouse homolog of human Esterase D. Linkage of Es-10 with nucleoside phosphorylase-1-(Np-1) on Chromosome 14 was established.

Alleles↗
PubMedDate not supplied

The Jaipur limb and foot.

In the 12 years which have elapsed since the United Nations declared 1981 to be the Year of the Disabled, the number of amputees world-wide has risen alarmingly, continuing the pattern of the past 40 years, which have seen innumerable conflicts, large and small, with ever-increasing and indiscriminate use of 'improved' antipersonnel mines which have been sown in enormous numbers in rural areas. Even after fighting has ceased--as in Vietnam, which currently has some 200,000 amputees--fresh injuries are caused daily, often to children, by the long-delayed detonation of these weapons. Much of the research and development in prosthetics since World War II has concentrated on producing artificial limbs suitable for an affluent and industrialized society. These, being made from the most modern materials and incorporating the latest technology, are of necessity expensive even for affluent Americans or Europeans and quite out of reach for the 80 per cent of the world's amputees who live in the developing world and for the vast majority of whom these splendid prostheses may be entirely inappropriate. This article describes a foot and leg specifically designed to fit in with the customs and practices of just such people.

Amputation, Traumatic↗