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Biomedical subjects

M J Davis

Publications and source records attributed to M J Davis.

At least 181 records · Page 10Linked to original sources
PubMed1976

Trichinosis: severe myopathic involvement with recovery.

A case of clinically severe trichinosis following ingestion of commercially prepared pickled pigs' feet is reported. An unusual finding on muscle biopsy was a larval count of 4,046 per gram of muscle, the second highest density of muscle invasion recorded to date. Survival has not been reported previously in patients with greater than 1,000 trichinae per gram of muscle. Complete symptomatic recovery followed combined corticosteroid and thiabendazole administration.

Adult↗
PubMed1976

Mast cell distribution in oral tissues of germ-free vs. conventional beagle dogs.

Light microscopic examination of the mast cell distribution in various oral tissues in germ-free and conventional beagle dogs revealed no differences between the two animals. Mast cells were observed in all tissues examined, with an increasing order of incidence as follows: cervical lymph node, parotid and submandibular glands, marginal gingivae, buccal mucosa and the middle one-third of the tongue. All four types (round, oval, elongated, and pseudopodial) of mast cells cell shapes previously described in the literature were observed. The marginal gingivae associated with the mandibular, second bicuspids was examined by light microscopy and was classified as to degree of inflammatory involvement. In a comparison of germ-free and conventional animals, the distribution of the degree of inflammation proved to be random. Correlation between mast cell densities and the degree of inflammatory infiltration was not statistically significant. However, mast cells tended to decrease as the inflammation became more severe. Electron microscopic examination of mast cells in the buccal mucosa revealed no difference in morphology of cells from germ-free or conventional animals. Cytoplasmic granules were of two basic types, one exhibited an amorphous matrix of uniform density and the other consisted of laminated coils of various sizes and densities.

Animals↗
PubMed1975

International dosimetry: an evaluation of treatment planning in clinical trials.

A tissue-equivalent phantom containing thermoluminescent dosimeters was mailed in succession to Mount Vernon Hospital, Northwood, Middlesex, England, to Groote Schuur Hospital, Capetown, South Africa, and to Winnipeg General Hospital, Winnipeg, Canada, to determine the accuracy and consistency in treatment for carcinoma of the cervix under hyperbaric oxygen conditions. (Protocol of the Medical Research Council's Working Party on Radiotherapy and Hyperbaric Oxygen.) The data were analysed by the Radiological Physics Center, Houston, Texas, and substantiate uniformity at and between the participating institutions.

Canada↗
PubMedDate not supplied

Myogenic and flow-dependent control mechanisms in the coronary microcirculation.

We have recently gained evidence that segmental coronary microvascular diameters, and therefore resistances, are controlled by myogenic and endothelial responses to pressure and flow. Furthermore, intact heart studies are demonstrating that these mechanisms may interact importantly with the metabolic mechanisms primarily governing coronary blood flow. Further studies utilizing measurement of segmental coronary microvascular diameters in isolated microvessels and in the beating heart may elucidate the nature of these interactions. Clinical studies may determine whether reversal of endothelial impairment in the diseased coronary microcirculation contributes to autoregulatory vasodilation, increases resting myocardial perfusion, and increases the threshold for myocardial ischemia during exercise.

Animals↗
PubMedDate not supplied

alpha-adrenergic responses of isolated canine coronary microvessels.

Although alpha-adrenergic activation is known to increase coronary microvascular resistance in vivo, the magnitude of its segmental microvascular consequences is not well understood. Quantification of these effects in vivo is hindered by escape mechanisms that minimize the influences of constrictors, and alterations in flow and pressure, which effect microvascular tone by shear stress-dependent and myogenic mechanisms, respectively. To eliminate these confounding influences, we have studied responses in vitro under conditions with these variables controlled. We evaluated the diameter changes of isolated canine coronary arterioles (110 +/- 12 microns, n = 35) response to alpha-adrenergic activation by norepinephrine (10(-10) to 10(-4) M) in the presence of beta-adrenergic blockade by alprenolol (10(-6) M). In contrast to the situation in vivo, alpha-adrenergic activation did not constrict isolated coronary arterioles, but constricted isolated coronary venules in a dose-dependent manner over a range of 10(-10) to 10(-4) M (-27 +/- 3% maximum diameter change). Coronary arteriolar alpha-adrenergic constriction was not promoted by 1) subthreshold or vasoactive doses of the vasoconstrictors KCl, angiotensin II, U46619, endothelin-1, neuropeptide Y or arginine vasopressin, 2) inhibition of the presynaptic uptake of norepinephrine by imipramine (10(-6) M), 3) inhibition of EDRF synthesis by NG-monomethyl-L-arginine (10(-5) M) or 4) inhibition of prostaglandin synthesis by indomethacin (10(-5) M).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Agonists↗
PubMedDate not supplied

Military assistance in complex emergencies: what have we learned since the Kurdish relief effort?

After the success of relief efforts to the displaced Kurdish population in northern Iraq following the Gulf War, many in the US military and the international relief community saw military forces as critical partners in the response to future complex emergencies (CEs). However, successes in subsequent military involvement in Somalia, Rwanda, the former Yugoslavia, and other CEs proved more elusive and raised many difficult issues. A review of these operations reinforces some basic lessons that must be heeded if the use of military forces in humanitarian relief is to be successful. Each CE is unique, thus, each military mission must be clearly defined and articulated. Armed forces struggle to provide both security and humanitarian relief, particularly when aggressive peace enforcement is required. Significant political and public support is necessary for military involvement and success. Military forces cannot execute humanitarian assistance missions on an ad hoc basis, but must continue to develop doctrine, policy and procedures in this area and adequately train, supply, and equip the units that will be involved in humanitarian relief. Militaries not only must cooperate and coordinate extensively with each other, but also with the governmental and non-governmental humanitarian relief organizations that will be engaged for the long term.

Africa, Central↗