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Biomedical subjects

R Jones

Publications and source records attributed to R Jones.

At least 1,063 records · Page 59Linked to original sources
PubMed1972

Protection of rat bronchial epithelium against tobacco smoke.

Addition to tobacco of phenylmethyloxadiazole (PMO) protects rats against some of the adverse effects of exposure to cigarette smoke. Two groups of 15 rats were exposed to 25 cigarettes a day for 24 days; the group whose cigarette included PMO showed less immediate distress after exposure, a smaller tracheal goblet cell count, less thickening of the tracheal epithelium, and less cells in mitosis than those exposed to ordinary tobacco.

Animals↗
PubMed1972

Effects of denervation and reinnervation on the responses of kitten muscles to acetylcholine and suxamethonium.

1. The development of the high sensitivity of the adult neuromuscular junction to the blocking and depolarizing action of suxamethonium was studied in kittens of different ages.2. It was found that the sensitivity to the depolarizing effects of suxamethonium increases simultaneously with that to the blocking effects of the drug during the 3rd-6th week of life. The increase of sensitivity to the blocking effects of suxamethonium during development can therefore be accounted for by the depolarizing effect of the drug.3. When the nerve is crushed during the first week of the animal's life and then left to regenerate, the development of the high sensitivity of the neuromuscular junction to suxamethonium and acetylcholine is impaired. Thus during development the nerve is essential for the induction of the high sensitivity of the neuromuscular junction to acetylcholine as well as to other depolarizing drugs.4. The blocking and depolarizing effects of suxamethonium on reinnervated muscles of cats at different ages were compared. The depolarizing action of suxamethonium on reinnervated end-plates is always smaller, but its blocking effect is not. In young animals the blocking effect of suxamethonium on reinnervated muscles is smaller, whereas reinnervated muscles of adult animals are extremely sensitive to the blocking effects of the drug.5. 24-36 hr after denervation cat muscles were more sensitive to the blocking effects of suxamethonium but the depolarizing effect of the drug on the end-plate region was smaller. It thus appears that the nerve not only induces but also maintains the high sensitivity of the end-plate region to depolarizing drugs.

Acetylcholine↗
PubMed1972

Evaluation of a microtiter latex agglutination test for histoplasmosis.

Experiments were designed to evaluate a Microtiter latex agglutination (Micro-LA) test, as a serological aid in the diagnosis of histoplasmosis, and to compare this test with the conventional microtiter-complement fixation (CF) test for histoplasmosis. Sera tested were from cases of acute and chronic pulmonary and disseminated histoplasmosis, as well as from individuals not having histoplasmosis. Ninety-seven percent of the cases of acute pulmonary histoplasmosis had positive Micro-LA tests, whereas 91% had positive CF tests. Ninety-six percent of the patients having chronic pulmonary histoplasmosis showed positive Micro-LA tests and 91% had positive CF tests. In contrast, 64% of the cases of disseminated histoplasmosis had positive Micro-LA tests, whereas 82% had positive CF tests. None of these differences was statistically significant. Although there were no significant differences in complement fixing and agglutinating antibody cross-reactivity with Blastomyces antigens, more patients demonstrated CF titers than Micro-LA titers. Sera from patients with acute and chronic histoplasmosis showed higher Micro-LA titers than CF titers, whereas sera from cases of disseminated histoplasmosis showed higher CF titers. Histoplasmin skin testing has less of a boosting effect on agglutinating antibodies than on CF antibodies to histoplasmin. Anticomplementary sera can be used in the Micro-LA test. This test is simple to perform, and results can be obtained in 2 to 4 hr.

Acute Disease↗
PubMed1972

Fish growth.

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Animals↗
PubMed1971

Smoking risks of different tobaccos.

The smoke of English cigarettes (flue-cured tobacco) greatly shortens the life of rats and damages the respiratory system, whereas that of the cigar (air-cured tobacco) is relatively harmless. This bears out two of the principal features in the 1971 Report of the Royal College of Physicians, which draws attention to the large number of premature deaths in cigarette smokers and the comparative safety of smoking cigars.

Animals↗