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Biomedical subjects

D L Smith

Publications and source records attributed to D L Smith.

At least 433 records · Page 24Linked to original sources

Spontaneous disruption of the colon associated with pyonephrosis: report of a case.

We report a case of reno-colic fistula with abscess formation, which was treated by staged surgical procedures. One must be wary of automatically implicating the colon as the primary source of the problem when the colon and adjacent organs are involved in an inflammatory process. In cases involving the superior segments of the colon, the kidney or pancreas may be the source of the fistula.

Colonic Diseases↗

Reactions of the carcinogen N-acetoxy-4-acetamidostilbene with nucleosides.

The carcinogen N-acetoxy-4-acetamidostilbene (N-AcO-AAS) yields multiple products in reactions with guanosine, adenosine or cytidine in aqueous acetone. The major product from the reaction with cytidine is a deamination product, 1-(4-acetamidophenyl)-1-(3-uridyl)-2-hydrosy-2-phenylethane. Three minor products were unstable and were characterized only by their UV spectra and pK values. Adenosine yielded two major products, one of them 1-(4-acetamidophenyl)-1-(N6-adenoxyl)-2-hydroxy-2-phenylethane, and the second 3-(beta-D-ribosyl)-7-phenyl-8-(4-acetamidophenyl)-7,8 dihydroimidazo [2,1-i] purine. The major adduct with guanosine is 1-(4-acetamidophenyl)-1-(1-guanosyl)-2-hydroxy-2-phenylethane. One minor adduct also appears to be a guanosine-N-1 derivative, while two other minor adducts yield 1-(4-acetamidophenyl)-2-phenyl-1, 2-ethanediol on acid hydrolysis, and thus appear to be O6-derivatives. None of the guanine adducts isolated had the properties of N-7, C-8 or N2 adducts. In this respect, N-Aco-AAS appears to behave more like a classical alkylating agent than like previously studied N-acetoxy-N-arylacetamides, although the target organs of 4-acetamidostilbene are the same as those of other N-arylacetamides.

Adenosine↗

The efficiency of respiratory filters in a coke oven atmosphere.

Several types of commercially available respiratory filter/sorbent combinations were tested in a coke oven environment. The percent penetration of benzene soluble particulate and benzo(a)pyrene through these filters was determined and was generally found to be less than ten percent. Degradation of filtering efficiency was noted with some types of filters. The use of a sorbent cartridge in conjunction with a covering filter did not significantly change penetration of the contaminants which were measured.

Analysis of Variance↗

High-resolution gas chromatographic profiles of volatile organic compounds produced by microorganisms at refrigerated temperatures.

Three different strains of bacteria isolated from spoiled, uncooked chicken were grown in pure culture on Trypticase soy agar supplemented with yeast extract. The volatile organic compounds produced by each culture were concentrated on a porous polymer precolumn and analyzed by high-resolution gas chromatographic mass spectrometry. Twenty different compounds were identified. Both qualitative and quantitative differences in the chromatographic profiles from each culture were found.

Animals↗

Assessment of the impact of medical device legislation on the dental trade industry.

FDA authority over medical devices is a fact of life, certain to have an effect on the dental trade industry. Trends toward acquisitions and mergers of companies within the dental trade industry and the employment of additional personnel, in response to the regulations, have already become apparent. While some improvement in the quality of dental products can be anticipated, it is also expected that the regulations will result in fewer sources of dental products, higher costs for products fewer new products, and a reluctance to accept goods for return or repair. Whether the net impact of the Medical Device Amendments upon the industry will be positive or negative, remains to be seen.

Dental Equipment↗

Mental effects of mercury poisoning.

Three dentists suffered symptoms of mercury poisoning from the use of this substance in the production of amalgam for dental fillings. The problem of mercury absorption in dental offices has been well documented in the dental literature. The three cases are presented.

Adult↗

Patient recall of medication information.

One hundred and nine patients were randomly assigned to the study groups. All questions were administered by the same pharmacist as outlined on a standard questionnaire. Tetracycline was selected as the study drug. All patients were given a pre-test and post-test in order to assess the degree of learning which took place during their pharmacy visit. Patient data were tabulated and analyzed statistically. The mean level of recall prior to pharmacist intervention was 26.6 percent. The highest level of recall obtained was 89.2 percent which occurred in patients who received both verbal and written medication instructions from the pharmacist. Through the use of verbal and/or written instructions, the pharmacist was able to reinforce the medication instructions of the physician and had a significant impact on the level of patient knowledge.

Attitude to Health↗

A rapid micro method for the simultaneous determination of phagocytic-microbiocidal activity of human peripheral blood leukocytes in vitro.

A new, simple technique for simultaneously studying phagocytic and microbiocidal functions, using viable eukaryotic and prokaryotic microbes, is described. Fresh human venous blood from volunteers was placed on a coverglass and incubated to allow leukocyte adhesion to the coverglass. After clot removal, viable microbes in suspension were added and the coverglass preparation was incubated to allow phagocytosis. The excess microbes (E. coli, S. aureus, L. monocytogenes, and C. albicans each have been used) were then rinsed off, and the vital fluorochrome, acridine orange (AO), was used for staining. A wet mount was prepared and examined by reflected fluorescence with an ultraviolet microscope. Intact (viable) polymorphonuclear (PMN) leukocyte nuclei and microbes appeared green (orthochromatic). Granules in the PMN cytoplasm were yellow or reddish. Nonviable PMN nuclei appeared yellowish or reddish and the nonviable microbes appeared bright red (metachromatic). Thus, phagocytized microbes may be counted and identified as viable or non-viable.

Acridines↗

Combined effects of tobacco and caffeine on the components of choice reaction-time heart rate, and hand steadiness.

Eight male smokers were tested under 6 conditions comprising the combinations of 200 mg. caffeine or no caffeine, with no cigarette, one 0.3-mg. nicotine cigarette or one 1.3-mg. nicotine cigarette, for decision time and motor time scores on a choice reaction-time task. Heart rate was monitored from a pretest period throughout the session, and hand steadiness measured on repeated occasions. Decision-time scores were significantly decreased by both caffeine and nicotine, but no interaction was found. The high-nicotine cigarette had the greatest effect. Motor time scores were improved by caffeine only. Both caffeine alone and nicotine alone accelerated the heart rate but in combination appeared to have antagonistic effects. Hand steadiness was significantly impaired by both drugs but with no interaction.

Adult↗

Myocardial protection with cold, ischemic, potassium-induced cardioplegia.

A total of 204 patients, ages 3 months to 84 years, underwent open-heart surgery with the aid of cardiopulmonary bypass with moderate hypothermia. For protection of the myocardium, cardioplegia was induced by washing out the coronary arteries with an iced, buffered, isoosmolar, potassium-based infusate. After aortic cross-clamping, the aortic root or individual coronary arteries were perfused with 500 to 2,000 c.c. of an aqueous solution (at zero to 4 degrees C.) containing 20 mEq. of potassium. Periods of ischemic arrest as long as 208 minutes have been well tolerated, with only two of the eleven hospital deaths considered heart related. Defibrillation occurred spontaneously in 41 per cent and after one shock in 47 per cent of patient, without apparent correlation between duration of ischemia and restoration of effective rhythm.

Cardiac Surgical Procedures↗