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Biomedical subjects

S M Nelson

Publications and source records attributed to S M Nelson.

11 recordsLinked to original sources
PubMed1994

Effects of selected anti-tumor-promoting chemicals on metabolic cooperation between Chinese hamster V79 cells.

Many tumor-promoting chemicals inhibit gap junctional communication between cells. We investigated the possibility that antipromoting chemicals may act inversely and enhance gap junctional communication. The V79/metabolic cooperation assay is an in vitro test that measures gap junctional communication indirectly by determining the extent of metabolic cooperation between mutant and wild-type V79 Chinese hamster lung fibroblasts in culture. Six in vivo antipromoters (caffeine, 3-isobutyl-1-methylxanthine (IBMX), phenidone, dibromoacetophenone, tosylphenylalanine chloromethyl ketone (TPCK), and acetic acid) were tested in this assay to assess their effects on metabolic cooperation. Caffeine, IBMX, phenidone, and dibromoacetophenone had no effect on metabolic cooperation, while TPCK slightly inhibited metabolic cooperation in one V79 assay. Acetic acid appeared to facilitate metabolic cooperation. In tests where an antipromoter was combined with the established tumor promoter phorbol 12-myristate 13-acetate (PMA), acetic acid, caffeine, and IBMX counteracted PMA-induced inhibition of metabolic cooperation, while phenidone, dibromoacetophenone, and TPCK had little effect. These results indicate that some antipromoters interfere with the ability of a tumor-promoting chemical to inhibit metabolic cooperation and suggest that alteration of gap junctional communication can be a mechanism of antipromoter action.

1-Methyl-3-isobutylxanthine↗
PubMed1990

Influence of carbonated drinking water on tibia strength of domestic cockerels reared in hot environments.

To determine the effects of heat stress and drinking water treatments on physical characteristics of skeletal tissue, tibias of cockerels ranging in age from 4 to 11 weeks were tested for breaking strength. Birds were subjected to either a thermoneutral environment (21 +/- 2 C) or a hot environment (37 +/- 2 C) and supplied with either tap or carbonated drinking water. Breaking strength of tibias was reduced in the hot environment; however, consumption of carbonated drinking water in the hot environment resulted in bone strength comparable with that associated with thermoneutral environment (both types of water). Also, bones from birds of the carbonated water-37 C treatment group had less phase breaks and tended to separate with a single break. Results indicate that hot environment and carbonated drinking water not only affect the previously reported morphologic and chemical characteristics of developing bone, but also their physical attributes.

Animals↗
PubMed1984

Automatic and expectancy-based priming effects in a digit naming task.

In a voice reaction time task, subjects named target digits that were horizontally flanked by noise digits or by a neutral symbol (#). For the control subjects, the noise digits were uncorrelated with the target digit, whereas for three experimental groups, the value of the noise digit predicted the target digit by an arithmetic rule (target = noise, target = noise + 1, target = noise - 1) on 75% of the trials. Patterns of reaction time facilitation and inhibition relative to the control condition among the four subject groups illustrated differing time courses of involuntary and expectancy-based priming. For prediction rules requiring an arithmetic transformation (expect N = 1 and expect N - 1), responses to predicted targets were slowed by response competition at short stimulus-onset asynchrony (SOAs) but greatly facilitated by expectancy at longer SOAs.

Adult↗
PubMed1984

Ear disease and hearing loss among Navajo children--a mass survey.

A team of trained technicians in a specially equipped mobile van conducted a mass screening effort on the Navajo Reservation from 1978 to 1980 to detect and refer individuals with ear disease and hearing loss; 15,890 school children were examined. The prevalence data and correlations of hearing level with ear disease are presented: 4.0% of the children had TM perforations, 2.3% middle ear effusions, 1.9% TM atelectasis, and 0.4% had sensorineural hearing loss. Microtia was found in 1:935, with a cluster on the Western one-fourth of the reservation. Cholesteatoma was rare. The patterns of ear disease are contrasted with other groups.

Acoustic Impedance Tests↗
PubMed1983

Comparative in vitro activity of cefodizime, ceftazidime, aztreonam, and other selected antimicrobial agents against Neisseria gonorrhoeae.

The in vitro activities of three new beta-lactam antimicrobial agents, cefodizime, ceftazidime, and aztreonam (formerly azthreonam), were compared with those of cefotaxime, cefuroxime, cefoxitin, and penicillin against 100 beta-lactamase-negative and 42 beta-lactamase-positive Neisseria gonorrhoeae strains. The three new antimicrobial agents showed excellent activity against N. gonorrhoeae regardless of beta-lactamase production. Cefodizime was as active as cefotaxime and more active than the other test antimicrobial agents. It inhibited all isolates at a concentration of less than or equal to 0.016 micrograms/ml.

Anti-Bacterial Agents↗
PubMed1983

Comparative in vitro activity of Sch 29,482, a new oral penem, against Neisseria gonorrhoeae.

The in vitro activity of Sch 29,482, a new oral beta-lactam antimicrobial agent, was compared with those of norfloxacin, rosoxacin, ampicillin, erythromycin, and tetracycline against 142 Neisseria gonorrhoeae strains. Sch 29,482 was as active as norfloxacin and rosoxacin. Its activity was greater than the other three antimicrobial agents. It inhibited 90% of the isolates, regardless of beta-lactamase activity, at a concentration of less than or equal to 0.06 micrograms/ml.

Administration, Oral↗
PubMed1982

Comparative in vitro activity of norfloxacin (MK-0366) and ten other oral antimicrobial agents against urinary bacterial isolates.

The in vitro activity of a new oral antimicrobial agent, norfloxacin (MK-0366), was compared with those of nalidixic acid, nitrofurantoin, co-trimoxazole, trimethoprim, sulfamethoxazole, cinoxacin, tetracycline, ampicillin, carbenicillin, and cephalexin against 628 urinary bacterial isolates. Norfloxacin was the most active antimicrobial agent tested against the gram-negative bacilli. It was less active than a few of the other antimicrobial agents against enterococci and Staphylococcus aureus.

Anti-Bacterial Agents↗
PubMedDate not supplied

Postauricular Kimura's disease.

Angiolymphoid hyperplasia with eosinophilia (Kimura's disease) is a relatively uncommon subcutaneous lesion, which can be confused with angiosarcoma. A case is presented. The differential diagnosis and therapy are discussed.

Adult↗