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Biomedical subjects

J B Hart

Publications and source records attributed to J B Hart.

At least 19 recordsLinked to original sources
PubMed2000

New syntheses of 1D- and 1L-1,2-anhydro-myo-inositol and assessment of their glycosidase inhibitory activities.

The 1D and 1L enantiomers of 1,2-anhydro-myo-inositol (conduritol B epoxide) were synthesised from 1D-pinitol and 1L-quebrachitol, respectively, and their activities were compared in selected glycosidase inhibition assays. The 1D enantiomer was found to be the active isomer, functioning as an irreversible inhibitor of sweet almond beta-D-glucosidase. Neither isomer was active against the alpha-D-glucosidase from Bacillus stearothermophilus or the beta-D-galactosidase from Aspergillus oryzae.

Aspergillus oryzae↗
PubMed2000

1D-3,4-Di-O-(diphenylmethylphosphonio)-1,2,5, 6-tetra-O-methyl-chiro-inositol diiodide.

The title compound, 3,4,5,6-tetramethoxycyclohexane-1, 2-diyldioxybis(methyldiphenylphosphonium) diiodide, C(36)H(44)O(6)P(2)(2+).2I(-), was prepared from a New Zealand natural product, D-chiro-inositol, in order to develop new catalytic metal complexes. The inositol ring retains its usual chair conformation with only minor perturbations caused by the bound diphenylmethylphosphines. Crystal-packing forces are provided by C-H. I cation-anion interactions.

Journal Article↗
PubMed1991

Estimation of maximum tolerated dose for long-term bioassays from acute lethal dose and structure by QSAR.

A quantitative structure-activity relationship (QSAR) model has been developed to estimate maximum tolerated doses (MTD) from structural features of chemicals and the corresponding oral acute lethal doses (LD50) as determined in male rats. The model is based on a set of 269 diverse chemicals which have been tested under the National Cancer Institute/National Toxicology Program (NCI/NTP) protocols. The rat oral LD50 value was the strongest predictor. Additionally, 22 structural descriptors comprising nine substructural MOLSTAC(c) keys, three molecular connectivity indices, and sigma charges on 10 molecular fragments were identified as endpoint predictors. The model explains 76% of the variance and is significant (F = 35.7) at p less than 0.0001 with a standard error of the estimate of 0.40 in the log (1/mol) units used in Hansch-type equations. Cross-validation showed that the difference between the average deleted residual square (0.179) and the model residual square (0.160) was not significant (t = 0.98).

Animals↗
PubMed1978

Temporal patterns of the use of non-prescribed drugs: some behavioral correlates.

Previous studies of the temporal patterns of the use of non-prescribed psychoactive drugs have been primarily limited to users' self-reports. Two behavioral indicators, times of arrest for driving while intoxicated and times of calls to a drug information service, yield temporal patterns very similar to those obtained from users' reports.

Adolescent↗
PubMed1976

The effect that time, touch and environment have upon bacterial contamination of instruments during surgery.

Hemostats were evaluated for frequency of contamination and such contamination was correlated with increasing operating room exposure time. The studies were performed under surgical conditions in operating rooms with and without laminar air flow. The study was also designed to show whether contamination of hemostats were influenced by the scrub nurse's handling. Hemostats were more frequently contaminated in the conventional operating room without laminar air flow (P less than 0.001). Handling by the scrub nurse's gloved hand statistically increased the number of contaminated hemostats (P less than 0.01). Laminar air flow reduced the frequency of contamination statistically (P less than 0.001) to a point where time and touch by a gloved hand of the scrub nurse were not important factors.

Air Movements↗
PubMed1975

The operating room environment as affected by people and the surgical face mask.

The microbiological counts were determined in an operating room suite of 8 rooms and a hallway. The bacterial counts in an empty operating room jumped statistically from 13 CFU/ft2/hr (+/- 31) to 24.8 (+/- 58.8) when the doors were left open (people in the hallways) and 447.3 (+/- 186.7) when 5 people were introduced. The wearing of a surgical face mask had no effect upon the overall operating room environmental contamination and probably work only to redirect the projectile effect of talking and breathing. People are the major source of environmental contamination in the operating room.

Air Microbiology↗