Biomedical subjects
B Underwood
Publications and source records attributed to B Underwood.
Ethnicity and poverty are not deterrents to high childhood immunisation rates.
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A survey of alcohol and drug use among UK based dental undergraduates.
OBJECTIVE: This study was designed to investigate the prevalence of alcohol and drug use. DESIGN: Anonymous self-report questionnaire. SETTING: A UK dental school in May 1998. SUBJECTS AND METHODS: 1st-5th year dental undergraduates (n = 264) were questioned on their use of alcohol and tobacco, cannabis and other illicit drugs whilst at dental school, and before entry. RESULTS: Eighty two per cent of male and 90% of female undergraduates reported drinking alcohol. Of those drinking, 63% of males and 42% of females drank in excess of sensible weekly limits (14 units for females, 21 units for males), with 56% of males and 58.5% of females 'binge drinking'. Regular tobacco smoking (10 or more cigarettes a day) was found to have a statistically significant association with year of study, 4th-5th year undergraduates being eight times more likely to regularly smoke than their junior colleagues. Fifty five per cent of undergraduates reported cannabis use at least once or twice since starting dental school, with 8% of males and 6% of females reporting current regular use at least once a week. CONCLUSION: Dental undergraduates are drinking above sensible weekly limits of alcohol, binge drinking and indulging in illicit drug use. Dental Schools should designate a teacher responsible for education of undergraduates regarding alcohol and substance abuse.
Effects of antiprogestins on the rate of proliferation of breast cancer cells.
We have examined the influence of progestins (progesterone, R5020) and antiprogestins (RU486, ZK98299, Org 31710 and Org 31806) on the rate of proliferation of wild type T47D cells cultured in whole fetal bovine serum (FBS) or in single charcoal stripped fetal bovine serum (SSFBS). All of the progesterone antagonists RU486, ZK98299 and two novel antiprogestins Org 31710 and Org 31806 inhibited cell proliferation when cells were cultured in FBS. In contrast, all of the antiprogestins with the exception of ZK98299 enhanced cell growth when cells were cultured in SSFBS. This stimulatory effect of RU486 was observed only at a high concentration of the ligand (1 microM). The effect of R5020, however, was concentration independent. The number of cells in the presence of RU486 was approximately 600% followed by R5020 approximately 400% above control values after a 28 day culturing period. In contrast, when the cells were grown in the presence of medium containing non-stripped whole serum, RU486 inhibited the extent of cell proliferation by 45%. Estradiol (E2) stimulated the rate of proliferation in cells cultured in SSFBS. Similar to when cells were cultured in whole serum, the antiprogestins inhibited cell growth in E2-supplemented SSFBS. Detection of the growth enhancement effects of progesterone receptor (PR) ligands such as RU486 and R5020 on the cells grown in charcoal-stripped medium appear to require the removal of E2 by charcoal stripping of the serum.
Characterization of ligand binding, DNA binding and phosphorylation of progesterone receptor by two novel progesterone receptor antagonist ligands.
In order to gain a better understanding of the distinctive mechanisms of the various types of antiprogestins, we have characterized in vitro ligand binding, specific DNA binding and phosphorylation of progesterone receptor (PR) from T47D cells after treatment of cells with progestins (progesterone, R5020) and antiprogestins (RU486, ZK98299, Org 31806 and Org 31710). Treatment of the cells with R5020 or PR antagonists, with the exception of ZK98299, resulted in a quantitative upshift of PR-A and PR-B indicative of ligand/DNA-induced phosphorylation of PR. Treatment of cells with RU486, Org 31710 or Org 31806, but not R5020 or ZK98299 resulted in detectable PR-progesterone response element complexes (PR-PREc) as assessed by gel mobility shift assay. Although treatment of cells with ZK98299, a type I PR antagonist, did not induce phosphorylation, the antiprogestins, Org 31806 and Org 31710, in a manner identical to RU486, did. Our data suggest that Org 31806 and Org 31710 affect properties of PR from T47D cells that are similar to RU486.
Biochemical factors in the lens opacities. Case-control study. The Lens Opacities Case-Control Study Group.
OBJECTIVE: To evaluate associations with biochemical indicators of nutritional and other risk factors in the Lens Opacities Case-Control Study. DESIGN: Case-control study. SETTING AND PARTICIPANTS: The Lens Opacities Case-Control Study determined risk factors for cortical, nuclear, and posterior subcapsular opacities among 1380 participants aged 40 to 79 years. DATA COLLECTION: Vitamin E, selenium, and biochemistry profile determinations were performed on all patients; red blood cell enzymes and amino acids were measured in systematic samples of about 25% of the Lens Opacities Case-Control Study population. OUTCOME: Laboratory test values in cases and controls were compared and expressed as odds ratios and 95% confidence intervals. RESULTS: In polychotomous logistic regression analyses controlling for age and sex, the risk of opacities was reduced to less than one half in persons with higher levels of vitamin E (odds ratio, 0.44 for nuclear opacities), albumin-globulin ratio (odds ratio, 0.41 for mixed opacities), or iron (odds ratio, 0.43 for cortical opacities); higher uric acid levels increased risk (odds ratio, 1.74 for mixed opacities). Persons with opacities were twice as likely to have high glutathione reductase activity (with flavin adenine dinucleotide), which suggests low riboflavin status (odds ratio, 2.13). Most odds ratios for amino acids were under unity and were significantly decreased for glycine (0.36) and aspartic acid (0.31). CONCLUSIONS: Lens opacities were associated with lower levels of riboflavin, vitamin E, iron, and protein nutritional status. Higher levels of uric acid increased risk of mixed opacities. The findings for riboflavin, vitamin E, iron, and uric acid are compatible with the dietary intake and medical history results of the Lens Opacities Case-Control Study.
Lack of effect of tacrine administration on the anticoagulant activity of warfarin.
The effect of tacrine administration on prothrombin time was studied in 13 patients receiving prolonged warfarin therapy. After a 3-week baseline period and 5 days of placebo administration, patients received 20 mg tacrine four times daily for 5 days. Prothrombin times were determined during baseline, daily before the morning doses of placebo and tacrine, and 14 days after the last tacrine dose (closeout). Mean (+/- SD) prothrombin times were 16.2 +/- 2.8 seconds at baseline, 15.1 +/- 2.6 seconds during the placebo phase, 15.8 +/- 3.6 seconds during the tacrine phase, and 15.3 +/- 3.6 seconds at closeout, indicating that tacrine has no effect on the anticoagulant activity of warfarin. Alteration of warfarin dosage should not be required in patients receiving concurrent tacrine therapy.
Notable increase in content of cytochrome P-450 enzymes in Saccharomyces cerevisiae in repetitive alternating culturing.
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Cell growth associated regulation of c-myc and c-fos in normal human T cells.
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Absorption of vitamin A by children with diarrhoea during treatment with oral rehydration salt solution.
The results of a study of absorption by children of vitamin A indicate that absorption is lower in children with acute diarrhoea compared with normal children. The glucose or electrolytes present in solutions of oral rehydration salts had no effect on the absorption. Despite malabsorption, 70% of the administered dose of 100 000 IU of vitamin A in 500 ml of fluid was absorbed and retained.
The role of ionic signals in early gene induction during T cell activation.
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Comparison of messenger RNAs induced in cells infected with each member of the morbillivirus group.
Virus-specific mRNAs radiolabelled with [32P]orthophosphate in the presence of actinomycin D were extracted from the cytoplasm of Vero cells infected with each of the known morbilliviruses: measles virus, canine distemper virus, rinderpest virus, and peste des petits ruminants virus. When analysed on denaturing agarose-formaldehyde gels the major RNA species from all viruses in the group were identical, except for canine distemper virus where one of the virus-specific mRNAs (mRNA 5), which probably codes for the virus haemagglutinin (S.E.H. Russell, D. K. Clarke, E. M. Hoey, B. K. Rima, S. J. Martin, J. Gen. Virol. 66, 433-441 (1985], was significantly smaller than the corresponding mRNA induced by the other viruses. Plasmid DNA containing a virus-specific insert, representing greater than 98% of the gene derived from the P-protein mRNA of canine distemper virus, showed significant cross-hybridisation with all the other members of the morbillivirus group.
Comparative metabolism of the cis and trans isomers of N-nitroso-2,6-dimethylmorpholine in rats, hamsters and guinea pigs.
The in vivo metabolism of the cis and trans isomers of N-[3,5-3H]nitroso-2,6-dimethylmorpholine (NDMM) was studied in female Fischer rats, Syrian golden hamsters and guinea pigs by analysis of urinary metabolites using high pressure liquid chromatography (HPLC). Animals were treated by gavage with 12 mg/kg body wt. of NDMM, composed of both isomers and 12 microCi/kg body wt. of either of the separated radioactive isomers (cis or trans). Control animals received 12 mg, 12 microCi/kg body wt. NDMM with both isomers labeled in their natural proportion. There was a substantial increase in the excretion of a particular metabolite, 2-(2-hydroxyl-methyl)ethoxy propanoic acid, in the urine of rats, hamsters and guinea pigs 24 h after received the trans isomer (24, 22 and 13% of the total dose excreted, respectively). A minor metabolite was determined to be 2,6-dimethylmorpholine-3-one, another product of alpha-oxidation. The metabolite 1-amino-2-hydroxypropanol was identified, indicating that NDMM was metabolized by both alpha- and beta-oxidation. In all three species, animals administered the cis isomer excreted larger amounts of N-nitroso(2-hydroxypropyl)(2-oxopropyl)amine (HPOP) and N-nitroso-bis(2-hydroxypropyl)amine (BHP) products of beta oxidation, than those treated with the trans isomer. Hamsters and guinea pigs treated with the more carcinogenic cis isomer in these species, also excreted twice as much of two other metabolites than was found in the urine of animals given the trans isomer. The trans isomer of NDMM appeared to be preferentially metabolized by alpha-oxidation and from earlier studies this metabolic pathway seemed to be important in carcinogenesis by NDMM in the rat. The cis isomer might be in a conformation more favorable for beta-oxidation and this pathway may be of primary importance in carcinogenesis by NDMM in hamsters and guinea pigs.
Importance of the early diagnosis of vitamin A deficiency at the epidemiological level.
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Comparative metabolism of 2,6-dimethylnitrosomorpholine in rats, hamsters, and guinea pigs.
The metabolism of N-[3,5-3H]nitroso-2,6-dimethylmorpholine (NDMM) was studied in female Sprague-Dawley rats. Syrian golden hamsters, and guinea pigs. NDMM induces tumors in the esophagus in rats, pancreatic cancer in hamsters, and hemangioendothelial tumors of the liver in guinea pigs. An intragastric dose of NDMM (2 mg, 2 muCi/animal) was rapidly distributed throughout the tissues of both the rat and hamster, with no apparent accumulation of radioactivity in any one tissue. At low dose levels, NDMM was metabolized rapidly by both species. The hamster appeared to metabolize the compound faster than did the rat or guinea pig. At appreciable amount of radioactivity was excreted in the urine in all three species after 8 hr: approximately 54% in the hamster, 39% in the rat; and 30% in the guinea pig. During the first 24 hr, only a small percentage of the radioactivity excreted by the hamster, rat, and guinea pig was NDMM (0.8, 2, and 0.5%, respectively). High-pressure liquid chromatography analysis of urine collected 24 hr after administration revealed 12 metabolites. Although the urinary metabolites appeared to be similar in all three species, one large difference was the presence of a major urinary metabolite in hamster urine, which was absent or present in only small quantities in the rat and guinea pig. The guinea pig urine also had relatively more radioactivity present in one major fraction than did the hamster or rat.
The selling of a foodservice: Bob Underwood beats the competition.
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Environmental noise, perceived control, and aggression.
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Procedings: The conflict between the criminal justice system and addict rehabilitation systems.
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