ABSTRACT
The authors surveyed 614 African American university students to determine the magnitude of cigarette use, identify risk factors, and develop models to predict smoking. More than half (58.3%) of the participants had smoked at least once, and 9.3% of that group were lifetime smokers. Among the lifetime smokers, 71.3% had smoked during the 30 days preceding the survey. More women (66.8%) than men (56.1%) had tried smoking and were classed as lifetime smokers. Residence, parental, and peer smoking (current and childhood) were associated with trying smoking; age, race/ethnicity, and marital status were additional factors for becoming a lifetime smoker. The risk of being a lifetime smoker was reduced when neither friends nor parents of the student smoked and the student viewed spirituality as important. The results of this study add to the growing understanding of health risk behaviors among African Americans and can be useful in reducing smoking.
Subject(s)
Black or African American/statistics & numerical data , Health Behavior/ethnology , Smoking/epidemiology , Students/statistics & numerical data , Universities/statistics & numerical data , Adolescent , Adult , Black or African American/psychology , Female , Humans , Logistic Models , Male , Prevalence , Risk-Taking , Students/psychology , United States/epidemiologyABSTRACT
There are many types of rigid internal fixation devices available for podiatric surgery. The cannulated screw system is an easy and effective way to decrease surgical time. These screws are being used with great success for several rearfoot procedures, such as the triple arthrodesis, Dwyer calcaneal osteotomy, and posterior malleolar ankle fractures.
Subject(s)
Arthrodesis , Bone Screws , Calcaneus/surgery , Osteotomy , Ankle Injuries , Arthrodesis/methods , Fractures, Bone/surgery , Humans , Osteotomy/methods , TitaniumABSTRACT
Hfr- and P1-mediated genetic transfer experiments failed to confirm the presence of a " minA " gene in Escherichia coli K-12, leading to the conclusion that mutation at a single locus, the minB locus, is sufficient to cause minicell production in this species.
Subject(s)
Escherichia coli/genetics , Genes, Bacterial , Crosses, Genetic , DNA Restriction Enzymes , Species SpecificityABSTRACT
In earlier studies we reported that 6-hydroxymethylbenzo[alpha]pyrene is a metabolite of benzo[alpha]pyrene and of 6-methylbenzo[alpha]pyrene when these substrates are incubated with homogenates or microsomal preparations of liver and microsomal preparations of subcutaneous tissue from Sprague--Dawley rats. However, the origin of the carbon donor was not established. We now report that S-adenosyl-L-methionine (SAM) can serve as a carbon donor in the metabolic formation of 6-hydroxymethylbenzo[alpha]pyrene from benzo[alpha]pyrene by the S-9 fraction of rat liver.
Subject(s)
Benzopyrenes/metabolism , Microsomes, Liver/metabolism , S-Adenosylmethionine/metabolism , Animals , Benzo(a)pyrene , Biotransformation , Chemical Phenomena , Chemistry , Chromatography, High Pressure Liquid , Male , Rats , Rats, Inbred StrainsABSTRACT
The carcinogenic hydrocarbons 6-hydroxymethylbenzo[a]pyrene (6-HOCH2-B[a]P) and 6-acetoxymethylbenzo[a]pyrene (6-AcOCH2-B[a]P) were examined for their ability to bind to rat and calf thymus DNA. The data indicate there are no appreciable differences in the amount of binding to the two types of DNA. Non-enzymatic binding of 6-HOCH2-B[a]P was low (5 mumol hydrocarbon/mol DNA P) but 6-AcOCH2-B[a]P was bound to a considerable extent (88.4--97.3 mumol hydrocarbon/mol DNA P). Non-enzymatic binding of 6-HOCH2-B[a]P was greatly increased in the presence of ATP. Binding of 6-HOCH2-B[a]P in the presence of liver microsomes from untreated rats or from rats pretreated with 3-methylcholanthrene (3-MC) never exceeded 5 mumol hydrocarbon/mol DNA P. Binding of 6-HOCH2-B[a]P in the presence of a PAPS generating system was less than non-enzymatic binding mediated by ATP and was dependent on the presence of ATP rather than ATP and sulfate. Binding was reduced by 50% when ADP was employed in the non-enzymatic reaction and was negligible in the presence of AMP or adenosine, indicating that a diphosphate group is necessary. Incubation of 6-HOCH2-B[a]P with DNA in the presence of ATP, CTP, GTP, or UTP showed that ATP was the most effective mediator of the binding reaction. These observations suggest that 6-HOCH2-B[a]P is converted to a phosphate ester which, like 6-AcOCH2-B[a]P, is much more reactive than 6-HOCH2-B[a]P itself.
Subject(s)
Benzopyrenes/metabolism , DNA/metabolism , Adenine Nucleotides/pharmacology , Animals , Cattle , In Vitro Techniques , Male , Microsomes, Liver/metabolism , Rats , Thymus Gland/metabolismABSTRACT
Female Sprague-Dawley rats were given a subcutaneous injection of the parent hydrocarbon or its K-region epoxide in 0.1 ml sesame oil on alternate days to a total of 30 doses and observed for sarcoma at the site of injection for 275 days. The parent compounds, benzo(a)pyrene (0.2 mumole/dose) and 7,12-dimethylbenz(a)anthracene (0.2 mumole/dose), induced sarcoma in 100% of the animals with an average latent period of 101 and 95 days, respectively, whereas five of 12 rats (42%) injected with the K-region epoxide of B(a)P (1.0 mumole/dose), developed sarcoma in 151+/-22 days, and the K-region epoxide of DMBA (0.4 mumole/dose) failed to elicit tumors. Under these experimental conditions, these K-region epoxides are, at best, only weak carcinogens.
