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Full-Text Articles in Medicine and Health Sciences

Optimal Survey Design For Community Intervention Evaluations: Cohort Or Cross-Sectional?, Paula Diehr Dec 1995

Optimal Survey Design For Community Intervention Evaluations: Cohort Or Cross-Sectional?, Paula Diehr

Paula Diehr

Community intervention evaluations that measure changes over time may conduct repeated cross-sectional surveys, follow a cohort of residents over time, or (often) use both designs. Each survey design has implications for precision and cost. To explore these issues, we assume that two waves of surveys are conducted, and that the goal is to estimate change in behavior for people who reside in the community at both times. Cohort designs are shown to provide more accurate estimates (in the sense of lower mean squared error) than cross-sectional estimates if (1) there is strong correlation over time in an individual's behavior at …


The Sea Anemone Purine, Caissarone: Adenosine Receptor Antagonism, Roland A. Cooper, Josecarlos De Freitas, Frank Porreca, Cynthia M. Eisenhour, Ronald Lukas, Ryan J. Huxtable Jul 1995

The Sea Anemone Purine, Caissarone: Adenosine Receptor Antagonism, Roland A. Cooper, Josecarlos De Freitas, Frank Porreca, Cynthia M. Eisenhour, Ronald Lukas, Ryan J. Huxtable

Roland A. Cooper

Caissarone, a sea anemone iminopurine, produced an increase in the twitch response of the electrically stimulated guinea-pig ileum-myenteric plexus. In the same assay, caissarone reduced the inhibitory response to the endogenous neuromodulator, adenosine, the A1 adenosine receptor agonist, R-phenylisopropyladenosine (R-PIA), and the A2 agonist, 5'-(N-cyclopropyl)-carboxamidoadenosine (CPCA) in a dose-dependent manner. Schild plot analysis of antagonism by caissarone yielded slopes of near unity, indicating that caissarone acts as a simple competitive antagonist at the adenosine receptor. The dissociation constants (KB) for caissarone ranged from 0.53 mM to 0.78 mM. In functional nicotinic receptor assays in two human cell lines, caissarone failed …


Breaking The Matches In A Paired T-Test For Community Interventions When The Number Of Pairs Is Small, Paula Diehr Jul 1995

Breaking The Matches In A Paired T-Test For Community Interventions When The Number Of Pairs Is Small, Paula Diehr

Paula Diehr

There is considerable interest in community interventions for health promotion, where the community is the experimental unit. Because such interventions are expensive, the number of experimental units (communities) is usually small. Because of the small number of communities involved, investigators often match treatment and control communities on demographic variables before randomization to minimize the possibility of a bad split. Unfortunately, matching has been shown to decrease the power of the design when the number of pairs is small, unless the matching variable is very highly correlated with the outcome variable (in this case, with change in the health behaviour). We …


An "Extended -10" Promoter Alone Directs The Transcription Of The Dpnii Operon Of Streptococcus Pneumoniae, Alexander G. Sabelnikov, Bill Greenberg, Sanford Lacks Apr 1995

An "Extended -10" Promoter Alone Directs The Transcription Of The Dpnii Operon Of Streptococcus Pneumoniae, Alexander G. Sabelnikov, Bill Greenberg, Sanford Lacks

Alexander G Sabelnikov

No abstract provided.


Including Deaths When Measuring Health Status Over Time, Paula Diehr Apr 1995

Including Deaths When Measuring Health Status Over Time, Paula Diehr

Paula Diehr

Measuring health status over time is problematic when some subjects die, because death does not have a defined value on most health status measures. This situation is different from the usual missing data problem because the health status of the dead is, in a sense, known. We examined eight strategies for incorporating deaths into such analyses using three health status measures taken from two data sets, after which we used computer simulation to explore more fully the effect of deaths. The strategies differed in the amount of influence given to the deaths, varying from none (deaths were discarded) to complete …


Population Genetic-Study Among The Orang-Asli (Semai-Senoi) Of Malaysia - Malayan Aborigines, Mary Anne Tan Jin Ai Jan 1995

Population Genetic-Study Among The Orang-Asli (Semai-Senoi) Of Malaysia - Malayan Aborigines, Mary Anne Tan Jin Ai

Mary Anne Tan Jin Ai

A population genetic study was undertaken to provide gene frequency data on the additional blood genetic markers in the Semai and to estimate the genetic relations between the Semai and their neighboring and linguistically related populations by genetic distance and principal components analyses. Altogether 10 poly morphic and 7 monomorphic blood genetic markers (plasma proteins and red cell enzymes) were studied in a group of 349 Senoi Semai from 11. aboriginal settlements (villages) in the Pahang State of western Malaysia, Both the red cell glucosed-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (PGD) loci reveal the presence of polymorphic frequencies of a …


Gene Evolution Of Epoxide Hydrolases And Recommended Nomenclature, Jeffrey K. Beetham, David Grant, Michael Arand, Joan Garbarino, Tomohiro Kiyosue, Franck Pinot, Franz Oesch, William R. Belknap, Kazuo Shinosaki, Bruce D. Hammock Jan 1995

Gene Evolution Of Epoxide Hydrolases And Recommended Nomenclature, Jeffrey K. Beetham, David Grant, Michael Arand, Joan Garbarino, Tomohiro Kiyosue, Franck Pinot, Franz Oesch, William R. Belknap, Kazuo Shinosaki, Bruce D. Hammock

Jeffrey K. Beetham

We have analyzed amino acid sequence relationships among soluble and microsomal epoxide hydrolases, haloacid dehalogenases, and a haloalkane dehalogenase. The amino-terminal residues (1-229) of mammalian soluble epoxide hydrolase are homologous to a haloacid dehalogenase. The carboxy-terminal residues (230-554) of mammalian soluble epoxide hydrolase are homologous to haloalkane dehalogenase, to plant soluble epoxide hydrolase, and to microsomal epoxide hydrolase. The shared identity between the haloacid and haloalkane dehalogenases does not indicate relatedness between these two types of dehalogenases. The amino-terminal and carboxy-terminal homologies of mammalian soluble epoxide hydrolase to. the respective dehalogenases suggests that this epoxide hydrolase, but not the soluble …


Oxidized Low Density Lipoprotein And Lysophosphatidylcholine Stimulation Of Dna Synthesis In Vascular Smooth Muscle Cells Appears Mediated By Basic Fibroblast Growth Factor., Yuh-Cherng Chai, Philip Howe, Paul Dicorletto, Guy Chisolm Dec 1994

Oxidized Low Density Lipoprotein And Lysophosphatidylcholine Stimulation Of Dna Synthesis In Vascular Smooth Muscle Cells Appears Mediated By Basic Fibroblast Growth Factor., Yuh-Cherng Chai, Philip Howe, Paul Dicorletto, Guy Chisolm

Yuh-Cherng Chai

No abstract provided.


Excitatory Amino Acids And Seizures, Michael A. Rogawski Dec 1994

Excitatory Amino Acids And Seizures, Michael A. Rogawski

Michael A. Rogawski

No abstract provided.