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Biomedical subjects

T Anderson

Publications and source records attributed to T Anderson.

At least 37 records · Page 2Linked to original sources
PubMed1999

The application of Poisson random-effects regression models to the analyses of adolescents' current level of smoking.

BACKGROUND: In school-based smoking prevention research, it is still debatable whether parents or peers are most influential to maintained smoking among adolescents. As a result, this study examines the effects of parental and peer approval of smoking on adolescents' current levels of smoking. METHODS: Poisson random-effects regression models were used to assess the effects of parental and peer approval of smoking on adolescents' (n = 913) current level of smoking. RESULTS: Results of these analyses indicate that a stronger relationship between parental approval of smoking and current level of smoking was found for female adolescents than for male adolescents. Conversely, a stronger relationship between peer approval of smoking and current level of smoking was found for male adolescents than for female adolescents. With respect to race, the influence of parental approval of smoking on adolescents' current level of smoking was generally more pronounced for minority adolescents, relative to white adolescents. However, the influence of peer approval of smoking on current level of smoking was strongest for white adolescents and was less strong for black, Hispanic, and Asian adolescents. CONCLUSION: The findings of this study demonstrated that the effects of parental and peer approval of smoking on adolescents' current levels of smoking were varied by gender and race. These differential effects may have some implication for the development of future school-based smoking prevention and cessation programs.

Adolescent↗
PubMed1999

Finite beam-width ray model for geometric spectral broadening.

The purpose of the study was to compare measured spectral width and maximum frequency with that predicted from ray models of geometric spectral broadening. Zero and finite beam-width models were used. Spectral data were acquired from a string phantom using two commonly-used linear array systems. Beam width and Doppler aperture sizes were measured using a needle hydrophone. The results showed that the experimentally measured data agreed best with the finite beam-width model. The zero beam-width model was in error by up to 50% for calculated spectral width, and up to 10% for maximum frequency. It is concluded that spectral width and maximum frequency are best calculated using the finite beam-width model, and that ultrasound manufacturers could improve the variation in spectral broadening measured at different locations on a single machine by adjusting the aperture size to give a constant subtended angle and beam width.

Models, Theoretical↗
PubMed1999

Measurement of tissue motion.

A number of ultrasonic methods are available for the detection of tissue motion as it occurs physiologically in the body. The detection of echoes from within the body in less than 1 ms after the initial transmission of ultrasound and the Doppler effect have enabled a range of instrumentation to be developed. The subject owes a great deal to advances in transducer design, electronics and computer technology. Over many years fast B-mode imaging and M-mode traces of boundary position versus time have been the main clinical tools. Currently new sophisticated detection and imaging techniques are being produced based on the Doppler effect and on tracking motion in tissue images. The measurement of several velocity components is permitting velocity vectors to be determined more completely, adding to accuracy. Not surprisingly, cardiology is the main field of application but there are other areas of interest, e.g. vascular, musculo-skeletal and foetal function studies.

Artifacts↗
PubMed1999

Agranulocytosis in Bangkok, Thailand: a predominantly drug-induced disease with an unusually low incidence. Aplastic Anemia Study Group.

Agranulocytosis, a syndrome characterized by a marked reduction in circulating granulocytes, is strongly associated with medical drug use in Europe and the United States. Unregulated use of common pharmaceutical agents in developing countries has been suspected of causing large numbers of cases of agranulocytosis and deaths, especially among children. To elucidate the incidence and etiology of agranulocytosis in Thailand, a population-based case-control study of symptomatic agranulocytosis that resulted in hospital admission was conducted in Bangkok from 1990 to 1994. An attempt was also made to study the disease in Khonkaen (in northeastern Thailand) and Songkla (in southern Thailand), but there were insufficient cases in the latter regions, and the analysis was confined to subjects from Bangkok. In that region, the overall incidence of agranulocytosis was 0.8 per million per year; there were no deaths. As expected, the incidence was higher in females (0.9 per million), and it increased with age (4.3 per million beyond age 60). Among 25 cases and 529 controls the relative risk estimate for a combined category of all suspect drugs was 9.2 (95% confidence interval = 3.9-21), and the proportion of cases that could be attributed to drug use was 68%. For individual drugs and drug classes the data were sparse; within these limitations, the strongest association appeared to be with antithyroid drugs. One case and three controls were exposed to dipyrone, a drug known to cause agranulocytosis; with such scanty data the risk could not be evaluated. Exposure to pesticides or solvents was not associated with an increased risk. This is the first formal epidemiologic study of agranulocytosis in a developing country. As in the West, most cases are attributable to medical drug use. However, the incidence of agranulocytosis in Bangkok, and apparently, in Thailand as a whole, is unusually low, and the disease does not pose a public health risk.

Adolescent↗
PubMed1999

BANFF: an update.

Data from the Brachial Artery Normalization of Forearm Function (BANFF) trial indicate that angiotensin-converting enzyme (ACE) inhibitors and other vasoactive substances appear to differ in their ability to improve endothelial dysfunction. Only quinapril, which is a lipophilic ACE inhibitor with high affinity for tissue ACE, produced a significant improvement in flow-mediated brachial artery dilation in coronary artery disease patients; enalapril, losartan and amlodipine did not. Quinapril showed highly significant improvement in subjects with one copy of the insertion allele, either the ACE-ID or the ACE-II genotype. It is anticipated that the effects of QUinapril On Vascular ACE and Determinants of ISchemia (QUO VADIS) trial will further differentiate ACE inhibitors (quinapril versus captopril) according to their effects on vascular tissue taken from pretreated patients undergoing coronary artery bypass graft surgery.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1999

Merger, they wrote.

When senior executives at Grant and Riverside Methodist Hospitals in Columbus, OH, decided to merge their institutions into one healthcare system, the two security forces suddenly were faced with the need for major changes. The directors of the two security departments decided to work together to plot a successful integration strategy and to protect the security staff in the bargain. By involving staff in organization decisions, they made integration easier.

Decision Making, Organizational↗