Search PubMed⌕ Search

Biomedical subjects

James P Smith

Publications and source records attributed to James P Smith.

13 recordsLinked to original sources
PubMed2003

Overdiagnosis in chest radiographic screening for lung carcinoma: frequency.

BACKGROUND: The pattern of results in the Mayo Lung Project (MLP), which is the basis for the prevailing recommendations against radiographic screening for lung carcinoma, has led to the assertion that up to 50% of the diagnosed cases of early-stage disease in that trial may have represented overdiagnosed, indolent cases. This finding suggests the possibility of such a high frequency of overdiagnosis in chest radiographic lung carcinoma screening in general. In the current study, the authors analyzed data from the MLP and its counterpart study at Memorial Sloan-Kettering Cancer Center (MSK) to estimate the frequency of overdiagnosis in these studies. METHODS: For the cases diagnosed as Stage I in the MLP and the MSK studies, the doubling times of tumor volumes were calculated. The calculations were based on size measurements recorded by the original investigators from chest radiographs taken during the course of each study. RESULTS: The median doubling times were 101 days in the MLP and 144 days in the MSK, times that are somewhat shorter than those reported in published series of adenocarcinoma cases diagnosed outside screening, and only 5% had doubling times exceeding 400 days. CONCLUSIONS: The hypothesis that early-stage lung tumors diagnosed on chest radiography during lung carcinoma screening may frequently be overdiagnosed, indolent cases needs to be rejected.

Adenocarcinoma↗
PubMed2003

Effect of ethanol on the growth of Clostridium botulinum.

Model broth studies were carried out to investigate the effect of ethanol on the growth of proteolytic (group I) strains of Clostridium botulinum. Ethanol extended the pathogen's lag phase, decreased its exponential growth rate, and decreased its final level of growth in the stationary phase. In all cases, botulinum neurotoxin production was associated with growth. Micrographs of C. botulinum cultures grown at 37 degrees C in trypticase peptone glucose yeast extract (TPGY) broths containing 2 and 4% ethanol showed elongation of vegetative cells and interference with cell division. The inhibition of growth and toxin production at the ethanol level predicted (5.5%, wt/wt) was confirmed by microscopy and by the mouse bioassay. A subsequent study was carried out to determine the combined effect of ethanol (0 to 8% [wt/wt]), water activity (aw; 0.953 to 0.997), and pH (6.2 to 8.2) on the probability of the growth of and neurotoxin production by proteolytic strains of C. botulinum (10(3) spores per ml). Growth and neurotoxin production occurred in 1 to 3 days in TPGY broths without ethanol (0%) and in 2 to 4 days in broths containing 2% ethanol regardless of the aw or pH levels (P < 0.005). Growth and neurotoxin production were delayed by an ethanol concentration of 4% ethanol and completely inhibited by a concentration of 6%. At an ethanol concentration of 4%, the probability of growth and toxin production over 365 days (Pt) was influenced by aw and pH. After 365 days, the maximum probability of growth and toxin production (Pmax) was 1 for all but one combination. However, tau, the time it took for 50% of all eventually positive replicates for any given combination of barriers to show growth and/or turbidity, ranged from <3 to 229 days. All tubes of TPGY broths that showed no growth after 365 days were subcultured in fresh TPGY broths. In all cases, growth and toxin production occurred within 24 h at 37 degrees C, indicating the reversible (sporostatic and/or bacteriostatic) effect of ethanol on C. botulinum.

Botulinum Toxins↗
PubMed2002

Can patient self-management help explain the SES health gradient?

There are large differences in health outcomes by socioeconomic status (SES) that cannot be explained fully by traditional arguments, such as access to care or poor health behaviors. We consider a different explanation-better self-management of disease by the more educated. We examine differences by education in treatment adherence among patients with two illnesses, diabetes and HIV, and then assess the subsequent impact of differential adherence on health status. One unique component of this research is that for diabetes we combine two different surveys-one cohort study and one randomized clinical trial-that are usually used exclusively by either biomedical or/and social scientists separately. For both illnesses, we find significant effects of adherence that are much stronger among patients with high SES. After controlling for other factors, more educated HIV+ patients are more likely to adhere to therapy, and this adherence made them experience improvements in their self-reported general health. Similarly, among diabetics, the less educated were much more likely to switch treatment, which led to worsening general health. In the randomized trial setting, intensive treatment regimens that compensated for poor adherence led to better improvements in glycemic control for the less educated. Among two distinct chronic illnesses, the ability to maintain a better health regimen is an important independent determinant of subsequent health outcomes. This finding is robust across clinical trial and population-based settings. Because this ability varies by schooling, self-maintenance is an important reason for the steep SES gradient in health outcomes.

Adolescent↗
PubMed2002

Mammographic screening: no reliable supporting evidence?

Much confusion is being generated by the conclusion of a recent review that "there is no reliable evidence that screening for breast cancer reduces mortality." In that review, however, there was no appreciation of the appropriate mortality-related measure of screening's usefulness; and correspondingly, there was no estimation of the magnitude of this measure. We take this measure to be the proportional reduction in case-fatality rate, and studied its magnitude on the basis of the only valid and otherwise suitable trial. We found reliable evidence of fatality reduction, apparently substantial in magnitude.

Breast Neoplasms↗
PubMed2002

Effects of end-of-month admission on length of stay and quality of care among inpatients with myocardial infarction.

PURPOSE: We studied whether transfer of care when house staff and faculty switch services affects length of stay or quality of care among hospitalized patients. SUBJECTS AND METHODS: We performed a retrospective analysis in 976 consecutive patients admitted with myocardial infarction from 1995 to 1998. Patients who were admitted within 3 days of change in staff were denoted end-of-month patients. RESULTS: Of 782 eligible patients, 690 (88%) were admitted midmonth and 92 (12%) at the end of the month. The median length of stay was 7 days for midmonth and 8 days for end-of-month patients (P = 0.06). End-of-month admission was an independent predictor of length of stay in multivariate models. In addition, a significant difference in length of stay was noted between patients admitted at the beginning and end of the academic year. There were no statistically significant differences in the use of aspirin, beta-blockers, angiotensin-converting enzyme inhibitors, or lipid-lowering agents at discharge between midmonth and end-of-month patients. Mortality and in-hospital adverse events did not differ between the two groups, with the possible exception of a greater incidence of acute renal failure in the end-of-month patients. CONCLUSIONS: Although admission during the last 3 days of the month is an independent predictor of length of stay, it does not have a large effect on quality of care among patients with myocardial infarction.

Cardiology Service, Hospital↗
PubMed2002

Computed tomography screening for lung cancer.

The development of CT technology reopened the lung cancer screening debate. Computed tomography screening for lung cancer certainly meets all the criteria required for an appropriate screening test. First and perhaps most importantly, the disease for which the screening is being performed should have a significant prevalence in the population being studied and be a significant health risk for those afflicted with it. Lung cancer is the leading cause of cancer death in both men and women, and one of the most lethal of all cancers.

Adenocarcinoma↗
PubMed1984

Nuclear weapons.

Explore the source record for details and available documents.

Delivery of Health Care↗