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Biomedical subjects

G J Martin

Publications and source records attributed to G J Martin.

At least 73 records · Page 4Linked to original sources
PubMed1994

Conservation and ethnobotanical exploration.

In recent years conservationists have realized that the maintenance of protected areas is closely linked to rural development. As part of their efforts to improve local people's standards of living, they have sought the advice of researchers who work in communities, especially those that border on nature reserves. Ethnobotanists, who are turning their attention to the cultural and ecological crises confronting the regions in which they work, are natural allies in this venture. The joint efforts of conservationists and ethnobotanists are being supported by non-profit organizations, intergovernmental agencies and research institutes. The search for new drugs and other natural products from plants is an important element in this collaboration, but it cannot be divorced from the broader objective of promoting the survival of biological and cultural diversity. Conservationists will support biodiversity prospecting and related efforts only if there is a clear benefit for local communities and protected areas. An example of the concrete actions being taken by conservation agencies is the People and Plants Initiative, a joint effort of the World Wide Fund for Nature, the United Nations Educational, Scientific and Cultural Organization and the Royal Botanic Gardens, Kew. The main objective is to support the work of ethnobotanists in developing countries in studies of sustainable plant use and application of their work to conservation and community development. The initiative provides training workshops and relevant literature; coordinators work in collaboration with local people to create inventories of useful plants and appraise the impact of harvesting specific plant resources in and around protected areas. Phytochemical screening of medicinal plants and preparation of extracts are carried out as part of some projects.

Conservation of Natural Resources↗
PubMed1994

First-year residents' caring, medical knowledge, and clinical judgment in relation to laboratory utilization.

PURPOSE: To investigate first-year residents' levels of caring (concern for others' well-being), medical knowledge, and clinical judgment in relation to their levels of laboratory utilization. METHOD: Self-report questionnaires about caring, knowledge, and judgment were given in 1986-87 to 36 first-year residents in a three-year internal medicine residency program of the McGaw Medical Center of Northwestern University. Inpatient laboratory utilization data obtained from structured chart audits over a one-year period were used to construct comparable diagnosis- and severity-specific physician practice profiles, from which the residents received overall utilization scores for laboratory test charges. Statistical methods included Cronbach's alpha reliability coefficient and multiple regression analysis. RESULTS: The multiple regression analysis showed that medical knowledge was an independent predictor of increased laboratory utilization (standardized beta = .54, p < .04, partial R2 = .07); clinical judgment was an independent predictor of decreased utilization (standardized beta = -.53, p < .05, partial R2 = .06); and caring was unrelated to utilization (standardized beta = .15, ns, partial R2 = .01). CONCLUSION: The finding that clinical judgment was related to less laboratory utilization suggests that future research should investigate the decision-making concomitants of judgment to better understand its translation into resource utilization. It is possible that the relationship between medical knowledge and laboratory utilization is developmentally specific, and thus the knowledge of more experienced physicians, who would likely be more precise decision makers than first-year residents, may be related to decreased rather than increased utilization.

Chicago↗
PubMed1994

ST segment depression detected by continuous electrocardiography in patients with acute ischemic stroke or transient ischemic attack.

BACKGROUND AND PURPOSE: Forty percent of patients with a history of ischemic stroke or transient ischemic attack (TIA) have concomitant coronary artery disease. ST segment depression, detected by continuous electrocardiography, is associated with increased cardiac morbidity and mortality in patients with known coronary artery disease. While electrocardiographic changes have been associated with acute stroke, the etiology and significance of these changes remain unclear. In this pilot study we report the prevalence of ST segment depression and ventricular arrhythmias in patients with acute ischemic stroke or TIA monitored by continuous electrocardiography. Clinical predictors of ST segment depression and ventricular arrhythmia are also identified. METHODS: Consecutive patients presenting with acute ischemic stroke or TIA were enrolled within 72 hours of hospital admission and monitored by continuous electrocardiography for 48 hours. The electrocardiographic results were analyzed for periods of ST segment depression and ventricular arrhythmias. RESULTS: Of 51 patients with ischemic stroke or TIA, 15 (29%) had episodes of ST segment depression (95% confidence interval, 15% to 43%), and 18 (35%) had ventricular arrhythmias (95% confidence interval, 21% to 49%). In logistic regression analysis, increasing age (P < .02) and a left-sided neurological event (P < .01) were significant predictors of ST segment depression. Increasing numbers of atherosclerotic risk factors, a history of cardiac disease, and increasing or decreasing mean arterial pressure were not predictive of ST segment depression. CONCLUSIONS: Patients with acute ischemic stroke or TIA have a 29% prevalence of ST segment depression within the first 5 days after their event. In comparison, the prevalence of ST depression is 2.5% to 8% in asymptomatic adults and 43% to 60% in patients with symptomatic coronary artery disease. The association of ST segment depression with left-sided neurological events suggests that the electrocardiographic changes are in part neurologically mediated. Further study is necessary to better define the brain-heart interaction and to determine whether ST segment depression in patients with ischemic stroke or TIA reflects underlying coronary artery disease.

Acute Disease↗
PubMed1993

Predicting survival from in-hospital CPR: meta-analysis and validation of a prediction model.

OBJECTIVE: To better clarify patient factors that predict survival from in-hospital cardiopulmonary resuscitation (CPR), using two methods: 1) meta-analysis and 2) validation of a prediction model, the pre-arrest morbidity (PAM) index. DESIGN: Meta-analysis of previously published studies by standard techniques. Retrospective chart review of validation sample. SETTING: University-affiliated teaching hospital. PATIENTS/PARTICIPANTS: Meta-analytic sample of 21 previous studies from 1965-1989. The validation sample consisted of all patients surviving resuscitation from the authors' hospital during the period September 1986 to January 1991. A matched sample of patients who did not survive from the same time period was used as the comparison group. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The strongest negative predictors of survival, by meta-analysis, were renal failure (r = 0.088, p < 0.0002), cancer (r = 0.08, p < 0.0002), and age more than 60 years (r = 0.063, p < 0.006). Sepsis (r = 0.046, p < 0.02), recent cerebrovascular accident (CVA) (r = 0.038, p < 0.04), and congestive heart failure (CHF) class III/IV (r = 0.036, p < 0.05) were weaker negative predictors. Presence of acute myocardial infarction (AMI) was a significant positive predictor of survival (r = 0.15, p < 0.0001). The PAM score was highly predictive of survival in a logistic regression model (p < 0.0003, R2 = 9.6%). No patient who survived to discharge had a PAM score higher than 8. CONCLUSION: Meta-analysis reveals that the most significant negative predictors of survival from CPR are renal failure, cancer, and age more than 60 years, while AMI is a significant positive predictor. The PAM index is a useful method of stratifying probability of survival from CPR, especially for those patients with high PAM scores, who have essentially no chance of survival.

Age Factors↗
PubMed1993

Use of the Rand Structured Implicit Review Instrument for Quality of Care Assessment.

The Rand Structured Implicit Review Instrument is a 27-item instrument that rates process quality of care for patients with five common illnesses. This study reports on the use of this instrument for hospitalized patients with long lengths of stay. A total of 120 medical records were reviewed by multiple physician reviewers for patients discharged with congestive heart failure, acute myocardial infarction, and pneumonia. Mean inter-rater reliability was assessed for a subsample of six records by kappa score. A multiple regression analysis was used to estimate the relationship between process ratings for the quality of documentation, assessment, monitoring, and therapy and overall quality of care scores, controlled for physician judgments about patients' prognosis and selected patient characteristics. Each reviewer also evaluated the instrument. Mean kappa for trichotomized ratings of quality of care was 0.50. The majority of all quality of care ratings were in the good or very good range (77.5%). The full regression model, including process subscale quality ratings, prognostic items, and patient characteristics, accounted for 38% of the total variance in the quality of care ratings. Items measuring the quality of assessment (p < 0.0001), therapy (p < 0.02) and monitoring (p < 0.01) were significant. Physicians accepted the use of such a form moderately well. The Rand quality of care form shows consistency in rating overall quality of care and individual dimensions of quality. Achieving a high level of inter-rater reliability is difficult with implicit review. By focusing on specific areas of potentially deficient care, structured review instruments can improve clinical quality improvement efforts.

Humans↗
PubMed1993

Androgyny predicts empathy for trainees in medicine.

Data from 65 medical students and residents support the hypothesis that scores on a measure of androgyny are predictive of those on an index of empathy but relatively modest predictive accuracy was observed for sympathetic responses. Further exploration is suggested.

Adult↗
PubMed1993

Prognosis after graft replacement operation for abdominal aortic aneurysm.

We analyze findings on the long-term survival of patients undergoing elective graft replacement operations for abdominal aortic aneurysm. We review the principal surgical case series published in peer-reviewed, English-language journals over the past 15 years. Preoperative mortality was 4.0%, and 5-year survival was 69% in 16 reviewed studies encompassing 4,288 patients. Articles on late survival have largely focused on the preoperative assessment of coronary artery disease in patients who are candidates for aortic resection. The influence of other recognized risk factors, such as advanced age, hypertension, cerebrovascular disease, congestive heart failure, diabetes mellitus, and multiple aneurysms, is often not well specified in these studies. As a greater number of older patients with abdominal aortic aneurysm are seen with serious associated disease, knowledge about the expected survival of patients with surgically treated aneurysms is becoming more important to both primary care physicians and vascular surgeons when eliciting patient preferences for surgical treatment.

Age Factors↗
PubMed1992

Axial distances in discrete Möbius groups.

We describe here new lower bounds for the trace of the commutator of a discrete two-generator group of Möbius transformations. These results lead to sharp estimates for the distance between the axes of elliptics in a discrete group and hence to new bounds for the volume of hyperbolic manifolds and orbifolds that will be discussed elsewhere.

Journal Article↗
PubMed1992

Iatrogenic complications in high-risk, elderly patients.

BACKGROUND: This study explores the quality improvement potential of reviewing care for long-stay, elderly medicine service patients hospitalized for congestive heart failure, acute myocardial infarction, or pneumonia at a large Midwestern teaching hospital. METHODS: Medical records were reviewed for 120 patients aged 65 years or older who were discharged between January 1987 and June 1989, with hospital stays of 15 days or longer. Patients' severity of illness on admission was rated using the Medicare Mortality Predictor System; process quality of care was rated using a structured implicit review form for judging several dimensions of clinical assessment and decision making. Serious complications were coded by etiology and type and judged as possibly or probably preventable. Logistic regression was used to identify risk factors for iatrogenic events; multiple regression was used to assess potential outcome bias in ratings of overall quality of care. RESULTS: Of 120 medical records reviewed, 70 (58.3%) suffered at least one iatrogenic complication. Forty-three patients (35.8%) suffered an iatrogenic complication rated as potentially preventable. Significant predictors of all iatrogenic complications were quality ratings of initial physician assessment, patients' inability to walk unassisted, and low Glasgow Coma Score. For potentially preventable complications, quality ratings for physician documentation of functional status were also significant. Ratings for overall quality of care were not significantly influenced by the mere presence of death or complications. CONCLUSIONS: Iatrogenic complications are likely to be an extremely common experience for elderly medicine service patients with long lengths of stay. A significant portion of these complications may be potentially preventable with closer attention to initial assessment and documentation of patients' functional status.

Aged↗
PubMed1991

Reproducibility and relation to mean heart rate of heart rate variability in normal subjects and in patients with congestive heart failure secondary to coronary artery disease.

Before heart rate (HR) variability can be used for predictive purposes in the clinical setting, day-to-day variation and reproducibility need to be defined as do relations to mean HR. HR variability and mean HR were therefore determined in 2 successive 24-hour ambulatory electrocardiograms obtained from 33 normal subjects (age 34 +/- 7 years, group I), and 22 patients with coronary disease and stable congestive heart failure (CHF) (age 59 +/- 7 years, group II). Three measures were used: (1) SDANN (standard deviation of all mean 5-minute normal sinus RR intervals in successive 5-minute recording periods over 24 hours); (2) SD (the mean of the standard deviation of all normal sinus RR intervals in successive 5-minute recording periods over 24 hours); and (3) CV (coefficient of variation of the SD measure), a new measure that compensates for HR effects. Group mean HR was higher and HR variability lower in group II than in group I (80 +/- 10 vs 74 +/- 9 beats/min, p less than 0.04). Mean group values for HR and HR variability showed good correlations between days 1 and 2 (mean RR, r = 0.89, 0.97; SDANN, r = 0.87, 0.87; SD, r = 0.93, 0.97; CV, r = 0.95, 0.97 in groups I and II, respectively). In contrast, considerable individual day-to-day variation occurred (group I, 0 to 46%; group II, 0 to 51%). Low HR variability values were more consistent than high values. SDANN and SD correlated moderately with HR in both groups (r = 0.50 to 0.64). The CV measure minimizes HR effects on HR variability.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Determination of site-specific carbon isotope ratios at natural abundance by carbon-13 nuclear magnetic resonance spectroscopy.

Site-specific natural isotope fractionation of hydrogen studied by deuterium NMR (SNIF-NMR) spectroscopy is a powerful source of information on hydrogen pathways occurring in biosyntheses in natural conditions. The potential of the carbon counterpart of this method has been investigated and compared. Three typical molecular species, ethanol, acetic acid, and vanillin, have been considered. Taking into account the requirements of quantitative 13C NMR, appropriate experimental procedures have been defined and the repeatability and reproducibility of the isotope ratio determinations have been checked in different conditions. It is shown that the carbon version of the SNIF-NMR method is capable of detecting small differences in the carbon-13 content of the ethyl fragment of ethanols from different botanical or synthetic origins. These results are in agreement with mass spectrometry determinations of the overall carbon isotope ratios. Deviations with respect to a statistical distribution of 13C have been detected in the case of acetic acid and vanillin. However, since the method is very sensitive to several kinds of systematic error, only a relative significance can be attached at present to the internal parameters directly accessible. Isotope dilution experiments have also been carried out in order to check the consistency of the results. In the present state of experimental accuracy, the 13C NMR method is of more limited potential than 2H SNIF-NMR spectroscopy. However it may provide complementary information. Moreover it is particularly efficient for detecting and quantifying adulterations that aim to mimic the overall carbon-13 content of a natural compound by adding a selectivity enriched species to a less expensive substrate from a different origin.

Acetates↗
PubMed1991

The factor structure and cross-sectional distributional properties of the Beth Israel/UCLA Functional Status Questionnaire.

The functional status of ambulatory patients is an important correlate of their emotional and physical well-being and is subject to influence by the delivery of health care. First, the present study obtains a profile on the FSQ for a large sample of young, healthy adults (N = 508 college undergraduates), for use as an "empirical standard" against which to evaluate the effect of disease or injury on an individual's functional status. Second, cross-sectional analyses contrast distributional features of responses to the FSQ between (a) the present younger, healthy sample and (b) a previously published, older ambulatory patient sample. These analyses suggest that the FSQ has acceptable discriminant validity for intergroup comparisons. Finally, confirmatory structural analyses suggest that the theoretical six-factor model hypothesized to underlie responses to the FSQ has a modest, yet acceptable, goodness of fit to actual data.

Activities of Daily Living↗