Search PubMed⌕ Search

Biomedical subjects

L Green

Publications and source records attributed to L Green.

At least 91 records · Page 5Linked to original sources
PubMed1997

Rate of temporal discounting decreases with amount of reward.

The present, subjective value of a delayed reward is a decreasing function of the duration of the delay. This phenomenon is termed temporal discounting. To determine whether the amount of the reward influences the rate of temporal discounting, we had subjects choose between immediate and delayed hypothetical rewards of different amounts ($100, $2,000, $25,000, and $100,000 delayed rewards). As predicted by psychological models of the choice process, hyperbolic functions described the decrease in the subjective value of the delayed reward as the time until its receipt was increased (R2s from .86 to .99). Moreover, hyperbolic functions consistently provided more accurate descriptions of the data than did exponential functions predicted by an economic model of discounted utility. Rate of discounting decreased in a negatively accelerated fashion as the amount of the delayed reward increased, leveling off by approximately $25,000. These findings are interpreted in the context of different psychological models of choice, and implications for procedures to enhance self-control are discussed.

Adolescent↗
PubMed1997

Ultraviolet radiation, melanocytic naevi and their dose-response relationship.

Melanocytic naevi on the face and neck of 110 Brisbane secondary school students aged 16-17 years were mapped according to specified regions to investigate the dose-response relationship between ultraviolet (UV) radiation and melanocytic naevi. Highest naevus density occurred in regions receiving a mean UV dose of 0.2-0.4 relative to the vertex while densities were low in minimally and maximally exposed regions. This pattern of naevus distribution was unaffected by sex or phenotypic features such as skin colour or degree of freckling. These findings suggest that there is a narrow dose range over which UV radiation can effectively promote the proliferation of melanocytes. A comparison of the regional distribution of naevi on the face and neck with that of solar keratoses appearing over 1 year on the heads of residents of a neighbouring town has shown them to differ significantly. This study may shed some light on the unknown, yet expectedly complex, relation of UV radiation to melanocytic naevi.

Adolescent↗
PubMed1997

What alters physicians' decisions to admit to the coronary care unit?

BACKGROUND: A trial of a decision-support tool to modify utilization of the coronary care unit (CCU) failed because utilization improved after explanation of the tool but before its actual employment in the trial. We investigated this unexpected phenomenon in light of an emerging theory of decision-making under uncertainty. METHODS: A prospective trial of the decision-support intervention was performed on the Family Practice service at a 100-bed rural hospital. Cards with probability charts from the acute ischemic Heart Disease Predictive Instrument (HDPI) were distributed to residents on the service and withdrawn on alternate weeks. Residents were encouraged to consult the probability charts when making CCU placement decisions. The study decision was between placement in the CCU and in a monitored nursing bed. Analyses included all patients admitted during the intervention trial year for suspected acute cardiac ischemia (n = 89), plus patients admitted in two pretrial periods (n = 108 and 50) and one posttrial period (n = 45). RESULTS: In the intervention trial, HDPI use did not affect CCU utilization (odds ratio 1.046, P > .5). However, following the description of the instrument at a departmental clinical conference, CCU use markedly declined at least 6 months before the intervention trial (odds ratio 0.165, P < .001). Simply in learning about the instrument. residents achieved sensitivity and specificity equal to the instrument's optimum, whether or not they actually used it. CONCLUSIONS: Physicians introduced to a decision-support tool achieved optimal CCU utilization without actually performing probability estimations. This may have resulted from improved focus on relevant clinical factors identified by the tool. Teaching simple decision-making strategies might effectively reduce unnecessary CCU utilization.

Acute Disease↗
PubMed1996

Think big!

Explore the source record for details and available documents.

Community Health Planning↗
PubMed1996

A gene map of the human genome.

The human genome is thought to harbor 50,000 to 100,000 genes, of which about half have been sampled to date in the form of expressed sequence tags. An international consortium was organized to develop and map gene-based sequence tagged site markers on a set of two radiation hybrid panels and a yeast artificial chromosome library. More than 16,000 human genes have been mapped relative to a framework map that contains about 1000 polymorphic genetic markers. The gene map unifies the existing genetic and physical maps with the nucleotide and protein sequence databases in a fashion that should speed the discovery of genes underlying inherited human disease. The integrated resource is available through a site on the World Wide Web at http://www.ncbi.nlm.nih.gov/SCIENCE96/.

Amino Acid Sequence↗
PubMed1996

Teenagers' knowledge of emergency contraception: questionnaire survey in south east Scotland.

OBJECTIVE: To determine the level of knowledge of emergency contraception among 14 and 15 year olds. DESIGN: Confidential questionnaire survey. SETTING: 10 secondary schools in Lothian, south east Scotland. SUBJECTS: 1206 pupils predominantly (98.7%) aged 14 and 15 in the fourth year of secondary school. MAIN OUTCOME MEASURES: Knowledge of the existence of emergency contraception; of its safety, efficacy, and time limits; and of where to obtain it. RESULTS: 1121 (93.0%) fourth year pupils aged 14-16 had heard of emergency contraception. 194 girls (32.7%) and 168 boys (27.5%) had experienced sexual intercourse. Of girls who had experienced sexual intercourse, 61 (31.4%) had used emergency contraception. Knowledge of correct time limits was poor, sexually active girls being the most knowledgeable. Pupils attending schools ranked lower than the national average for academic attainment were less likely to have heard of emergency contraception and more likely to have been sexually active. 861 (76.8%) pupils knew they could obtain emergency contraception from their doctor. 925 (82.5%) pupils believed emergency contraception to be effective but 398 (35.5%) thought it more dangerous than the oral contraceptive pill. CONCLUSIONS: One third of sexually active girls aged under 16 in Lothian have used emergency contraception. This may help explain the fairly constant teenage pregnancy rates despite increasing sexual activity. Scottish teenagers are well informed about the existence of emergency contraception. However, many do not know when and how to access it properly. Health education initiatives should target teenagers from less academic schools as they are more likely to be sexually active at a young age and are less well informed about emergency contraception.

Adolescent↗
PubMed1996

Preventing medication errors in cancer chemotherapy.

Recommendations for preventing medication errors in cancer chemotherapy are made. Before a health care provider is granted privileges to prescribe, dispense, or administer antineoplastic agents, he or she should undergo a tailored educational program and possibly testing or certification. Appropriate reference materials should be developed. Each institution should develop a dose-verification process with as many independent checks as possible. A detailed checklist covering prescribing, transcribing, dispensing, and administration should be used. Oral orders are not acceptable. All doses should be calculated independently by the physician, the pharmacist, and the nurse. Dosage limits should be established and a review process set up for doses that exceed the limits. These limits should be entered into pharmacy computer systems, listed on preprinted order forms, stated on the product packaging, placed in strategic locations in the institution, and communicated to employees. The prescribing vocabulary must be standardized. Acronyms, abbreviations, and brand names must be avoided and steps taken to avoid other sources of confusion in the written orders, such as trailing zeros. Preprinted antineoplastic drug order forms containing checklists can help avoid errors. Manufacturers should be encouraged to avoid or eliminate ambiguities in drug names and dosing information. Patients must be educated about all aspects of their cancer chemotherapy, as patients represent a last line of defense against errors. An interdisciplinary team at each practice site should review every medication error reported. Pharmacists should be involved at all sites where antineoplastic agents are dispensed. Although it may not be possible to eliminate all medication errors in cancer chemotherapy, the risk can be minimized through specific steps. Because of their training and experience, pharmacists should take the lead in this effort.

Antineoplastic Agents↗
PubMed1996

Palmar fasciitis and polyarthritis associated with ovarian carcinoma in a young patient. A case report and review of the literature.

Palmar fasciitis and polyarthritis (PFPA) is an uncommon syndrome characterized by progressive and extensive rheumatic disease. It has usually been associated with neoplasms, most commonly in elderly patients, preceding or accompanying the diagnosis of malignancy. We report a case of a 25-year-old patient with severe deforming PFPA preceding the diagnosis of carcinoma of the ovary. The histopathological findings of diffuse fibrosis, connective tissue proliferation and vasculitis with C3 and IgM deposits in subcutaneous tissue and synovia may further clarify the possible pathogenesis of this unique syndrome.

Adult↗
PubMed1996

Recurrent salmonella sepsis with different species in a systemic lupus erythematosus patient.

Infections are a common cause of morbidity and mortality in systemic lupus erythematosus (SLE) patients. The primary disease process and complications of drug management may contribute to this increased susceptibility. A high incidence of salmonella infections have been reported in SLE patients. We report an unusual case of a SLE patient who developed recurrent salmonella sepsis. The first episode with salmonella typhimurium was followed a few months later by an episode of salmonella enteritides sepsis.

Bacteremia↗
PubMed1996

Acute varicella hepatitis in human T-cell lymphotrophic virus types I and II infection.

Varicella (chicken pox) is a common viral infection in children and generally runs a benign course. However, in adults, and especially in immunocompromised subjects such as those on immunosuppressant therapy or with AIDS, varicella infection is particularly severe and is associated with the formation of hemorrhagic skin lesions and visceral involvement. These patients are at an increased risk of developing varicella hepatitis, which frequently results in fulminant hepatic failure and death. In the present report, we describe for the first time the course of disease and the histological appearance of varicella hepatitis in a patient infected with the human T cell lymphotropic viruses (HTLV) I and II; these viruses have many characteristics in common with the human immunodeficiency virus (HIV). Our patient had a relatively benign illness, suggesting that varicella infection in the presence of HTLVI and II may not run as severe a course as it does in patients with HIV infection.

Acyclovir↗
PubMed1996

Temporal discounting in choice between delayed rewards: the role of age and income.

This study examined the effects of age and income temporal discounting (i.e. the decrease in the subjective value of a reward as the delay to its receipt increases). The value of delayed hypothetical monetary rewards was discounted at similar rates by adults of different ages but similar income levels, but at different rates by adults of similar age but different income levels. Specifically, lower income older adults showed a greater degree of temporal discounting than did either upper income older adults or upper income younger adults, but there were no age differences in discounting between the upper income groups. Comparison of these findings with those of a previous study (Green, Fry, & Myerson, 1994) suggests that impulsivity in decision making declines rapidly in young adulthood, reaching stable levels in the 30s. Further, age and income appear to interact in determining the impulsivity of decision making by adults.

Adult↗