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Biomedical subjects

T Thompson

Publications and source records attributed to T Thompson.

At least 55 records · Page 3Linked to original sources
PubMed2000

Clinicopathological study of oligodendroglial tumors: the effectiveness of interferon beta, ACNU/MCNU, and radiation (IAR/IMR) for anaplastic tumors.

The retrospective clinicopathological characteristics of oligodendroglial tumors were investigated in patients who underwent surgery, radiotherapy, and/or chemotherapy. Regarding oligodendroglioma and oligoastrocytoma without malignancy, patients who had undergone radiation therapy at a total dose of 40-50Gy had relatively long postoperative survival. Of these 15 patients, 6 showed signs of recurrence, and after additional treatment, 5 patients are still alive. On the other hand, regarding anaplastic oligodendroglial tumors, patients with anaplastic oligoastrocytoma responded well to combination chemotherapy with interferon beta, nitrosourea derivatives (ACNU/ MCNU), and radiation therapy (referred to as IAR/IMR) and survived longer than patients with anaplastic oligodendroglioma. In conclusion, patients with oligodendroglial tumors could survive longer by treatment involving surgery and radiotherapy. As for malignancy, cases of anaplastic oligoastrocytoma could be effectively treated by adjuvant therapy using IAR/IMR after surgery, but in cases of anaplastic oligodendroglioma, the response to IAR/IMR was not good, and another strategy of treatment should be recommended.

Adolescent↗
PubMed2000

Acclimation response of spring wheat in a free-air CO(2) enrichment (FACE) atmosphere with variable soil nitrogen regimes. 1. Leaf position and phenology determine acclimation response.

We have examined the photosynthetic acclimation of wheat leaves grown at an elevated CO(2) concentration, and ample and limiting N supplies, within a field experiment using free-air CO(2) enrichment (FACE). To understand how leaf age and developmental stage affected any acclimation response, measurements were made on a vertical profile of leaves every week from tillering until maturity. The response of assimilation (A) to internal CO(2) concentration (C(i)) was used to estimate the in vivo carboxylation capacity (Vc(max)) and maximum rate of ribulose-1,5-bisphosphate limited photosynthesis (A (sat)). The total activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), and leaf content of Rubisco and the Light Harvesting Chlorophyll a/b protein associated with Photosystem II (LHC II), were determined. Elevated CO(2) did not alter Vc(max) in the flag leaf at either low or high N. In the older shaded leaves lower in the canopy, acclimatory decline in Vc(max) and A (sat) was observed, and was found to correlate with reduced Rubisco activity and content. The dependency of acclimation on N supply was different at each developmental stage. With adequate N supply, acclimation to elevated CO(2) was also accompanied by an increased LHC II/Rubisco ratio. At low N supply, contents of Rubisco and LHC II were reduced in all leaves, although an increased LHC II/Rubisco ratio under elevated CO(2) was still observed. These results underscore the importance of leaf position, leaf age and crop developmental stage in understanding the acclimation of photosynthesis to elevated CO(2) and nutrient stress.

Journal Article↗
PubMed2000

Intellectual characteristics of Prader-Willi syndrome: comparison of genetic subtypes.

Advances in genetics have led to an increased understanding of the role of the genotype on behavioural functioning. The purpose of the present study was to examine differences in intellectual functioning in individuals with Prader-Willi syndrome (PWS) with a paternal 15q11-q13 deletion versus maternal uniparental disomy (UPD) of chromosome 15. Measures of intelligence and academic achievement were administered to 38 individuals with PWS (24 with deletion and 14 with UPD). The subjects with UPD had significantly higher verbal IQ scores than those with deletion (P< 0.01). The magnitude of the difference in verbal IQ was 9.1 points (69.9 versus 60.8 for UPD and deletion PWS subjects, respectively). Only 17% of subjects with the 15q11-q13 deletion had a verbal IQ > or = 70, while 50% of those with UPD had a verbal IQ > or = 70. Performance IQ scores did not differ between the two PWS genetic subtype groups. This is the first report to document the difference between verbal and performance IQ score patterns among subjects with PWS of the deletion versus the UPD subtype.

Adolescent↗
PubMed2000

Impact of azithromycin on oropharyngeal carriage of group A Streptococcus and nasopharyngeal carriage of macrolide-resistant Streptococcus pneumoniae.

BACKGROUND: Invasive group A streptococcal (GAS) infections are a cause of serious morbidity and high mortality. There is a need for a simple, effective antimicrobial regimen that could be used to prevent invasive GAS disease in high risk situations. To assess azithromycin as a chemoprophylactic agent, we evaluated its efficacy for eradication of oropharyngeal (OP) GAS and its impact on the nasopharyngeal (NP) colonization rate of macrolide-resistant Streptococcus pneumoniae. METHODS: We obtained OP and NP swabs for GAS and pneumococcus culture, respectively, from 300 schoolmates of a child with an invasive GAS infection. GAS culture-positive students were treated with daily azithromycin (12 mg/kg/day) for 5 days. We obtained follow-up OP and NP swabs at 9 (Day 17) and 24 (Day 32) days post-treatment from those students identified as GAS carriers on Day 0 and determined macrolide susceptibility of GAS and pneumococcal isolates. RESULTS: Of the 300 students swabbed 152 (50%) carried GAS in their oropharynx. On Day 17, efficacy of azithromycin for GAS eradication was 95% (140 of 147) for all students. NP colonization rates for pneumococci decreased from 46% (67 of 146) to 12% (17 of 144; P < 0.001) by Day 17 and to 20% (27 of 137; P < 0.001) by Day 32. The prevalence of erythromycin-resistant pneumococcal isolates increased from 2% (3 of 146) to 4% (6 of 144) by Day 17 and to 8% (11 of 137; P = 0.04) by Day 32. CONCLUSIONS: Azithromycin is an effective short course regimen for eradication of oropharyngeal GAS. However, azithromycin selected for macrolide-resistant strains of pneumococci. These findings highlight the importance of determining the appropriate circumstances for antimicrobial prophylaxis to prevent invasive GAS infections.

Anti-Bacterial Agents↗
PubMed1999

Influence of age on outcome after percutaneous transluminal coronary angioplasty.

This study estimates the influence of age on outcomes (mainly survival) of 21,516 patients who underwent percutaneous transluminal coronary angioplasty (PTCA) between 1980 and 1996. We prospectively analyzed the patients in 5 age groups: <50, 50 to 59, 60 to 69, 70 to 79, and > or =80 years old. During the in-hospital period after PTCA, mortality increased from 0.28% in patients aged <50 to 3.45% in patients aged > or =80; Q-wave myocardial infarction was not significantly associated with age, and the 2 older groups were referred less often to coronary artery bypass graft surgery. During follow-up, lasting up to 10 years, the hazard of death was significantly influenced by age; Q-wave myocardial infarction was influenced by age, although the magnitude of the effect was relatively small and of questionable clinical significance; and coronary artery bypass graft surgery was performed less often in the 2 older age groups. Additional PTCA was similarly performed among the age groups. Age, diabetes mellitus, systemic hypertension, heart failure class, angioplasty in graft vessel, number of coronary vessels narrowed, and previous myocardial infarction were predictors of death over the 10-year follow-up. Age was the most important correlate of death after PTCA, with a 65% increase in the hazard of death for each 10-year increase in age. Age has an independent effect on early and late survival after PTCA.

Age Distribution↗
PubMed1999

Predictive ability of social cognitive theory in exercise research: an integrated literature review.

The mechanisms that underlie successful initiation and adherence to physical activity regimens are not well understood. Few theoretical models have used consistent explanatory variables that are theory-driven and many findings that use extant models are equivocal. Social Cognitive Theory (SCT) as presented by Bandura (1986, 1997) appears to have strong promise as a guide to understanding physical activity behaviors and developing clinically relevant interventions to promote the initiation and maintenance of physical activity. This critical systematic review of research using SCT was completed to determine the predictive ability of model constructs in explaining physical activity behavior and in identifying key intervention components found to enhance physical activity initiation and maintenance. Following review for quality and adequacy, published research during the years 1990-1998 contained 27 studies that examined the relationship between the construct of SCT, self-efficacy, and physical activity. All of the descriptive studies found a statistically significant relationship between self-efficacy and exercise behavior. Intervention studies demonstrated that participation in an exercise program promoted self-efficacy, and that programs designed to increase outcome expectations and self-efficacy significantly increased exercise behavior. Due to the centrality of self-efficacy in many of the social psychological theories that help explain the attitude-intention-behavior triad, a strong need remains to design interventions to maximize its usefulness. Clear, generalizable, systematic and theoretically comprehensive, randomized, controlled studies are needed to understand the usefulness of the construct.

Journal Article↗
PubMed1999

Description of the postcloacal glands of Plethodon cinereus, the red-backed salamander, during bouts of scent marking.

Plethodon cinereus, the red-backed salamander, is a small territorial vertebrate that defends refugia located on the forest floor. As a component of territorial defense, these animals use scent marks to advertise their refugia. Behavioral evidence indicates that scent marks are produced by the postcloacal glands located on the ventral surface of the tail just posterior to the cloaca. We placed animals on unmarked substrates and recorded changes in serous acini from the postcloacal and shoulder region over a 48-h period. Within the first hour there was an increase in the number of acini filled with secretory product in the postcloacal region. At 12 h the number of full acini decreased and the number of empty acini increased. By 24 h the number of empty acini had decreased and the number of renewing acini containing secretory cells producing product had increased. By 48 h the ratio of full to empty to renewing acini was similar to those observed at the start of the study. In the shoulder region, no significant changes in the ratio of full to empty to renewing acini were observed. Observations of the serous acini within the postcloacal region and the shoulder region indicate that the mode of secretory production is holocrine. These findings are additional evidence that the postcloacal glands are the site of scent mark production.

Animals↗
PubMed1999

Development and validation of a measurement system for assessment of energy expenditure and physical activity in Prader-Willi syndrome.

OBJECTIVE: The morbid obesity associated with Prader-Willi syndrome (PWS) may result from either excessive energy intake or reduced energy expenditure (EE). In this report, we describe the development and validation of an Activity-Energy Measurement System (AEMS) to measure EE and physical activity components in an environment approximating free-living conditions. RESEARCH METHODS AND PROCEDURES: The AEMS consists of a live-in, whole-room indirect calorimeter equipped with a novel force platform floor system to enable simultaneous measurements of EE, physical activity, and work efficiency during spontaneous activities and standardized exercises. Free-living physical activity and estimated free-living EE are measured using portable triaxial accelerometers individually calibrated in each subject during their stay in the AEMS. RESULTS: Representative data from two PWS patients and two matched control (CTR) subjects displayed EE during their inactive lifestyles. DISCUSSION: This combination of methods will allow the quantification of daily EE and its components, the amount and energy cost of physical activity, and the relationships between body composition and EE, in order to determine their roles in the development and maintenance of the morbid obesity in PWS.

Adolescent↗
PubMed1999

The relative cost of outpatient telemedicine services.

OBJECTIVE: This study compares the costs of offering outpatient care to primarily orthopedic and dermatology patients via live, interactive telemedicine to the estimated costs of direct face-to-face care for the same patients. MATERIALS AND METHODS: A simple, yet detailed methodology was used to evaluate the cost of adding telemedicine to a health care delivery system, using a "hub-and-spoke" model located in Minnesota. The costs and cost savings of telemedicine were evaluated from the perspectives of patients, providers, insurers, employers, and society as a whole. Sensitivity analysis was used to investigate the impact of various factors on the model. RESULTS: The variable cost of a telemedicine referral was $144, versus an estimated face-to-face referral cost of $183. Reductions in patient travel costs and in lost employee productivity were the principal benefits of the system. The break-even point, where total costs equal total cost savings, equalled 1,449 consultations annually. Sensitivity analyses indicated that the breakeven point varies from a low of 152 telemedicine consultations for a "best case" scenario to no possible breakeven point for a "worst case" scenario. CONCLUSIONS: At the system's current level of 300 consultations per year, the telemedicine system is estimated to add $45,000 to society's costs of providing medical care for these patients. The additional cost is primarily due to personnel expenses and an increase in the volume of specialty care. Patients see specialists more often due to improved access to care and lower transportation costs. Providers bear the cost while patients and employers enjoy substantial savings.

Ambulatory Care↗
PubMed1999

Architectural acoustics in residences for adults with mental retardation and its relation to perceived homelikeness.

Previous investigators examined how architectural features of residences for adults with mental retardation contributed to the visual appearance of homelikeness. Acoustical characteristics of 18 residences for people with mental retardation were examined here. As part of a concurrent study, college undergraduates rated photographs of rooms in each house for their apparent homelikeness. Reverberation times in living and dining rooms were negatively correlated with mean homelikeness ratings. The less homelike rooms had reverberation times that may interfere with speech perception for some people and that were comparable with those found in larger public rooms (e.g., lecture halls). The larger reverberation times in these rooms were the result of insufficient sound absorption by these rooms' furnishings.

Acoustics↗
PubMed1999

Self-injurious behavior and Prader-Willi syndrome: behavioral forms and body locations.

With few exceptions (e.g., Lesch-Nyhan syndrome), the specific nature of self-injury in relation to identified genetic syndromes associated with mental retardation is poorly understood. In the present study we surveyed the families of 62 persons with Prader-Willi syndrome to determine the prevalence, topographies, and specific body locations of self-injurious behavior. Self-injury was reported for 81% of the participants. Skin-picking was the most prevalent form, with the front of the legs and head being disproportionately targeted as preferred self-injury body sites. Individuals with the 15q11-q13 deletion injured significantly more body sites than did individuals with maternal disomy 15. Results are discussed in relation to previous self-injury body site findings and implications for the relevance of syndrome-specific behavioral phenotypes.

Adolescent↗
PubMed1999

Managing year 2000 (Y2K) compliance in the medical practice.

It is the responsibility of every medical practice to examine the year 2000 compliance of all medical devices, facilities, and computer systems that it uses, and whether external business partners are also taking appropriate steps in this area. You need a plan, and you need to start right now.

Computers↗