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Biomedical subjects

B Thompson

Publications and source records attributed to B Thompson.

At least 19 recordsLinked to original sources

Presenting characteristics as predictors of duration of treatment in sarcoidosis.

BACKGROUND: Some sarcoidosis patients never need therapy, but many still require therapy more than 2 years after initial diagnosis. AIM: To determine what features at initial presentation are associated with treatment 2 years later. METHODS: Patients with biopsy-confirmed sarcoidosis enrolled in the ACCESS (A Case Control Etiologic Study of Sarcoidosis) study were initially evaluated within 6 months of diagnosis. Pulmonary function, chest X-ray and dyspnoea score were measured, and systemic therapy for the sarcoidosis recorded. Organ involvement was assessed using a standardized instrument. A subset (n = 215) were seen 18-24 months later for follow-up, and these patients constitute our study group. RESULTS: Ten patients had only received therapy before the first visit, with no further therapy, and were excluded from analysis. Of the remaining 205, 95 were not on therapy at the initial visit and 75 (79%) of these were never treated during follow-up. Of the 110 initially on therapy, 52 (47%) remained on therapy at follow-up. Other initial features associated with continued therapy were the level of dyspnoea and predicted vital capacity. On logistic regression, only dyspnoea and therapy at initial visit remained significant. Patients on systemic therapy at initial evaluation were more likely to be on therapy at follow-up (OR 3.6, p = 0.003). Neither ethnicity nor gender independently predicted therapy at follow-up. DISCUSSION: This study group represents a sample of newly diagnosed sarcoidosis patients. However, this is a referral population, and there was no set protocol for treatment. Use of systemic therapy within the first 6 months after diagnosis appears to be strongly associated with continued use of therapy 2 years later.

Adult↗

Prospective endoscopic evaluation for gastrointestinal graft-versus-host disease: determination of the best diagnostic approach.

The best endoscopic diagnostic strategy for gastrointestinal (GI) graft-versus-host disease (GVHD) is unknown. Over a 48-month period, all patients with unexplained diarrhea at risk for acute gastrointestinal GVHD were prospectively identified. Acute GVHD was defined as symptoms and histologic evidence of GVHD occurring within 100 days of transplant or donor lymphocyte infusion (DLI). Colonoscopy was performed with multiple biopsies of the ileum, right colon and rectosigmoid colon. Next, upper endoscopy with duodenal and random gastric biopsies of both antrum and body were performed. All biopsies were evaluated for GVHD by an experienced GI pathologist. Over the study period, 24 patients (mean age 37 years; 62.5% male) were evaluated. The median time from transplantation or DLI was 30.5 days. The biopsy site with the highest yield was the distal colon (82%). A combination of upper endoscopy with sigmoidoscopy and colonoscopy with ileal biopsies were equivalent ( approximately 94%). In patients with diarrhea at risk for GVHD, biopsies of the distal colon had the highest diagnostic yield suggesting the importance of sigmoidoscopy and biopsy. Colonoscopy and ileoscopy or flexible sigmoidoscopy plus upper endoscopy had the highest diagnostic yields.

Adolescent↗

Indoor air quality risk factors for severe lower respiratory tract infections in Inuit infants in Baffin Region, Nunavut: a pilot study.

Inuit infants have extremely high rates of lower respiratory tract infection (LRTI), but the causes for this are unclear. The aims of this study were to assess, in young Inuit children in Baffin Region, Nunavut, the feasibility of an epidemiologic study of the association between indoor air quality (IAQ) and respiratory health; to obtain data on IAQ in their housing; and to identify and classify risk factors for LRTI. Twenty houses in Cape Dorset, Nunavut with children below 2 years of age, were evaluated using a structured housing inspection and measurement of IAQ parameters, and a respiratory health questionnaire was administered. Twenty-five percent of the children had, at some time, been hospitalized for chest illness. Houses were very small, and had a median of six occupants per house. Forty-one percent of the houses had a calculated natural air change rate <0.35 air changes per hour. NO(2) concentrations were within the acceptable range. Smokers were present in at least 90% of the households, and nicotine concentrations exceeded 1.5 microg/m(3) in 25% of the dwellings. Particulates were found to be correlated closely with nicotine but not with NO(2) concentrations, suggesting that their main source was cigarette smoking rather than leakage from furnaces. Mattress fungal levels were markedly increased, although building fungal concentrations were low. Dust-mites were virtually non-existent. Potential risk factors related to IAQ for viral LRTI in Inuit infants were observed in this study, including reduced air exchange and environmental tobacco smoke exposure. Severe lower respiratory tract infection is common in Inuit infants. We found reduced air change rates and high occupancy levels in houses in Cape Dorset, which may increase the risk of respiratory infections. This suggests the measures to promote better ventilation or more housing may be beneficial. Further health benefits may be obtained by reducing bed sharing by infants and greater turnover of mattresses, which were found to have high levels of fungi.

Air Pollutants↗

A 93 year old man with the PRSS1 R122H mutation, low SPINK1 expression, and no pancreatitis: insights into phenotypic non-penetrance.

BACKGROUND: The cationic trypsinogen (PRSS1) R122H mutation causes autosomal dominant hereditary pancreatitis (HP) with multiple attacks of acute pancreatitis, but the penetrance, frequency, and severity of attacks are highly variable. HP twins study suggests that modifier genes influence severity but not penetrance. AIM: To investigate potential trypsin associated factors in subjects with the PRSS1 R122H mutation and phenotypic non-penetrance. METHODS: Two subjects from HP families (including a 93 year old subject with PRSS1 R122H without pancreatitis), one with chronic pancreatitis and one with a normal pancreas, were studied. Relative expression of: (a) the PRSS1 R122 and H122 alleles; and (b) the PRSS1 and SPINK1 genes in pancreatitis were determined using complementary methods. RESULTS: PRSS1 wild-type (R122) and mutant (H122) allele expression was equivalent in multiple (> 3) samples from the phenotypically affected and non-penetrant subjects with R122H genotypes using allele specific quantitative reverse transcription-polymerase chain reaction (RT-PCR) and intron spanning nested RT-PCR followed by cDNA sequencing. Compared with PRSS1 mRNA levels, SPINK1 mRNA levels were low in normal appearing tissue but markedly increased in samples with chronic inflammation, independent of PRSS1 genotype. CONCLUSION: Attacks of acute pancreatitis in HP subjects appear to be independent of the relative expression of the mutant PRSS1 H122 allele or SPINK1 gene expression. The marked increase in SPINK1 gene expression with inflammation is consistent with its regulation as an acute phase protein.

Aged, 80 and over↗

Journal clubs.

Explore the source record for details and available documents.

Dental Research↗

The antinociceptive effect of acupressure in rats.

Acupuncture and acupressure points correlate well with sites on the body that have low transcutaneous electrical resistance (TER). Using lightly sedated, adult Sprague-Dawley rats, we identified an acupoint (i.e. site with low TER) located on the hind limb of the rat and compared the effects of acupressure at this site on the nociceptive threshold to an adjacent, non-acupoint site (i.e. site with high TER). Focal pressure (55.42 +/- 2.2 g) was applied to the site for 10 minutes and the tail flick response (TFR) was determined by draping the distal portion of the tail over a heated wire (75 +/- 5 degrees C). Three trials were performed during each of three randomized conditions (i.e. acupoint, placebo and control) and the trials were averaged. All rats tested (5/5) showed a statistically significant increase in TFR following 10 minutes of acupressure at the acupoint compared to placebo or control trials (p = 0.007). Acupressure at the placebo point resulted in a TFR that was not statistically different from the control. Systemic administration of naloxone completely abolished the tail-flick inhibition induced by acupressure at the acupoint. These data suggest that acupressure elicits an antinociceptive effect in rats that is mediated by the endogenous release of opioids.

Acupressure↗

Patterns of antipsychotic utilization in a tertiary care psychiatric institution.

OBJECTIVE: To perform a retrospective survey of discharge medications at a tertiary care psychiatric facility in an attempt to gain insight into, and perhaps an understanding of, the most recent pattern of antipsychotic utilization in patients with a diagnosis not restricted to schizophrenia. METHODS: This is a retrospective survey that used the Department of Pharmacy's computer database to obtain relevant discharge information on all non-geriatric patients discharged from Riverview Hospital between 1 January and 31 December 2000. The records of 372 patients met the inclusion criteria and formed the database for the survey. RESULTS: The results of this survey revealed a relatively high prevalence of antipsychotic polypharmacy (the use of two antipsychotics). Perhaps surprisingly, the highest rate of antipsychotic polypharmacy was found in individuals diagnosed with schizoaffective disorder (49.3%), followed by schizophrenia (44.7%), bipolar disorder (29.9%), and psychosis not otherwise specified (22.5%). CONCLUSION: Although antipsychotic polypharmacy is not a new phenomenon in schizophrenia, this study is the first to document its employment among other diagnoses.

Adult↗

Defining the sports medicine specialist in the United Kingdom: a Delphi study.

OBJECTIVE: To define the role and responsibilities of the sports medicine specialist using a recognised research technique. METHODS: A Delphi technique was employed using anonymous postal questionnaires sent to a random sample of 300 members of the British Association of Sport and Exercise Medicine. The questionnaire of 300 putative attributes was developed in a pilot study and the Delphi technique used allowed participants to modify their responses according to the responses of other participants. RESULTS: There was a 53% response to both rounds of the study with 75.6% of the respondents being male, 39% having a higher qualification in sports medicine, and 45.6% being general practitioners. Some 86.3% strongly agreed that sport and exercise medicine should be a recognised speciality and 90% strongly agreed that it should be available on the National Health Service (NHS). The most important specialist attributes were orthopaedic and soft tissue medicine (83.6% strongly agreed) and emergency medical management (79.7% strongly agreed). More than 75% of respondents did not agree that either research or personal playing experience were relevant. CONCLUSION: Sports and exercise medicine is an evolving speciality in the United Kingdom. We believe this is the first systematic attempt to define the role and responsibilities of the sports medicine specialist and the findings are of relevance to the future development of a career pathway.

Attitude of Health Personnel↗

A prospective study of household smoking bans and subsequent cessation related behaviour: the role of stage of change.

OBJECTIVE: To assess the degree to which smokers living with a full household ban on smoking change their cessation related behaviour. DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study; follow up of a population based cohort of 1133 smokers, identified from a 1997 telephone survey of adult Oregonians. After a median of 21 months, 565 were located and reinterviewed. MAIN OUTCOME MEASURES: Quit attempts, time until relapse, and smoking cessation, defined as seven day and 90 day sustained abstinence at follow up. RESULTS: A full ban at baseline was associated with a doubling of the odds of a subsequent quit attempt (odds ratio (OR) = 2.0, 95% confidence interval (CI), 1.0 to 3.9). Among respondents in the preparation stage at baseline (intention to quit in the next month with a quit attempt in the previous year), a full ban was associated with a lower relapse rate (hazard ratio = 0.5 (95% CI, 0.2 to 0.9)), while for those in precontemplation/contemplation (no intention to quit or intention to quit within the next six months, respectively), there was no significant association between full ban and relapse rate. For respondents in preparation, those with a full ban had over four times the odds of being in cessation for seven or more days before the follow up call (OR = 4.4 (1.1 to 18.7)), but for those in precontemplation/contemplation, full bans were unrelated to cessation. CONCLUSIONS: Full household bans may facilitate cessation among smokers who are preparing to quit by increasing quit attempts. They may also prolong time to relapse among those smokers.

Adolescent↗

Sarcoidosis: social predictors of severity at presentation.

To determine relationships among social predictors and sarcoidosis severity at presentation, demographic characteristics, socioeconomic status, and barriers to care, A Case-Control Etiologic Study of Sarcoidosis (ACCESS) was set up. Patients self-reported themselves to be Black or White and were tissue-confirmed incident cases aged > or =l8-yrs-old (n=696) who had received uniform assessment procedures within one of 10 medical centres and were studied using standardised questionnaires and physical, radiographical, and pulmonary function tests. Severity was measured by objective disease indicators, subjective measures of dyspnoea and short form-36 subindices. The results of the study showed that lower income, the absence of private or Medicare health insurance, and other barriers to care were associated with sarcoidosis severity at presentation, as were race, sex, and age. Blacks were more likely to have severe disease by objective measures, while women were more likely than males to report subjective measures of severity. Older individuals were more likely to have severe disease by both measures. In conclusion, it was found that low income and other financial barriers to care are significantly associated with sarcoidosis severity at presentation even after adjusting for demographic characteristics of race, sex, and age.

Adult↗

Causes of sediment toxicity to Mytilus galloprovincialis in San Francisco Bay, California.

Since the San Francisco Regional Monitoring Program (RMP) sampling began, elutriate samples prepared with sediment from the Grizzly Bay monitoring station have been consistently toxic to bivalve larvae (Mytilus galloprovincialis). An investigation into the cause of toxicity was initiated with a Phase I Toxicity Identification Evaluation (TIE) using bivalve embryos. TIE results and chemical analyses of elutriate samples suggested that divalent metals were responsible for the observed toxicity. Following the initial characterization of trace metals as toxicants, additional TIEs were performed on elutriates prepared from three additional Grizzly Bay samples collected between 1997 and 2001. Additional TIEs included ethylenediamine tetraacetic acid (EDTA) treatments in a sediment-water interface (SWI) exposure system, and the use of a cation exchange column with serial elution of sample fractions with hydrochloric acid of increasing normality. EDTA significantly reduced toxicity in overlying water in the SWI system. The cation exchange column reduced both toxicity and concentrations of trace metals, and serial elution of the column added back both toxicity and specific metals contained in individual acid fractions. Chemical analyses of three elutriate samples demonstrated copper concentrations were within the range toxic to bivalves. Results of Phase I TIEs, additional Phase II treatments, SWI exposures, and metals analyses indicate the potential for metal toxicity in sediments from this estuarine site. When combined with the results of standard TIE methods, a solid-phase cation extraction and elution approach identified copper as the most probable cause of toxicity.

Animals↗

Translational regulation of the plant S-adenosylmethionine decarboxylase.

It is becoming apparent that control of protein synthesis by metabolites is more common than previously thought. Much of that control is exerted at the level of initiation of mRNA translation, orchestrated by upstream open reading frames (uORFs) and RNA secondary structure. S-Adenosylmethionine decarboxylase (AdoMetDC) is a key enzyme in polyamine biosynthesis and both mammalian and plant AdoMetDCs are translationally regulated by uORFs in response to polyamine levels by distinct mechanisms.

Adenosylmethionine Decarboxylase↗

chy1, an Arabidopsis mutant with impaired beta-oxidation, is defective in a peroxisomal beta-hydroxyisobutyryl-CoA hydrolase.

The Arabidopsis chy1 mutant is resistant to indole-3-butyric acid, a naturally occurring form of the plant hormone auxin. Because the mutant also has defects in peroxisomal beta-oxidation, this resistance presumably results from a reduced conversion of indole-3-butyric acid to indole-3-acetic acid. We have cloned CHY1, which appears to encode a peroxisomal protein 43% identical to a mammalian valine catabolic enzyme that hydrolyzes beta-hydroxyisobutyryl-CoA. We demonstrated that a human beta-hydroxyisobutyryl-CoA hydrolase functionally complements chy1 when redirected from the mitochondria to the peroxisomes. We expressed CHY1 as a glutathione S-transferase (GST) fusion protein and demonstrated that purified GST-CHY1 hydrolyzes beta-hydroxyisobutyryl-CoA. Mutagenesis studies showed that a glutamate that is catalytically essential in homologous enoyl-CoA hydratases was also essential in CHY1. Mutating a residue that is differentially conserved between hydrolases and hydratases established that this position is relevant to the catalytic distinction between the enzyme classes. It is likely that CHY1 acts in peroxisomal valine catabolism and that accumulation of a toxic intermediate, methacrylyl-CoA, causes the altered beta-oxidation phenotypes of the chy1 mutant. Our results support the hypothesis that the energy-intensive sequence unique to valine catabolism, where an intermediate CoA ester is hydrolyzed and a new CoA ester is formed two steps later, avoids methacrylyl-CoA accumulation.

Amino Acid Sequence↗

Mode of delivery and postpartum morbidity among HIV-infected women: the women and infants transmission study.

Cesarean delivery before onset of labor and rupture of membranes (i.e., scheduled cesarean delivery) is associated with a lower risk of vertical transmission of HIV. The following a priori hypotheses were tested: among HIV-infected women, scheduled cesarean delivery is associated with a higher risk of postpartum morbidity, longer hospitalization, and a higher risk of rehospitalization than spontaneous vaginal delivery. Postpartum morbidity occurred following 178 of 1,186 (15%) of deliveries during 1990 to 1998 in The Women and Infants Transmission Study. The most commonly reported postpartum morbidity events were: fever without infection, hemorrhage or severe anemia, endometritis, urinary tract infection, and cesarean wound complications. Several time trends were observed: the median duration of ruptured membranes decreased (p < .001), intrapartum antibiotic use increased (p < .001), the median antepartum plasma HIV RNA concentration decreased (p < .001), and the incidence of any postpartum morbidity decreased (p = .02). With spontaneous vaginal delivery as the reference category, both scheduled (odds ratio [OR] = 4.69; 95% confidence interval [95% CI], 2.03-10.84), and nonscheduled (OR, 2.50; 95% CI, 1.24-5.04) cesarean deliveries were associated with fever without infection; with urinary tract infection (OR, 3.79; 95% CI 1.04-13.85; OR, 3.86; 95% CI, 1.55-9.60, respectively), and with any postpartum morbidity (OR, 3.19; 95% CI 1.69-6.00; OR, 4.10; 95% CI, 2.71-6.19, respectively). Nonscheduled cesarean deliveries were more likely to be complicated by endometritis (OR, 6.98; 95% CI, 3.53-13.78). Adjusted ORs relating mode of delivery and each of the outcomes (fever without infection, urinary tract infection, endometritis, and any postpartum morbidity) were similar to unadjusted ORs. Results of this analysis indicate scheduled cesarean delivery is associated with an increased risk of any postpartum morbidity and, specifically, postpartum fever without infection. The potential for postpartum morbidity with scheduled cesarean delivery should be considered in light of possible adverse events associated with other interventions to decrease the risk of vertical transmission of HIV. Counseling of HIV-infected pregnant women regarding scheduled cesarean delivery as a possible intervention to decrease maternal-infant transmission of HIV should include discussion of these results, as well as new data as they become available, regarding the incidence and severity of postpartum morbidity events among HIV-infected women according to mode of delivery.

Cesarean Section↗

Seattle 5 a Day worksite program to increase fruit and vegetable consumption.

BACKGROUND: 5 a Day for Better Health is a simple message encouraging people to eat more fruits and vegetables. The Seattle 5 a Day worksite investigators designed and evaluated an intervention, organized on stages of behavioral change, to increase worksitewide fruit and vegetable consumption. METHODS: We recruited 28 worksites with cafeterias and randomized 14 to intervention and 14 to control. The intervention addressed both changes in the work environment and individual level behavior change. In each worksite, an employee advisory board, with study interventionist assistance, implemented the program. By surveying cross-sectional samples of 125 employees per worksite, we compared worksite mean fruit and vegetable consumption at 2-year follow-up with that at baseline. Unobtrusive site-level indicators including plate observation and cafeteria checklist were also used. RESULTS: The difference at 2 years was 0.5 for the intervention worksites and 0.2 for the control worksites, with an intervention effect of 0.3 daily serving (P < 0.05). Other measures of fruit and vegetable consumption, including unobtrusive indicators, supported the effectiveness of the intervention. CONCLUSIONS: This simple 5 a Day intervention is feasible and acceptable for use in worksites with cafeterias. There was a significant differential increase in fruit and vegetable consumption in the intervention worksites. This kind of worksite intervention can achieve important health benefits on a population basis, because of its potential to reach large numbers of people.

Adult↗

The Raynaud's Treatment Study: biofeedback protocols and acquisition of temperature biofeedback skills.

The Raynaud's Treatment Study (RTS) compared temperature biofeedback training and a behavioral control procedure (frontalis EMG biofeedback) with nifedipine-XL and a medication placebo for treatment of primary Raynaud's phenomenon (RP) in a large (N = 313) multicenter trial. The present study describes the RTS biofeedback protocols and presents data on the acquisition of digital skin temperature and frontalis EMG responses in the RTS. The findings point to substantial problems with acquisition of physiological self-regulation skills in the RTS. Only 34.6% of the Temperature Biofeedback group (N = 81) and 55.4% of the EMG Biofeedback group (N = 74) successfully learned the desired physiological response. In contrast, 67.4% of a Normal Temperature Biofeedback group (N = 46) learned hand warming. Multivariate analysis found that coping strategies, anxiety, gender, and clinic site predicted acquisition of hand-warming skills whereas variables related to RP disease severity did not. Physiological data showed vasoconstriction in response to the onset of biofeedback and also found that performance in the initial sessions was critical for successful acquisition. These findings indicate that attention to the emotional and cognitive aspects of biofeedback training, and a degree of success in the initial biofeedback sessions, are important for acquisition.

Adult↗

The late open artery hypothesis--a decade later.

BACKGROUND: Early reperfusion after myocardial infarction has been proved to preserve left ventricular function and reduce mortality. However, a significant number of patients have persistent occlusion of the infarct-related artery late (days to weeks) after myocardial infarction because of ineligibility for thrombolytic therapy, failure of reperfusion, or reocclusion. METHODS: In this report we review the data on the potential mechanisms and benefits of late reperfusion and present prospective data on the incidence of and current practice patterns for the management of persistently occluded infarct-related arteries late after myocardial infarction. RESULTS: Although several studies have associated late patency of the infarct-related artery with improved long-term clinical outcome, they were nonrandomized and reflect selection bias. Furthermore, data on late patency from the largest study, Global Utilization of Steptokinase and Tissue Plasminogen Activator for Occluded Arteries (GUSTO-I), failed to confirm independent benefits of an open infarct-related artery 1 year after myocardial infarction. The randomized data on the effects of percutaneous transluminal coronary angioplasty for occluded infarct-related arteries late after myocardial infarction are limited and inconclusive. CONCLUSIONS: The hypothesis that late reperfusion by percutaneous coronary intervention days to weeks after myocardial infarction results in improved long-term clinical outcomes in asymptomatic patients with occluded infarct-related artery is currently being tested in the randomized, multicenter Occluded Artery Trial.

Clinical Trials as Topic↗

Cardiac and respiratory activity at arousal from sleep under controlled ventilation conditions.

Arousal from sleep is associated with elevated cardiac and respiratory activity. It is unclear whether this occurs because of homeostatic mechanisms or a reflex activation response associated with arousal. Cardiorespiratory activity was measured during spontaneous arousals from sleep in subjects breathing passively on a ventilator. Under such conditions, homeostatic mechanisms are eliminated. Ventilation, end-tidal PCO2, mask pressure, diaphragmatic electromyograph, heart rate, and blood pressure were measured in four normal subjects under two conditions: assisted ventilation and a normal ventilation control condition. In the control condition, there was a normal, sleep-related fall in ventilation and rise in end-tidal PCO2. Subsequently, at an arousal, there was an increase in respiratory and cardiac activity. In the ventilator condition, a vigorous cardiorespiratory response to a spontaneous arousal from sleep remained. These results indicate that sleep-related respiratory stimuli are not necessary for the occurrence of elevated cardiorespiratory activity at an arousal from sleep and are consistent with the hypothesis that such activity is at least in part due to a reflex activation response.

Adult↗