Why law pervades medicine: an essay on ethics in health care.
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Biomedical subjects
C Scott
Publications and source records attributed to C Scott.
A phase 3 randomized study of radiotherapy plus procarbazine, CCNU, and vincristine (PCV) with or without BUdR for the treatment of anaplastic astrocytoma: a preliminary report of RTOG 9404.
PURPOSE: This study was an open label, randomized Phase 3 trial in newly diagnosed patients with anaplastic glioma comparing radiotherapy plus adjuvant procarbazine, CCNU, and vincristine (PCV) chemotherapy with or without bromodeoxyuridine (BUdR) given as a 96-hour infusion each week of radiotherapy. METHODS AND MATERIALS: Only patients 18 years or older with newly diagnosed anaplastic glioma were eligible; central pathology review was accomplished, but was not mandated prior to registration. The study had initially opened as a Northern California Oncology Group (NCOG) trial in 1991, becoming an Intergroup RTOG, SWOG, and NCCTG study in July 1994. Total accrual of 293 patients was planned as the sample size, using survival and time to tumor progression as the primary endpoints. The experiment arm (RT/BUdR plus PCV) was to be compared to the control arm (RT plus PCV) using an alpha = 0.05, one-tailed, with a power of 85% for detecting an increase in median survival from 160 to 240 weeks, assuming a 3-year follow-up after completion of enrollment. RESULTS: As of July 1996, 281 patients had been randomized; 53 (20%) were ineligible, primarily based upon central pathology review, and another 39 cases were canceled. In total, 30% of cases were excluded from analysis. The treatment arms were well balanced despite this rate of exclusion. The RTOG Data Monitoring Committee recommended suspension of enrollment in July 1996 based upon a stochastic curtailment analysis which strongly suggested that the addition of BUdR would not be associated with increased survival. In February 1997, the study was closed prior to full enrollment. At that time, the 1-year survival estimates were 82% versus 68% for RT plus PCV and RT/BUdR plus PCV respectively (one-sided, p = 0.96). The conditional power analysis indicated that even with an additional 12 months of additional accrual and follow-up the probability of detecting the prespecified difference was less than 0.01%. The differences in the two arms seem to be due to early deaths in the BUdR arm, not related to toxicity of the treatment. CONCLUSIONS: Despite encouraging Phase 2 results with BUdR, it is unlikely that a survival benefit will be seen. A final study analysis will not be done for at least 3 more years.
Antineoplastic Combined Chemotherapy Protocols↗
The benefit of treatment intensification is age and histology-dependent in patients with locally advanced non-small cell lung cancer (NSCLC): a quality-adjusted survival analysis of radiation therapy oncology group (RTOG) chemoradiation studies.
PURPOSE: Currently, chemoradiation treatment strategies in locally advanced NSCLC are essentially the same irrespective of tumor histology or patient age. The purpose of this study is to analyze the impact of age, histology, Karnofsky performance status (KPS), and specific toxicities on the median survival time (MST) and quality-adjusted survival (QTime) for each treatment strategy. METHODS AND MATERIALS: Nine hundred seventy-nine patients with Stage II-IIIB inoperable NSCLC were enrolled on 6 prospective Phase II and III studies from 1983 to 1995. Treatment regimens ranged from standard RT (SRT) to 60 Gy, hyperfractionated RT (HRT) to 69.6 Gy, induction chemotherapy (ICT) of cisplatin (CIS) and vinblastine (VBL) followed by SRT, ICT + concurrent CT (CCT) + SRT, and CCT + HRT; CCT consisted of etoposide or VBL + CIS. Toxicities assessed were skin, mucous membrane, lung, esophagus, neurologic, hematologic, and upper GI. QTime was calculated by weighting the time spent with a specific toxicity, as well as local or distant tumor progression. Each toxicity was weighted with increasing severity as the toxicity increased in grade. RESULTS: As expected, patients with the worst KPS (50-70) had the lowest MST (7.8 months) and QTime (6.7 months). Patients <70 years had improved survival with more aggressive therapy (i.e., ICT + SRT or CCT + HRT), while patients > 70 years achieved the best QTime with standard RT (SRT) alone. In patients with squamous cell carcinoma, those treated with ICT + CCT + SRT had dramatically improved MST (25.7 months) and QTime (21.8 months) compared to the other treatment regimens (11.7-12.8 and 10.7-12 months, respectively). Patients with adenocarcinoma, however, generally manifested incrementally better MST and QTime as the therapies intensified. Within the concurrent chemoradiation arms, the upper GI and lung toxicities had the greatest impact on QTime. CONCLUSION: This quality-adjusted survival analysis suggests that there is a critical relationship between the type of histology and its optimal treatment, age and the ability to tolerate intensive therapy, and the need to reduce lung and upper GI toxicities.
Adenocarcinoma↗
Transient exposure to HIV-1 Tat protein results in cytokine production in macrophages and astrocytes. A hit and run phenomenon.
The pathological correlates of dementia due to human immunodeficiency virus (HIV) infection are glial cell activation and cytokine dysregulation. These findings occur in the setting of small numbers of productively infected cells within the brain. We determined whether exposure of susceptible cells to Tat protein of HIV could result in the production of select proinflammatory cytokines. In a dose-responsive manner, Tat induced interleukin (IL)-1beta production in monocytic cells, while astrocytic cells showed an increase in mRNA for IL-1beta, but had a translation block for IL-1beta protein production. Conversely, IL-6 protein and mRNA productions were strongly induced in astrocytic cells and minimally in monocytic cells. IL-1beta and IL-6 production were independent of tumor necrosis factor-alpha production. An exposure to Tat for a few minutes was sufficient for sustained releases of cytokines for several hours. This prolonged cytokine production is likely maintained by a positive feed back loop of Tat-induced nuclear factor kappaB activation and cytokine production that is independent of extracellular calcium. Thus a transient exposure may be sufficient to initiate a cascade of events resulting in cerebral dysfunction and a "hit and run" approach may be in effect. Hence cross-sectional measurement of viral load in the brain may not be a useful indicator of the role of viral products in the neuropathogenesis of HIV dementia.
Astrocytes↗
Interfraction interval does not affect survival of patients with non-small cell lung cancer treated with chemotherapy and/or hyperfractionated radiotherapy: a multivariate analysis of 1076 RTOG patients.
PURPOSE: It was observed by Jeremic et al. that a shorter interfraction interval (IFI) was associated with an improved survival in patients (pts) with locally advanced non-small cell lung cancer (NSCLC) treated with hyperfractionated radiation therapy (HFX-RT), with or without chemotherapy (CT). Our analysis was undertaken to verify this hypothesis. METHODS AND MATERIALS: Records of patients treated on 5 Radiation Therapy Oncology Group (RTOG) studies were reviewed, and an actual IFI, defined as a mean of all daily IFIs, was calculated. RT dose was 1.2 Gy BID to 69.6 Gy. The relationship between the length of IFI and the median survival time and incidence of esophagitis was investigated. RESULTS: In 682 pts eligible for this analysis, a full dose of RT was delivered and at least 90% of all daily IFIs were available. The actual mean IFI was as follows: 4-4.9 h in 51% of pts; 5-5.9 h in 17%; 6-6.9 h in 28% and 7-8 h in 4%. In multivariate analysis, only lack of weight loss, use of CT, low nodal stage and good KPS, but not IFI (4-6 h vs. 6-8 h) were associated with an improved survival for all pts (p values: <0.0001; <0.0001; 0.006; 0.006, and 0.73, respectively), as well as for HFX-RT only pts. For the CT-HFX-RT pts, not enough data points are available for a meaningful analysis. Length of IFI did not influence the incidence of Grade 3 or higher esophagitis (p = 0.82), but use of CT was associated with a 12-fold greater risk of developing severe esophagitis (p < 0.0001). CONCLUSION: Length of IFI (4-6 h vs. 6-8 h) did not influence survival and acute complications incidence in pts with NSCLC treated in RTOG studies with HFX-RT to 69.6 Gy. Previously identified factors, such as use of CT, minimal weight loss, good KPS and low nodal stage, were confirmed again to be associated with a favorable prognosis in a multivariate analysis. Use of CT was associated with a 12-fold greater risk of developing severe esophagitis than HFX-RT alone. It appears that an IFI of 4-8 hr is acceptable in clinical practice for pts with NSCLC, treated with HFX-RT.
Adenocarcinoma↗
Respiratory virus surveillance. FluWatch project.
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Canada↗
Respiratory virus surveillance. FluWatch Project.
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Canada↗
Prevention of exercise-induced bronchospasm in pediatric asthma patients: a comparison of salmeterol powder with albuterol.
BACKGROUND: Exercise-induced bronchospasm (EIB) is a common problem in children with asthma. Pretreatment with the beta2 (beta 2)-adrenoreceptor agonist albuterol is effective for preventing EIB, but is recognized as providing only short-term (2 to 3 hour) protection. OBJECTIVE: To evaluate the 12-hour efficacy and safety of single doses of 25 micrograms and 50 micrograms of salmeterol powder administered via Diskus inhaler versus albuterol aerosol via pressurized metered-dose inhaler and placebo in preventing EIB in asthmatic children. METHODS: A randomized, double-blind, placebo-controlled, double-dummy, single-dose, four-way crossover study was conducted in pediatric patients (4 to 11 years of age) demonstrating EIB and mild-to-moderate asthma. Serial forced expiratory volume in 1 second (FEV1) was measured before and after standard treadmill exercise at hour 1, hour 6, and hour 12 after administration of 25 micrograms or 50 micrograms salmeterol powder, 180 micrograms albuterol aerosol, or placebo. Adverse events were recorded. RESULTS: After completion of the hour 1 exercise challenge, mean minimum % predicted FEV1 was significantly higher following albuterol (91.3%) than for placebo (75.3%) and for both dosages of salmeterol (86.9% and 85.8% for salmeterol 25 micrograms and 50 micrograms, respectively; P < or = .026). After completion of both the hour 6 and hour 12 exercise challenges, the 50-microgram salmeterol treatment produced a significantly higher mean minimum percent of predicted FEV1 (90.6% and 87.3% predicted, respectively) than the mean minimum percent of predicted FEV1 for placebo or albuterol (73.8% to 78.4% of predicted; P < or = .041). At hour 6, the 25-microgram salmeterol treatment was not significantly different from albuterol or placebo. At hour 12, the 25-microgram salmeterol treatment mean minimum percent of predicted was significantly higher than albuterol (87.9% versus 73.8% of predicted; P = .006) and there was also a trend toward significance over placebo (76.9% predicted; P = .056). At all exercise periods, no statistically significant differences in spirometry values were observed between the two salmeterol treatment groups. Safety profiles were similar among treatments, including placebo. No drug-related adverse events or withdrawals due to adverse events occurred. Changes in laboratory values, vital signs, 12-lead ECGs, and physical examinations were unremarkable. CONCLUSIONS: A single 50-microgram dose of salmeterol powder provided effective and safe protection against EIB for at least 12 hours in asthmatic children and provided a significantly more prolonged effect than albuterol aerosol (180 micrograms).
Administration, Inhalation↗
Participation of the melanocortin-1 receptor in the UV control of pigmentation.
The cloning of the melanocortin-1 receptor (MC1R) gene from human melanocytes and the demonstration that these cells respond to the melanocortins alpha-melanocyte stimulating hormone (alpha-MSH) and adrenocorticotropic hormone (ACTH) with increased proliferation and melanogenesis have renewed the interest in investigation the physiological role of these hormones in regulating human pigmentation. Alpha-melanocyte stimulating hormone and ACTH are both synthesized in the human epidermis, and their synthesis is upregulated by exposure to ultraviolet radiation (UVR). Activation of the MC1R by ligand binding results in stimulation of cAMP formation, which is a principal mechanism for inducing melanogenesis. The increase in cAMP is required for the pigmentary response of human melanocytes to UVR, and for allowing them to overcome the UVR-induced G1 arrest. Treatment of human melanocytes with alpha-MSH increases eumelanin synthesis, an effect that is expected to enhance photoprotection of the skin. Population studies have revealed more than 20 allelic variants of the MC1R gene. Some of these variants are overexpressed in individuals with skin type I or II, red hair, and poor tanning ability. Future studies will aim at further exploration of the role of these variants in MC1R function, and in determining constitutive human pigmentation, the response to sun exposure, and possibly the susceptibility to skin cancer.
Alleles↗
Two operons that encode FNR-like proteins in Lactococcus lactis.
Global regulatory circuits of the type mediated by CRP and FNR in Escherichia coli were sought in Lactococcus lactis to provide a basis for redirecting carbon metabolism to specific fermentation products. Using a polymerase chain reaction (PCR) approach, two genes (flpA and flpB) encoding FNR-like proteins (FlpA and FlpB) with the potential for mediating a dithiol-disulphide-dependent regulatory switch, were identified. Transcript analysis indicated that they are distal genes of two paralogous operons, orfX-orfY-flp, in which the orfX and orfY genes were predicted to encode binding domain components of cation ATPases and storage proteins respectively. The corresponding promoters were each associated with a potential FNR site (TTGAT----ATCAA) at positions +4.5 (flpA operon) and -42.5 (flpB operon), suggesting that the respective operons might be negatively and positively autoregulated. The incomplete open reading frames (orfWA/B) located upstream of each operon were predicted to encode additional components of paralogous cation ATPases. No phenotypic effects were detected in flpA and flpB single mutants, but the double mutant had a lower intracellular zinc content, an increased sensitivity to hydrogen peroxide and an altered polypeptide profile (as determined by two-dimensional gel electrophoresis): formate production was not affected. It was concluded tentatively that FlpA and FlpB regulate overlapping modulons, including systems concerned with zinc uptake, in response to metal ion or oxidative stress.
Amino Acid Sequence↗
Involvement of substance P in the anti-inflammatory effects of the peripherally selective kappa-opioid asimadoline and the NK1 antagonist GR205171.
We have previously shown that kappa-opioids have antiarthritic properties. In this study, using two differently acting drugs (the peripherally selective kappa-agonist, asimadoline, and the NK1-antagonist, GR205171), we have examined possible roles of the neuropeptide substance P (SP) in the pathogenesis and maintenance of experimental arthritis in rats. The anti-inflammatory actions and the time dependence of these drugs were compared, and concentrations of SP determined in joint tissue. In untreated animals, SP levels in ankle joint tissue increased late in the disease (by day 21) but substantially lagged behind development of clinical disease. Prolonged (days 1-21 or days 12-18) but not early, short-term (days 1-3) treatment with the NK1-antagonist GR205171 (1 mg/kg/day i.p.) significantly attenuated joint damage; SP levels showed multiphasic dose dependence over the 21-day treatment. The data suggest that GR205171 antagonizes the action of SP by presynaptic as well as postsynaptic mechanisms. Treatment with asimadoline (5 mg/kg/day i.p. ) produced marked (and sustained) attenuation of the disease with all three time regimes. The effect of asimadoline on SP levels was time dependent: reduction of SP content after 3 days but an increase after 12 or 21 days treatment, paradoxically with clinical improvement in each case. Drug-induced changes in SP content could follow from changed release or synthesis from either neural or immune cells. The results suggest that both drugs have potential therapeutic value at different stages of inflammatory joint disease.
Acetamides↗
Genetic and morphological characterization of Cladobotryum species causing cobweb disease of mushrooms.
Cladobotryum dendroides (= Dactylium dendroides) has hitherto been regarded as the major causal agent of cobweb disease of the cultivated mushroom, Agaricus bisporus. Nucleotide sequence data for the internal transcribed spacer (ITS) regions of four Cladobotryum/Hypomyces species reported to be associated with cobweb disease, however, indicate that the most common pathogen is now C. mycophilum. This cobweb pathogen varies somewhat in conidial septation from published descriptions of C. mycophilum and lacks the distinctive colony odor. ITS sequencing revealed minor nucleotide variation which split isolates of the pathogen into three subgroups, two comprising isolates that were sensitive to methylbenzimidazole carbamate (MBC) fungicides and one comprising MBC-resistant isolates. The MBC-resistant isolates, which were only obtained from Ireland and Great Britain, clustered together strongly in randomly amplified polymorphic DNA (RAPD) PCR analysis, suggesting that they may be clonal. The MBC-sensitive isolates were more diverse. A RAPD fragment of 800 to 900 bp, containing a microsatellite and found in the MBC-resistant isolates, also indicated their clonal nature; the microsatellites of these isolates contained the same number of GA repeats. Smaller, polymorphic microsatellites, similarly comprising GA repeats, in the MBC-sensitive isolates in general correlated with their geographic origin.
Agaricus↗
Everting suture correction of lower lid involutional entropion.
AIMS: To assess the long term efficacy of everting sutures in the correction of lower lid involutional entropion and to quantify the effect upon lower lid retractor function. METHODS: A prospective single armed clinical trial of 62 eyelids in 57 patients undergoing everting suture correction of involutional entropion. Patients were assessed preoperatively and at 6, 12, 24, and 48 months postoperatively. The main outcome variables were lower lid position and the change in lower lid retractor function. RESULTS: When compared with the non-entropic side, the entropic lid had a greater degree of horizontal laxity and poorer lower lid retractor function. These differences however, were not significant. At the conclusion of the study and after a mean follow up period of 31 months, the entropion had recurred in 15% of the patients. There were no treatment failures in the group of five patients with recurrent entropion. The improvement in lower lid retractor function after the insertion of lower lid everting sutures did not reach statistical significance. There was no significant difference between the treatment failure group and the group with a successful outcome with regard to: the degree of horizontal lid laxity or lower lid retractor function present preoperatively; patient age or sex; an earlier history of surgery for entropion. There was neither a demonstrable learning effect nor a significant intersurgeon difference in outcome. The overall 4 year mortality rate was 30%. CONCLUSIONS: The use of everting sutures in the correction of primary or recurrent lower lid involutional entropion is a simple, successful, long lasting, and cost effective procedure.
Aged↗
Procarbazine, lomustine, and vincristine (PCV) chemotherapy for anaplastic astrocytoma: A retrospective review of radiation therapy oncology group protocols comparing survival with carmustine or PCV adjuvant chemotherapy.
PURPOSE: To determine any differences in outcome for patients with anaplastic astrocytoma (AA) treated with adjuvant carmustine (BCNU) versus procarbazine, lomustine, and vincristine (PCV) chemotherapy. MATERIALS AND METHODS: The Radiation Therapy Oncology Group (RTOG) database was reviewed for patients with newly diagnosed AA treated according to protocols that included either BCNU or PCV adjuvant chemotherapy. All patients were treated with radiation therapy. The outcome analysis included overall survival, taking into account patient age, extent of resection, Karnofsky performance status (KPS), and treatment group (BCNU v PCV). Stratified and nonstratified Cox proportional hazards models were used, as well as an analysis using matched cases between the groups. RESULTS: A total of 257 patients were treated with BCNU according to RTOG protocols 70-18, 83-02, and 90-06; 175 patients were treated with PCV according to RTOG protocol 94-04. All pretreatment characteristics except KPS were well balanced by treatment group; 61% of the BCNU group had a KPS of 90 to 100 compared with 73% of the PCV group (P =.0075). No statistically significant difference in survival was observed in any age group or by KPS or extent of surgery. The stratified analysis also showed no trends for improved survival by treatment group (P =. 40). The Cox model identified only age, KPS, and extent of surgery as important variables influencing survival, not treatment group. Matching cases between groups using age, KPS, and surgery resulted in 133 matched pairs. No difference in survival was observed (P =. 41). In a Cox model in which each matched pair is a strata, there was no difference between groups (P =.20). CONCLUSION: Using this retrospective analysis, there does not seem to be any survival benefit to PCV chemotherapy. Future phase III studies for patients with AA may need to consider whether BCNU or PCV is used in the control arm.
Adult↗
Prevention of exercise-induced bronchospasm in pediatric asthma patients: A comparison of two salmeterol powder delivery devices.
BACKGROUND: A powder formulation of salmeterol has been shown to prevent exercise-induced bronchospasm (EIB) in asthmatic children and adults; however, the delivery device (Diskhaler; Glaxo Wellcome Inc, Research Triangle Park, NC) must be reloaded after 4 doses. A new multidose powder inhaler (Diskus) provides 60 doses of salmeterol in a blister pack presentation with a dose counter. OBJECTIVE: To evaluate the safety and efficacy of 50-microg salmeterol powder via two different delivery systems (Diskhaler and Diskus) in preventing EIB in asthmatic children. STUDY DESIGN: A randomized, double-blind, double-dummy, single-dose, placebo-controlled, three-way crossover study was conducted in 24 children 4 to 11 years of age demonstrating EIB and mild to moderate asthma. Serial forced expiratory volume in 1 second (FEV(1)) was measured before and after treadmill exercise challenges conducted at 1, 6, and 12 hours after study drug administration. Adverse events were also assessed. RESULTS: During all exercise challenges, EIB-mediated reductions in FEV(1) were minimized or prevented in patients receiving single doses of salmeterol powder compared with placebo. Single doses of salmeterol powder delivered via either system were equally effective in preventing EIB. There were no drug-related adverse events, cardiovascular, or other clinically relevant safety concerns. CONCLUSIONS: Single doses of salmeterol powder delivered by either delivery system are safe and effective in preventing EIB for >/=12 hours in asthmatic children.
Administration, Inhalation↗
Quality of death rates by race and Hispanic origin: a summary of current research, 1999.
OBJECTIVES: This report provides a summary of current knowledge and research on the quality and reliability of death rates by race and Hispanic origin in official mortality statistics of the United States produced by the National Center for Health Statistics (NCHS). It also provides a quantitative assessment of bias in death rates by race and Hispanic origin. It identifies areas for targeted research. METHODS: Death rates are based on information on deaths (numerators of the rates) from death certificates filed in the states and compiled into a national database by NCHS, and on population data (denominators) from the Census Bureau. Selected studies of race/Hispanic-origin misclassification and under coverage are summarized on deaths and population. Estimates are made of the separate and the joint bias on death rates by race and Hispanic origin from the two sources. Simplifying assumptions are made about the stability of the biases over time and among age groups. Original results are presented using an expanded and updated database from the National Longitudinal Mortality Study. RESULTS: While biases in the numerator and denominator tend to offset each other somewhat, death rates for all groups show net effects of race misclassification and under coverage. For the white population and the black population, published death rates are overstated in official publications by an estimated 1.0 percent and 5.0 percent, respectively, resulting principally from undercounts of these population groups in the census. Death rates for the other minority groups are understated in official publications approximately as follows: American Indians, 21 percent; Asian or Pacific Islanders, 11 percent; and Hispanics, 2 percent. These estimates do not take into account differential misreporting of age among the race/ethnic groups.
Adolescent↗
Nutritional guidance for the ESRD patient in long-term care facilities.
The health care teams dealing with the long-term care resident with ESRD need to develop and implement ethical, humanistic and practical guidelines which enhance the continuity of comprehensive medical, psychosocial, and nutrition care. Increased quality of life, heightened satisfaction, improved nutritional status, and decreased feelings of isolation are important potential benefits to these patients.
Guidelines as Topic↗