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Results for “Multivariate response regression”

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PubMed1993

[A study to predict the clinical efficacy of house dust mite immunotherapy in bronchial asthmatics].

To predict the clinical efficacy of house dust mite immunotherapy (IT), clinical factors before IT were analyzed in relation to clinical efficacy in bronchial asthmatics treated by standard IT method. In 111 asthmatics treated by IT, 88 cases (80%) obtained favorable results over a one-year period, while only 39% of asthmatics without IT showed clinical improvement (p < 0.05, chi 2 test). Factors including severity, skin test threshold, age, age at which IT was started, duration of asthma, onset of asthma, FEV1.0% and serum IgE levels before IT were analyzed. Severity showed the most significant influence on clinical efficacy (r = 0.412, p < 0.01). A study to determine whether some specific criteria could be used to predict the clinical efficacy of IT was then carried out. Using multivariate analysis with the factors above mentioned, the clinical efficacy ranging from deteriorated to good response could be expressed as a formula with a multi-regression coefficient of 0.56, p < 0.05. Moreover, the application of linear discriminating analysis gave an 80% true positive discriminating rate in 75 asthmatics. In both methods, severity seemed to be the most important factor, skin test threshold next and FEV1.0% third. The other factors were not significant. Hopefully, the use of this formula in clinical practice will improve the efficacy of IT, thus providing further therapeutic benefits to bronchial asthmatics.

Adult↗

PubMed2003

Health related quality of life and related factors in 539 persons with amputation of upper and lower limb.

PURPOSE: Limb amputation is followed by an important rehabilitation process, especially when a prosthesis is involved. The objective of this study is to assess the nature of factors related to health related quality of life (HRQL) of persons with limb amputation. METHOD: The Nottingham Health Profile (NHP) treated 1011 subjects with major amputation of one or several limbs. Correlations were sought in multivariate regression model analyses between the six categories of distress explored by the NHP and age, sex, cause and level of amputation and rehabilitation programme. RESULTS: Response rate was 53.3%. HRQL measured by the NHP was mostly impaired in the categories of physical disability, pain and energy level. Controlling for sex and age, young age at the time of amputation, traumatic origin and upper limb amputation were independently associated with better HRQL. CONCLUSION: It is concluded that HRQL is largely related to factors which are inherent to the patient and the amputation.

Age Factors↗

PubMed2006

A haplotype of the methylenetetrahydrofolate reductase gene predicts poor tumor response in rectal cancer patients receiving preoperative chemoradiation.

OBJECTIVE: The objective of the present study was to evaluate whether germline methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms as well as polymorphisms in the thymidylate synthase gene promoter, namely the variable number tandem repeat polymorphism (TS VNTR) and the intrarepeat G to C single nucleotide polymorphism (TS SNP), are predictive markers of tumor regression in rectal cancer patients following preoperative chemoradiotherapy. BASIC METHODS: Blood samples from 125 patients with primary adenocarcinoma of the mid-low rectum who received 5-fluorouracil-based chemotherapy and external beam radiotherapy (median dose 48.4 Gy), 125 patients (women n=45, men n=80; median age 60 years, range 31-79 years) were genotyped. Response to preoperative treatment was evaluated employing the Tumor Regression Grade criteria. On the basis of the pathologic response, patients were classified as responders (TRG 1-2, n=48) and non-responders (TRG 3-5, n=74). Three patients were excluded because of insufficient data. MAIN RESULTS: Among the polymorphic variants examined, the MTHFR 677T-1298A haplotype was, upon univariate analysis, the only variable found associated with tumor regression (P=0.004). Moreover, at multivariate analysis, the MTHFR 677T-1298A haplotype was an independent predictor of tumor regression. Patients not carrying the MTHFR 677T-1298A haplotype (odds ratio 0.29, 95% confidence interval 0.13-0.64, P=0.002) displayed a higher response rate than patients with the MTHFR 677T-1298A haplotype. CONCLUSIONS: Unlike TS VNTR and SNP polymorphisms, MTHFR 677T-1298A haplotype in genomic DNA has the potential to be a predictive marker of tumor response in rectal cancer patients submitted to preoperative chemoradiotherapy.

Adenocarcinoma↗

PubMed1997

Dose-response relationship between prevalence of cerebrovascular disease and ingested inorganic arsenic.

BACKGROUND AND PURPOSE: Circulatory diseases such as ischemic heart disease and peripheral vascular disease induced by long-term arsenic exposure have been well documented in previous studies, but the dose-response relationship between cerebrovascular disease and ingested inorganic arsenic remains to be elucidated. The prevalence of cerebrovascular disease among residents of the Lanyang Basin on the northeast coast of Taiwan was surveyed to examine its association with exposure to arsenic in well water. METHODS: A total of 8102 men and women from 3901 households were recruited in this study. The status of cerebrovascular disease of study subjects was identified through home-visit personal interviews and ascertained by review of hospital medical records according to the World Health Organization criteria. Information on consumption of well water, sociodemographic characteristics, cigarette smoking, and alcohol consumption habits, as well as personal and family history of diseases, was also obtained. Arsenic concentration in the well water of each household was determined by hydride generation and atomic absorption spectrometry. Logistic regression analysis was used to estimate multivariate-adjusted odds ratios and 95% confidence intervals for various risk factors of cerebrovascular disease. RESULTS: A significant dose-response relationship was observed between arsenic concentration in well water and prevalence of cerebrovascular disease after adjustment for age, sex, hypertension, diabetes mellitus, cigarette smoking, and alcohol consumption. The biological gradient was even more prominent for cerebral infarction, showing multivariate-adjusted odds ratios of 1.0, 3.4, 4.5, and 6.9, respectively, for those who consumed well water with an arsenic content of 0, 0.1 to 50.0, 50.1 to 299.9, and > 300 micrograms/L. CONCLUSIONS: Long-term exposure to inorganic arsenic from well water was associated with an increased prevalence of cerebrovascular disease, especially cerebral infarction.

Adult↗

PubMed2005

Relationship between endothelial function in the coronary and brachial arteries.

BACKGROUND: Endothelial dysfunction is the first step in the progression to atherosclerosis, but little is known regarding whether there is a correlation in endothelial function between the coronary and peripheral arteries. HYPOTHESIS: We investigated the relationship between coronary and peripheral endothelial function. METHODS: In 41 patients (mean age 63 years; 23 men, 18 women) with angiographically normal coronary arteries, changes in brachial artery diameter in response to hyperemic flow and sublingual nitroglycerin (NTG) were measured by high-resolution ultrasonography. During coronary angiography, acetylcholine (ACh, 3 and 30 microg/min) and NTG were infused into the left coronary ostium. The diameter of the coronary artery was quantitatively measured and coronary blood flow (CBF) was calculated by quantitative angiography and Doppler flow velocity measurements. Changes in these parameters in response to each drug infusion were expressed as the percent change from the baseline values. RESULTS: Flow-mediated dilation (FMD) of the brachial artery was 5.0 +/- 3.5% and correlated positively not only with the change in coronary diameter (ACh at 30 microg/min, r = 0.31, p < 0.05) but also with the change in CBF (ACh at 3 microg/min, r = 0.39, p < 0.05; ACh at 30 microg/min, r = 0.46, p < 0.01). Multivariate analysis demonstrated that FMD was one of the factors associated with the changes in coronary diameter and CBF. CONCLUSIONS: These results suggest that brachial endothelial function is associated with coronary endothelial function in patients with angiographically normal coronary arteries, suggesting that impairment of endothelial function may occur simultaneously in both coronary and peripheral arteries.

Acetylcholine↗

PubMed2006

T-cell reactivity against HSP60 relates to early but not advanced atherosclerosis.

BACKGROUND: Anti-heat-shock protein 60 (HSP60) antibody-levels have been linked to carotid atherosclerosis and cardiovascular risk in a variety of studies. The potential role of cellular immune reactions against HSP60 has so far attracted little attention in epidemiological research. METHODS AND RESULTS: In vitro T-cell reactivity to various HSP60s and tuberculin was assessed in blood samples from a elderly subpopulation of the Bruneck study (100 men, 50-69 years) and the young participants of the ARMY study (141 men, 17-18 years), and analyzed for a potential association with common carotoid artery intima-media thickness (IMT). In vivo skin reaction against tuberculin was recorded in subjects of the Bruneck study and correlated with the in vitro proliferative response to tuberculin (P=0.004). T-cells isolated from peripheral blood of all individuals proliferated upon stimulation with HSP60s. In multivariate linear regression analysis adjusted for standard risk factors, T-cell stimulation was significantly related to IMT in the ARMY (P=0.005 for human HSP60 and P=0.064 for mycobacterial HSP60) but not in the Bruneck study. CONCLUSIONS: T-cell reactivity against HSP60s correlated with IMT in male youngsters but not in men aged 50 and over, indicating a more prominent role of specific cellular immunity to HSP60s in the young and very early stages of atherosclerosis.

Age Factors↗

PubMed2005

Positron emission tomography-measured abnormal responses of myocardial blood flow to sympathetic stimulation are associated with the risk of developing cardiovascular events.

OBJECTIVES: We sought to assess prospectively whether patients with normal coronary angiograms but with impaired myocardial blood flow (MBF) increases to cold pressor testing (CPT) are at increased risk for cardiovascular events. BACKGROUND: Invasive angiographic assessments of coronary vasomotor function have demonstrated an impairment of endothelium-related coronary flow increases to independently predict future cardiovascular events. It is unknown whether noninvasive positron emission tomography (PET)-measured MBF alterations to sympathetic stimulation with CPT are associated with the risk of developing cardiovascular events. METHODS: A total of 72 patients (44 men, 28 women, age 58 +/- 8 years) referred for diagnostic cardiac catheterization were studied. Myocardial blood flow was measured in absolute units with (13)N-ammonia using PET, at baseline and during CPT in each patient. Cardiovascular events (cardiovascular death, acute coronary syndrome, myocardial infarction, percutaneous transluminal coronary angioplasty, coronary artery bypass grafting, ischemic stroke, or peripheral revascularization) were assessed as clinical outcome parameters over a mean follow-up period of 66 +/- 8 months. Patients were assigned to three groups: group 1, patients with >/=40% increase in MBF (%DeltaMBF), n = 22; group 2, patients with >0 and <40% increases in MBF, n = 32; and group 3, patients with decreases in MBF (</=0%), n = 18. RESULTS: During follow-up, one of the group 1 patients developed a cerebral stroke. In group 2, 15 cardiovascular events occurred in 9 patients and in group 3, 7 patients experienced 9 cardiovascular events (p </= 0.0001, univariate by log-rank test). Impaired MBF increases in group 2 and group 3 were associated with a significantly higher incidence of cardiovascular events by Kaplan-Meier analysis (p = 0.033, log-rank test). After adjusting for known coronary risk factors, MBF responses to CPT revealed a nonsignificant trend to be independently associated with a higher incidence for cardiovascular events (p = 0.065, multivariate by Cox regression model). CONCLUSIONS: Noninvasive PET-measured impaired MBF increases to sympathetic stimulation are associated with the risk of developing cardiovascular events.

Ammonia↗

PubMed2004

Does the association between ill health and unemployment differ between young people and adults? Results from a 14-year follow-up study with a focus on psychological health and smoking.

OBJECTIVES: Research has given a comprehensive picture of the negative health consequences of unemployment without offering sufficient comparison between different age groups. The aim of this study was to analyse whether the associations between ill health, particularly poor psychological health and smoking, and unemployment differ between young and adult men and women. STUDY DESIGN: A 14-year follow-up study of graduates of compulsory school in an industrial town in northern Sweden was undertaken. The subjects were analysed at ages 16, 21 and 30 years. Complete data on the cohort were collected for 1044 individuals with the aid of a comprehensive questionnaire. The response rate was 96.4%. METHODS: The main health measurements used in this study were poor psychological health and smoking, analysed by multivariate logistic regression. RESULTS: After controlling for several background variables, associations between long-term unemployment and poor psychological health were found in young men and women, and adult men. Long-term unemployment was only associated with smoking in young people. CONCLUSIONS: The association between long-term unemployment and psychological health, as well as smoking, seemed to be stronger in young people than adults.

Adolescent↗

PubMed2003

National and regional differences in preparation for future care needs: a comparison of the United States and Germany.

Planning for future care needs is likely to be influenced by both policy and culture. We compared attitudes regarding the usefulness of planning ahead for future care needs, processes of preparation for these needs (becoming aware of the risk of future care needs, gathering information about available options, deciding on preferences, concrete planning), and outcomes of preparation (e.g., knowledge about services) in 294 East German, 288 West German, and 590 American seniors. American respondents had higher preparation scores. Compared to the size of national differences, differences between East and West German seniors were generally smaller. East Germans made fewer decisions on preferences and engaged in less concrete planning. Most of the national and regional differences in preparation for future care needs were reduced or eliminated by controlling for differences in the perceived usefulness of planning.

Aged↗

PubMed2005

Low plasma selenium concentrations, high plasma human immunodeficiency virus load and high interleukin-6 concentrations are risk factors associated with anemia in adults presenting with pulmonary tuberculosis in Zomba district, Malawi.

BACKGROUND: Although anemia is common among adults with pulmonary tuberculosis and human immunodeficiency virus (HIV) infection in sub-Saharan Africa, the factors contributing to its pathogenesis have not been well characterized. OBJECTIVE: To characterize the antioxidant micronutrient status, interleukin-6 (IL-6) concentrations, and HIV load in relationship with anemia in adults with pulmonary tuberculosis. SETTING: Zomba district, Malawi. METHODS: Erythropoietin, IL-6, plasma HIV load, and markers of micronutrient status (hemoglobin (Hb), plasma concentrations of retinol, alpha-tocopherol, carotenoids, ferritin, zinc, and selenium) were measured in 500 adults who presented with pulmonary tuberculosis in Zomba Central Hospital, Malawi. RESULTS: Among 370 HIV-positive and 130 HIV-negative adults, the prevalence of anemia was 88 and 77%, respectively (P = 0.002), and moderate to severe anemia (Hb < 80 g/l) occurred in 30 and 15%, respectively (P = 0.001). Geometric mean IL-6 concentration was 21.1 pg/ml, with no difference between HIV-positive and -negative adults. The erythropoietin response to anemia was not different between adults with elevated IL-6 and those with lower IL-6 concentrations. In a multivariate logistic regression model, HIV load, and lower plasma selenium concentrations were associated with moderate to severe anemia. In a final multivariate linear regression model, IL-6, plasma HIV load, and plasma selenium concentrations were associated with Hb concentrations. CONCLUSION: This study suggests that low selenium concentrations, high HIV load, and high IL-6 concentrations are associated with anemia in adults with pulmonary tuberculosis in sub-Saharan Africa.

Adult↗

PubMed2004

Undulating toe movements in brain death.

For many years, death implied immobility. Nevertheless, there are anecdotal reports of spontaneous or reflex movements (SRMs) in patients with Brain death (BD). The presence of some movements can preclude the diagnosis of BD, and consequently, the possibility of organ donation for transplantation. McNair and Meador [(1992), Mov Dord7: 345-347] described the presence of undulating toe flexion movements (UTF) in BD patients. UTF consists in a sequential brief plantar flexion of the toes. Our aim was to determine the frequency, characteristics and predisposing factors of UTF movements in a prospective multicenter cohort study of patients with BD. Patients with confirmed diagnosis of BD were assessed to evaluate the presence of UTF using a standardized protocol. All patients had a routine laboratory evaluation, CT scan of the head, and EEG. Demographic, clinical, hemodynamic and blood gas concentration factors were analyzed. amongst 107 BD patients who fulfilled the AAN requirements, 47 patients (44%) had abnormal movements. UTF was observed in 25 (23%) being the most common movement (53%). Early evaluation (OR 4.3, CI95% 1.5-11.9) was a predictor of UTF in a multivariate regression model. The somato-sensory evoked potential (SSEPs) as well as brainstem auditory evoked potentials (BAEPs) did not elicit a cortical response in studied patients with UTF. This spinal reflex is probably integrated in the L5 and S1 segments of the spinal cord. Abnormal movements are common in BD, being present in more than 40% of individuals. UTF was the most common spinal reflex. In our sample, early evaluation was a predictor of UTF. Health care professionals, especially those involved in organ procurement for transplantation, must be aware of this sign. The presence of this motor phenomenon does not preclude the diagnosis of BD.

Adult↗

PubMed2005

Virological and pharmacological parameters predicting the response to lopinavir-ritonavir in heavily protease inhibitor-experienced patients.

The genotypic inhibitory quotient (GIQ) has been proposed as a way to integrate drug exposure and genotypic resistance to protease inhibitors and can be useful to enhance the predictivity of virologic response for boosted protease inhibitors. The aim of this study was to evaluate the predictivity of the GIQ in 116 protease inhibitor-experienced patients treated with lopinavir-ritonavir. The overall decrease in human immunodeficiency virus type 1 (HIV-1) RNA from baseline to month 6 was a median of -1.50 log(10) copies/ml and 40% of patients had plasma HIV-1 RNA below 400 copies/ml at month 6. The overall median lopinavir study-state C(min) concentration was 5,856 ng/ml. Using univariate linear regression analyses, both lopinavir GIQ and the number of baseline lopinavir mutations were highly associated with virologic response through 6 months. In the multivariate analysis, only lopinavir GIQ, baseline HIV RNA, and the number of prior protease inhibitors were significantly associated with response. When the analysis was limited to patients with more highly mutant viruses (three or more lopinavir mutations), only lopinavir GIQ remained significantly associated with virologic response. This study suggests that GIQ could be a better predictor of the virologic response than virological (genotype) or pharmacological (minimal plasma concentration) approaches used separately, especially among patients with at least three protease inhibitor resistance mutations. Therapeutic drug monitoring for patients treated by lopinavir-ritonavir would likely be most useful in patients with substantially resistant viruses.

Adult↗

PubMed2006

Dermatologists' views and opinions about photo(chemo)therapy and conventional systemic psoriasis therapies: results from a Belgian survey.

BACKGROUND: Experts' opinions about old and new psoriasis therapies are well documented. OBJECTIVES: To document the views and opinions of a large, diverse group of dermatologists about psoriasis treatment. PARTICIPANTS/METHODS: A survey was conducted among Belgian dermatologists. In addition to demographic and professional characteristics, the questionnaire assessed the self-rated level of experience, frequency of use, preference and considerations regarding UVB, PUVA, methotrexate (MTX), cyclosporin (CsA) and acitretin. Multivariate logistic regression analyses were performed to investigate predictors of these dermatologist-based outcomes. RESULTS: Of the 628 contacted dermatologists, 310 responded (response rate of 49.3%). The dermatologists were significantly more experienced with photo(chemo)therapy than with systemic agents (p < or = 0.02); about half reported none or little experience with MTX and CsA. Also, photo(chemo)therapies were significantly more frequently used than systemic drugs (p < or = 0.01). In the last year, almost 40% had not used and less than 10% had used MTX or CsA more than 10 times. Despite the limitations of PUVA, it was preferred to UVB, followed by acitretin (+/- phototherapy), and MTX and CsA were considered final options by most dermatologists. After adjusting for confounding variables, age, years in practice, seeing and treating more patients, residency programme and/or access to UV therapy were significantly associated with limited experience, regular use and/or preference of studied therapies. CONCLUSION: Either a substantial proportion of the dermatologists does not need or wish to use conventional systemic psoriasis therapies or they may need better and more uniform training during and after their residency. This may improve patient care and patient selection for other treatments.

Adult↗

PubMed2003

C-reactive protein, antiinflammatory drugs, and quality of life in diabetes.

BACKGROUND: C-reactive protein (CRP) is an important biological marker of inflammation that has been linked to cardiovascular disease. The extent to which the inflammatory processes associated with elevated CRP concentrations impair physical functioning and quality of life, and whether this is modulated by hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) and aspirin, which have been shown to lower CRP concentrations, is unclear. OBJECTIVE: To determine whether an association exists between CRP concentrations and health-related quality of life among patients with diabetes, and to determine whether the association is affected by use of statins and nonsteroidal antiinflammatory drugs (NSAIDs). METHODS: A trained interviewer collected self-reported information regarding demographics, health-related quality of life (SF-12), and medication use, and a nurse collected a blood sample from 86 adult subjects with type 2 diabetes mellitus who were part of a larger population-based survey. The serum was analyzed for CRP using a highly sensitive assay. RESULTS: In simple bivariate analysis, there was a significant inverse relationship between CRP and the physical health component score of health-related quality of life (Spearman correlation coefficient [r] = -0.26; p = 0.025). For subjects on statins (r = -0.44; p = 0.02; n = 27), this relationship persisted, while for patients on NSAIDs or aspirin (r = -0.21; p = 0.17; n = 44), no relationship was observed. Similar findings were observed with self-rated health alone as an outcome variable. However, stepwise linear regression revealed no consistent relationship between CRP and health-related quality of life (i.e., standardized SF-12 physical component score) when demographic variables, disease duration, glucose control, serum creatinine, smoking, and medication use were controlled for. CONCLUSIONS: In multivariate regression modeling, the initial inverse relationship between CRP and health-related quality of life was lost, suggesting that other covariates are responsible for this association. While statins and NSAIDs may impact CRP or health-related quality of life independently, they do not appear to modulate a relationship between these factors.

Analysis of Variance↗

PubMed2001

Increased glucose-dependent insulinotropic polypeptide (GIP) secretion in acromegaly.

OBJECTIVE: Acromegaly is often associated with fasting and postprandial hyperinsulinemia, and the mechanisms involved are only partly understood. Hypersecretion of incretins such as glucose-dependent insulinotropic polypeptide (GIP) could play a role in determining hyperinsulinemia in acromegaly, but the available data are inconsistent. The aim of this study was to characterize the fasting and postprandial pattern of plasma GIP and insulin in a group of acromegalic patients. DESIGN AND METHODS: Eleven non-diabetic patients with newly diagnosed acromegaly and 11 sex- and age-matched healthy subjects were studied. Blood samples were taken at regular intervals in fasting conditions and for 3 h after a standard solid-liquid meal for growth hormone (GH), GIP and insulin measurements. RESULTS: Not only insulin, but also fasting and postprandial GIP levels were significantly higher in the patients with acromegaly than the healthy subjects (P<0.01). In the former group fasting GIP levels and the integrated GIP response to the meal correlated significantly with GH basal levels (r=0.83, P<0.01 and r=0.65, P<0.05, respectively). Moreover, multivariate linear regression analysis showed that the presence of acromegalic status was associated with higher fasting and postprandial GIP levels independently of sex, age, fasting and postprandial plasma glucose and insulin levels, and the occurrence of normal or impaired glucose tolerance. CONCLUSION: This study provides evidence that in patients with acromegaly fasting and postprandial GIP levels are abnormally high. GIP hypersecretion in turn might play a role in the pathogenesis of hyperinsulinemia that characterizes acromegaly.

Acromegaly↗

PubMed1999

Nursing facilities and managed care.

OBJECTIVE: To examine the extent to which Illinois nursing facilities have developed relationships with other healthcare providers, particularly managed care organizations (MCOs). STUDY DESIGN: A cross-sectional survey of nursing facilities designed to determine: 1) relationship objectives; 2) obstacles to developing relationships; 3) currently available services; 4) staffing for these services and; 5) nursing facility approaches to networking. The survey was sent to a census sample of 867 nursing facilities serving the elderly in Illinois. Descriptive and multivariate logistic regression analyses of relationships determined to be formal/risk-sharing were performed. STUDY POPULATION: The sample included 523 Illinois nursing facilities. A total response rate of 60% was achieved (523/867). RESULTS: Higher strategic goals, urban location, nonprofit ownership status, higher percentages of private pay and/or Medicare clients (vs Medicaid), and provision of home care and subacute services were all significant predictors of formal or risk-sharing relationships with MCOs. CONCLUSIONS: Facilities with more relationships and higher goals have more formal/risk-sharing relationships with MCOs. Facilities in urban areas have more relationships, likely due to the fact that rural facilities have fewer options and operate in different markets. In addition, nursing facilities rely on Medicare referrals from hospitals, and these Medicare patients, especially those in urban areas, are increasingly controlled by MCOs.

Aged↗

PubMed2004

Comparison of the hemolytic activity of isopropoxyethanol and phenoxyethanol.

OBJECTIVES: Administration of ethylene glycol monoalkyl ethers to rodents causes acute hemolytic anemia. Metabolic activation of these chemicals to alkoxyacetic acids is required to develop hemolytic effect. Current study was undertaken to compare the hemolytic activity of isopropoxyethanol (IPE) and phenoxyethanol (PhE) in male rats. The main goal of this study was to evaluate the role of alkyl and aryl group in hemolytic activity of ethylene glycol ethers. MATERIALS AND METHODS: Rats were treated subcutaneously with single doses of 0, 0.625, 1.25 and 2.5 mmol IPE/kg body weight or 0, 2.5, 5.0 and 10.0 mmol PhE/kg. At 0, 6, 24, 48, 144, 216, and 600 h after dosing, blood samples were collected from end tail of rats and various blood indices were measured. RESULTS: Administration of both chemicals resulted in a time- and dose-dependent swelling of erythrocytes as evidenced by an early increase in packed cell volumes and mean cell volume. Subsequently, red blood cells, total hemoglobin concentration, and packed cell volumes decreased when hemolysis progressed. Furthermore, an increase in plasma hemoglobin concentration and reticulocyte counts was observed. The onset of hemolysis induced by IPE was faster than that after PhE administration. The hemolytic activity of IPE was about tenfold higher in comparison with PhE. CONCLUSIONS: It is likely that the lower hemolytic activity of PhE is associated with inhibitory effect of aryl group on hemolytic action of this compound. Phenyl group, in contrast with alkyl moiety, represents electron acceptor system which exerts resonance and inductive effects and leads to changes in acid strength, also in case of phenoxyacetic acid, a metabolite of PhE.

Anemia, Hemolytic↗

PubMed2000

Association models for a multivariate binary response.

Models for a multivariate binary response are parameterized by univariate marginal probabilities and dependence ratios of all orders. The w-order dependence ratio is the joint success probability of w binary responses divided by the joint success probability assuming independence. This parameterization supports likelihood-based inference for both regression parameters, relating marginal probabilities to explanatory variables, and association model parameters, relating dependence ratios to simple and meaningful mechanisms. Five types of association models are proposed, where responses are (1) independent given a necessary factor for the possibility of a success, (2) independent given a latent binary factor, (3) independent given a latent beta distributed variable, (4) follow a Markov chain, and (5) follow one of two first-order Markov chains depending on the realization of a binary latent factor. These models are illustrated by reanalyzing three data sets, foremost a set of binary time series on auranofin therapy against arthritis. Likelihood-based approaches are contrasted with approaches based on generalized estimating equations. Association models specified by dependence ratios are contrasted with other models for a multivariate binary response that are specified by odds ratios or correlation coefficients.

Antirheumatic Agents↗