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Biomedical subjects

R Kessler

Publications and source records attributed to R Kessler.

225 records · Page 13Linked to original sources
PubMedDate not supplied

Regulation of endothelin-1 at rest and during a short steady-state exercise in 21 COPD patients.

Endothelin-1 (ET-1) is a vasoconstrictive peptide which may play a relevant role in the pathogenesis of pulmonary hypertension (PH) in COPD patients. We assessed the correlations of plasmatic ET-1 levels with pulmonary function data, arterial blood gases and pulmonary haemodynamics in 21 COPD patients with moderate to severe airway obstruction (FEV1: 1.19+/-0.49 l, mean+/-SD). There were 11 hypoxemic patients (PaO2 <65 mmHg). Six patients had resting PH (mean pulmonary artery pressure >/=20 mmHg). Eight patients had exercising PH (PAP >/=30 mmHg) during a short (6 min) 30 W steady state exercise. At rest, arterial ET-1 levels were significantly higher in COPD patients with hypoxemia when compared to those without hypoxemia (16.6+/-2.7 vs. 12.5+/-3.9 pM/l, P=0.02) and in COPD patients with PH when compared to those without PH (16.5+/-3.4 vs. 13+/-3.9 pM/l, P=0.04). Resting arterial ET-1 levels were negatively correlated with PaO2 (r=-0.45, P=0.05). At rest, the differences between mixed venous and arterial ET-1 levels were positively correlated with FEV1 (r=0.54, P=0.024). At exercise, the mean arterial ET-1 level was not significantly different from the mean resting ET-1 level (13.8+/-3.4 vs. 13.3+/-4 p M/l, NS). There were eight COPD patients who had decreasing arterial ET-1 levels between rest and the end of a 6 min exercise, and six COPD patients who had increasing arterial ET-1 levels. These variations of arterial systemic ET-1 levels from rest to exercise were negatively correlated with FEV1 (r=-0.66, P=0.01). We conclude that in COPD patients (1) at rest, arterial ET-1 levels are increased in hypoxemia or pulmonary hypertension and (2) at rest or during exercise, the turn-over of ET-1 may be dependent of the degree of the bronchial obstruction.

Aged↗
PubMedDate not supplied

Frontal cortex and basal ganglia metabolic rates assessed by positron emission tomography with [18F]2-deoxyglucose in affective illness.

Twenty affective disorder patients (16 bipolar and 4 unipolar) and 24 normal controls received scans with positron emission tomography (PET) using [18F]2-deoxyglucose (FDG) as a tracer. Subjects received a series of brief electrical stimuli to their right arms during FDG uptake. Patients with bipolar affective illness had significantly lower frontal to occipital glucose metabolic rate ratios (relative hypofrontality) and significantly lower metabolic rates in their basal ganglia in comparison to whole slice metabolism than normal controls. Patients with unipolar illness showed significantly higher frontal to occipital ratios, and also showed relatively decreased metabolism in the basal ganglia. All results in unipolar patients should be considered exploratory due to the small number of patients. Clinical depression ratings correlated negatively with whole slice metabolic rate.

Adult↗
PubMedDate not supplied

Sildenafil (Viagra) and ophthalmology.

Sildenafil citrate (Viagra) is a new oral medication that inhibits phosphodiesterase-5 (PDE5) in the corpus cavernosum to facilitate penile erection for the treatment of male impotence. The drug also has a mild inhibitory effect on PDE6, which controls the level of cyclic guanosine monophosphate in the retina, and it may cause a perception of bluish haze or increased light sensitivity in some patients. Long-term retinal damage has not been reported, but long-term electroretinographic studies have not been performed. Sildenafil causes a mild lowering of blood pressure and is absolutely contraindicated in patients taking any form of nitrate medication. A number of cardiovascular deaths and retinal vascular events in patients taking sildenafil have been reported, but so far the rate of these complications does not exceed expectation for an elderly population. Ophthalmologists should alert patients to the ocular side effects and potential risks of this new drug until further clinical experience has been obtained.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMedDate not supplied

Role of poloxamer 188 during recovery from ischemic spinal cord injury: a preliminary study.

Paraplegia following aortic surgery is not a common event. When it does occur it significantly alters the patient's outcome. Poloxamer 188 (P188) has been shown in the experimental animal to increase regional blood flow to ischemic areas. In order to investigate its protective effect during aortic cross-clamping, 23 animals were randomized to two groups (placebo n = 11, P188n = 12) and received an intravenous injection of placebo or P188 (200 mg/kg), and underwent occlusion of the thoracic aorta and both subclavian arteries for a period of 13 minutes. They were then connected to an intravenous pump delivering either placebo or P188 (250 mg/kg/hr at a rate of 0.942 ml/hour) for 48 hours. Hindlimb function was appraised, daily for 30 days, by a lesion score (0-15). Spinal cord injury was assessed by a histologic score (0-3) based on the degree of gray and white matter gliosis, number of motor neurons, and white matter myelination. Analysis of variance for repeated measures did not reveal significant difference between P188 and placebo groups (P = 0.66). Similarly, the mean histologic scores (placebo = 1.54 +/- 0.41 SE, P188 = 1.08 +/- 0.33 SE) did not differ (Wilcoxon, P = 0.43). We conclude that intravenous administration of P188 before, during, and for 48 hours after aortic cross-clamping does not prevent paraplegia or improve the long term neurologic outcome.

Animals↗
PubMedDate not supplied

Psychosocial factors associated with fruit and vegetable consumption.

PURPOSE: This study examined the relationship between various psychosocial factors and fruit and vegetable consumption. DESIGN: The 5 A Day Baseline Survey, conducted in August 1991, just before the initiation of the 5 A Day for Better Health Program, obtained data on adults' intakes of, and their knowledge, perceptions, and attitudes regarding, fruits and vegetables. SETTING: The survey was conducted by telephone. SUBJECTS: Subjects were 2811 adults (response rate, 43%) aged 18 years and older in the 48 coterminous United States. MEASURES: Fruit and vegetable intake was measured as self-reported frequency of use; most of the psychosocial variables were measured using Likert scales. RESULTS: This study estimates that only 8% of American adults thought that five or more servings of fruits and vegetables were needed for good health. Of the factors studied, the most important in determining someone's fruit and vegetable intake were the number of servings they thought they should have in a day, whether they liked the taste, and whether they had been in the habit of eating many fruits and vegetables since childhood. These few factors accounted for 15% more of the variation in fruit and vegetable consumption than did demographic variables alone (8%). CONCLUSIONS: Nutrition education should stress the need to eat five or more servings of fruits and vegetables per day because few adults are aware of this recommendation and such knowledge is strongly associated with increased intake. Furthermore, efforts to increase the palatability of fruits and vegetables, especially among children, should be promoted.

Adolescent↗
PubMedDate not supplied

Fruit and vegetable intake in the United States: the baseline survey of the Five A Day for Better Health Program.

PURPOSE: The purpose of the Five A Day Baseline Survey was to assess fruit and vegetable intake and associated factors among US adults. DESIGN: Questionnaires querying frequency of intake of 33 fruits and vegetables, as well as demographics, attitudes, and knowledge related to fruits and vegetables were administered by telephone. SETTING: The study was a nationally representative random digit dial survey conducted by telephone in the summer of 1991; response rate was 42.8%. SUBJECTS: Respondents were 2811 US adults (including an oversample of African-Americans and Hispanics). MEASURES: Mean and median self-reported intakes of fruits and vegetables were calculated. Estimated servings per week were adjusted on the basis of responses to summary questions regarding overall fruit and vegetable intakes. RESULTS: Median intake of fruits and vegetables was 3.4 servings per day. Linear regressions (accounting for no more than 10% of the variation) showed that education, income, and smoking status were predictors of fruit and vegetable intake and that intake increased with education, income, and nonsmoking status. Women had higher intakes than men at all ages; these differences between men and women increased with age. Fruit and vegetable intakes increased with age for whites and Hispanics, but not for African-Americans. CONCLUSIONS: Fruit and vegetable intake among adults in the United States is lower than the recommended minimum of five daily servings. These data will be useful in targeting campaign efforts and in assessing progress of the Five A Day for Better Health Program.

Adult↗
PubMedDate not supplied

[Epidemiology of mental disorders in Spain: methods and participation in the ESEMeD-Spain project].

INTRODUCTION: The ESEMeD-Spain study is part of a European project on the epidemiology of mental disorders, which is also part of a World Health Organization initiative called World Mental Health Surveys. The main objectives of the study are to estimate the prevalence of mental disorders in Spain; to analyze their association with sociodemographic variables and predisposing and protective factors; to evaluate their impact on the quality of life; and to describe and evaluate the health care received by people with mental disorders. METHODS: A representative sample of the noninstitutionalized Spanish population older than 18 years is interviewed. Sample size is 5,500 people. The instrument used in the interviews is the Composite International Diagnostic Interview (CIDI), a questionnaire designed to be used by lay interviewers that allows the diagnosis of psychiatric disorders. Strict quality control of field work has been established. Furthermore, approximately 200 subjects are re-interviewed by a psychiatrist using the Structured Clinical Interview for DSM-IV (SCID) and several questionnaires to measure clinical severity. RESULTS: Field work started in September 2001 and finished in November 2002. Up to Ap ril 2002, more than 4,300 people have been interviewed. Preliminary response rate has been 68.7%. Comparison of the age and gender of the study sample with the general Spanish population shows high representativeness. CONCLUSIONS: The ESEMeD-Spain project will produce un - precedented scientific information about the epidemiology of mental disorders in Spain.

Adult↗
PubMedDate not supplied

Study of the dependence of human monocytes and macrophages antitumoral properties upon TNF-alpha expression or release.

This study compares the antitumoral properties of isolated circulating human blood monocytes (Mo) and of mature macrophages (MO) obtained by 7 days differentiation of Mo or isolated from alveolar washing. These cells were activated to cytotoxicity in the presence of recombinant human interferon-gamma (rHuIFN-gamma). This antitumoral effect was measured at a low (1/1) effector/target ratio without pretreatment of the tumor cells. Activated Mo released tumor necrosis factor-alpha (TNF-alpha) in the culture medium where their antitumoral activity could be totally neutralized by specific anti-rHuTNF-alpha antibodies. In contrast, blood monocytes derived macrophages differentiated and activated in vitro expressed TNF-alpha on their membrane where it could be labelled and partially neutralized by anti-rHuTNF-alpha antibodies. Direct effector/target contact was required for the activity of macrophages differentiated in culture or collected from the lung cavity of healthy subjects. When these macrophages were obtained from infected patients or subjected to LPS treatment, they directly released cytotoxic amounts of TNF in the extracellular fluid after activation with IFN-gamma. Monocytes act mainly by soluble mediators (TNF-alpha being a key factor), while differentiated macrophages in the absence of endotoxin act by close cell to cell contact involving the lytic action of membranous TNF-alpha as well as some release of soluble TNF-alpha. We also present evidences (based on the use of various protease inhibitors) that the role of proteases is much less crucial in the cytotoxic action of monocytes and macrophages.

Cytotoxicity, Immunologic↗