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Biomedical subjects

E Vargas

Publications and source records attributed to E Vargas.

At least 19 recordsLinked to original sources
PubMed2006

Health economics assessment study of teicoplanin versus vancomycin in Gram-positive infections.

The objective of this study, conducted at Hospital Clínico San Carlos, Madrid, Spain, was to compare the cost of treatment of Gram-positive infections with teicoplanin and vancomycin under normal conditions. Using a prospective observational study design for drug utilization and economic assessment, we evaluated the comparability of the sample, adverse events, features of treatment with teicoplanin/vancomycin and factors influencing the consumption of resources until the end of glycopeptide treatment or discharge (whichever occurred later) using Health System perspective. Costs were assigned using the hospital's evaluation at the time of the study. Analyses made: multivariate, sensitivity (by modifying staff or acquisition costs) and simulation of reduction of stay by early discharge in the teicoplanin group. Study participants included 201 patients who had been using teicoplanin (n=100) or vancomycin (n=101) for at least four days. Data collected daily outside morning work timetable. Costs of acquisition, administration and monitoring by course of treatment (mean+/-SD, in euros) were lower in the vancomycin group (teicoplanin euro647.62+/-euro572.75 vs. vancomycin euro378.11+/-euro225.90); when total costs (including hospital stay) were considered, no differences were found (teicoplanin euro4,432.04+/-euro3,383.46 vs. vancomycin euro4,364.44+/-euro2,734.24). Conditions of use and results were similar for both antibiotics. The economic results of acquisition, administration and monitoring were advantageous for vancomycin; when global costs of care were taken into account, these differences were not evident. Tolerability was significantly advantageous in the teicoplanin group (with regard to phlebitis and elevation of creatininemia), without differences in clinical or economic outcomes. The formulation of teicoplanin did not take advantage of its potential benefits of administration.

Adult↗
PubMed2005

Phlebotonics for venous insufficiency.

BACKGROUND: Chronic venous insufficiency (CVI) is a common condition caused by inadequate blood flow through the veins, usually in the lower limbs. It can result in considerable discomfort with symptoms such as pain, itchiness and tiredness in the legs. Sufferers may also experience swelling and ulcers. Phlebotonics are a class of drugs that are often used to treat CVI. OBJECTIVES: To assess the efficacy of oral or topical phlebotonics. SEARCH STRATEGY: We searched the Cochrane Peripheral Vascular Diseases Group trials register (April 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2005), MEDLINE (January 1966 to April 2005), EMBASE (January 1980 to April 2005) and reference lists of articles. We also contacted pharmaceutical companies. SELECTION CRITERIA: Randomised, double blind, placebo-controlled trials (RCTs) assessing the efficacy of rutosides, hidrosmine, diosmine, calcium dobesilate, chromocarbe, centella asiatica, disodium flavodate, french maritime pine bark extract, grape seed extract and aminaftone in CVI patients at any stage of the disease. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data and assessed trial quality. The effects of treatment were estimated by relative risk (RR) or by standardised mean differences (SMD) by applying a random effects statistical model. Sensitivity analyses were also performed. MAIN RESULTS: Fifty-nine RCTs of oral phlebotonics were included, but only 44 trials involving 4413 participants contained quantifiable data for the efficacy analysis: 23 of rutosides, ten of hidrosmine and diosmine, six of calcium dobesilate, two of centella asiatica, one of french maritime pine bark extract, one of aminaftone and one of grape seed extract. No studies evaluating topical phlebotonics, chromocarbe, naftazone or disodium flavodate fulfilled the inclusion criteria. Outcomes included oedema, venous ulcers, trophic disorders, subjective symptoms (pain, cramps, restless legs, itching, heaviness, swelling and paraesthesias), global assessment measures and side effects. The results of many variables were heterogeneous. Phlebotonics showed some global benefit (i.e. oedema reduction) (relative risk 0.72, 95% confidence interval 0.65 to 0.81). The benefit for the remaining CVI signs and symptoms must be evaluated by phlebotonic group. There were no quantifiable data on quality of life. AUTHORS' CONCLUSIONS: There is not enough evidence to globally support the efficacy of phlebotonics for chronic venous insufficiency. There is a suggestion of some efficacy of phlebotonics on oedema but this is of uncertain clinical relevance. Due to the limitations of current evidence, there is a need for further randomised, controlled clinical trials with greater attention paid to methodological quality.

4-Aminobenzoic Acid↗
PubMed2004

Maternal adaptation to high-altitude pregnancy: an experiment of nature--a review.

A long and productive history of studies at high altitude has demonstrated that chronic hypoxia plays a key role in the aetiology of intrauterine growth restriction (IUGR) and pre-eclampsia. Susceptibility to altitude-associated IUGR varies among high-altitude populations in relation to their duration of altitude exposure, with multigenerational residents demonstrating one-third the birth weight fall present in shorter-resident groups. Higher uteroplacental blood flow during pregnancy in multigenerational high-altitude residents suggests that such population differences are due, at least in part, to differences in maternal vascular responses to pregnancy. We hypothesize that natural selection acting on hypoxia-inducible factor (HIF)-targeted or -regulatory genes has enabled maternal vascular adaptation to pregnancy in long-resident high-altitude groups. Preliminary evidence in support of this hypothesis demonstrates that the potent HIF-targeted vasoconstrictor, endothelin-1 (ET-1), is differentially regulated by pregnancy and chronic hypoxia in Andean vs European residents of high altitude. Andeans show the normal, pregnancy-associated fall in ET-1 levels previously reported at low altitude, whereas Europeans have higher ET-1 levels and little pregnancy-associated change, like pre-eclamptic women. Single nucleotide polymorphisms (SNPs) in the ET-1 gene also differ in Andeans compared with low-altitude populations. We conclude that high altitude serves as an experiment of nature for elucidating genetic factors underlying susceptibility to complications of pregnancy and fetal life. Such studies may be important for identifying persons at risk for these complications at any altitude.

Acclimatization↗
PubMed2002

Reproduction in high altitude Aymara: physiological stress and fertility planning?

Reproductive characteristics at high altitude are described based on the reproductive histories of 720 Aymara women, collected in 1998 and 1999 in a group of twelve peasant communities at a mean altitude of 4000 m in the Bolivian Altiplano. The reproductive pattern is shaped by a late onset of childbearing, associated with a rather short reproductive span and large birth intervals. Environmental conditions could explain the particularly late age at menarche of rural girls compared with their urban counterparts, whereas the age at first birth is likely to be under cultural control. The short reproductive span appears to result from a large mean interval between last birth and menopause, which is essentially determined by cultural decisions. The birth intervals, which are longer than in many traditional societies, could be the result of a slower restoration of postpartum fecundability induced by the hard way of life inherent in the Altiplano (including poor sanitary and nutritional conditions and high workload), perhaps aggravated by hypoxia. However, a secular trend in fertility is perceptible, towards earlier menarche, earlier age at first birth, increasing reproductive span and a slight increase in live births and surviving offspring, which is probably the result of a slow improvement in living conditions. The existence of birth control on the one hand, and a total fertility rate averaging six live births among the couples who do not practise contraception on the other, are other arguments against the hypothesis of a low natural fecundity in these Aymara groups.

Adolescent↗
PubMed2002

Platelet aggregation in different antithrombotic regimens. Possible proaggregant effect of low level oral anticoagulation.

UNLABELLED: Few trials have studied platelet activity during oral anticoagulation and all show a tendency for platelet aggregation to increase. This adverse effect has also been shown in some patients treated with unfractionated heparin, the so-called white clot syndrome. We studied platelet aggregation in patients with atrial fibrillation enrolled in the NASPEAF study and receiving antiaggregant, anticoagulant and both treatments. METHODS: 15 healthy control subjects (group C) and 99 patients were enrolled, the latter receiving 4 different antithrombotic regimens for platelet aggregation: group 1, 600 mg of the antiplatelet drug triflusal; group 2, anticoagulation for an INR of 2-3; and both treatments with 2 different levels of anticoagulation, mean INR of 1.85 (group 3) and of 2.15 (group 4). The same amounts of the agonists ADP, arachidonic acid and collagen were used in all tests. For statistical analysis we used the interval in min, from the addition of the agonist to the beginning of aggregation and the % of aggregation at 5 and 8 min. RESULTS: After arachidonic acid was given, the interval to the beginning of aggregation was shorter in group 2 than in group C: 0.6 +/- 0.21 and 1.1 +/- 1.2, and in both was significantly shorter than in the other three receiving antiplatelet drugs alone: group 1 = 1.58 +/- 1.4 or combined with anticoagulants: group 3 = 1.7 +/- 1.7 and group 4 = 2.4 +/- 2.1. The % of aggregation at 5 min, in groups C, 2, 1, 3 and 4 was respectively 48 +/- 24, 43.2 +/- 19, 29.6 +/- 17, 34.8 +/- 22 and 23.2 +/- 22.5. The data showed significantly increased platelet activity in groups C and 2 compared to groups 1, 3 and 4. Group 3 with a low anticoagulation level (mean INR = 1.85) showed a tendency to greater platelet activity than group 1 and 4 with p value = 0.08. CONCLUSIONS: The antiplatelet drug triflusal alone or combined with a therapeutic level of anticoagulation effectively reduces platelet aggregation and is not influenced by anticoagulant treatment. A low level of anticoagulation (INR < 2) shows a tendency to increase platelet activity.

Acenocoumarol↗
PubMed2001

Combined treatment of giant-cell arteritis with methotrexate and prednisone. a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Corticosteroids remain the cornerstone of therapy for giant-cell arteritis, but relapse during dose tapering and corticosteroid-related adverse events often complicate management of this condition. Although several approaches, including combined therapy with cytotoxic agents, have been suggested to overcome these problems, no study has clearly shown benefits of alternate treatments. OBJECTIVE: To analyze the safety and efficacy of combined therapy with corticosteroids and methotrexate in giant-cell arteritis. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: University-based clinic. PATIENTS: 42 patients with new-onset giant-cell arteritis according to biopsy. INTERVENTION: High initial doses of corticosteroid were given; the dose was then tapered quickly until therapy was completely withdrawn. Methotrexate or placebo was given weekly from the start of corticosteroid therapy for 24 months. MEASUREMENTS: Number of relapses, cumulative dose of corticosteroid, and number of adverse events were assessed on completion of follow-up. RESULTS: Compared with combined prednisone and placebo therapy, treatment with prednisone and methotrexate reduced the proportion of patients who experienced at least one relapse (45% vs. 84.2%; P = 0.02) and the proportion of patients who experienced multiple relapses (P = 0.004). The mean cumulative dose of prednisone was 4187 +/- 1529 mg in the methotrexate group and 5489.5 +/- 1396 mg in the placebo group (mean difference, 1302 mg [95% CI, 350 to 2253 mg]; P = 0.009). Overall, the rate and severity of adverse events were similar between groups. Treatment was discontinued in 3 patients in the methotrexate group who experienced definite drug-related adverse events. In sensitivity analysis that included patients lost to follow-up, differences between groups in number of relapses and cumulative dose of prednisone were significant. CONCLUSIONS: Treatment with methotrexate plus corticosteroid is a safe alternative to corticosteroid therapy alone in patients with giant-cell arteritis and is more effective in controlling disease.

Adrenal Cortex Hormones↗
PubMed2001

Assessment of hospital costs related to the diagnosis and treatment of upper gastrointestinal haemorrhages in patients consuming non steroid anti-inflammatory drugs.

BACKGROUND: Non-steroid anti-inflammatory drugs (NSAIDs) can produce haemorrhages of the digestive tract, whose treatment result in significant hospital costs. OBJECTIVE: The aim of this analysis has been to estimate hospital costs related to the treatment of digestive haemorrhages potentially caused by the intake of NSAIDs. MATERIAL AND METHODS: The study was conducted by reviewing the clinical history of all patients admitted in two tertiary Spanish hospitals during 1998 due to digestive haemorrhage following NSAID treatment. After the identification of cases, all resources consumed during their hospitalisation (concomitant medication, complementary examinations and tests, surgery, blood products consumption, inpatient consultations and length of stay in the hospital) until the complete resolution of each case, were recorded. RESULTS: Thirty-six percent of patients admitted due to digestive haemorrhage had taken some NSAID the same day of their hospitalisation (85.4%) or in previous days. The cost related to the treatment of these patients amounted to some 71 million pesetas for both hospitals, with a cost/patient of 434,407 pesetas. CONCLUSIONS: Given the high consumption of NSAIDs in our normal clinical setting, costs related to the diagnosis and treatment of digestive haemorrhages in hospitals are a highly significant burden for the National Health System.

Adolescent↗
PubMed2001

[Severe gastrointestinal complications potentially associated with the use of non-steroidal anti-inflammatory agents: hospital treatment costs for the National Health System of our country].

BACKGROUND: Non-steroidal antiinflammatory drugs (NSAIDs) produce severe gastrointestinal (G-I) complications in 1-4% of cases which need to be treated into the hospital. The aim of this study has been to assess the hospital cost secondary to treat these complications in our National Health Service (NHS). MATERIAL AND METHODS: In the first phase a cross-sectional study was performed in order to know the number of patients who were hospitalized due to a severe G-I complication during 1998 in two tertiary hospital in our country. It was reviewed their clinical charts to know whether they had taken any NSAIDs. In those positive cases all resources used during the hospitalization were collected. RESULTS: In both hospitals studied 38.1% of hospitalized patients for a severe G-I complication had taken any NSAIDs during the same day or previous days. The cost/patient was of 389,831 pesetas. During 1998 in the whole NHS there were 54,623 hospitalizations owing to the same reason. Assuming that 38.1% of them had also taken any NSAIDs, 20,811 patients would have suffered a severe G-I complication potentially due to the intake of NSAIDs. Extrapolating the cost/patient obtained in both hospitals to the global number of patients hospitalized into the NHS, the cost of treating all severe G-I complications related to the consumption of NSAIDs during 1998 was of 8,112 millions pesetas. CONCLUSIONS: Bearing in mind the elevated prevalence of osteo-articular pathology in our country and the high consumption of NSAIDs for its treatment, the coming of new therapeutic options with a better safety profile would mean an important resources' saving for our NHS.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

Beta-ketothiolase genes in Azotobacter vinelandii.

Azotobacter vinelandii is proposed to contain a single beta-ketothiolase activity participating in the formation of acetoacetyl-CoA, a precursor for poly-beta-hydroxybutyrate (PHB) synthesis, and in beta-oxidation (Manchak, J., Page, W.J., 1994. Control of polyhydroxyalkanoate synthesis in Azotobacter vinelandii strain UWD. Microbiology 140, 953-963). We designed a degenerate oligonucleotide from a highly conserved region among bacterial beta-ketothiolases and used it to identify bktA, a gene with a deduced protein product with a high similarity to beta-ketothiolases. Immediately downstream of bktA, we identified a gene called hbdH, which encodes a protein exhibiting similarity to beta-hydroxyacyl-CoA and beta-hydroxybutyryl-CoA dehydrogenases. Two regions with homology to bktA were also observed. One of these was cloned and allowed the identification of the phbA gene, encoding a second beta-ketothiolase. Strains EV132, EV133, and GM1 carrying bktA, hbdH and phbA mutations, respectively, as well as strain EG1 carrying both bktA and phbA mutations, were constructed. The hbdH mutation had no effect on beta-hydroxybutyryl-CoA dehydrogenase activity or on fatty acid assimilation. The bktA mutation had no effect on beta-ketothiolase activity, PHB synthesis or fatty acid assimilation, whereas the phbA mutation significantly reduced beta-ketothiolase activity and PHB accumulation, showing that this is the beta-ketothiolase involved in PHB biosynthesis. Strain EG1 was found to grow under beta-oxidation conditions and to possess beta-ketothiolase activity. Taken together, these results demonstrate the presence of three genes coding for beta-ketothiolases in A. vinelandii.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed2000

Comparative aspects of high-altitude adaptation in human populations.

The conditions and duration of high-altitude residence differ among high-altitude populations. The Tibetan Plateau is larger, more geographically remote, and appears to have been occupied for a longer period of time than the Andean Altiplano and, certainly, the Rocky Mountain region as judged by archaeological, linguistic, genetic and historical data. In addition, the Tibetan gene pool is less likely to have been constricted by small numbers of initial migrants and/or severe population decline, and to have been less subject to genetic admixture with lowland groups. Comparing Tibetans to other high-altitude residents demonstrates that Tibetans have less intrauterine growth retardation better neonatal oxygenation higher ventilation and hypoxic ventilatory response lower pulmonary arterial pressure and resistance lower hemoglobin concentrations and less susceptibility to CMS These findings are consistent with the conclusion that "adaptation" to high altitude increases with time, considering time in generations of high-altitude exposure. Future research is needed to compare the extent of IUGR and neonatal oxygenation in South American high-altitude residents of Andean vs. European ancestry, controlling for gestational age and other characteristics. Another fruitful line of inquiry is likely to be determining whether persons with CMS or other altitude-associated problems experienced exaggerated hypoxia during prenatal or neonatal life. Finally, the comparison of high-altitude populations with respect to the frequencies of genes involved in oxygen sensing and physiologic response to hypoxia will be useful, once candidate genes have been identified.

Acclimatization↗
PubMed2000

Expression and one-step purification of Plasmodium proteins in dictyostelium.

Nearly full-length Circumsporozoite protein (CSP) from Plasmodium falciparum, the C-terminal fragments from both P. falciparm and P. yoelii CSP and a fragment comprising 351 amino acids of P.vivax MSPI were expressed in the slime mold Dictyostelium discoideum. Discoidin-tag expression vectors allowed both high yields of these proteins and their purification by a nearly single-step procedure. We exploited the galactose binding activity of Discoidin Ia to separate the fusion proteins by affinity chromatography on Sepharose-4B columns. Inclusion of a thrombin recognition site allowed cleavage of the Discoidin-tag from the fusion protein. Partial secretion of the protein was obtained via an ER independent pathway, whereas routing the recombinant proteins to the ER resulted in glycosylation and retention. Yields of proteins ranged from 0.08 to 3 mg l(-1) depending on the protein sequence and the purification conditions. The recognition of purified MSPI by sera from P. vivax malaria patients was used to confirm the native conformation of the protein expressed in Dictyostelium. The simple purification procedure described here, based on Sepharose-4B, should facilitate the expression and the large-scale purification of various Plasmodium polypeptides.

Animals↗
PubMed2000

Lag time between onset of symptoms and access to rheumatology care and DMARD therapy in a cohort of patients with rheumatoid arthritis.

OBJECTIVE: To study demographic and clinical variables associated with a longer delay in disease modifying antirheumatic drug (DMARD) therapy initiation in a cohort of patients with rheumatoid arthritis (RA). METHODS: We studied 527 new RA patients (74.3% female, median age at symptom onset 55 yrs) in a hospital setting who fulfilled the ACR criteria for the diagnosis of RA. Demographic, clinical, laboratory, and treatment variables were collected longitudinally into a computerized research database. Risk factors for delay in use of DMARD therapy and first evaluation by a rheumatologist were analyzed using a Cox regression model. RESULTS: The median lag time between symptom onset and first rheumatologist encounter was 17 months and between onset of symptoms and first DMARD therapy 19 months. Variables associated with longer delay to DMARD therapy were the lag time between symptom onset and first rheumatologist visit (RR 0.73, 95% CI 0.71-0.76) and years of education. Variables associated with longer delay in first visit with rheumatologist were swollen/tender joint count, age at symptom onset, home support, labor force status, marital status, and years of education. CONCLUSION: Awareness of factors associated with a longer delay in access to rheumatology care and DMARD therapy may help break down barriers that prevent their early access, irrespective of patient age, socioeconomic status, initial symptoms, or need for treatment.

Adult↗
PubMed1999

Percent of oxygen saturation of arterial hemoglobin among Bolivian Aymara at 3,900-4,000 m.

A range of variation in percent of oxygen saturation of arterial hemoglobin (SaO2) among healthy individuals at a given high altitude indicates differences in physiological hypoxemia despite uniform ambient hypoxic stress. In populations native to the Tibetan plateau, a significant portion of the variance is attributable to additive genetic factors, and there is a major gene influencing SaO2. To determine whether there is genetic variance in other high-altitude populations, we designed a study to test the hypothesis that additive genetic factors contribute to phenotypic variation in SaO2 among Aymara natives of the Andean plateau, a population geographically distant from the Tibetan plateau and with a long, separate history of high-altitude residence. The average SaO2 of 381 Aymara at 3,900-4,000 m was 92+/-0.15% (SEM) with a range of 84-99%. The average was 2.6% higher than the average SaO2 of a sample of Tibetans at 3,800-4,065 m measured with the same techniques. Quantitative genetic analyses of the Aymara sample detected no significant variance attributable to genetic factors. The presence of genetic variance in SaO2 in the Tibetan sample and its absence in the Aymara sample indicate there is potential for natural selection on this trait in the Tibetan but not the Aymara population.

Adaptation, Physiological↗
PubMed1999

Developmental components of resting ventilation among high- and low-altitude Andean children and adults.

This paper evaluates the age-associated changes of resting ventilation of 115 high- and low-altitude Aymara subjects, of whom 61 were from the rural Aymara village of Ventilla situated at an average altitude of 4,200 m and 54 from the rural village of Caranavi situated at an average altitude of 900 m. Comparison of the age patterns of resting ventilation suggests the following conclusions: 1) the resting ventilation (ml/kg/min) of high-altitude natives is markedly higher than that of low-altitude natives; 2) the age decline of ventilation is similar in both lowlanders and highlanders, but the starting point and therefore the age decline are much higher at high altitude; 3) the resting ventilation that characterizes high-altitude Andean natives is developmentally expressed in the same manner as it is at low altitude; and 4) the resting ventilation (ml/kg/min) of Aymara high-altitude natives is between 40-80% lower than that of Tibetans.

Adaptation, Physiological↗
PubMed1999

[Sexuality and the human body: the subject's view through video images].

This study analyzes images of the body linked to sexual and reproductive behavior found in the communication processes mediated by so-called educational videos. In the relationship between subject and technology, the paper is intended to characterize the discourses and the view or perspective currently shaping health education practices. Focusing on the potential in the relationship between the enunciator and subjects represented in the text and the interaction between health professionals and messages, the study attempts to characterize the discourses and questions providing the basis for a given view of the body and sexuality. The study was conducted in the years 1996-1997 and focused on health professionals from the public health system. The results show a concept of sexuality that tends to generalize the meaning ascribed to sexual experience, ignoring the various ways by which different culturally defined groups attribute meaning to the body.

Attitude↗
PubMed1999

[Control of pediatric nosocomial bacteremia by a program based on culturing of parenteral solutions in use].

OBJECTIVE: As Klebsiella, Enterobacter and Serratia are capable of growth in i.v. fluids and these bacteria are commonly implicated in nosocomial bacteremia, a control strategy through microbiological surveillance of in-use parenteral solutions is proposed. MATERIAL AND METHODS: A second level general teaching hospital, serving low-income patients. Through four consecutive strategies, a continuous surveillance program of i.v. fluids sterility in pediatric wards was stablished in 1992. During the first stage all of the in-use solutions were cultured. During the second stage randomly selected samples were studied. Third stage was designed as a case-control study. The last stage included samples drawn in convenience. Positive cultures point out eventual infusion mishandling, as well as high-risk areas and patients. RESULTS: After culturing 1940 parenteral solutions, infusion contamination rates decreased from 29.6% in 1992 to 12.9% in 1997 (p < 0.001). The proportion of Gram-negative rods isolated from blood cultures went from 72.7% to 40.85% (p < 0.0001), and the nosocomial bacteremia rate dropped from 3.12 to 1.54 per 100 discharges. CONCLUSIONS: The program has enabled us to: 1) Detect and control eventual bacteremia outbreaks; 2) Assess the endemic infusion contamination rate; 3) Arouse healthcare workers awareness about infusion line precautions; 4) Have a suitable surveillance strategy according to our laboratory's workload.

Bacteremia↗