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Biomedical subjects

I Hurtado

Publications and source records attributed to I Hurtado.

At least 19 recordsLinked to original sources
PubMed2006

Effect of education on overall and cause-specific mortality in injecting drug users, according to HIV and introduction of HAART.

BACKGROUND: We assessed the impact of education on long-term overall and cause-specific mortality among 6575 injecting drug users (IDUs) according to HIV status and introduction of highly active antiretroviral therapy (HAART). METHODS: Community-based cohort study of IDUs recruited in three AIDS prevention centres (1987-1996). Causes of death were ascertained in clinical centres and Mortality Registry and classified as AIDS, drug use related, injuries, or liver diseases. Poisson regression models including education and calendar period interaction and adjusted by sex, age, and HIV were used. RESULTS: In 73 901 person-years of follow-up, there were 1493 deaths (20.2/1000 person-years): 761 related to AIDS, 234 to drug use, 179 to injuries, and 93 to liver diseases. IDUs with university studies had a lower risk of death (RR 0.52; 95% CI 0.36-0.77) than those without studies: this difference was higher after (RR 0.45; 95% CI 0.25-0.80) than before 1997 (RR 0.68; 95% CI 0.41-1.13). Compared to before 1997, while decreases in the risk of AIDS mortality were seen during 1997-2004 for both lower (RR 0.49; 95% CI 0.41-0.58) and higher (RR 0.33; 95% CI 0.23-0.48) educated, only those higher educated experienced a reduction in drug-use mortality (RR 0.54; 95% CI 0.28-1.05) and death from injuries (RR 0.52; 95% CI 0.23-1.21). CONCLUSIONS: Independently of HIV status, lower education predicts a higher risk of death in IDUs and its impact is stronger after 1997. Education has a protective effect on most causes of death and it cannot be entirely attributable to the access or use of HAART.

Acquired Immunodeficiency Syndrome↗
PubMed2006

Trends in HIV testing, serial HIV prevalence and HIV incidence among people attending a Center for AIDS Prevention from 1988 to 2003.

AIM: To analyse trends in HIV testing, serial HIV prevalence and HIV incidence among people who underwent voluntary testing in a Center for AIDS Prevention in Valencia, Spain. METHODS: Open cohort study including all subjects who went to the Center for AIDS Prevention from 1988 to 2003. Information on sociodemographic variables and HIV test results was collected. Serial prevalence and incidence rates were calculated, and joinpoint regression was used to identify changes in trends over time. RESULTS: 21,241 subjects were analysed; 67% men, 27% injecting drug users (IDUs), 43% heterosexuals and 13% men who have sex with men (MSM). From 1988 to 1990, IDUs accounted for 57% of clinic attenders, decreasing to 14% by 1997-2003, accompanied by an increase in heterosexuals. Overall, HIV prevalence for the whole period was 15%, dropping from 35% to <10% after 1999 and to 3% by 2003, when HIV prevalence was 26% in IDUs, 6% in MSM and 2% in heterosexuals. Total HIV incidence was 2.5%. From 1988 to 1990, HIV incidence ranged from 6% to 8%, and a gradual and progressive decline observed from 1990 onwards. From 1995 onwards, HIV incidence was <2%. The highest incidence rate is seen in IDUs, 7-12% in the first period and 4-5% at the end. Among MSM, a change in the decreasing trend is seen by 1998, and increases in incidence are detected by 2002-3. CONCLUSIONS: Serial HIV prevalence has markedly decreased from 1988 in all transmission categories, although it is still high. With regard to HIV incidence, the drop has been marked too, although a worrying increase, that requires further follow-up, has been detected in MSM in the past 2 years.

Adolescent↗
PubMed2003

Relation between leptin and body fat distribution in menopausal status.

We examined the serum concentrations of leptin in a homogeneous group of 52 postmenopausal Mediterranean women, calculating body fat mass distribution by waist-to-hip circumference ratio (WHR) and other anthropometric measurements. Significant correlations were found between leptin and weight (r=0.59), Body Mass Index (BMI) (r=0.56), Conicity Index (CI) (r=0.49) and all circumferences measured: chest (r=0.55), waist (0.61) and hip (r=0.65), but not between leptin and WHR. Leptin levels does not seem to be influenced by fat mass distribution (android or gynoid type) while weight gain over life appears to be related with the hormone concentration when menopausal status is well established.

Adipose Tissue↗
PubMed2002

[Effect of cyclosporin and tacrolimus on lipoprotein oxidation after renal transplantation].

BACKGROUND: Cyclosporin A is a lipogenic immunosuppressor that can induce posttransplant hyperlipidaemia. Oxidation of low-density lipoprotein (LDL) has been recognized as a major atherogenic factor. Tacrolimus seems to be less lipogenic with an apparently better cardiovascular profile than CsA. METHODS: We have studied the lipidic profile and the oxidation of HDL and LDL in 20 renal transplant patients, 12 male and 8 female, mean age 45 +/- 10 year, who where switched from CsA to tacrolimus due to CsA adverse effects. LDL were determined by ultracentrifugation. Oxidation study before and 6 months after conversion to tacrolimus was performed by adding CuSO4. RESULTS: After conversion, systolic blood pressure (BP) decreased from 154 +/- 21 to 133 +/- 21 mm Hg (p = 0.008), diastolic BP from 97 +/- 13 to 77 +/- 15 mm Hg (p = 0.016), total cholesterol from 6.08 +/- 0.9 to 5.68 +/- 1.1 mmol/l (p = 0.02), LDL-chol from 3.29 +/- 1.01 to 2.96 +/- 0.3 mmol/l (p = 0.04) and apo-B lipoprotein from 1.42 +/- 0.28 to 1.15 +/- 0.34 mg/dl (p = 0.003). The oxidation of LDL improved after conversion: the initial dienic compounds decreased from 95 +/- 20 to 63 +/- 12 umol/g and the final DC from 207 +/- 56 to 107 +/- 35 umol/g. Lag-phase increased from 33 +/- 21 to 45 +/- 17 min (p < 0.05). CONCLUSION: Tacrolimus has improved hyperlipidaemia in our cyclosporin previously treated patients and increased the resistance to oxidation of high and low-density lipoproteins.

Adult↗
PubMed2001

Thermodynamic modeling of PCDD/Fs formation in thermal processes.

Three thermodynamic databases of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), derived using the Group Additivity approach and two computational molecular modeling methods, Modified Neglect of Diatomic Overlap (MNDO) and Parametrized Model 3 (PM3), respectively, combined with the Scientific Group Thermodata Europe (SGTE) database have been used to model the formation of PCDD/Fs in thermal processes, such as iron ore sintering process. The predictions using the three different databases are compared, and similar thermodynamic conditions of PCDD/Fs formation are found. The comparison of the calculated values with measured results obtained from industrial iron ore sinter plant indicates that the PCDDs and PCDFs found in practice are not in equilibrium with each other. While within each dioxin and furan homologue equilibrium between the isomers appears to be established in industrial processes, reactions between dioxins and furans seem to be kinetically inhibited. This view has been supported by assuming no reaction at all between PCDFs and PCDDs in the simulation. With this assumption, both PCDFs and PCDDs reached partial pressures between 600 and 800 K in the order of magnitude actually found in practice. Taking this restriction into account, the conditions for PCDD/Fs formation were calculated as a function of oxygen partial pressure; temperature; concentrations of carbon, hydrogen, and chlorine; and C/H ratio.

Benzofurans↗
PubMed2000

Influence of serum amyloid A on the decrease of high density lipoprotein-cholesterol in active sarcoidosis.

OBJECTIVE: We have previously observed low levels of high density lipoprotein (HDL) cholesterol in active sarcoidosis. The aim of this study was to analyze the role of serum amyloid A (SAA) on this lipid disorder. METHODS: Eighty five untreated sarcoid patients, 40 with active disease and 45 with inactive disease, were recruited. Sarcoidosis activity was evaluated by means of clinical, chest X-ray, gallium-67 scan, serum angiotensin converting enzyme (peptidyl-dipeptidase A) values, and pulmonary function tests. Analysis of lipoprotein metabolism included: serum cholesterol, low density lipoprotein (LDL)-cholesterol, HDL-cholesterol, HDL(2)-cholesterol, HDL(3)-cholesterol, apolipoprotein A-I (apo A-I), apolipoprotein B (apo B), and triglyceride concentrations. Serum amyloid A protein and lecithin-cholesterol acyltransferase (LCAT) activity were measured. RESULTS: In active sarcoidosis we found significantly reduced levels of HDL-cholesterol (1.17+/-0.36 vs. 1. 44+/-0.39 mmol/l, P=0.002), HDL(3)-cholesterol (0.78+/-0.23 vs. 1. 02+/-0.21 mmol/l, P<0.0001), and apo A-I (1.36+/-0.29 vs. 1.61+/-0. 27 g/l, P<0.0001) and significantly increased levels of triglyceride (1.51+/-0.64 vs. 1.03+/-0.46 mmol/l, P<0.0001), and apo B (1.14+/-0. 25 vs. 0.99+/-0.27 g/l, P=0.012) versus inactive sarcoidosis. Serum amyloid A concentrations were significantly increased in the patients with active disease (155.45+/-154.01 mg/ml) compared to the inactive sarcoid patients (89.70+/-65.36 mg/ml) (P=0.011). There were no significant differences in cholesterol, LDL-cholesterol, HDL(2)-cholesterol or LCAT values between groups. Multivariate logistic regression analysis showed that HDL-cholesterol (regression coefficient b=-1.96; S.E.=0.87; P=0.02) and SAA (regression coefficient b=0.01; S.E.=0.004; P=0.01) were the two variables independently associated with disease activity. Moreover, a significant negative correlation was observed between SAA levels and both HDL-cholesterol (r=-0.39; P=0.01) and apo A-I (r=-0.35; P=0.03) levels, in the active sarcoid group. Conversely, no correlation was found in the inactive sarcoid group. CONCLUSION: The low HDL-cholesterol and apo A-I concentrations seen in active sarcoid patients are associated with a significant increase of SAA levels. We suggest that the displacement of apo A-I by SAA on HDL accounts for the lower level of HDL-cholesterol seen in active sarcoidosis.

Adult↗
PubMed2000

Liver xenotransplantation: changes in lipid and lipoprotein concentration after long-term graft survival.

BACKGROUND/AIMS: Today, scientists devote considerable effort to the study of mechanisms of xenograft rejection, but with liver xenotransplantation (XTx) researchers face the added problem of metabolic incompatibility between species. To date, there have been few studies of molecular xenogeneic interactions, perhaps because little progress has been made in solving immunological problems. This study is an initial analysis of lipoprotein metabolism in a hamster-to-rat hepatic xenotransplantation model. METHODS: There were 6 experimental groups (n=8): (1) male Sprague-Dawley (S.D.) rats (220-280 g); (2) male Golden Syrian hamsters (100-150 g); (3) S.D. rats, "sham" operation with immunosuppression; (4) S.D. rat-to-S.D. rat alloTx; (5) S.D. rat-to-S.D. rat alloTx with immunosuppression; (6) XTx hamster G.S-to-S.D. rat with immunosuppression. Mofetil mycophenolate (25 mg/kg/d) was administered for 14 days and FK506 (0.2 mg/kg/d) for 45 days (groups 3, 5 and 6). After 24 h fasting, animals were sacrificed (day +50 postransplantation) and a complete lipoprotein profile was determined. Serum lipoproteins were subfractioned by ultracentrifugation in density gradient. RESULTS: There was a large increase in serum lipid levels in xenografted rats compared with control rats and allografted rats. Xenografted rats presented a severely altered lipoprotein profile compared with normal rats. Surprisingly, the characterisation of lipoproteins in xenografted rats displayed the same composition as donor animals. Histological study did not show signs of alteration of the hepatic architecture. CONCLUSIONS: Since the liver is the main solid organ co-ordinator of metabolic pathways, such as lipid metabolism, hepatic xenotransplantation makes changes in lipid concentrations in the recipient and also changes in lipid compositions of lipoproteins. Hepatic xenotransplantation is not a feasible solution given the organ's metabolic complexity.

Animals↗
PubMed1999

Fluvastatin and low-density lipoprotein oxidation in hypercholesterolemic renal transplant patients.

BACKGROUND: Hyperlipidemia contributes to the development and progression of vascular disease in organ transplant patients. Oxidative modification of low-density lipoproteins (LDLs) has been suggested as a key event in early atherogenesis. METHODS: We conducted a pilot study in renal transplanted patients with persistent hypercholesterolemia above 6.5 mmol/liter. We studied the LDL oxidation before and after one year of fluvastatin treatment. Twenty patients (12 males and 8 females, 46 +/- 10 years old) who received a kidney transplant 24 +/- 18 months before the study were treated with fluvastatin (20 mg/day for 12 weeks). Patients with a total cholesterol under 6.3 mmol/liter continued to receive 20 mg/day for another 40 weeks (group I, N = 10). Nine patients with a total cholesterol above 6.3 mmol/liter received 40 mg/day for a further 40 weeks (group II). RESULTS: Cyclosporine levels did not experience a significant variation. Total and LDL cholesterol decreased significantly in both groups (21.7 and 27.9% in group I, 18.3 and 27.2% in group II, respectively). The lag-phase time, which was significantly enlarged before fluvastatin treatment in the patients with respect to the controls (N = 18, 82 +/- 45 vs. 50 +/- 8 min) was shortened after one year of fluvastatin treatment (64 +/- 24 vs. 50 +/- 8 min, P = 0.04). Fluvastatin was stopped in only one patient because of nausea and vomiting. Transaminases and creatin-phospho-kinase were not altered. All of the patients maintained a functioning graft during the study period. CONCLUSIONS: Fluvastatin significantly reduced total and LDL cholesterol, without interferences with cyclosporine A through levels. Fluvastatin has not demonstrated an antioxidant effect in our renal hypercholesterolemic transplant patients.

Adult↗
PubMed1997

Molecular basis of fish-eye disease in a patient from Spain. Characterization of a novel mutation in the LCAT gene and lipid analysis of the cornea.

The genetic and biochemical basis of fish-eye disease (FED) was investigated in a 63-year-old female proband with low plasma HDL cholesterol. Analyses of corneal and plasma lipids of the proband were consistent with impaired lecithin:cholesterol acyltransferase (LCAT) activity. Free cholesterol and phospholipid levels were elevated relative to control values, whereas cholesteryl ester levels were greatly reduced. Fatty acid compositions of corneal lipids from the proband and control subjects differ from the respective fatty acid compositions of their plasma lipids. This suggests that the metabolic pathways and acyl chain specificities for phospholipid, cholesteryl ester, and triglyceride metabolism within the cornea are distinct from those of plasma. Sequencing of the LCAT gene from the proband revealed a novel mutation at nucleotide 399, corresponding to an Arg99-->Cys substitution. Secretion of LCAT (Arg99-->Cys) by transfected COS-6 cells was approximately 50% of that of the wild type, but its specific activity against reassembled HDL was 93% lower than that of wild-type LCAT. The specific activities of wild-type and LCAT (Arg99-->Cys) against LDL were reduced similarly, suggesting that the appearance of the FED phenotype does not require enhanced activity against LDL. Our data support the hypothesis that FED is a partial LCAT deficiency in which poor esterification in specific types of HDL particles may contribute to the appearance of the corneal opacities.

Animals↗
PubMed1996

In vitro oxidised HDL exerts a cytotoxic effect on macrophages.

The cytotoxic effect of native high density lipoprotein (n-HDL) and oxidised high density lipoprotein (ox-HDL) on macrophages was studied and compared with that of low density lipoprotein (LDL). Copper-mediated oxidation of HDL and LDL was conducted in vitro and assessed by the analysis of conjugated dienes (CD). The kinetics of CD production during lipoprotein oxidation showed that HDL, relative to LDL, exhibited a shorter lag phase (47.7 +/- 17.8 vs. 82.9 +/- 24.5 min), higher diene production (242.2 +/- 23.0 vs 210.4 +/- 14.9 nmol/mg lipid) and reached maximal diene concentration in less time (100.0 +/- 35.4 vs 136.4 +/- 27.9 min). The maximal rate of CD production was 5.38 +/- 1.30 nmol/mg lipid/min for HDL and 4.42 +/- 0.60 nmol/mg lipid/min for LDL. Vitamin E concentration was higher in HDL than in LDL (2.76 +/- 0.41 vs. 2.19 +/- 0.33 micrograms alpha-tocopherol equivalent/mg lipid). Ox-HDL and oxidised LDL (ox-LDL), under the same experimental conditions, were cytotoxic to macrophages in a dose-dependent manner. At the same protein, or total mass concentration, ox-HDL was less cytotoxic than ox-LDL. However, when both lipoproteins were compared at the same lipid or cholesterol concentrations, ox-HDL was equally or more cytotoxic than ox-LDL. In conclusion, HDL is more susceptible to in vitro oxidation than LDL and the resultant modification of HDL converts this lipoprotein into a cytotoxic particle.

Animals↗
PubMed1994

[Effectiveness of hypercholesterolemia detection in high risk individuals compared to opportunistic detection].

BACKGROUND: The aims of this study were to estimate the number of people who should receive some intervention (pharmacologic and/or dietetic) to reduce cholesterol concentrations and to evaluate selective case finding in comparison to opportunistic detection. METHODS: Six hundred twenty-five individuals participating in a study of cardiovascular risk factors were included in the study. Those with total cholesterol concentrations (TC) greater than 6.2 mmol/l and those with CT concentrations greater than 5.2 mmol/l observed upon lipid profile analysis and history of cardiovascular disease and/or risk factors were considered as candidates. Out of these individuals, those with cholesterol concentrations linked to low density lipoproteins greater than 4.14 mmol/l or greater than 3.37 mmol/l and previous history of cardiovascular disease or two risk factors were considered candidates to undergo intervention to reduce cholesterol concentrations. Moreover, the number of individuals with CT concentrations greater than 6.2 mmol/l which would not be detected if CT was only determined in those who already had another cardiovascular risk factor was estimated. RESULTS: 37.5% (CI 95%; 33.8%-41.5%) of the individuals required lipid profile and out of these 88.8% (CI 95%; 3.8%-92.4%) were candidates to receive intervention. Upon evaluating the efficacy of the strategy of selective case finding it was observed that the sensitivities of the risk factors were low, ranging from 22.6% in those with family history of cardiovascular disease to 34.8% in cases with personal history of high blood pressure. CONCLUSIONS: If selective case finding of high risk subjects was the only strategy applied, many individuals with hypercholesterolemia would remain undetected, therefore the strategy of opportunistic detection is preferable whenever possible.

Adult↗
PubMed1994

An enzyme-linked immunosorbent assay method to measure human apolipoprotein E levels using commercially available reagents: effect of apolipoprotein E polymorphism on serum apolipoprotein E concentration.

A sensitive and specific enzyme-linked immunosorbent assay (ELISA) for human apolipoprotein E (apo E) quantification using commercially available reagents is described. The assay is a noncompetitive, sandwich ELISA in which the wells were coated with a monoclonal EO1 antibody anti-human apo E and detected with a polyclonal antibody-peroxidase conjugate anti-apo E. The mean apo E concentration in 168 middle-aged subjects randomly selected from general population was 51.7 +/- 12.4 mg/liter. Apo E levels were highly correlated with apo E phenotypes. Apo E polymorphism, which shows a modulating effect in the catabolism of apo E containing lipoproteins, may explain a large fraction, 18.5%, of the variability of serum apo E levels in middle-aged population. Isoforms apo E2 and apo E4 have an opposite effect on the regulation of serum apo E concentrations. Individuals that express apo E2 isoform present higher apo E levels (65.5 mg/liter for apo E2/E3), whereas the average of individuals with apo E4 is lower (42.8 mg/liter for apo E4/E3) than general population.

Adult↗
PubMed1991

[Early detection of dyslipidemias. Is the isolated determination of total cholesterol efficient?].

BACKGROUND: The aim of this study was to analyze the percentage of individuals with hypoalphalipoproteinemia and isolated hypertriglyceridemia which would not be detected if only total cholesterol were included in the initial detection of dyslipemia. METHODS: Five hundred forty-one individuals participating in a study concerning factors of cardiovascular risk were included in the present study which consisted in a survey on risk factors and a medical examination. The population studied was divided according to the concentration of total cholesterol (TC) in desirable concentrations (5.2 mmol/l), intermediate (5.2-6.2 mmol/l) and elevated (6.2 mmol/l). The concentrations of cholesterol bound to high density lipoproteins (cHDL) less than 0.9 mmol/l and of triglycerides (TG) greater than 2.3 mmol/l were considered as high risk. RESULTS: Hypoalphalipoproteinemia would not be detected in 2.9% of the population studied (IC 95%: 1.5%-4.3%) and isolated triglyceridemia in 2.4% (IC 95%: 1.1%-3.7%) if the cHDL and the TG were only determined in the individuals who had high or elevated CT concentrations and two or more cardiovascular risk factors. CONCLUSIONS: These data support the efficacy of CT as the only test for initial detection of dyslipemia and question the convenience of initial quantification of cHDL and triglycerides in all cases as some authors request.

Adult↗
PubMed1989

Invasion of a soft contact lens by Exophiala jeanselmei.

The invasion of a soft contact lens by Exophiala jeanselmei is documented. All species in this genus are pathogenic. In humans E. jeanselmei is a recognized cause of mycetoma, phaeohyphomycosis and keratomycosis. This fungus has not been previously listed among lens invaders.

Adult↗
PubMed1987

Air sampling studies in a tropical area. Four year results.

Air sampling studies carried out in Caracas. Venezuela indicate that in this tropical area pollen and fungus spores of allergenic potential are airborne throughout the year. The pollen grains of conifers, mulberry and grasses are the most frequently encountered. Many more fungus spores than pollen grains are recovered from the air; among the former, Cladosporium spores are the most frequent and abundant.

Air↗