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Biomedical subjects

C Calvo

Publications and source records attributed to C Calvo.

At least 19 recordsLinked to original sources
PubMed2003

[Effect of anti-hypertensive therapy with irbesartan on the absolute cardiovascular risk].

Blockade of the renin-angiotensin system with angiotensin converting enzyme inhibitors or with angiotensin receptor antagonists confers patients with arterial hypertension (AH) and associated risk factors, target organ lesion or cardiovascular disease with greater protection in morbidity and mortality terms. The objective of the present study was to evaluate the effect of irbesartan, an angiotensin II receptor antagonist, on the absolute cardiovascular risk in a cohort of hypertensive patients with moderate, high, or very high cardiovascular risk. This was a multicenter, prospective, observational, cohort study with 1974 patients (63 11 years; 47% males) with newly diagnosed essential AH or AH non-controlled with anti-hypertensive monotherapy, and moderate to very high cardiovascular risk. Irbesartan therapy at a dosage of 150300 mg was instituted as monotherapy or associated with hydrochlorothiazide, 12.5 mg. The clinical follow-up was 6 months. The evaluated parameters included the absolute cardiovascular risk, measured either quantitatively (Framingham algorithm) or qualitatively (low, moderate, high, and very high risk groups following the WHO/International Hypertension Society guidelines). Irbesartan therapy led to a significant (p = 0.0001) decrease in SBP (from 170.9 18.4 to 138.5 16.5 mmHg) and DBP (from 96.6 11 to 82 9 mmHg). The quantitative absolute cardiovascular risk decreased by 29.8% (from 12.14 8 to 8.65 6.2; p < 0.0001). The percentage of patients with very high cardiovascular risk decreased from 1.52% to 0.51% and that for patients with high cardiovascular risk from 92.77% to 88.32%. The latter patients changed to the moderate risk group. As a result, this moderate risk group increased from 5.71% to 11.17%. The adverse reaction rate was very low as only 2.2% of patients had some adverse reaction. In conclusion, irbesartan as monotherapy or associated with hydrochlorothiazide has been shown to be effective in reducing the absolute cardiovascular risk, which is obtained by a substantial decrease in arterial pressure and a good safety profile on the biochemical parameters. Tolerability was excellent, with a very low rate of adverse reactions.

Angiotensin Receptor Antagonists↗
PubMed2003

[Usefulness of the Biofeedback Diacontrol module in the automatic programming of plasmatic conductivity and ionic mass transfer].

Programmed variable sodium in the dialysate can improve hypotension during hemodialysis but may also alter sodium balance and thus resulting in a increase of water intake and weight gain between dialysis sessions. The aim of this study was to evaluate the changes on plasma volume (PV), Ionic Mass Transfer (IMT) and plasma conductivity (PC) with two different hemodialysis techniques. We studied 10 patients during a four-period protocol (one week each: PF1-DC1-DC2PF2): 120 dialysis sessions. During periods PF1 and PF2, the dialysis procedure was as usual, with exponential decrease of dialysate conductivity (DC) profile (15.7 mS/cm at start, 14.4 mS/cm at middle and 13.8 mS/cm at the end of the session) and UF profile (1.7 1/h at start and 0.1 1/h at the end). During periods DC1 and DC2, DC was automatically determined by a biofeedback modulae (Diacontrol) in order to reach a plasma water conductivity fixed at 14 mS/cm. All hemodialysis parameters were the same for the four periods: duration, blood and dialysate flow rates, dialysis membrane. A lower reduction of PV was evident on PF1 and PF2 (104 +/- 3.26% and -4.36 +/- 2.7%) compared with DC 1 and DC2 (-6.53 +/- 3.31% and -6.67 +/- 3.12%) (p < 0.001). No significant differences were seen in systolic, mean and diastolic blood pressure pre-HD or post-HD, UF, and weight gain, between the four periods. Hypotensive episodes were seen in 33.3% of PF1, 20% of DC1, 23.3% of DC2 and 26.6% of PF2 sessions (NS). PF1 and PF2 periods resulted in a significantly higher 30', mid and post-dialysis PC as compared to DC1 and DC2 periods (p < 0.001). The mean difference between the actual value and the prescribed value of PC at the end of the session was -0.01 +/- 0.07 mS/cm (n: 60). There was a negative correlation between the mean DC during session and the PC at 30' of session. IMT was 420.73 +/- 126.9 mEq in PF1, 311.96 +/- 161.75 in DC1, 278.34 +/- 153.14 in DC2 and 417.66 +/- 152.17 in PF2 (p > 0.001 PF1 and PF2 vs. DC1 and DC2). Diacontrol determines automatically an individualized DC profile for each patient, and accurately reaches the prescribed PC target. By reaching both the dry weight and PC settings, the water and sodium pool is maintained lower in the hemodialysis session using a biofeedback module. Clinical tolerance was similar in the two different dialysis procedures.

Aged↗
PubMed2002

Characteristics of bioemulsifiers synthesised in crude oil media by Halomonas eurihalina and their effectiveness in the isolation of bacteria able to grow in the presence of hydrocarbons.

Halomonas eurihalina strains F2-7, H28, H96, H212 and H214 were capable of producing large amounts of exopolysaccharides (EPS) in MY medium with added crude oil. The biopolymers showed lower carbohydrate and protein content than those synthesised in control medium without oil. Nevertheless, the percentages of uronic acids, acetyls and sulphates were higher. The emulsifying activity of biopolymers was measured; crude oil was the substrate most efficiently emulsified. Furthermore, all the EPS tested emulsified higher volumes of crude oil than the commercial surfactants used as controls. We have also proved the effectiveness of both Halomonas eurihalina strains and their EPS to select indigenous bacteria able to grow in the presence of polycyclic aromatic hydrocarbons (naphthalene, phenanthrene and pyrene) from waste crude oil. The majority of isolated strains belonged to the genus Bacillus.

Bacteria↗
PubMed2002

The influence of autonomic neuropathy on hypotension during hemodialysis.

UNLABELLED: Many patients with chronic renal failure experience profound hypotension during hemodialysis. This phenomenon may be caused by hypovolemia, autonomic or cardiac dysfunction, vascular resistance defects or vasoactive substances such as nitric oxide or adrenomedullin. The aim of the study was to evaluate the influence of autonomic neuropathy on the occurrence of hypotension during hemodialysis. Fifty-three patients with chronic renal failure on maintenance hemodialysis underwent a standard battery of cardiovascular tests for the diagnosis of autonomic neuropathy. The study population was then divided into two groups, with (AN+) and without (AN-) autonomic neuropathy. Blood pressure (BP) was recorded before, during and after hemodialysis for 10 consecutive dialysis sessions and the mean value was calculated. RESULTS: Of the patients, 38% were AN+. During hemodialysis, systolic BP was lower in AN+ than in AN- patients at the third hour (110.0 +/- 17.5 vs 128.0 +/- 26.2; p = 0.049). Systolic BP reduction during hemodialysis was greater in AN+ than AN-patients (-21.2 +/- 10.9 vs -13.5 +/- 10.6% change, p = 0.013). CONCLUSION: The presence of autonomic neuropathy is associated with a more severe BP fall during hemodialysis. Routine evaluation of autonomic function may be helpful in defining patients at risk for dialysis-induced hypotension.

Adult↗
PubMed2001

Yield production, chemical composition, and functional properties of emulsifier H28 synthesized by Halomonas eurihalina strain H-28 in media containing various hydrocarbons.

Halomonas eurihalina strain H-28 is a moderately halophilic bacterium that produces an extracellular polysaccharide not only in media with glucose but also in media supplemented with hydrocarbons (n-tetradecane, n-hexadecane, n-octane, xylene, mineral light oil, mineral heavy oil, petrol, or crude oil). In this study we investigated yield production, chemical composition, viscosity, and emulsifying activity of exopolysaccharides (EPS) extracted from the different media used. The largest amounts of biopolymer were synthesized in media with glucose and n-hexadecane. Chemical composition varied with culture conditions; thus EPS from cultures grown in the presence of hydrocarbons had lower contents of carbohydrates and proteins than EPS from media with glucose. However, the percentages of uronic acids, acetyls, and sulfates were always higher than glucose EPS. Crude oil was the substrate most effectively emulsified. All EPS were capable of emulsifying crude oil more efficiently than the three control surfactants tested (Tween 20, Tween 80, and Triton X-100). All polymers gave low viscosity solutions. EPS H28 could be attractive for application in the oil industry and/or in bioremediation processes, bearing in mind not only its functional properties, but also the capacity of producer strain H-28 to grow in the presence of high salt concentrations and oil substrates.

Culture Media↗
PubMed2001

Long-term effect of bilateral ovariectomy on endothelial function in aortic rings of spontaneously hypertensive rats: role of nitric oxide.

Endothelial dysfunction associated with both menopause and hypertension could be one of the possible explanations for increased cardiovascular morbidity and mortality in hypertensive postmenopausal women. The aim of the present study was to investigate the long-term effect of menopause (bilateral ovariectomy) on endothelial function in isolated aortic rings of spontaneously hypertensive rats (SHR). Aortic rings were suspended in organ chambers filled with physiological salt solution (95% O2, 5% CO2, 37 degrees C), and isometric tension was measured. In studies designed to assess the tone-related release of nitric oxide (NO) from phenylephrine-precontracted aortic rings, we found that vasoconstriction induced by L-NAME was greater in aortic rings from sham-ovariectomized SHR (SHAM SHR) than in those obtained from ovariectomized SHR (OVX SHR). Concentration-related relaxant responses to superoxide dismutase were significantly greater in the SHAM SHR than in the OVX SHR. In contrast, receptor-mediated release of NO was not altered by ovariectomy, as deduced from acetylcholine (ACh) concentration-responses curves. Responses to the exogenous NO donor sodium nitroprusside (SNP) were also identical in both ovariectomized and sham-ovariectomized groups, ruling out differences in smooth muscle reactivity to NO. These results show that NO release is impaired in OVX SHR, an animal model of simultaneous hypertension and menopause.

Acetylcholine↗
PubMed2001

Early and delayed consolidation chemotherapy significantly improves the outcome of children with intermediate risk acute lymphoblastic leukemia. Final results of the prospective randomized PETHEMA ALL-89 TRIAL.

BACKGROUND AND OBJECTIVES: To evaluate the impact of early and delayed consolidation chemotherapy on the outcome of children with acute lymphoblastic leukemia (ALL) stratified according to risk groups. DESIGN AND METHODS: From 1989 to 1994, 195 children (< or = 15 years old) diagnosed as having ALL (ALL-L3 excluded) in 15 Spanish hospitals entered the prospective, randomized PETHEMA ALL-89 trial. Patients were stratified into low-risk (LR), intermediate-risk (IR) and high-risk (HR) groups according to their initial features and the rate of response to induction therapy. LR-ALL patients were randomized to receive or not early consolidation chemotherapy (C-1). After receiving C-1, IR patients were randomized to receive or not delayed consolidation chemotherapy (C-2). HR patients received C-1 and C-2 chemotherapy. Standard maintenance chemotherapy was administered to all patients for 2 years. High doses of intravenous methotrexate and 12 triple intrathecal doses were given as prophylaxis against central nervous system (CNS) disease. RESULTS: The mean (and standard deviation) age was 6 (4) years and 120 patients were males. Fourteen patients had early pre-B-ALL, 149 common or pre-B-ALL, and 32 T-ALL. Complete remission (CR) was attained in 189 patients (97%), 11 of whom (6%) had a slow response. Risk group stratification after CR was: LR 89, IR 50 and HR 56 patients (including a subset of 26 patients at very high risk). Ten-year event-free survival (EFS) and overall survival (OS) probabilities for the whole series were 58% (95% CI: 52-64%) and 69% (61-77), respectively, with a median follow-up of 8.7 years. Dividing the patients according to risk group, the 10-year EFS and OS probabilities in the LR group were 71% (63-79) and 86% (80-92), respectively; in the IR group 69% (57-81) and 76% (64-88), respectively, and in the HR group 30% (18-42) and 44% (32-57), respectively. For LR patients receiving C-1, EFS and OS were 79% (57-92) and 90% (82-98), respectively, versus 62% (48-76) and 66% (51-81) in patients not receiving C-1 (p= 0.06). For IR patients, EFS and OS were significantly improved in those receiving early and delayed consolidation (EFS 87% (74-88) vs. 52% (41-70), and OS 92% (87-97) vs. 61% (51-71)(p=0.036). Prognostic factors for EFS identified in multivariable analyses were: age >10 years in the LR group (OR 3.5, 95% CI 1.3-9.5, p=0.01), and treatment with C-2 in IR patients (OR 5.0, 95% CI 1.4-17.8, p=0.01). The CNS relapse rate was 4% for all the series (including the HR subset). Tolerance to treatment was good. INTERPRETATION AND CONCLUSIONS: In this study, early consolidation seemed to improve the prognosis of children with LR-ALL, but differences in EFS were not significant. Delayed consolidation had a favorable influence on the outcome of IR-ALL. CNS preventive treatment without cranial irradiation was effective in all the groups of ALL patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Antibiotic resistance patterns of coliforms isolated from six protected wetlands in the southeast of Spain.

Coliforms and thermotolerant coliforms were isolated from six protected lakes in the Antequera area of Spain in order to assess the sanitary quality of these wetlands. The thermotolerant coliform group consisted of several bacterial genera with a wide spectrum of antibiotic resistance. Resistance among Escherichia coli strains was correlated with the origin of the sample and three homogeneous groups of wetlands were distinguished. One of them, which corresponded to wetlands where faecal indicators were indigenous, exhibited no correlation between these bacteria and faecal pollution. Non-coli strains showed a similar range of antibiotic susceptibility for this group. In the other two groups a faecal pollution was detected and antibiotic resistance for E. coli strains established the origin of pollution.

Animals↗
PubMed2000

Monoclonal antibodies to human apolipoproteins: application to the study of high density lipoprotein subpopulations.

We produced, selected and cloned hybridomas that secrete monoclonal antibodies against human apolipoprotein (apo) A-I. All of the antibodies corresponded to the IgG(1) subclass and were named 1C11, 2B4, 2C10, 7C5, 8A4 and 8A5. The antibodies were characterized by their reactivity with whole lipoproteins, apolipoproteins, synthetic peptides and fragments generated by cleavage of the apo A-I. Three of the monoclonal antibodies studied (2B4, 2C10 and 7C5) were similarly inhibited by an amino-terminal peptide (amino acid sequence 1-20) of apo A-I, whereas antibodies 1C11, 8A4 and 8A5 had no reaction. Other results show that monoclonal antibody 1C11 recognizes an epitope located between amino acids 135-148. We evaluated the monoclonal antibody 8A4 against different HDL subpopulations by competitive displacement analysis and it showed a similar reactivity with the HDL particles: LpA-I and LpA-I:A-II. This antibody was used to standardize a sandwich ELISA to quantitate LpA-I in plasma. We conclude that these monoclonal antibodies are relevant for the study of apo A-I epitope expression and for quantitating apo A-I containing lipoparticles.

Animals↗
PubMed2000

[Lipoprotein particles LpA-I, LpA-I: A-II and LpB in coronary artery disease].

BACKGROUND: High density lipoproteins are an heterogeneous population of particles. Two main subpopulations have been identified, one contains Apo A-I and Apo A-II and is denominated LpA-I:A-II and another one contains only Apo A-I and is denominated LpA-I. AIM: To measure the concentrations of these particles in patients with stable coronary artery disease. PATIENTS AND METHODS: Serum lipids, A-I and B apolipoproteins, LpA-I, LpA-I:A-II and LpB particles were measured in 73 men aged 33 to 82 years with angiographically documented coronary artery disease (CAD) and 33 control subjects aged 39 to 76 years. LpA-I, LpA-I:A-II and LpB were measured by a noncompetitive enzyme linked immunoassay using previously characterized monoclonal antibodies against ApoA-I, ApoA-II and apoB. RESULTS: Patients with CAD had significantly higher mean levels of LDL cholesterol than the control group (p = 0.038). The mean concentration of LpA-I particles in patients with CAD was significantly lower (p = 0.031) than in control subjects, while the concentration of LpA-I:A-II particles was significantly higher (p = 0.016). The percentage of coronary stenosis correlated negatively with LpA-I and positively with LpA-I:A-II. The best relative risk (RR) indicator in these patients was LDL-cholesterol. The relative risk increases 2.5 fold when LpA-I falls below the cut-off level. Likewise, the relative risk increases 3-fold when LpA-I:A-II raises over the cut-off level. CONCLUSIONS: Our findings indicate that the quantification of LpA-I and LpA-I:A-II particles might allow a more accurate evaluation of the CAD risk than HDL cholesterol. LpA-I might represent the antiatherogenic fraction of HDL.

Adult↗
PubMed2000

[Langerhans cell histiocytosis of the temporal bone].

Eosinophilic granuloma (EG) is a localized, benign form of Langerhans' cell histiocytosis. It is the least severe of the histiocytosis syndromes and characterized by lytic lesions of one or more bones. Temporal bone lesions usually occur in association with multifocal disease, but isolated lesions may occur in either the mastoid bone alone or in the entire temporal bone affecting other sites in the body. Two cases of EG of the temporal bone are reported and the literature is reviewed.

Adolescent↗
PubMed1999

Spectrum of CFTR mutations in the Middle North of Spain and identification of a novel mutation (1341G-->A). Mutation in brief no. 252. Online.

We have analyzed 39 unrelated cystic fibrosis (CF) families by denaturing gradient gel electrophoresis (DGGE) and direct sequencing in order to determine the spectrum of CF mutations in our population. This approach has allowed us to detect 72 out of the 78 CF chromosomes (92.3%). The DF508 mutation was found to be present in 51/78 (65.4%) CF chromosomes, in accordance with the predicted Northwest-Southeast gradient within the European population. Another 14 known mutations, and the novel 1341G-->A mutation were identified. Nine out of fifteen non DF508 mutations were present in a single chromosome. The 1341G-->A mutation, found in 2 unrelated patients, is a new mutation associated to severe phenotype, causing pancreatic insufficiency and chronic lung infections. Our data suggest a different distribution of non-DF508 mutations in our population when compared with previous studies carried out in Spanish CF families. Six out of the 14 non-F508 in our study were not present in a recent study carried out in 640 Spanish families with CE These six mutations account for 29.6% non DF508 chromosomes in our sample.

Cystic Fibrosis↗