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Biomedical subjects

M Ruano

Publications and source records attributed to M Ruano.

At least 19 recordsLinked to original sources
PubMed2006

Losartan improves resistance artery lesions and prevents CTGF and TGF-beta production in mild hypertensive patients.

Although structural and functional changes of resistance arteries have been proposed to participate in arterial hypertension (HTA) outcome, not all therapies may correct these alterations, even if they normalize the blood pressure (BP). The aim of this study was to investigate the mechanisms of the protection afforded by the angiotensin receptor antagonist losartan in resistance arteries from patients with essential HTA. In all, 22 untreated hypertensive patients were randomized to receive losartan or amlodipine for 1 year and the morphological characteristics of resistance vessels from subcutaneous biopsies were evaluated. Protein expression of connective tissue growth factor (CTGF), transforming growth factor beta (TGF-beta), and collagens III and IV was detected by immunohistochemistry. In comparison with normotensive subjects, resistance arteries from hypertensive patients showed a significant media:lumen (M/L) ratio increment and a higher protein expression of CTGF, TGF-beta, and collagens. After 1 year of treatment, both losartan and amlodipine similarly controlled BP. However, M/L only decreased in patients under losartan treatment, whereas in the amlodipine-treated group this ratio continued to increase significantly. The administration of losartan prevented significant increments in CTGF, TGF-beta, and collagens in resistance arteries. By contrast, amlodipine-treated patients showed a higher vascular CTGF, TGF-beta, and collagen IV staining than before treatment. Our results show that the administration of losartan, but not amlodipine, to hypertensive patients improves structural abnormalities and prevents the production of CTGF and TGF-beta in small arteries, despite similar BP lowering. These data may explain the molecular mechanisms of the better vascular protection afforded by drugs interfering with the renin-angiotensin system.

Adult↗
PubMed2006

HOMA, QUICKI and MFfm to measure insulin resistance in morbid obesity.

BACKGROUND: The relationship between morbid obesity (MO) and insulin resistance (IR) has been widely demonstrated. The euglycemic-hyperglycemic clamp method for diagnosis of IR is neither practical nor cost-effective for population-based studies. However, the application of mathematical models (HOMA, QUICKI and Mf(fm) indices) can be useful. METHODS: The data from 171 patients were retrospectively evaluated. We recorded general anthropometric parameters and the basal levels of glucose, triglycerides and insulin and calculated the metabolic indexes both before surgery (Capella gastric bypass) and 6, 12, 24, 36 and 48 months after the operation. RESULTS: Before surgery, patients could be classified according to their waist-hip ratio (WHR) into 2 groups. Group A (n = 131, 108 females and 23 males) with WHR values 1.10 +/- 0.1 SD for males and 0.94 +/- 0.1 for females (central obesity); and Group B (n = 40, 34 females and 6 males) with WHR values 0.90 +/- 0.1 for males and 0.84 +/- 0.1 for females (peripheral obesity). Group A patients showed elevated serum levels of glucose, triglycerides and insulin and high values of the HOMA index with low values of QUICKI and Mf(fm). Group B patients showed lower levels of glucose, triglycerides, insulin and HOMA index and higher values of QUICKI and Mf(fm). These abnormal levels began to decrease 6 months after bypass and the QUICKI and Mf(fm) began to increase. CONCLUSIONS: The high baseline levels of insulin and the high prevalence of hypertension, diabetes or both conditions in patients with central obesity confirm that they suffer a metabolic syndrome, Meanwhile, patients with peripheral obesity with lower levels of chemical parameters and of the metabolic indices suffer peripheral resistance against insulin. Clinical application of these mathematical indices can be useful in patients with MO; they are easily performed and lack the high costs and risks associated with the clamp technique.

Adolescent↗
PubMed2005

Morbid obesity, hypertensive disease and the renin-angiotensin-aldosterone axis.

BACKGROUND: Resistance to insulin and secondary hyperinsulinemia seem to be the putative link between morbid obesity (MO) and hypertensive disease (HD). Adipose tissue can secrete leptin and angiotensinogen, among other substances. Leptin activates the sympathetic nervous system, leading to HD. Angiotensinogen is a substrate for renin, therefore taking part in the renin-angiotensin-aldosterone axis and the regulation of blood pressure. In MO, both hypertrophy and hyperplasia of the adipocytes lead to an increase in the secretion of both substances, leading to loss of the equilibrium between the levels of both hormones. The aim of the present study was to evaluate these abnormalities and their potential reversibility following bariatric surgery. METHODS: Data from 100 patients with MO was retrospectively evaluated. Anthropometric data, the plasma renin activity (PRA), plasma levels of aldosterone, ACE, potassium and sodium were collected both prior to surgery and 6, 12, 24 and 36 months after surgery. RESULTS: The waist-hip ratio (WHR) before surgery allowed classification of our patients in two groups: central obesity (WHR > or =0.90 in men and > or =0.85 in women); peripheral obesity (WHR <0.90 in men and <0.85 in women). In patients with central obesity, high levels of PRA, aldosterone and ACE with sodium retention and potassium loss and high insulin levels, were found. These changes were not found in patients with peripheral obesity. After gastric bypass, these abnormalities tended to disappear, mainly in the first 6 months. CONCLUSIONS: The reduction of BMI and WHR after gastric bypass confirmed this operation to be effective against MO. The high basal levels of insulin and the high rate of HD and diabetes in patients with central obesity seem to indicate that they suffer a metabolic syndrome with significant hormonal imbalances and sodium retention. Patients with peripheral obesity only showed a peripheral resistance against insulin, probably with a shorter duration of the hormonal action, but they did not show hormonal abnormalities or sodium retention. After gastric bypass these abnormal hormone levels tended to normalize.

Adolescent↗
PubMed2004

Hypocomplementaemia as an immunological marker of morbidity and mortality in patients with primary Sjogren's syndrome.

OBJECTIVE: To analyse the prevalence and clinical significance of hypocomplementaemia in a large series of patients with primary Sjogren's syndrome (SS), focusing on the association of low complement levels with clinical manifestations, immunological features, lymphoproliferative disorders and mortality. METHODS: Complement determinations (C3 and C4 levels, CH50 activity) were made in 336 consecutive patients with primary SS (313 women and 23 men, mean age 58.5 yr). We also analysed complement levels in 46 patients with SS associated with hepatitis C virus (HCV) infection and 184 with HCV-related cryoglobulinaemia as control groups. RESULTS: Hypocomplementaemia was detected in 81 (24%) of patients with primary SS, low CH50 being detected in 51 (15%), low C3 values in 42 (12%) and low C4 values in 39 (12%). In the multivariate analysis, patients with low C4 levels showed a higher prevalence of peripheral neuropathy, cutaneous vasculitis, RF, cryoglobulins and lymphoma compared with those with normal C4 levels. The analysis of the 218 SS patients followed prospectively since 1994 showed a lower probability of survival in patients with hypocomplementaemia (with low C3, C4 or CH50 levels) at protocol entry. SS-HCV patients presented a higher frequency of hypocomplementaemia than patients with primary SS (76 vs 24%, P<0.001); nine (20%) of these patients had persistent, unquantifiable complement levels. CONCLUSION: Hypocomplementaemia is closely associated with systemic expression and adverse outcomes (lymphoma development and death) in patients with primary SS. Our results support the inclusion of complement determination at diagnosis as a predictor of the outcome of patients with primary SS and its routine determination in the clinical follow-up.

Aged↗
PubMed2004

Morbid obesity and gastric bypass surgery: biochemical profile.

BACKGROUND: Morbid obesity (MO) and the pathologies associated with it constitute an important public health problem, accounting for 7% of the health expenditure in industrialized countries. An important percentage of this expense is attributed to the different biochemical tests performed in these patients, who suffer from several metabolic derangements. We evaluated the basic biochemical abnormalities in MO patients and their reversibility by weight loss after gastric bypass, to standardize the surveillance of the different metabolic abnormalities in obese patients. METHODS: By a retrospective analysis on 125 patients operated in our hospital, we evaluated anthropometric and biochemical data before and 1, 3, 6, 12 and 24 months after gastric bypass. RESULTS: Preoperatively hyperinsulinemia, hyperglycemia, dyslipidemia and hypertensive disease were present, and began to improve 1 and 3 months after surgery (although not significantly) and significantly at 6, 12 and 24 months after it. We also observed deficient protein nutrition and a deficiency of micronutrients both before bypass and during the follow-up. CONCLUSION: After gastric bypass, a marked decrease in insulin occurred, with normalization of blood pressure and the biochemical parameters associated with the metabolic syndrome. We propose a biochemical follow-up protocol for MO patients.

Adolescent↗
PubMed2003

Summary of the 2001-02 Pennsylvania H7N2 low pathogenicity avian influenza outbreak in meat type chickens.

H7N2 low-pathogenicity (LP) avian influenza (AI) virus was isolated from chickens submitted to the Pennsylvania Animal Diagnostic Laboratory System on December 4 and 5, 2001. The cases were from two broiler breeder flocks in central Pennsylvania that had clinical signs of an acute, rapidly spreading respiratory disease. Seroconversion to AI virus was detected on follow-up sampling. Subsequently, H7N2 LPAI virus was isolated in five different broiler flock cases submitted between December 14, 2001, and January 3, 2002. Clinical signs and lesions in broilers, when present, were compatible with multicausal respiratory disease. With the exception of one broiler flock that was processed, birds from all of the virus positive flocks were euthanatized in-house within 11 days of the original case submission date. Increased surveillance of poultry flocks within 10-mile radius zones centered at the foci of the positive farms continued until March 1, 2002. No additional cases were detected.

Animals↗
PubMed2001

Topographical characterization and surface force spectroscopy of the photochemical lignin model compound.

By combining the results from atomic force microscopy (AFM) and environmental scanning electron microscopy (ESEM), herein we investigate properties of photochemical lignin model compounds. We provide evidence that photochemical lignin forms random, probably non-functional structures. The topography of such structures is explored using ESEM. Non-functionality of such structures is proved by AFM and atomic force spectroscopy experiments wherein the photochemical lignin functionalized tip is approached to the substrate covered with photochemical lignin. There was no evidence of existence of any kind of host-guest interaction during the approach/retraction experiments. These results provide evidence for our previously stated hypothesis that photochemical lignin polymerization may be one of the degrading effects of UV radiation to the plant cell.

Dimerization↗
PubMed2001

Reaction of vinyl epoxides with palladium-switchable bisnucleophiles: synthesis of carbocycles.

The selective activation of substrates I, potential bisnucleophiles, was achieved by using different palladium catalysts. The synthetic potential of this strategy has been demonstrated in the regiodivergent synthesis of carbocycles from substrates of type I, bearing malonate-type pronucleophiles and an alkenyl stannane, with vinyl epoxides. A selective palladium-catalyzed reaction of I with the vinyl epoxide gives rise to an allylic alcohol, which, after activation as a carbonate, led to the cyclization product by a second palladium-catalyzed reaction. The transmetalation process is favored with palladium-catalysts without phosphines or arsines as the ligands. On the other hand, the use of palladium complexes with PPh3 as the ligand inhibits the transmetalation pathway and promotes the nucleophilic attack of the malonate-type anions on the intermediate (eta 3-allyl)-palladium complexes.

Journal Article↗
PubMed2001

Effects of unfractionated and low molecular weight heparins on plasma levels of hemostatic factors in patients with acute coronary syndromes.

BACKGROUND AND OBJECTIVES: Unfractionated heparin (UFH) and enoxaparin (low molecular weight heparin) constitute fundamental therapies in the treatment of patients with acute coronary syndrome (ACS). Since enoxaparin appears to offer clinical advantages over UFH in managing ACS, markers of thrombin generation, endothelial function and acute phase response could manifest different responses to UFH or enoxaparin. The purpose of the present study was to investigate the effect that treatment with either UFH or enoxaparin has on plasma hemostatic markers in 24 patients with ACS. DESIGN AND METHODS: The patients were randomized to receive 5,000 IU intravenous bolus and continuous infusion of 18 IU/Kg/h UFH (n=11) or 1 mg/kg/12h subcutaneous enoxaparin (n=13). The plasma levels of fibrinogen (Fg), prothrombin fragment 1+2 (F1+2), thrombin antithrombin complex (TAT), von Willebrand factor (vWF), tissue factor (TF) and tissue factor pathway inhibitor (TFPI) were assayed at admission and 6, 12, 24 and 48 hours after heparin treatment. RESULTS: Upon admission, UFH and enoxaparin patients showed a significant increase in all the hemostatic parameters measured with respect to the levels in the control subjects. In comparison with the baseline levels of the UFH- and enoxaparin-treated patients, Fg showed a significant increase at 48 h and TFPI at 6, 12 and 24 hours. However, at 48 hours TFPI levels were not significantly higher than the basal values. There were no significant changes in F1+2, TAT, vWF or TF. INTERPRETATION AND CONCLUSIONS: Markers of thrombin generation, endothelial function and acute-phase reactants manifest a similar response to UFH and enoxaparin. An increase in thrombin generation may be a result of persistently activated inflammatory and endothelial processes, despite UFH and enoxaparin treatment.

Acute Disease↗
PubMed1999

Elevated high molecular weight fibrinogen in plasma is predictive of coronary ischemic events after acute myocardial infarction.

This study investigates the association between the concentration and function of plasma fibrinogen molecules measured at the time of hospital admission in patients with acute myocardial infarction (AMI), with reference to the risk of new coronary ischemic events during a three-day follow-up period of. Before starting fibrinolytic and anticoagulant treatment plasma fibrinogen, high molecular weight fibrinogen (HMW-fibrinogen), fibrin formation rate (FbFR) and phosphorous content in fibrinogen were determined in 90 AMI patients. During a three-day follow-up period 12 patients suffered new ischemic events. The 12 patients with coronary ischemia had higher concentrations of plasma fibrinogen (312+/-23 vs. 270+/-73 mg/dl, p<0.05) and HMW-fibrinogen (246+/-35 vs. 189+/-23 mg/dl, p<0.001) and a higher FbFR (65+/-30 vs. 40+/-25, p<0.001) than patients without these events. No association was found between the phosphorous content in fibrinogen and new coronary ischemic events. We conclude that after myocardial infarction an elevated plasma level of HMW-fibrinogen and a high FbFR value at the time of hospital admission are associated with new coronary ischemic events during a three-day follow-up period.

Aged↗
PubMed1996

[Validity of the protocol for evaluating the inappropriate use of hospitalization].

BACKGROUND: The study was carried out in order to assess the inter-observer reliability and validity in respect of clinical appraisal given by the Appropriateness Evaluation Protocol (AEP), in the context of the Spanish Public Hospital System. MATERIAL AND METHOD: In order to assess the reliability a total of 614 hospital stays chosen at random from 56 hospital admissions were independently analysed by three reviewers (two doctors and one nurse). In order to assess the validity, the findings obtained by the nurse were compared with the majority opinion given by the 7 hospital specialists in respect of each of hospital stays under evaluation. As part of the analytical procedure, indices for observed agreement, and specific agreement were calculated, as well as the Kappa statistic, all forming of various random samples of 614 hospital stays. In order to assess the predictive validity of the AEP, its sensitivity, specificity and predictive values were all measured against the majority clinical judgement. RESULTS: The study exhibited a high degree of inter-observer reliability (specific agreement > 64%, kappa > 0.75) and a reasonable validity in comparison with the consensus of opinions formed by a least 4 or 5 of its 7 clinical reviewers (specific agreement > 61%, kappa > 0.64), these values decreasing notably when the consensus of 6 or 7 of the reviewers was required. The AEP revealed a high degree of sensitivity and a low degree of specificity in comparison with the majority clinical assessment, thus minimising the occurrence of false results when the stay was regarded as appropriate, and producing false negatives (appropriate hospital stays regarded as inappropriate) varying in degree from moderate to very high. CONCLUSIONS: The results showing high reliability and moderate validity regarding clinical assessment shows the AEP to be a useful instrument in the sifting-out of inappropriate use of hospitalisation, although they do not allow a definitive judgement to be made concerning the efficiency of hospital services nor judgements regarding individual cases.

Evaluation Studies as Topic↗
PubMed1993

Studies on the functionality of newly synthesized fibrinogen after treatment of acute myocardial infarction with streptokinase, increase in the rate of fibrinopeptide release.

In 15 patients with acute myocardial infarction who received 1,500,000 U of streptokinase, the gradual appearance of newly synthesized fibrinogen and the fibrinopeptide release during the first 35 h after SK treatment were evaluated. At 5 h the fibrinogen circulating in plasma was observed as the high molecular weight fraction (HMW-Fg). The concentration of HMW-Fg increased continuously, and at 20 h reached values higher than those obtained from normal plasma. HMW-Fg represented about 95% of the total fibrinogen during the first 35 h. The degree of phosphorylation of patient fibrinogen increased from 30% before treatment to 65% during the first 5 h, and then slowly declined to 50% at 35 h. The early rates of fibrinopeptide A (FPA) and phosphorylated fibrinopeptide A (FPAp) release are higher in patient fibrinogen than in isolated normal HMW-Fg and normal fibrinogen after thrombin addition. The early rate of fibrinopeptide B (FPB) release is the same for the three fibrinogen groups. However, the late rate of FPB release is higher in patient fibrinogen than in normal HMW-Fg and normal fibrinogen. Therefore, the newly synthesized fibrinogen clots faster than fibrinogen in the normal steady state. In two of the 15 patients who had occluded coronary arteries after SK treatment the HMW-Fg and FPAp levels increased as compared with the 13 patients who had patent coronary arteries. These results provide some support for the idea that an increased synthesis of fibrinogen in circulation may result in a procoagulant tendency. If this is so, the HMW-Fg and FPAp content may serve as a risk index for thrombosis.

Adult↗
PubMed1993

[Standard formulas of parenteral nutrition. A study of their use in a general hospital].

The goal of the study was to evaluate the use of parenteral nutrition formulas with standardized g. of nitrogen, carbohydrates and lipids, and to analyze whether the nutritional requirements of the patients treated in our hospital were covered by said formulas or whether it was necessary to change and/or standardize a new formula. To do so, a review was made of 5.646 parental nutrition mixtures prepared in the Pharmacy Service and patterned by the Nutrition Service from April, 1991, to May, 1992, for 308 adult patients. The distribution of the mixtures by services, diagnoses and the frequency of the different standard formulas were studied, comparing standard formula frequency with that of non-standard formulas. Findings showed that 41.9% of nutrition mixtures were patterned in surgery, and the most common diagnosis, cancer, appeared in 24%. Of the mixtures, 67.6% were preestablished formulas, and 32.4% were non-standard formulas. The order of frequency among standard formulas was: basic standard formulas, stress formulas, initial formulas, peripheral formulas, hemodialysis formulas and low-volume formulas. All covered the nutritional needs of a large share of the patients for the different pathologies in which they were indicated. Nevertheless the question of designing a new formula to cover a greater number of situations was raised. Protocolization should take place rationally, to meet the hospital's most frequent pathologies, and effectiveness should be evaluated after tracking and checking each patient.

Adult↗
PubMed1990

Hypercoagulable state after thrombolytic therapy in patients with acute myocardial infarction (AMI) treated with streptokinase.

Fibrinogen activity was studied in 70 patients with AMI who were treated with an intravenous infusion of SK (800,000 U/30 min or 1.5 mill U/60 min). Patients received a continuous infusion of heparin after thrombolytic therapy was completed. 800,000 U and 1.5 mill U SK recanalized infarct-related arteries at a rate of 78%. Early re-infarction occurred in 6% in each group. Upon admission to the hospital patients showed a hypercoagulable state that may be related to an elevated level of fibrinogen and HMW fibrinogen (70.5 +/- 2 vs 65 +/- 2% in patient and normal plasmas, respectively) that changed to a transitory hypercoagulable state indicated by decreased fibrinogen levels after SK treatment. Forty-eight hours after SK, a new fibrinogen hyperfunction, related to an increase in fibrinogen level and especially HMW synthesized fibrinogen (82 +/- 1 or 81 +/- 1%, 800,000 and 1.5 mill U SK, respectively) was observed, which was neutralized by heparin therapy (1,660 U/h with continuous infusion). The elevated levels of fibrinogen (363 +/- 21 vs 240 +/- 8 mg/dl in patient and normal plasmas, respectively) and HMW fibrinogen (70 +/- 3% with both SK hypercoagulable state that is not neutralized by the heparin dose were compared with those whose arteries recanalized. The former group had a higher concentration of fibrinogen (197 +/- 31 vs 147 +/- 18 mg/dl), HMW fibrinogen (78 +/- 0.5 vs 74 +/- 0.3%, respectively), and FPA (130 +/- 3 vs 6 +/- 4 pmol/ml) and more extensive fibrin gel formation kinetics (gelation rate 3.3 +/- 1.4 vs 1.1 +/- 0.2 OD/s x 10(-4), respectively) than the second group. The hypercoagulable state found in patients with acute myocardial infarction undergoing thrombolytic therapy may be related mainly to the progression of HMW fibrinogen and fibrinogen levels.

Adult↗