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Biomedical subjects

J Gómez

Publications and source records attributed to J Gómez.

At least 19 recordsLinked to original sources
PubMed2002

Prior aspirin use in unstable angina patients with modified plasma inflammatory markers and endothelial nitric oxide synthase in neutrophils.

BACKGROUND: Prior use of aspirin in patients with acute coronary syndrome has been associated with a lower incidence of acute myocardial infarction. The aim of this study was to explore if prior aspirin therapy in unstable angina (UA) patients could modify systemic inflammatory markers such as interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha) and intercellular adhesion molecule-1 (ICAM-1) and the expression of endothelial nitric oxide synthase (eNOS) in neutrophils. MATERIALS AND METHODS: Unstable angina was defined as transient S-T segment changes without significant increases in CK and CK-MB. We studied 50 consecutive patients admitted to hospital within 24 h after the onset of chest pain. The number of patients with prior aspirin was significantly higher (n = 32) than those not taking aspirin (n = 18) on admission. RESULTS: Plasma levels of IL-6 and ICAM-1 were significantly increased in the UA patients when compared with the healthy control volunteers (n = 20) used as a reference for normal values. Plasma levels of both IL-6 and ICAM-1 were reduced in patients taking aspirin. There were no differences in the plasma levels of TNF-alpha between the UA patients and the control volunteers. The eNOS protein expression was also higher in neutrophils from the UA patients taking aspirin than in those not taking aspirin. CONCLUSION: Patients taking aspirin before UA showed a lower systemic inflammatory response and higher eNOS protein expression in their neutrophils

Aged↗
PubMed2002

Relationship between risperidone and 9-hydroxy-risperidone plasma concentrations and CYP2D6 enzyme activity in psychiatric patients.

The implication of cytochrome P450 CYP2D6 enzyme activity in the metabolism of the antipsychotic drug risperidone has been reported in vitro and in studies of healthy volunteers. Around 7 % of Caucasians have inherited impaired capacity of this enzyme (poor metabolisers). These subjects might be prone to higher plasma concentrations of risperidone. The aim of the study was to determine the relationship between the debrisoquine metabolic ratio (MR), a marker of CYP2D6 enzyme activity, and risperidone plasma levels in psychiatric patients. A population of 40 Spanish and Hungarian schizophrenic patients was studied. The possible inhibition of CYP2D6 enzyme was also evaluated in a subgroup of patients co-medicated with inhibitors of CYP2D6. The risperidone/9-hydroxy-risperidone ratio correlated significantly with debrisoquine MR (p < 0.001). In patients co-medicated with strong inhibitors of CYP2D6, the plasma levels of risperidone (p < 0.05) and debrisoquine MR (p < 0.01) and risperidone/9-hydroxy-risperidone ratio were higher compared to patients with monotherapy. According to the present data, the evaluation of the risperidone/9-hydroxy-risperidone ratio may reflect the actual enzyme activity of CYP2D6. Therefore, the use of this ratio may help to assess potential pharmacokinetic interactions and to improve risperidone treatment.

Adult↗
PubMed2002

[Influence of the application of a rational, consensual protocol on the use of antibiotics in a general hospital].

A large increase in the use of wide-spectrum antibiotics has occurred in Spain. The objective of our study was to evaluate the influence of applying protocols for the use of such antibiotics. A prospective, observational study was carried out based on the information provided by the pharmacy service about prescriptions of ceftriaxone, cefotaxime, ceftazidime, imipenem and ciprofloxacin at the single-dosing department of the hospital. Two groups were included in the study: 1) control group (October-December 1995), which did not take into account the protocols for antibiotic treatment; and 2) the study group, during the same months in 1996, which took into account the consensual protocols. The criteria for the type of patient, infection and outcome, and type of antibiotic treatment were evaluated according to the rules of the international literature for this type of study. The baseline characteristics of both groups of patients were similar. Following the application of the protocol, a decrease in the use of antibiotics was observed (108 cases in group 2 vs. 207 cases in group 1); an increase in the appropriateness of treatment (50.72% in group vs. 77.57% in group 2); an increase in the cure rate (78.26% in group 1 vs. 91.67% in group 2); and a decrease of 5.01 days in the length of hospital stay (22.99 days in group 1 vs. 17.98 days in group 2), which was statistically significant, and thus led to a savings of 2073.74 Euros per cured patient. The application and adherence to a consensual protocol is a beneficial method of using antibiotics since it improves the quality of their use and makes it more cost-effective.

Anti-Bacterial Agents↗
PubMed2002

[Pseudomonas aeruginosa bacteremia: clinical and epidemiological patterns and treatment].

Pseudomonas aeruginosa bacteremia has the highest mortality among Gram-negative infections. We studied its clinical and epidemiological patterns in order to achieve an early and accurate diagnosis and treatment. We prospectively studied 211 cases of P. aeruginosa bacteremia admitted to our hospital from 1991 to 1998. All patients had at least one positive blood culture for P. aeruginosa and clinical symptoms of bacteremia. The prognosis of the underlying disease, past illnesses, foci location, initial clinical status, type of bacteremia, complications, and the type of antibiotic treatment were analyzed. Clinical and microbiological controls were carried out at baseline, at the end of the treatment period, and 1 month later. Of the 211 cases, 73% were men with a mean age of 56.5 years. Overall, 45.5% were hospitalized in the ICU, 28% in the surgical ward, and 26% in the medical service, with a mean length of stay of 40.4 days. As risk factors we identified a length of stay more than 14 days (76.7%), previous manipulations (87.6%), and surgery (44.5%). A total of 43.1% had had an infection in the last 6 weeks, and 46.4% were treated with antibiotics, usually broad-spectrum antibiotics without activity against P. aeruginosa. The most frequent underlying diseases were neoplasia (25.5%), postsurgical cardiopathy (24.1%), nephrosis (22.7%), chronic obstructive pulmonary disease (17.5%) and diabetes (13.2%). The most frequent foci were pulmonary (29.3%), urinary (21.8%), and undetermined (38.3%). The mortality rate was 27.9% and was considered related to P. aeruginosa bacteremia in 76.2% of the cases. The antibiotic treatment was considered adequate in 89% of the cases. It was concluded that knowledge of the clinical and epidemiological factors of patients with P. aeruginosa bacteremia may help to optimize its management and to reduce its morbidity and mortality.

Bacteremia↗
PubMed2001

Luminescent alkynyl platinum-cadmium complexes: structural characterization of an unusual decanuclear cluster.

The reaction of (NBu(4))(2)[Pt(C triple bond CPh)(4)] with Cd(ClO(4))(2).6H(2)O in a 1:1 molar ratio yields a white solid [PtCd(C triple bond CPh)(4)](n) 1 (75% yield) together with yellow crystals of a very unusual decanuclear platinum-cadmium cluster [Pt(4)Cd(6)(C triple bond CPh)(4)(mu-C triple bond CPh)(12)(mu(3)-OH)(4)] 2 in low yield. Slow diffusion of acetonic solutions of the starting materials under aerobic conditions only produces crystals of 2 which have been shown by an X-ray analysis to be composed of a big hexanuclear cation [Cd(6)(mu(3)-OH)(4)](8+) and four [Pt(C triple bond CPh)(4)](2-) anions, held together by Pt.Cd and pi.Cd acetylide interactions. On the other hand, treatment of the insoluble product 1 with 1 equiv of NBu(4)X yields tetranuclear mixed-metal soluble complexes (NBu(4))(2)[[Pt(mu-C triple bond CPh)(4)](2)(CdX)(2)] (X = Cl A, Br 3, CN 4), which contain two platinate fragments connected by two CdX units through Pt.Cd and mainly Cd.C(alpha) interactions. All complexes are strongly emissive in the solid state at room temperature.

Journal Article↗
PubMed2001

Results of a simple intercomparison of natural radioactivity measurements using a 'blue concrete' sample.

A simple intercomparison of natural radioactivity and radon emanation factor measurements co-ordinated by the Medical Physics Department of the University of Cantabria UC, Spain, has been carried out during 1998 in the framework of the EU Concerted Action ERRICCA (European Research into Radon in Construction Concerted Action). All the measurements have been made on a 'blue concrete' sample kindly donated by Dr G. Akerblom from the Swedish Radiation Protection Institute. In addition to UC, two other participant laboratories, STUK from Finland and ZVD from the Republic of Slovenia, have contributed to the development of the intercomparison exercise. Considering the uncertainties of the measurements, a good agreement between the results obtained by the three participating laboratories has been ascertained. However, in accordance with experimental results obtained by other authors, data reported by UC show a significant decrease of the radon emanation factor as moisture content of the sample decreases below 5% (per weight).

Construction Materials↗
PubMed2001

Expression of an endothelial-type nitric oxide synthase isoform in human neutrophils: modification by tumor necrosis factor-alpha and during acute myocardial infarction.

OBJECTIVES: The purpose of this study was to determine whether human neutrophils express an endothelial-type nitric oxide synthase (eNOS), and to study the effect of tumor necrosis factor-alpha (TNF-alpha) on its expression. BACKGROUND: Several studies have demonstrated the presence of a constitutively expressed nitric oxide svnthase (NOS) in neutrophils. Cardiovascular disease is characterized by increased levels of plasma TNF-alpha, a cytokine that has demonstrated eNOS messenger ribonucleic acid (mRNA) destabilization in cultured endothelial cells. METHODS: Neutrophils were obtained from healthy volunteers and from patients with acute myocardial infarction (AMI). RESULTS: Human neutrophils express eNOS mRNA and eNOS protein. Stimulation of neutrophils with TNF-alpha decreased eNOS protein expression by reducing eNOS mRNA stabilization. In the present study, we also show that the cytosol of human neutrophils contains proteins that bind to a specific region within the 3'-untranslated region (3'-UTR) of eNOS mRNA. Tumor necrosis factor-alpha increased the binding of the cytosolic proteins to the 3'-UTR of eNOS mRNA. Simvastatin reduced the TNF-alpha-related binding activity of neutrophil cytosolic proteins to eNOS mRNA, which was associated with its protective effect on eNOS protein expression. The in vivo reproduction of the in vitro findings was performed in neutrophils obtained from patients with AMI and showed a diminished expression of eNOS protein, which was associated with increased binding of the cytosolic proteins. CONCLUSIONS: These observations demonstrate that human neutrophils express eNOS, which is downregulated by TNF-alpha and during AMI. This effect is associated with increased binding of neutrophil cytosolic proteins to the 3'-UTR of eNOS mRNA.

Adult↗
PubMed2001

Application of capillary zone electrophoresis with off-line solid-phase extraction to in vitro metabolism studies of antifungals.

A simple and robust solid-phase extraction (SPE) procedure for the cleanup and sample preconcentration of antifungals (ketoconazole, clotrimazole, itraconazole, fluconazole, and voriconazole) and their metabolites after incubation with human liver microsomes, as well as a simplified capillary zone electrophoresis (CZE) method for their rapid analysis, have been developed to determine the stability of these compounds in in vitro samples. Three different sample pretreatment procedures using SPE with reversed-phase sorbents (100 mg C8, 100 mg C18, and 30 mg Oasis-HLB) were studied. The highest and most reproducible recoveries were obtained using a 30 mg Oasis-HLB sorbent and methanol containing 2% acetic acid as eluent. Enrichment by a factor of about four times was achieved by reconstituting the final SPE eluates to a small volume. For the CZE separation, good separations without interfering peaks due to the in vitro matrix were obtained with a simple running electrolyte using a fused-silica capillary. The best separation for all components originated by each tested drug after incubation with human liver microsomes (unmetabolized parent drug and its metabolites) was obtained using a 0.05 M phosphate running buffer (pH 2.2) without additives. The effect of the injection volume was also investigated in order to obtain the best sensitivity. Performance levels in terms of precision, linearity, limits of detection, and robustness were determined.

Acetic Acid↗
PubMed2001

[Infectious complications associated with liver transplantation: analysis of 104 patients].

OBJECTIVE: Infectious complications are the main cause of morbidity and mortality during the first year after liver transplantation. The aim of the present study was to determine the incidence, microorganisms and factors associated with the development of infectious complications. PATIENTS AND METHOD: Retrospective analysis of infectious episodes during the first year after transplantation in 104 patients undergoing transplantation between April 1995 and December 1996. The various clinical variables related to the pre-transplant disease, the surgical intervention and post-transplant evolution were evaluated with the aim of identifying predictive factors for the development of bacterial infectious complications. RESULTS: During the first year, 51 patients (49%) presented 111 infectious episodes. The most frequent infections were bacterial (66%); 21% were cytomegalovirus infections and 22% were fungal. The incidence of bacterial infections was highest during the first month (80% of all infectious episodes in this period). Two variables were independently associated with the development of bacterial infections in the first month following transplantation: prolonged ischemia of the graft (p = 0.002) and length of stay in the intensive care unit (p = 0.002). Infectious complications caused 8 of the 11 deaths that occurred during the 1-year follow-up. Mortality associated with invasive fungal infections was 100%. CONCLUSIONS: Although the overall incidence of infections and associated mortality has decreased, it remains the main cause of mortality and morbidity in the first year after transplantation.

Female↗
PubMed2001

[Shock secondary to extrinsic compression of the right atrium by postoperative mediastinal hematoma. Pseudotumor echocardiography image in right atrium].

We present the case of a 64 year-old patient in whom an aortic Saint Jude prosthesis, a Cosgrove's mitral annulus and triple coronary artery by-pass graft were implanted, and who presented with shock related to extrinsic compression of the right atrium by a mediastinal hematoma within the first postoperative month. Transthoracic echocardiogram showed a right atrial < >, hampering right atrium drainage. The extrapericardial location of the hematoma is of note and was diagnosed with the aid of thoracic computerized tomography. We present the case of a 64 year-old patient in whom an aortic Saint Jude prosthesis, a Cosgrove's mitral annulus and triple coronary artery by-pass graft were implanted, and who presented with shock related to extrinsic compression of the right atrium by a mediastinal hematoma within the first postoperative month. Transthoracic echocardiogram showed a right atrial < >, hampering right atrium drainage. The extrapericardial location of the hematoma is of note and was diagnosed with the aid of thoracic computerized tomography.

Heart Atria↗
PubMed2001

Nitrogen removal from wastewaters at low C/N ratios with ammonium and acetate as electron donors.

A denitrifying upflow anaerobic sludge blanket (UASB) reactor was operated at different nitrate loading rates at a C/N ratio of 1.2, with acetate as an electron donor. This resulted in an increase in the accumulation of nitrite. After this, the UASB reactor was supplemented with 100 mg NH4+-Nl(-1) d(-1), while acetate was gradually limited in the medium. This prevented nitrite accumulation at a C/N ratio of 0.6 due to an enhanced nitrite reduction rate achieved in the reactor. An increasing amount of ammonium was consumed when the C/N ratio was lowered in the medium. This suggested that ammonium was used as an alternative electron donor during denitrification, which is supported by nitrogen balances. Nitrite was shown to be toxic for the nitrogen removal process at 200-400 mg NO2--N(l(-1) when the C/N ratio was decreased to 0.4 leading to formation of ammonium. The present study showed that addition of ammonium as an alternative electron donor for denitrification achieved a nitrogen removal process with negligible accumulation of undesirable intermediates.

Acetates↗
PubMed2001

Angiotensin II AT(1) receptor antagonists and platelet activation.

Multiple factors are involved in thrombus formation and require complex and highly therapeutic strategies. Platelet activation plays a critical role in the genesis of acute coronary syndromes involving not only platelets but also endothelial cells, leucocytes and erythrocytes. Angiotensin II (Ang II) is a vasoconstrictor that could participate in the thrombotic process. Platelets also express Ang II AT1 type receptors on their surface. Losartan is a non-peptidic inhibitor of AT1 receptors. It has been demonstrated that losartan reduced platelet aggregation induced by the thromboxane A2 (TXA2) analogue U46619. This effect was not observed with the losartan metabolite EXP 3174. The effect of losartan was assessed in binding studies in which losartan competitively inhibited the binding of [3H]U46619 to platelets in a dose-dependent manner. Irbesartan also inhibits the TXA2 receptor in platelets, an effect that was not obtained with the active form of candesartan, CV11974, and with valsartan. These results suggest that the structural requirements necessary to antagonize the TXA2/PGH2 platelet receptor may be different from those involved in AT1 receptor antagonism. The in vivo relevance of the in vitro findings has been confirmed by the fact that in vivo administration of losartan decreases P-selectin expression in platelets obtained from stroke-prone spontaneously hypertensive rats.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed2001

Inhibition of platelet activation in stroke-prone spontaneously hypertensive rats: comparison of losartan, candesartan, and valsartan.

In vitro studies have suggested that losartan interacts with the thromboxane (TxA2)/ prostaglandin H2 (PGH2) receptor in human platelets, reducing TxA2-dependent platelet activation. The aim of this study was to evaluate the effect of different angiotensin II type 1 receptor antagonists in stroke-prone spontaneously hypertensive rats (SHRSP). The level of platelet activation was assessed by determining P-selectin expression in platelets by flow cytometry. The ex vivo adhesion of platelets was also analyzed. The number of platelets that expressed P-selectin in SPSHR was significantly increased (% P-selectin expression: WKY 4 +/- 0, 4%; SHRSP 15.5 +/- 0, 8% [n = 8], p < 0.05). In SHRSP receiving losartan (20 mg/kg body weight per day) the percentage of platelets expressing P-selectin fell to levels close to that observed in WKY. The number of platelets from SHRSP treated with valsartan and candesartan (20 mg/kg body weight per day for 14 days) that expressed P-selectin was not significantly different from those from untreated SPRHR. Only losartan treatment reduced ex vivo platelet adhesion to a synthetic surface. The antiplatelet effect of losartan does not appear to be related to the level of blood pressure reduction. In ex vivo experiments, losartan significantly reduced the binding of the radiolabeled TxA2 agonist U46619 to platelets obtained from SHRSP in a dose-dependent manner. Treatment with losartan reduced the number of activated platelets in SHRSP independently of its blood pressure effects. TxA2-receptor blockade is proposed as a mechanism by which losartan can prevent platelet activation.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed2001

Rotavirus-associated medical visits and hospitalizations in South America: a prospective study at three large sentinel hospitals.

BACKGROUND: Knowledge of the impact of rotavirus-associated disease on the health care systems of South America can aid in defining strategies for diagnosis, management and prevention. Up to date information on the impact of rotavirus disease in South America is scarce. AIM: To determine prospectively the impact of rotavirus disease as a cause of medical visits and hospitalizations at three large sentinel pediatric hospitals in Argentina, Chile and Venezuela. METHODS: A 2-year prospective surveillance for rotavirus-associated medical visits and hospitalizations was conducted during 1997 through 1998 at three large sentinel public hospitals, one each in Argentina, Chile and Venezuela. A common surveillance protocol was implemented at the three sites, and a representative number of nonbloody diarrhea stool samples from children <36 months of age were tested for rotavirus by enzyme-linked immunosorbent assay. RESULTS: For our target age group, acute diarrhea-associated medical visits/hospitalizations represented 41%/2%, 5%/6% and 9%/13% of all medical visits/all hospitalizations at the Argentinean, Chilean and Venezuelan sites, respectively (P < 0.001 for difference among the three sites). Rotavirus detection rates among a total of 5,801/1,256 medical visit/hospitalization diarrhea stool samples tested were 39%/71% in Argentina, 34%/47% in Chile and 29%/38% in Venezuela (P < 0.01 by chi square for difference among the three sites). Rotavirus was associated with a mean of 1.5, 1.8 and 3% of total medical visits and 1.6, 2.8 and 5% of hospitalizations among children <36 months of age at the Argentinean, Chilean and Venezuelan sites, respectively. Seasonality was evident for medical visits at all three sites (although less striking in Chile) with peak activity occurring between November and May. Rotavirus-associated hospitalizations had a marked peak in Venezuela, represented largely by short stays, but not in Argentina and Chile. CONCLUSIONS: Rotavirus was a significant cause of medical visits at all three sentinel sites. Rotavirus caused less hospitalizations than previously reported in Argentina and Chile. On the basis of our findings we estimate that approximately 106,000/ 21,000, 48,000/8,000 and 98,000/31,000 rotavirus-associated medical visits/hospitalizations occur yearly in Argentina, Chile and Venezuela, respectively.

Argentina↗