[Mediastinal choriocarcinoma. A case report].
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Antineoplastic Agents↗
Biomedical subjects
G Gómez
Publications and source records attributed to G Gómez.
Does angina the week before protect against first myocardial infarction in elderly patients?
Mortality rates for coronary artery disease are greater in elderly patients. Although prodromal angina occurring shortly before an acute myocardial infarction (MI) has protective effects against ischemia, this effect has not been well documented in older patients. This study investigated whether angina 1 week before a first MI provides protection in this group of patients. A total of 290 consecutive elderly (>64 years old, n = 143) and adult patients (<65 years old, n = 147) with a first MI were examined to assess the effect of preceding angina on the short- and long-term prognosis. Elderly patients with a history of prodromal angina were less likely than those without angina to experience in-hospital death, heart failure, or the combined end point of in-hospital death and heart failure (6% vs 20.4%, p = 0.02; 10% vs 23.7%, p = 0.07; 14% vs 32.3%, p = 0.01, respectively). Left ventricular function was more frequently depressed (ejection fraction <40%) in elderly patients without (44.8%) than with (26%, p = 0.04) preinfarction angina, and the incidence of arrhythmias (complete heart block and ventricular fibrillation) was greater in the former group (16.1% vs 4%, p = 0.03). Multivariate analysis confirmed that the presence of preinfarction angina was an independent predictor of in-hospital death and heart failure in older patients (odds ratio 0.28, p = 0.009). The occurrence of angina 1 week before a first MI may confer protection against in-hospital adverse outcomes, and may preserve left ventricular function in older patients.
Aged↗
[The influence of angina the week before a first myocardial infarction on short and medium-term prognosis].
INTRODUCTION AND OBJECTIVES: The implications of early angina on the prognosis of myocardial infarction are controversial. The aim of this study was to assess the effect of angina one week before the first myocardial infarction on short and medium-term prognosis. PATIENTS AND METHOD: A total of 290 consecutive patients (107 with previous angina and 183 without it) with the first myocardial infarction were studied to determine the effect of preceding angina on short and medium-term prognosis. Further criteria for inclusion were no previous history of angina > 1 week before the first myocardial infarction, and no evidence of prior structural cardiopathy. The end points studied were death and congestive heart failure in the acute phase of myocardial infarction and during the follow-up. RESULTS: Patients with a history of prodromal angina were less likely to experience in-hospital death, heart failure or combined end-point (3.7 vs 11.5%; 4.6 vs 15.8%; 7.5 vs 21.3%) (p = 0.002). There was also a difference between groups in the follow-up (4.1 vs 13.2%; p = 0.03). Multivariate analysis confirmed that the presence of preinfarction angina was an independent predictor of death and heart failure in the acute phase of myocardial infarction as well as in the follow-up. CONCLUSIONS: The occurrence of angina one week before the first myocardial infarction protects against death and heart failure in the acute phase of myocardial infarction as well as in the medium follow-up.
Analysis of Variance↗
Effect of initial buffer composition on pH changes during far-from-equilibrium freezing of sodium phosphate buffer solutions.
PURPOSE: This study aims to assess the pH changes induced by salt precipitation during far-from-equilibrium freezing of sodium phosphate buffers as a function of buffer composition, under experimental conditions relevant to pharmaceutical applications-sample volumes larger than a few microliters, experiencing large degrees of undercooling and supersaturation. METHODS: Buffer solutions were prepared by dissolving the monosodium and disodium phosphate salts in the appropriate ratios to obtain initial buffer concentrations in the range of 8-100 mM and pH values between 5.7 and 7.4 at 25 degrees C. Temperature and pH were monitored in situ during cooling to -10 degrees C (at a rate of 0.3 to 0.5 degrees C/min) and for 10-20 min after the sample reached the final temperature. Salt crystallization was confirmed by ion analysis and x-ray powder diffraction. RESULTS: Precipitation of Na2HPO4, 12H2O caused abrupt pH decreases after the onset of ice crystallization, at temperatures between -0.5 and -4.0 degrees C. Decreasing the initial buffer concentration and/or initial pH resulted in higher final pH values at -10 degrees C, farther removed from the equilibrium value of 3.6. At an initial pH of 7.4, the 50 and 100 mM buffer solutions reached a pH of 4.2 +/- 0.1 at -10 degrees C, whereas the 8 mM solutions reached a pH of 5.2 +/- 0.2. Solutions having an initial pH of 5.7 and initial buffer concentrations of 8 and 100 mM experienced less pH shifts upon freezing to -10 degrees C, with final pH values of 5.1 +/- 0.1 and 4.7 +/- 0.1, respectively. CONCLUSIONS: Precipitation-induced pH shifts are dependent on the concentrations (activities) of precipitating ions, and are determined by both initial pH and salt concentration. The ion activity product is a meaningful parameter when describing salt precipitation in solutions prepared by mixing salts containing precipitating and nonprecipitating ions.
Buffers↗
Identification of an in vitro ribonucleoprotein complex between a viroid RNA and a phloem protein from cucumber plants.
We used the interaction of Hop stunt viroid (HSVd) and cucumber plants to investigate the involvement of phloem proteins in the systemic transport of RNA molecules. A ribonucleoprotein complex, stable even at high salt and temperature conditions, was detected in vitro between HSVd-RNA and the phloem exudate obtained from sectioned internodes from cucumber plants. The phloem protein 2 was recovered from this ribonucleoprotein complex and its RNA-binding properties as demonstrated by gel retardation analysis. The involvement of this protein in the movement of RNAs in cucumber is discussed.
Cucumis sativus↗
Oat-cell carcinoma of the prostate. Diagnosis, prognosis and therapeutic implications.
BACKGROUND: Any carcinoma of prostatic origin which is not an acinary adenocarcinoma of the prostate is considered to be an atypical carcinoma. One member of this group of atypical prostatic tumors is the oat-cell carcinoma, or small cell carcinoma (SCC) of the prostate. This variety of carcinoma constitutes the histologic basis of <1% of all prostatic neoplasms. METHODS: Between 1992 and 1997, four patients were diagnosed with SCC of the prostate at our hospital. In 3 of the 4 cases, the histopathological diagnosis was pure SCC, and in the 4th case there was a component of prostatic adenocarcinoma associated with the SCC. At the time of diagnosis, extracapsular extension of the tumor was present in all 4 cases, with T3 or higher stages in all of them (T(3A)N(0)M(1), T(3A)N(0)M(0), T(3B)N(0)M(1), and T(4)N(0)M(0)). Because of the presence of extracapsular extension, radiotherapy and radical surgery were ruled out for all 4 patients. They were all offered systemic chemotherapy with cyclophosphamide (1 g/m(2)), doxorubicin (50 mg/m(2)) and vincristine (1.2 mg/m(2)). This therapeutic protocol was carried out in only 2 cases. RESULTS: Survival was <1 year in the 3 patients with pure SCC, and the patient with a mixed tumor is alive with detectable disease 9 months after diagnosis. CONCLUSIONS: This poor vital prognosis in SCC stresses the need for early diagnosis a timely and appropriate therapeutic intervention in this condition.
Adult↗
[Prevalence of sub-clinical vitamin A deficiency and malnutrition in slum children in Maraicabo - Venezuela].
The present cross sectional study was carried out to estimate the prevalence of vitamin A deficiency among children by means of clinics and conjunctival impression cytology (CIC), and nutritional status by anthropometric indicators H//A, W//A, W//H. The study population included 157 children 2-6 y old, from urban and rural slums of Maracaibo, Venezuela, Conjunctival impression cytology was performed by ICEPO standard procedure. Z-score was applied to anthropometric data with reference values of NCHS-WHO. No evidence of clinical or ophthalmologic signs of vitamin A deficiency were detected. The prevalence of subclinical vitamin A deficiency, as detected by abnormal CIC, was 35.4%, being higher in rural children (48.3%). These prevalence values are higher than the criteria laid down by WHO/UNICEF to indicate a public health problem (> 20%). Mild or moderate protein-energy global malnutrition and stunting were detected in 36.1% and 44.6% of children, respectively. Abnormal CIC was indistinctly observed (approximately equal to 35%) as much in children with adequate nutrition as in malnourished ones. There was no significant difference in the distribution of the CIC results in relation to nutritional status. The findings indicate that CIC and Z-score of nutritional anthropometric data are useful to characterize the risk of vitamin A deficiency and of malnutrition in communities. Beside the implementation of an integral nutritional program which includes supplementation, food fortification and dietary diversification, improvement of socio-economic and sanitation conditions and also the educational level, with emphasis on nutritional and health education, are highly recommended.
Anthropometry↗
Risk of HIV infection as a function of the duration of intravenous drug use: a non-parametric Bayesian approach.
We analyse the elapsed time between intravenous (IV) drug initiation and HIV infection in a cohort of 972 injecting drug users attending a hospital detoxification unit. We use the time of seroconversion instead of the time of HIV infection because the date of HIV infection is rarely known and the gap between these two times is negligible (around one to three months). Although seroconversion time cannot be determined exactly, it can be inferred at least to within an interval. This seroconversion interval is determined from the dates of HIV antibody tests, if available. The data is consequently interval-censored. We estimate the distribution function of the elapsed time from IV drug initiation to seroconversion as well as the risk of seroconversion by means of a non-parametric Bayesian approach. The analysis is conducted according to the following four calendar periods: before or at 1980; between 1981 and 1985; between 1986 and 1991; after or at 1992 where the IV drug use was initiated. The methodology used is based on an alternating conditional sampling algorithm. The Bayesian approach allows not only the incorporation of prior beliefs about the distribution function, but also the analysis of the risk of seroconversion without assuming restrictive parametric models. Furthermore, the estimator for the distribution function is smooth and thus differences between groups can be easily interpreted.
Adolescent↗
Systemic lupus erythematosus: mortality and survival in Argentina. A multicenter study.
OBJECTIVE: To analyze the factors associated with mortality, survival and causes of death in patients with systemic lupus erythematosus (SLE) in Argentina. PATIENTS AND METHOD: A series of 366 patients with SLE (45 men and 321 women), mean age 29 y (range 11-70 y) and mean disease duration 6 y, was evaluated from 1990 to 1998. A total of 57 clinical, serological and therapeutic variables were studied. RESULTS: Five- and 10-year survival was 91% and 85% respectively. Forty four patients died (12%): 54% due to sepsis and 32% due to active SLE. Mortality risk factors included heart involvement CRR 3.82), hyperlipidemia (RR 2.72), renal damage (RR 2. 62), infections (RR 2.44), lung disease (RR 2.20) and myositis (RR 2. 07). High-dose prednisone (RR 3.4) or cyclophosphamide (RR 9.19) treatments increased the risk of sepsis (P=0.003) as a cause of death. However, corticosteroids, antimalarial agents and accumulated cyclophosphamide doses proved to be protective factors in overall mortality figures (RR <1). CONCLUSIONS: The main risk factors of death in SLE were heart involvement, hyperlipidemia and renal damage. Treatment with steroids, antimalarial agents and cyclophosphamide improved survival. High-dose corticosteroids and cyclophosphamide were associated with sepsis as a cause of death.
Adolescent↗
Dynorphin A increases substance P release from trigeminal primary afferent C-fibers.
Dynorphin A-(1-17) has been found to produce spinal antianalgesia and allodynia. Thus, we studied whether dynorphin A-(1-17) modulates substance P release evoked by the C-fiber-selective stimulant capsaicin (1 microM) from trigeminal nucleus caudalis slices. Very low concentrations of dynorphin A-(1-17) (0.01-0.1 nM) strongly facilitated capsaicin-evoked substance P release. This dynorphin A-(1-17) effect was not blocked by the opioid receptor antagonists naloxone (100 nM), beta-funaltrexamine (20 nM), naloxonazine (1 nM), nor-binaltorphimine (3 nM) and ICI 174,864 (N,N-dialyl-Tyr-Aib-Phe-Leu; 0.3 microM). Yet, the effect of dynorphin A-(1-17) was blocked by the NMDA receptor antagonist MK-801 ((+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d] cyclohepten-5-10-imine maleate; 0.3 microM). Neonatal treatment with capsaicin (50 mg/kg s.c.), which destroys substance P-containing primary afferents, abolished the excitatory effect of dynorphin A-(1-17) on K+-evoked substance P release. In conclusion, dynorphin A-(1-17) increases substance P release from C-fibers by the activation of NMDA receptors which supports the involvement of presynaptic mechanisms in dynorphin-induced antianalgesia and allodynia.
Animals↗
Evolution of streptozotocin-pancreatic damage in the rat: modulatory effect of endothelins on the nitridergic and prostanoid pathway.
Many lines of evidence indicate that an increased pancreatic production of nitric oxide (NO) and prostaglandins (PGs) is found in the pancreas of streptozotocin-diabetic rats and that endothelins (ETs) are closely related to the nitridergic and prostanoid pathway in several tissues. In the present study the relationship between NO, ETs, and PGs has been explored in isolated pancreatic tissue from streptozotocin-diabetic rats. Pancreatic ET levels are higher in pancreatic tissues from diabetic (D) rats compared to control (C) animals. The addition of nitric oxide synthase (NOS) inhibitors (1 mM N(G)-nitro-l-arginine methyl ester, 600 microM N(G)-monomethyl-l-arginine) in the incubating medium reduces and NO donors (SIN-1, 300 microM spermine suppress, NONOate 100 microM) increases ET levels in pancreatic slices from C and D animals. PGE(2) (10(-7) M) increases and indomethacin (10(-6) M) decreases ET pancreatic production only in D but not in C tissues when added into the incubating bath. When tissues are incubated in the presence of endothelin 1 (ET-1) (10(-7) M), NOS activity is higher in C pancreas, while the ET-receptor antagonist bosentan (B) decreases NOS levels in D but not in C tissues. When pancreatic arachidonic acid (AA) conversion to prostaglandins was explored, ET-1 increased PGF(2alpha), PGE(2), and TXB(2) levels in C but not in D tissues. B abolishes TXB(2) increment due to the diabetic state, but failed in modulating AA conversion to 6-keto PGF(1alpha), PGF2(alpha) and PGE(2) in D pancreas. Our results show an alteration in AA metabolism, ET production, and NO increment associated with pancreatic damage due to streptozotocin.
Animals↗
Acute tacrolimus nephrotoxicity in renal transplant patients treated with clarithromycin.
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Adult↗
Fluvastatin in the treatment of hypercholesterolemia in renal transplantation.
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Anticholesteremic Agents↗
Effect of atorvastatin of the treatment of hypercholesterolemia after renal transplantation.
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Anticholesteremic Agents↗
Multiphasic morphine modulation of substance P release from capsaicin-sensitive primary afferent fibers.
Morphine produces a multiphasic modulation of K+-evoked substance P release from trigeminal slices and dorsal root ganglion neurons in culture. We now found that the C-fiber stimulant, capsaicin (1 microM), evoked release of substance P that was inhibited, enhanced and inhibited by 0.1 nM, 1 microM, and 10 microM morphine, respectively. This morphine's multiphasic effect was blocked by naloxone (100 nM). Neonatal treatment with capsaicin produced thermal hypoalgesia and abolished the multiphasic effect of morphine on substance P release evoked by 50 mM K+. These findings suggest that the multiphasic modulation of substance P release by morphine is dependent on C-type afferents and may be of relevance to nociception.
Animals↗
Arachidonic acid metabolites in CSF in hypoxic-ischaemic encephalopathy of newborn infants.
The aim of this study was to evaluate the cerebral synthesis of eicosanoids in the asphyctic newborn and to investigate the relation between the prostanoid profiles in cerebrospinal fluid (CSF) and the appearance and severity of hypoxic-ischaemic encephalopathy (HIE). Levels of 6-keto-PGF(1-alpha), TXB2, PGE2 and PGF(2-alpha), in CSF were measured in 40 full term newborns during the first day of life. Thirty of these newborns had birth asphyxia and were divided into three groups: 10 without HIE, 12 with mild HIE and 8 with moderate-severe HIE. They were compared to a control group of 10 non-hypoxic newborns. Determinations of the metabolites in CSF were performed by RIA and expressed as pg/ml (mean +/- SD). The CSF TXB2 (thromboxane A2 metabolite) in asphyxiated newborns was always higher than in the control group (28.12 +/- 10.6), and related to the severity of HIE (p = 0.005): without HIE (50.84 +/- 16.4; p = 0.02), mild HIE (80.65 +/- 12.64; p < 0.01) and moderate-severe HIE (178.14 +/- 20.5; p < 0.01). The CSF 6-keto-PGF(1-alpha) (prostacyclin metabolite) in asphyxiated newborns was always higher than in the control group (80.55 +/- 12.56), but indirectly related to the severity of HIE: without HIE (240.95 +/- 28.12; p < 0.01), mild HIE (183.65 +/- 30.1; p < 0.01) and moderate-severe HIE (140.55 +/- 25.12; p < 0.01). In the moderate-severe HIE group, the increase in TXB2 was higher than the rise in 6-keto-PGF(1-alpha).
Arachidonic Acids↗
Left-truncated data with age as time scale: an alternative for survival analysis in the elderly population.
BACKGROUND: The standard approach for survival analysis of the elderly population is to define the survival time as the elapsed time from entry into the study until death, and to adjust by age using stratification and regression procedures. However, the interest is in the study of the aging process and the risk factors related to it, not in the use of time-on-study as the time scale. Here, we present methods to use age as the time scale and compare inferences and interpretations with those obtained using the standard approach. METHODS: A total of 1,315 individuals aged 65 years or older from the city of Barcelona, Spain, were interviewed in 1986 (baseline). The vital status of the cohort was assessed in October 1994. To illustrate the usefulness of age as time scale (alternative approach) instead of time-on-study in the survival analysis of the elderly population, both methods were used to assess the relationship between baseline functional capacity and mortality. RESULTS: Using the alternative approach, we observed that 50% of the sample died at age 80.6 years; this information could not be estimated with the standard approach. Using age as a covariate in the standard analysis with time-on-study as the time scale and using age as the time scale in the alternative analysis, the association of functional capacity at baseline and mortality was of similar magnitude under both analyses. Nevertheless, using the alternative approach, relative risks were slightly lower, and the adjustment by age was tight and was not subject to the inherent assumptions in regression models of the functional relationship of independent variables with outcome. We illustrated the methods with fixed covariates (i.e., gender) and baseline values of time-dependent covariates (i.e., functional capacity), but we discussed the extension of our methods for the analysis of time-dependent covariates measured at several visits in a cohort study. Methods proposed here are easily implemented with widely available statistical software packages. CONCLUSIONS: Although the use of standard survival analysis generally produces correct estimates, the use of age as time scale is deemed more appropriate for survival analysis of the elderly: Inferences are easier to interpret and final models are simpler. We therefore recommend the use of age as time scale for survival analysis of the elderly population.
Aged↗
CD4+ lymphocytes and tuberculin skin test as survival predictors in pulmonary tuberculosis HIV-infected patients.
BACKGROUND: We analyse whether the tuberculin skin test is a good survival marker in a cohort of pulmonary tuberculosis patients with HIV infection (PTB/HIV). In all, 494 PTB/HIV patients were enrolled in Barcelona (Spain) between January 1992 and December 1994 in the Tuberculosis Program of Barcelona. The main data problem was the large proportion of missing values in the covariates percentage of T CD4+ lymphocytes and the tuberculin test results: only 157 patients (31.8%) had both covariates recorded. METHODS: Patients were dichotomized into two groups according to their level of immunosuppression (< or = 14 and >14% T CD4+ cells). First, we carried out the semiparametric and parametric complete case analysis. After this, we analysed the data assuming a missing at random non-response pattern. We developed a bootstrap approach where missing data in the markers are imputed via a two-way linear model. Using Weibull regression estimation, we used a multiple imputation scheme to estimate the parameters of interest. RESULTS: We found significative differences for the most immunosuppressed group when comparing positive tuberculin patients with those who were tuberculin negative. From a complete case approach and through a multivariate Cox analysis, we obtained a significant relative hazard of 0.3657 (95% CI: 0.13-1.02; P = 0.054). When a Weibull model was fitted, we estimated a constant relative percentile value of pR = 4.1329 (95% CI: 0.97-17.59). From a missing data approach, we obtain a higher constant relative percentile 5.48 (P = 0.079). CONCLUSIONS: The imputation method allows us to assess the protective character of positivity for the tuberculin test for the lowest CD4+ level. These findings strongly suggest the value of the tuberculin skin test as a qualitative measure of the immunological response and its interest for developing countries where specific laboratory tests are not affordable.
Adult↗