Percepción del fraude científico en las revistas biomédicas españolas / Perception of scientific fraud in the Spanish biomedical journals

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Función renal relativa normalizada por volumen en la gamagrafía con 99mTc-DMSA: estudio basado en una población pediátrica / Volume normalized relative renal function in 99mTc-DMSA scintigraphy: study in a paediatric population

Objetivo Evaluar las diferentes características diagnósticas de la función renal relativa (FRR) y de la función renal relativa normalizada por volumen renal relativo (FRRN), con el fin de analizar la posible mejora diagnóstica que implicaría su uso conjunto. Métodos Hemos estudiado con 99mTc-DMSA 952 unidades renales (riñones individuales), que pertenecían a 476 pacientes pediátricos (269 niñas) de edades comprendidas entre 0 y 11 años. De ellas, 355 unidades renales se consideraron patológicas a partir del análisis visual gammagráfico. Se determinaron los puntos de corte más apropiados para establecer los valores normales de las funciones FRR y FRRN, considerando como patrón de referencia al análisis visual gammagráfico. Se realizaron curvas ROC y se calculó el índice “J de Youden” y la exactitud para diferentes puntos de corte desde 42 por ciento hasta 50 por ciento, tanto para la FRR como para la FRRN. Se realizó también un análisis bayesiano (global y parcial clasificando las unidades renales por indicaciones clínicas) de la FRR y la FRRN. Resultados Para la FRR el mejor punto de corte fue 45 por ciento y para la FRRN fue 47 por ciento. El análisis bayesiano global mostró mejores resultados de los diferentes parámetros estadísticos para la FRRN. El análisis bayesiano parcial indicaba un importante incremento de la sensibilidad en pacientes con patología de dilatación de vía: de 10 por ciento (FRR) a 74.6 por ciento (FRRN); y con pielonefritis aguda: de 29.2 por ciento (FRR) a 66.2 por ciento (FRRN) mientras que en pacientes con nefropatías crónicas la sensibilidad fue similar (70.1 por ciento). Conclusión El cálculo de la FRRN (punto de corte 47 por ciento) proporciona información útil y complementaria a la FRR, ya que cuantifica la calidad relativa del riñón independientemente del volumen renal y refleja mejor los hallazgos gammagráficos.

Purpose To assess the different diagnostic features of relative renal function (RRF) and volume normalized relative renal function (NRRF) with the aim of analysing the possible diagnostic improvement that would imply their joint use. Methods We studied 952 kidneys with 99mTc-DMSA, belonging to 476 paediatric patients (269 girls) aged 0-11 years. 355 out of total were considered pathologic (visual analysis). The most appropriate cut-off points for establishing normality of RRF and NRRF were determined, considering as gold standard the visual scintigraphic analysis. R.O.C. curves were performed, J Youden index and accuracy were calculated for the different cut-off points from 42 percent to 50 percent for RRF and NRRF. A bayesian analysis (global and partial according to clinical indications) of RRF and NRRF was also performed. Results For RRF the better cut-off point was 45 percent and for NRRF 47 percent. The global bayesian analysis showed better values of the different statistical parameters for NRRF. Partial bayesian analysis indicated an important increment of sensitivity in patients with dilated pyelocalicial system: from 10 percent (RRF) to 74.6 percent (NRRF); and acute pyelonephritis: from 29.2 percent (RRF) to 66.2 percent (NRRF) while the sensitivity in patients with chronic nephropathy remained stable (70.1 percent). Conclusion NRRF calculation (cut-off 47 percent) provides useful and additional information to RRF, as it quantifies the relative quality of kidney tissue regardless of renal volume and better reflects better the scintigraphic findings.

Prognostic relationship between two serial determinations of B-type natriuretic peptide and medium-long-term events in heart transplantation.

BACKGROUND: Persistent elevation of B-type natriuretic peptide (BNP) levels in the first year after transplant appears to be associated with an adverse prognosis. However, there are no data on the prognostic value of two serial determinations of BNP at the end of the first year after transplant in clinically stable patients. OBJECTIVES: The purpose of this study was to analyze the association between the increase in two serial determinations of BNP at the end of the first year and the subsequent development of events in medium-long-term follow-up. METHODS: An observational study was conducted in a consecutive series of 71 patients transplanted between January 1999 and January 2001. Patients who were "unstable" or had other conditions that could elevate BNP levels (rejection, elevated pulmonary pressures, renal dysfunction, depressed ventricular function or severe graft vascular disease) were also excluded. The final number of patients included was 51. BNP determinations were performed at 9 and 12 months post-transplant at the same time as biopsies. Three groups were formed depending on the relationship between the two determinations: Group 1 (20 patients), decrease >20%; Group 2 (16 patients), change <20%; and Group 3 (15 patients), increase >20%. The following were considered events: death; late rejection; and ventricular dysfunction associated or not with graft vascular disease. RESULTS: The baseline clinical profile was similar in the three groups. There was a significant difference in the rate of events (Group 1, 10%; Group 2, 32%; Group 3, 53%; p < 0.017). Event-free survival was statistically different between the groups (p = 0.017), mainly because of the large difference between Groups 1 and 3 (p = 0.003). Thus, cumulative event-free survival at 3,000 days was 89.4% for Group 1, 68.3% for Group 2 and 48.2% for Group 3. CONCLUSIONS: The increase between two serial determinations of BNP levels at the end of the first year post-transplant could identify a subgroup of patients with poor outcome.

Predictive value of brain natriuretic peptide in the diagnosis of heart transplant rejection.

AIM: To evaluate the pattern of brain natriuretic peptide (BNP) concentration in heart transplant (HT) recipients and its relation to the degree of graft rejection determined by endomyocardial biopsy specimen. METHODS: We studied 71 consecutive HT recipients (62 men, 53 +/- 11 years). The patients underwent 383 biopsies. Creatinine and BNP concentrations and hemodynamic parameters were determined along with the degree of graft rejection using endomyocardial biopsy specimens. We considered treatable rejection as International Society for Heart and Lung Transplantation Grade >or=2 in the first 90 days and >or=3A thereafter. We included a control group of 36 healthy individuals. RESULTS: Brain natriuretic peptide concentration was significantly greater among HT recipients (264 +/- 318 pg/ml) than in controls (17 +/- 16 pg/ml). In the first 90 days, BNP concentration was significantly greater among the patients with graft rejection (510 +/- 470, n = 84, vs 278 +/- 255, n = 87; p < 0.0001), although the corresponding discriminatory capacity was small. After the first 90 days, BNP values were similar in patients with and without graft rejection (170 +/- 297, n = 17, vs 142 +/- 203, n = 195; p = not significant). Creatinine concentration increased with time after transplantation and did not correlate with BNP concentration. We observed significant positive correlation between BNP concentration and hemodynamic parameters. CONCLUSIONS: Brain natriuretic peptide concentration remains increased after HT, with stabilization after the 4th month. Brain natriuretic peptide concentrations are slightly greater among patients with treatable rejection, particularly in the first 90 days, although BNP concentration lacks discriminatory capacity to serve as a guide to performing biopsy.

Ventricular natriuretic peptide (BNP) in heart transplantation: BNP correlation with endomyocardial biopsy, laboratory and hemodynamic measures.

A prospective study of 81 heart transplant (HT) patients was carried out in order to evaluate the evolution of brain natriuretic peptide (BNP) levels in HT patients and compare them with the degree of rejection as determined by endomyocardial biopsy. All patients were subjected to endomyocardial biopsy (532), and determination of BNP and creatinine levels as well as hemodynamic parameters. A control group of 36 volunteers was included. BNP values were significantly greater in HT patients than in healthy volunteers. In the first 3 months, BNP levels in patients with treatable rejection were significantly greater than in patients without graft rejection, although evident overlapping was observed in both distributions and discriminatory potential was low. After the third month, BNP values were similar in patients with and without rejection. Creatinine levels were observed to increase over time after transplantation, but no correlation was observed between the creatinine and BNP levels. A significant positive correlation was observed between BNP and right ventricle and pulmonary arterial pressures.

Superscan pattern in a case of gastric adenocarcinoma

Previous reviews have include prostate, breast, bladder and colon cancer and lymphoma among the causes of a super bone scan but have not included stomach cancer. We report a 58 year-old female with an infiltrative gastric adenocarcinoma extended to the minor curvature and posterior side of fundus. Bone scintigraphy showed diffuse increased uptake typical of a "superscan" indicating bone metastases diffusely invading the bone marrow. Gastric carcinoma should be considered in the differential diagnosis of a "superscan" pattern

[Brain natriuretic peptide. Diagnostic value in heart failure]. / Péptido cerebral natriurético. Valor diagnóstico en la insuficiencia cardíaca.

BACKGROUND: Nowadays a number of diverse biochemical markers have been identified in patients with heart failure (HF) that could indicate the severity of the patients' illness. Among them, probably the most useful is brain natriuretic peptide (BNP) because it is easily obtained and because of its diagnostic and prognostic information. Our objective was to assess the association between BNP and other different associated variables previously known to be related to the evolution of HF, as well as its utility to distinguish systolic from diastolic HF. PATIENTS AND METHOD: We studied 114 patients admitted consecutively for symptomatic HF for all causes (age: 66 years, male: 60%). In all patients plasma BNP was measured, from the third day of admission, with a specific radioinmunoassay. Echocardiography was performed in 101 patients. RESULTS: BNP plasma levels increased in proportion to functional class (p = 0.01) and the degree of left ventricular dysfunction (p = 0.0001, r = 0.44). There was also an association between BNP and male sex (p = 0.008), higher plasmatic creatinine (p = 0.01, r = 0.25), Iarger ventricular diameters (p = 0.0001) and higher pulmonary systolic pressure (p = 0.001, r = 0.44). In the multivariate analysis, BNP was independently related to the rest of variables with left systolic ventricular function (p = 0.0001). Despite this association, we did not find a satisfactory cut-off value in BNP, with a good sensitivity and specificity value from the total number of patients, of which specifically systolic dysfunction as a cause of HF was detected. CONCLUSIONS: a) BNP increases proportionately to the left ventricular dysfunction and HF severity, and b) BNP is not a useful tool to distinguish systolic from diastolic HF.

Péptido cerebral natriurético. Valor diagnóstico en la insuficiencia cardíaca / Brain natriuretic peptide. Diagnostic value in heart failure

Introducción y objetivos. En la actualidad se han identificado diversos marcadores bioquímicos en la insuficiencia cardíaca (IC) que podrían indicarnos la gravedad del paciente. De entre ellos, el probablemente más útil por la facilidad de su obtención e información diagnóstica-pronóstica es el péptido cerebral natriurético (BNP). Nuestro objetivo fue analizar la asociación entre el BNP y diferentes variables asociadas a la IC, así como calcular su poder discriminante del tipo de IC (sistólica frente a diastólica).Pacientes y método. Estudiamos a 114 pacientes ingresados de forma consecutiva por IC descompensada, cualquiera que fuera su etiología (edad media: 66 años, varones: 60 por ciento). En todos ellos se determinó la concentración de BNP, en muestras sanguíneas obtenidas a partir del tercer día de ingreso hospitalario, mediante ensayo radioinmunométrico. En 101 pacientes se realizó estudio ecocardiográfico. Resultados. Las concentraciones plasmáticas de BNP fueron mayores en pacientes con grados avanzados de estadio funcional (p = 0,01), sexo masculino (p = 0,008), mayor creatinina plasmática (p = 0,01, r = 0,25), peor función sistólica del ventrículo izquierdo (p = 0,0001, r = 0,44), mayores diámetros ventriculares (p = 0,0001) y mayor presión sistólica de la arteria pulmonar (p = 0,001, r = 0,44). En el análisis multivariado, el BNP se asoció de forma independiente del resto de variables con la función sistólica del ventrículo izquierdo (p = 0,0001). A pesar de esta asociación, ningún valor de BNP fue capaz de discriminar con un adecuado valor de sensibilidad y especificidad, del total de pacientes con IC, cuáles presentaban disfunción sistólica. Conclusiones. a) El BNP aumenta de forma proporcional a la disfunción ventricular izquierda y la gravedad de la insuficiencia cardíaca, y b) el BNP no puede emplearse en el diagnóstico diferencial del tipo de IC (disfunción sistólica frente a diastólica (AU)