Hipertensión arterial de díficil control asociada a masa abdominal / Resistant hypertension associated to an abdominal mass

La palpación de una masa abdominal y la presencia de hipertensión de difícil control debe hacernos pensar en la posible existencia de un feocromocitoma. El feocromocitoma maligno representa entre el 2 y el 11% de los tumores neuroendocrinos, productor de catecolaminas, en el que la tríada clínica típica no siempre está presente, siendo la clínica bastante variable. El patrón nodipper en la monitorización ambulatoria de la presión arterial (MAPA), la determinación de metanefrinas plasmáticas y cromogranina A, junto a las pruebas de imagen realizadas, confirmaron el diagnóstico. Son de mal pronóstico, con una supervivencia menor del 50% a los 5 años. Su tratamiento se basa principalmente en la exéresis del tumor. Suelen ser radiorresistentes y la respuesta a la quimioterapia es mínima, por lo que el tratamiento suele tener un enfoque principalmente paliativo (AU)

Palpation of an abdominal mass and the presence of difficult-to-control hypertension should make us consider the possible existence of a pheochromocytoma. Malignant pheochromocytoma accounts for 2-11% of neuroendocrine tumors, catecholamine producing tumors, in which the typical clinical triad is not always present because of the variety of their clinical presentations. Diagnosis is confirmed through the nondipper pattern in the ambulatory blood pressure monitoring (ABPM) study, the measurement of plasma metanephrines and chromogranin A, as well as the imaging tests. Pheochromocytomas have a bad prognosis, survival being less than 50% at 5 years. The main treatment is tumor excision. They are usually resistant to radiotherapy, and response to chemotherapy is minimum. Thus, the treatment approach is often mainly palliative (AU)

Psychonephrology: psychological aspects in autosomal dominant polycystic kidney disease.

The biological, physical and psychological burden of a chronic disease has an impact on the quality of life of people who suffer from it. The perception of quality of life is affected by psychological disorders such as anxiety and depression that have a high prevalence in people with chronic kidney disease (CKD). These factors are also linked to lower life expectancy. It is therefore surprising that the psychological aspects of people with autosomal dominant polycystic kidney disease (ADPKD) have received so little attention in the medical literature, despite their importance for the overall health of these patients. The relatively new discipline called psychonephrology provides a broader view of the impact that these aspects have on individuals with chronic kidney disease, with a consequent practical application. In this article, we examine the consequences and prevalence of psychological problems that can be related to CKD and ADPKD. Firstly, we will focus on the field of CKD and ADPKD within the scope of psychonephrology. Secondly, the article introduces the concept of quality of life as a basic pillar of health that is affected when a person is diagnosed with CKD. Thirdly, we will present a summary of the main research related to anxiety and depression disorders in CKD and ADPKD. The article will conclude by synthesising findings from the different lines of research undertaken.

Aspectos vasculares y metabólicos de manidipino / Vascular and metabolic properties of manidipine

En el tratamiento de la hipertensión y la diabetes, la combinación de bloqueantes del sistema renina-angiotensina y de los canales de calcio se presenta como una de las opciones más eficaces. Sin embargo, no todos los bloqueantes de calcio se comportan del mismo modo. Manidipino, a diferencia de otros derivados dihidropiridínicos de tercera generación, bloquea los canales de calcio T presentes en las arteriolas glomerulares eferentes, disminuyendo la presión intraglomerular y la microalbuminuria. Además, los canales T están relacionados con proliferación, inflamación, fibrosis, vasoconstricción y activación del sistema renina-angiotensina. La inhibición de estos factores podría explicar la acción no hemodinámica del manidipino frente a otros bloqueantes (AU)

The combination of renin-angiotensin system blockers with calcium channel blockers appears to be one of the most effective options for treating hypertension and diabetes. Nevertheless, not all calcium blockers behave in the same manner. Manidipine, unlike other third-generation dihydropyridine derived drugs, blocks T-type calcium channels present in the efferent glomerular arterioles, reducing intraglomerular pressure and microalbuminuria. In addition, T-type channels are related to proliferation, inflammation, fibrosis, vasoconstriction and activation of the renin-angiotensin system. The inhibition of these factors could explain the non-haemodynamic effects of manidipine as compared to other blockers (AU)

C282Y hemochromatosis gene mutation and iron parameters in dialysis patients.

BACKGROUND: Hereditary hemochromatosis is an autosomal recessive condition causing excessive intestinal iron absorption related to C282Y hemochromatosis mutation gene. Dialysis patients receive intravenous iron supplements as treatment for anemia. The gene mutation frequency and its influence on iron deposits and intravenous iron response are unknown in these patients. STUDY DESIGN: Prospective observational. SETTING AND PARTICIPANTS: 290 dialysis patients in Gran Canaria, Spain. OUTCOMES AND MEASUREMENTS: The C282Y hemochromatosis mutation gene was studied. Other active players in iron metabolism have not been included in this study. Red cell parameters, serum iron, transferrin and ferritin concentrations were measured every 2 months for 2 years. RESULTS: No differences in allelic and genotypic frequencies between dialysis patients and the general population were detected. Baseline clinical or analytical parameters were similar in C282Y +/- and C282Y -/- patients. Among those who did not need intravenous iron treatment, C282Y+/- patients maintained constant serum ferritin (302.1 ± 216.7 vs. 319.5 ± 300.5 µg/l after 4 months), whereas C282Y-/- patients showed decreased levels during the same period (306.7 ± 212.2 vs. 221.6 ± 167.8 µg/l, p < 0.001). After 4 months of parenteral iron, serum ferritin increased more intensely in C282Y +/- patients than in C282Y -/- patients (934.2 ± 195.8 vs. 658.7 ± 259.9 µg/l, p < 0.001). A multivariance analysis identified the C282Y allele as the most important factor that explains this difference. CONCLUSIONS: Heterozygosity for the C282Y allele of the hemochromatosis mutation gene could be associated with differences in iron parameters in dialysis patients.

Vascular and metabolic properties of manidipine.

The combination of renin-angiotensin system blockers with calcium channel blockers appears to be one of the most effective options for treating hypertension and diabetes.Nevertheless, not all calcium blockers behave in the same manner. Manidipine, unlike other third-generation dihydropyridine derived drugs, blocks T-type calcium channels present in the efferent glomerular arterioles, reducing intraglomerular pressure and microalbuminuria. In addition,T-type channels are related to proliferation, inflammation,fibrosis, vasoconstriction and activation of the renin-angiotensin system. The inhibition of these factors could explain the non-haemodynamic effects of manidipine as compared to other blockers.

Guía práctica a los estudios de asociación genética. Consideraciones sobre su utilidad clínica / No disponible

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[Genetic diagnosis of autosomal dominant polycystic kidney disease using multiplex-PCR]. / Diagnóstico genético de poliquistosis renal autosómica dominante mediante PCR múltiple.

BACKGROUND: Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common life-threatening hereditary disease. Molecular analysis with highly polymorphic short tandem repeats, located in the vicinity of the two genes responsible for the disease (PKD1 and PKD2), is used to confirm diagnosis and give genetic counseling to members of affected families. METHODS: We have developed a new assay to genotype five PKD1 and four PKD2 markers, based on two multiplex PCR reactions, and capillary electrophoresis analysis. A total of 110 subjects, belonging to 14 affected families, were genotyped to confirm the concordance with the singleplex method used previously. RESULTS: The amplicons ranged from 95 to 154 bp in length, and complete STR profiles were obtained from 1-5 ng DNA. The specificity of the multiplex PCR system was 88,5% (95%CI= 75,9-95,2), and the sensitivity, 87,9 (95%CI= 76,1-94,6). CONCLUSIONS: This is a useful strategy that, together with automated computer-based allele detection, allows reliable, simple, faster, and cheaper genetic analysis than the previous singleplex method.

Propiedades cardiometabólicas del manidipino: ¿más allá de la reducción de la presión arterial? / No disponible

Desde su introducción en la década de los 70, la evolución de los calcioantagonistas ha permitido solventar la incertidumbre inicialmente generada por aquellos fármacos deprimera generación. Éstos se caracterizan por una menor disponibilidad oral, una acción vasodilatadora rápida y corta acción. El manidipino surge como un derivado dihidropiridínico de tercera generación con ventajas adicionales reales frente a las generaciones anteriores, como son su alta lipofilicidad, su acción más prolongada y una vida media prolongada a nivel del receptor y, además, algunas ventajas teóricas entre otras, mejoras sobre la función renal reduciendo la presión intraglomerular y la microalbuminuria. Sin embargo, la evaluación clínica de estas últimas propiedades depende aún de los resultados que se deriven de la experiencia clínica. Además de ahondar ensu papel en la reducción de la presión arterial, presentamos una breve revisión sobre nuevos aspectos cardiometabólicos de los calcioantagonistas dihidropiridínicos, centrándonos en el manidipino (AU)

From its introduction in the decade of the 70’s the evolution of the calcium channel blockers has allowed to resolve the uncertainty initially generated by those first-generation drugs. These, are characterized by a smaller oral availability, a fast vasodilator action and a short duration of action. Manidipine arises as a dihydropyridinecalcium antagonist of third generation with real additional advantages regarding to previous generations. They show high lipophilia, a more prolonged action and as well as a prolonged average life at the level of his receptor and, in addition, some theoretical advantages among others calcium antagonists, improvements on the renal function by reducing the intraglomerular pressure and microalbuminuria. Nevertheless, the clinical evaluation of these last properties still depends on the results derived from clinical trials. Besides to go deep in its role in their antihypertensive effect, we presented a brief review on new cardiometabolic aspects of these dihydropyridines calcium antagonists focusing in manidipine (AU)

Insight into the role of CYBA A640G and C242T gene variants and coronary heart disease risk. A case-control study.

The CYBA gene variants have been inconsistently associated with coronary heart disease (CHD) risk. A case-control study was conducted genotyping 619 subjects to explore the contribution of C242T and A640G to CHD risk in the population. A significant risk was found associated with GG homozygosity (odds ratio (OR) 2.132, 95% confidence interval, 1.113-4.085). The C242T variant was associated with CHD risk in women. Bias due to population stratification was analysed. Phenotype changes linked to these polymorphisms were evaluated. Superoxide measurements revealed higher production as indicated by the presence of the G and T alleles. Differences in mRNA concentration in heterozygous A640G samples were analysed. Higher levels of G allele mRNA compared with A allele mRNA were found. NAD(P)H oxidase p22phox sub-unit expression was evaluated with Western blot. Experiments revealed a gradual relationship in p22phox protein expression according to genotypes of the analysed variants. Those GG TT double homozygous showed increased p22phox protein expressions regarding AA CC double homozygous. This study has demonstrated increased expression and activity of the NAD(P)H system components during atherogenesis and the results could help explain the relevance of the A640G variant as a CHD marker.

[Arterial blood pressure variations: homocysteine and nitric oxide synthase gene polymorphisms (NOS3)]. / Presión arterial, homocisteína y variantes polimórficas del gen de la óxido nítrico sintasa (NOS3).

BACKGROUND: The nitric oxide synthase (NOS3) G894T gene polymorphism seems as a genetic determinant of total homocysteine (tHcy) concentrations through an effect on folate catabolism. We tested for a significant contribution to blood pressure values for the NOS3 G894T and 4a/b gene polymorphisms and whether those changes could explain the modulating effect on tHcy concentrations. PATIENTS AND METHODS: We analyzed 158 healthy men. The NOS3 gene polymorphisms were determined by polymerase chain reaction (PCR) and restriction fragment analysis (G894T) and by PCR (4a/b). Total homocysteine concentrations were evaluated by the fluorescence polarization immunoassay method. RESULTS: In our population we did not obtain a significant contribution of the G894T to blood pressure variations. However, tHcy mean concentration values differed according G894T genotypes (P = 0.01). Interestingly, we did not obtain a significant modulating effect on tHcy concentrations according to 4a/b genotypes although the 4a/b genotype distribution was statistically associated with blood pressure variations. CONCLUSION: Our results showed a modulating effect of the NOS3 4a/b gene variant on tHcy concentrations that is at least partially provoked by discrete blood pressure increments. Nevertheless, our multivariate analysis did not show a statistical significant role for the NOS3 G894T gene polymorphism on tHcy concentrations.

¿Qué son los genes Hox? Su importancia en la enfermedad vascular y renal / What are the hox genes? Its importance in vascular and renal diseases

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[Molecular diagnosis of adult dominant polycystic kidney disease in the Canary Islands]. / Diagnóstico molecular de la Poliquistosis Renal Autosómica Dominante en la Comunidad Autónoma de Canarias.

Adult dominant polycystic kidney disease is an hereditary condition responsible for 6% of end-stage renal failure in Spain. Two genes were located in chromosomes 16 and 4 as related to this age-dependent disease in the 90s (PKD1 and PKD2). The diagnosis can be easily achieved by sonographic study, but molecular analysis by means of linkage analysis has the advantage of an early diagnosis in asymptomatic genetic carriers, with a view to the preventive follow-up of these subjects and genetic counselling. In this paper we present the results of molecular analysis of 30 families with Adult Dominant Polycystic Kidney Disease (from the province of Las Palmas Spain), carried out linkage analysis with two series of microsatellite markers located within or in the vicinity ofPKD1 (D16S521, KG8, AC2.5, CW2, SM7) and PKD2 (D4S1538, D4S1534, D4S423,D4S414) genes. The objectives of the study were: first, to verify the informativeness, and therefore, the usefulness of these markers for family studies in our population; and second,to assess the sensitivity and specificity of the genetic analysis in our population. Most of the markers showed a high heterozygosity, comparable to data in other studies. Considering the alleles of the different markers together in a chromosome as an haplotype increased the informativeness of the markers, and allowed the unequivocal identification of genetic data in 97.7% of patients and 88.7% of healthy subjects. The sensitivity and specificity of the genetic analysis were 90.7% (CI 95%: 85.7-95.7) and 86.8% (CI 95%: 80.6-93.0), respectively.

Nefrología basada en investigación clínica: bases conceptuales para la constitución de un grupo de trabajo en Nefrología Basada en la Evidencia de la Sociedad Española de Nefrología / No disponible

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