RESUMEN
Pheochromocytoma (PCC) and paraganglioma (PGL) are rare neuroendocrine tumors that are hereditary in up to 50% of patients. The gene encoding transmembrane-protein-127 (TMEM127) is one of the PCC/PGL-susceptibility genes with an autosomal dominant inheritance pattern. Here, we report 2 patients with bilateral PCC who both harbored a homozygous TMEM127-mutation. In a 31-year-old mentally retarded patient, the homozygous c.410-2A > G mutation was discovered during an update of DNA analysis. A 26-year-old mentally retarded patient was found to have a homozygous c.3G > A mutation. The parents of both patients were consanguineous. We reviewed previously reported clinical features of TMEM127 mutation carriers and compared our findings with case descriptions of homozygous mutations in other PGL/PCC-susceptibility genes. Homozygosity for an autosomal dominant inherited disorder is an extremely rare phenomenon and has, to our knowledge, not been reported before for the gene encoding TMEM127. In the present cases, the clinical picture does not seem to be very different from heterozygous TMEM127 mutation carriers, except for a relatively large tumor size and more pronounced plasma metanephrine concentration. It is unclear whether the mental retardation is causally related to homozygosity of the TMEM127 mutations. Updating genetic screening in patients in whom PCC/PGL has been diagnosed in the past should be considered as it might provide clinically relevant information.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/genética , Predisposición Genética a la Enfermedad , Proteínas de la Membrana/genética , Feocromocitoma/genética , Neoplasias de las Glándulas Suprarrenales/patología , Adulto , Femenino , Pruebas Genéticas , Mutación de Línea Germinal , Homocigoto , Humanos , Masculino , Persona de Mediana Edad , Feocromocitoma/patologíaRESUMEN
PURPOSE: Over the past several decades, many papers have been published about the usefulness of thyrotropin receptor antibodies (TRAbs) as biomarkers of Graves' ophthalmopathy (GO). However, results have been inconsistent. The purpose of this analysis is to determine a possible cause of these discrepancies and to examine the usefulness of TRAbs as biomarkers for GO, especially 'thyrotropin-binding inhibiting immunoglobulin (TBII)' and 'thyroid-stimulating antibody (TSAb)'. METHOD: 26 articles discussing the association between TRAbs and GO were selected which were then divided into three groups based on the study method and whether or not the patients had been treated for hyperthyroidism. From the results of the papers reviewed, a provisional conclusion was made and a theoretical model on the TBII-TSAb coordinate plane was developed to confirm that conclusion. RESULTS: TSAb is reported to be significantly or strongly associated with GO in the studies of pre- and post-treated patients for hyperthyroidism. TBII is positively correlated, negatively correlated or uncorrelated with GO in studies of pre-treated patients. However, it is generally agreed upon that TBII and GO are closely correlated in studies of post-treated patients. CONCLUSION: We conclude that the level of TBII may not be a reliable indicator of the current state of GO in pre-treated patients. Whereas, in post-treated patients, due to changes in the correlation between TBII and TSAb due to the effect of hyperthyroidism treatment, the level of TBII can be a more reliable indicator of GO. Furthermore, the current level of TBII is closely associated with the onset and severity of GO in the future and it can be a valid predictor of GO. However, the TSAb level appears to be more reliable.
Asunto(s)
Oftalmopatía de Graves/diagnóstico , Inmunoglobulinas Estimulantes de la Tiroides/sangre , Receptores de Tirotropina/inmunología , Biomarcadores/sangre , Oftalmopatía de Graves/sangre , Oftalmopatía de Graves/inmunología , HumanosRESUMEN
Cytochrome P450 3A4 (CYP3A4) is a key drug-metabolizing enzyme. Loss-of-function variants have been reported as rare events, and the first demonstration of a CYP3A4 protein lacking functional activity is caused by CYP3A4*20 allele. Here we characterized the world distribution and origin of CYP3A4*20 mutation. CYP3A4*20 was determined in more than 4000 individuals representing different populations, and haplotype analysis was performed using CYP3A polymorphisms and microsatellite markers. CYP3A4*20 allele was present in 1.2% of the Spanish population (up to 3.8% in specific regions), and all CYP3A4*20 carriers had a common haplotype. This is compatible with a Spanish founder effect and classifies CYP3A4 as a polymorphic enzyme. This constitutes the first description of a CYP3A4 loss-of-function variant with high frequency in a population. CYP3A4*20 results together with the key role of CYP3A4 in drug metabolism support screening for rare CYP3A4 functional alleles among subjects with adverse drug events in certain populations.
Asunto(s)
Citocromo P-450 CYP3A/genética , Etnicidad/genética , Frecuencia de los Genes/genética , Polimorfismo de Nucleótido Simple/genética , Alelos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/genética , Efecto Fundador , Haplotipos/genética , HumanosRESUMEN
BACKGROUND: Previous studies suggest that expression of hypoxia markers may be associated with response to antiangiogenic drugs. Thus, we aimed to identify predictors of sunitinib outcome in clear-cell renal cell carcinoma (ccRCC). PATIENTS AND METHODS: The expression of eight key proteins related to hypoxia (CAIX, HIF1A, HIF2A, VEGFA, VEGFR1, VEGFR2, VEGFR3 and PDGFRB) and P-glycoprotein were assessed by immunohistochemistry in 67 primary ccRCC samples from prospectively recruited patients treated with first-line sunitinib. The proteins expression, VHL inactivation and EGLN3 mRNA content were compared with the patients' response to sunitinib. RESULTS: High expression of HIF2A and PDGFRB was associated with better sunitinib RECIST objective response (P = 0.024 and P = 0.026; respectively) and increased VEGFR3 expression was associated with longer progression-free survival (P = 0.012). VEGFR3 overexpression showed a negative correlation with VEGFR3 polymorphism rs307826 (P = 0.002), a sunitinib resistance predictor. With respect to overall survival (OS), high VEGFA was associated with short (P = 0.009) and HIF2A with long (P = 0.048) survival times. High EGLN3 mRNA content was associated with shorter OS (P = 0.023). CONCLUSIONS: We found an association between several proteins involved in hypoxia and sunitinib efficacy. In addition, low VEGFR3 expression was associated with worse outcome and with VEGFR3 rs307826 variant allele, reinforcing VEGFR3 as a marker of sunitinib resistance.
Asunto(s)
Carcinoma de Células Renales/tratamiento farmacológico , Prolina Dioxigenasas del Factor Inducible por Hipoxia/genética , Indoles/uso terapéutico , Neoplasias Renales/tratamiento farmacológico , Pirroles/uso terapéutico , Receptor 3 de Factores de Crecimiento Endotelial Vascular/genética , Anciano , Anciano de 80 o más Años , Inhibidores de la Angiogénesis/efectos adversos , Inhibidores de la Angiogénesis/uso terapéutico , Antineoplásicos/efectos adversos , Antineoplásicos/uso terapéutico , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/biosíntesis , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Biomarcadores de Tumor/metabolismo , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/mortalidad , Hipoxia de la Célula/efectos de los fármacos , Supervivencia sin Enfermedad , Resistencia a Antineoplásicos , Femenino , Expresión Génica/efectos de los fármacos , Humanos , Inmunohistoquímica , Indoles/efectos adversos , Neoplasias Renales/genética , Neoplasias Renales/mortalidad , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Estudios Prospectivos , Pirroles/efectos adversos , ARN Mensajero/biosíntesis , Sunitinib , Sobrevida , Resultado del Tratamiento , Receptor 3 de Factores de Crecimiento Endotelial Vascular/biosíntesis , Receptor 3 de Factores de Crecimiento Endotelial Vascular/metabolismoRESUMEN
OBJECTIVE: To understand the public policy-making process as it relates to breast cancer care in five Latin American countries. METHODS: An exploratory-evaluative study was conducted in Argentina, Brazil, Colombia, Mexico, and Venezuela in 2010, with the selection of countries based on convenience sampling. Sixty-five semi-structured interviews were conducted with government officials, academics, and representatives of trade associations and civil society organizations. A content analysis of secondary sources was performed. Information sources, data, and informants were mixed using the triangulation method for purposes of analysis. RESULTS: The countries that have made the most progress in public policy-making related to breast cancer are Brazil and Mexico. Although Argentina, Colombia, and Venezuela do not have policies, they do have breast cancer care programs and activities. Two perspectives on the development of public policies became evident: the first includes the broad participation of both governmental and nongovernmental sectors, whereas the second, more narrow approach involves government authorities alone. CONCLUSIONS: The results point to significant differences in public policy-making related to breast cancer in the Region. They also show that greater progress has been made in countries where policies have been developed through inclusive participation processes.
Asunto(s)
Neoplasias de la Mama/terapia , Política de Salud , Femenino , Humanos , América LatinaRESUMEN
Pheochromocytomas (PCCs) and paragangliomas (PGLs) are catecholamine-secreting tumors of neural crest origin. Once collectively known as the '10% tumor', based on the frequency of inherited forms of the disease, they are now referred to as the '10-gene tumor', based on the number of susceptibility genes identified to date. Most familial cases of pheochromocytoma and/or paraganglioma and 10-20% sporadic cases carry germline mutations in VHL, RET, NF1, SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, or MAX. The finding of somatic mutations in VHL and RET in an additional 10-15% of tumors has brought the proportion of all patients with PCC and/or PGL due to a genetic disruption in these genes to approximately one half. These findings impact on the clinical management of patients. The diversity in the genetic etiology has transcription correlates, which are reflected in the 2 main transcription signatures underlying these mutations: a pseudohypoxic cluster (VHL and SDH gene mutation carriers) and a cluster rich in kinase receptor signaling and protein translation pathways (RET, NF1, TMEM127 and MAX mutation carriers). Recognition of these clusters offers clues to better understand tumor pathogenesis as well as a rationale for the development of targeted therapies. In this report we provide an overview of the transcription-based classification of PCCs and PGLs, an update on the more recently identified susceptibility genes and an outline of current gaps in this research field as well as challenges for the coming years.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/genética , Paraganglioma/genética , Feocromocitoma/genética , Neoplasias de las Glándulas Suprarrenales/congénito , Animales , Predisposición Genética a la Enfermedad , Humanos , Mutación , Paraganglioma/congénito , Feocromocitoma/congénitoRESUMEN
BACKGROUND: The synthesis of cellulose is among the most important but poorly understood biochemical processes, especially in bacteria, due to its complexity and high degree of regulation. In this study, we analyzed both the production of cellulose by all known members of the Rhizobiaceae and the diversity of Rhizobium celABC operon predicted to be involved in cellulose biosynthesis. We also investigated the involvement in cellulose production and biofilm formation of celC gene encoding an endoglucanase (CelC2) that is required for canonical symbiotic root hair infection by Rhizobium leguminosarum bv. trifolii. RESULTS: ANU843 celC mutants lacking (ANU843ΔC2) or overproducing cellulase (ANU843C2+) produced greatly increased or reduced amounts of external cellulose micro fibrils, respectively. Calcofluor-stained cellulose micro fibrils were considerably longer when formed by ANU843ΔC2 bacteria rather than by the wild-type strain, in correlation with a significant increase in their flocculation in batch culture. In contrast, neither calcofluor-stained extracellular micro fibrils nor flocculation was detectable in ANU843C2+ cells. To clarify the role of cellulose synthesis in Rhizobium cell aggregation and attachment, we analyzed the ability of these mutants to produce biofilms on different surfaces. Alteration of wild-type CelC2 levels resulted in a reduced ability of bacteria to form biofilms both in abiotic surfaces and in planta. CONCLUSIONS: Our results support a key role of the CelC2 cellulase in cellulose biosynthesis by modulating the length of the cellulose fibrils that mediate firm adhesion among Rhizobium bacteria leading to biofilm formation. Rhizobium cellulose is an essential component of the biofilm polysaccharidic matrix architecture and either an excess or a defect of this "building material" seem to collapse the biofilm structure. These results position cellulose hydrolytic enzymes as excellent anti-biofilm candidates.
Asunto(s)
Proteínas Bacterianas/metabolismo , Biopelículas/crecimiento & desarrollo , Celulasa/metabolismo , Celulosa/biosíntesis , Raíces de Plantas/microbiología , Rhizobium leguminosarum/enzimología , Proteínas Bacterianas/genética , Celulasa/genética , Mutación , Rhizobium leguminosarum/genética , Rhizobium leguminosarum/fisiología , Simbiosis , Trifolium/microbiologíaRESUMEN
BACKGROUND: Classical familial adenomatous polyposis (FAP) is characterized by the appearance of >100 colorectal adenomas. PATIENTS AND METHODS: We screened the APC and MUTYH genes for mutations and evaluated the genotype-phenotype correlation in 136 Spanish classical FAP families. RESULTS: APC/MUTYH mutations were detected in 107 families. Sixty-four distinct APC point mutations were detected in 95 families of which all were truncating mutations. A significant proportion (39.6%) had not been previously reported. Mutations were spread over the entire coding region and great rearrangements were identified in six families. Another six families exhibited biallelic MUTYH mutations. No APC or MUTYH mutations were detected in 29 families. These APC/MUTYH-negative families showed clinical differences with the APC-positive families. A poor correlation between phenotype and mutation site was observed. CONCLUSIONS: Our results highlight that a broad approach in the genetic study must be considered for classical FAP due to involvement of both APC and MUTYH and the heterogeneous spectrum of APC mutations observed in this Spanish population. The scarcely consistent genotype-phenotype correlation does not allow making specific recommendations regarding screening and management. Differences observed in APC/MUTYH-negative families may reflect a genetic basis other than mutations in APC and MUTYH genes for FAP predisposition.
Asunto(s)
Poliposis Adenomatosa del Colon/epidemiología , Poliposis Adenomatosa del Colon/genética , ADN Glicosilasas/genética , Genes APC , Poliposis Adenomatosa del Colon/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Lactante , Persona de Mediana Edad , Mutación Puntual , Pólipos/patología , EspañaRESUMEN
Neurotoxicity is one of the most relevant dose-limiting toxicities of the anticancer drug paclitaxel. It exhibits substantial interindividual variability of unknown molecular basis, and represents one of the major challenges for the improvement of paclitaxel therapy. The extensive variability in paclitaxel clearance and metabolism lead us to investigate the association between polymorphisms in paclitaxel elimination pathway and neurotoxicity. We selected 13 relevant polymorphisms in genes encoding paclitaxel metabolizing enzymes (CYP2C8, CYP3A4 and CYP3A5) and transporters (organic anion transporting polypeptide (OATP) 1B1, OATP1B3 and P-glycoprotein) and genotyped them in 118 Spanish cancer patients treated with paclitaxel. After adjusting for age and treatment schedule, CYP2C8 Haplotype C and CYP3A5*3 were associated with protection (hazard ratio (HR) (per allele)=0.55; 95% confidence interval (CI)=0.34-0.89; P=0.014 and HR (per allele)=0.51; 95%CI=0.30-0.86; and P=0.012, respectively) and CYP2C8*3 with increased risk (HR (per allele)=1.72; 95%CI=1.05-2.82; and P=0.032). In each case, the allele causing increased paclitaxel metabolism was associated with increased neurotoxicity, suggesting an important role for metabolism and hydroxylated paclitaxel metabolites. We estimated the HR per paclitaxel-metabolism increasing allele carried across the three polymorphisms to be HR=1.64 (95% CI=1.26-2.14; P=0.0003). The results for P-glycoprotein were inconclusive, and no associations were observed for the other genes studied. The incorporation of this genetic data in treatment selection could help to reduce neurotoxicity events, thereby individualizing paclitaxel pharmacotherapy. These results warrant validation in independent series.
Asunto(s)
Antineoplásicos Fitogénicos/efectos adversos , Hidrocarburo de Aril Hidroxilasas/genética , Citocromo P-450 CYP3A/genética , Neoplasias/tratamiento farmacológico , Síndromes de Neurotoxicidad/etiología , Paclitaxel/efectos adversos , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Anciano , Alelos , Antineoplásicos Fitogénicos/uso terapéutico , Citocromo P-450 CYP2C8 , Femenino , Estudios de Asociación Genética , Haplotipos , Humanos , Masculino , Persona de Mediana Edad , Síndromes de Neurotoxicidad/diagnóstico , Paclitaxel/uso terapéutico , Polimorfismo Genético , Polimorfismo de Nucleótido Simple/genética , EspañaRESUMEN
The rhizobia-legume, root-nodule symbiosis provides the most efficient source of biologically fixed ammonia fertilizer for agricultural crops. Its development involves pathways of specificity, infectivity, and effectivity resulting from expressed traits of the bacterium and host plant. A key event of the infection process required for development of this root-nodule symbiosis is a highly localized, complete erosion of the plant cell wall through which the bacterial symbiont penetrates to establish a nitrogen-fixing, intracellular endosymbiotic state within the host. This process of wall degradation must be delicately balanced to avoid lysis and destruction of the host cell. Here, we describe the purification, biochemical characterization, molecular genetic analysis, biological activity, and symbiotic function of a cell-bound bacterial cellulase (CelC2) enzyme from Rhizobium leguminosarum bv. trifolii, the clover-nodulating endosymbiont. The purified enzyme can erode the noncrystalline tip of the white clover host root hair wall, making a localized hole of sufficient size to allow wild-type microsymbiont penetration. This CelC2 enzyme is not active on root hairs of the nonhost legume alfalfa. Microscopy analysis of the symbiotic phenotypes of the ANU843 wild type and CelC2 knockout mutant derivative revealed that this enzyme fulfils an essential role in the primary infection process required for development of the canonical nitrogen-fixing R. leguminosarum bv. trifolii-white clover symbiosis.
Asunto(s)
Celulasa/metabolismo , Fabaceae/microbiología , Raíces de Plantas/microbiología , Rhizobium leguminosarum/enzimología , Simbiosis , Celulasa/genética , Celulasa/aislamiento & purificación , Celulosa/biosíntesis , Clonación Molecular , Fabaceae/citología , Genes Bacterianos , Ligamiento Genético , Medicago/citología , Medicago/microbiología , Datos de Secuencia Molecular , Mutación/genética , Fenotipo , Raíces de Plantas/citología , Rhizobium leguminosarum/citología , Rhizobium leguminosarum/genética , Nódulos de las Raíces de las Plantas/citología , Nódulos de las Raíces de las Plantas/microbiología , Plantones/microbiologíaRESUMEN
BACKGROUND: High glycemic Variability (HGV) has become a stronger predictor of hypoglycemia. However, clinical factors associate with HGV still are unknown. OBJECTIVE: To determine clinical variables that were associated with a coefficient of variation (CV) above 36% evaluated by continuous glucose monitoring (CGM) in a group of patients with diabetes mellitus. METHODS: A cohort of patients with type 2 diabetes (T2D) was evaluated. Demographic variables, HbA1c, glomerular filtration rate (GFR) and treatment regimen were assessed. A bivariate analysis was performed, to evaluate the association between the outcome variable (CV> 36%) and each of the independent variables. A multivariate model was constructed to evaluate associations after controlling for confounding variables. RESULTS: CGM data from 274 patients were analyzed. CV> 36% was present in 56 patients (20.4%). In the bivariate analysis, demographic and clinical variables were included, such as time since diagnosis, hypoglycemia history, A1c, GFR and treatment established. In the multivariate analysis, GFR <45 mL/min (OR 2.81; CI 1.27,6.23; p:0.01), A1c > 9% (OR 2.81; CI 1.05,7.51; p:0.04) and hypoglycemia history (OR 2.09; CI 1.02,4.32; p:0.04) were associated with HGV. Treatment with iDPP4 (OR 0.39; CI 0.19,0.82; p:0.01) and AGLP1 (OR 0.08; CI 0.01,0.68; p:0.02) was inversely associated with GV. CONCLUSION: Clinical variables such as GFR <45 mL/min, HbA1C>9% and a history of hypoglycemia are associated with a high GV. Our data suggest that the use of technology and treatments able to reduce glycemic variability could be useful in this population to reduce the risk of hypoglycemia and to improve glycemic control.
RESUMEN
Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors that arise from chromaffin cells of the adrenal medulla and the sympathetic/parasympathetic neural ganglia, respectively. The heterogeneity in its etiology makes PPGL diagnosis and treatment very complex. The aim of this article was to provide practical clinical guidelines for the diagnosis and treatment of PPGLs from a multidisciplinary perspective, with the involvement of the Spanish Societies of Endocrinology and Nutrition (SEEN), Medical Oncology (SEOM), Medical Radiology (SERAM), Nuclear Medicine and Molecular Imaging (SEMNIM), Otorhinolaryngology (SEORL), Pathology (SEAP), Radiation Oncology (SEOR), Surgery (AEC) and the Spanish National Cancer Research Center (CNIO). We will review the following topics: epidemiology; anatomy, pathology and molecular pathways; clinical presentation; hereditary predisposition syndromes and genetic counseling and testing; diagnostic procedures, including biochemical testing and imaging studies; treatment including catecholamine blockade, surgery, radiotherapy and radiometabolic therapy, systemic therapy, local ablative therapy and supportive care. Finally, we will provide follow-up recommendations.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/diagnóstico , Neoplasias de las Glándulas Suprarrenales/terapia , Paraganglioma/diagnóstico , Paraganglioma/terapia , Feocromocitoma/diagnóstico , Feocromocitoma/terapia , Neoplasias de las Glándulas Suprarrenales/genética , Neoplasias de las Glándulas Suprarrenales/patología , Cuidados Posteriores , Algoritmos , Biomarcadores de Tumor/sangre , Biomarcadores de Tumor/orina , Catecolaminas/antagonistas & inhibidores , Diagnóstico por Imagen/métodos , Asesoramiento Genético , Predisposición Genética a la Enfermedad , Pruebas Genéticas , Humanos , Estadificación de Neoplasias , Paraganglioma/genética , Paraganglioma/patología , Feocromocitoma/genética , Feocromocitoma/patología , Sociedades Médicas , España/epidemiología , Evaluación de Síntomas/métodosRESUMEN
Two different sludge retention times (SRTs) were tested in order to assess the impact on membrane fouling and effluent quality in an anaerobic membrane bioreactor (AnMBR). Two up-flow anaerobic sludge bed (UASB) reactors (1 l volume) coupled to external tubular ultrafiltration membranes (filtration area = 81 cm(2)) were operated at a hydraulic retention time of 3 h and two different SRTs (100 and 60 days). The transmembrane pressure (TMP), flux (J) and relevant parameters to assess water quality were measured. Effluents from UASB reactors were filtered for 500 h without intermediate cleaning. The permeate met Mexican standards for wastewater reclamation in both tested conditions. Abrupt and periodical changes in the TMP and J were noticed during the experimental period. A fouling layer collapse and compression hypothesis was set forth in order to explain these changes. An autopsy performed on biofouled membranes indicated that deposited mass was mainly composed of volatile solids (85%) and the rest related to mineral matter, with the presence of inorganic salts containing Ca, Mg, Fe, P and Si. Biomass in the fouling layer was estimated at 0.27% based on the DNA/biomass ratio for the bacterial biofilm. No clear difference in membrane fouling was detected under the two SRTs applied to the systems. However, when operated over 500 h, repetitive sudden TMP and flux changes occurred later in system A (SRT of 100 days) than in system B (SRT of 60 days) suggesting a stronger fouling layer structure in the former.
Asunto(s)
Incrustaciones Biológicas , Reactores Biológicos/microbiología , Filtros Microporos/microbiología , Aguas del Alcantarillado , Contaminantes del Agua/análisis , Purificación del Agua/métodos , Anaerobiosis , Biomasa , Ciudades , México , Aguas del Alcantarillado/análisis , Aguas del Alcantarillado/microbiología , Ultrafiltración , Purificación del Agua/instrumentaciónRESUMEN
Hereditary susceptibility to pheochromocytoma (PCC) and paraganglioma (PGL) represents a very complex genetic scenario. It has been reported that the absence of familial antecedents of the disease does not preclude the existence of a mutation affecting any of the five major susceptibility genes. In fact, 11-24% of apparently sporadic cases (without familial or syndromic antecedents) harbor an unexpected germline mutation, but we do not know what is happening in "truly apparently" sporadic patients (i.e., apparently sporadic cases diagnosed with only one tumor). In the present study, we have analyzed 135 apparently sporadic patients developing a single tumor for the five major susceptibility genes: VHL, RET, SDHB, SDHC, and SDHD. Fourteen percent of cases were found to harbor a germline mutation, and only 2.2% of patients were older than 45 years at onset. By taking into account the tumor location and a threshold age at onset of 45 years, we propose a rational scheme for genetic testing. Analyzing VHL and RET genes would be recommended only in young patients developing a single PCC. On the other hand, genetic testing of SDHD should be done in all patients developing an extra-adrenal tumor before the age of 45, and SDHC could be the responsible gene in cases developing a single head and neck tumor, independently of age. Finally, the analysis of SDHB should always be performed because of its association to malignancy and the low penetrance of mutations affecting this gene.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/genética , Pruebas Genéticas , Paraganglioma/genética , Feocromocitoma/genética , Adolescente , Neoplasias de las Glándulas Suprarrenales/diagnóstico , Adulto , Anciano , Femenino , Mutación de Línea Germinal , Humanos , Masculino , Persona de Mediana Edad , Paraganglioma/diagnóstico , Feocromocitoma/diagnóstico , Proteínas Proto-Oncogénicas c-ret/genética , Succinato Deshidrogenasa/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética , Adulto JovenRESUMEN
BACKGROUND: Hereditary susceptibility to familial paraganglioma syndromes is mainly due to mutations in one of six genes, including three of the four genes encoding the subunits of the mitochondrial succinate dehydrogenase complex II. Although prevalence, penetrance and clinical characteristics of patients carrying point mutations affecting the genes encoding succinate dehydrogenase have been well studied, little is known regarding these clinical features in patients with gross deletions. Recently, we found two unrelated Spanish families carrying the previously reported SDHB exon 1 deletion, and suggested that this chromosomal region could be a hotspot deletion area. METHODS: We present the molecular characterisation of this apparently prevalent mutation in three new families, and discuss whether this recurrent mutation is due either to the presence of a founder effect or to a hotspot. RESULTS: The breakpoint analysis showed that all Iberian Peninsular families described harbour the same exon 1 deletion, and that a different breakpoint junction segregates in an affected French pedigree. CONCLUSIONS: After haplotyping the SDHB region, we concluded that the deletion detected in Iberian Peninsular people is probably due to a founder effect. Regarding the clinical characteristics of patients with this alteration, it seems that the presence of gross deletions rather than point mutations is more likely related to abdominal presentations and younger age at onset. Moreover, we found for the first time a patient with neuroblastoma and a germline SDHB deletion, but it seems that this paediatric neoplasia in a pheochromocytoma family is not a key component of this disease.
Asunto(s)
Proteínas Hierro-Azufre/genética , Síndromes Neoplásicos Hereditarios/genética , Paraganglioma/genética , Eliminación de Secuencia , Succinato Deshidrogenasa/genética , Adolescente , Adulto , Secuencia de Bases , Niño , Cartilla de ADN/genética , Exones , Femenino , Efecto Fundador , Haplotipos , Humanos , Masculino , Síndromes Neoplásicos Hereditarios/enzimología , Paraganglioma/enzimología , Reacción en Cadena de la Polimerasa , Polimorfismo de Nucleótido Simple , EspañaRESUMEN
Primary infection of legumes by rhizobia involves the controlled localized enzymatic breakdown of cell walls at root hair tips. Previous studies determined the role of rhizobial CelC2 cellulase in different steps of the symbiotic interaction Rhizobium leguminosarum-Trifolium repens. Recent findings also showed that CelC2 influences early signalling events in the Ensifer meliloti-Medicago truncatula interaction. Here, we have monitored the root hair phenotypes of two legume plants, T. repens and M. sativa, upon inoculation with strains of their cognate and non-cognate rhizobial species, R. leguminosarum bv trifolii and E. meliloti, (over)expressing the CelC2 coding gene, celC. Regardless of the host, CelC2 specifically elicited 'hole-on-the-tip' events (Hot phenotype) in the root hair apex, consistent with the role of this endoglucanase in eroding the noncrystalline cellulose found in polarly growing cell walls. Overproduction of CelC2 also increased root hair tip redirections (RaT phenotype) events in both cognate and non-cognate hosts. Interestingly, heterologous celC expression also induced non-canonical alterations in ROS (Reactive Oxygen Species) homeostasis at root hair tips of Trifolium and Medicago. These results suggest the concurrence of shared unspecific and host-related plant responses to CelC2 during early steps of symbiotic rhizobial infection. Our data thus identify CelC2 cellulase as an important determinant of events underlying early infection of the legume host by rhizobia.
Asunto(s)
Celulasa/metabolismo , Fabaceae/metabolismo , Fabaceae/microbiología , Interacciones Huésped-Patógeno/fisiología , Rhizobium leguminosarum/metabolismo , Simbiosis/fisiología , Pared Celular/metabolismo , Pared Celular/microbiología , Infecciones por Bacterias Gramnegativas/microbiología , Medicago truncatula/metabolismo , Medicago truncatula/microbiología , Fenotipo , Raíces de Plantas/metabolismo , Raíces de Plantas/microbiología , Nódulos de las Raíces de las Plantas/metabolismo , Nódulos de las Raíces de las Plantas/microbiología , Trifolium/metabolismo , Trifolium/microbiologíaRESUMEN
Cytochrome P450 2C8 (CYP2C8) plays a major role in the metabolism of therapeutically important drugs which exhibit large interindividual differences in their pharmacokinetics. In order to evaluate any genetic influence on this variation, a CYP2C8 phenotype-genotype evaluation was carried out in Caucasians. Two novel CYP2C8 haplotypes, named B and C with frequencies of 24 and 22% in Caucasians, respectively, were identified and caused a significantly increased and reduced paclitaxel 6alpha-hydroxylation, respectively, as evident from analyses of 49 human liver samples. In healthy white subjects, CYP2C8*3 and the two novel haplotypes significantly influenced repaglinide pharmacokinetics in SLCO1B1c.521T/C heterozygous individuals: haplotype B was associated with reduced and haplotype C with increased repaglinide AUC (0-infinity). Functional studies suggested -271C>A (CYP2C8*1B) as a causative SNP in haplotype B. In conclusion, two novel common CYP2C8 haplotypes were identified and significantly associated with altered rate of CYP2C8-dependent drug metabolism in vitro and in vivo.
Asunto(s)
Hidrocarburo de Aril Hidroxilasas/genética , Carbamatos/metabolismo , Haplotipos/genética , Paclitaxel/metabolismo , Piperidinas/metabolismo , Hidrocarburo de Aril Hidroxilasas/metabolismo , Hidrocarburo de Aril Hidroxilasas/fisiología , Carbamatos/farmacología , Citocromo P-450 CYP2C8 , Variación Genética/efectos de los fármacos , Variación Genética/genética , Haplotipos/efectos de los fármacos , Humanos , Paclitaxel/farmacología , Piperidinas/farmacología , Población Blanca/genéticaRESUMEN
A descriptive retrospective study was carried out to describe an epidemic outbreak of enteroviral meningitis in Misiones. We reviewed records of 143 children from 1 month to 14 years of age who were hospitalized with aseptic meningitis in the Pediatric Hospital of Posadas from August to December 2005. Increased number of cases was observed between weeks 33 to 50 which reached a maximum peak in weeks 47 and 48, confirming an outbreak. The median of age was 8 years old, 55.2% were males. Eighty percent of cases were in 5 to 14 years old children. The average length of time spent in the hospital was 4.5+/-1.7 days, no deaths were reported. We performed cell counts, chemical and bacterial studies of CSF, and culture or RT-Nested/PCR for enteroviruses. Isolates were serotyped by RT-PCR amplification and genetic sequencing. Cell counts were from 6 to 5040 cells/mm3. Ninety two percent had less than 500 cells/mm3 and 43.5% had lymphocyte predominance. Glucose levels were normal with slightly elevated protein counts in 56% of cases. Of the cultured samples, 28% (17/60) showed cytopathic effect compatible with enterovirus. RT-n-PCR detected enterovirus in 73% (43/59) of the analyzed CSF. Echovirus type 4 was identified in 6 of them. The positive indicator obtained by combining both techniques was 83% (58/70).
Asunto(s)
Brotes de Enfermedades , Infecciones por Echovirus/epidemiología , Meningitis Viral/epidemiología , Adolescente , Argentina/epidemiología , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Estudios RetrospectivosRESUMEN
Hybrid bionanocomposites based on cellulose matrix, with silica nanoparticles as reinforcers, were prepared by one-pot synthesis of cellulose surface modified by solvent exchange method to keep the biopolymer net void for hosting inorganic nanoparticles. Neither expensive inorganic-particle precursors nor crosslinker agents or catalysts were used for effective dispersion of reinforcer concentration up to 50 wt %. Scanning electron microscopy of the nanocomposites shows homogeneous dispersion of reinforcers in the surface modified cellulose matrix. The FTIR spectra demonstrated the cellulose features even at 50 weight percent content of silica nanoparticles. Such a high content of silica provides high thermal stability to composites, as seen by TGA-DSC. The fungi decay resistance to Trametes versicolor was measured by standard test showing good resistance even with no addition of antifungal agents. This one-pot synthesis of biobased hybrid materials represents an excellent way for industrial production of high performance materials, with a high content of inorganic nanoparticles, for a wide variety of applications.
RESUMEN
Testosterone is essential for the growth and function of the luminal prostate cells, but it is also critical for the development of prostate cancer, which in the majority of the cases derives from luminal cells. Cytochrome P450 3A (CYP3A) enzymes hydroxylate testosterone and dehydroepiandrosterone to less active metabolites, which might be the basis for the association between CYP3A polymorphisms and prostate cancer. However, it is unknown whether the CYP3A enzymes are expressed at relevant levels in the prostate and which polymorphisms could affect this tissue-specific CYP3A activity. Thus, we measured CYP3A4, CYP3A5, CYP3A7, and CYP3A43 mRNA in 14 benign prostatic hyperplasias and ten matched non-tumoral/tumoral prostate samples. We found that CYP3A5 mRNA in non-tumoral prostate tissue was 10% of the average amount of liver samples, whereas the expression of the other CYP3A genes was much lower. Similarly to liver, CYP3A5*3 polymorphism decreased CYP3A5 mRNA content 13-fold. CYP3A5 protein was detected in non-tumoral prostate microsomes by western blot, and immunohistochemistry (IHC) localized CYP3A5 exclusively in the basolateral prostate cells. In contrast to the normal tissue, IHC and RT-PCR showed that tumoral tissue lacked CYP3A5 expression. In conclusion, prostate basolateral cells express high levels of CYP3A5 which dramatically decrease in tumoral tissue. This finding supports an endogenous function of CYP3A5 related to the metabolism of intra-prostatic androgens and cell growth, and that polymorphisms affecting CYP3A5 activity may result in altered prostate cancer risk and aggressiveness.