35 research outputs found
Virus Chikungunya, una infección emergente
El virus Chikungunya (CHIKV) es un Alphavirus de la familia Togaviridae que se transmite por la picadura de mosquitos del género Aedes. Inicialmente CHIKV se aisló en Tanzania. En la última década ha experimentado una importante diseminación mundial en forma de brotes esporádicos, siendo muy llamativa la magnitud del actual brote en la región de las Américas y su aparición, tanto importada como autóctona, en regiones templadas. La infección se manifiesta con síntomas inespecíficos autolimitados que se acompañan de dolor articular. Característicamente estas artralgias pueden llegar a ser crónicas e invalidantes. De momento no se dispone de tratamiento ni vacunas específicas para esta enfermedad, siendo su prevención, mediante el control del vector, la principal medida de contención. Su diagnóstico se basa en la determinación del virus mediante técnicas moleculares, cultivos celulares y la detección de la respuesta inmune por técnicas serológicas. En este artículo se revisan los conocimientos e investigaciones más relevantes en cuanto al CHIKV, su vector, la clínica y patogénesis de la enfermedad, los métodos diagnósticos y los últimos avances en tratamiento y prevención
Osteopoiquilosis.: a propósito de tres casos
Los autores presentan el estudio genealógico, clínico y radiológico de
una familia con osteopoiquilosis, haciendo hincapié en el diagnóstico
diferencial así como en la importancia de la biopsia en el caso de sospecha
de una tumoración ósea.The authors show a genealogic, clinic and radiologic study of
one family affected by osteopoikilosis. They emphasiz e the differential
diagnosis as well as the importance of biopsy suspecting a
bone tumor
Functional Analysis of the Phycomyces carRA Gene Encoding the Enzymes Phytoene Synthase and Lycopene Cyclase
Phycomyces carRA gene encodes a protein with two domains. Domain R is characterized by red carR mutants that accumulate lycopene. Domain A is characterized by white carA mutants that do not accumulate significant amounts of carotenoids. The carRA-encoded protein was identified as the lycopene cyclase and phytoene synthase enzyme by sequence homology with other proteins. However, no direct data showing the function of this protein have been reported so far. Different Mucor circinelloides mutants altered at the phytoene synthase, the lycopene cyclase or both activities were transformed with the Phycomyces carRA gene. Fully transcribed carRA mRNA molecules were detected by Northern assays in the transformants and the correct processing of the carRA messenger was verified by RT-PCR. These results showed that Phycomyces carRA gene was correctly expressed in Mucor. Carotenoids analysis in these transformants showed the presence of ß-carotene, absent in the untransformed strains, providing functional evidence that the Phycomyces carRA gene complements the M. circinelloides mutations. Co-transformation of the carRA cDNA in E. coli with different combinations of the carotenoid structural genes from Erwinia uredovora was also performed. Newly formed carotenoids were accumulated showing that the Phycomyces CarRA protein does contain lycopene cyclase and phytoene synthase activities. The heterologous expression of the carRA gene and the functional complementation of the mentioned activities are not very efficient in E. coli. However, the simultaneous presence of both carRA and carB gene products from Phycomyces increases the efficiency of these enzymes, presumably due to an interaction mechanism
Expansion of Signal Transduction Pathways in Fungi by Extensive Genome Duplication
International audienceno abstrac
Population-based multicase-control study in common tumors in Spain (MCC-Spain): rationale and study design
Introduction: We present the protocol of a large population-based case-control study of 5 common tumors
in Spain (MCC-Spain) that evaluates environmental exposures and genetic factors.
Methods: Between 2008-2013, 10,183 persons aged 20-85 years were enrolled in 23 hospitals and primary
care centres in 12 Spanish provinces including 1,115 cases of a new diagnosis of prostate cancer,
1,750 of breast cancer, 2,171 of colorectal cancer, 492 of gastro-oesophageal cancer, 554 cases of chronic
lymphocytic leukaemia (CLL) and 4,101 population-based controls matched by frequency to cases by age,
sex and region of residence. Participation rates ranged from 57% (stomach cancer) to 87% (CLL cases) and
from 30% to 77% in controls. Participants completed a face-to-face computerized interview on sociodemographic
factors, environmental exposures, occupation, medication, lifestyle, and personal and family
medical history. In addition, participants completed a self-administered food-frequency questionnaire
and telephone interviews. Blood samples were collected from 76% of participants while saliva samples
were collected in CLL cases and participants refusing blood extractions. Clinical information was recorded
for cases and paraffin blocks and/or fresh tumor samples are available in most collaborating hospitals.
Genotyping was done through an exome array enriched with genetic markers in specific pathways. Multiple
analyses are planned to assess the association of environmental, personal and genetic risk factors
for each tumor and to identify pleiotropic effects.
Discussion: This study, conducted within the Spanish Consortium for Biomedical Research in Epidemiology
& Public Health (CIBERESP), is a unique initiative to evaluate etiological factors for common cancers
and will promote cancer research and prevention in Spain.The study was partially funded by the “Accion Transversal
del Cancer”, approved on the Spanish Ministry Council on the
11th October 2007, by the Instituto de Salud Carlos III-FEDER
(PI08/1770, PI08/0533, PI08/1359, PS09/00773, PS09/01286,
PS09/01903, PS09/02078, PS09/01662, PI11/01403, PI11/01889,
PI11/00226, PI11/01810, PI11/02213, PI12/00488, PI12/00265,
PI12/01270, PI12/00715, PI12/00150), by the Fundación Marqués
de Valdecilla (API 10/09), by the ICGC International Cancer Genome
Consortium CLL, by the Junta de Castilla y León (LE22A10-2), by
the Consejería de Salud of the Junta de Andalucía (PI-0571), by the
Conselleria de Sanitat of the Generalitat Valenciana (AP 061/10),
by the Recercaixa (2010ACUP 00310), by the Regional Government
of the Basque Country by European Commission grants FOOD-CT-
2006-036224-HIWATE, by the Spanish Association Against Cancer
(AECC) Scientific Foundation, by the The Catalan Government
DURSI grant 2009SGR1489
Interallelic complementation provides genetic evidence for the multimeric organization of the Phycomyces blakesleeanus phytoene dehydrogenase.
The Phycomyces blakesleeanus wild-type is yellow, because it accumulates beta-carotene as the main carotenoid. A new carotenoid mutant of this fungus (A486) was isolated, after treatment with ethyl methane sulfonate (EMS), showing a whitish coloration. It accumulates large amounts of phytoene, small quantities of phytofluene, zeta-carotene and neurosporene, in decreasing amounts, and traces of beta-carotene. This phenotype indicates that it carries a leaky mutation affecting the enzyme phytoene dehydrogenase (EC 1.3.-.-), which is specified by the gene carB. Biochemical analysis of heterokaryons showed that mutant A486 complements two previously characterized carB mutants, C5 (carB10) and S442 (carB401). Sequence analysis of the carB gene genomic copy from these three strains revealed that they are all altered in the gene carB, giving information about the nature of the mutation in each carB mutant allele. The interallelic complementation provides evidence for the multimeric organization of the P. blakesleeanus phytoene dehydrogenase
Double-stranded RNA and virus-like particles in the grass endophyte Epichloe festucae
Two double-stranded ribonucleic acid (dsRNA) elements were detected in an isolate of the clavicipitaceous grass endophyte Epichloe festucae obtained from an asymptomatic Festuca rubra plant. No dsRNA was detected in three other isolates of E. festucae. The size of the two dsRNA elements isolated from mycelium was of 5.2 and 3.2 kbp. Hybridization experiments with a cDNA probe complementary to the 5.2 kbp dsRNA showed that there was no sequence similarity between the dsRNA elements. Isometric virus-like particles of about 50 nm in diameter were observed by electron microscopy in sucrose-gradient purified virus preparations from the isolate containing dsRNA. The 5.2 khp dsRNA element was present in the partially purified virus preparations, suggesting that this element is encapsidated. There was no difference with respect to growth rate or colony morphology between the dsRNA containing and dsRNA-free isolates. The presence of dsRNA and virus-like particles suggests the presence of a mycovirus in the Vit5 strain of E. festucae.This study was financed by the Spanish government research grants MAPA SC95-002-C2-1 and CICYT AGF96-0423 ; and a postdoctoral fellowship from INIA