miRQuest: integration of tools on a Web server for microRNA research.

This report describes the miRQuest - a novel middleware available in a Web server that allows the end user to do the miRNA research in a user-friendly way. It is known that there are many prediction tools for microRNA (miRNA) identification that use different programming languages and methods to realize this task. It is difficult to understand each tool and apply it to diverse datasets and organisms available for miRNA analysis. miRQuest can easily be used by biologists and researchers with limited experience with bioinformatics. We built it using the middleware architecture on a Web platform for miRNA research that performs two main functions: i) integration of different miRNA prediction tools for miRNA identification in a user-friendly environment; and ii) comparison of these prediction tools. In both cases, the user provides sequences (in FASTA format) as an input set for the analysis and comparisons. All the tools were selected on the basis of a survey of the literature on the available tools for miRNA prediction. As results, three different cases of use of the tools are also described, where one is the miRNA identification analysis in 30 different species. Finally, miRQuest seems to be a novel and useful tool; and it is freely available for both benchmarking and miRNA identification at http://mirquest.integrativebioinformatics.me/.

Yeast diversity in the oral microbiota of subjects with periodontitis: Candida albicans and Candida dubliniensis colonize the periodontal pockets.

The term periodontitis encompasses several polymicrobial infectious diseases, of multifactorial etiology, with chronic and aggressive forms. In spite of the etiopathogenic differences between these two forms of the disease, few studies have analyzed the subgingival colonization by yeast. The objective of this investigation was to analyze the composition of the yeast microbiota present in the mucosa and subgingival sites of healthy individuals and patients with aggressive and chronic periodontitis. For this, samples were recovered from these two locations and the yeast recovered identified by phenotypic and genotypic methods. Patients with chronic periodontitis showed significant differences in relation to the other groups with respect to carrier status (69.2% versus 35.7% of healthy individuals; [chi(i)(2) test; p=0.014]), the total number of isolated colony forming units or CFU (mean and ranges 281.6 (0-6048) [K-W(2)=6.998; p=0.03]), the Simpson diversity index (I) in site b (I(b)=0.344 versus healthy subjet and aggresive periodontitis where I=0 [multiple t-test comparisons with the Bonferronni correction, p<0.05]), and the species profile. Interestingly, in spite of the varied profiles of the species present in the mucosa of the three groups analyzed we noted that only C. albicans and C. dubliniensis were capable of colonizing the periodontal pockets in patients with chronic periodontitis, while only C. albicans was identified in the subgingiva of healthy individuals and patients with aggressive periodontitis.

Cáncer basocelular en poblaciones expuestas y no expuestas a arsénico / Basal cell carcinoma in arsenic exposed and non exposed population

Se presenta un estudio de incidencia de CBC por exposición a arsénico, entre enero de 1990 y diciembre de 1999. El grupo expuesto está constituído por residentes en Chuquicamata y Calama (provincia de El Loa), operados de CBC en el Hospital de Chuquicamata y el grupo de no expuestos comprende a los residentes en los valles interiores de la IV región (Vicuña, Limari y Choapa). Hubo 247 pacientes en el primer grupo y 205 en el segundo. La radiación UVB en la IV región fue de 1382 erg/cm2/año y de 1556 erg/cm2/año en Calama (12,2 por ciento mayor en ésta). La localización más frecuente del tumor en ambas áreas fue en la cara. En El Loa, el tumor fue más frecuente en áreas no expuestas del cuerpo a UVB en relación a la IV región p=0,0001. La edad media de aparición del tumor fue similar en ambas áreas, p=0,24 y no hay diferencia de incidencia por sexo entre las regiones, p=0,566. La tasa de incidencia en la IV región fluctuó entre 9,1 y 28,9 x 100.000 en los diez años y en la provincia. El Loa fluctúa entre 49,1 y 119,2 x 100.000. El RR para el desarrollo de CBC fue en los diferentes años, entre 3 y 8 veces mayor en la provincia de El Loa. En conclusión, este estudio muestra que existe una fuerte asociación y una probable relación causal entre la exposición a arsénico en suspensión aérea y la aparición de CBC en el área de Chuquicamata y Calama

Development of the sexual reproductive cycle of Xanthophyllomyces dendrorhous.

Conditions inducing the development of holobasidia with terminal basidiospores in wild-type and astaxanthin mutant strains of Xanthophyllomyces dendrorhous were reexamined. Important factors for the development of holobasidia were the incubation temperature and the medium composition. A temperature of 9 degrees C was demonstrated to enhance holobasidia formation. Minimal growth medium with glucose as sole carbon source at concentrations between 80 and 120 mM, and ammonium nitrate with concentrations of 28 mM gave optimal results. A period of 20 or more days was needed for the formation of holobasidia with basidiospores. Additionally, mutant strains of X. dendrorhous were observed to have different abilities to produce holobasidia and strains obtained after protoplast fusion, which have been called fusant in this study, to have an increased capacity to form holobasidia.

Avances en el tratamiento del liquen plano de mucosa oral / Advances in the treatment of the oral lichen planus

El liquen Plano Oral es una patología relativamente frecuente. Su etiología, si bien es desconocida, probablemente corresponda a un fenómeno inmunológico. Clínicamente presenta varias formas, siendo la más frecuente la forma reticular, generalmente asistomática. Las formas erosiva y atrófica pueden presentar gran sintomatología, demandando grandes esfuerzos para realizar un tratamiento lo más eficas posible. Se han ensayado múltiples tratamientos con distintos grados de éxito, no existiendo en la actualidad ninguno que sea efectivo en todos los casos. Como primera línea se recomienda el uso de corticosteroides tópicos en base adhesiva; si no responde a esta terapia o son pacientes muy sintomáticos, se utilizan corticosteroides sistémicos por periodos cortos. Se ha asociado también azatioprina a los corticosteroides sistémicos para disminuir las dosis de éstos. Asimismo, se ha usado ciclosporina A en pacientes muy sintomáticos, con resultados contradictorios; también se han ensayado los retinoides tópicos y orales, siendo efectivos parcialmente y sólo en la forma clínica hipertrófica

Inyección intramuscular de toxina botulínica con fines dermocosmiátricos / Intramuscular injection of botulin toxin for dermocosmetic use

La toxina botulínica producida por el Clostridium botulinum es un potente inhibidor neuromuscular local, altamente específico, que actúa mediante bloqueo de la liberación de acetilcolina en la placa neuromuscular, traduciéndose clínicamente en una parálisis fláccida del músculo tratado. El uso de la toxina botulínica se ha visto incrementado en los últimos años, tanto en clínica como en ciencias básicas, existiendo numerosos estudios que avalan su utilización con fines terapéuticos y de investigación. El propósito de esta revisión es analizar los usos e indicaciones actuales de la toxina botulínica, su aplicación en dermocosmiatría, las diversas técnicas empleadas, precauciones, contraindicaciones y eventuales complicaciones

Complementation analysis with new genetic markers in Phaffia rhodozyma.

Isolation and characterization of auxotrophic mutants from wild-type and astaxanthin mutant strains of Phaffia rhodozyma is described. Differences in survival were observed when u.v. irradiation of P. rhodozyma wild-type and astaxanthin mutant strains were incubated in the dark or exposed to photoreactivating light. Ultra-violet mutagenesis was not effective to produce auxotrophic mutants in this yeast. Auxotrophic mutants were obtained with high efficiency through a nystatin enrichment procedure after a N-methyl-N'-nitro-N-nitrosoguanidine (NGT) mutagenic treatment with a 0.12% survivor level. Stringent mutagenetic conditions were needed to obtain P. rhodozyma auxotrophs. The most frequent mutants were ade- and met- in a rather narrow auxotroph spectrum. These results may be associated with a possible diploid condition of this yeast. The high number of adenine auxotrophs obtained in relation to other auxotrophic mutants suggests the possibility of some degree of heterozygosity in the wild-type strain UCD 67-385.

Genetic transformation of astaxanthin mutants of Phaffia rhodozyma.

Stable red astaxanthin-producing transformants were obtained after genetic transformation of two Phaffia rhodozyma mutants. A yellow mutant, accumulating beta-carotene, and an albino mutant, accumulating phytoene, from P. rhodozyma were transformed using a genomic library of wild-type strain UCD 67-385 in the pBluescript vector. Hybridization assays, using the pBluescript DNA as a radioactive probe, indicate integration of vector sequences into the genome of the transformants. Transformants DNA was digested with restriction endonucleases, ligated with T4 DNA ligase and then used to transform E. coli. Ampicillin resistant plasmids, containing 0.1, 0.2, and 2.5 kb DNA inserts of P. rhodozyma, were rescued from the yeast red transformants. The molecular analysis indicate that transformation has occurred by an integration event of donor DNA into the genome of the host strains.

Genetics and electrophoretic karyotyping of wild-type and astaxanthin mutant strains of Phaffia rhodozyma.

In this work we establish the chromosomal composition of a wild-type, one astaxanthin and two beta-carotene overproducer strains of the red yeast Phaffia rhodozyma. The method used has been pulsed field gel electrophoresis, which has determined 9 DNA chromosomal bands in the yeast genome. The two largest bands are triplets and two other bands, VI and VIII, seem to be doublets. The size of the chromosomal bands varies between 0.35 and 2.5 Mb, suggesting a genome size of 25 Mb. The technique used, complemented with hybridization assays using specific DNA probes, provides direct information about the genomic organization of P. rhodozyma. We have also cloned and located in chromosomal bands different DNA sequences that code for the translation elongation factor 1 alpha (ef-1 alpha), a 7.6 kb BamHI fragment of repetitive DNA (possibly rDNA) and a randomly chosen fragment (named locus R2). Additionally, we have detected a chromosomal length polymorphism between wild-type strains and mutant strains affecting carotenogenesis obtained in our laboratory.