530 resultados para 1087


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[s.c.]

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Melan-A specific CD8+ T cells are thought to play an important role against the development of melanoma. Their in vivo expansion is often observed with advanced disease. In recent years, low levels of Melan-A reactive CD8+ T cells have also been found in HLA-A2 healthy donors, but these cells harbor naive characteristics and are thought to be mostly cross-reactive for the Melan-A antigen. Here, we report on a large population of CD8+ T cells reactive for the Melan-A antigen, identified in one donor with no evidence of melanoma. Interestingly, this population is oligoclonal and displays a clear memory phenotype. However, a detailed study of these cells indicated that they are unlikely to be directly specific for melanoma, so that their in vivo expansion may have been driven by an exogenous antigen. Screening of a Melan-A cross-reactive peptide library suggested that these cells may be specific for an epitope derived from a Mycobacterium protein, which would provide a further example of CD8+ T cell cross-reactivity between a pathogen antigen and a tumor antigen. Finally, we discuss potential perspectives regarding the role of such cells in heterologous immunity, by influencing the balance between protective immunity and pathology, e.g. in the case of melanoma development.

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The minimum chromosome number of Glomus intraradices was assessed through cloning and sequencing of the highly divergent telomere-associated sequences (TAS) and by pulsed field gel electrophoresis (PFGE). The telomere of G. intraradices, as in other filamentous fungi, consists of TTAGGG repeats, this was confirmed using Bal31 nuclease time course reactions. Telomere length was estimated to be roughly 0.9 kb by Southern blots on genomic DNA and a telomere probe. We have identified six classes of cloned chromosomal termini based on the TAS. An unusually high genetic variation was observed within two of the six TAS classes. To further assess the total number of chromosome termini, we used telomere fingerprinting. Surprisingly, all hybridization patterns showed smears, which demonstrate that TAS are remarkably variable in the G. intraradices genome. These analyses predict the presence of at least three chromosomes in G. intraradices while PFGE showed a pattern of four bands ranging from 1.2 to 1.5 Mb. Taken together, our results indicate that there are at least four chromosomes in G. intraradices but there are probably more. The information on TAS and telomeres in the G. intradicies will be essential for making a physical map of the G. intraradices genome and could provide molecular markers for future studies of genetic variation among nuclei in these multigenomic fungi.

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Aggregating fetal liver cell cultures were tested for their ability to metabolize xenobiotics using ethoxycoumarin-O-deethylase (ECOD), as marker of phase I metabolism, and glutathione S-transferase (GST), as marker for phase II reactions. Significant basal activities, stable over 14 days in culture were measured for both ECOD and GST activities. The prototype cytochrome P450 inducers, 3-methylcholanthrene (3-MC) and phenobarbital (PB), increased ECOD and GST activities reaching an optimum 7 days after culturing, followed by a decline in activity. This decline was partially prevented by 1% dimethyl sulfoxide (DMSO) added chronically to the culture medium. DMSO was also found to induce ECOD activity and to a lesser extent GST activity. Furthermore, it potentiated in a dose-dependent manner the induction of ECOD by PB. The food-borne carcinogen 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) is metabolically transformed through a number of pathways in vivo. It was therefore used to examine the metabolic capacity in fetal and adult liver cell aggregates. Metabolism of MeIQx was mainly through N2-conjugation, resulting in formation of the N2-glucuronide and sulfamate conjugates for non-induced fetal liver cells. These metabolites were also found in large amounts in non-induced adult liver cells. Low levels of cytochrome P450-mediated ring-hydroxylated metabolites were detected in both non-induced fetal and adult liver cells. After induction with arochlor (PCB) or 3-MC, the major pathway was ring-hydroxylation (cytochrome P450 dependent), followed by conjugation to beta-glucuronic or sulfuric acid. The presence of the glucuronide conjugate of N-hydroxy-MeIQx, a mutagenic metabolite, suggested an induction of P450 CYP1A2. The metabolism of MeIQx by liver cell aggregates is very similar to that observed in vivo and suggests that aggregating liver cell cultures are a useful model for in vitro metabolic studies in toxicology.

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В статье будут рассмотрены два исследования русского и советского лингвиста Е.Д. Поливанова, посвященные фонетике «интеллигентского языка». В начале 1930-ч гг. Поливанов выдвинул новаторскую теорию языка, основанную на изучении социолектов и групповых диалектов русского языка современности. Язык интеллигенции - один из излюбленных предметов исследований лингвиста. Поливанов доказывает, что изменениям подвержен не только словарный запас, но и фонетика, и приводит конкретные примеры фонетических изменений, вызванных революцией.

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The genes involved in the biosynthesis of biotin were identified in the hyphal fungus Aspergillus nidulans through homology searches and complementation of Escherichia coli biotin-auxotrophic mutants. Whereas the 7,8-diaminopelargonic acid synthase and dethiobiotin synthetase are encoded by distinct genes in bacteria and the yeast Saccharomyces cerevisiae, both activities are performed in A. nidulans by a single enzyme, encoded by the bifunctional gene bioDA. Such a bifunctional bioDA gene is a genetic feature common to numerous members of the ascomycete filamentous fungi and basidiomycetes, as well as in plants and oömycota. However, unlike in other eukaryota, the three bio genes contributing to the four enzymatic steps from pimeloyl-CoA to biotin are organized in a gene cluster in pezizomycotina. The A. nidulans auxotrophic mutants biA1, biA2 and biA3 were all found to have mutations in the 7,8-diaminopelargonic acid synthase domain of the bioDA gene. Although biotin auxotrophy is an inconvenient marker in classical genetic manipulations due to cross-feeding of biotin, transformation of the biA1 mutant with the bioDA gene from either A. nidulans or Aspergillus fumigatus led to the recovery of well-defined biotin-prototrophic colonies. The usefulness of bioDA gene as a novel and robust transformation marker was demonstrated in co-transformation experiments with a green fluorescent protein reporter, and in the efficient deletion of the laccase (yA) gene via homologous recombination in a mutant lacking non-homologous end-joining activity.

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A partir de la creació i aplicació didàctica d'una WebQuest en un curs de 4t de Primària s'analitza com i de uina manera pot influir positivament en el rendiment personal i acadèmic del grup d'alumnes, grup que presenta unes característiques acusades de dificultats d'atenció generalitzada, forts desnivells de coneixements, i en el qual es troben alumnes amb necessitats educatives especials (n.e.e.). Les webquest poden ser un bon recurs didàctic per a motivar el treball cooperatiu i la interacció entre alumnes, professors i les tecnologies de la informació i la comunicació.

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A 45-year-old woman with personal history of hypertension presented with an erythematous lesion in the neckline for a year and with a progressive growth. A physical examination revealed an annular lesion with erythematous papules in the edge. Histological exam showed phagocytosis of elastic fibers by multinucleated cells compatible with annular elastolytic giant-cell granuloma. The patient did not present any other associated systemic manifestation. Treatment with tacrolimus 0.1 percent ointment was prescribed with a very good response after two months.

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The genome size, complexity, and ploidy of the arbuscular mycorrhizal fungus (AMF) Glomus intraradices was determined using flow cytometry, reassociation kinetics, and genomic reconstruction. Nuclei of G. intraradices from in vitro culture, were analyzed by flow cytometry. The estimated average length of DNA per nucleus was 14.07+/-3.52 Mb. Reassociation kinetics on G. intraradices DNA indicated a haploid genome size of approximately 16.54 Mb, comprising 88.36% single copy DNA, 1.59% repetitive DNA, and 10.05% fold-back DNA. To determine ploidy, the DNA content per nucleus measured by flow cytometry was compared with the genome estimate of reassociation kinetics. G. intraradices was found to have a DNA index (DNA per nucleus per haploid genome size) of approximately 0.9, indicating that it is haploid. Genomic DNA of G. intraradices was also analyzed by genomic reconstruction using four genes (Malate synthase, RecA, Rad32, and Hsp88). Because we used flow cytometry and reassociation kinetics to reveal the genome size of G. intraradices and show that it is haploid, then a similar value for genome size should be found when using genomic reconstruction as long as the genes studied are single copy. The average genome size estimate was 15.74+/-1.69 Mb indicating that these four genes are single copy per haploid genome and per nucleus of G. intraradices. Our results show that the genome size of G. intraradices is much smaller than estimates of other AMF and that the unusually high within-spore genetic variation that is seen in this fungus cannot be due to high ploidy.

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PURPOSE: The objective of this study was to investigate the additional burdens in terms of pain, prolongation of surgery and morbidity which is added to elective caesarean section if umbilical hernia suture repair is performed simultaneously. Secondly, patient's satisfaction and hernia recurrence rate were assessed. METHODS: Consecutive women with symptomatic umbilical hernia undergoing internal or external suture repair during elective caesarean were included in this retrospective cohort-control study. Data on post-operative pain, duration of surgery and morbidity of a combined procedure were collected. These patients were matched 1:10 to women undergoing caesarean section only. Additionally, two subgroups were assessed separately: external and internal suture hernia repair. These subgroups were compared for patient's satisfaction, cosmesis, body image and recurrence rate. RESULTS: Fourteen patients with a mean age of 37 years were analysed. Internal suture repair (n = 7) prolonged caesarean section by 20 min (p = 0.001) and external suture repair (n = 7) by 34 min (p < 0.0001). Suture repair did not increase morphine use (0.38 ± 0.2 vs. 0.4 ± 02 mg/kg body weight), had no procedure-related morbidity and prolonged hospitalization by 0.5 days (p = 0.01). At a median follow-up of 37 (5-125) months, two recurrences in each surgical technique, internal and external suture repair, occurred (28 %). Body image and cosmesis score showed a higher level of functioning in internal suture repair (p = 0.02; p = 0.04). DISCUSSION: Despite a high recurrence rate, internal suture repair of a symptomatic umbilical hernia during elective caesarean section should be offered to women if requested. No additional morbidity or scar is added to caesarean section. Internal repair is faster, and cosmetic results are better, additional skin or fascia dissection is avoided, and it seems to be as effective as an external approach. Yet, women must be informed on the high recurrence rate.

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A 54-year-old woman presented a peri-areolar nodule located in the skin of the right breast. Clinical examination showed a 6 x 5 cm exophytic, lobed, ulcerated, and bleeding nodule. The patient reported that the tumor had grown gradually over a period of 3 months. The patient had been diagnosed 8 years prior to presentation with infiltrating ductal carcinoma of the right breast (pT2NO). This tumor was treated with partial mastectomy (conservative surgery) and lymph node dissection, then subsequently received 30 tangent field radiotherapy sessions to the breast for a total dose of 45 Gy. The rest of her cutaneous exam was normal. There was no family history of any similar tumor.