Evaluation of the XRCC1 gene as a phenotypic modifier in BRCA1/2 mutation carriers. Results from the consortium of investigators of modifiers of BRCA1/BRCA2

BACKGROUND

Single-nucleotide polymorphisms (SNPs) in genes involved in DNA repair are good candidates to be tested as phenotypic modifiers for carriers of mutations in the high-risk susceptibility genes BRCA1 and BRCA2. The base excision repair (BER) pathway could be particularly interesting given the relation of synthetic lethality that exists between one of the components of the pathway, PARP1, and both BRCA1 and BRCA2. In this study, we have evaluated the XRCC1 gene that participates in the BER pathway, as phenotypic modifier of BRCA1 and BRCA2.

METHODS

Three common SNPs in the gene, c.-77C>T (rs3213245) p.Arg280His (rs25489) and p.Gln399Arg (rs25487) were analysed in a series of 701 BRCA1 and 576 BRCA2 mutation carriers.

RESULTS

An association was observed between p.Arg280His-rs25489 and breast cancer risk for BRCA2 mutation carriers, with rare homozygotes at increased risk relative to common homozygotes (hazard ratio: 22.3, 95% confidence interval: 14.3-34, P<0.001). This association was further tested in a second series of 4480 BRCA1 and 3016 BRCA2 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1 and BRCA2.

CONCLUSIONS AND INTERPRETATION

No evidence of association was found when the larger series was analysed which lead us to conclude that none of the three SNPs are significant modifiers of breast cancer risk for mutation carriers.

Plant phenology, growth and nutritive quality of Briza maxima: responses induced by enhanced ozone atmospheric levels and nitrogen enrichment

An assessment of the effects of tropospheric ozone (O(3)) levels and substrate nitrogen (N) supplementation, singly and in combination, on phenology, growth and nutritive quality of Briza maxima was carried out. Two serial experiments were developed in Open-Top Chambers (OTC) using three O(3) and three N levels. Increased O(3) exposure did not affect the biomass-related parameters, but enhanced senescence, increased fiber foliar content (especially lignin concentration) and reduced plant life span; these effects were related to senescence acceleration induced by the pollutant. Added N increased plant biomass production and improved nutritive quality by decreasing foliar fiber concentration. Interestingly, the effects of N supplementation depended on meteorological conditions and plant physiological activity. N supplementation counteracted the O(3)-induced senescence but did not modify the effects on nutritive quality. Nutritive quality and phenology should be considered in new definitions of the O(3) limits for the protection of herbaceous vegetation.

Pre–release training of juvenile little owls Athene noctua to avoid predation

Anti–predator training of juvenile little owls was tested in a sample of recovered owls raised in captivity in Brinzal Owl Rescue Center (Madrid, Spain). Mortality caused by predators has been described previously in released individuals. Nine little owls were conditioned during their development to a naturalized goshawk and a large live rat, whose presence was paired to the owl’s alarm call. All nine owls and seven non–trained individuals were then released during the late summer and autumn and radio–tracked for six weeks to test their survival. In total 71.4% of the trained owls survived while only the 33.3% of the untrained group were alive at the end of week six. The only cause of death that was detected was predation. Antipredator training, therefore, seems to be beneficial in maximizing survival after the release of juvenile little owls.

Association between multiple sclerosis and Candida species: evidence from a case-control study

Candida infection among multiple sclerosis (MS) patients has not been studied in depth. We determined whether there is an association between serological evidence of Candida infection and MS. Blood specimens were obtained from 80 MS patients and 240 matched controls. Immunofluorescence analysis and ELISA were used to detect Candida species antibodies and slot-blot to detect antigens. Using immunofluorescence analysis, moderate to high concentrations of serum antibodies to Candida famata were present in 30 (37.5%) MS patients vs. 30 (12.5%) controls (p < 0.001). Results for Candida albicans were 47.5% (38/80) in MS patients vs. 21.3% (51/240) in controls (p < 0.001), for Candida parapsilosis 37% (28/80) vs. 17.1% (41/240) (p < 0.001) and for Candida glabrata 46.3% (37/80) vs. 17.5% (42/240) (p < 0.001), respectively. After adjusting for age and gender, the odds ratios (95% confidence intervals) for MS, according to the presence of Candida antigens were: 2.8 (0.3-23.1, p = 0.337) for Candida famata; 1.5 (0.7-3.4, p = 0.290) for Candida albicans; 7.3 (3.2-16.6, p < 0.001) for Candida parapsilosis; and 3.0 (1.5-6.1, p = 0.002) for Candida glabrata. The results were similar after excluding ten patients on immunosuppressants. The results of this single study suggest that Candida species infection may be associated with increased odds of MS.

Cell death targeting therapies in B lymphoid malignancies

Programmed cell death, commonly associated with the term apoptosis, is an integrated intracellular program that plays a critical role in lymphoid tissue homeostasis. Alterations in this highly regulated process is a common feature of most lymphoid malignancies, thus facilitating tumor escape from traditional chemotherapeutic agents whose main endpoint is the induction of tumor cell death. In the last years, enormous progress has been made in understanding the deregulated signals that could lead to ineffective apoptosis in B lymphoid tumors. Consequently, several new strategies have been designed to modulate the key molecules of life-and-death decisions. Numerous novel approaches are being validated and some of them have progressed to clinical testing or have even been approved in a record time. In this review we will focus on current therapies that have demonstrated to trigger efficiently cell death in B lymphoid neoplasms, either by directly targeting the intracellular apoptotic machinery or by modulating different factors involved in its regulation.

A CFSE-based assay of proliferative response of lymphocytes to stimulation with dengue viruses

Dengue viruses (DENVs) are human pathogens that constitute a significant threat worldwide. Since they up-regulate MHC class I molecules; the cell-mediated immunity may play an important role in the defense against viruses. In this work, we tested a CFSE-based assay in determining proliferative response of lymphocytes isolated from mice or monkeys previously immunized with various DENV antigens to in vitro stimulation with DENVs. A positive proliferative response was obtained with lymphocytes of animals immunized with either live DENV-2 or its recombinant proteins. A similar result was also obtained with CD8+ T cells from mice immunized with live DENV-1 or DENV-2 following stimulation with homologous viruses. A comparison of the carboxyfluorescein diacetate succinimidyl ester (CFSE)-based and a 3H-thymidine incorporation-based assays of proliferative response of total lymphocytes showed a fair correlation of results of both assays. However, the CSFE-based assay offers in addition the determination of contribution of the CD8+ or other subsets of T cells to total proliferative response. These results represent the first and successful application of a CFSE-based assay to the evaluation of cell-mediated immunity to DENVs. This assay might be also exploited in testing candidate DENV vaccines.

Decline in the workload associated with the serodiagnosis of syphilis in a general hospital: 1994-2004

Syphilis re-emergence is a cause of concern. Our objective was to quantify the laboratory workload, incident cases and patient follow-up that syphilis has generated for 11 years in a large teaching hospital. An ecologic study including all samples submitted for syphilis serodiagnosis at our hospital from January 1994 to December 2004 was undertaken. Our laboratory processed 58,832 samples for syphilis serodiagnosis. From 1994 to 2004, the number of samples submitted for syphilis testing dropped by 11% (95% confidence interval [CI] 10-12, p<0.001). Syphilis was diagnosed in 443 patients. The incidences were 11, 3 and 8 per 100,000 inhabitants/year in 1994, 2000 and 2004, respectively. Only 42% (185) of patients had repeat tests and in 79% (146) of cases, the 1-year follow-up data were missing. The median follow-up was 9 months (interquartile range [IQR] 3-26). We detected a reduction in the effort to detect syphilis, despite an increase in its incidence and the low cost of syphilis screening. Efforts should be intensified to improve physician compliance with syphilis screening and follow-up guidelines.

Molecular characterization of the hemagglutinin-neuraminidase gene of porcine rubulavirus isolates associated with neurological disorders in fattening and adult pigs

"Blue eye disease" is a viral infection of swine endemic in Mexico, which produces fatal encephalitis accompanied by respiratory signs and corneal opacity in suckling piglets. An atypical blue eye disease outbreak presented high rates of neurological signs in fattening and adult pigs from 2000 to 2003. In order to identify the basis of increased neurovirulence, the hemagglutinin-neuraminidase (HN) gene of several porcine rubulavirus isolates were sequenced and compared with that of La Piedad Michoacan virus and other isolates that did not produce neurological disorders in weaned pigs. Nine amino acid mutations distinguished the high neurovirulent PAC6-PAC9 viruses, whereas five mutations characterized the low neurovirulent PAC2 and PAC3 viruses. HN protein three-dimensional models showed that the main conformation and functional domains were preserved, although substitutions A223T and A291D occurred in PAC2 and PAC3 viruses, as well as A511K and E514K presented in PAC6-PAC9 viruses considerably modified the properties of the HN protein surface. The increased positive charge of the HN protein of PAC6-PAC9 viruses seems to be associated with their increased neurovirulence.

Breast cancer experience in Uruguay: A 21-year follow up of 1,906 patients in the same institution

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Background: Breast cancer is the most common tumor arising in Uruguaian women accounting for 1,930 patients/year (adjusted incidence ratio 83.1/100,000) with 637 death/year (adjusted mortality ratio 24.1/100,000). Both incidence and mortality rank Uruguay at the top of the latinamerican countries ( IARC-GloboCan 2002). We are presenting our final results with 1,906 patients followed during a 21 year period in the biggest private Institution in our country (CENDIMA) and probably amongst all other latin-american countries. Methods: Although this study was initially designed to find a relationship between prognostic factors and survival parameters: OS (overall survival) and DFS (disease free survival) it also describes the epidemiological features of a big breast cancer population in the top ranked country for breast cancer incidence and mortality in Latin America. Statistical analysis was calculated with SPSS (11.0 version) and SAS (6.0 version) programs. OS and DFS results were obtained through Kaplan Meier method. Log rank test was implemented for univariate analysis and Cox proportional hazard rates were used for multivariate analysis. Results: The median age at diagnosis was 61.0 (SD 13.5). Ductal infiltrating carcinoma (DIC) accounted for more than 80% of patients and 56% were node negative (N0) patients at diagnosis. Stratification was: Stage 0: 8.6%, Stage I: 31.5%, Stage II: 41.8%, Stage III: 16.6%, Stage IV: 1.5%. For OS, the axillary status and hystologic grade showed the highest relative ratio (RR) value: 2.49 and 2.40. The nodal status was the main prognostic factor related to DFS with a 2.2 RR. The five and ten year survival rate was: 0.96 and 0.92 (stage I), 0.84 and 0.71 (stage II), 0.71 and 0.56 (stage III) and 0.39 and 0.29 (stage IV) respectively. Conclusions: This is the final analysis of our population in Uruguay representing the biggest report in breast pathology in a latin-american country with a long follow up period (more than 20 years). Our “good” survival results may reflect the initially low risk population at diagnosis (56% node negative, 40.1% stage 0-I ). Nodal status, histologic grade and staging at diagnosis were independent prognostic factors in univariate and multivariate analysis.

No significant financial relationships to disclose.

Immunohistochemical localization of hormones and peptides in the human pituitary cells in a case of hypercortisolism by ACTH secreting microadenoma

This study assesses the action of hypercortisolism on the hormone and peptide periadenoma region of removed ACTH-producing microadenoma. Our findings show that cortisol excess affects both ACTH and GH production, with no immunoreaction for these hormones. The remaining pituitary hormones (TSH, FSH and PRL) and POMC-derived peptides (betaEnd, alphaMSH and betaMSH) were not modified. Likewise, we observed pituitary immunoreactive cells for Neurotensin (NT), Intestinal vasoactive peptide (VIP), Substance P (SP) and Angiotensin-II (Ang-II). The colocalization demonstrated that NT was expressed in thyrotrope and gonadotrope cells, VIP in gonadotrope cells and SP in corticotrope cells. The results about Ang-II were inconclusive. On the other hand, immunoreaction for the NPY and Gal peptides were not present. In the adenomatous cells, the peptide NT is present in ACTH cells as well as SP. These results suggest a peptide regulation of pituitary cells in the pathological state that can differ between normal and tumoural cells of the same pituitary.