Shorter CAG repeat in the AR gene is associated with atypical hyperplasia and breast carcinoma

Background: Previous reports into the role of [CAG]n repeat lengths in the androgen receptor (AR) gene indicate that these may play an important part in the development and progression of breast cancer, however, knowledge regarding benign breast lesions is limited. Patients and Methods: PCR-based GeneScan analysis was used to investigate the [CAG]n repeat length at exon 1 of the AR gene in 59 benign breast lesions (27 fibroadenomas, 18 atypical hyperplasias, and 14 hyperplasias without atypia) and 54 ductal breast carcinomas. Seventy-two cancer-free women were used as a control group. In addition, [CAG]n repeats were evaluated for the presence of loss of heterozygosity (LOH) and microsatellite instability (MSI) in a subset of these samples (27 fibroadenomas, 14 hyperplasias without atypia and 22 breast carcinomas). Results: Shorter [CAG]n repeat lengths were strongly correlated with atypical hyperplasias (p=0.0209) and carcinomas (p<0.0001). LOH was found in 1/12 and 4/20 informative cases of hyperplasias without atypia and breast carcinomas, respectively. Three patients with breast carcinoma who had previously presented atypical hyperplasia showed a reduction in the [CAG]n repeat length in their carcinomas. Conclusion: Short [CAG]n repeat length (≤20) polymorphisms are strongly associated with breast carcinomas and atypical hyperplasias. Although non-significant, a subgroup of patients with breast carcinoma and genotype SS showed an association with parameters of worse outcome.

Kaposi's sarcoma-associated herpesvirus latency-associated nuclear antigen 1 mimics Epstein-Barr virus EBNA1 immune evasion through central repeat domain effects on protein processing

Kaposi's sarcoma-associated herpesvirus (KSHV/human herpesvirus 8 [HHV8]) and Epstein-Barr virus (EBV/HHV4) are distantly related gammaherpesviruses causing tumors in humans. KSHV latency-associated nuclear antigen 1 (LANA1) is functionally similar to the EBV nuclear antigen-1 (EBNA1) protein expressed during viral latency, although they have no amino acid similarities. EBNA1 escapes cytotoxic lymphocyte (CTL) antigen processing by inhibiting its own proteosomal degradation and retarding its own synthesis to reduce defective ribosomal product processing. We show here that the LANA1 QED-rich central repeat (CR) region, particularly the CR2CR3 subdomain, also retards LANA1 synthesis and markedly enhances LANA1 stability in vitro and in vivo. LANA1 isoforms have half-lives greater than 24 h, and fusion of the LANA1 CR2CR3 domain to a destabilized heterologous protein markedly decreases protein turnover. Unlike EBNA1, the LANA1 CR2CR3 subdomain retards translation regardless of whether it is fused to the 5′ or 3′ end of a heterologous gene construct. Manipulation of sequence order, orientation, and composition of the CR2 and CR3 subdomains suggests that specific peptide sequences rather than RNA structures are responsible for synthesis retardation. Although mechanistic differences exist between LANA1 and EBNA1, the primary structures of both proteins have evolved to minimize provoking CTL immune responses. Simple strategies to eliminate these viral inhibitory regions may markedly improve vaccine effectiveness by maximizing CTL responses. Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Reproductive biology of an endemic Physalaemus of the Brazilian Atlantic forest, and the trade-of between clutch and egg size in terrestrial breeders of the P. signifer group

Physalaemus crombiei is a small foam-nesting frog endemic to the Atlantic forest. It is a member of the P. signifer group known only from its type locality in Santa Teresa, State of Espírito Santo, and from another locality in the State of Bahia, Brazil. Most Physalaemus species are aquatic breeders, and species in the P. signifer group are the only ones exhibiting a tendency toward terrestrial reproduction in the genus. Here we describe the reproductive period, breeding site and reproductive modes of P. crombiei from a third population in the Atlantic forest, southeastern Brazil. We also investigated reproductive effort and size-fecundity relationships in females. Reproductive traits were compared to other species in the genus Physalaemus, especially those included in the P. signifer group. Physalaemus crombiei is a prolonged breeder, reproducing throughout the year with a peak of activity during the most rainy months (October-March). Males called from the humid forest foor and eggs embedded in foam nests were deposited in the water as well as on the humid foor amidst the leaf litter, or inside fallen leaves or tree holes containing rainwater on the forest foor. As expected, P. crombiei exhibited three alternative reproductive modes, as described for other species of the P. signifer group. The number of eggs produced per female varied from 91 to 250. Female body size is positively correlated both with ovary mass and clutch size (number of eggs per clutch). Variation in the number and size of eggs observed in Physalaemus species may be explained not only by female size, but also by the terrestrial reproductive mode exhibited by the species in the P. signifer group.

Hematological and incubation parameters of chicks from young breeders eggs: Variation with sex and incubation temperature

This experiment analyzed the effect of sex and incubation temperature on daily mass loss and eggshell conductance, embryo mortality rates, incubation duration, hematological parameters and body, liver, heart and bursa weights of neonatal chicks from young breeders. The daily mass loss was higher at incubation temperature of 39°C. The eggshell conductance rate increased with the temperature. The total and partial duration of incubation were lower for eggs incubated at 39°C. The time taken by the chick to leave the eggshell did not differ below and above the thermoneutral temperature. The total and intermediate embryo mortality rates increased with the incubation temperature, whereas the early and late embryo mortality rates were higher at incubation temperature of 39°C. Sex did not influence the analyzed parameters, while the incubation temperature did not affect the body and bursa weight and the erythrocytes characteristics. The liver weight of chicks incubated at 36°C was higher than the incubated at 39°C, however there were no differences among the liver weight from chicks incubated at 36 and 39°C and those incubated at 37.5°C. The number of heterophils and the heterophil/lymphocyte ratio (H/L ratio) increased following the temperature, whereas the number of lymphocytes decreased at high temperatures. The other leukocyte parameters did not suffer influence of temperature. Males and females presented similar response to variation of incubation temperatures (36, 37.5 and 39°C) and demonstrated higher sensibility to temperatures above the thermoneutral. Moreover, temperatures below the thermoneutral demonstrated to be better for improvement of hatchability and development of chicks from light eggs. © Asian Network for Scientific Information, 2010.

The pioneering use of ISSR (Inter Simple Sequence Repeat) in Neotropical anurans: Preliminary assessment of genetic diversity in populations of Physalaemus cuvieri (Amphibia, Leiuperidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Terminal-repeat retrotransposons with GAG domain in plant genomes: a new testimony on the complex world of transposable elements

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Short communication: Variable number of tandem repeat polymorphisms in DGAT1 gene of buffaloes (Bubalus bubalis) is associated with milk constituents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Repeat pregnancies among adolescents in a tertiary hospital in Brazil

Objective: to investigate factors associated with repeat pregnancies among adolescents in a tertiary hospital in the city of Sao Paulo, Brazil. Background: Teenage mothers present a high risk of repeat pregnancies during adolescence. Most of these pregnancies are unplanned. Methods: A cross-sectional study conducted in a tertiary hospital in Sao Paulo, Brazil. The study population included 745 first-time pregnancies and 170 two or more times pregnant teenagers hospitalised for childbirth. Logistic regression models were used to identify independent factors associated with repeat pregnancy in this population. Results: Older age at first pregnancy was associated with a decreased risk of repeat pregnancies (odds ratio and 95% confidence interval 0.78 (0.68-0.89)). Prenatal examinations (0.13 (0.05-0.32)), higher education (0.83 (0.76-0.91)) and higher monthly income (0.79 (0.67-0.95)) were also protective against repeat pregnancies. Those who used contraceptives (2.76 (1.80-4.21)) and lived with their partners (2.44 (1.53-3.88)) had an increased risk of becoming pregnant more than once. Conclusion: Preventive programmes aiming to avoid repeat pregnancies in adolescents should not be restricted to the transmission of information. Behavioural changes in family planning must include access not only to adequate information but also to adequate healthcare, contraceptive methods, education and training.

Cloning and characterisation of a novel chromosome end repeat enriched with homopolymeric (dA)/(dT) DNA in Rhynchosciara americana (Diptera: Sciaridae)

Short tandem DNA repeats and telomerase compose the telomere structure in the vast majority of eukaryotic organisms. However, such a conserved organisation has not been found in dipterans. While telomeric DNA in Drosophila is composed of specific retrotransposons, complex terminal tandem repeats are present in chromosomes of Anopheles and chironomid species. In the sciarid Rhynchosciara americana, short repeats (16 and 22 bp long) tandemly arrayed seem to reach chromosome ends. Moreover, in situ hybridisation data using homopolymeric RNA probes suggested in this species the existence of a third putative chromosome end repeat enriched with (dA).(dT) homopolymers. In this work, chromosome micro-dissection and PCR primed by homopolymeric primers were employed to clone these repeats. Named T-14 and 93 % AT-rich, the repetitive unit is 14 bp long and appears organised in tandem arrays. It is localised in five non-centromeric ends and in four interstitial bands of R. americana chromosomes. To date, T-14 is the shortest repeat that has been characterised in chromosome ends of dipterans. As observed for short tandem repeats identified previously in chromosome ends of R. americana, the T-14 probe hybridised to bridges connecting non-homologous polytene chromosome ends, indicative of close association of T-14 repeats with the very end of the chromosomes. The results of this work suggest that R. americana represents an additional example of organism provided with more than one DNA sequence that is able to reach chromosome termini.

Contribution of graduate programs in plant breeding to the education of plant breeders in Brazil

The success of agribusiness in Brazil in recent decades is unquestionable. Although the country has always had favorable conditions for agriculture (land, water and climate), this success has only come about recently, due to scientific research, which has resulted in considerable increases in yield and in improvement of product quality, as well as making the occupation of new agricultural frontiers possible. A decisive factor for development of agriculture in the country was the creation of EMBRAPA in 1973, which, in a few years, led to considerable demand for researchers with training in graduate programs. Among them are plant breeders, who came to exercise their activity throughout the country and in all ecosystems. The training of plant breeders was only possible because, as from the middle of the 1960s, the country began a wide-ranging education program, with the creation of several graduate programs in genetics and plant breeding.

Occurrence and characterization of rotavirus A in broilers, layers, and broiler breeders from brazilian poultry farms

Rotaviruses are a major cause of diarrhea in humans and animals, including several mammalian and avian species. Using different PCR protocols, we report the occurrence of rotavirus A in 21 (53.84%; 21/39) from 39 fecal pool samples of broilers, layers, and broiler breeders from Brazilian avian farms. We typed the G5, G8, G11, G19, and P[31] genotypes

A novel fusion toxin derived from an EpCAM-specific designed ankyrin repeat protein has potent antitumor activity

Designed ankyrin repeat proteins (DARPins) hold great promise as a new class of binding molecules to overcome the limitations of antibodies for biomedical applications. Here, we assessed the potential of an epithelial cell adhesion molecule (EpCAM)-specific DARPin (Ec4) for tumor targeting as a fusion toxin with Pseudomonas aeruginosa exotoxin A.

"Pseudo-Beijing": evidence for convergent evolution in the direct repeat region of Mycobacterium tuberculosis

Background Mycobacterium tuberculosis has a global population structure consisting of six main phylogenetic lineages associated with specific geographic regions and human populations. One particular M. tuberculosis genotype known as “Beijing” has repeatedly been associated with drug resistance and has been emerging in some parts of the world. “Beijing” strains are traditionally defined based on a characteristic spoligotyping pattern. We used three alternative genotyping techniques to revisit the phylogenetic classification of M. tuberculosis complex (MTBC) strains exhibiting the typical “Beijing” spoligotyping pattern. Methods and Findings MTBC strains were obtained from an ongoing molecular epidemiological study in Switzerland and Nepal. MTBC genotyping was performed based on SNPs, genomic deletions, and 24-loci MIRU-VNTR. We identified three MTBC strains from patients originating from Tibet, Portugal and Nepal which exhibited a spoligotyping patterns identical to the classical Beijing signature. However, based on three alternative molecular markers, these strains were assigned to Lineage 3 (also known as Delhi/CAS) rather than to Lineage 2 (also known as East-Asian lineage). Sequencing of the RD207 in one of these strains showed that the deletion responsible for this “Pseudo-Beijing” spoligotype was about 1,000 base pairs smaller than the usual deletion of RD207 in classical “Beijing” strains, which is consistent with an evolutionarily independent deletion event in the direct repeat (DR) region of MTBC. Conclusions We provide an example of convergent evolution in the DR locus of MTBC, and highlight the limitation of using spoligotypes for strain classification. Our results indicate that a proportion of “Beijing” strains may have been misclassified in the past. Markers that are more phylogenetically robust should be used when exploring strain-specific differences in experimental or clinical phenotypes.

Interventions to increase rescreening for repeat chlamydial infection

Repeat infection with Chlamydia trachomatis following treatment is common and increases the risk of sequelae. Despite clinical guidelines recommending rescreening within 3 months of treatment, rescreening rates remain low. We undertook a systematic review to identify studies that compared rates of rescreening for repeat chlamydial infection between patients receiving and not receiving an intervention.