Genetic profile of Brazilian patients with dystrophinopathies.

Different types of mutations in the DMD gene underlie Duchenne muscular dystrophies (DMD) and Becker muscular dystrophies (BMD). Large deletions and duplications are the most frequent causative genetic alterations worldwide, but little is known about DMD/BMD genetic profile in Brazil. Hence, we recruited patients with DMD and BMD from 8 neuromuscular reference centers along the country, and performed a comprehensive molecular investigation that included Multiplex Ligation-dependent Probe Amplification and Next generation sequencing (NGS) analyses. We evaluated 199 patients from 177 unrelated families: 166 with DMD, 32 with BMD and 1 1.5 years old asymptomatic patient with persistent hiperCKemia. Overall, large deletions (58.2%) followed by nonsense mutations (12.4%) and large duplications (11.3%) were the most frequent variants in Brazilian families. Large deletions were less frequent in BMD than in DMD (44.8% vs 60.8%). We identified 19 new DMD variants. Nonsense mutations were significantly more frequent in patients from northeastern region than from southern/southeastern regions of Brazil (27.7% vs 8.5%, P < .05). Genetic profile of Brazilian patients with DMD/BMD is similar to previously reported cohorts, but it is not uniform across the country. This information is important to plan rational clinical care for patients in face of the new coming mutation-specific therapies.

Thermoelectric transport properties of armchair graphene nanoribbon heterostructures.

In this paper, we numerically analyze the thermoelectric (TE) properties of recently synthesized graphene nanoribbon (GNR) heterostructures that are obtained as extensions of pristine armchair graphene nanoribbons (AGNRs). After simulating their band structure through a nearest-neighbor tight-binding model, we use the Landauer formalism to calculate the necessary TE coefficients, with which we obtain the electrical conductanceG, thermopowerS, thermal conductanceKe, linear-response thermocurrentIth/ΔT=GS, and figure of meritZT(using literature results for the phonon thermal conductanceKph), at room temperature. We then compare the results for the nanoribbon heterostructures with those for the pristine AGNR nanoribbons. The comparison shows that the metallic AGNRs become semiconducting (with much higherZTvalues) after the inclusion of the extensions that transform them into heterostructures and that some heterostructures have higher values ofZTwhen compared to the semiconducting pristine AGNRs from which they have originated.

The role of sperm aneuploidy as a predictor of the success of intracytoplasmic sperm injection?

BACKGROUND: We present the first powered prospective study to assess whether sperm aneuploidy can predict the outcome of ICSI. METHODS: Our null hypothesis was that aneuploidy rates (AR) are identical in men who achieve successful (Group A) and unsuccessful (Group B) ICSI outcome. A power calculation yielded a sample number of 56 to achieve 80% power to reject our hypothesis at the 5% significance level. Samples for testing were obtained on the day of embryo transfer and tests were performed on raw pre-preparation samples. Sperm AR of chromosomes 13, 18, 21, X/Y were assessed using fluorescence in-situ hybridization (FISH) techniques (mean of 1223 sperm). RESULTS: There was no significant difference in any patient, seminal, cycle or laboratory characteristic between groups that may have affected outcome. Total AR (2.37 versus 1.18%, P = 0.01), as well as AR of chromosomes 18, X/Y and 18 + X/Y (1.48 versus 0.67%, P = 0.005) were significantly higher in Group B compared with Group A. Regression analysis confirmed these differences to be independent of other variables and showed a 2.6-fold change in odds of achieving a pregnancy for every 1% change in total AR. CONCLUSIONS: Our findings confirm a potential role for aneuploidy testing in the work-up of ICSI patients as a predictor of success, as well as in future genetic counselling. If confirmed, there may also be a place for a study of preimplantation genetic screening to improve ICSI success in men found to have high AR and ICSI failure.

The relationship between chromosomal abnormality in the human preimplantation embryo and development in vitro.

The relationship between the survival of the human preimplantation embryo in vitro and chromosomal abnormality was investigated by cytogenetic analysis of a total of 250 embryos of varying morphology between the pronucleate stage and the 8-cell stage. The overall incidence of chromosomal abnormality among these embryos was 49%. At the pronucleate stage (n = 46) the incidence was 65.2%, at the 2-4-cell stage (n = 126) it was 54.6%, and at the 5-8-cell stage (n = 78) it was 27.4%. Cleavage-stage embryos with poor morphology (irregular shaped blastomeres with severe extracellular fragmentation) showed a higher incidence of chromosomal abnormality (62%; 54 of 87 analysed) than those with good morphology (22.2%; 26 of 117 analysed). This study demonstrates: (i) that there is progressive loss of chromosomally-abnormal embryos during preimplantation development; and (ii) that there is an association between chromosomal abnormality and embryo morphology.

Cytogenetic analysis of human preimplantation embryos following developmental arrest in vitro.

The relationship between chromosomal abnormalities in the human preimplantation embryo and developmental arrest in vitro was investigated. Cytogenetic analysis of 171 embryos that had arrested between the pronucleate and the 8-cell stages demonstrated that the overall incidence of chromosomal abnormality among these embryos was 63.4%. Of the embryos that arrested at the pronucleate stage (n = 48), 47.9% were chromosomally abnormal, compared with 59.5% of those that arrested between the 2- and 4-cell stages (n = 50), and 82.8% of those arrested between the 5- and 8-cell stage (n = 73). The rate of abnormality in embryos with poor morphology (irregular shaped blastomeres and considerable extracellular fragmentation) was significantly higher (86.8%; n = 33) than those with good morphology (60%; n = 51; P<0.005). These results suggest that there is an association between chromosomal abnormality, developmental arrest in vitro, and poor morphology.

[Maternal mortality in Brazil, 1980]. / Mortalidade materna no Brasil, 1980.

PIP: The authors studied Brazilian maternal mortality by examining official statistics from the country's various geographical regions, including the state of Sao Paulo, Brazil. 1980 was selected because of the possibility of working with data from the Population Census of that year. The principal causes of death in Brazil were hypertension, hemorrhage, puerperal infection, and abortion. In Sao Paulo, where the 4th digit of the IDC is used, the main cause of death was eclampsia. The 2nd was hemorrhage, and the 3rd was infection, whether due to or associated with pregnancy. As for age, the lowest maternal mortality rate occurred in the 20-29 year old age group, the rate was slightly higher for those ages 15-19, and increasing gradually in those ages 30-39 and 40-49. It was not possible to analyze the rates for those ages 10-14 and over age 50 because of lack of data on livebirths. However, there were 18 deaths and 4 deaths respectively in those groups which shows that at opposite poles of the reproductive span, there exists a considerably high mortality rate. In comparing these data with those of other countries, it was found that the majority of deaths are avoidable and that it should be possible to reduce the number considerably by means of better health care for women and by using techniques and resources which are already available. (author's modified)^ieng

[Maternal mortality due to heart disease]. / Mortalidade materna por cardiopatia.

A retrospective study on maternal mortality in pregnant women with cardiac disease over a period of eleven years (January 1979 to December 1989) was undertaken. The objective was an analysis of the main aspects of this association. Cardiac disease was diagnosed in 694 patients (4.2%) of a total of 16,423 admitted to the Obstetrics Department of the Escola Paulista de Medicina. As for etiology, rheumatic disease (52.3%); Chagas's disease (19.3%) and congenital disease (8.1%) were the most frequent causes. There were 51 maternal deaths, according to FIGO's definition (1967), corresponding to a maternal mortality rate of 428.2/100,000 livebirths during the same period. Twelve of these maternal deaths were due to cardiac disease (maternal mortality rate of 100.8/100,000 livebirths). The statistical analysis identified the following aspects associated with maternal mortality among patients with cardiac disease: primigravida, lack of adequate prenatal care, and cardiac surgery performed previously to and/or during pregnancy. Congestive heart failure with pulmonary edema (41.7%) and thromboembolism (25.0%) were the most frequent causes of maternal death among patients with cardiac disease. The NYHA functional classification was not a good parameter for pregnancy prognosis: eleven patients (91.7%) were considered as belonging to the favorable group before they became pregnant. Most maternal deaths occurred during the first 72 hours after delivery. Therefore, this period was considered most critical for maternal mortality in patients with cardiac disease. No relation-ship was found among the factors: maternal age, race, marital status, delivery and maternal mortality among patients with cardiac disease.(ABSTRACT TRUNCATED AT 250 WORDS)

[Heart surgery with extracorporeal circulation in pregnant women. Analysis of materno-fetal outcome]. / Cirurgia cardíaca com circulação extracorpórea em gestantes. Análise da evolução materno-fetal.

PURPOSE: To analyze maternal and fetal outcome in pregnant undergone to cardiac surgery. METHODS: We studied the evolution of 30 pregnant women submitted to cardiac surgery at the Hospital São Paulo, between Jan/81 and Dec/92 and, further, attended at this Hospital till the parturition. The following variables were analyzed: cardiopulmonary bypass, time of the procedure and time of the anoxia, patient temperature, surgical complications, and neonatal, maternal and fetal outcomes. RESULTS: All patients had rheumatic heart disease and, in 17, mitral stenosis was the main anatomic abnormality. Mitral commissurotomy was performed in 24 patients, double comissurotomy (mitral and aortic) in 1 patient and valve replacement was performed in 5. Cardiopulmonary bypass was utilized in all procedure; occurrence of surgical complications (p < 0.001) and the prolonged surgical time (p = 0.009) were related to the fetal mortality. There was 4 (13.3%) maternal deaths and 10 (33.3%) fetal deaths related to the surgery. CONCLUSION: The indication of cardiac surgery in pregnant women is heart failure, refractory to conventional therapy; cardiopulmonary bypass is associated with high fetal mortality.