The role of proestrus on fertility and postovulatory uterine function in the cow

Modern protocols to synchronize ovulations for timed artificial insemination and timed embryo transfer that include manipulations in the proestrus period (i.e., between luteolysis and estrus) affect fertility in cattle. Specifically, stimulating pre-ovulatory follicle growth and exposure to estrogens after CL regression increase the proportion of cows pregnant and decrease late embryo mortality. Such effects may be due to both preovulatory actions of estrogens and post-ovulatory actions of progesterone, as concentrations of the later hormone may be changed in response to manipulations conducted during proestrus. In the first portion of this paper we describe strategies used recently to manipulate the proestrus period in protocols for synchronization of ovulation, and to present evidence of their effects on fertility. Manipulations of timing and prominence of sex steroids during the proestrus and early diestrus that affect fertility may act on targets such as the endometrium. This tissue expresses receptors for both estrogens and progesterone and these hormones change endometrial function to support conceptus growth and pregnancy maintenance. However, specific cellular and molecular mechanisms through which fertility is affected via manipulations of the proestrus are poorly understood. In the second portion of this paper we describe a well-defined animal model to study changes in endometrial function induced by manipulations conducted during the proestrus. Such manipulations induced endometrial changes on sex steroid receptors expression, cell proliferation, oxidative metabolism and eicosanoid synthesis in the uterus, but not on glucose transport to uterine lumen. In summary, evidence is accumulating to support a positive role of increasing duration and estrogen availability during the proestrus on fertility to synchronization protocols. Such positive effects may be through changes in endometrial function to stimulate conceptus growth and survival.

Assessment of structural cardiac abnormalities and diastolic function in women with gestational diabetes mellitus

Background: The main manifestation of hyperglycaemia during pregnancy is gestational diabetes mellitus. It can herald diabetes mellitus type 2 and its deleterious long-term effects, such as hypertension and cardiovascular disease. The aim of this study was to assess diastolic function in women with gestational diabetes mellitus, one of the first signs of future cardiovascular disease.Methods: A total of 21 women with gestational diabetes mellitus and 23 healthy pregnant women (control group) between 34 and 37weeks of gestation underwent echocardiographic assessment. The diagnosis of gestational diabetes mellitus was made in agreement with the American Diabetes Association criteria. Echocardiographic images obtained were analysed according to the criteria of the American Society of Echocardiography. Data were analysed using Pearson correlation coefficient, analysis of variance and Student's t-test.Results: Women with gestational diabetes mellitus had higher posterior wall and interventricular septum thickness, increased left ventricular mass and left ventricular mass index, lower early diastolic annular velocity and early diastolic annular velocity/late diastolic annular velocity ratio. There was a positive correlation between left ventricular mass index and fasting glucose and pregnancy body mass index.Conclusion: Patients with gestational diabetes mellitus seem to have a different diastolic profile as well as a mildly dysfunctional pattern on echocardiogram, which may show a need for greater glycaemic control.

Expression of genes related to mitochondrial function in Nellore cattle divergently ranked on residual feed intake

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

Managing soil carbon for multiple ecosystem benefits positive exemplars: Latin America (Brazil and Argentina)

Agriculture provides food, fibre and energy, which have been the foundation for the development of all societies. Soil carbon plays an important role in providing essential ecosystem services. Historically, these have been viewed in terms of plant nutrient availability only, with agricultural management being driven to obtain maximum benefits of this soil function. However, recently, agricultural systems have been envisioned to provide a more complete set of ecosystem services, in a win-win situation, in addition to the products normally associated with agriculture. The expansion and growth of agricultural production in Brazil and Argentina brought about a significant loss of soil carbon stocks, and consequently the associated ecosystem services, such as flooding and erosion control, water filtration and storage. There are several examples of soil carbon management for multiple benefits in Brazil and Argentina, with new soil management techniques attempting to reverse this trend by increasing soil carbon (C) stocks. One example is zero tillage, which has the advantage of reducing CO2 emissions from the soil and thus preserving or augmenting C stocks. Crop rotations that include cover crops have been shown to sequester significant amounts of C, both in Brazilian subtropical regions as well as in the Argentinean Pampas. Associated benefits of zero tillage and cover crop rotations include flood and erosion control and improved water filtration and storage. Another positive example is the adoption of no-burning harvest in the vast sugarcane area in Brazil, which also contributes to reduced CO2 emissions, leaving crop residues on the soil surface and thus helping the conservation of essential plant nutrients and improving water storage.

Safety of kidney transplantation using anti-HBc-positive donors

Background. Prospective studies evaluating the risk of hepatitis B virus (HBV) transmission in transplants of kidneys from hepatitis B core antibody (anti-HBc)-positive/ hepatitis B surface antibody (anti-HBs) negative donors are still lacking. The objective of this study was to assess the safety of kidney transplantation with the use of anti-HBc positive donors.Methods. This prospective case series study included 50 kidney transplant recipients from anti-HBc positive donors with or without anti-HBs positivity. Recipients were required to test positive for anti-HBs (titers >10 mUI/mL), regardless of anti-HBc status, and negative for hepatitis B surface antigen (HBsAg). Recipient and donor data were retrieved from medical records, databases, and organ procurement organization sheets. Liver function tests were performed at progressively increasing post-transplantation intervals. Complete serologic tests for HBV were performed before transplantation, 3 and 6 months after transplantation, and annually thereafter.Results. Six months after transplantation, all recipients were negative for HBsAg, HBeAg, anti-HBe, and anti-HBcIgM. No seroconversion was observed among the 20 patients who received kidneys from anti-HBc positive/anti-HBs negative donors. No patient showed elevated liver enzymes during follow-up.Conclusions. Kidney transplantation using organs from anti-HBeIgG positive donors (even when they are concurrently anti-HBs negative) in anti-HBs positive recipients is a safe procedure and may be considered as a way to expand the donor pool.