Le(a-b-) phenotype: potential risk factor for infection by the RH strain of Toxoplasma gondii in pregnancy

The Lewis histo-blood group system is characterized by the expression of the Lea and Le(b) antigens in the gastrointestinal tract, whose synthesis results in interactions between alpha 2-L-fucosyltransferase (FUTII) and alpha 3/4-L-fucosyltransferase (FUTIII) enzymes coded by the FUT2 (19q. 13.3) and FUT3 (19p13.3) genes. FUTII and FUTIII fucosylate the type 1 oligosaccharide precursor (Gal beta 1 -> 3NAcGlc beta 1 -> 3-R) at distinct positions to form H type 1 (Fuc alpha 1. 2Gal beta 1. 3NAcGlc beta 1 -> 3-R) and Le(a) (Gal beta 1 -> 3[Fuc alpha 1 -> 4] NAcGlc beta 1 -> 3-R) antigens, respectively. The fucosylation of H type 1 antigens by FUTIII results in the Leb antigen (Fuc alpha 1. 2Gal beta 1. 3[Fuca1. 4] NAcGlc beta 1. 3-R). Thus, the presence of the FUTII and FUTIII enzymes leads to the expression of the Le(a+b+) phenotype, while the presence of only FUTIII allows the expression of the Le(a+b-) phenotype. The absence of the FUTIII enzyme leads to the expression of the Le(a-b-) phenotype, independent of the presence or absence of FUTII. Point mutations in FUT2 and FUT3 genes change the activity of these enzymes, impair the synthesis of Le(a) and Le(b) antigens, and contribute to the variability of Lewis phenotypes in the gastrointestinal tract. Toxoplasma gondii, an apicomplexan parasite that infects a large proportion of the world's population, utilizes the gastrointestinal tract as an infection route and seems to adhere to glycosylated molecules to invade human cells. These apparently independent events may be related. The aim of this study was to test the hypothesis that there is an association between the Lewis histo-blood group system and infection by T. gondii. Two hundred and nine serum samples collected from pregnant women were submitted to screening tests to detect anti-T. gondii antibodies, employing the indirect hemagglutination method. ELISA was utilized to identify IgG class anti-T. gondii antibodies specific for the RH strain. A hundred and ninety-five samples with concordant results for both methods were selected to form two groups: seropositive (G1) and seronegative (G2). The G428A mutation of the FUT2 gene, and T202C and C314T of the FUT3 gene, which allow inference of the gastrointestinal tract Lewis phenotypes, were identified using PCR-RFLP and PCR-SSP methods, respectively. Among the 195 samples selected, 116 (59.5%) were seropositive and 79 (40.5%) were seronegative. In G1, 68 (58.6%) were classified as Le(a+b+), 30 (25.9%) as Le(a+b-), and 18 (15.5%) as Le(a-b-), and in G2, 67 (84.8%) were classified as Le(a+b+), 12 (15.2%) as Le(a+b-), and 0 (0%) as Le(a-b-) (P < 0.0001). The Le(a-b-) phenotype is associated with a high risk of RH strain T. gondii infection when compared with the Le(a+b+) [P = 0.0001; OR = 36,460; 95%CI = 2.152-617,680] and Le(a+b-) phenotypes [P = 0.0118; OR = 15,165; 95%CI = 0.8463-271,710]. The Le(a+b-) phenotype showed a higher risk compared to the Le(a+b+) phenotype [P = 0.0206; OR = 2463; 95%CI = 2463-5214]. The results suggest that the Le(a-b-) phenotype is strongly associated with a greater risk of infection by the RH strain of T. gondii compared to the other phenotypes. It is possible that the absence of fucosylation of the type 1 oligosaccharide precursor as well as the variations in the structures of the Le(a) and Le(b) antigens influence susceptibility to infection by this parasite.

The physiology and impact on fertility of the period of proestrus in lactating dairy cows

In cattle, proestrus begins with the initiation of luteolysis and ends with initiation of estrus and the GnRH/LH surge. This period is marked by a dramatic decrease in circulating progesterone (P4) that reaches a nadir by about 36-48 h in cows undergoing natural or prostaglandin F2 alpha (PGF)-induced luteolysis. Inadequate luteolysis is a cause of reduced fertility particularly in timed AI programs with small elevations in circulating P4 reducing fertility. Increasing circulating estradiol (E2) during proestrus is dependent on presence, size, and function of the dominant follicle and this varies during natural proestrus, due to whether animals have two or three follicular waves, and during PGF-induced proestrus, according to stage of the follicular wave at time of PGF treatment. Inadequate circulating E2 can limit fertility and increase pregnancy loss in some specific circumstances such as in cows with low BCS and in cows during heat stress. Thus, studies to optimize the length of proestrus and the concentrations of E2 and P4 during proestrus could produce substantial improvements in fertility and reductions in pregnancy loss.

Developmental aspects of early pregnancy in mares

In mares, the embryo migrates to the uterus between days 5 and 6 postovulation beginning its mobility through all uterine segments, which is essential for the maternal recognition of pregnancy. During the mobility phase, the embryonic vesicle shows a linear growth rate until its fixation between days 15 and 17, when the orientation phenomenon occurs. From fixation to day 28 of pregnancy, the embryonic growth is less evident (plateau) by cross-section ultrasound examination. After this period the linear growth rate is reestablished until day 46. This plateau is attributed to the increased uterine tone that compresses the vesicle and to volume expansion, making it difficult to detect the conceptus growth only by the cross-section diameter. Around day 20, the embryo proper is visualized as an echogenic spot in the ventral aspect of the vesicle. Additionally, development of allantoic sac, embryonic heartbeat, yolk sac regression and posterior umbilical cord formation also can be visualized from days 20 to 40. An intimate interaction between uterus and conceptus is essential for the normal pregnancy development. Color-and spectral-Doppler ultrasonography can be useful for the evaluation of this interface. A gradual increase on uterine vascularity during the early pregnancy and transient changes in endometrial vascularity accompanying the vesicle location during the mobility phase have been described. Around day 38 of gestation, the formation of the endometrial cups begins and, consequently, the synthesis of the equine chorionic gonadotropin (eCG) induces the formation and development of supplementary corpora lutea, which are important to secrete progesterone and to maintain pregnancy until around day 120.

Doppler ultrasound in pregnancy assessment in bitches - literature review

Doppler ultrasound enables the assessment of blood flow in real time and has been widely used to aid in pregnancy diagnosis and monitoring in dogs and cats. This technique has a diferencial when compared with the B-mode ultrasound, as it allows the evaluation of vascular hemodynamic characteristics, while the two-dimensional ultrasound allows the diagnosis of pregnancy and fetal viability. Thus, the objective of this review is to describe how circulation is characterized in the uterine and fetal arteries in bitches during pregnancy using Doppler ultrasonography.

Comparative study of ultrasonographic methods for assessment of pregnancy age in bitches

Compared with human beings, the application of ultrasound in estimating fetal age in bitches is limited due to the large variation of breed and size in this species. Several formulas were developed to calculate the gestational age and to provide the date of birth in dogs, but the efficacy of these formulas on the different gestational stages and dog breeds is unknown. The aim of this study was to compare sonographic methods for assessment of gestational age and days before parturition in dogs with different body weights and pregnancy stages. Twenty seven bitches of several sizes were examined and divided into three groups according to the initial body weight (A: <10kg; B: 10.1 - 20kg; C: >20.1kg); then each group was divided into three subgroups according to pregnancy stage (1st: 18 to 30 days; 2nd: 31 to 40 days; 3rd: >40 days) estimated according to the first day of copulation. Ultrasonography was performed weekly from the first stage of pregnancy. In the first and second stage the following formulas were applied: GA = (6XGSD) + 20; DBP = 65 - IG; by Nyland & Matton (2002); GA: gestational age; DBP: days before parturition; DSG: gestational sac diameter; in the third stage: DBP = 61,2 - (24,6 X BD); DBP = 43,5 - (10,9 X CD); by Burk & Ackerman (1996); BD: biparietal diameter; CD: body diameter, and: GA = (15 X BD) + 20; GA = (7 X CD) + 29; GA = (6 X BD) + (3 X CD) + 30; DBP = 65 - GA; by Nyland & Matton (2002). Results were compared statistically. The equations proposed by Nyland & Matton (2002), were more accurate in all pregnancy stages, with a margin of error of only three days, regardless of the size of the animal; therefore these methods are the best option in veterinary practice.

Cord blood cytokine levels in focal early-onset neonatal infection after preterm premature rupture of membranes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Polimorfismo do gene IL6 candidato à predisposição à rotura prematura de membranas pré-termo e ao trabalho de parto pré-termo

Introduction: Preterm Labor (PTL) and Preterm Premature Rupture of Membranes (PPROM) cause severe complications for both mother and fetus. Among the risk factors associated with preterm labor and PPROM, genetic predisposition has been gaining importance. However, the association between polymorphic genes and the pathogenesis of PTL and PPROM remains elusive. A better understanding of the genetic mechanisms underlying these adverse pregnancy outcomes may enable the identification of high risk patients and allow new approaches to minimize the deleterious effects of prematurity. Aim: To determine the association between maternal IL-6 polymorphism gene and the occurrence of PTL and PPROM. Patients and Methods: The study included 109 patients with prior history of PL and/or PPROM that delivered prematurely at the Obstetrical Unit Care of Botucatu Medical School, UNESP between 2003 and 2012. The control group consisted of 68 patients that delivered at term, matched to the case group by age, ethnicity, and sex of the newborn. Oral swabs (Cath-AllTM – Epicentre Biotechnologies) were collected for analysis of genetic polymorphisms by PCR. Statistical tests were performed to compare genotype, clinical and socio-demographic data from the groups. A p-value of <0.05 was considered significant. Results: The sociodemographic characteristics in both groups were homogeneously distributed. The frequency of the polymorphic allele C, associated with less production of IL-6, and therefore thought to be protective against PTL and PPROM, was 32,5% in the study group and 30,9% in the control group, without statistically significant differences. Conclusion: Considering the sample size included in this study, the frequency of the mutated allele is similar in pregnant women who delivered at term and gestational complications as PTL and PPROM

Utilização de gonadotropina coriônica equina em protocolos de inseminação artificial em tempo fixo em bovinos de corte

Current cattlemen must seek methods to maximum reproductive efficiency of their beef herds, making the business competitive and enhancing greater profitability. For the cow-calf producers, efficiency translates into more cows producing one calf every year. Fixed-time artificial insemination (TAI) is one of several technologies that producers utilize to reach this goal. Postpartum anestrus is one of the biggest obstacles to overcome in order to obtain suitable results at the end of the breeding season. The TAI protocols are efficient in re-establishing cyclicity in noncycling cows during the postpartum period, streamlining the use of labor on farms, allowing the use of artificial insemination (AI) on a large scale, and introducing superior genetics to the herd. The protocols that are most commonly used in Brazil are based on progesterone (P4) releasing devices that prevent premature estrus and ovulation; and estradiol (E2) to synchronize the initiation of a new follicular wave. In such protocols, administration of equine chorionic gonadotropin (eCG) helps the development of the follicle, increases ovulation rate, improves the endocrine and uterine environment during proestrus and diestrus, and improves fertility. The use of eCG in TAI protocols for suckled cows, non-lactating cows and heifers increases the pregnancy rate allowing more calves at the end of the breeding season and higher profitability to the cattlemen

Ultrasonography of the conceptus development from days 15 to 60 of pregnancy in non-cyclic recipient mares

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

Intrauterine growth restricted rats exercised at pregnancy: maternal-fetal repercussions

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Microorganisms in the female genital tract during pregnancy: tolerance versus pathogenesis

Microorganisms in the pregnant female genital tract are not always associated with pathology. The factors that influence the maternal response to microorganisms remain ill defined. We review the state of knowledge of microbe-host interactions in gestational tissues and highlight mechanisms that promote tolerance or pathogenesis. Tolerance to microorganisms is promoted during pregnancy by several mechanisms including upregulation of anti-inflammatory mediators, induction of endotoxin tolerance, and possibly by regulation of autophagy. Conversely, an altered vaginal microbiota or a pre-existing viral presence may result in induction of excessive inflammation and preterm labor. Although infections play a prevalent role in preterm birth, microbes are present in gestational tissues of women with healthy outcomes and may provide beneficial functions. The complex interactions between different microbial species and the maternal immune system during gestation remain incompletely elucidated.

Re-used progesterone devices efficiently synchronise oestrus and ovulation after autoclaving process in Toggenburg goats during the breeding season

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)