Trypanosoma cruzi Presenilin-Like Transmembrane Aspartyl Protease: Characterization and Cellular Localization.

The increasing detection of infections of Trypanosoma cruzi, the etiological agent of Chagas disease, in non-endemic regions beyond Latin America has risen to be a major public health issue. With an impact in the millions of people, current treatments rely on antiquated drugs that produce severe side effects and are considered nearly ineffective for the chronic phase. The minimal progress in the development of new drugs highlights the need for advances in basic research on crucial biochemical pathways in T. cruzi to identify new targets. Here, we report on the T. cruzi presenilin-like transmembrane aspartyl enzyme, a protease of the aspartic class in a unique phylogenetic subgroup with T. vivax separate from protozoans. Computational analyses suggest it contains nine transmembrane domains and an active site with the characteristic PALP motif of the A22 family. Multiple linear B-cell epitopes were identified by SPOT-synthesis analysis with Chagasic patient sera. Two were chosen to generate rabbit antisera, whose signal was primarily localized to the flagellar pocket, intracellular vesicles, and endoplasmic reticulum in parasites by whole-cell immunofluorescence. The results suggest that the parasitic presenilin-like enzyme could have a role in the secretory pathway and serve as a target for the generation of new therapeutics specific to the T. cruzi.

Genetic and nongenetic profiling of milk pregnancy-associated glycoproteins in Holstein cattle.

Pregnancy-associated glycoproteins (PAG) are secreted by the trophoblast and are detectable in maternal circulation around the time of attachment of the fetal placenta, as well as in blood and milk throughout gestation. The understanding of the genetic mechanisms controlling PAG levels can confer advantages for livestock breeding programs given the precocity and the ease of obtaining this phenotype from routine pregnancy diagnosis. The aim of this study was to characterize PAG levels by estimating genetic parameters and correlations with other dairy traits, and to identify genomic regions and candidate genes associated with PAG levels in milk. The PAG data consisted of pregnancy diagnoses using commercial assays from 2012 to 2017, and genotype data consisted of 54,123 SNP markers for 2,352 individuals (embryos and dams). The model included contemporary group (herd, year, and season) and embryo age as fixed effects, and random embryonic (direct) and maternal (indirect) genetic effects. Using genomic data, the estimated heritability for direct and maternal genetic effects (± standard deviations) were 0.23 ± 0.05 and 0.11 ± 0.05, respectively. The genetic correlation between these effects was almost zero (0.001 ± 0.06). A preliminary analysis revealed low correlations between milk PAG levels and other dairy traits. The genome-wide association analysis was performed using 2 approaches: single-marker and single-step using all markers. Four genomic regions with direct genetic effects were detected on Bos taurus autosome (BTA) 6, BTA7, BTA19, and BTA29 of the embryonic genome. The BTA29 locus was within the bovine PAG gene cluster, suggesting a cis-regulatory quantitative trait locus on the PAG expression. However, other associations, without an obvious link to PAG expression, could be related to the transportation of PAG and their concentration in milk. Only 1 region from the maternal genome, on BTA4, had a significant indirect effect, where WNT2 is a candidate gene related to placenta vascularization and gestation health. Collectively, our results suggest a moderate genetic control of milk PAG levels from both maternal and fetal genomes, but larger studies are needed to fully evaluate the usefulness of milk PAG in the genetic evaluation of fetal growth and cow fertility.

An integrated computational analysis of the structure, dynamics, and ligand binding interactions of the human galectin network.

Galectins, a family of evolutionarily conserved animal lectins, have been shown to modulate signaling processes leading to inflammation, apoptosis, immunoregulation, and angiogenesis through their ability to interact with poly-N-acetyllactosamine-enriched glycoconjugates. To date 16 human galectin carbohydrate recognition domains have been established by sequence analysis and found to be expressed in several tissues. Given the divergent functions of these lectins, it is of vital importance to understand common and differential features in order to search for specific inhibitors of individual members of the human galectin family. In this work we performed an integrated computational analysis of all individual members of the human galectin family. In the first place, we have built homology-based models for galectin-4 and -12 N-terminus, placental protein 13 (PP13) and PP13-like protein for which no experimental structural information is available. We have then performed classical molecular dynamics simulations of the whole 15 members family in free and ligand-bound states to analyze protein and protein-ligand interaction dynamics. Our results show that all galectins adopt the same fold, and the carbohydrate recognition domains are very similar with structural differences located in specific loops. These differences are reflected in the dynamics characteristics, where mobility differences translate into entropy values which significantly influence their ligand affinity. Thus, ligand selectivity appears to be modulated by subtle differences in the monosaccharide binding sites. Taken together, our results may contribute to the understanding, at a molecular level, of the structural and dynamical determinants that distinguish individual human galectins.

Hormonal evaluation and midcycle detection of intrauterine glycodelin in women treated with levonorgestrel as in emergency contraception.

BACKGROUND: The study was conducted to assess the effects of levonorgestrel (LNG) on hormonal behavior and on the secretory pattern of intrauterine glycodelin at the midcycle of ovulatory women. STUDY DESIGN: Thirty healthy sterilized women with normal ovarian function were studied during one control untreated cycle and one LNG-treated cycle. In the treated cycle, each woman received two doses of 0.75 mg of LNG 12 h apart during the preovulatory phase approximately 2 days before the LH surge. Daily follicle development recordings were performed until follicle rupture was observed, and serum glycodelin, LH, estradiol, estrone and progesterone were measured as well. In addition, glycodelin concentrations were assayed in uterine flushing obtained on Days LH+1 and LH+12. RESULTS: LNG did not modify follicle rupture in 20 of 30 women. In spite of ovulatory progesterone and the occurrence of follicle rupture in these women, luteal phase length was significantly decreased, as well as the serum concentrations of LH, estradiol and estrone in the periovulatory phase. Glycodelin in serum and uterine flushings was significantly elevated in the periovulatory phase when compared to control cycles. CONCLUSIONS: LNG taken at the dose used in emergency contraception before the LH surge increased prematurely serum and intrauterine concentrations of glycodelin at the time of ovulation. Since there are well established glycodelin inhibitory effects upon fertilization, these results may represent an additional action of LNG in situations where the intervention did not interfere with ovulation.

Assessment of plasma profile of pregnancy-associated glycoprotein (PAG) in sheep with a heterologous (anti-caPAG55+59) RIA and its potential for diagnosing pregnancy.

The purpose of the present investigation was to generate pregnancy associated glycoprotein (PAG)-profiles throughout pregnancy in a heterogenous sample of sheep using a radioimmunoassay with a heterologous antibody (anti-caPAG(55+59), #708) and utilize them for the purpose of pregnancy detection. From 2 weeks after the introduction of males into the breeding herd until 4 weeks after parturition, weekly blood samples were collected from 66 pregnant and 25 non-pregnant ewes of various breeds. Between 3 and 5 weeks after conception, plasma PAG levels increased, remained almost stable until week 17, then continued to increase, culminating in a drastic surge during the last 2 weeks of pregnancy. By 4 weeks of gestation, the plasma PAG level exceeded the level typical for non-pregnant ewes by five standard deviations, permitting a reliable pregnancy diagnosis. Plasma PAG levels were higher in twin-bearing ewes than in ewes carrying a single lamb, differences getting more evident as pregnancy proceeded. Neither breed and parity of the mother nor sex and weight of lambs borne exerted a significant effect. The heterologous assay system utilizing a caprine antibody proved to deliver results that are more consistent and less depending on various variables than those used in other studies. It may be concluded that, at the present state of development, the assay provides a reliable means of diagnosing pregnancy in sheep from the 4th week after they have been bred onward.

Ferritina na gravidez em gestantes com hemoglobina normal / Ferritin in pregnant women with normal hemoglobin

We studied in 49 normal pregnant women without anemia the serum levels of Hemoglobin and Ferritin, and subjected to statistical analysis. We showed that the levels of Ferritin were significantly different between the second and the seventh month, and also between the fourth and the seventh, falling in the range of iron-deficient erythropoieses (below 12 ng/ml), perhaps because of low booking Ferritin in women of low social classes. We propose Ferritin, instead of Hemoglobin, as an indicator to iron supplementation in pregnancy.

Aplicabilidad del índice energía/proteína en la evaluación nutricional de la embarazada / Applicability of protein/energy index in the nutritional evaluation of pregnant women

Se evaluó la influencia de la raza, el estado civil y el número de embarazos de un grupo de gestantes sobre el índice energía/proteína. Tanto la raza como el estado civil y el número de embarazos modifican los valores del índice energía/proteína. A las mujeres europoides correspondieron las cifras más elevadas; las mujeres casadas tienen valores más altos que las restantes y, por último, los valores promedios de ese índice aumentan con el número de gestaciones, por lo que al utilizarlo en embarazadas, estos factores deben ser considerados, para evitar los errores que pudiera causar su desestimación

Aplicabilidad del índice energía/proteína en la evaluación nutricional de la embarazada / Applicability of protein/energy index in the nutritional evaluation of pregnant women

Se evaluó la influencia de la raza, el estado civil y el número de embarazos de un grupo de gestantes sobre el índice energía/proteína. Tanto la raza como el estado civil y el número de embarazos modifican los valores del índice energía/proteína. A las mujeres europoides correspondieron las cifras más elevadas; las mujeres casadas tienen valores más altos que las restantes y, por último, los valores promedios de ese índice aumentan con el número de gestaciones, por lo que al utilizarlo en embarazadas, estos factores deben ser considerados, para evitar los errores que pudiera causar su desestimación

Serum pregnancy-associated alpha 2-glycoprotein levels in the evolution of hepatitis B virus infection.

Serum pregnancy-associated alpha 2-glycoprotein (alpha 2-PAG) levels were evaluated in a follow-up study of patients with hepatitis B virus (HBV) infection and compared with biochemical and virological parameters. In a study of 25 patients with acute hepatitis, an association was found between high alpha 2-PAG values, ALT levels, and HBsAg in 20 patients (80%) (P less than 0.05), 18 recovered completely, and 2 had a protracted course. In five patients serum alpha 2-PAG levels were similar to those in the control group. On the other hand, eight (100%) chronic persistent HBV patients showed high levels of alpha 2-PAG (P less than 0.05) during the study period, and these levels correlated well with inflammatory activity and failure of HBsAg elimination. There were no significant differences in alpha 2-PAG values between asymptomatic HBsAg carriers and controls. Serial analysis of alpha 2-PAG, in correlation with viral markers, biochemical parameters, and histological data, would contribute to the ability to predict the final outcome of HBV infection.