Actions of putative embryokines on development of the preimplantation bovine embryo to the blastocyst stage

Once it enters the uterus at d 4 to 5 after ovulation, the preimplantation bovine embryo is controlled in its development by regulatory signaling molecules from the mother called embryokines. Here, several cell-signaling molecules whose genes are expressed in the endometrium during d 5 to 7 after estrus were tested for the ability to affect the competence of the embryo for further development and the characteristics of the resultant blastocysts. Molecules tested were C-natriuretic peptide (CNP), IL-8, bovine morphogenetic protein 4 (BMP-4), IL-6, and leukemia inhibitory factor (LIF). None of the cell-signaling molecules tested improved the competence of the embryo to become a blastocyst; in fact, BMP-4 decreased development. All molecules modified attributes of the blastocyst formed in culture. In particular, CNP increased the number of cells in the ICM, whereas IL-8 decreased inner cell mass cell numbers and tended to increase the proportion of blastocysts that were hatching or hatched. In addition, BMP-4 decreased the proportion of blastocysts that were hatching. Interleukin-6 and, to a lesser extent, LIF activated the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in the inner cell mass, and LIF increased the percent of cells in the blastocyst that were positive for both NANOG and phosphorylated (activated) STAT3. In conclusion, our results indicate that CNP, IL-8, IL-6, LIF, and BMP-4 can modify embryonic development of the cow in a manner that affects characteristics of the resultant blastocyst. Further research is required to understand how these changes in characteristics of the blastocyst would affect competence of the embryo to establish and maintain pregnancy.

Prevalence of urinary cotinine levels in children under 5 years of age during consultations for acute respiratory disease at the emergency department of the Universidad de La Sabana clinic

BACKGROUND

Several environmental factors favour the occurrence of acute respiratory disease, which is the main reason for paediatric consultations in our country (Colombia). Tobacco smoke is considered a significant environmental pollutant with a great impact on health. The objective of this study is to estimate the prevalence of cotinine levels measured in urine, in children between 1 to 60 months of age who attended an emergency department with acute respiratory disease.

METHODS

A cross-sectional study was conducted that included children between 1 and 60 months of age with acute respiratory disease who were admitted to the emergency department of the Universidad de La Sabana Clinic between April and July 2016.

RESULTS

We included 268 patients and 36% were female. Of the total population examined, 33.96% showed positive results for urinary cotinine, of whom 97.8% had values between 10 and 100 ng/ml, which is considered positive for exposure to second-hand smoke. The principal pathology was recurrent wheezing in 43.96% of these cases. Regarding the presence of smokers at home, it is important to mention that in 54.95% of the children with positive urinary cotinine test was no related with smokers at home. And in 45.05% of positive urinary cotinine was evidence of smokers at home, being associated with the positive result P <  0.001 and smoking within the house P = 0.018; smoking when children were present did not have significant P = 0.105. The activities performed after smoking such as hand washing, change of clothes, eating, brushing teeth, did not influence the test result P = 0.627.

CONCLUSIONS

A high prevalence of urinary cotinine was observed, which is associated with the presence of a smoker at home, and this relationship was independent of the activities performed by the smoker after smoking. In addition, a positive test for urinary cotinine was presented in some children without documented exposure to cigarette smoke inside the home, which may be explained by the presence of environmental cotinine. Therefore, it is necessary to perform educational interventions aimed at parents and caregivers who smoke.

2 Response to Treatment with Human Chorionic Gonadotropin on Pregnancy Rate of Heat-Stressed Lactating Cows: Interactions with Parity and Genotype

Reported effects of treatment of lactating dairy cattle with hCG after AI have been variable. The current objective was to evaluate whether fertility response to hCG in lactating Holsteins exposed to heat stress depends on parity or genotype. The experiment was conducted at a commercial dairy in northern Florida during the summer (June to September). Ovulation was synchronized using the Double Ovsynch protocol for 282 primiparous and 490 multiparous first-service lactating cows. Cows were randomly assigned to receive either 3,300 IU of hCG (Chorulon, MSD, Millsboro, DE, USA) or diluent, IM, on Day 5 after AI. Cows were genotyped by PCR-based KASP assay (LGC Genomics, Middlesex, United Kingdom) for 4 single nucleotide polymorphisms (SNP) previously associated with fertility, embryonic development, or stress tolerance. The SNP were as follows: heat shock protein A1L (HSPA1L, HSP70C895D), prostate androgen-regulated mucin-like protein 1 (PARM1, rs111027720), coenzyme Q9 (COQ9, rs109301586), and progesterone receptor (PGR, rs109506766). Pregnancy diagnosis was performed at Day 60 after AI by ultrasonography. Data were analysed using the GLIMMIX procedure of SAS (SAS Institute Inc., Cary, NC, USA). When genotype was not considered in the model, there was a tendency (P = 0.08) for a treatment × parity interaction, with hCG increasing pregnancy rate in primiparous cows (32.1% ± 0.04 v. 42.0% ± 0.04) but not multiparous cows (27.7% ± 0.02 v. 27.0% ± 0.03). When genotype for COQ9 was included in the model, the parity × treatment interaction was significant (P = 0.036). Moreover, the response to treatment was affected by COQ9 genotype (P = 0.023) and the 3-way interaction (P = 0.060). In cows treated with vehicle, pregnancy rate was greatest for the AA allele (40.2% ± 0.05 for AA, 21.5% ± 0.03 for AG, and 33.3% ± 0.05 for GG). However, for cows treated with hCG, pregnancy rate was lowest for AA (23.5% ± 0.05 for AA, 32.9% ± 0.04 for AG, and 34.0% ± 0.03 for GG). The 3-way interaction occurred because the negative effect of hCG on fertility in AA animals only occurred in multiparous cows. Pregnancy rate was also affected by genotype for HSPA1L (25.0% ± 0.02 for the major allele CC, 38.7% ± 0.04 for CD, and 27.5 ± 0.04 for the minor allele DD; P = 0.003) but there were no interactions with treatment. There was a tendency for pregnancy rate to be affected by genotype for PGR (P = 0.076) but there was no interaction with treatment. The PARM1 genotype was not associated with pregnancy rate. In conclusion, treatment with hCG 5 days after AI improved pregnancy rate in primiparous lactating cows under heat stress but had no effect on pregnancy rate of multiparous cows. Moreover, actions of hCG to improve fertility were associated with a SNP in COQ9. Thus, genotype can affect response of cows to a fertility-promoting drug.

Inhibitory effect of hypergravity on photosynthetic carbon dioxide fixation in Euglena gracilis

Photosynthesis, the conversion of light energy into chemical energy, is a critical biological process, whereby plants synthesize carbohydrates from light, carbon dioxide (CO2) and water. The influence of gravity on this biological process, however, is not well understood. Thus, centrifugation was used to alter the gravity environment of Euglena gracilis grown on nutritive agar plates illuminated with red and blue light emitting diodes. The results showed that hypergravity (up to 10xg) had an inhibitory effect on photosynthetic CO2 fixation. Chlorophyll accumulation per cell was essentially unaffected by treatment; however, Chl a/Chl b ratios decreased in hypergravity when compared to 1xg controls. Photosynthesis in Euglena appears to have limited tolerance for even moderate changes in gravitational acceleration.

The beneficial effects of weekly low-dose vitamin A supplementation on acute lower respiratory infections and diarrhea in Ecuadorian children

BACKGROUND

Previous studies of large-dose vitamin A supplementation on respiratory morbidity have produced conflicting results in a variety of populations. The influence of malnutrition has not been examined in the majority of these trials. We hypothesized that weekly low-dose vitamin A supplementation would prevent respiratory and diarrheal disease morbidity and that malnutrition might influence the efficacy of vitamin A supplementation.

METHODS

In a randomized, double-blind, placebo-controlled field trial of 400 children, 6 to 36 months of age in a high Andean urban slum, half of the children received 10 000 IU of vitamin A weekly and half received placebo for 40 weeks. Children were visited weekly at home by physicians and assessed for acute diarrheal disease and acute respiratory infections.

RESULTS

Acute diarrheal disease and acute respiratory infection did not differ globally or by severity between supplement-treated and placebo groups. However, the incidence of acute lower respiratory infection (ALRI) was significantly lower in underweight (weight-for-age z score [WAZ] <-2 SD) supplement-treated children than in underweight children on placebo (8.5 vs 22.3 per 10(3) child-weeks; rate ratio: 0.38 [95% CI: 0.17-0.85]). ALRI incidence was significantly higher in normal-weight (WAZ >-2 SD) supplement-treated children than in normal-weight children on placebo (9.8 vs 4.4 per 10(3) child-weeks; rate ratio: 2.21 [95% CI: 1.24-3.93]). By logistic regression analysis the risk of ALRI was lower in underweight supplement-treated children than in underweight children on placebo (point estimate 0.148 [95% CI: 0.034-0.634]). In contrast, risk of ALRI was higher in normal-weight supplement-treated children (WAZ >-1 SD to mean) than in normal-weight children on placebo in the same WAZ stratum (point estimate: 2.51 [95% CI: 1.24-5.05]). The risk of severe diarrhea was lower in supplement-treated children 18 to 23 months of age than in children on placebo in this age group (point estimate: 0.26 [95% CI: 0.06-1.00]).

CONCLUSIONS

Weekly low-dose (10 000 IU) vitamin A supplementation in a region of subclinical deficiency protected underweight children from ALRI and paradoxically increased ALRI in normal children with body weight over -1 SD. Protection from severe diarrhea was consistent with previous trials. Additional research is warranted to delineate potential beneficial and detrimental interactions between nutritional status and vitamin A supplementation regarding ALRI.

Risk of diarrheal disease in Ecuadorian day-care centers

To determine the risk for diarrheal disease (DD) in day-care centers (DCC) for children residing in a poor urban slum area of Quito, Ecuador, compared with that for children from the same environment but cared for in their own residential home (RH), a prospective age-, sex- and locale-controlled study of DD was conducted, including 115 children in DCC and 115 in RH, ages 12 to 42 months. The overall incidence of DD was 46/1000 child weeks. Diarrhea was more common in DCC than in RH (relative risk (RR), 1.75; 95% confidence interval (CI), 1.38 to 2.22; P < 0.001). Poor hygienic practices were more prevalent in DCC than in RH. The use of reused water for child handwashing before eating and for washing raw vegetables was associated with a higher risk of DD in DCC than in RH (RR = 4.08, CI 2.93 to 5.67, P < 0.001; RR = 3.90, CI 2.79 to 5.44, P < 0.001, respectively). These two practices were risk factors in the DCC (RR = 2.74, CI 2.08 to 3.68, P < 0.001; RR = 2.05, CI 1.55 to 2.71, P < 0.001, respectively) when compared with their absence in the same DCC. Shigella (RR = 3.58, CI 1.19 to 10.78, P < 0.02), Aeromonas (RR = 10.47, CI 1.35 to 81.05, P < 0.01), rotavirus (RR = 2.86, CI 1.87 to 4.39, P < 0.001) and Giardia (RR = 1.59, CI 1.00 to 2.59, P < 0.05) were more common in DCC than in RH. More than two-fifths of the Shigella and Aeromonas isolates were resistant to trimethoprim-sulfamethoxazole.(ABSTRACT TRUNCATED AT 250 WORDS)

Loss of chloroplast transcripts for proteins associated with photosystem II: an early event during heat-bleaching in Euglena gracilis

A shift in the ratio of chlorophyll (Chl) a and Chl b is an early indicator of heat bleaching in Euglena gracilis. This observation prompted us to consider whether or not changes in steady-state levels of chloroplast transcripts and in transcriptional activity could limit the synthesis of Chl a-binding proteins in bleaching plastids. We found that the mature transcripts for CP47 and CP43, the Chl a-binding apoproteins of the proximal antenna of photosystem II, decline sharply very early during bleaching. Our study also shows that transcription of psbB and psbC, the chloroplast genes encoding CP47 and CP43, remains essentially unchanged during the same interval. We conclude that posttranscriptional events, such as mRNA stability, could play a major role in initiating an irreversible loss of chloroplast function in Euglena at a moderately elevated temperature. Lack of these transcripts would eventually impair the assembly of photosystem II in thylakoids.

Differential involvement of brainstem pathways due to fourth ventricular epidermoid cyst: a case study

A 66-year-old man presented with progressive dysfunction of bilateral cerebellar hemispheres or its connections, corticospinal tracts and medial longitudinal fasciculus (MLF) due to a 4th ventricular epidermoid cyst for the past 47 years. Sensory, auditory and blink reflex pathways were clinically and electrophysiologically normal as indicated by clinical examination and normal median nerve somatosensory evoked responses (SER), brainstem auditory evoked responses (BAER) and blink reflex (BR) studies. These findings were unchanged fifteen months after removal of the lesion. Our findings suggest that (1) in extraaxial brainstem compression, MLF dysfunction can occur, (2) MLF, corticospinal tracts and possibly cerebellum and its connections appear to be more susceptible to longstanding compression and can be selectively and irreversibly damaged whereas pathways located in their vicinity, subserving SER, BAER and BR are spared, and (3) normal clinical and electrophysiological examination of sensory, auditory and BR pathways in presence of abnormal MLF, corticospinal and cerebellar functions should raise a clinical suspicion of an extraaxial brainstem compressive lesion.

Protein Synthesis during the Initial Phase of the Temperature-Induced Bleaching Response in Euglena gracilis

Growing cultures of photoheterotrophic Euglena gracilis experience an increase in chlorophyll accumulation during the initial phase of the temperature-induced bleaching response suggesting an increase in the synthesis of plastid components at the bleaching temperature of 33 degrees C. A primary goal of this work was to establish whether an increase in the synthesis of plastid proteins accompanies the observed increase in chlorophyll accumulation. In vivo pulse-labeling experiments with [(35)S]sodium sulfate were carried out with cells grown at room temperature or at 33 degrees C. The synthesis of a number of plastid polypeptides of nucleocytoplasmic origin, including some presumably novel polypeptides, increased in cultures treated for 15 hours at 33 degrees C. In contrast, while synthesis of thylakoid proteins by the plastid protein synthesis machinery decreased modestly, synthesis of the large subunit of the enzyme ribulosebisphosphate carboxylase was strongly affected at the elevated temperature. Synthesis of novel plastid-encoded polypeptides was not induced at the bleaching temperature. It is concluded that protein synthesis in plastids declines during the initial phase of the temperature response in Euglena despite an overall increase in cellular protein synthesis and an increase in chlorophyll accumulation per cell.

Induced Changes in Chloroplast Protein Accumulation during Heat Bleaching in Euglena gracilis

When growing cultures of light-grown Euglena gracilis Z are exposed to slightly elevated temperatures (33 degrees C) there is a time-dependent decrease in chlorophyll (bleaching) and a gradual transformation of chloroplasts into rudimentary plastids. A study was undertaken whose primary objective was to document major changes in polypeptide composition in the stroma and in thylakoids of cells that have been exposed to the bleaching temperature for up to 57 hours. A novel polypeptide of about 60,000 to 63,000 M(r) whose function is presently unknown, accumulates in the stroma and in thylakoids in response to growth at the bleaching temperature. The levels of the large and small subunit of ribuolosebisphosphate carboxylase, on the other hand, decrease to very low levels at about 33 hours and remain very low for the duration of the temperature treatment. Of two polypeptides associated with the light-harvesting chlorophyll-protein complex of photosystem II (28,000 and 24,500 M(r)) only the level of the smaller polypeptide decreases at the elevated temperature. The levels of 28,000 M(r) species remain virtually unchanged throughout the temperature treatment period. Changes in chloroplast polypeptide composition were also studied in cells that were allowed to recover at room temperature from an initial treatment at 33 degrees C. Bleaching Euglena could provide a useful tool for studying the interaction between the nucleus and chloroplast genetic system that govern the development and maintenance of this vital organelle to plants.

Identification of a 19-kDa polypeptide as an Fe-S center apoprotein in the photosystem I primary electron acceptor complex

Treatment of Photosystem I (PSI) with sodium thiocyanate, a chaotropic agent, results in the selective depletion of certain low-molecular-weight polypeptides. A PSI complex obtained following treatment with 0.5 M sodium thiocyanate is significantly depleted of polypeptides of approximately 8, 10, 14, and 16 kDa, relative to an untreated control, but retains approximately 90% of the EPR signal amplitude associated with the iron-sulfur Centers A and B. The only peptides remaining that could not be depleted without a parallel decrease in the signal amplitude of the Fe-S Centers A and B are the 62-kDa reaction center-containing polypeptide and a 19-kDa polypeptide. These results are considered in relation to the identity of the apoprotein of the Fe-S Centers A and B.

Topographical studies of the polypeptide subunits of the thylakoid cytochrome b6-f complex

The orientation of specific polypeptides of the cytochrome b6-f complex with respect to the chloroplast stromal phase has been studied using trinitrobenzenesulfonate (TNBS) and pronase E as impermeant modifying reagents. Of the four polypeptides of the complex (33,23,20 and 17 kDa), only cytochrome f was labeled by 14C-TNBS in unfractionated membranes. However, to a varying degree, all of the constituent polypeptides were sensitive to pronase digestion and, in the case of cytochrome f, it was possible, by immunoblotting techniques to identify several degradation products. These results are discussed in relation to the organization of the cytochrome complex in thylakoid membranes and argue for an exposure to the stromal phase of all of the polypeptides, while functional considerations indicate that at least cytochrome f and the Rieske iron-sulfur protein have a possible transmembrane organization.

Topography of the protein complexes of the chloroplast thylakoid membrane : studies of photosystem I using a chemical probe and proteolytic digestion

The transverse heterogeneity of the polypeptides associated with the Photosystem I (PSI) complex in spinach thylakoid membranes and in a highly resolved PSI preparation has been studied using the impermeant chemical modifier, 2,4,6-trinitrobenzenesulfonate (TNBS) and the proteolytic enzyme, Pronase E. The present study has shown that the PSI reaction center polypeptide of approximately 62 kilodaltons and the 22 and 20 kilodalton polypeptides of the PSI light-harvesting chlorophyll protein (LHCPI) complex are not labeled by [(14)C]TNBS in unfractionated thylakoids. On the other hand, the 23 kilodalton polypeptide of the PSI LHCP and the 19 and 14 kilodalton polypeptides associated with the PSI primary electron acceptor complex are readily labeled by [(14)C]TNBS and are exposed to the stromal side of the thylakoid. Differences and similarities in the labeling of polypeptides associated with the PSI complex in thylakoids and in the isolated PSI complex are also noted. Treatment of thylakoids with pronase had no effect on the organization of the polypeptides in the LHCPI or the reaction center core complex, as manifested by the separation of these two subcomplexes from pronase-treated membranes. The 62, 19, and 14 kilodalton polypeptides associated with the reaction center core complex and the 23 and 22 kilodalton polypeptides associated with LHCPI are sensitive to pronase treatment while the 20 kilodalton polypeptide of LHCPI was inaccessible to the protease. The proteolysis of the 62 kilodalton polypeptide generated first a single immunodetectable fragment at about 48 kilodaltons, and further proteolytic digestion generated two other fragments at 30 and 17 kilodaltons respectively. These results are discussed in relation to the organization of the PSI complex in spinach thylakoids. A model for the transmembrane topography of the polypeptide constituents of PSI has been developed.

Photosynthetic activity of isolated chloroplasts from Euglena gracilis

Functional chloroplasts from photoheterotrophic Euglena gracilis can be isolated in isoosmotic gradients of 10-80% Percoll. The chloroplasts display rates of CO2 dependent O2 evolution and CO2 fixation of 30-50 μmol mg(-1) chlorophyll h(-1) or 25-35% of the net O2 evolution by the whole cells and appear to be strikingly different from spinach chloroplasts in several respects: 1. tolerance to high concentration of orthophosphate in the assay medium; 2. inability to support oxaloacetate-dependent O2 evolution; 3. ability to support only low to moderate rates of 3-phosphoglycerate-dependent O2 evolution; 4. an apparent absence of a phosphate translocator in the terms described by Heldt and Rapley ([1970] FEBS Lett. 10, 143-148).

Preparation of chloroplasts from euglena highly active in protein synthesis

Chloroplasts can be obtained by gentle lysis or mild shear of spheroplasts of vitamin B(12)-deficient Euglena gracilis and then purified by isopycnic sedimentation on gradients of Ludox AM or Percoll. The chloroplasts appear compact and highly refractile by phase contrast or Hoffmann contrast microscopy. Upon incubation with [(3)H]leucine or [(35)S]methionine, the chloroplasts incorporate the amino acids into protein at rates that are 100-fold faster than we had previously observed with Euglena and up to 8-fold faster than with chloroplasts of spinach. Euglena chloroplasts prepared by the current procedure are thus qualitatively superior to those previously available from Euglena and at least as active in protein synthesis as chloroplasts from higher plants.