Second Month Of Gestation Research Articles

A Comparative Analysis of the Gene Expression Profiles in the Mammary Glands of Lactating and Nonlactating Mares at the Second Month of Gestation.

To investigate molecular regulation involved in lactation during pregnancy, this study focused on the transcriptomic profiles of mammary tissue from lactating and non-lactating Mongolian mares at the second month of gestation. A total of 4197 differentially expressed genes were identified by comparing mammary tissues from pregnant mares at two different states, including 1974 differentially expressed genes such as the milk protein-related genes a-s1-casein (CSN1S1), k-casein (CSN3), lactalbumin (LALBA), and lactoferrin (LTF), which were highly expressed in the lactating mares group, and overall, these differentially expressed genes were mainly associated with biological processes such as endoplasmic reticulum protein processing, the Toll-like receptor signaling pathway, steroid biosynthesis, cytokine-cytokine receptor interactions, and amino sugar and nucleotide glycolysis. These findings serve as a foundation for investigating the molecular underpinnings of lactation in pregnant equids.

Histogenesis of the cornea in sheep fetuses

In this study, 36 samples of sheep fetuses at different ages were used. After preparation and determination of age, the samples were immediately fixed and subjected to gross anatomy and histology examination. In addition to routine H&E staining, two specific staining methods, Verhoeff and Masson's trichrome, were used in the histological study. The results showed that the corneal forming layer completely loses its contact with the lens and posterior layers and the eyelid ridges start to emerge at around 30 days of gestation. However, the cornea becomes fully differentiated in the second month of gestation and only undergoes growth stages in subsequent ages. From the beginning, the cornea in sheep fetuses is formed as a horizontal ellipse, with its inner curvature larger than its outer curvature. The growth process in terms of dimensions, including longitudinal diameter, transverse diameter, and corneal height, shows a regular ascending trend with increasing age. The upper and lower eyelids fuse in early second month and separate again in late third month. The third eyelid appears at approximately 120 days of gestation in the inner angle of the eye. The outer epithelial covering of the cornea changes from simple cuboidal to stratified squamous epithelium. With increasing age, the matrix is strengthened both in terms of cellular components (fibroblasts) and fibers (collagen). Additionally, an increase in elastic fibers is noticeable in the late fetal stages. The Descemet's membrane appears as an inner limiting membrane beneath the inner epithelial covering in early second month and also undergoes growth with increasing age. Descemet's membrane lacks elastic fibers. Bowman's layer or the outer limiting membrane was not observed in this animal. Masson's trichrome staining confirms the growth of collagen fibers, while Verhoeff staining confirms the growth of elastic fibers with increasing age.

Is pregnancy loss initiated by embryonic death or luteal regression? Profiles of pregnancy-associated glycoproteins during elevated progesterone and pregnancy loss

Because progesterone (P4) is essential for pregnancy establishment and maintenance, we investigated the effect of increased concentrations of P4 on embryonic attachment and concentrations of pregnancy-associated glycoproteins (PAG). Additionally, we investigated the relationships among luteal regression, pregnancy loss, and PAG concentrations in cows undergoing pregnancy loss by d 33 of pregnancy. Lactating dairy cows were allocated into control (n = 40) and human chorionic gonadotropin (hCG; 3,300 IU on d 7 and 13 to promote greater circulating P4; GnRH = d 0; n = 46) groups. Progesterone was measured daily from d 7 to 33, and PAG was measured daily from d 17 to 33; both hormones were also measured on d 47 and 61. An increase in PAG >10% compared with d 17 was considered a marker for pregnancy. The gold standard for pregnancy diagnosis was ultrasound evaluation of embryonic heartbeat on d 33. Statistical analyses were done with PROC MIXED from SAS Institute Inc. Concentrations of P4 were greater from d 8 onward in the hCG group. Concentrations of PAG did not differ between groups from d 17 to 33, suggesting no effect of increased P4 on hastening embryonic attachment and placental development. Nevertheless, PAG was greater in the hCG group on d 47 and 61, suggesting greater placental area or PAG secretory capacity. Pregnancy loss between d 20 and 33 occurred in 24.6% of cows. About 50% of pregnancy loss was due to luteal regression and about 50% was due to conceptus failure; that is, a decrease in PAG in the absence of luteal regression. In conclusion, increased P4 does not hasten embryonic attachment or early placental development but it leads to increased PAG in the second half of the second month of gestation. Additionally, pregnancy loss seems to be initiated by either corpus luteum regression or conceptus failure.

The Human Meconium Metabolome and Its Evolution during the First Days of Life.

Meconium represents the first newborn stools, formed from the second month of gestation and excreted in the first days after birth. As an accumulative and inert matrix, it accumulates most of the molecules transferred through the placenta from the mother to the fetus during the last 6 months of pregnancy, and those resulting from the metabolic activities of the fetus. To date, only few studies dealing with meconium metabolomics have been published. In this study, we aimed to provide a comprehensive view of the meconium metabolic composition using 33 samples collected longitudinally from 11 healthy newborns and to analyze its evolution during the first 3 days of life. First, a robust and efficient methodology for metabolite extraction was implemented. Data acquisition was performed using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS), using two complementary LC-HRMS conditions. Data preprocessing and treatment were performed using the Workflow4Metabolomics platform and the metabolite annotation was performed using our in-house database by matching accurate masses, retention times, and MS/MS spectra to those of pure standards. We successfully identified up to 229 metabolites at a high confidence level in human meconium, belonging to diverse chemical classes and from different origins. A progressive evolution of the metabolic profile was statistically evidenced, with sugars, amino acids, and some bacteria-derived metabolites being among the most impacted identified compounds. Our implemented analytical workflow allows a unique and comprehensive description of the meconium metabolome, which is related to factors, such as maternal diet and environment.

265 Awardee Talk: Maternal and Paternal Contributions to Fertility

Abstract Using over 56,000 pregnancy diagnostic records in beef cattle, a meta-analysis was conducted to objectively determine that 28.4 % of embryos will not develop past day 7 of gestation with most embryonic losses occurring before day 4. Furthermore, by day 30 of gestation, 47.9 % of cows submitted to a single insemination at day 0 will not be pregnant and pregnancy loss between days 32 and 100 was 5.8%. Reproductive success, however, is highly variable and influenced by maternal and paternal factors. Maternal characteristics, including subspecies, parity and reproductive tract size, intersect with breeding management decisions regarding estrus expression and detection to influence conception and pregnancy rates. The maternal endocrine environment, from estradiol associated with estrus around fertilization to elevated prostaglandins during the embryonic to fetal transition period, play critical roles in pregnancy success. Despite the numerous maternal factors involved with pregnancy establishment, sire contribution to reproductive failure should not be overlooked. Sires are reported to influence pregnancy loss during the second month of gestation in both beef and dairy herds. These differences in sire field fertility could not be explained by differences in semen characteristics nor differences in sire conception rate (SCR) score. To understand parental contribution to pregnancy development during the second month of gestation we developed parthenogenetic (PA) embryos (embryos lacking paternal genome). We observed that PA conceptus had well developed trophectoderm tissue at day 31 of gestation but no site of embryo attachment to the endometrium. Moreover, conceptus secretion such as pregnancy-associated glycoproteins and interferon-stimulated genes were not found in maternal circulation. These results suggest that paternal genetics is required for post-elongated embryo attachment to endometrium. Further exploring the maternal vs paternal contribution to pregnancy development can help elucidate the mechanism that drives reproductive failure in cattle.

Reproduction and reproductive tract morphology of male and female pigs whose mothers were heat stressed during the second month of gestation.

The primary objective was to assess the development of fetal gonads and measure the subsequent reproductive capacity of boars and gilts whose mother was either subjected to gestational heat stress (GHS) or thermoneutral (GTN; control) conditions during pregnancy. Gilts were subjected to either GHS (28 to 38 °C; 65% to 88% relative humidity [RH]; n = 30) or GTN (17 to 22 °C; 56% to 65% RH; n = 29) for the second month of gestation (a period that coincides with a critical window of gonadal development). A subset of GHS (n = 12) and GTN (n = 11) gilts was sacrificed immediately following treatment for the collection of pregnancy data. The remaining gilts (n = 18 GHS and n = 18 GTN) were allowed to farrow. Female offspring from the farrowed gilts were studied through puberty, first insemination, and early pregnancy when fetal tissues were again collected. During the treatment period, GHS gilts had greater (P < 0.001) rectal temperature and respiration rate at both measurement time points (morning and afternoon) compared with GTN gilts. When assessed at the end of the second month of gestation, the total number of viable fetuses did not differ (P > 0.10) for GHS vs. GTN. Likewise, the weight of the fetus, placenta, fetal testes, and fetal ovaries were similar (P > 0.10) for GHS and GTN pregnancies. There was a tendency for an effect of treatment (63.3 ± 2.3 vs. 70.1 ± 2.6; GHS vs. GTN; P < 0.073) on the number of oogonia per histological section in the fetal ovaries. There was no effect of treatment on the number of prespermatogonia per histological section in the fetal testis. For gilts farrowing after treatment, litter size, piglet birth weight, and weaning weight were similar (P > 0.10) for the GHS and GTN gilts. Testes collected from castrated GHS boars had fewer prespermatogonia per seminiferous tubule cross section (P < 0.049). Female offspring from the GHS (n = 30) or GTN (n = 37) sows reached puberty at a similar age, and their pregnancies (ninth week of gestation) had fewer corpora lutea (15.6 ± 0.5 vs. 17.1 ± 0.4; GHS vs. GTN; P < 0.038) but the number of fetuses was similar for GHS and GTN. In summary, compared with GTN, GHS during a critical window of gonadal development tended to reduce the number of oogonia in the fetal ovary, reduced the number of prespermatogonia in the neonatal testes, and reduced ovulation rate at first pregnancy in gilts.

Anquiloglossia - da histogênese, e implicações parafuncionais aos aspectos legais: uma revisão bibliográfica

Objetivo: abordar as consequências da anquiloglossia quando não há intervenção precoce, além das implicações legais esperadas. Material e Métodos: este estudo verificou as bases de dados PubMed, Bireme, Google Scholar, Scielo, Lilacs e Medline. Dos 30 artigos encontrados, nove foram descartados por não se identificarem com os objetivos. Resultados: a anquiloglossia é um distúrbio congênito do frênulo lingual que limita a elevação e protrusão da língua devido à sua curta extensão e repercute em todo o sistema estomatognático. Verifica-se na literatura que a língua é totalmente formada no segundo mês de gestação e que o frênulo é formado após apoptose das células de freio linguais e reabsorção do músculo esquelético em desenvolvimento. Portanto, a anquiloglossia é classificada em cinco graus, de acordo com sua mobilidade, e em quatro tipos, de acordo com sua espessura e elasticidade. O Neonatal Tongue Screening Test é aplicado de acordo com uma lei e a não realização deste teste pode levar a consequências anatômicas e funcionais para a mãe e o bebê. O tratamento recomendado é a frenectomia, embora a frenectomia e a Z-Plastia possam ser utilizadas. Conclusão: conclui-se que os profissionais de saúde não devem descuidar do teste, para evitar o agravamento dessa condição.

The effects of leptin on plasma concentrations of prolactin, growth hormone, and melatonin vary depending on the stage of pregnancy in sheep.

The effects of hyperleptinemia and leptin resistance during gestation are unclear. Leptin, an important neuroendocrine regulator, has anorexic effects, but its interactions with other metabolic hormones during pregnancy are unclear. We examined potential roles of leptin in regulating prolactin (PRL), GH, and melatonin plasma concentrations during pregnancy in Polish Longwool ewes. Twelve estrus-synchronized ewes carrying twins after mating were randomly assigned to receive i.v. injections of saline or recombinant ovine leptin (2.5 or 5.0 µg/kg BW). Blood samples were collected (15-min intervals over 4 h) immediately before the first injection at dusk and kept under red light. Treatments were repeated at 2-wk intervals, starting before mating and continuing from days 30 to 135 of gestation. Concentrations of plasma PRL, GH, and melatonin were determined using a validated RIA. The effects of leptin on hormone plasma concentrations varied depending on pregnancy stage and leptin dose. PRL plasma concentrations were affected at most stages of pregnancy and before gestation. In non-, very early- (day 30), and late- (day 120 and 135) pregnant ewes, exogenous leptin stimulated PRL (P < 0.001) plasma concentrations, while during the second month of gestation, it decreased PRL concentrations (P < 0.01). Leptin affected GH plasma concentrations (P < 0.05) only during the first 2 mo of pregnancy, with no effects during the second part of gestation or before pregnancy. In early-pregnant ewes (day 30 and 45), leptin decreased melatonin plasma concentrations (P < 0.05), but at day 60, leptin stimulated melatonin plasma concentrations at low (P < 0.01) and high doses (P < 0.05), with no effects in ewes after 105 d of gestation. These data indicate specific pregnancy-induced endocrine adaptations to changes in energy homeostasis, supporting the hypothesis that leptin affects PRL, GH, and melatonin release during gestation.

New insights in the pathophysiology of complete hydatidiform mole

ObjectiveThe majority of complete hydatidiform moles (CHM) are detected on ultrasound examination by the end of the first trimester when they present as multiple sonolucent cysts. To better understand the pathophysiology of this unique placental pathology and improve its prenatal diagnosis and management we have reviewed the ultrasound features of CHM before the appearance of cystic changes. Study designWe searched our database to identify all women diagnosed with a complete hydatidiform mole confirmed by histopathology who had an ultrasound examination before 9 weeks' gestation. We reviewed their ultrasound reports and all the corresponding images. ResultsThe study group included 39 women with a positive pregnancy test and vaginal bleeding, 36 of whom had at least two ultrasound examinations before 9 weeks' gestation. At the first scan (mean gestation age 7 + 1 weeks; SD 1.1), 29 out 39 (74.4%) of CHM presented as a heterogeneous hyperechogenic mass with or without gestational sac and the remaining ten (25.6%) cases as a regular 4-week gestational sac. Cystic molar changes became apparent from the end of the second month of gestation. ConclusionThe development of a CHM follows a well-defined pattern starting with a macroscopically normal gestation sac at 4 weeks, which transforms into a polypoid mass between 5 and 7 weeks of gestation. The hydropic changes of the villous tissue is progressive and rarely visible in utero on ultrasound before 8 weeks of gestation. These findings should allow an earlier diagnosis and assist in the management counselling of women with CHM.

Pregnancy establishment and maintenance after the administration of equine chorionic gonadotropin (eCG) associated or not with gonadotropin-releasing hormone (GnRH) after insemination in sheep

It was recently demonstrated that equine chorionic gonadotropin (eCG) treatment 10 days after ovulation increases serum progesterone concentrations in sheep. The objective of the present study was to evaluate pregnancy outcomes induced with the administration of eCG and gonadotropin-releasing hormone (GnRH) after insemination. Three experiments were conducted in multiparous ewes that received fixed-time intrauterine insemination (Day 0) after a progesterone-based protocol for oestrus synchronisation. Experiment 1 consisted of 408 ewes, randomly assigned to three experimental groups; ewes in the first and second group received 400 IU of eCG on Day 5 and Day 10 after insemination respectively, while ewes on the third (control) group did not receive eCG. In Experiment 2, 587 ewes were randomly assigned to four experimental groups (2 × 2 factorial experiment), to receive or not 400 IU of eCG on Day 5, associated or not with 100 µg of GnRH analogue on Day 6 (i.e. 30 h after eCG administration). In Experiment 3, 715 ewes were randomly assigned to four experimental groups (2 × 2 factorial experiment), to receive or not 400 IU of eCG on Day 10, associated or not with 100 µg of GnRH analogue on Day 11 (i.e. 30 h after eCG administration). Pregnancy diagnosis was determined on Day 30 and Day 70 by ultrasonography. The eCG treatment after insemination failed to improve pregnancy outcomes in Experiments 1 and 2. However, in Experiment 3 the treatment with eCG on Day 10 enhanced pregnancy rate on Day 30, although this improvement was not maintained on Day 70, which showed greater pregnancy failure. The administration of GnRH on Day 6 or Day 11, preceded or not by eCG, did not affect any of the variables related to pregnancy. In summary, the improvement in progesterone profiles induced by eCG treatment on Day 10 after insemination, previously reported in sheep, seems to have a marginal positive effect on pregnancy establishment during the first month, which is not maintained during the second month of gestation.

Case 1: A Newborn with Acute-Onset Respiratory Distress and Encephalopathy

A term male infant is born to a consanguineous couple by emergency cesarean section for nonprogressive labor. The mother’s antenatal period was uncomplicated. Her first pregnancy resulted in an abortion in the second month of gestation. The newborn’s Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. The infant appears normal soon after birth and formula feeding is started. On the second day, he is noted to have fast breathing for which he is admitted to a local hospital and receives intravenous fluids, antibiotics, and oxygen. However, in view of worsening respiratory distress, the infant is referred to our center on the third day after birth. On admission to our NICU, the infant’s temperature is 97.2oF (36.2oC), he has tachypnea, with a respiratory rate of 90 breaths per minute and minimal intercostal recessions, oxygen saturation is 94% on room air, heart rate is 160 beats per minute, peripheral extremities are warm, capillary refill time is less than 3 seconds, and blood pressure in the right upper limb is 62/29 mm Hg (mean arterial pressure, 40 mm Hg). There is no dysmorphism, weight is 2.7 kg, and head circumference is 36 cm (90th percentile). On systemic examination, the liver edge is felt 3 cm below the right costal margin, and auscultatory …

Biochemical composition and protein profile of alpaca (Vicugna pacos) oviductal fluid

Knowledge and assessment of the constituents of the oviductal fluid (OF) in camelids is necessary for a correct formulation of specific culture media for the development of reproductive biotechnology. This study is the first describing the biochemical composition and SDS–PAGE protein profile of alpaca oviductal fluid in non-pregnant animals and animals that have completed the first month and second month of gestation. Samples were also classified into oviducts that were ipsilateral or contralateral to the ovary with corpus luteum. No differences were found between both oviducts, whereas pregnant and non-pregnant females displayed significant differences in the biochemical composition and protein profile of the oviductal fluid. Relative albumin content was higher in non-pregnant females. Relative creatinine content in OF from females that have completed the second month of gestation was lower than non-pregnant females and females that have completed the first month of gestation. Ion Na+ concentration was higher in OF from non-pregnant females when compared with pregnant ones. The protein profile of non-pregnant females showed five protein bands of 70, 42, 25, 24 and 19kDa that were significantly more intense compared with pregnant animals. Bands were identified as moesin, actin cytoplasmic 2, hydroxypyruvate isomerase, ferritin light chain and peroxiredoxin-6 with MALDI/MS. Our results encourage more thorough future studies, in order to unravel the complex reproductive processes of the South American camelid oviduct.

Incorporation and Reproduction: Public Opinion and Provision of Public Goods to Immigrants

How do the attitudes of bureaucrats affect the implementation of public policy? We argue that the attitudes of strategically placed bureaucrats and service providers affects service provision. To provide empirical support for our argument, we analyze service provision for immigrants specifically because when gatekeeper bureaucrats and service providers view immigrants as more deserving, immigrants will be better able to access public services in general, and health services in particular. Analysis of this questions is important because bureaucrats often have considerable discretion in the actual implementation of public policy. To conduct our analysis, we contend that the events of September 11, 2001 acted as an exogenous shock to the attitudes of bureaucrats towards immigrants. We hypothesize that a change in attitudes towards immigrants caused gatekeeper bureaucrats to reevaluate whom they judged to be the most deserving recipients of health services in the period following September 11, 2001. The discontinuity is visible 7 months after September 11 in April, 2002, reflecting that mothers begin care on average during the second month of gestation. Being both foreign born and Hispanic is associated with the largest change in service provision, relative to other groups.

The influence of experimental infection of gilts with swine H1N2 influenza A virus during the second month of gestation on the course of pregnancy, reproduction parameters and clinical status.

BackgroundThe course of swine influenza in pigs is reported to be similar to human influenza. Occasionally abortions and other reproduction disorders have been associated with influenza A virus (IAV) infection in pigs. Abortions may be a consequence of high fever, pro-inflammatory cytokines or transplacental transmission of the virus.The role of IAV in the complications observed during pregnancy has been scanty and the true importance of this agent as a cause of reproductive problems in swine is not known. The aim was to determine the possible involvement of swine H1N2 IAV strain on reproductive disorders in pregnant gilts under experimental conditions.ResultsThe gestation length was from 113 to 116 days, no abortion or any other reproduction disorders were noted. A PCR assay confirms the presence of IAV in the nasal swabs taken from inoculated gilts between 1 and 5 dpi. In the nasal swabs from control gilts and newborn piglets, no IAV genetic material was found. No viral RNA was detected in samples of blood taken from gilts and piglets, placentas, lungs and tracheas taken from piglets euthanized after delivery. The significant decrease in the number and percentage of lymphocytes without leukopenia was observed at 4 dpi in inoculated gilts. The percentage of granulocytes increased significantly at 4 dpi in inoculated pigs. The concentration of IL-6, IL-10 and TNF-α were higher in inoculated gilts, while IL-4 and IFN-γ were not detected in the serum of any of animals. The serum concentrations of C-reactive protein remained stable during study, while haptoglobin concentrations increased significantly after inoculation.ConclusionsThe results of the study indicate that infection of pregnant gilts with swine H1N2 IAV in the second month of pregnancy does not cause abortion and other reproduction disorders. No evidence for transplacental transmission of swine H1N2 IAV was found. However, due to subclinical course of influenza in the present experiment caution should be taken in extrapolating these results to the cases of acute influenza. The other limitation is IAV diversity. It cannot be excluded that other subtypes of IAV could be associated to reproduction failure in pigs.

Syndromic craniosynostosis, fibroblast growth factor receptor 2 (FGFR2) mutations, and sacrococcygeal eversion presenting as human tails

There have been 23 previously published cases of patients with syndromic craniosynostosis and human tails. In many of these, the tail was composed of prominent coccygeal and sacral vertebrae, curved in a retroverted instead of in the normal anterograde fashion. This has been termed sacrococcygeal eversion. In those cases in which genetic testing results are reported, there were fibroblast growth factor receptor 2 (FGFR2) mutations. We present three patients with Pfeiffer syndrome and sacrococcygeal eversion. Two had genetic testing and both had FGFR2 mutations, one of them a novel mutation in patients with syndromic craniosynostosis and sacrococcygeal eversion. We also briefly review the literature on craniosynostosis and human tails. All but one reported patient has had either Pfeiffer, Crouzon, or Beare-Stevenson syndrome. Most patients, including ours, have had severe manifestations of their syndrome. Although the pathogenesis of sacrococcygeal eversion is unknown, a similarly posteriorly curved tail bud develops in normal human embryos during the second month of gestation. Perhaps increased FGFR2 activation during this embryonic period leads to abnormal differentiation or regression of the tail bud and, in turn, sacrococcygeal eversion, in certain patients with severe syndromic craniosynostosis.

Pancreas Divisum – more than a rare cause of recurrent pancreatitis

Pancreas divisum (PD) is the most common congenital variant of pancreatic duct anatomy. It occurs in approximately 6%-10% of healthy individuals. In embryonic period, during second month of gestation, the ventral and dorsal pancreatic ducts fail to fuse. This failure forces the dorsal pancreatic duct and minor papilla to become the major drainage channel for pancreatic exocrine secretion. Only a minority of patients with PD develop pancreatitis. The objective was to give an example of causal relationship between PD and pancreatitis. It has been the subject of controversy, although most authors agree that PD is a definite cause in a subgroup of patients. A 13-year-old boy was admitted to our institution for recurrent acute pancreatitis. In the period of one year, he was admitted twice for recurrent acute pancreatitis. On admission, no symptoms were reported, except for minor epigastric tenderness. Family history concerning pancreatitis and other gastrointestinal diseases was unremarkable. Clinical examination, laboratory and radiology diagnosis were performed. Laboratory blood test results were within the standard range. Magnetic resonance cholangiopancreatography demonstrated separation of the pancreatic ducts, i.e. pancreas divisum. In the perisplenic area, residues of earlier inflammation were noted. We were able to confirm the causal relationship between PD and pancreatitis. Treatment consists of endoscopic interventions with prophylactic temporary stenting or surgical care. The probable factor that promotes recurrent acute pancreatitis in pancreas divisum is relative stenosis of the minor duodenal papilla.

Exposure to air pollution in critical prenatal time windows and IgE levels in newborns

The objective of this study was to analyze the mechanisms by which exposure to ambient air pollutants influences respiratory health may include altered prenatal immune development. To analyze associations between elevated cord serum Immunoglobulin E (IgE) levels and maternal air pollution exposure during each month of gestation. Total cord serum IgE was determined by the CAP system and mothers' total IgE levels by nephelometry for 459 births in the Czech Republic from May 1994 to mid-January 1997. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and particulate matter <2.5 microns in diameter (PM(2.5) ) were measured in ambient air, and arithmetic means were calculated for each gestational month. Log binomial regression models were used to estimate prevalence ratios (PR) for elevated cord serum IgE (≥0.9 IU/ml) adjusting for district of residence, year of birth, and in further models, for maternal IgE (a surrogate for atopy) and gestational season. Heterogeneity by maternal atopy status was evaluated for associations of air pollution and of cigarette smoke. In adjusted models, PAH and PM(2.5) exposures in the second month of gestation were each associated with a lower prevalence of elevated cord serum IgE. For an average increase of 100 ng/m(3) of PAHs, the PR was 0.69 (95% confidence interval (CI): 0.50, 0.95); for 25 μg/m(3) increase in PM(2.5) , the PR was 0.77 (95% CI: 0.55, 1.07). Conversely, exposures later in gestation were associated with a higher prevalence of elevated cord IgE: in the fifth month, the PR for PAH exposure was 1.64 (95% CI: 1.29, 2.08), while for PM(2.5) in the sixth month, it was 1.66 (95% CI: 1.30, 2.13). In analyses stratified by maternal atopy, air pollutants were associated with altered cord serum IgE only among neonates with non-atopic mothers. Similarly, an association of cigarette smoke with elevated cord serum IgE was found only in non-atopic mothers. PAHs and PM(2.5) , constituents of both ambient air pollution and cigarette smoke, appear to influence fetal immune development, particularly among infants whose mothers are not atopic.

Effects of the absence of protozoa from birth or from weaning on the growth and methane production of lambs

Merino ewes (n 108) joined to a single sire were allocated into three flocks, with ewes in one flock being chemically defaunated in the second month of gestation. Single lambs born to defaunated ewes (BF lambs) were heavier at birth and at weaning than lambs born to faunated ewes (F lambs). After weaning, all BF and F lambs were individually housed then half of the F lambs were chemically defaunated (DF lambs). In trial 1, BF, DF and F lambs were offered a concentrate-based diet containing either 14 or 19 % protein for a 10-week period. Wool growth rate of BF lambs was 10 % higher than that of DF or F lambs and was increased 9 % by the high-protein diet. While there was no main effect of protozoa treatment on enteric methane production, there was an interaction between protozoa treatment and diet for methane production. BF and DF lambs produced more methane than F lambs when fed the low-protein diet but when fed the high-protein diet, emissions were less than (BF lambs) or not different from (DF lambs) emissions from F lambs. In trial 2, lambs were offered 800 g roughage per d and, again, methane production was not affected by the presence of protozoa in the rumen. The data indicate that while lambs without rumen protozoa have greater protein availability than do faunated ruminants, there is no main effect of rumen protozoa on enteric methane production by lambs fed either a concentrate or roughage diet.

Embryonic Cardiac Morphometry in Carnegie Stages 15–23, from the Complutense University of Madrid Institute of Embryology Human Embryo Collection

Aims: We performed a morphometric study of cardiac development on human embryos to complement the scarce data on human embryonic cardiac morphometry and to attempt to establish, from these, algorithms describing cardiac growth during the second month of gestation. Methods: Thirty human embryos from Carnegie stages 15–23 were included in the study. Shrinkage and compression effects from fixation and inclusion in paraffin were considered in our calculations. Results: Growth of the cardiac (whole heart) volume and volume of ventricular myocardium through the Carnegie stages were analysed by ANOVA. Linear correlation was used to describe the relationship between the ventricular myocardium and cardiac volumes. Comparisons of models were carried out through the R² statistic. The relationship volume of ventricular myocardium versus cardiac volume is expressed by the equation: cardiac volume = 0.6266 + 2.4778 volume of ventricular myocardium. The relationship cardiac volume versus crown-rump length is expressed by the equation: cardiac volume = 1.3 e^{0.126 CR length}, where e is the base of natural logarithms. Conclusion: At a clinical level, these results can contribute towards the establishment of a normogram for cardiac development, useful for the design of strategies for early diagnosis of congenital heart disease. They can also help in the study of embryogenesis, for example in the discussion of ventricular trabeculation.

The changing cellular environments of hematopoiesis in human development in utero

The hematopoietic system is indispensable from the earliest stages of development and adapts to the rapidly changing anatomy of the embryo and fetus; this takes place in such different anatomic locations as the yolk sac blood island, hepatic parenchyme, aorta-gonads-mesonephros paravascular mesenchyme, and bone marrow primary logette. We herein summarize our investigation of these serial blood-forming events in the human embryo and fetus. The access to early stages of human development, availability of a large panoply of molecular markers for human blood cell lineages, and recent development of robust assays for the earliest human hematopoietic stem cells have allowed us to gain relatively clear insight into the developmental sequence that underlies the ontogeny of human blood cells. Conversely, the control exerted by these diverse cellular environments on the emergence of human hematopoietic cells remains elusive, as is the case in animal models. We nonetheless present preliminary attempts to decipher the structure and molecular characteristics of the distinct cellular "niches" in which blood cells are produced during human gestation.