116 research outputs found
Developmental programming: the role of growth hormone
Developmental programming of the fetus has consequences for physiologic responses in the offspring as an adult and, more recently, is implicated in the expression of altered phenotypes of future generations. Some phenotypes, such as fertility, bone strength, and adiposity are highly relevant to food animal production and in utero factors that impinge on those traits are vital to understand. A key systemic regulatory hormone is growth hormone (GH), which has a developmental role in virtually all tissues and organs. This review catalogs the impact of GH on tissue programming and how perturbations early in development influence GH function
Developmental regulation of corticotrophin receptor gene expression in the adrenal gland of the ovine fetus and newborn lamb: Effects of hypoxia during late pregnancy
Responsiveness of the fetal Sheep adrenal gland to adrenocorticotrophin (ACTH) increases in late pregnancy, resulting in increased glucocorticoid production. Development of this responsiveness is an important determinant of fetal hypothalamic-pituitary-adrenal function and depends, in part, on the potential for ACTH binding to adrenal tissue. In the present study, we have examined the developmental pattern of ACTH receptor (ACTH-R) expression during the latter half of pregnancy and in neonatal and adult life. As hypoxaemia induces increases in cortisol and ACTH secretion, in addition to increasing fetal adrenal responsiveness, a further aim of this study was to investigate whether hypoxaemia was associated with altered expression of the ACTH-R gene.
Whole adrenal glands were removed from fetal sheep, lambs and adult sheep at different stages of development for measurement or ACTH-R mRNA. Moderate hypoxaemia was induced for 48 h beginning on days 124-128, or on days 131-134 of gestation, by decreasing the maternal fractional inspired oxygen. ACTH-R mRNA was detected northern blotting using a cDNA cloned in our laboratory and by in situ bydridisation.
ACTH-R mRNA (3.6 kb major transcript) was detected in adrenal tissue at day 63 of gestation. Its relative abundance increased significantly (P<0.05) between days 126-128 and 140-141 of pregnancy, increased further with the onset of spontaneous labour, and remained increased in newborn lambs at 7 h-7 days after birth. ACTH-R mRNA levels then decreased ill adrenal tissue from lambs and adult sheep (P<0.05). Hypoxaemia for 48 h significantly increased ACTH-R mRNA expression in adrenals of the older fetuses (days 134-136) compared with that in controls (P<0.05), but was without effect in younger fetuses.
We conclude that levels of ACTH-R mRNA ill the fetal adrenal gland increase as term approaches, coincident with the endogenous prepartum surge in plasma ACTH and cortisol. Sustained hypoxaemia resulted in an upregulation of mRNA encoding for ACTH-R, but only in older fetuses and in association with a sustained increase in plasma cortisol. These results are consistent with cortisol, ACTH, or both, contributing to increased fetal adrenal responsiveness, by increasing expression of fetal adrenal receptors for ACTH
Guaranteed Nonlinear Estimation Using Constraint Propagation on Sets
Bounded-error estimation is the estimation of the parameter or state vector of a model from experimental data, under the assumption that some suitabl y de...ned errors shoul d bel ong to some prior feasibl e sets. When the model outputs arel inear in the vector to be estimated, a number of methods are avail#0 l e to encl ose al# estimates that are consistent with the data into simpl# sets such as el# ipsoids, orthotopes or paral#0xP90O es, thereby providing guaranteed set estimates. In the nonl#x]30 case, the situation is muchl#O4 devel#O ed and there are very few methods that produce such guaranteed estimates. In this paper, the discrete-time probl em is cast into the more general framework of constraint satisfaction probl ems.Al# orithms rathercl assical in the area of interval constraint propagation are extended by repl acing interva l# by moregeneral subsets of real vector spaces. This makes it possibl# to propose a new al#9Oq30 m that contracts the feasibl e domains for each uncertain variabl# optimal#O (i.e., no smal# er domain coul d be obtained) and ecientl# . The resul ting methodol#03 isil#34 trated on discrete-time nonl#O0O7 state estimation. The state at time k is estimated either from past measurement onl y or from al l measurements assumed to be avai l#bl# from the start. Even in the causal case, prior information on the future val# e of the state and output vectors, due for instance to physical constraints, is readil y taken into account
Developmental regulation of preproenkephalin (PENK) gene expression in the adrenal gland of the ovine fetus and newborn lamb: effects of hypoxemia and exogenous cortisol infusion
Development of the fetal adrenal gland is crucial not only for maturation of several fetal organ systems and the initiation of parturition, but also for the development of the fetal response to stress. The enkephalin-related peptides are present in the chromaffin cells of the fetal adrenal medulla and are secreted in response to stress and with sympathetic stimulation. However, changes in expression of preproenkephalin (PENK) with gestation and in response to stress have not been studied in detail. Therefore we examined the developmental pattern of PENK gene expression in the adrenal gland of fetal and newborn lambs, and of adult sheep. We also determined whether levels of PENK mRNA in the fetal adrenal gland changed in response to exogenous glucocorticoids in late gestation, or in response to hypoxemia.
Adrenal glands were removed from fetal sheep, lambs and adult sheep at different stages of development for measurement of PENK mRNA. Cortisol was infused (5 mu g/min) for 12, 24 or 96 h beginning on day 124-129 of gestation. Moderate hypoxemia was induced for 48 h beginning on day 126-130, or at day 134-136 of gestation, by lowering the maternal fractional inspired oxygen. At the end of the treatment periods, the ewes and fetuses were euthanized. Adrenal PENK mRNA were measured by Northern blot analysis. PENK mRNA levels in fetal adrenals were significantly higher (P<0.05) on days 140-141 of gestation than earlier in pregnancy, and then decreased significantly with the onset of parturition (days 142-146), After cortisol infusion to the fetus for 96 h there was a significant reduction in adrenal PENK mRNA levels. Hypoxemia resulted in a significant increase in PENK mRNA levels in fetuses at day 126-130 of gestation, but not at the later time in pregnancy when endogenous plasma cortisol concentrations were higher.
We conclude that there is a decrease in levels of PENK mRNA in the fetal adrenal gland before parturition at the time of the endogenous prepartum rise in plasma cortisol. Hypoxemia led to an elevation of PENK mRNA levels in fetuses at less than 130 days, but after that time, when the basal and stimulated cortisol responses had risen, there was no significant effect of hypoxemia on PENK mRNA. Cortisol infusion to the fetus at this stage of pregnancy resulted in a decrease in adrenal PENK mRNA levels. We suggest that cortisol may play an important role in the regulation of fetal adrenal PENK mRNA levels and enkephalin synthesis by the adrenal gland of the fetal sheep
Mesonephric adenocarcinoma of the cervix: Case report and literature review
A mesonephric adenocarcinoma of the cervix is a very rare tumor deriving from remnants of the mesonephric duct. Differential diagnosis from other cervical carcinomas is difficult and little is known regarding its biological behavior, prognosis, and the optimal management strategy. We present a case of a mesonephric adenocarcinoma of the cervix with a comprehensive review of the existing literature. In this case a 66-year-old woman presented with postmenopausal vaginal bleeding. She was diagnosed with a FIGO stage IIB mesonephric adenocarcinoma of the cervix and treated with neoadjuvant chemoradiotherapy and a Wertheim hysterectomy. The recovery from surgery was uneventful and the patient remains with no evidence of disease with 2Â years of follow-up
Expression of cell adhesion molecules in the extravillous trophoblast is altered in IUGR
PROBLEM: The invasion of trophoblast cells into the uterine wall and its arterial system is essential for the normal development of pregnancy. Cell adhesion molecules (CAM), such as the immunoglobulin superfamily and integrins, play a crucial role in a number of immunological reactions and in the invasion of the human trophoblast. Intrauterine growth restriction (IUGR) has been associated with abnormal trophoblast invasion. Therefore, the expression of CAM in the extravillous trophoblast of pregnancies complicated by IUGR might be different from normal pregnancies.
METHOD OF STUDY: Normal (n = 21) and IUGR (n = 19) placentas were collected and stored at -70 degrees C. Immunohistochemistry (avidin-biotin complex peroxidase-doublestaining) of frozen tissue sections was performed using antibodies specific for the immunoglobulin superfamily vascular adhesion molecule-1 (VCAM-1;CD 106), intercellular adhesion molecule (ICAM-1) (CD 54), ICAM-2 (CD 102), ICAM-3 (CD 50), the integrins alpha 2 beta 1, alpha 3 beta 1, alpha 4 beta 1, alpha 5 beta 1, alpha 6 beta 1 and cytokeratin. The percentage of immunopositive extravillous trophoblast cells (EVT) and the intensity of the immunoreactivity for the various CAM and integrin antibodies was assessed.
RESULTS: In IUGR placentas, there was less expression of VCAM-1 (CD 106), alpha 2 beta 1, alpha 3 beta 1, and alpha 5 beta 1 (P < 0.05) in the extravillous trophoblast than in normal pregnancies. Finally we observed for the first time that ICAM-3 was expressed on EVT and that its expression was markedly up-regulated in the EVT of IUGR placentas. No differences were found for ICAM-1 (CD 54), ICAM-2 (CD 102), alpha 4 beta 1 and alpha 6 beta 1.
CONCLUSION: Our data show that there are significant differences in the expression of cell adhesion molecules of the extravillous trophoblast from IUGR and normal pregnancies. These differences might reflect changes in the immunological reactions and cell-cell interactions between mother and the developing fetus which could interfere with fetal growth
Exploring tick saliva: from biochemistry to ‘sialomes’ and functional genomics
Tick saliva, a fluid once believed to be only relevant for lubrication of mouthparts and water balance, is now well known to be a cocktail of potent anti-haemostatic, anti-inflammatory and immunomodulatory molecules that helps these arthropods obtain a blood meal from their vertebrate hosts. The repertoire of pharmacologically active components in this cocktail is impressive as well as the number of targets they specifically affect. These salivary components change the physiology of the host at the bite site and, consequently, some pathogens transmitted by ticks take advantage of this change and becomemore infective. Tick salivary proteins have therefore become an attractive target to control tick-borne diseases. Recent advances inmolecular biology, protein chemistry and computational biology are accelerating the isolation, sequencing and analysis of a large number of transcripts and proteins from the saliva of different ticks. Many of these newly isolated genes code for proteins with homologies to known proteins allowing identification or prediction of their function. However, most of these genes code for proteins with unknown functions therefore opening the road to functional genomic approaches to identify their biological activities and roles in blood feeding and hence, vaccine development to control tick-borne diseases
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