Developmental toxicity of cysteamine in the rat: effects on embryo-fetal development

The reproductive and developmental safety of cysteamine has become an important issue to children with cystinosis because renal transplants and treatment with cysteamine reduce the complications associated with cystinosis and increase the lifespan of the affected children. In addition, there is the potential to decrease the severity or the incidence of renal Fanconi syndrome with administration of cysteamine to pregnant women carrying fetuses with cystinosis, and to ease significantly the burden of this disease throughout their lives. If cysteamine increases significantly the risk of fetal death, growth retardation or birth defects at doses used to treat women with cystinosis, treatment of the affected female should cease during pregnancy and would not be considered for fetal treatment. The goal of this study was to assess the developmental safety of exposure in utero to cysteamine in the rat. Pregnant rats were given cysteamine (as phosphocysteamine) from day 6.5 through day 18.5 postconception and fetuses were assessed for survival, growth, and structural abnormalities on day 20.5. Cysteamine was administered orally in doses of 0, 37.5, 75, 100, or 150 mg/kg/day. Cysteamine produced dose-dependent developmental toxicity with an apparent no adverse effect observed level of 75 mg/kg/day. Specific malformations were associated with this effect (cleft palate, kyphosis), as well as intrauterine growth retardation and fetal death at 100-150 mg/kg/day, without signs of maternal toxicity. Investigations continue into the mechanism for the developmental toxicity of cysteamine.     

Fertilization and early embryonic development in poultry

There are two major controllers of development in the early stages of bird embryos. These are: 1) gravity, probably acting through the distribution of yolk and its components, which lays down the initial plans for polarity that are later established firmly through the genes; and 2) the primitive streak, which controls the orderly ingression of the cells and imposes a pattern on the developing tissues.     

In utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-rho-dioxin: effects on development of the male and female reproductive system of the mouse

To evaluate effects of in utero and lactational 2,3,7,8-tetrachlorodibenzo-rho-dioxin (TCDD) exposure on male and female reproductive system development of the mouse, the offspring of pregnant ICR mice administered 0, 15, 30, or 60 microg TCDD/kg on Gestation Day (GD) 14 were examined at the postweanling, pubertal, young adult, and adult stages of development. Dam and offspring body weights and prenatal and postnatal mortality were unaffected by TCDD exposure. The most sensitive endpoints in male offspring were decreased ventral prostate, coagulating gland, and thymus weights, accelerated eye opening, and hydronephrosis. Decreases in pituitary gland weight and epididymal sperm numbers were also found in TCDD-exposed male offspring. Testis, epididymis, and dorsolateral prostate weights, anogenital distance, latencies to testis descent and to preputial separation, and serum testosterone concentrations were unaffected. At the highest maternal TCDD dose uterus weights were decreased in female offspring evaluated during estrus and diestrus. No morphologic changes in the external genitalia of female offspring were found, nor were there alterations in ovary or pituitary gland weights. Cross-species comparisons showed that the mouse was not as sensitive to TCDD-induced developmental reproductive toxicity as the rat and hamster. Many endpoints affected by TCDD in rat and hamster offspring were either not affected or were less sensitive in mouse offspring. Endpoints of androgenic status were not affected in the mouse, decreases in accessory sex organ weights were restricted to fewer organs in the mouse, and decreases in daily sperm production were not found in the mouse. The only developmental reproductive endpoint observed in all three species was a reduction in epididymal sperm numbers.     

Sex determination and female reproductive development in the genus Schistosoma: a review

Telomerase, a ribonucleoprotein enzyme, is expected to be a new marker for cancer diagnosis. TRAP (the telomeric-repeat amplification protocol) developed by Kim et al. is a sensitive method to detect telomerase activity. Telomerase activity is detected by TRAP in most malignant cells in vivo and in vitro, but it is not found, or found only in very low amounts, in normal somatic cells and tissues. TRAP and its modified protocols are, however, not always suitable for measuring the activity of a large number of clinical samples to diagnose cancer, because they generally require a time-consuming detection step such as gel electrophoresis with radioactive materials. To improve the procedure for mass diagnosis, we applied a hybridization protection assay (HPA) to replace the detection step. HPA, which employs an acridinium-ester-labelled probe, is radioactivity-free, easy to handle without electrophoresis, quick, and applicable to a quantitative format. In this work we have established and demonstrated the advantages of TRAP/HPA. The telomerase activity of various primary and established cells, differentiating cancer cells, and normal and tumour colorectal and liver tissues was quantitatively analysed by TRAP/HPA. The results indicate that HPA combined with TRAP is a rapid and simple method, easy to handle and quantify, for the clinical diagnosis of cancer.     

The molecular mechanisms of oocyte maturation and early embryonic development are unveiling new insights into reproductive medicine

The purpose of the present review is to outline the current understanding on the molecular mechanisms governing various stages of oocyte maturation, transition from maternal to embryonic control and the initial steps of pre-embryo development. The cytoplasmic and nuclear maturation of the oocyte during pre-ovulatory development can be viewed as separate entities. Cytoplasmic maturation and the acquisition of stores of RNA and protein dominates oocyte development between the premordial and pre-ovulatory stages of development. Initiation of nuclear maturation is marked by the breakdown of the nuclear envelope, or germinal vesicle and is triggered by the midcycle luteinizing hormone peak. In vitro, this is associated with a decrease in the intracellular concentrations of cAMP. This and several subsequent steps of meiosis are controlled by the M-phase promoting factor (MPF). While the constituents of MPF, p34cdc2 kinase and B-type cyclin, are also present in mitotically dividing cells, in meiotically dividing oocytes the regulation of MPF activity differs. An oocyte-specific protein kinase, c-mos, plays an important role in up-regulating the activity of MPF at various stages of final oocyte maturation. Several lines of evidence suggest that the proper function of the c-mos-MPF system is associated with important features of the last stages of oocyte maturation such as the resumption of meiotic maturation, inhibition of DNA replication between meiosis I and II, and the maintenance of the oocyte at metaphase II arrest until it is fertilized. Eventually the destruction of c-mos and active MPF following fertilization allows the initiation of mitotic cell division in the pre-embryo. The very first cell divisions of the human pre-embryo are still under the control of maternally inherited mRNA and protein. Several lines of evidence suggest that in humans, zygotic gene expression is initiated between the 4- and 8-cell stages, after which the pre-embryo begins to utilize its own genes. Some of the first genes to be expressed in the human pre-embryo encode proteins that are associated with cell division, extracellular growth modulatory signals as well as factors associated with implantation. We acknowledge that most of the data presented comes from species other than human, therefore at present the full biological role of the proposed regulatory pathways and control mechanisms for human biology remains speculative.     

Bacterial infection and endotoxin in female reproductive tract in rats: correlation with the developmental status of preimplantation embryos

During mammalian preimplantation development, a substantial numbers of embryos are believed to be lost for reasons that are unclear. Using female rats, we investigated whether the developmental status of embryos is influenced by bacterial infection and endotoxin in the reproductive tract. From the vagina of cycling rats (n = 11), 21 bacterial isolates were identified; they were Streptococcus faecalis (S. faecalis; 38%), Escherichia coli (E. coli; 19%), Acinetobactor calcoaceticus (A. calcoaceticus; 14%), and coagulase negative staphylococcus (14%), Micrococcus sp. (5%), Bacillus subtilis (B. subtilis; 5%) and Proteus vulgaris (P. vulgaris; 5%). From the vagina of day 4 pregnant rats (n = 12), 26 isolates were identified; they were S. faecalis (23%), A. calcoaceticus (23%), E. coli (15%), Micrococcus sp. (15%), B. subtilis (8%), P. vulgaris (4%), Staphylococcus aureus (4%), beta-hemolytic streptococcus (4%) and Pseudomonas aeruginosa (4%). Gram negative bacteria found in the vagina of cycling and day 4 pregnant rats were 38% and 46%, respectively. In both, bacterial load was 10(3)-10(5) colony forming units and there was no association with the abnormality of the recovered embryos. However, in two day 4 pregnant animals, pathogenic bacteria (Staphylococcus aureus and beta-hemolytic streptococcus) were isolated and embryos recovered from them were degenerated and deformed. The vagina of day 9 pregnant animals (n = 7) were, however, sterile. Consistently, in all animals, the upper reproductive tract (uterus and oviduct) was devoid of any bacteria and no anaerobic bacteria were isolated from any part of the tract. The levels of endotoxin in the vagina of cycling and day 4 pregnant rats were 1.35 +/- 0.1 and 1.17 +/- 0.1 endotoxin units (EU), respectively. It was undetectable in the oviduct and uterus of all animals (n = 5) except one which showed high levels of endotoxin in uterus (4.5 EU) and oviduct (2.2 EU) and the animal also produced degenerated and deformed embryos. These results indicate that common bacterial flora of vagina may not affect embryo development and the presence of pathogenic bacteria in the vagina and/or endotoxin in reproductive tract could be detrimental to viability of gametes and preimplantation embryos in rats.     

The Drosophila maternal effect locus deadhead encodes a thioredoxin homolog required for female meiosis and early embryonic development

This study describes the identification, function and molecular characterization of deadhead, a Drosophila thioredoxin homolog. Although in vitro studies have shown that thioredoxin can post-translationally regulate the activity of many different proteins, we find that this homolog is not essential for viability. The phenotypic analysis of two different mutations which eliminate function suggests that dhd is essential for female meiosis. The majority of eggs laid by females homozygous for null mutations are fertilized but fail to complete meiosis. A small number of escaper embryos initiate development and display a range of phenotypes suggesting functions in both preblastoderm mitosis and head development. Our analysis of deadhead's RNA expression pattern is consistent with its maternal effect function: the RNA is predominately expressed in the nurse cells of the ovary, is maternally deposited into the egg, but does not appear to be zygotically expressed during embryogenesis. Thus both our genetic and molecular data are consistent with a function during meiosis and preblastoderm mitosis. Whether the head defect indicates an additional function or is an indirect consequence of earlier defects remains to be determined.     

Vanadium: a review of the reproductive and developmental toxicity

With the increasing numbers of older adults in our population, nurses are reexamining all aspects of nursing care in order to best meet the needs of these individuals. Normal age changes, the impact of decades of environmental challenges, successful adaptations, acute illnesses, trauma and chronic illnesses combine to create a challenge for accurate and effective assessment of elderly patients. The nurse finds her assessment skills challenged with increasing frequency by the elderly patient who is also acutely confused and experiencing discomfort. The purpose of this study was to explore the clinical utility, validity and reliability of four different approaches to nursing assessment of discomfort with this particularly vulnerable group of elders.     

Study of the effects of beta-myrcene on rat fertility and general reproductive performance

beta-Myrcene (MYR) is a monoterpene found in the oils of a variety of aromatic plants including lemongrass, verbena, hop, bay, and others. MYR and essential oils containing this terpenoid compound are used in cosmetics, household products, and as flavoring food additives. This study was undertaken on investigate the effects of MYR on fertility and general reproductive performance in the rat. MYR (0, 100, 300 and 500 mg/kg) in peanut oil was given by gavage to male Wistar rats (15 per dose group) for 91 days prior to mating and during the mating period, as well as to females (45 per dose group) continuously for 21 days before mating, during mating and pregnancy, and throughout the period of lactation up to postnatal day 21. On day 21 of pregnancy one-third of the females of each group were submitted to cesarean section. Resorption, implantation, as well as dead and live fetuses were counted. All fetuses were examined for external malformations, weighed, and cleared and stained with Alizarin Red S for skeleton evaluation. The remaining dams were allowed to give birth to their offspring. The progeny was examined at birth and subsequently up to postnatal day 21. Mortality, weight gain and physical signs of postnatal development were evaluated. Except for an increase in liver and kidney weights, no other sign of toxicity was noted in male and female rats exposed to MYR. MYR did not affect the mating index (proportion of females impregnated by males) or the pregnancy index (ratio of pregnant to sperm-positive females). No sign of maternal toxicity and no increase in externally visible malformations were observed at any dose level. Only at the highest dose tested (500 mg/kg) did MYR induce an increase in the resorption rate and a higher frequency of fetal skeleton anomalies. No adverse effect of MYR on postnatal weight gain was noted but days of appearance of primary coat, incisor eruption and eye opening were slightly delayed in the exposed offspring. On the basis of the data presented in this paper the no-observed-adverse-effect level (NOAEL) for toxic effects on fertility and general reproductive performance can be set at 300 mg of beta-myrcene/kg body weight by the oral route.     

Precursors of taurine in female genital tract: effects on developmental capacity of bovine embryo produced in vitro

The Müllerian duct (MD; ductus paramesonephricus) develops independent of the coelomic epithelium above the mesonephros. This part of the duct gives rise to the infundibulum with its fimbriated ostium abdominale. The part of the duct which lies along the mesonephros as far as its caudal pole makes a contribution to the ampulla and less often the isthmus. In the area of the mesonephros the MD fuses with the Wolffian duct (WD; ductus mesonephricus). The WD gives rise to the ampulla and the isthmus. Below the caudal pole of the mesonephros, as well as beyond the attachment point of the inguinal ligament of the mesonephros, the later round ligament of the uterus, the MD develops as an outgrowth of the WD and no longer as an independent structure. The MRK syndrome is, in its formal genesis, a non-fusion of the MD with the WD. This explains the fact that in a classic case of MRK syndrome, the Fallopian tube with a very small part of the cornu uteri extends only as far as the connection with the round ligament of the uterus. Different possibilities for the origin of MRK syndrome are discussed. It is suggested that the cause of the development of MRK syndrome could be a deficiency of gestagen and/or oestrogen receptors. This would also explain the various forms of the rudimentary vagina.     

The effects of oophorectomy and female sex steroids on glucose kinetics in the rat

In the present study, we have analyzed the appearance and maturation of gamma/delta T cells, recognized with a new mAb V65, in the central and peripheral lymphoid organs of fetal, neonatal, and adult Wistar rats. Cytofluorometrical analysis demonstrated the first V65+ gamma/delta T cells in the thymus of 16-17-day embryonic rats, although by immunohistology, they were identified only in 19-day rat embryos in both the cortico-medullary border and thymic medulla. Phenotypically, gamma/delta thymocytes from fetal and neonatal thymus expressed CD3, CD2, and CD5, but only 60-80% were CD8+ and approximately 40-50% expressed the alpha chain (p55) of the IL-2R. In the periphery, the immunohistological study identified for the first time gamma/delta T cells in the splenic white pulp and the gut of 21-day fetal rats, where they occurred within the epithelium as well as in the lamina propria. After birth, gamma/delta lymphocytes appeared in the skin, where they were present as dendritic epidermal T cells in increasing numbers during postnatal life. Whereas these gamma/delta T cells formed the predominant T-cell population in the rat skin, gamma/delta T cells in peripheral lymphoid organs, BALT, or the gut only represented a minor T-cell population. These results are discussed in comparison to gamma/delta T cells of other vertebrate species.     

Carcass traits and reproductive development at the onset of lay in two lines of female turkeys

A study was conducted comparing ovary and oviduct development following photostimulation in two lines of turkey breeder stocks (female line and male line). Birds were euthanatized for assessment of reproductive organ morphology at 3-d intervals following photostimulation (203 d of age) to 245 d and on the day following their first oviposition. The age at first oviposition was similar for both lines. Male line birds were 3 to 4 kg heavier than female line birds throughout the study, but had lower abdominal fat pad weights when expressed as a percentage of BW. Female line birds had significantly more total carcass lipid as a percentage of BW than male line birds (24.76 vs 22.79%, respectively). Male line birds had significantly more large ovarian follicles with a greater proportion in a triple or greater hierarchical arrangement at first egg. To determine the incidence of unreconciled ovulations (presumed to be internally ovulated follicles and defined as ovulations occurring prior to first oviposition), postovulatory follicles on the ovary were reconciled with observed ovipositions and the developing eggs that were in the oviduct at the time of study. On average, male line hens had 3.0 unreconciled postovulatory follicles at first egg, whereas the female line hens had 1.6. The incidence of birds with physical remnants of internal ovulation was correlated (r = 0.44) to the number of unreconciled ovulations. The developing oviduct of the female line birds reached its mature weight (84.8 g) 3 d earlier than the ovary did. The developing ovary and oviduct of the male line hens reached their mature weights on the same day. The development of the male line oviduct is seemingly accelerated relative to that of the ovary, resulting in lost ovulations early in lay.     

Genotypically dependent effects of cyromazine on reproduction and offspring development in the Australian Lucilia cuprina (Diptera: Calliphoridae)

Various factors may influence bioavailability and blood concentrations of cyclosporine, a problem that may be compounded by diseases such as cystic fibrosis in which impaired absorption through the gastrointestinal tract is common. Neoral, a microemulsion formulation of cyclosporine, has improved bioavailability and more stable blood concentrations than earlier formulations. We conducted a prospective, open, crossover study to examine whether these findings held true in 12 clinically stable patients with cystic fibrosis who had undergone lung transplantation at least 6 months earlier. In the first arm, patients continued their usual dosage of cyclosporine twice/day. In the second arm they received Neoral for at least 1 week before having blood studies. For each arm whole blood trough concentrations were drawn for 7-10 successive days, together with a pharmacokinetic study with concentrations drawn at times zero, 1, 2, 3, 4, 6, 12, and 24 hours. Variance was assessed from morning concentrations. Area under the curve from zero to 12 hours (AUC12), maximum concentration (Cmax), and time to Cmax (Tmax) were calculated for each arm. Eleven subjects completed the protocol. The daily variance for Neoral was significantly less than for cyclosporine (p=0.04). The AUC12 for Neoral and cyclosporine were 4164+/-1467 and 5318+/-1670 microg x L/hour (p=0.09), respectively. Respective Cmax were 613+/-242 and 931 +/-458 microg/L (p=0.08) and relative Cmax and AUC12 were 1.91 and 1.47 (p<0.05). Thus Neoral had a superior pharmacokinetic profile and less day-to-day variability in patients with cystic fibrosis who had undergone lung transplantation.     

Differential effects of perinatal hypoxic risk on early developmental outcome: A twin study.

The goal of this twin study was to explore the effects of perinatal neurobiological risk on 2 dimensions of early developmental outcome: mental and motor. The hypothesis was that the performance of the twin considered to be at higher risk for hypoxic insult would fall short of that exhibited by the lower risk co-twin. Twin discordance was established on 2 indirect indices of perinatal hypoxic risk: the Apgar score and the degree of need for neonatal respiratory oxygen support. The early outcome measures, the Bayley Scales of Infant Development (BSID), mental (MDI) and psychomotor (PDI) components, were obtained for 76 infants. Fifty-six infants were from 28 pairs of twins who were determined to be discordant, and 20 infants from 10 additional pairs who were found to be nondiscordant, on the risk indices. Although the average differences between the discordant co-twins in Apgar scores and in need for oxygen supplementation were small, the twins who were at higher risk for hypoxic insult had a significantly lower MDI compared to their lower risk co-twins. This within-pair effect was somewhat greater for premature, same-sex twins. No intrapair differences associated with risk level were found on the PDI.… (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Domestication and early experience effects on escape conditioning in the Norway rat.

Compared 16 male and 16 female wild and domestic Norway rats reared in both field and laboratory environments in the acquisition and inhibition of a conditioned escape response. Domestic Ss were conditioned in significantly fewer trials. Strain performance was not differentially inhibited by air blasting during postacquisition test sessions. Rearing environment had no effect on either acquisition or inhibition of the conditioned response. (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Buying safety: the economics of reproductive risk and abortion in Egypt

This article examines the economics of abortion safety in Egypt. Under Egyptian law induced abortion is restricted to cases in which two physicians certify that the pregnancy presents a danger to the health or life of the mother. Despite this legal restriction, the available data indicate that abortion is quite widely practiced. Multifaceted strands of legal, religious, economic, and health care policy influence both discourse about and access to abortion in Egypt. Interviews with 18 Egyptian women who sought to terminate their pregnancies revealed a wide range of abortion methods that varied in both safety and cost. Three levels of safety were identified: (1) indigenous (wasfa baladi) methods were potentially the least safe; (2) biomedical abortions at clandestine clinics appeared safer than indigenous methods, but were not without risk: and (3) biomedical abortions administered by private gynecologists, were the most safe. Safety is expensive. Wealthy women can literally buy safety, while poor women's lack of financial resources put their lives at great risk.     

Paternal exposures: impact on reproductive and developmental outcome. An overview

Corticosteroid 11 beta-hydroxylation is catalysed by 11 beta-hydroxylase and aldosterone synthase. Using plasma steroid ratios, the level of this process in patients with glucocorticoid-suppressible hyperaldosteronism (GSH) was compared with that in unaffected control subjects and in patients with Conn's syndrome. Based on both 11-deoxycortisol:cortisol (S:F) and 11-deoxycorticosterone:corticosterone (DOC:B) ratios, patients with GSH showed impaired resting 11 beta-hydroxylase activity. In GSH, but not in the other groups, the S:F ratio was significantly correlated with basal plasma aldosterone concentration. ACTH infusion increased the S:F ratio in all these patient groups, suggesting a common partial deficiency. The results also indicate that 11 beta-hydroxylation may be rate-limiting in normal subjects. In control subjects and patients with Conn's syndrome, the DOC:B ratio was not affected by ACTH. However, in GSH patients, this ratio fell markedly, indicating an increased efficiency of 11 beta-hydroxylation of DOC (but not S). This may be due to the activation by ACTH of the zona fasciculata chimaeric aldosterone synthase characteristic of this disease. Plasma aldosterone, corticosterone and DOC concentrations, appeared to be more sensitive to ACTH in GSH than the other groups. The defect in 11 beta-hydroxylation in GSH accounts for the increased levels of DOC reported in the condition, and may contribute to the phenotypic variability.