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1.
Alcohol is a potent neuroteratogen that can trigger neuronal death in the developing brain. However, the mechanism underlying this alcohol‐induced neuronal death is not fully understood. Utilizing primary cultures of cerebellar granule neurons (CGN), we tested the hypothesis that the alcohol‐induced increase in intracellular calcium [Ca2+]i causes the death of CGN. Alcohol induced a dose‐dependent (200–800 mg/dL) neuronal death within 24 h. Ratiometric Ca2+ imaging with Fura‐2 revealed that alcohol causes a rapid (1–2 min), dose‐dependent increase in [Ca2+]i, which persisted for the duration of the experiment (5 or 7 min). The alcohol‐induced increase in [Ca2+]i was observed in Ca2+‐free media, suggesting intracellular Ca2+ release. Pre‐treatment of CGN cultures with an inhibitor (2‐APB) of the inositol‐triphosphate receptor (IP3R), which regulates Ca2+ release from the endoplasmic reticulum (ER), blocked both the alcohol‐induced rise in [Ca2+]i and the neuronal death caused by alcohol. Similarly, pre‐treatment with BAPTA/AM, a Ca2+‐chelator, also inhibited the alcohol‐induced surge in [Ca2+]i and prevented neuronal death. In conclusion, alcohol disrupts [Ca2+]i homeostasis in CGN by releasing Ca2+ from intracellular stores, resulting in a sustained increase in [Ca2+]i. This sustained increase in [Ca2+]i may be a key determinant in the mechanism underlying alcohol‐induced neuronal death.  相似文献   

2.
Traditional techniques for quantification of murine fetal skeletal development (gross measurements, clear‐staining) are severely limited by specimen processing, soft tissue presence, diffuse staining, and unclear landmarks between which to make measurements. Nondestructive microcomputed tomography (micro‐CT) imaging is a versatile, well‐documented tool traditionally used to generate high‐resolution 3‐D images and quantify microarchitectural parameters of trabecular bone. Although previously described as a tool for phenotyping fetal murine specimens, micro‐CT has not previously been used to directly measure individual fetal skeletal structures. Imaging murine fetal skeletons using micro‐CT enables the researcher to nondestructively quantify fetal skeletal development parameters including limb length, total bone volume, and average bone mineral density, as well as identify skeletal malformations. Micro‐CT measurement of fetal limb lengths correlates well with traditional clear‐staining methods (83.98% agreement), decreases variability in measurements (average standard errors: 6.28% for micro‐CT and 10.82% for clear‐staining), decreases data acquisition time by eliminating the need for tissue processing, and preserves the intact fixed fetus for further analysis. Use of the rigorous micro‐CT technique to generate 3‐D images for digital measurement enables isolation of skeletal structures based on degree of mineralization (local radiodensity), eliminating the complications of blurred stain boundaries and soft tissue inclusion that accompany clear‐staining and gross measurement techniques. Microcomputed tomography provides a facile, accurate, and nondestructive method for determining the developmental state of the fetal skeleton using not only limb lengths and identification of malformations, but total skeletal bone volume and average skeletal mineral density as well. Birth Defects Res (Part B) 2008. © 2008 Wiley‐Liss, Inc.  相似文献   

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Embryo‐fetal development (EFD) studies, typically in pregnant rats and rabbits, are conducted prior to enrolling females of reproductive age in clinical trials. Common rabbit strains used are the New Zealand White (NZW) and Dutch Belted (DB). As fetal abnormalities can occur in all groups, including controls, Historical Control Data (HCD) is compiled using data from control groups of EFD studies, and is used along with each study's concurrent control group to help determine whether fetal abnormalities are caused by the test article or are part of background incidences. A probability analysis was conducted on 2014 HCD collected at Charles River Inc., Horsham PA on Covance NZW, Covance DB, and Charles River (CR) NZW rabbits. The analysis was designed to determine the probability of 2 or 3 out of a group of 22 does aborting their litter or of having a fetal abnormality by chance. Results demonstrate that pregnancy parameters and fetal observations differ not only between strains, but between sources of rabbits of the same strain. As a result the probability of these observations occurring by chance in two or three litters was drastically different. Although no one single strain is perfect, this analysis highlights the need to appreciate the inherent differences in pregnancy and fetal abnormalities between strains, and points out that an apparent isolated increased incidence of an observation in one strain will not necessarily be test‐article related in another strain. A robust HCD is critical for interpretation of EFD rabbit studies, regardless of the rabbit strain used  相似文献   

5.
Throughout the second and third trimesters, the human placenta (and the placenta in other anthropoid primates) produces substantial quantities of corticotropin-releasing hormone (placental CRH), most of which is secreted into the maternal bloodstream. During pregnancy, CRH concentrations rise over 1000-fold. The advantages that led selection to favour placental CRH production and secretion are not yet fully understood. Placental CRH stimulates the production of maternal adrenocorticotropin hormone (ACTH) and cortisol, leading to substantial increases in maternal serum cortisol levels during the third trimester. These effects are puzzling in light of widespread theory that cortisol has harmful effects on the fetus. The maternal hypothalamic-pituitary-adrenal (HPA) axis becomes less sensitive to cortisol during pregnancy, purportedly to protect the fetus from cortisol exposure. Researchers, then, have often looked for beneficial effects of placental CRH that involve receptors outside the HPA system, such as the uterine myometrium (e.g. the placental clock hypothesis). An alternative view is proposed here: the beneficial effect of placental CRH to the fetus lies in the fact that it does stimulate the production of cortisol, which, in turn, leads to greater concentrations of glucose in the maternal bloodstream available for fetal consumption. In this view, maternal HPA insensitivity to placental CRH likely reflects counter-adaptation, as the optimal rate of cortisol production for the fetus exceeds that for the mother. Evidence pertaining to this proposal is reviewed.  相似文献   

6.
Bordetella pertussis, B. parapertussis, and B. bronchiseptica cause respiratory infections in mammals, including humans, and are generally cultivated on Bordet‐Gengou (BG) agar plates in laboratories. The medium requires animal blood as a supplement for better bacterial growth. However, using blood is problematic, as its constant supply is occasionally difficult because of the limited shelf‐life. This study proposes modified BG agar plates supplemented with bovine serum albumin and fetal bovine serum as a simple and convenient medium that confers sufficient growth of bordetellae.  相似文献   

7.
The pharmacotoxicology impacts of dietary supplements taken at the time of pregnancy have remained alarming since women are the frequent herbal medicine users in many countries as a complement to the conventional pregnancy management. The use of herbal medicines and diet supplements in expectant mothers linked closely to the health of the childbearing mothers and the fetuses where the lack of developmental safety data imposes a challenge to make the right choices. Here, we describe the potential adverse effects of UP446, a standardized bioflavonoid composition from the roots of Scutellaria baicalensis and the heartwoods of Acacia catechu, on embryo‐fetal development following maternal exposure during the critical period of major organogenesis in rabbits and rats. Pregnant dams were treated orally with UP446 at doses of 250, 500, and 1000 mg/kg/day during gestation. The number of resorptions, implantations, litter size, body weights, and skeletal development was evaluated. Maternal food intake and body, tissue, and placenta weight were also assessed. There were no statistically significant differences in implantation, congenital malformation, embryo‐fetal mortalities, and fetuses sex ratios in all dosing groups of both species. Therefore, the no observed adverse effect level of UP446 was considered to be greater than 1000 mg/kg in both the maternal and fetus in both species  相似文献   

8.
Prenatal ethanol exposure (PEE) can lead to structural and functional abnormalities in fetal brain. Although neural developmental deficits due to PEE have been recognized, the immediate effects of PEE on fetal brain vasculature and hemodynamics remain poorly understood. One of the major obstacles that preclude the rapid advancement of studies on fetal vascular dynamics is the limitation of the imaging techniques. Thus, a technique for noninvasive in‐vivo imaging of fetal vasculature and hemodynamics is desirable. In this study, we explored the dynamic changes of the vessel dimeter, density and oxygen saturation in fetal brain after acute maternal ethanol exposure in the second‐trimester equivalent murine model using a real‐time photoacoustic tomography system we developed for imaging embryo of small animals. The results indicate a significant decrease in fetal brain vessel diameter, perfusion and oxygen saturation. This work demonstrated that PAT can provide high‐resolution noninvasive imaging ability to monitor fetal vascular dynamics.  相似文献   

9.
Human chorion‐derived stem cells (hCDSC) were previously shown to demonstrate multipotent properties with promising angiogenic characteristics in monolayer‐cell culture system. In our study, we investigated the angiogenic capability of hCDSC in 3‐dimensional (3D) in vitro and in vivo angiogenic models for the purpose of future application in the treatment of ischaemic diseases. Human CDSC were evaluated for angiogenic and endogenic genes expressions by quantitative PCR. Growth factors secretions were quantified using ELISA. In vitro and in vivo vascular formations were evaluated by histological analysis and confocal microscopic imaging. PECAM‐1+ and vWF+ vascular‐like structures were observed in both in vitro and in vivo angiogenesis models. High secretions of VEGF and bFGF by hCDSC with increased expressions of angiogenic and endogenic genes suggested the possible angiogenic promoting mechanisms by hCDSC. The cooperation of hCDSC with HUVECS to generate vessel‐like structures in our systems is an indication that there will be positive interactions of hCDSC with existing endothelial cells when injected into ischaemic tissues. Hence, hCDSC is suggested as the novel approach in the future treatment of ischaemic diseases.  相似文献   

10.
For wild belugas (Delphinapterus leucas), gestation length estimates based on fetal size have produced extreme ranges. Ex situ populations thereby provide unique opportunities to define this important life history event. Accordingly, research with ultrasound was conducted on six beluga whales over 11 gestations with known conception dates to serially measure fetal changes in biparietal diameter (BP), thoracic diameter (TD), thoracic circumference (TC), and total length (TL). Incremental polynomial regression analyses were performed on each fetal measurement to develop predictive models for determining age based on fetal size and days from parturition. Gestation length (n = 11) was a mean 467 ± 5.4 d with male calves (478 ± 8.6 d) experiencing a longer gestation (P = 0.04) than females (457 ± 3.9 d). Age at TL was best described using a 2nd order polynomial model, while linear relationships existed for BPD, TD, and TC. Accuracy was improved for predicting age (P = 0.001) or days prior to parturition (P = 0.038) using data from the first vs. the second half of gestation. The results provide accurate models for aging beluga fetuses based on size in both in situ and ex situ populations.  相似文献   

11.
This article focuses on maternal‐fetal surgery (MFS) and on the concept of clinical equipoise that is a widely accepted requirement for conducting randomized controlled trials (RCT). There are at least three reasons why equipoise is unsuitable for MFS. First, the concept is based on a misconception about the nature of clinical research and the status of research subjects. Second, given that it is not clear who the research subject/s in MFS is/are, if clinical equipoise is to be used as a criterion to test the ethical appropriateness of RCT, its meaning should be unambiguous. Third, because of the multidisciplinary character of MFS, it is not clear who should be in equipoise. As a result, we lack an adequate criterion for the ethical review of MFS protocols. In our account, which is based on Chervenak and McCullough's seminal work in the field of obstetric ethics, equipoise is abandoned. and RCT involving MFS can be ethically initiated when a multidisciplinary ethics review board (ERB), having an evidence‐based assessment of the risks involved, is convinced that the value of answering the research hypothesis, for the sake of the health interests of future pregnant women carrying fetuses with certain congenital birth defects, justifies the actual risks research participants might suffer within a set limit of low/manageable.  相似文献   

12.
Compilation of marine mammal demographic data is central to management efforts. However, marine mammal length‐at‐age growth curves demonstrate limitations. Physiological growth parameters of terrestrial mammals are typically estimated using curvilinear models fit to size‐at‐age data along a time series from conception to senescence. The difficulty of collecting and aging prenatal cetaceans is addressed here, and growth parameters of common bottlenose dolphins (Tursiops truncatus) along coastal Texas were estimated using length‐at‐age information from a broader scope of age classes, including late‐term fetuses. A Gompertz growth curve fit to pre‐ and postnatal data underestimated size parameters, but demonstrated similar growth rate constants (k) to an exclusively postnatal model. However, when growth parameters were broken out, the absolute growth rate (G) and rate of growth decay (g) decreased (0.44 from 0.27 and 0.55 from 0.39, respectively), which underscores the importance of reporting k in its expanded form (G/g). Although the Gompertz fits most age classes well, it cannot explain growth in all age classes. We argue that a novel sigmoidal model would be more useful for inference.  相似文献   

13.
Intestinal mucins are very high molecular weight glycoproteins secreted by goblet cells lining the crypt and the surface of the colonic mucosa. Profound alterations of mucin O-glycans are observed in diseases such as cancer and inflammation, modifying the function of the cell and its antigenic and adhesive properties. Based on immunohistochemical studies, certain cancer- and inflammation- associated glycans have been defined as oncofetal antigens. However, little or no chemical analysis has allowed the structural elucidation of O-glycans expressed on human fetal mucins. In this paper, mucins were isolated from different regions of the normal human intestine (ileum, right, transverse and left colon) of eight fetuses with A, B or O blood group. After alkaline borohydride treatment, the released oligosaccharides were investigated by nanoESI Q-TOF MS/MS (electrospray ionization quadrupole time-of-flight tandem mass spectrometry). More than 117 different glycans were identified, mainly based on core 2 structures. Some core 1, 3 and 4 oligosaccharides were also found. Most of the structures were acidic with NeuAc residues mainly α2–6 linked to the N-acetylgalactosaminitol and sulphate residues 3-linked to galactose or 6-linked to GlcNAc. In contrast to adult human intestinal mucins, Sda/Cad determinants were not expressed on fetal mucin O-glycans and the presence of an acidic gradient along the intestinal tract was not observed. Similar patterns of glycosylation were found in each part of the intestine and the level of expression of the major oligosaccharides was in the same order of magnitude. This study could help determining new oncofetal antigens, which can be exploited for the diagnosis or the treatment of intestinal diseases.  相似文献   

14.
Cell‐based therapy using stem cells has emerged as one of the pro‐angiogenic methods to enhance blood vessel growth and sprouting in ischaemic conditions. This study investigated the endogenous and induced angiogenic characteristics of hCDSC (human chorion‐derived stem cell) using QPCR (quantitative PCR) method, immunocytochemistry and fibrin‐matrigel migration assay. The results showed that cultured hCDSC endogenously expressed angiogenic–endogenic‐associated genes (VEGF, bFGF, PGF, HGF, Ang‐1, PECAM‐1, eNOS, Ve‐cad, CD34, VEGFR‐2 and vWF), with significant increase in mRNA levels of PGF, HGF, Ang‐1, eNOS, VEGFR‐2 and vWF following induction by bFGF (basic fibroblast growth factor) and VEGF (vascular endothelial growth factor). These enhanced angiogenic properties suggest that induced hCDSC provides a stronger angiogenic effect for the treatment of ischaemia. After angiogenic induction, hCDSC showed no reduction in the expression of the stemness genes, but had significantly higher levels of mRNA of Oct‐4, Nanog (3), FZD9, ABCG‐2 and BST‐1. The induced cells were positive for PECAM‐1 (platelet/endothelial cell adhesion molecule 1) and vWF (von Willebrand factor) with immunocytochemistry staining. hCDSC also showed endothelial migration behaviour when cultured in fibrin‐matrigel construct and were capable of forming vessels in vivo after implanting into nude mice. These data suggest that hCDSC could be the cells of choice in the cell‐based therapy for pro‐angiogenic purpose.  相似文献   

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为探讨适合水牛胎儿成纤维细胞(BFF)的体外培养体系,采用常规组织块法和胰蛋白酶消化法原代培养BFF均获得了较多的成纤维细胞,但后者所得细胞的活力不如前者高,且死细胞也较多;传代或冻存成纤维细胞时用4℃预冷的胰蛋白酶室温下消化所得的细胞比37℃热消化的细胞更圆、更有光泽;跟踪32代的细胞冷冻复苏率均达70%~80%;染色体分析结果显示,二倍体细胞所占比例始终保持在80%~90%之间,各代细胞(5th、10th、15th)之间差异不显著(P>0.05).结果 表明,组织块法原代培养、4℃预冷胰蛋白酶室温消化传代细胞的培养体系比较适合水牛胎儿成纤维细胞的培养.  相似文献   

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The polyproteins of coronaviruses are cleaved by viral proteases into at least 15 nonstructural proteins (Nsps). Consisting of five domains, Nsp3 is the largest of these (180–210 kDa). Among these domains, the so‐called X‐domain is believed to act as ADP‐ribose‐1″‐phosphate phosphatase or to bind poly(ADP‐ribose). However, here we show that the X‐domain of Infectious Bronchitis Virus (strain Beaudette), a Group‐3 coronavirus, fails to bind ADP‐ribose. This is explained on the basis of the crystal structure of the protein, determined at two different pH values. For comparison, we also describe the crystal structure of the homologous X‐domain from Human Coronavirus 229E, a Group‐1 coronavirus, which does bind ADP‐ribose.  相似文献   

19.
The present study deals with whether lipopolysaccharide (LPS)-induced intra-uterine fetal death (IUFD) is related to LPS-susceptibility of either mother or fetus and how LPS or LPS-induced TNF causes IUFD. LPS-susceptible C3H/HeN or -hypo-susceptible C3H/HeJ pregnant mice and the mice mated reciprocally with these mice were used on days 14 to 16 of gestation for experiments. All of fetuses in pregnant C3H/HeN mice mated with either C3H/HeN males [HeN(HeN)] or C3H/HeJ males [HeN(HeJ)] were killed within 24 hr when injected intravenously (i.v.) with 50 or 100 microg of LPS. On the other hand, the majority of fetuses in C3H/HeJ females mated with either C3H/HeJ males [HeJ(HeJ)] or C3H/HeN males [HeJ(HeN)] survived when injected i.v. with even 400 microg of LPS. These findings indicate that LPS-induced IUFD depends on the maternal LPS-responsiveness. LPS injected into mothers could pass through placenta to fetuses, since an injection with 125I-labeled LPS or IgG into pregnant mice resulted in considerable levels of radioactivity in fetuses as well as placenta. Cultured peritoneal macrophages derived from F1 mice of HeJ(HeN) or HeN(HeJ) mice, produced nitric oxide (NO) and tumor necrosis factor (TNF) in response to LPS, although the levels of NO and TNF were lower in comparison with those of C3H/HeN macrophage cultures, suggesting a possibility that the fetus as well as F1 cells might be responsible to LPS. LPS-induced IUFD was not blocked by treatment with anti-TNF antibody which inhibited LPS-induced TNF production in pregnant females, although an injection of recombinant TNFalpha instead of LPS could induce IUFD, suggesting that the cause of IUFD cannot be attributed to mother-derived TNF alone. The roles of LPS passed through placenta and LPS-induced mediators on IUFD were discussed.  相似文献   

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