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671.
In 192 oocyte donation cycles performed between January 1993 and July 1996, we examined the width of 'the window for embryo transfer' using standard hormonal replacement methods. All transfers were performed within 48 h of insemination. We varied the day of embryo transfer with regard to the initiation of progesterone therapy and, thus, the duration of endometrial exposure to progesterone and analysed the resulting pregnancy rates. Patients were divided into five groups (I-V) and embryo transfers were performed 2, 3, 4, 5 or 6 days following initiation of progesterone therapy. The number of pregnancies per transfer cycle achieved in groups I-V were 0 (0%), 3 (12%), 16 (40%), 29 (48.3%), and 10 (20.4%) respectively. The increased pregnancy rate in group III in comparison to group II is statistically significant (P < 0.03). Furthermore, the pregnancy rate in group IV (5 days of progesterone administration before embryo transfer) was significantly higher than in group V (6 days of progesterone administration before embryo transfer; P < 0.005). We also noted that, when embryos were transferred 4 or 5 days after initiation of progesterone therapy, the pregnancy rates were not significantly different between menopausal and cycling recipients (50% vs 43.7%). Our results indicate that the window for embryo transfer is dependent on duration of treatment with progesterone; it begins approximately 48 h after starting progesterone administration and lasts for approximately 4 days. The optimum period for transferring embryos at the 4- to 8-cell stage corresponds to cycle days 18 and 19. Transfers performed on the 17th and 20th days of the cycle can result in successful implantation, although the rates of implantation are highest when transfers are done on days 18 and 19.   相似文献   
672.
Objectives To establish a new transgenic mouse model for determining the function and role of human scavenger receptor A (SR- A) in atherosclerosis in vivo. Methods Human scavenger receptor minigene- driven mouse tie- 1 promoter was constructed and confirmed by endonuclease digestion and sequence analysis. Transgenic mice were generated via the microinjection method. PCR and Southern blot were used t o screen the positive transgenic mice. RT- PCR and immunohistochemical analysis were used to detect the level and location of human SR- AⅠ expression in transgenic mice. The activity of human SR- AⅠ was determined by morphologi c observation of aortic endothelial cells of transgenic mice under transmission electron microscopy. Results The electrophoresis assay showed the expected 4 fragments of 0. 9 kb, 1. 1 kb, 1. 2 kb and 4. 2 kb in the SmaⅠ digest and 2 fragments of 0. 8 kb and 6 . 7 kb in BglⅡ digest of plasmids pTie- 1/hSR- A. The fragment sequence of tie - 1 p romoter and human SR- A cDNA in plasmids pTie- 1/hSR- A was correct and no A TG b efore the translation initiation sites of human SR- A was found by sequence ana lysis. 561 injected and surviving embryos with the purified human SR- A minigen e were implanted into the oviducts of 19 ICR pseudopregnant mice. Among the 54 surviving pups from 13 foster mothers, 7 were identified by PCR and Sou thern blot analysis. The results of RT- PCR and immunohistochemical analysis sh owed human SR- A was specifically expressed on vascular endothelial cells of the aorta and renal artery, as well as hepatic sinusoidal endothelial cells in tran sgenic mice. Transmmion electron microscope (TEM) of aorta of transgenic mice s howed that a large number of vesicles, multivesicle bodies and swollen mitochond ria filled the plasma of endothelial cells. Conclusions A transgenic mouse model with overexpression of human SR- A in endothelial cells was successfully established. The transgene was integrated and transmitted int o the chromosome of transgenic mice. Tie- 1 promoter controlled the transgene t o express in endothelial cells in mice. Pinocytic activity of aortic endothelia l cells in transgenic mice was higher than that of C57BL/6J mice. Our studies w ill provide a new transgenic model for investigation of atherosclerosis and func tions of human SR- A.  相似文献   
673.

Background

The utility of healthcare utilization data from US emergency departments (EDs) for rapid monitoring of changes in influenza-like illness (ILI) activity was highlighted during the recent influenza A (H1N1) pandemic. Monitoring has tended to rely on detection algorithms, such as the Early Aberration Reporting System (EARS), which are limited in their ability to detect subtle changes and identify disease trends.

Objective

To evaluate a complementary approach, change point analysis (CPA), for detecting changes in the incidence of ED visits due to ILI.

Methodology and principal findings

Data collected through the Distribute project (isdsdistribute.org), which aggregates data on ED visits for ILI from over 50 syndromic surveillance systems operated by state or local public health departments were used. The performance was compared of the cumulative sum (CUSUM) CPA method in combination with EARS and the performance of three CPA methods (CUSUM, structural change model and Bayesian) in detecting change points in daily time-series data from four contiguous US states participating in the Distribute network. Simulation data were generated to assess the impact of autocorrelation inherent in these time-series data on CPA performance. The CUSUM CPA method was robust in detecting change points with respect to autocorrelation in time-series data (coverage rates at 90% when −0.2≤ρ≤0.2 and 80% when −0.5≤ρ≤0.5). During the 2008–9 season, 21 change points were detected and ILI trends increased significantly after 12 of these change points and decreased nine times. In the 2009–10 flu season, we detected 11 change points and ILI trends increased significantly after two of these change points and decreased nine times. Using CPA combined with EARS to analyze automatically daily ED-based ILI data, a significant increase was detected of 3% in ILI on April 27, 2009, followed by multiple anomalies in the ensuing days, suggesting the onset of the H1N1 pandemic in the four contiguous states.

Conclusions and significance

As a complementary approach to EARS and other aberration detection methods, the CPA method can be used as a tool to detect subtle changes in time-series data more effectively and determine the moving direction (ie, up, down, or stable) in ILI trends between change points. The combined use of EARS and CPA might greatly improve the accuracy of outbreak detection in syndromic surveillance systems.  相似文献   
674.
<正> A1zheimer氏病(AD)与肌萎缩侧索硬化症类似,以脑内特定的神经细胞簇内的细胞支架发生病理改变为其特点。一、神经原纤维缠结(neurofibrillaryangles; NFT):用浸银方法,组化染色及免疫细胞化学技术可显示在不同脑神经元核周的NFT,包括蓝斑、背缝核、前脑基底部胆硷能系统、杏仁核。海马和新皮层。NFT的主要成份是10nm的双股螺旋微丝(pairedhelical filaments; PHF),可能混有10nm的神经微丝和15nm的直微丝,PHF在微丝病理学中最具特色,是不溶性的交链聚合体,可能大部分由神经蛋白组成。另外,非  相似文献   
675.
Neonatal ovarian cysts: sonographic-pathologic correlation   总被引:4,自引:0,他引:4  
The authors reviewed the prenatal (11 infants) and postnatal (17 infants) sonograms and the clinical, surgical, and pathologic findings in 17 infants with an ovarian cyst to determine the sonographic features and natural history of neonatal ovarian cysts. An uncomplicated cyst (nontwisted, nonhemorrhagic) was completely anechoic and the cyst wall was imperceptible with sonography (five cases). A twisted or hemorrhagic cyst was cystic with a fluid-debris level, cystic with a retracting clot, septated with or without internal echoes, or solid (12 cases). These complicated cysts contained liquid and/or organized hematoma. Eleven of the 12 complicated cysts had a thin, highly echogenic wall. Cyst torsion commonly occurred in utero and could be diagnosed on prenatal sonograms by a typical sonographic appearance (eight cases). All of these infants were asymptomatic after birth. Four infants with hemorrhagic or twisted cysts were symptomatic. All cysts except one that resolved spontaneously were treated surgically, including three twisted cysts that showed no change in size over a 1-8-month interval. All of the cysts were of follicular origin.  相似文献   
676.
Magnetic resonance (MR) images in the sagittal plane display the lengths of the parahippocampal gyrus, subiculum, dentate gyrus, hippocampus, fimbria, fornix, hippocampal fissure, choroidal fissure, and temporal horn, and the anatomic relationships of these structures to the surrounding brain. Correlation of these images with anatomic specimens provides criteria for identifying these structures confidently on routine clinical MR imaging.  相似文献   
677.
Magnetic resonance (MR) imaging characteristics of 40 tumors involving the parapharyngeal space and the upper part of the neck were reviewed. These lesions could be classified as being either hypervascular (glomus tumors or metastatic kidney, thyroid, or venous hemangiomas) or hypovascular (salivary gland tumors, neurogenic tumors, lymphomas, sarcomas). Detailed analysis of the contour of the neoplasm combined with clinical findings allowed further refinement of the differential diagnosis in each category. Most lesions had an intermediate signal intensity on T1-weighted images and a fairly high signal intensity on T2-weighted images. Hypervascular tumors had a number of "channel voids" caused by high-flow vessels on T1- and T2-weighted images, and on T2-weighted images there were areas of high signal intensity, presumably due to sites of slow flow within the image plane. The hypovascular lesions were quite homogeneous, and it was therefore more difficult to differentiate among the neoplasms in this group.  相似文献   
678.
Angiographic ablation of parathyroid adenomas with ionic contrast material was performed in 24 patients with persistent hyperparathyroidism who had undergone at least one prior unsuccessful surgical resection; 23 had mediastinal adenomas. The success rate was 83% at 1 month after ablation and 71% at both 5 and 9 years. Ablation was successful in 85% of the patients in whom the catheter could be wedged into the artery feeding the adenoma. Long-term success was achieved in 89% of the patients in whom contrast enhancement persisted in the adenoma on computed tomographic scans obtained 24 hours later. Acute complications were seen only in patients with glands supplied by the inferior or superior thyroid arteries. Long-term complications were limited to permanent hypocalcemia, present in 8% of patients. Even if unsuccessful for ablation, the procedure may provide localization and does not preclude surgical resection. It is recommended for most patients with persistent hyperparathyroidism and mediastinal adenomas, especially adenomas supplied by the internal thoracic artery.  相似文献   
679.
680.
石衫碱甲(1)是从中草药干层塔中提取分离到的一种高效可逆的乙酰胆碱酯酶抑制剂,经临床试验证实对老年痴呆症有显著疗效。本文报道保持石杉碱甲分子基本骨架,失二个甲基类似物7和8的合成。β-酮酯2和丙烯醛发生Michael-Aldol反应得直立键和平伏键的羟基化合物9和10,其相应的甲磺酸酯11和12分别在丙二酸钠和醋酸中130℃回流,直立键甲磺酸酯11发生消去反应得需要的环内双键中间体13,而平伏键甲磺酸酯12则发生SN2取代反应得直立键醋酸酯14。基于全合成路线,合成了失二碳石杉碱甲类似物7和8,其乙酰胆碱酯酶抑制活性均低于天然石杉碱甲。  相似文献   
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