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排序方式: 共有934条查询结果,搜索用时 15 毫秒
1.
Immune responses induced by two dose strengths of an yeast-derived recombinant hepatitis B vaccine in adolescents. 总被引:2,自引:0,他引:2
2.
Histopathology reports are important quality assurance tools and evaluation of pathological diagnoses described in them is an integral part of total quality control and quality improvement program. We describe a program based on slide circulation which was aimed at both continuing education to upgrade knowledge and proficiency testing of histopathologists. The performance of the participating pathologists was analyzed and the degree of agreement was also studied. The results showed improvement indicated by rising level of performance in 35.3% of consistent participants and increasing trend in the average score. The degree of agreement was comparatively low (65.29%). The practicability of this program and its acceptability as an EQAS was also investigated. 相似文献
3.
Elaine Tierney Irena Bukelis Richard E Thompson Khalid Ahmed Alka Aneja Lisa Kratz Richard I Kelley 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2006,(6):666-668
Although Smith-Lemli-Opitz Syndrome (SLOS), a genetic condition of impaired cholesterol biosynthesis, is associated with autism [Tierney et al., 2001; Am J Med Genet 98:191-200.], the incidence of SLOS and other sterol disorders among individuals with autism spectrum disorders (ASD) is unknown. This study investigated (1) the incidence of biochemically diagnosed SLOS in blood samples from a cohort of subjects with ASD from families in which more than one individual had ASD and (2) the type and incidence of other sterol disorders in the same group. Using gas chromatography/mass spectrometry, cholesterol, and its precursor sterols were quantified in 100 samples from subjects with ASD obtained from the Autism Genetic Resource Exchange (AGRE) specimen repository. Although no sample had sterol levels consistent with SLOS, 19 samples had total cholesterol levels lower than 100 mg/dl, which is below the 5th centile for children over age 2 years. These findings suggest that, in addition to SLOS, there may be other disorders of sterol metabolism or homeostasis associated with ASD. 相似文献
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Maternal and Child Health Journal - While the city offers economic opportunities for women in many countries, their safety and security remain vulnerable to urban violence, especially in poor... 相似文献
6.
The adaptive response is an error-free DNA repair mechanism induced by low levels of physical or chemical agents. Cells pre-exposed to such agents are resistant to genetic damage induced by subsequent treatment at a high dose. There are many reports on such adaptive responses. Recently we have shown the existence of adaptive responses in vivo in the grasshopper Poecilocerus pictus and the mouse and in vitro in human lymphocytes. Different enzymes are implicated in this DNA repair pathway. In an attempt to understand the molecular mechanism of the methyl methanesulfonate (MMS)-induced adaptive response, the present investigations have been undertaken employing nicotinamide, an inhibitor of the DNA repair enzyme poly(ADP-ribose) polymerase (PARP). Pre-, inter- and post-treatments with nicotinamide of MMS-treated mouse bone marrow cells were carried out. The results revealed that there is a significant reduction in the frequency of chromosomal aberrations compared with combined treatment, suggesting an enhancement of the adaptive response by nicotinamide. Further, the results of NAD+ assay in the inter-treatment experiment showed that there is no depletion of NAD+. Thus, it can be stated that PARP is not involved in the MMS-induced adaptive response in mouse bone marrow cells. 相似文献
7.
H. Özbey C. Boneval Ü. Alkaç B. Bavbek G. Çakiroğlu T. Salman A. Çelik 《Pediatric surgery international》1996,11(8):547-549
It is known that polycythemia decreases the fluidity of the blood and impairs tissue perfusion due to red-cell sludging in the microcirculation. In this study, the effect of polycythemic hyperviscosity (PH) on bowel necrosis was evaluated in an experimental model of intestinal ischemia. Twenty-eight Wistar albino rats (90–170 g) were divided into two groups: group 1 was transfused to create hyperviscosity and then intestinal ischemia was produced (n = 16); in group 2 ischemia was produced without transfusion (n = 12). Intestinal ischemia was produced by clamping the superior mesenteric artery and the collateral arcades of the right colic artery for 30 min. Gross and histopathologic evaluations were performed by either immediate necropsy or relaparotomy 24 h later. Microscopic findings were graded from 0 to 3 according to the degree of ischemic changes. In group 1, 2 animals (12.5%) died before 24 h postoperatively; coagulation necrosis with grade 2 or 3 ischemic changes was observed in 10 animals (62.5%). In group 2 only a few hypertrophied Peyer's patches and capillary dilation were found, and all histopathologic changes were between grades 0 and 1. The difference between the histopathologic gradings of the two groups was significant (P < 0.001). It appears that in addition to reduced splanchnic blood flow, a secondary effect of PH is needed to induce ischemic coagulation necrosis. PH of the newborn must be considered a risk factor for necrotizing enterocolitis, so-called spontaneous intestinal perforations, and even intestinal atresia.Presented at the 1st European Congress of Pediatric Surgery, Graz/Austria, May 4–6, 1995 相似文献
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9.
Manthena V. S. Varma Aditya M. Kaushal Alka Garg Dr Sanjay Garg 《American Journal of Drug Delivery》2004,2(1):43-57
Matrix technologies have often proven popular among the oral controlled drug delivery technologies because of their simplicity, ease in manufacturing, high level of reproducibility, stability of the raw materials and dosage form, and ease of scale-up and process validation. Technological advancements in the area of matrix formulation have made controlled-release product development much easier than before, and improved upon the feasibility of delivering a wide variety of drugs with different physicochemical and biopharmaceutical properties. This is reflected by the large number of patents filed each year and by the commercial success of a number of novel drug delivery systems based on matrix technologies. Matrix-based delivery technologies have steadily matured from delivering drugs by first-order or square-root-of-time release kinetics to much more complex and customized release patterns. In order to achieve linear or zero-order release, various strategies that seek to manipulate tablet geometry, polymer variables, and formulation aspects have been applied. Various drug, polymer, and formulation-related factors, which influence the in situ formation of a polymeric gel layer/drug depletion zone and its characteristics as a function of time, determine the drug release from matrix systems. Various mathematical models, ranging from simple empirical or semi-empirical (Higuchi equation, Power law) to more complex mechanistic theories that consider diffusion, swelling, and dissolution processes simultaneously, have been developed to describe the mass transport processes involved in matrix-based drug release. Careful selection of an appropriate model for drug release provides insight to the underlying mass transport mechanisms and helps in predicting the effect of the device design parameters on the resulting drug-release rate. Thus, a basic understanding of release kinetics and appropriate mechanisms of drug release from matrix system and their inter-relationships may minimize the number of trials in final optimization, thereby improving formulation development processes. 相似文献
10.
Evaluation of osteopontin as biomarker for pancreatic adenocarcinoma. 总被引:19,自引:0,他引:19
Jens Koopmann Neal S Fedarko Alka Jain Anirban Maitra Christine Iacobuzio-Donahue Ayman Rahman Ralph H Hruban Charles J Yeo Michael Goggins 《Cancer epidemiology, biomarkers & prevention》2004,13(3):487-491
OBJECTIVES: Pancreatic adenocarcinoma is a deadly disease with an overall 5-year patient survival of less than 5%. This dismal prognosis of pancreatic cancer is largely due to the advanced stage of the disease at presentation. If pancreatic cancer could be diagnosed more readily and accurately using serum markers, patient survival could theoretically be improved by enabling more patients to avail of surgical resection. One candidate tumor marker recently identified by global gene expression analysis of pancreatic cancer is the secreted glycophosphoprotein osteopontin (OPN). In this study, we evaluate OPN as a serum marker of pancreatic adenocarcinoma. METHODS: In situ hybridization for OPN was performed on a pancreatic adenocarcinoma tissue microarray. Serum OPN levels were determined in preoperative sera from 50 patients with pancreatic cancer and 22 healthy control individuals by competitive ELISA. RESULTS: In situ hybridization for OPN performed on a tissue microarray revealed strong OPN mRNA signal in tumor-infiltrating macrophages in 8 of 14 pancreatic adenocarcinomas. In contrast, OPN expression was not seen in the pancreatic cancer cells themselves, nor was it seen in normal pancreatic tissue or in the macrophages distant from the infiltrating cancer. Serum OPN levels, as measured by ELISA, were elevated in the sera of 50 patients with resectable pancreatic adenocarcinoma compared to 22 healthy control individuals (mean +/- SD for OPN was 482 +/- 170 ng/ml and 204 +/- 65 ng/ml, respectively; P < 0.001). Using a cutoff level of 2 SD above the mean for healthy individuals, elevated OPN had sensitivity of 80% and specificity of 97% for pancreatic cancer. In contrast, only 62% of these patients with resectable pancreatic cancer had elevated CA19-9. CONCLUSIONS: Serum OPN may have utility as a diagnostic marker in patients with pancreatic cancer. 相似文献