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21.
A young boy presented with an uncommon finding of impaction of upper right central incisor and transposition of canine and lateral incisor on the same side. Esthetic management of his cosmetic problem which included fixed appliance therapy followed by light cure restorations is discussed.KEY WORDS: Impaction, Transposition  相似文献   
22.
On the basis of information obtained during a study of former mental patients under a research grant from the state of Florida, the authors point out the critical need for more comprehensive management information systems. Twelve specific steps for designing and implementing such a system are outlined.  相似文献   
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The Dunning H rat prostate tumor (R3327H) is a widely used experimental model of human prostatic adenocarcinoma (CaP). The Dunning H tumor has been characterized as androgen-sensitive, androgen-receptor (AR) positive, prostate-specific antigen and prostatic acid phosphatase (PAP) positive. To date, the tumor has been maintained by serial passage in vivo because of the lack of an in vitro cell line that retains the characteristics of the in vivo tumor. The objective of the present study was to establish a propagable cell line from R3327H adenocarcinoma that maintained androgen sensitivity and expression of AR, PSA and PAP. Tissue harvested from an in vivo R3327H tumor was dissociated with collagenase and placed into Richter's improved media (with supplements). A cytokeratin-positive epithelial cell line (HUNC- E) and a vimentin-positive stromal cell line (HUNC-S) were generated from the primary culture, subcultured continuously for >300 days, and passaged >50 times. Survival of the HUNC-E cell line in vitro depended on several media supplements, including nicotinamide, insulin, transferrin, selenium and epidermal growth factor (EGF). HUNC-E cells expressed AR and produced PSA and PAP throughout the culture period, as confirmed by immunocytochemistry and Western blot analyses. Addition of 14 nM testosterone (T) or dihydrotestosterone (DHT) to HUNC-E cells, stimulated DNA synthesis as well as anchorage-independent growth and PSA production, which demonstrated the androgen-sensitive nature of the cells in vitro. When HUNC-E and HUNC-S cells were combined in a 3:1 ratio and introduced subcutaneously into syngeneic male hosts, tumors formed in 2/3 animals with an average latency of 7 months. RT-PCR and immunocytochemical characterization of the HUNC cell lines revealed that the cells expressed several growth factors and their cognate receptors, including HGF, TGF-alpha and the TGF-betas, indicating the establishment of potential autocrine loops in the neoplastic cells. The HUNC-E and HUNC-S CaP cell lines, which retain the characteristics of the epithelial and stromal components of the in vivo R3327H tumor, will allow a more thorough and informative molecular and biological analysis of prostatic adenocarcinoma.   相似文献   
25.
Fong  LY; Farber  JL; Magee  PN 《Carcinogenesis》1998,19(9):1591-1596
Previous work has shown that sustained increased and decreased cell proliferation, induced by dietary zinc deficiency and caloric restriction respectively, influence the course of N- nitrosomethylbenzylamine (NMBA)-induced esophageal carcinogenesis in rats. The present study considered whether the increased cell proliferation and esophageal tumor incidence induced by zinc deficiency are reversed upon zinc replenishment. Weanling rats were maintained initially on a deficient diet containing 4 p.p.m. zinc. After 5 weeks, carcinogen-treated animals were given six intragastric doses of NMBA (2 mg/kg twice weekly). Controls were untreated. After the second NMBA dose, the rats were divided into three dietary groups. One group was continued on the deficient diet, while the other two groups were switched to diets containing either 75 or 200 p.p.m. zinc, with half of the members in each group fed ad libitum and half pair-fed with deficient rats. NMBA-untreated controls were similarly replenished. At various time points, esophageal cell proliferation was assessed in five animals from each group by immunohistochemical detection of cells in S phase, with in vivo 5-bromo-2'deoxyuridine labeling. At 11 weeks after the first dose, esophageal tumor incidence was greatly reduced, from 100% in the deficient group to 26 and 14% respectively in the replenished groups fed ad libitum 75 and 200 p.p.m. zinc and to 14 and 11% respectively in the replenished groups pair-fed 75 and 200 p.p.m. zinc. In addition, the number of tumors per esophagus was reduced from 9.93 +/- 4.25 in deficient rats, to a range of 0.11 +/- 0.31-0.30 +/- 0.54 in replenished animals. Following zinc replenishment, esophageal cell proliferation, as measured by labeling index (LI), the number of labeled cells and the total number of cells, was markedly decreased in NMBA-untreated and -treated esophagi as compared with those in corresponding deficient esophagi. Thus, the esophageal cell proliferation induced by zinc deficiency is reversed by zinc replenishment and replenished animals have a markedly lower incidence of esophageal tumors.   相似文献   
26.
The effects of Ro 15-1788, a benzodiazepine antagonist with some agonist properties, were studied on adenosine and adenosine 5'-N-ethyl-carboxamide (NECA)-evoked depressions of rat cerebral cortical neuronal activity. Iontophoretically applied Ro 15-1788 had both antagonistic and potentiative interactions with adenosine. Reductions in the magnitude of adenosine-evoked depressions of firing were evident during the period of Ro 15-1788 application, with a long-lasting potentiative effect becoming apparent upon termination of the Ro 15-1788 application. Depressions of cell firing evoked by NECA, an uptake-resistant analog of adenosine, were antagonized by Ro 15-1788, with no subsequent potentiation. Larger applications of Ro 15-1788 had a depressant action on neuronal firing, which was antagonized by caffeine (20 mg/kg), an adenosine receptor blocker. These results indicate that Ro 15-1788 may be an antagonist at the adenosine receptor as well as a potentiator of the adenosine response. The prolongation of the adenosine depression is likely to be the result of a persistent inhibition of adenosine uptake by Ro 15-1788. These diverse effects on the adenosine response may account for some of the complex behavioral actions of Ro 15-1788.  相似文献   
27.
目的探讨宫颈液基细胞学及阴道镜检查在北京市社区妇女宫颈病变筛查中的临床意义。方法2006年6月至2007年6月对北京市展览路社区的795位20~54岁有性生活的妇女进行筛查。筛查对象接受妇科检查时,留取宫颈超柏氏薄层液基细胞学检测标本,并对宫颈细胞学异常者行阴道镜检查及活组织检查。结果宫颈细胞学阳性[≥ASC-US(不能明确意义的不典型鳞状细胞)]45例,占5.7%(45/795)。其中ASC-US33例,占73.3%(33/45);低度鳞状上皮内病变8例;高度鳞状上皮内病变3例;不典型腺细胞1例。细胞学阴性750例,占94.3%(750/795)。宫颈细胞学阳性的45例中,5例拒绝行阴道镜检查,占11.1%(5/45)。在行阴道镜活组织病理检查的40例中,慢性宫颈炎11例(27.5%);宫颈湿疣14例(35.0%);宫颈上皮内瘤样病变(CIN)1为7例(17.5%);CIN2为3例(7.5%);CIN3为4例(10.0%);早期浸润癌1例(2.5%)。细胞学阴性的750例中,宫颈湿疣2例(0.3%);CIN1为5例(0.7%);宫颈低级别腺上皮内病变1例(0.1%)。宫颈液基细胞学筛查CIN1及以上宫颈病变和宫颈癌的敏感度71.4%,特异度94.2%,阳性预测值37.5%,阴性预测值99.2%;筛查CIN2及以上宫颈病变和宫颈癌的敏感度100.0%,特异度96.0%,阳性预测值20.5%,阴性预测值100.0%。结论应重视并及时进行北京市社区人群宫颈病变的早期筛查,薄层液基细胞学结合阴道镜活组织检查及病理学检查,对提高早期宫颈癌筛查的准确性效果明显。  相似文献   
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29.
Arriaga  M; South  K; Cohen  JL; Mazur  EM 《Blood》1987,69(2):486-492
Sera from dogs rendered aplastic by total-body irradiation stimulate human bone marrow megakaryocyte progenitors to form megakaryocyte colonies in plasma clot cultures. In this investigation, we evaluated the effects of varying concentrations of such sera on both the mitotic and endomitotic phases of human megakaryocyte development in vitro. When low concentrations of aplastic canine sera (2.5% to 5.0% [vol/vol]) were added to cultures of human peripheral blood mononuclear cells in place of normal AB serum, megakaryocyte colony formation was augmented fivefold, cell numbers per colony increased approximately 2.5- fold, and the geometric mean megakaryocyte ploidy almost doubled. Further increasing the aplastic canine serum concentration from 10% to 30% (vol/vol) stimulated no additional colony formation. However, there was a further augmentation of cell numbers per colony associated with a progressive decrease in the mean megakaryocyte ploidy. Megakaryocyte cultures were harvested after 7, 12, 15, and 19 days of incubation, and these demonstrated that the lower mean ploidy values found at the higher concentrations of aplastic canine serum did not result from delayed endoreduplication. At all aplastic serum concentrations evaluated, there existed a strong correlation between nuclear ploidy and cell diameter. We conclude that both the mitotic and endomitotic events in human megakaryocytopoiesis may be influenced by a factor or factors present in aplastic canine serum. At lower in vitro concentrations, such sera stimulate both mitosis and endomitosis, which promotes the development of megakaryocyte colonies composed of larger cells with a higher mean ploidy. With increasing aplastic serum concentrations, colony formation plateaus and mitosis is favored over endomitosis. This results in colonies composed of more numerous but smaller megakaryocytes with a lower mean ploidy. Our data suggest that the size and extent of polyploidization that can be achieved by a developing megakaryocyte may be influenced by the mitotic prior history of its immediate precursor cell.  相似文献   
30.
Human cytomegalovirus (CMV) infection is often associated with myelosuppression and acute inflammatory reaction in immunocompromised patients. We have previously documented that CMV exposure of bone marrow (BM) stromal cells reduces the capacity of these cells to support hematopoiesis because of a decreased production of colony- stimulating factors. This study examines the potential role of CMV on constitutive and lipopolysaccharide (LPS)-stimulated production of cytokines involved in inflammatory reaction, interleukin-6 (IL-6) and leukemia inhibitory factor (LIF) by BM stromal cells. The release of IL- 6 was already detectable 2 hours post CMV-infection (2.5-fold increase in production) and the cumulative production of IL-6 after 5 days of infection was 23 +/- 1.2 ng/mL (ninefold increase in production). CMV was also able to induce a time-dependent production of LIF that was maximal 8 hours after CMV infection (2.5-fold increase in production). Concomitantly, there was no detectable release of granulocyte colony- stimulating factor (G-CSF) and granulocyte-macrophage CSF (GM-CSF) by CMV-infected stromal cells. The similar IL-6 and LIF production in the presence of polymyxin B ruled out the possibility that this increase could be caused by contamination of the viral stock by endotoxin. In addition, ultraviolet-inactivated virus behaved similarly to live virus and caused the release of IL-6 and LIF. However, heat-inactivated CMV was unable to induce IL-6 and LIF secretion by BM stromal cells. The production of IL-6 and LIF was also evaluated after stimulation by LPS. After 5 days of CMV exposure, the LPS-stimulated production of IL-6 and LIF was significantly lower than uninfected controls. This LPS-induced release of cytokine production was found to be dependent of viral replication. The experiments have shown that CMV is a potent inducer of IL-6 and LIF with differential effect on constitutive and LPS- stimulated cytokine production by stromal cells; we suggest that CMV induction of IL-6 and LIF during the first hours of infection could play a role in CMV-induced inflammatory reaction. Moreover, our results show that human CMV can disturb the balanced cytokine network involved in the regulation of hematopoiesis.  相似文献   
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