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91.
S. Friedman R. Komorowski W. Maillet H. Q. Nguyen C. D. Torneck 《Dental traumatology》1998,14(5):225-231
Abstract— NdYAG laser-induced modification of the root surface may inhibit development of external inflammatory resorption in replanted teeth. This study tested this hypothesis in vivo. The pulp chambers of six mandibular premolars in each of two dogs were accessed, inoculated with plaque, and sealed (Groups 1, 2). Two additional premolars in each dog were endodontically treated without inoculation (Groups 3, 4). After 2 weeks, teeth were hemisected and extracted. Each root had a 2times3 mm surface area denuded of cementum on the buccal and lingual surface. In Groups 1 (n= 12 roots) and 3 (n=4), the denuded surfaces were wiped with 15% EDTA, coated with black ink, and irradiated with Nd:YAG laser (0.75 W, 15 ppc, 300 pm tip, 20 s). In Groups 2 (n= 12) and 4 (n= 4), the surfaces were wiped with 15% EDTA, and rinsed with sterile saline for 20 s. Roots were replanted within 5 min. The dogs were perfwion-euthanised 10 weeks after replantation. Block specimens were removed, decalcified, embedded and horizontally sectioned (6 pm) at 180-pm intervals, resulting in 10 to 14 cross-sections of each root. From these, the middle five consecutive sections were stained with hematoxylin and eosin, and observed by light microscopy for occurrence of surface, inflammatory and replacement resorption on the denuded surfaces. No obvious differences were noted between the laser-irradiated and non-irradiated surfaces. Inflammatory resorption was frequent in Groups 1 and 2, and absent in Groups 3 and 4. Replacement resorption was minimal in Groups 1 and 2, and frequent in Groups 3 and 4. Differences between Groups 1 and 2, and between Groups 3 and 4 were not significant, whereas the differences between the two pairs of groups were statistically significant (chi-square and two-way ANOVA, P>0.006). These results did not support the hypothesis, and questioned the clinical validity of the surface modification in NdYAG laser-irradiated den-tin. Therefore, the clinical application of NdYAG laser to the root surfaces of replanted teeth is not warranted. 相似文献
92.
金地鼠颊囊癌前病变的细胞增殖动力学研究 总被引:2,自引:0,他引:2
目的研究口腔上皮组织癌和癌前病变的细胞动力学变化特征。方法采用Saley的DMBA涂布诱导法,建立金地鼠颊囊癌前病变模型,并用溴脱氧尿苷流式细胞动力学检测方法,对30只叙利亚种金地鼠进行分组对照研究。结果涂药组光镜下的细胞病变程度随涂药时间延长而逐渐加重,而空白对照组无变化;FCM检测显示涂药组与对照组在S期阳性细胞检出率存在显著差异。即使在光镜下表现为轻度不典型增生时,FCM检测结果也有显著差别。结论金地鼠颊囊癌前病变具有细胞异常增殖的细胞动力学特征 相似文献
93.
Q. Peng J. Moan Jahn M. Nesland Jan F. Evensen M. Kongshaug C. Rimington 《Lasers in medical science》1990,5(4):399-409
Observations on time-dependent localization of tetra(3-hydroxyphenyl)porphin (3-THPP) in human malignant melanoma transplanted to athymic nude mice from 1 to 120 h after intraperitoneal (i.p.) 10 mg kg–1 b.w. administration were made by means of fluorescence microscopy. Fluorescence was found on the membrane of the melanoma cells and in the cytoplasm with a peak fluorescence intensity at 24 h post-injection of 3-THPP. The growth of the tumour cells was obviously inhibited at an early stage after PCT. Morphological changes of the tumour at various intervals after treatment by PCT with 3-THPP were also observed. Diffuse degeneration of the tumour cells with swelling of mitochondria and endoplasmic reticulum, heterochromatin aggregation and margination, etc., and subsequently diffuse necrosis with little or no the background of tumorous vascular response were found at an early stage after PCT. On the other hand, it was also observed that the necrosis of the melanoma areas was caused as a consequence of tumorous vascular injury at a later stage after PCT. Thus, two tumoricidal processes caused by PCT with 3-THPP were seen: a direct phototoxic action on tumour cells at an early stage after PCT and an indirect effect secondary to tumorous vascular injury at a later period after PCT. 相似文献
94.
Poverty, health services, and health status in rural America 总被引:5,自引:0,他引:5
Access to health services for everyone has been a major policy goal in the United States: inequitable access is assumed to lead to inequitable health status, particularly for low-income groups. A sophisticated model of the relation between poverty, health care needs, service use, and health outcomes is used to analyze cross-sectional data on 7,823 adults from 36 rural communities. Improved access and use are helpful, but evidence clearly indicates that combined health and social initiatives will be necessary to reduce inequalities in health status. 相似文献
95.
钙拮抗剂TMB-8抑制BHQ,NE和KCl引起的培养乳牛基底动脉单个平滑肌细胞内游离钙的升高 总被引:1,自引:0,他引:1
用AR CM MIC阳离子测定系统,测量单个细胞内游离钙浓度([Ca2+]i),研究8-(N,N-二乙胺)-n-辛基 3,4,5-三甲氧基苯甲酸酯(TMB-8)对培养乳牛基底动脉平滑肌[Ca2+]i的作用。在细胞外钙浓度为1.3mmol·L-1时,TMB-8(30μmol·L-1)可明显抑制BHQ,NE及KCl引起[Ca2+]i的升高。在细胞外钙为零+EGTA 0.1mmol·L-1时,TMB-8(10,30及100μmol·L-1)可浓度依赖性地降低静息[Ca2+]i,TMB-8(30μmol·L-1)可几乎完全阻断BHQ及NE引起[Ca2+]i的增加。研究表明TMB-8降低培养乳牛基底动脉平滑肌[Ca2+]i的机制,主要是抑制肌浆网Ca2+的释放,或增加肌浆网对Ca2+的摄入,并由此间接地抑制细胞外钙的内流。 相似文献
96.
Dr W. Q. Ge Z. C. Luo J. Jin Y. C. Huang S. Wang S. J. Lui 《Medical & biological engineering & computing》1998,36(1):22-26
A novel cardiokymograph system is introduced. The new system features a capacitance transducer with increased sensitivity
and can be used in multichannel measurements. The novelty of this technique is the injection of a current into the patient
coupled with the use of a capacitive displacement transducer and the possibility of multichannel monitoring. It provides for
the possibility of removing breath noise when some signal processing technique, such as adaptive filtering, is used. Further
investigation is needed to demonstrate clinical significance and pathologies. 相似文献
97.
98.
99.
ClassIinterferonisapotent1mmunemodu-latingfactorinvivo,andplaysanimportantrolelnactivatinganti-tumorcytotoxicTlymphocytesandnonuspecificeffectorcellssuchasNKcellsLlJ.ln-terferonandmanyothercytokinegeneswereintro-ducedintotumorcells,tumorinterstitialcellsandtumorinfiltratinglymphocytes['-']inordertosustainaneffectiveanti-tumorconcentrationofcy-tokinelocatedattumorsites.Itwasshownthatsomecytokinegenemodifiedtumorcellslosttheirtumorigenicityandinhibitedthegrowthofparentaltumorinanimalmodels.Pra… 相似文献
100.
Abstract: A prospective, randomized study was conducted to evaluate the role of vitamin B12 and folinic acid supplementation in preventing zidovudine (ZDV)-induced bone marrow suppression. Seventy-five human immunodeficiency virus (HIV)-infected patients with CD4 + cell counts < 500/mm3 were randomized to receive either ZDV (500 mg daily) alone (group I, n = 38) or in combination with folinic acid (15 mg daily) and intramascular vitamin B12 (1000 μg monthly) (group II, n = 37). Finally, 15 patients were excluded from the study (noncompliance 14, death 1); thus, 60 patients (31 in group I and 29 in group II) were eligible for analysis. No significant differences between groups were found at enrollment. During the study, vitamin B12 and folate levels were significantly higher in group II patients; however, no differences in hemoglobin, hematocrit, mean corpuscular volume, and white-cell, neutrophil and platelet counts were observed between groups at 3, 6, 9 and 12 months. Severe hematologic toxicity (neutrophil count < 1000/mm3 and/or hemoglobin < 8 g/dl) occurred in 4 patients assigned to group I and 7 assigned to group II. There was no correlation between vitamin B12 or folate levels and development of myelosuppression. Vitamin B12 and folinic acid supplementation of ZDV therapy does not seem useful in preventing or reducing ZDV-induced myelotoxicity in the overall treated population, although a beneficial effect in certain subgroups of patients cannot be excluded. 相似文献