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81.
OBJECTIVE: To investigate the retraction time, forces, and torques applied to the football helmet during removal of the face mask with different face-mask removal tools. DESIGN AND SETTING: Subjects retracted the face mask of a football helmet mounted to a force platform in a laboratory setting. They removed a standard face mask by cutting or removing (or both) the lateral plastic loop straps using 4 different tools: the Trainer's Angel (TA), FM Extractor (FM), power screwdriver (SD), and Quick Release System (QR) in a counterbalanced fashion. SUBJECTS: Eighteen certified athletic trainers participated in this study. MEASUREMENTS: We started measuring time when the subject picked up the tool and ended when the face mask was in a fully retracted position. Maximum forces and torques were measured from the force platform during the retraction process. RESULTS: The SD and QR retracted the face mask significantly faster than the TA and FM. Forces producing superior-inferior translation were least with the SD. The SD and QR produced less lateral translation and rotation and lateral flexion moment than the TA and FM. The FM produced less torque in the lateral flexion moment than the TA. CONCLUSIONS: Tools that removed the loop straps (SD, QR) were faster and produced less force and torque on the helmet than the tools that cut through the loop straps (TA, FM).  相似文献   
82.
Reactive oxygen species (ROS), represented by superoxide, hydrogen peroxide and hydroxyl radicals, have been implicated in many diseases including cancer. ROS have been known to play an important role in the initiation and promotion of multistep carcinogenesis. The cellular antioxidants play a crucial role in protection against neoplastic disease. However, very little is known about the antioxidant defense in cervical carcinoma. This is addressed in the present study. Lipid peroxides, glutathione content and the activities of antioxidant enzymes, together with vitamin C and E content, were estimated in patients who had carcinoma of the cervix, and the values were compared with those of normal women. The results showed a remarkable reduction in the content of glutathione, vitamin E and C. Activities of glutathione peroxidase and superoxide dismutase were also reduced in cervical cancer compared to normal controls (P < 0.001). This reduction was more marked in late stages (III, IV) than in early stages (I, II) (P < 0.001). Glutathione was reduced more in poorly differentiated tumors (grade III) than in well and moderately differentiated ones (grade I, II) (P < 0.05). Levels of lipid peroxides were found to be significantly higher in malignant than in normal tissue samples and their levels were correlated with advanced clinical stage (P < 0.001). Our results suggest impaired antioxidant status in carcinoma of the cervix. This impairment is related to tumor progression.  相似文献   
83.
颈椎椎间盘的解剖学测量   总被引:6,自引:0,他引:6  
颈椎椎间盘退变及病变是引起颈肩痛的常见原因之一。近年来许多学者对颈椎椎间盘的形态学及生物力学特征作了较系统的研究。但以往认为颈椎间盘突出症较少见。对颈椎髓核位置、椎间盘前、中、后三部分高度解剖学测量的文献报道较少。本研究在青年新鲜尸体的颈椎上。对颈椎髓核位置、椎间盘前、中、后三部分高度等,做了较为系统的解剖学测量。旨在为人体解剖学积累资料,为临床应用提供形态学依据;并对其临床意义进行了讨论。  相似文献   
84.
The total hemolytic complement activity of CH50 and its fractions C3 and C4 was determined in the sera of 196 patients with carcinoma of the oral cavity, 172 patients with carcinoma of the uterine cervix, and 166 patients with breast cancer. The values were compared with those of 18 patients with mammary dysplasia, 32 patients with mild to moderate dysplasia of the cervix, and 100 healthy, normal age- and sex-matched controls. No alterations in CH50, C3, and C4 were observed in the sera of patients with benign lesions, whereas a significant rise in the three factors was observed in all the cancer patients studied. The complement activity increased significantly with the progression of the disease up to stage III and remained persistently elevated thereafter. Patients who had a clinical cure had normal levels of CH50, C3, and C4, whereas the values remained elevated in patients who were still undergoing treatment for residual lesions.  相似文献   
85.
The relationship between the numerical aberrations of chromosome 7 in interphase cells and the clinicopathological behavior of breast tumors was investigated in 51 touch imprinted preparations of breast tumors. Using fluorescence in situ hybridization with a chromosome 7-specific DNA probe, the fluoresceinisothiocyanate (FITC) spots mean and the representative copy number of each breast tumor were examined. The FITC spots mean (2.34) of 40 breast cancers increased compared with that of 11 benign lesions (1.98) (P < 0.02). The FITC spots mean tended to increase with the advancing stage and tumor size of the breast cancer. The FITC spots mean in the case with metastasis was also of a higher value than that without metastasis (P < 0.01). Furthermore, the existence of trisomy or over-trisomy of the copy number was related to the advancing stage and tumor size (P < 0.05 and P < 0.01, respectively). These findings suggest that the FITC spots mean and polysomy of the number of chromosome 7 may be highly predictive for breast tumor aggressiveness.  相似文献   
86.
Summary Two cases of renal epithelial tumours are reported in females aged 46 and 66 years respectively. In spite of the large size of the tumours, neither invasive growth nor metastasis was observed. Histologically, the tumours were composed of immature epithelial cells forming tubules with abortive glomeruloid structures. Electron microscopy of tumour cells revealed poorly developed polarity and intracytoplasmic organelles. They showed similar immunohistochemical reactions to those of developing nephrons, particularly to those of the S-shaped body. The nuclear DNA content of the tumour cells was almost euploid. We conclude that the lesions were epithelial tumours of the kidney histologically mimicking developing renal parenchyma.  相似文献   
87.
Expression of syndecan-1, a cell surface proteoglycan that binds growth factors and extracellular matrix components, was studied in normal and pathological human uterine cervix using immunohistochemical methods. Normal cervical squamous epithelium showed positive staining for syndecan-1 in all cell layers, except the basal cell layer, whereas endocervical columnar epithelium stained weakly. In non-neoplastic reactive lesions, metaplastic squamous cells were positive for syndecan-1, whereas columnar cells showed weak or negative staining. In cervical condylomas, cells showing koilocytotic atypia were positive for syndecan-1. The progression of cervical intraepithelial neoplasia (CIN) grade I to grade III was associated with reduced syndecan-1 expression and localization of syndecan-1 to more superficial cell layers. In squamous cell carcinomas (SCCs), syndecan-1 expression correlated with histological differentiation, being absent from most poorly differentiated tumours. The results suggest that loss of syndecan-1 from atypical cells is an early event during cervical carcinogenesis and show a close association of syndecan-1 expression with preserved epithelial morphology and differentiation.  相似文献   
88.
Mechanisms regulating the content of the putative peptide transmitters, substance P and somatostatin, were examined in several neuronal populations in culture. Substance P levels increased more than 25-fold within 48 h in sympathetic neurons in the explanted rat superior cervical ganglion, and remained elevated for 4 weeks. Identity of the peptide was authenticated by combined high pressure liquid chromatography-radioimmunoassay. Veratridine prevented the increase of substance P in vitro, and tetrodotoxin blocked the veratridine effect, suggesting that sodium ion influx and membrane depolarization prevent peptide elevation. Veratridine (or potassium)-induced membrane depolarization released substance P into the culture medium through a calcium-dependent process. Consequently, at least some veratridine effects are attributable to release and subsequent depletion of ganglion peptide. However, the inhibitory effects of veratridine were far greater than could be accounted for by the quantity of peptide released, suggesting a separate influence on net synthesis (synthesis less catabolism) of substance P. Viewed in conjunction with previous in vivo studies, our observations suggest that trans-synaptic impulses, through the mediation of postsynaptic sodium flux, release substance P from sympathetic neurons and also regulate intracellular peptide metabolism. To determine whether the processes regulating substance P in sympathetic neurons reflect generalized mechanisms, a different peptide, somatostatin, was examined in sympathetic neurons; moreover, substance P was examined in a different neuronal population, special sensory neurons in the nodose ganglion. Substance P levels increased significantly in both sympathetic and sensory neurons after explantation, and somatostatin levels increased in sympathetic neurons. In each instance, the increase was dependent upon the presence of the calcium ions. Moreover, these increases were all prevented by veratridine, in a tetrodotoxin-sensitive manner. Our observations suggest that common regulatory mechanisms govern peptide transmitter metabolism in diverse neuronal populations.  相似文献   
89.
双开门椎板成形椎管扩大术治疗多节段脊髓型颈椎病评价   总被引:2,自引:1,他引:2  
目的:报道双开门式椎板成形椎管扩大术治疗多节段脊髓型颈椎病的临床疗效。方法:观察和分析作者在1999~2001年期间,采用双开门式椎板成形椎管扩大术治疗多节段脊髓型颈椎病35例患者。随访40.6个月(26~56个月)。比较患者术前术后的JOA评分和X线片及CT或MRI改变。结果:末次随访JOA评分改善率:优28.6%(10例),良37.1%(13例),一般22.9%(8例),差11.4%(4例)。JOA评分为(12.6±3.5)分(9~17分),与术前JOA评分情况比较差异有显著性(P<0.01)。神经功能改善率为88.6%,优良率为65.7%。X线片及CT或MRI显示:术后椎管矢状径和椎管面积增加,两者与术前测量结果比较差异均有显著意义(P<0.01)。结论:双开门式椎板成形椎管扩大术治疗多节段脊髓型颈椎病,可通过扩大颈椎管,使脊髓后移而获得减压;只要操作得当,可取得满意疗效。  相似文献   
90.
Extensive immunohistochemical analyses of the hyperplastic human palatine tonsil disclosed variegated B cell phenotypes on the lymphoid cells among the crypt epithelium. The reticular epithelial network was evident by cytokeratin immunostaining. The reticular epithelium near the crypt Iumen was positive for Iysozyme. Secretory component was negative, while HLA-DR was frequently expressed. Intramucosal small Iymphocytes, densely distributed in the Iuminal side, consisted mainly of B cells expressing CD19, CD20, CD21, CD22, CD45R, CD74, DBB42, HLA-DR, HLA-DQ, bcl-2 protein and surface lgM. Some B cells revealed mantle zone phenotypes (surface IgD+, CD5+, CD24+, DBA44+, CD10--, DNA7--). Cells of germinocyte phenotype (CD10+, DNA7+) were sparsely seen. A good number of intramucosal lymphoid cells were further labeled for CD11b, a phenotype of so-called B-1 cells. Plasma cells were clustered within the basal half. IgG was their major immunoglobulin class, followed by IgA, IgM and lgD classes. A smaller number of T cells (CD2+, CD3+, CD5+, CD45RO+, TCR αβ+) were identified among the epithelium. CD4+ cells predominated over CD8+ cells. TCR γΔ + cells were rare. Macrophages (CD68+), dendritic histio-cytes (S-100 protein+, CD1+), and natural killer cells (CD16+ or CD57+) were also dispersed. Another unique feature of this lymphoepithelial complex was the existence of HLA-DR intramucosal microvasculature, where lymphocyte recirculation was suggested. Proliferating cell nuclear antigen was detected commonly in the epithelial cells but rarely in the lymphoid cells. Possible lymphoepithelial interactions and morphologic similarities to the thymic medulla are discussed.  相似文献   
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