Stomatitis from dentures: etiopathological and therapeutic considerations

Infection of the oral mucous membrane is frequent in patients with removable prostheses, either totally of partially, and particularly when the prostheses is palatal. The principal etiological factor causing the infection is accepted to be "Candidas" aided by the presence of plaque bacteria (in patients with poor oral hygiene care), and a poor fit of the prostheses to the soft tissues. Treatment of the infection must proceed in the following order: a) use of effective medication against oral fungus such as Nystatin or Ketoconazole. b) Meticulous oral hygiene care in the mucous membrane as well as in the prostheses, but using the prostheses as little as possible during the treatment period. c) A total cure of the infection (denture stomatitis) before proceeding to the next phase of the treatment. d) Determination of the adjustment and occlusion of the prostheses in order to determine those areas of the prostheses which need to be refilled because of maladjustment of the prostheses to the soft tissues of the patient.     

以循证医学的理念观察颈椎综合征的MRI图像

目的鉴于MRI对组织的高分辨性能,利用该图像观察颈椎综合征患者的椎管外组织的病理状况.方法54例患者,其中男30例,女24例,分为2组.观察组44例颈椎综合征患者,对照组10例颈部外伤和三叉神经痛患者.通过常规的MRI矢状位及横轴位颈椎图像,比较两组软组织增生情况.结果与结论在颈椎综合征MRI的颈椎及上段胸椎棘突后侧,均可观察到不同程度的慢性纤维性变化,与对照组比较,有可比性.提示临床上颈椎综合征多与颈肩区筋膜炎、棘突炎相关,属于无菌性炎症,其慢性阶段,局部发生了纤维增生性改变.建议在观察分析此种病症的颈椎骨质及椎间盘改变的同时,宜重视棘突后侧的纤维性变化,有利于病理病因的研究.     

Classification of Breast Masses Using Selected Shape,Edge-sharpness,and Texture Features with Linear and Kernel-based Classifiers

Breast masses due to benign disease and malignant tumors related to breast cancer differ in terms of shape, edge-sharpness, and texture characteristics. In this study, we evaluate a set of 22 features including 5 shape factors, 3 edge-sharpness measures, and 14 texture features computed from 111 regions in mammograms, with 46 regions related to malignant tumors and 65 to benign masses. Feature selection is performed by a genetic algorithm based on several criteria, such as alignment of the kernel with the target function, class separability, and normalized distance. Fisher's linear discriminant analysis, the support vector machine (SVM), and our strict two-surface proximal (S2SP) classifier, as well as their corresponding kernel-based nonlinear versions, are used in the classification task with the selected features. The nonlinear classification performance of kernel Fisher's discriminant analysis, SVM, and S2SP, with the Gaussian kernel, reached 0.95 in terms of the area under the receiver operating characteristics curve. The results indicate that improvement in classification accuracy may be gained by using selected combinations of shape, edge-sharpness, and texture features.     

脚压测量用传感器

本文讨论了用于脚压测量的四类压力传感器，电阻式传感器、压电式传感器，光电式传感器，电容式传感器介绍了其结构、原理和特点，并分析了几种典型的测量接口电路。     

Transmission of HIV-1 infection between trophoblast placental cells and T-cells take place via an LFA-1-mediated cell to cell contact

HIV-1 vertical transmission is thought to mainly take place by virus crossing the placental barrier. However, the mechanism by which HIV-1-infects placental cells remains to be elucidated. We have found that purified cytotrophoblasts as well as trophoblastic cell lines are susceptible to infection by different HIV-1 isolates as detected by DNA-PCR and release of infectious virus, although with very low efficiency. Purified trophoblast or trophoblastic cell lines express low levels of chemokine receptors CCR-5 and CXCR-4 but not CD4 on the cell surface. To test if those molecules were used as receptors for HIV-1 infection, placental cells were pretreated with antibodies to CD4, CC-chemokines, C-X-C chemokines. None of those treatments inhibited HIV-1 infection. In contrast, we have found that HIV-1 infection of placental cells was increased in cocultures of infected T-cell blasts and placental cells. More interestingly, antibodies to beta(2) integrins and to LFA-1 were able to significantly block infection of placental cells. Cell surface expression of ICAM-1, an adhesion molecule involved in attachment of leukocytes to placenta, was upregulated in HIV-1-infected placental cells. Placental cells were able to transfer HIV-1 infection to T-cell blasts. This transmission required cell to cell contact and was also inhibited by anti-LFA-1 antibodies. In summary our results suggest that placental trophoblast could be infected by HIV-1 by a mechanism involving T cell to placental contact. Moreover, placental infection enhanced ICAM-1 expression and leukocyte adherence, an event which was required to transfer HIV-1 infection to T cells. This provides an explanation of the virus passing through the placental barrier during in utero HIV-1 vertical transmission.     

Virilizing mature ovarian cystic teratomas

 Three further cases of mature benign cystic teratomas of the ovary associated with virilization are added to the three previously reported in the literature. They were found in postmenopausal, obese, diabetic women aged 52, 61, and 67 years. The patients presented with hirsutism and voice changes and clitoromegaly was present in one. Testosterone and androstenedione levels were elevated but promptly regressed after removal of the tumours. Histologically, sheets of stromal luteinized cells were found peripherally at the interface between the neoplasm and ovarian tissue. Luteinization of ovarian stroma induced by an unknown factor related to diabetes mellitus is the origin of the virilization. Received: 8 January 1997 / Accepted: 28 February 1997     

Endocarditis with ruptured cerebral aneurysm caused by Cardiobacterium valvarum sp. nov

A fastidious gram-negative bacterium was isolated from the blood of a 37-year-old man who had insidious endocarditis with a sudden rupture of a cerebral aneurysm. Characterization of the organism through phylogenetic and phenotypic analyses revealed a novel species of Cardiobacterium, for which the name Cardiobacterium valvarum sp. nov. is proposed. C. valvarum will supplement the current sole species Cardiobacterium hominis, a known cause of endocarditis. Surgeries and antibiotic treatment cured the patient's infection and associated complications. During cardiac surgery, a congenital bicuspid aortic valve was found to be the predisposing factor for his endocarditis.     

Chemokine receptors that mediate B cell homing to secondary lymphoid tissues are highly expressed in B cell chronic lymphocytic leukemia and non-Hodgkin lymphomas with widespread nodular dissemination

B cell neoplasms present heterogeneous patterns of lymphoid organ involvement, which may be a result of the differential expression of chemokine receptors. We found that chemokine receptor (CCR)7, CXC chemokine receptor (CXCR)4, or CXCR5, the main chemokine receptors that mediate B cell entry into secondary lymphoid tissues and their homing to T cell and B cell zones therein, were highly expressed in B malignancies with widespread involvement of lymph nodes. Conversely, those pathologies with little or no nodular dissemination showed no expression to very low levels of CCR7 and CXCR5 and low to moderate levels of CXCR4. These findings provide evidence for the role of CCR7, CXCR4, and CXCR5 in determining the pattern of lymphoid organ involvement of B tumors. Functional studies were performed on B malignancies expressing different levels of CCR7, CXCR5, and CXCR4. Multiple myeloma (MM) cells did not express CCR7 nor CXCR5 and did not migrate in response to their ligands; a moderate expression of CXCR4 on MM cells was accompanied by a migratory response to its ligand, CXCL12. By contrast, cells from B cell chronic lymphocytic leukemia (B-CLL) expressed the highest levels of these chemokine receptors and efficiently migrated in response to all ligands of CCR7, CXCR4, and CXCR5. In addition, the migration index of B-CLL cells in response to both of the CCR7 ligands correlated with the presence of clinical lymphadenopathy, thus indicating that the high expression of functional chemokine receptors justifies the widespread character of B-CLL, representing a clinical target for the control of tumor cell dissemination.     

Bruceine B, A Potent Inhibitor of Leukocyte-Endothelial Cell Adhesion

Leukocyte adhesion to vascular endothelial cells is an essential step in the development of inflammatory diseases. We have searched for inhibitors of leukocyte-endothelial cell adhesion that could be used as anti-inflammatory drugs and found that bruceine B (0.2 g/ml; 0.44 M) inhibited human neutrophil or T cell adhesion to tumor necrosis factor- (TNF) stimulated human umbilical vein endothelial cells (HUVEC). The inhibition of neutrophil adhesion to TNF-stimulated HUVEC by bruceine B was not derived from cytotoxic effects, as determined by measurement of the level of lactate dehydrogenase (LDH) activity in conditioned medium. The effect of bruceine B on neutrophil adhesion to HUVEC was not seen when the neutrophils were preincubated with bruceine B. However, inhibitory effects were evident when the HUVEC were preincubated with bruceine B. Bruceine B also inhibited neutrophil adhesion to lipopolysaccharide-stimulated HUVEC and T cell adhesion to TNF-stimulated HUVEC. These findings suggest that bruceine B may have anti-inflammatory activity.