Low-level laser has been indicated to have the capability to facilitate the differentiation of the osteoclastic and osteoblastic cells which are responsible for the bone remodeling process. The aim of this study was to evaluate the effects of InGaAlP laser with a wavelength of 660 nm on the rate of tooth movement and histological status. Thirty male Wistar rats of 7 weeks old were selected for this study. The rats were randomly divided into two groups of 15 each to form the experimental (laser-irradiated) and control (non-irradiated) groups. The control group received unilateral orthodontic appliance design (one quadrant), but the laser-irradiated group received split-mouth design, with orthodontic appliance on both sides and laser irradiation on one side only (group b) and on the contralateral side (group c). The orthodontic appliance consisted of a NiTi closed coil spring with a length of 5 mm which was ligated to maxillary molar and incisor. A total of 60 g of force was applied to the rat molar. The diode laser (660 nm) was irradiated with an output power of 25 mW in continuous mode for a total time of 5 min in the laser-irradiated group. After 14 days of orthodontic tooth movement, the amount of tooth movements was measured. In the laser-irradiated group, the amount of tooth movement was significantly greater than that of the non-irradiated group (2.3-fold), but there was no significant difference between the non-irradiated and indirectly irradiated groups. Histopathological studies revealed that the number of osteoclasts in the laser-irradiated group was significantly greater than that of the non-irradiated group (1.5-fold) while this number was almost the same in the non-irradiated and indirectly irradiated groups. The results suggested that low-level laser can accelerate the rate of bone remodeling. However, in order to utilize the low-level laser as an adjunct in orthodontic practice on patients, further research studies are needed for finding the appropriate dosage for the human tissues.
Developing cancer gene therapy constructs based on transcriptional targeting of genes to cancer cells is a new and promising modality for treatment of cancer. Introducing truncated Bid (tBid), a recently known member of the Bcl-2 family, eradicates cancer cells efficiently. For transcriptional targeting of tBid, two dual-specificity promoters, combining cancer specific core promoters and response modules, were designed. These two core promoter modules contained cancer specific promoters of MUC1 and Survivin genes accompanied by hypoxia-responsive elements and estrogen responsive elements (microenvironment condition of breast cancer cells) which were employed to achieve a higher and more specific level of tBid expression in breast cancer cells. Correlation of the level of tBid expression in normal and cancer cell lines with promoter activity was measured by RT-PCR after treatment with hypoxia and estrogen. The level of tBid expression under control of new hybrid promoters was compared with its expression under control of cytomegalovirus (CMV) promoter as a control. Our data revealed that the level of tBid expression in breast cancer cells were nearly 11 times more than normal cells because of the cancer specific promoters, although tBid expression under control of CMV promoter was almost the same in normal and cancer cell lines. Increased apoptosis was detected in the transfected breast cancer cell lines by the Caspase-3 activity assay. The application of these promoters may prove to have the advantage of tumor selective gene therapy in breast cancer cells and low-potential toxicity for normal tissues.
Background: HIV rapid tests (RT) are a quick and non-technically demanding means to perform HIV voluntary counselling and testing (VCT) but understanding their limitations is vital to delivering quality VCT. Objective: To determine the sensitivity and specificity of HIV rapid tests used for research and voluntary counselling and testing at four sites in East Africa. Design: Cross-sectional study. Setting: Masaka District, Uganda; a sugar plantation in Kakira, Uganda; Coastal Villages in the Kilifi District of Kenya; and the Urban slum of Kangemi located West of Nairobi, Kenya. Subjects: Six thousands two hundred and fifty five consenting volunteers were enrolled into the study, and 675 prevalent HIV infections were identified. Results: The RT sensitivity tended to be high for all assays at all sites (97.63-100%) with the exception of the Uni-Gold assay (90.24% in Kangemi, 96.58% in Kilifi). Twenty four RT results were recorded as 'weak positives', 22 (92%) of which were negative by ELISA. There was a high rate of RT false positives in Uganda (positive predictive values ranging from 45.70% to 86.62%). Conclusions: The sensitivity and specificity of the RT varied significantly across sites. The rate of RT misclassification in Uganda suggests that a multiple test algorithm may be preferable to a single test as screener for HIV VCT.
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