Taking into account the problem that the intensity in homogeneity effect of the image segmentation results, this paper proposes a new signal pressure function. First of all, Edge-based GAC (Geodesic Active Contours) model and region-based C-V (Chan-Vese) model are introduced, then SBGFRLS model (Selective Binary and Gaussian Filtering Regularized Level Set model)is being extracted, and a new signed pressure force (SPF) function is used, so that the method can deal with the image of intensity in homogeneity. The proposed method pays more attention to the details of the image, getting a more accurate segmentation results.

Edge detection is the first step for image segmentation in image processing. So far there are many algorithms for edge detection. In the paper, a novel algorithm about edge detection is based on the median filtering and Sobel operator. It has strong immunity of noise, edges exquisite and better recognition compared to ordinary sobel operator.

BACKGROUND & OBJECTIVE:HLCDG1, which locates in chromosome 5q33 (between D5S436 and D5S470),is a novel gene that our laboratory has cloned recently. The expression of HLCDG1 gene was significantly down-regulated or deleted in the primary lung carcinoma. This study was designed to observe if HLCDG1 has the potential to suppress growth of lung carcinoma cells.METHODS:The recombinant plasmid, pcDNA3.1(+)/HLCDG1, was constructed and subsequently transfected into A549 cells through liposome transfection. The A549 cells stably expressing HLCDG1 gene were established by G418 selection. RT-PCR was used to demonstrate the expression of HLCDG1 gene. Furthermore, the cell proliferation assay, the soft agar assay, and the tumorigenesis assay were used to analyze the malignant phenotype of the HLCDG1-transfected cells.RESULTS:The HLCDG1-transfected cells exhibited the expression of HLCDG1 mRNA by RT-PCR. The population double time (PDT) of HLCDG1-transfected group, vector-transfected group, and nontransfected group were 70.0 hours, 43.3 hours, and 39.5 hours, respectively; the difference between HLCDG1-transfected group and the other two groups was significant (P< 0.05). The colony formation rates of HLCDG1-transfected group, the vector-transfected group, and nontransfected group were 8.5%, 29.0%, and 35.0%, respectively. The rate of HLCDG1-transfected cells was markedly lower than those of the other two groups (P< 0.05). Moreover, these clones were injected into athymic nude mice. After 43 days, they were killed, and their tumors were isolated. These tumors weighed 0.120g, 0.612g, and 0.924g, respectively.CONCLUSION:The expression of HLCDG1 in A549 cells may have the potential to suppress tumor cell growth and the tumorigenesis of A549 cells transplanted in nude mice. These results suggested that HLCDG1 gene might be a good candidate of tumor suppressor gene correlated with lung carcinoma.

By screening a human adult cDNA library using a cDNA fragment (AF10056) as a probe, which is significantly down-regulated in laryngeal carcinoma and represents a novel gene, a cDNA, LCRG1(laryngeal carcinoma related gene 1) was identified, which was significantly down-regulated in 12 of 30(40%) primary laryngeal carcinomas and in 6 of 11(54.5%) various cancer cell lines. This gene, localized on chromosome band 17q12--21.1 by alignment of it with STS markers, was composed of six exons and spaned about 60 kb of genomic DNA with a 3.4 kb mature transcript. The putative protein encoded by this gene was 288 amino acid with no significant homology with any known proteins in databases. LCRG1 was expressed in many tissues, as shown by MTN blot analysis. These data suggest that LCRG1 is related to the laryngeal carcinoma.