Loss in apoptosis competence often results in augmented genomic instability contributing to carcinogenesis. Cytochrome c oxidase subunit I (CcOI) can help assess apoptosis resistance in paraffin-embedded biopsies. In total, 50 colorectal cases including 10 control cases of colectomy for non-neoplastic condition, 15 cases of adenomatous colorectal polyps, and 25 cases of colorectal carcinoma were investigated in this retrospective study for immunohistochemical expression of CcOI. The staining pattern of CcOI was assessed and indices of aberrant expression were calculated as crypt-restricted loss and overall decreased immunostaining (ODI). ODI calculated in the adenocarcinoma tumor tissue was designated as Tr ODI. The crypt-restricted loss and ODI indices of the aberrant CcOI expression are significantly higher in the adenomatous polyps group (2.5% and 47.54%) and in the non-neoplastic mucosa among adenocarcinoma group (2.78% and 49.1%) when they are compared with the control group (0.55% and 7.32%) (P<0.001). A highly significant correlation was noted between Tr ODI and the tumor grade, the nodal status, and the stage among adenocarcinomas. In conclusion, colonic tumors arise in a field of crypts with aberrations in CcOI expression. This aberration is linked to biologically aggressive tumors. CcOI immunostaining may be applied on mucosal samples from patients with colonic adenomatous polyps and patients with previous cancer colon resection to determine individuals who are in need for frequent colonoscopies and/or chemopreventive strategies. Future follow-up studies are warranted to determine the level of expression predictive of recurrence or progression.

Background: Atrophic scars cause significant patient morbidity. Fractional photothermolysis is one of the most effective treatment options used to resurface scars of different etiologies. Aims: To assess the efficacy and safety of different fractional ablative CO 2 laser parameters in treatment of linear atrophic depressed post-traumatic facial scars in adult male patients. Methods: A prospective pilot study of 20 adult male patients (skin types Π-Ⅳ, aged 18-45) with post-traumatic atrophic linear scars were divided into 2 groups each comprising 10 patients receiving different fractional CO 2 laser parameters. Both groups received 3 laser sessions, one month apart, and were followed for 2 months after the last treatment session. Clinical and histological assessments were done to all patients before treatment and 2 months after the last treatment session. Also, patient satisfaction and side effects were recorded. Results: The study showed statistically significant reduction in average scar volume in both groups (P < .01), with reduction in depth more obvious than reduction in width or length in both groups. There was a highly significant difference in overall scar improvement represented by scar volume between both groups (P < .01) with an average reduction in scar volume of 42.85% in group (a) compared with 35.29% in group (b). Also, there was a highly statistically significant increase in both epidermal and papillary and reticular dermis thickness in both groups after treatment. However, the difference between both groups was nonsignificant. Side effects were mild, well tolerated, and transient. Conclusion: Fractional CO 2 laser can be utilized as a safe and effective modality in treatment of post-traumatic linear atrophic scars of the face. Adjusting parameters toward increasing depth of penetration and decreasing thermal coagulative effect gives better results.