---

Background and Objective: Superficial pigmented lesions are the most common complaint in dermatology. This study was done to assess the therapeutic effect of cryotherapy in facial lentigo and junctional nevus. Materials and Methods: In this descriptive study, 100 cases of flat-pigmented lesions with diameters up to 2 mm and after taking a photograph with USB microscope M2 (Scalar) treated with one freeze thaw cycle with liquid nitrogen through an applicator for 2 second in Imam Reza hospital, Mashhad, Iran during 2004-05. The patients were visited 3 times again through 3 successive months. According to the decrease in color of the lesion, patients were divided into 4 groups: sever pigmentation, no response, partial (>50% color loss) and complete response (<50% color loss). Data were analyzed using SPSS-11.5 and Wilcoxon test. Results: 96% of our patients were female and 4% were male. Mean age was 30±11.7 years. Based on Fitzpatrick criteria fifteen patients had type 2, fifty had type 3 and 35 had type 4 skin color. After the period of 3 months follow up, 6% of the patients completely healded, 58% had partial response, 31%with no response and 5% develop hyperpigmentation. Response in patients with type 2 Fitzpatrick skin color was clinically better than type 3 and 4 but this difference was not significant. Conclusion: Cryotherapy is considered as a simple, cost effective and safe therapeutic regiment in treating of 64% facial pigmental lesions.

---

Background and Objective: Micro-ribonucleic acids (microRNAs) have introduced a new field in the molecular diagnosis of cancer. However, the role of circulating microRNAs in the plasma/serum of colorectal cancer patients is still unclear. This study was conducted to determine the expression of let-7d microRNA in patients with colorectal cancer.
Methods: This case-control study was conducted on 40 patients with colorectal cancer and 40 healthy people. In this study, 7 mL blood samples were collected from patients with colorectal cancer (both before and after tumor resection) and healthy individuals (only once). The serum samples were isolated and stored at - 80°C until molecular analysis. MicroRNAs were extracted from serum samples, and cDNA was synthesized. Let-7d expression was examined using the RT-qPCR method. Data were analyzed using GraphPad Prism v. 9 software. The receiver operating characteristic (ROC) curve analysis, sensitivity, and specificity were also calculated for the let-7d microRNA data to introduce a diagnostic biomarker between the preoperative patient group and the control group.
Results: In the preoperative samples of the patients, the expression of let-7d microRNA was significantly lower than that of the control group (P˂0.05). The expression of let-7d microRNA significantly increased after tumor resection compared to before. The ROC analysis for let-7d microRNA in the preoperative patient group with the control group showed that the sensitivity was 33.3%, specificity was 92.3%, and the area under the curve (AUC) was 0.622.
Conclusion: Let-7d microRNA could potentially serve as a new noninvasive diagnostic biomarker for the early detection of colorectal cancer. However, further studies are required on this subject.