Parkinson's disease (PD) is known as a progressive neurodegenerative disorder associated with the reduction of dopamine-secreting neurons and the formation of Lewy bodies in the substantia nigra and basal ganglia routes. Aging, as well as environmental and genetic factors, are considered as disease risk factors that can make PD as a complex one. Epigenetics means studying heritable changes in gene expression or function, without altering the underlying DNA sequence. Multiple studies have shown the association of epigenetic variations with onset or progression of various types of diseases. DNA methylation, posttranslational modifications of histones and presence of microRNA (miRNA) are among epigenetic processes involved in regulating pathways related to the development of PD. Unlike genetic mutations, most epigenetic variations may be reversible or preventable. Therefore, the return of aberrant epigenetic events in different cells is a growing therapeutic approach to treatment or prevention. Currently, there are several methods for treating PD patients, the most important of which are drug therapies. However, detection of genes and epigenetic mechanisms involved in the disease can develop appropriate diagnosis and treatment of the disease before the onset of disabilities and resulting complications. The main purpose of this study was to review the most important epigenetic molecular mechanisms, epigenetic variations in PD, and epigenetic-based therapies.

Objective: Cervical cancer is the third most common malignancy in females. Since the human papillomavirus (HPV) genotype can vary geographically, it is essential to define its genotypic distribution before establishing health care policies and vaccination programs in any given area. The aim of this study was to determine the frequency of HPV types in women in Mashhad, Iran. Methods: We used nested PCR and reverse dot-blot hybridization for genotyping. The study included 143 cervical cytology samples from Mashhad with confirmed papillomavirus infection by molecular methods. Results: We found that 74.1% of HPV types were in high-risk groups, including genotypes 16, 18, 39, 52, 58, 66, 68, and 73. Coinfection was detected in 56.4% of the cases. The low-risk group, comprising 25.9%, included genotypes 6, 11, 42, and 44/55. Conclusions: Prevention, early diagnosis, and early treatment have been proven to reduce the mortality rate of cervical cancer. Therefore, an accurate diagnosis of the genotype of the virus in infected patients is very important.