The Character of Reverse Obliquity Intertrochanteric Fractures in Elderly Patients

PURPOSE: To discriminate the characteristics between reverse obliquity fractures in the elderly and that of young adults using three-dimensional computed tomography (3D CT). MATERIALS AND METHODS: Eighteen patients who had reverse obliquity intertrochanteric fractures were enrolled from January 2007 to March 2012. The fracture pattern was analyzed using the 3D CT. The area showing low density (bone defect) of trochanter and femoral neck region was measured. Patients were divided into two groups: Group I, less than 65 years old and Group 2, 65 years and over. RESULTS: In all 9 cases of group 1, the proximal fragment had a 'V' shape with an average of 5.6 cm below the vastus ridge; however, the fracture of 8 cases (88.97%) in group 2 had a 'Lambda' shape of the distal fragment at the level of vastus ridge and an additional fracture line extending to the greater trochanter tip. The bone defect volume of the trochanter and femoral neck region was larger significantly in group 2 than in group 1. CONCLUSION: Reverse obliquity intertrochanteric fracture in the elderly demonstrated a pattern of bursting fracture with 4 parts, which had different patterns from that of young patients. We believe that the larger volume of bone defects resulted in the difference of fracture patterns between the two groups.

Comprehensive analysis of microRNA-mRNA co-expression in circadian rhythm

To investigate the potential role of microRNA (miRNA) in the regulation of circadian rhythm, we performed microarray-based expression profiling study of both miRNA and mRNA in mouse liver for 48 h at 4-hour intervals. Circadian miRNA-mRNA target pair is defined as the pair both elements of which show circadian expression patterns and the sequence-based target relationship of which can be predicted. Circadian initiators, Clock and Bmal1, showed inversely correlated circadian expression patterns against their corresponding miRNAs, miR-181d and miR-191, targeting them. In contrast, circadian suppressors, Per, Cry, CKIe and Rev-erba, exhibited positively correlated circadian expression patterns to their corresponding miRNAs. Genomic location analysis revealed that intronic region showed higher abundance of cyclic than non-cyclic miRNAs targeting circadian genes while other (i.e., 3'-UTR, exon and intergenic) regions showed no difference. It is suggested that miRNAs are involved in the regulation of peripheral circadian rhythm in mouse liver by modulating Clock:Bmal1 complex. Identifying specific miRNAs and their targets that are critically involved in circadian rhythm will provide a better understanding of the regulation of circadian-clock system.