Chromatin three-dimensional genome structure plays a key role in cell function and gene regulation. Single-cell Hi-C techniques can capture genomic structure information at the cellular level, which provides an opportunity to study changes in genomic structure between different cell types. Recently, some excellent computational methods have been developed for single-cell Hi-C data analysis. In this paper, the available methods for single-cell Hi-C data analysis were first reviewed, including preprocessing of single-cell Hi-C data, multi-scale structure recognition based on single-cell Hi-C data, bulk-like Hi-C contact matrix generation based on single-cell Hi-C data sets, pseudo-time series analysis, and cell classification. Then the application of single-cell Hi-C data in cell differentiation and structural variation was described. Finally, the future development direction of single-cell Hi-C data analysis was also prospected.
ObjectiveTo investigate the effectiveness of the Evans lateral lengthening calcaneal osteotomy (E-LLCOT) in treatment of talocalcaneal coalition (TCC) with hindfoot valgus deformity.MethodsBetween January 2014 and October 2017, 10 patients (13 feet) of TCC with hindfoot valgus deformities underwent E-LLCOTs. There were 6 males (8 feet) and 4 females (5 feet) with an age of 13-18 years (mean, 15.8 years). The disease duration was 10-14 months (mean, 11.5 months). The foot deformity was characterized by hindfoot valgus, forefoot abduction, and collapse of the medial arch. Pain site was the tarsal sinus in 4 feet, TCC in 5 feet, and ankle joint in 4 feet. There were tightness of the gastrocnemius in 3 cases (4 feet) and Achilles tendon in 7 cases (9 feet) on Silverskiold test. The preoperative American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score was 46.54±9.08 and visual analogue scale (VAS) score was 6.54±0.88 after walking 1 kilometer. The AOFAS ankle-hindfoot score and VAS score were adopted to evaluate the postoperative function of the foot. The talar-first metatarsal angle (T1MT), talonavicular coverage angle (TCA), talar-horizontal angle (TH), calcaneal pitch angle (CP), and heel valgus angle (HV) were measured after operation.ResultsAll incisions healed by first intention. All patients were followed up 12-30 months (mean, 18 months). At last follow-up, the AOFAS ankle-hindfoot score and VAS score were 90.70±6.75 and 1.85±0.90, respectively, showing significant differences when compared with preoperative scores (t=−23.380, P=0.000; t=35.218, P=0.000). X-ray films showed that the osteotomy healed at 2-4 months (mean, 3 months) after operation. At last follow-up, the T1MT, TCA, TH, and HV were significantly lower than preoperative ones (P<0.05), and the CP was significantly higher than preoperative one (P<0.05). During the follow-up, the pain did not relieve obviously in 1 patient (1 foot), and the cutaneous branch of the sural nerve injured in 1 patient (1 foot).ConclusionFor TCC with severe hindfoot valgus deformity, E-LLCOT can effectively correct deformity and relieve pain.