Objective To evaluate the long-term results of partial internal sphincterectomy for the treatment of internal anal sphincter achalasia in childhood. Methods The clinical,radiographic,manometrical and histochemical data of 6 cases were reviewed retrospectively. All patients had received partial internal sphincterectomy and were followed-up for 2 to 8 years. Results All patients presented with severe constipation with or without soiling. No stenosis zone of intestine could be noted in 3 patients by barium enema examination. The rectoanal inhibition reflex on rectal balloon inflation was absent in all patients. The normal acetylcholinesterase activity on rectal biopsies was demonstrated by histochemical staining. Ganglion cells within internal anal sphincter was noted in all cases. On follow-up,all patients regained regular bowel habits and are not on any laxatives. Conclusion The long term results of partial internal sphincterectomy for the treatment of internal anal sphincter achalasia in childhood are satisfactory.

CCCTC-binding factor (CTCF) is a zinc-finger protein, serving an important part in the genome architecture as well as some biochemical processes. Over 70,000 CTCF binding DNA sites have been detected genome-wide, and most anchors of chromatin loops are demarcated with the CTCF binding. Various protein or RNA molecules interact with DNA-bound CTCF to conduct different biological functions, and potentially the interfaces between CTCF and its cofactors can be targets for drug development. Here we identify the effective region of CTCF in DNA recognition, which defines the exposed CTCF surface feature for the interaction of cofactors. While the zinc-finger region contributes the most in DNA association, its binding affinity varies based on different DNA sequences. To investigate the effectiveness of individual zinc-fingers, the key residues are mutated to inactivate the DNA binding ability, while the finger configuration and the spacing between fingers are preserved. The strategy is proved to be successful, while clear differences are observed in the DNA binding affinities among the 11 finger mutants and the result is consistent to previous studies in general. With the help of inactivated finger mutants, we identify the ineffective fingers and the dominant effective fingers, which form distinctive patterns on different DNA targets.