Molecular cloning and functional analysis of HnSaratin from Hirudo nipponia.

In order to finish a bloodmeal successfully, hematophagous organisms often stored a variety of anticoagulant proteins in their salivary glands, such as proteins that inhibit platelet aggregation. When they ingest a bloodmeal, these proteins are injected into the host to prevent the blood from clotting. As one of the origins of leeches used in traditional Chinese medicine, H. nipponia was proved to be clinically effective in treatment of cardiovascular and cerebrovascular diseases. This study cloned the sequence of HnSaratin cDNA derived from salivary glands of H. nipponia. The sequence contains an open reading frame of 387 bp, encoding a protein of 128 amino acids containing a signal peptide of 21 amino acids. After removal of the signal peptide, the molecular mass of mature HnSaratin was 12.37 kDa, with a theoretical isoelectric point (pI) of 3.89. The N-terminal of mature HnSaratin was folded into a globular structure, in which 3 disulfide bonds, a ßßαßßß topology and 2 Glu residues that binds collagenous Lys2 were located, and the C-terminal formed a flexible region. The fusion HnSaratin protein was obtained by a prokaryotic expression system. The protein showed anti-platelet aggregation activity, and was observed to prevent blood clotting in rats. The significant high expression of HnSaratin mRNA in salivary glands was induced by bloodmeal ingestion of H. nipponia. Briefly, our work provides theoretical basis for further development and utilization of H. nipponia.

Efficacy of mouth opening exercises in treating trismus after maxillectomy.

BACKGROUND: Patients with maxillary tumor often suffer from trismus after maxillectomy, which could turn out to be a permanent sequela without proper intervention. In this study, the efficacy of mouth opening exercises in preventing and treating trismus was observed in patients with maxillary tumor early after their operations. At the same time, radiotherapy as an influencing factor for the mouth opening exercises was evaluated. METHODS: In this study, 22 patients with maxillary oncology began their mouth opening exercises at an early stage (1-2 weeks) after maxillectomy. They were divided into two groups based on the principle of voluntariness: 11 patients in group 1 chose TheraBites as their instruments of mouth opening exercises, and the other 11 in group 2 chose stacked tongue depressors to help their exercises. All participants were trained to exercise 3-5 times a day, 30-40 oscillations at one time, with a 2-second pause at their maximum possible mouth open position. The maximal interincisor distances (MID) of patients were measured and recorded by a single investigator every week after the beginning of the mouth opening exercises. Medical information and the responses of patients were also recorded. Initial and final MIDs were calculated by SPSS 13.0. RESULTS: The changes of the mouth aperture every week during exercises in both groups were described in figures, and there were statistical increases in the final MIDs compared with the initial ones. However, no significant differences were achieved between groups 1 and 2 (P > 0.05). Radiotherapy seemed to have no negative impact on the mouth opening results during the exercises. CONCLUSION: Physical mouth opening exercises should be executed early after maxillectomy for the prevention and treatment of trismus, especially for those who had radiotherapy as part of antitumor treatments.