Identification and characterization of a novel elastase inhibitor from Hirudinaria manillensis / 中国天然药物

A large number of protease inhibitors have been found from leeches, which are essential in various physiological and biological processes. In the curret study, a novel elastase inhibitor was purified and characterized from the leech of Hirudinaria manillensis, which was named HMEI-A. Primary structure analysis showed that HMEI-A belonged to a new family of proteins. HMEI-A exerted inhibitory effects on elastase and showed potent abilities to inhibit elastase with an inhibition constant (K

Protease inhibitor in scorpion (Mesobuthus eupeus) venom prolongs the biological activities of the crude venom / 中国天然药物

It is hypothesized that protease inhibitors play an essential role in survival of venomous animals through protecting peptide/protein toxins from degradation by proteases in their prey or predators. However, the biological function of protease inhibitors in scorpion venoms remains unknown. In the present study, a trypsin inhibitor was purified and characterized from the venom of scorpion Mesobuthus eupeus, which enhanced the biological activities of crude venom components in mice when injected in combination with crude venom. This protease inhibitor, named MeKTT-1, belonged to Kunitz-type toxins subfamily. Native MeKTT-1 selectively inhibited trypsin with a Kivalue of 130 nmol·L(-1). Furthermore, MeKTT-1 was shown to be a thermo-stable peptide. In animal behavioral tests, MeKTT-1 prolonged the pain behavior induced by scorpion crude venom, suggesting that protease inhibitors in scorpion venom inhibited proteases and protect the functionally important peptide/protein toxins from degradation, consequently keeping them active longer. In conclusion, this was the first experimental evidence about the natural existence of serine protease inhibitor in the venom of scorpion Mesobuthus eupeus, which preserved the activity of venom components, suggests that scorpions may use protease inhibitors for survival.

Clinical and experimental study of the therapeutic effect of umbilical cord blood stem cell transplantation on liver failure and heart damage in severe viral hepatitis patients / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate and compare the therapeutic effect of umbilical cord blood stem cell transplantation (UCBSCT) or adult fresh plasma in severe viral hepatitis liver failure with/without heart damage, and to study the effect of UCBSCT on liver lesions in rats.</p><p><b>METHODS</b>83 severe hepatitis patients with/without heart damage were included in the study between January 1994 and June 2003. The patients were treated with UCBSCT or given adult plasma transfusions. The therapeutic effect was evaluated by serial determination of liver function and myocardium enzymes in all patients before and after the treatment. The model of experimental hepatic failure was constructed in SD rats by injecting carbon tetrachloride. Then, the rats were given normal saline, neonate cord blood serum or neonate cord blood stem cells respectively. The expression of human AFP and Alb in SD rat livers was detected by immunohistochemistry; and human special DNA was detected by PCR.</p><p><b>RESULTS</b>The UCBSCT group had much better effects in the improvement of liver function than the adult plasma group had, no matter whether the patients had heart damage or not. Moreover, UCBSCT can decrease heart impairment of the patients. The animal experiment demonstrated that AFP and Alb positive cells were present in the neonate cord blood stem cell group after 21 days and 1 month; human special DNA was detected by PCR in these SD rat livers.</p><p><b>CONCLUSION</b>UCBSCT displayed good therapeutic effects on severe viral hepatitis and improvement of heart injury of the patients. The rat liver immunohistochemistry indicated that neonate cord blood stem cell application can decrease the liver damage and increase hepatocellular regeneration. Human umbilical cord blood stem cells can differentiate into liver cells in acute damaged SD rat livers.</p>