Stimulation of Airway and Intestinal Mucosal Secretion by Natural Coumarin CFTR Activators.

Mutations of cystic fibrosis (CF) transmembrane conductance regulator (CFTR) cause lethal hereditary disease CF that involves extensive destruction and dysfunction of serous epithelium. Possible pharmacological therapy includes correction of defective intracellular processing and abnormal channel gating. In a previous study, we identified five natural coumarin potentiators of ΔF508-CFTR including osthole, imperatorin, isopsoralen, praeruptorin A, and scoparone. The present study was designed to determine the activity of these coumarine compounds on CFTR activity in animal tissues as a primary evaluation of their therapeutic potential. In the present study, we analyzed the affinity of these coumarin potentiators in activating wild-type CFTR and found that they are all potent activators. Osthole showed the highest affinity with K(d) values <50 nmol/L as determined by Ussing chamber short-circuit current assay. Stimulation of rat colonic mucosal secretion by osthole was tested by the Ussing chamber short-circuit current assay. Osthole reached maximal activation of colonic Cl(-) secretion at 5 µmol/L. Stimulation of mouse tracheal mucosal secretion was analyzed by optical measurement of single gland secretion. Fluid secretion rate of tracheal single submucosal gland stimulated by osthole at 10 µmol/L was three-fold more rapid than that in negative control. In both cases the stimulated secretions were fully abolished by CFTR(inh)-172. In conclusion, the effective stimulation of Cl(-) and fluid secretion in colonic and tracheal mucosa by osthole suggested the therapeutic potential of natural coumarin compounds for the treatment of CF and other CFTR-related diseases.

[Investigation in vivo of effect of ultrasound-mediated microbubble destruction on entrance of feridex into the aortal wall].

OBJECTIVE: To explore feasibility for entrance of the contrast agent Sonovue and Feridex into the aortal wall. METHODS: 17 male Japanese giant ears rabbits (common grade), including 11 atherosclerosis (AS) animal models fed with food containing high-content lipid and normal animals fed with common food as control. Respectively, 10 animals in the AS group and 6 animals in the normal group were selected in a random way to undergo ultrasound-mediated microbubble destruction (UMMD) and no ultrasound-mediated microbubble destruction (-UMMD) half and half. One animal was administrated with double doses of Feridex. After general anesthesia, MR plain scan and intravenous injection of Feridex 100 micromol Fe/kg, immediately ultrasound focused on the front wall of the aortic arch, which underwent UMMD at the pressure of 3.5 Mpa with MI1.2 while 10 ml solution (Sonovue + normal saline)was injected intravenously at the speed of 0.5 ml/min FOR 20 min. 3T magnetic resonance (MR) was performed with a moderately T2* weighted gradient sequence. Enhanced scan were performed for 1 h, 24 h, 48 h, 72 h and after killing the animal. then the specimen were delivered to conduct optical and electronic microscope examination. Variance test for the re-measured data was adopted to verify the data obtained in every group. RESULTS: The effect of UMMD group on SPIO particles entrance into the aortal wall is of marked significance (P = 0.0004) statistically. The effect of UMMD on distribution in the vessel wall is of statistical significance (P = 0.01), more particles in the dventitia. Gas or microbubbles were found to enter into the intima, media of the aorta, and verified by Oil Red O staining. After staining the findings of iron particle in the cell and out of the cell are different. CONCLUSIONS: UMMD may facilitate entrance of those SPIO particles with a bigger diameter and microbubbles into the aortal wall. This discovery may provide a new solution for penetration of complex macromolecule probes and gene-carried drug through the tunica intima of the aorta.

[Sperm mtDNA content and mtDNA4977bp deletion in normal and leukocytospermia men].

OBJECTIVE: To determine the sperm mtDNA content, mtDNA4977bp deletion and ROS in the seminal plasma of normal and leukocytospermia men, and to investigate the correlation of the changes of sperm mtDNA with the increase of leukocytes and reactive oxgygen species (ROS) in the seminal plasma. METHODS: Seventy-eight semen samples from leukocytospermia patients and 31 from healthy donors were divided into 3 layers, supernatant fluid, 30% sperm and 80% sperm, by Percoll gradient centrifugation, their sperm mtDNA content and mtDNA4977bp deletion quantitatively analyzed by real-time PCR, and the level of ROS determined by flow cytometry. RESULTS: The ROS in the seminal plasma and the sperm mtDNA contents of the three layers were all significantly higher in the leukocytospermia group than in the healthy control (P < 0.01). In the supernatant fluid and 80% layers, mtDNA4977bp deletion showed no obvious difference between the control and the leukocytospermia group, but was significantly higher in the 30% layer of the latter (P < 0.01). The ROS level was found positively correlated with the mtDNA content in the 30% (r = 0.347, P < 0.01) and the 80% layer (r = 0.456, P < 0.01), but not in the supernatant layer. CONCLUSION: The increase of leukocytes and ROS may be one of the causes of the enhanced sperm mtDNA content, but has no significant impact on the mtDNA4977bp deletion.

[An approach to male infertility from economic sociology].

OBJECTIVE: To study the psychology of infertility patients from the perspective of economic sociology so as to prevent the patients from medical frauds in seeking medical treatment. METHOD: We investigated 902 infertility patients of the Third Hospital of Peking University from September 2005 to January 2006 using a randomized questionnaire. RESULTS: Of the total number, 84.4% had education below college level; the majority had a low monthly family income, 36.6% below Y1,000, 19.7% from Y1,000 to Y2,000, 16.5% from Y2,000 to Y3,000, 7.8% from Y3,000 to Y4,000 and 19.4% above Y4,000; 88.7% had a strong desire for a child; 60.3% were psychologically stressed. As for the advertisements for the treatment of infertility, 50.2% of the patients disbelieved them, 6.2% wanted to have a try and about 43.6% accepted them to be true. Regarding the treatment in individual hospitals, 55.2% disbelieved in it, 5.8% wanted to try it and about 39.0% believed in it. CONCLUSION: Infertility patients of low economic status usually have a lower educational level but a higher desire for children, and therefore are more likely to be the victims of medical frauds and more psychologically stressed. It calls for our attention how to provide them with medical help.

Suppression of gastric cancer growth by adenovirus-mediated transfer of the PTEN gene.

AIM: To investigate the tumor-suppressive effect of the phosphatase and tensin homologue deleted from chromosome (PTEN) in human gastric cancer cells that were wild type for PTEN. METHODS: Adenoviruses expressing PTEN or luciferase as a control were introduced into gastric cancer cells. The effect of exogenous PTEN gene on the growth and apoptosis of gastric cancer cells that are wtPTEN were examined in vitro and in vivo. RESULTS: Adenovirus-mediated transfer of PTEN (Ad-PTEN) suppressed cell growth and induced apoptosis significantly in gastric cancer cells (MGC-803, SGC-7901) carrying wtPTEN in comparison with that in normal gastric epithelial cells (GES-1) carrying wtPTEN. This suppression was induced through downregulation of the Akt/PKB pathway, dephosphorylation of focal adhesion kinase and mitogen-activated protein kinase and cell-cycle arrest at the G2/M phase but not at the G1 phase. Furthermore, treatment of human gastric tumor xenografts (MGC-803, SGC-7901) with Ad-PTEN resulted in a significant (P<0.01) suppression of tumor growth. CONCLUSION: These results indicate a significant tumor-suppressive effect of Ad-PTEN against human gastric cancer cells. Thus, Ad-PTEN may be used as a potential therapeutic strategy for treatment of gastric cancers.