[Inhibition of the TGF-ß/Smad3 signaling pathway by SB431542: A study of the intervention effect of SB431542 on silicotic fibrosis in rats].

Objective: To investigate the intervention effect of SB431542, which inhibits the TGF-ß/Smad3 signaling pathway, on silicotic fibrosis in rats. Methods: A total of 40 specific pathogen-free Sprague-Dawley rats were divided into normal saline control group, model group, SB431542 inhibitor group, and SB431542 inhibitor control group using a random number table, with 10 rats in each group. All rats except those in the normal saline control group were given non-exposed single intratracheal instillation of free silicon dioxide dust suspension 1 mL (50 mg/mL) ; the rats in the SB431542 inhibitor group were given intraperitoneal injection of SB431542 (5 mg/kg) on days 7 and 30 after dust exposure, those in the SB431542 inhibitor control group were given intraperitoneal injection of SB431542 cosolvent (5 mg/kg) on days 7 and 30 after dust exposure, and those in the normal saline control group were given intratracheal instillation of an equal volume of normal saline (5 mg/kg). On day 60 after dust exposure, the paraffin-embedded section of the right upper lobe of lung was collected for HE staining; the left upper lobe of lung was collected to measure the mRNA levels of fibronectin (FN) , collagen type I (COL-I) , and collagen type III (COL-III) by quantitative real-time PCR; the right inferior lobe of lung was collected to measure the protein levels of FN, COL-I, COL-III, phosphorylated Smad3 (p-Smad3) , and Smad3. Results: Compared with the normal saline control group, the model group had nodules with various sizes in lung tissue, with rupture of some alveolar septa, emphysema changes, and pulmonary interstitial fibrosis, as well as significant increases in the mRNA expression of FN, COL-I, and COL-III and the protein expression of FN, COL-I, COL-III, p-Smad3, and Smad3 in lung tissue (P<0.05) . Compared with the SB431542 inhibitor control group, the SB431542 inhibitor group had a relatively complete structure of lung tissue without marked nodules and with a small amount of exudate in alveolar space and the lumen of bronchioles, as well as significant reductions in the mRNA expression of FN, COL-I, and COL-III and the protein expression of FN, COL-I, COL-III, p-Smad3, and Smad3 in lung tissue (P<0.05) . There were no significant differences in the mRNA expression of FN, COL-I, and COL-III and the protein expression of FN, COL-I, COL-III, p-Smad3, and Smad3 between the model group and the SB431542 inhibitor control group (P>0.05) . Conclusion: SB431542 exerts an intervention effect on silicotic fibrosis by blocking the TGF-ß/Smad3 signaling pathway and reducing the expression of the downstream fibrosis factors FN, COL-I, and COL-III.

The relationship between MHC-DRB1 gene second exon polymorphism and hydatidosis resistance of Chinese Merino (Sinkiang Junken type), Kazakh and Duolang sheep.

The present study aimed at detecting the association of ovine major histocompatibility complex class II (Ovar II) DRB1 gene second exon and susceptibility or resistance to hydatidosis in three sheep breeds of Sinkiang. The MHC-DRB1 second exon was amplified by polymerase chain reaction (PCR) from DNA samples of healthy sheep and sheep with hydatidosis. PCR products were characterized by the restriction fragment length polymorphism (RFLP) technique. Five restriction enzymes, Mval, Haelll, Sacl, Sacll, Hin1l, were used, yielding 14 alleles and 31 restriction patterns. Frequencies of patterns Mvalbc, Hin1lab, Sacllab, Haelllde, Haellldf, Haellldd (P < 0.01) in Kazakh sheep, Saclab (P < 0.05) in Duolang sheep, and Haelllab, Haelllce, Haelllde, Haelllee (P < 0.01) in Chinese Merino (Sinkiang Junken type) sheep, were significantly higher in healthy sheep compared with infected sheep. These results indicated a strong association between these patterns and hydatidosis resistance. In contrast, the frequencies of Mvalbb, Saclaa, Hinl lbb, Haelllef (P < 0.01) and Haelllab (P < 0.05) in Kazakh sheep, Saclbb, Haelllae, Hin1lab (P < 0.05), Haelllaa, Haelllbe, Haelllef (P < 0.01) in Duolang sheep, Sacllaa (P < 0.05) and Haelllbd, Hin1lbb, Haelllcf, Haelllef (P < 0.01) in Chinese Merino sheep (Sinkiang Junken type) were significantly lower in healthy sheep compared with infected sheep. This indicated a strong association between these patterns and hydatidosis susceptibility. In addition, sheep with the pattern of Haelllef demonstrated a high hydatidosis susceptibility (P < 0.01) in all three breeds, while sheep with the pattern Haelllde demonstrated significant hydatidosis resistance (P < 0.01) in Kazakh and Chinese Merino sheep (Sinkiang Junken type). These results suggest that the Ovar-DRB1 gene plays a role in resistance to hydatidosis infection in the three sheep breeds.

[Molecular markers linked to dwarf gene Rht3 in wheat].

The dwarf gene Rht3 derived from Tom Thumb variety, a Tibetan wheat of China, is a dominant gene with the insensitivity to gibberellic acid. Rht3 shows to depress alpha-amylase activity and hence enchance the resistance to preharvest sprouting mainly through its effect on the expression of alpha-Amy1. Near isogenic lines with Rht3 and their segregating population were analyzed by PCR and RFLP techonology. In RAPD analysis, out of 310 random primers (10 bp) screened, only three primers of UBC389, OPV-06 and S1060 revealed polymorphisms in NIL from 310 random primers. Fragments S1060(1900) and S1060(2000) amplified by primer S1060 were shown to be linked to Rht3 with a genetic distance 7.1 cM and 9.2 cM. Fifty-three probes specific for short arms of homoeologous group 4 were screened in RFLP analysis. Xpsr584, XksuF8 and Xcdo38 showed polymorphisms between the NIL. The linkage analysis indicateded that Xpsr584 was linked to Rht3 with a genetic distance 8.0 cM.

[Double valve replacement in 400 cases].

From 1985 to 1992, 400 patients received mitral and aortic double valve replacement. Of the patients, 218 were male and 187 female. In early operative days, 6.25% of the patients died. Follow-up study showed that 91.3% of the patients are alive. Perioperative management and improvement of operative technics are detailed.