Effects of soluble transforming growth factor-β type Ⅱ receptor on cardiac functions after myocardial infarction in rats

AIM: To observe the effects of soluble transforming growth factor-β type Ⅱ receptor (sTGFβRⅡ) on cardiac functions after myocardial infarction (MI) in rats. METHODS: MI was induced in Sprague-Dawley (SD) rats by ligating the left anterior descending coronary artery. The rats surviving to the third day after MI were included in the study and randomly divided into MI group, pAd-sTGFβRⅡ group (transfected with recombinant adenovirus vector expressing the extracellular domain gene of TGF-βRⅡ), vector group and sham group. Four weeks later, the heart rate (HR), left ventricular end-diastolic dimension (LVEDD), left ventricular end-systolic dimension (LVESD) and ejection fraction (EF) were evaluated by echocardiograms. The expression of sTGFβRⅡ in myocardial tissues was observed under fluorescence microscope by frozen sectioning, and the expression of typeⅠ and Ⅲ collagens was observed by Sirius red-saturated picric acid staining. The expression of matrix metalloproteinase 9 (MMP-9) at mRNA and protein levels was determined by RT-PCR and immunohistochemical method. The activity of MMP-9 was assayed by gelatin zymography. RESULTS: Compared with sham group, HR, LVEDD, LVESD, typeⅠ and Ⅲ collagen, mRNA and protein of MMP-9, and the activity of MMP-9 increased significantly (P<0.01), and EF decreased (P<0.01) in MI group and vector group. Compared with MI group, EF was increased (P<0.01), but HR, LVEDD, LVESD, typeⅠ and Ⅲ collagen, mRNA and protein expression of MMP-9 and the activity of MMP-9 decreased significantly (P<0.01) in pAd-sTGFβRⅡ group, and all the parameters above were still higher than those in sham group. CONCLUSION: sTGFβRⅡ intervention improves the cardiac functions after MI by inhibiting TGF-β-mediated MMP-9 expression.     

Identification of protein c activator from nine species of Chinese snake venoms

AIM:To determine which species of snake venoms contained protein c activator among 9 species of Chinese snake venoms. METHODS: Anticoagulant activity was examined by activated partial thromboplastin time (APTT) assay,and amidolytic activity was measured with activated protein c (APC) specific chromogenic peptide substrate-chromozy APC. RESULTS: Among 9 species of Chinese snake venoms,Trimeresurus mucrosquamatus venom and Agkistrodon halys venom were not only able to generate amidolytic activity from purified human PC, but also prolonged APTT strongly even at such a concentration as 1.5 mg/L. CONCLUSION:Trimeresurus mucrosquamatus venom and Agkistrodon halys venom contain protein c activator which activating human plasma PC into APC.     

Effects of bilberry anthocyanins on MMP2 and collagen I in human fetal scleral fibroblast in vitro

AIM:To investigate the effects of bilberry anthocyanins on matrix metalloproteinase 2 (MMP2) and collagen type I (collagen I) expression in human fetal scleral fibroblasts (HFSF) in vitro and to provide experimental data for the prevention and treatment of myopia by bilberry anthocyanins. METHODS:HFSF were treated with bilberry anthocyanins at different concentrations (0, 10^-6, 10^-5, 10^-4, 10^-3, 10^-2, 10^-1 and 1 g/L). The effects of bilberry anthocyanins on the viability of HFSF for different time (6 h, 8 h, 12 h, 24 h and 48 h) were measured by MTT assay. The cell cycle distribution and apoptosis of HFSF with highest viability (10^-1 g/L bilberry anthocyanins for 12 h) were analyzed by flow cytometry. The mRNA expression of MMP2, COL1A1 and COL1A2 in the HFSF was detected by RT-qPCR. The protein expression of MMP2 and collagen I was determined by Western blot. RESULTS:The cell viability was the highest after treatment with bilberry anthocyanins at a concentration of 10^-1 g/L for 12 h. Compared with blank control group, 10^-1 g/L bilberry anthocyanin group showed increased cell numbers in S and G₂ phases (P<0.05), but no significant difference of the apoptotic rate was observed. The mRNA expression of MMP2 was decreased (P<0.05), and that of COL1A1 was increased (P<0.05). No significant difference of COL1A2 expression was seen. The protein expression of MMP2 was decreased (P<0.05), and collagen I protein was increased (P<0.05). CONCLUSION:Bilberry anthocyanins inhibit the expression of MMP2 and increase the expression of collagen I in the HFSF.     

Hemolytic anemia,spherocytosis, and thrombocytopenia associated with honey bee envenomation in a dog

This case report describes a massive honey bee envenomation in a 14‐month‐old male Belgian Malinois dog from St. Kitts, West Indies. Acute and delayed onsets of hemolytic anemia, echinocytosis, spherocytosis, thrombocytopenia, hemoglobinemia, and hemoglobinuria developed following envenomation. The dog recovered after treatment with glucocorticoids and supportive therapy. Spherocytosis, hemolysis, and thrombocytopenia in patients with massive bee envenomation are likely due to the direct toxic effects of the primary components of bee venom, melittin and phospholipase A₂ (PLA₂). Mellitin causes hemolysis by forming large pores in erythrocytes resulting in leakage of hemoglobin and also causes spectrin stiffening and resultant echinocyte and spherocyte formation. Melittin also stimulates PLA₂, a hydrolase that causes echinocytosis and spherocytosis, in vivo and in vitro, and mitochondrial breakdown in platelets. However, delayed manifestations could be attributed to immune‐mediated mechanisms from the generation of antibodies against damaged erythrocytes and platelet membrane proteins.     

蛇毒神经毒素研究进展

我国的蛇类资源丰富,从理论意义和长远的经济效益考虑,蛇毒的研究是一个很有价值的方向。近年来,随着蛇毒神经毒素结构的确定、理化性质和药理性质的测定及蛇毒神经毒素的临床应用,其在镇痛功能方面表现出的维持时间长、效价高、无耐受性和无成瘾性等特点而倍受关注。蛇毒具有广泛的生物学活性,论文就蛇毒组分中近年来研究较为深入的神经毒素的结构、理化性质、药理作用及其应用等方面进行了综述。     

Clonal relatedness of Salmonella isolates associated with invasive infections in captive and wild-caught rattlesnakes

This study examines the serotype distribution and clonal relatedness among Salmonella isolates obtained from healthy and diseased snakes. Isolates from extraintestinal body sites were obtained through routine diagnostic lab submissions from snakes in two facilities that had experienced a high prevalence of osteomyelitis in Crotalus species. Gastrointestinal isolates were predominantly from fecal samples collected from healthy snakes of both crotalid and non-crotalid species in one facility. PFGE macrorestriction analysis of Salmonella isolates confirmed the clonal and species-restricted nature of Salmonella serotype IIIa 56: z4, z23: - in one facility. Fourteen of 15 isolates from suspected osteomyelitis lesions in wild-caught snakes at the second facility were also from Salmonella subgroup IIIa (serotype IIIa 18: z4, z23: -) and appeared to be closely related by PFGE. Evaluation of a PCR assay for the spvC gene in 209 isolates demonstrated that this method consistently distinguished isolates of subgroup IIIa from those of subgroup IIIb. The data presented establish that Salmonella of subgroup IIIb are abundant and regularly associated with gastrointestinal shedding in snakes but that Salmonella in subgroup IIIa disproportionately cause infections in bone or other extraintestinal sites.     

电取蜂毒对中华蜜蜂寿命的影响

采用QF—1型电子取毒仪,分别电刺激3～27日龄的中蜂工蜂5分钟,结果3和6日龄的工蜂寿命缩短差异不显著(P>0.05);9、12、15、18日龄的工蜂寿命缩短2.75～4.59天,差异显著(P<0.05);21、24、27日龄的工蜂寿命缩短4.50～4.75天,差异极显著(P<0.01)。     

Effects of platelet rich plasma and acellular bone marrow on gene expression patterns and DNA content of equine suspensory ligament explant cultures

REASONS FOR PERFORMING STUDY: Suspensory ligament (SL) desmitis is a common source of lameness. The results of this study will determine if blood-derived products stimulate SL matrix synthesis and have potential as regenerative therapies for SL desmitis OBJECTIVES: To determine if various blood-based biological products including plasma, blood, PRP, platelet poor plasma (PPP) and ABM aspirate stimulates anabolic and/or catabolic pathways in suspensory ligaments (SL). METHODS: The body of the SL was harvested from 6 horses and used to establish explant cultures. Explants were cultured in plasma, blood, PRP, PPP or ABM at concentrations of 10, 50 or 100%. Anabolic responses were assessed by use of quantitative PCR for collagens type I and III, cartilage oligomeric matrix protein (COMP) and decorin. Total DNA and collagen protein content were also measured. Catabolic reactions were measured by quantitative PCR for matrix metalloproteinases 3 and 13 (MMP-3, MMP-13). Results: Acellular bone marrow aspirate at 100% stimulated decorin and COMP mRNA synthesis more than all other treatments at all concentrations. No treatment at any concentration stimulated the catabolic gene MMP-13; only 50% ABM stimulated MMP-13 mRNA expression. CONCLUSIONS: Acellular bone marrow is indicated, and might be preferred to plasma, blood or PPP, as a blood-based biological source for SL tissue regenerative therapy. Long-term, placebo controlled case studies are indicated to determine if ABM aids in recovery from SL desmitis. POTENTIAL RELEVANCE: Bone marrow aspirate is an autogenous, readily available biological source for SL regenerative therapy where the aim is to stimulate matrix synthesis.