Clinical Effects of Ultrasound-Guided Acupotomy in Knee Osteoarthritis Treatment.

The protocol presented here demonstrates the operation method of ultrasound-guided acupotomy for knee osteoarthritis (KOA), including patient recruitment, preoperative preparation, manual operation, and postoperative care. The purpose of this protocol is to relieve pain and improve knee function in patients with KOA. A total of 60 patients with KOA admitted between June 2022 and June 2023 were treated with ultrasound-guided acupotomy. Pathological changes and knee function scores were compared before and after the treatment. After 1 week of treatment, the synovial thickness of the suprapatellar bursae was significantly lesser than before treatment (p < 0.05), the Hospital for Special Surgery Knee Score (HSS) was significantly higher than before treatment (p < 0.05), the Visual analogue scale (VAS) was significantly lower than those of the control group (p < 0.05) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were significantly lower than those of the control group (p < 0.05). Therefore, ultrasound-guided acupotomy for the treatment of KOA can reduce synovial thickness, relieve pain, improve knee joint function, and have a remarkable curative effect.

[Preliminary evaluation of promoter regions of four Schistosoma japonicum genes for expressing a luciferase reporter].

OBJECTIVE: To evaluate the relevant promoter regions of four Schistosoma japonicum genes for expressing a luciferase reporter. METHODS: The polymerase chain reaction (PCR) was used to amplify the promoter regions of four S. japonicum genes and then each PCR product was cloned into a pGlu-Basic vector according to the standard molecular procedures. These recombinant plasmids were either transfected into human HEK293 cells by using lipofectamine or introduced into cultured schistosomes by electroporation. Then, the luciferase activities were measured by using a dual luciferase reporter system in a luminometer. RESULTS: Each promoter region of four S. japonicum genes was obtained and the corresponding recombinant vector containing the promoter region was successfully constructed. The transfection of the recombinant plasmids into the human HEK293 cells and cultured schistosomes resulted in a significant elevation of the luciferase reporter activity. CONCLUSIONS: The promoter regions of four S. japonicum genes are obtained and the luciferase reporter genes driven by the four promoter regions are preliminarily evaluated. The study provides a foundation for the usage of these promoters for genetic manipulation in S. japonicum.

[Association between 1019C/T polymorphism of Connexin 37 gene and restenosis after coronary stenting].

OBJECTIVE: To assess the association between 1019C/T polymorphism of Connexin 37 (CX37) gene and susceptibility to restenosis after percutaneous coronary intervention (PCI) in ethnic Han Chinese patients from Wuxi. METHODS: Five hundred and thirty-two patients with coronary artery disease (CAD) who had undergone PCI underwent coronary angiography (CAG) in 3 months, and were divided into in stent restenosis (ISR) group (n=67) and no instent restenosis (NISR) group (n=465). Five hundred and one healthy individuals have served as the control group. All cases were genotyped with DNA sequencing. RESULTS: Compared with healthy controls, the frequency of CX37 C allele was higher in CAD patients (57.05% vs. 41.32%, P< 0.01). The frequency of C carries (CC+TC) was 79.32% in CAD patients, against 65.47% in healthy controls (P<0.01). The risk for CAD was significantly increased in carriers of C allele (CC+TC) compared with TT homozygotes (OR=2.03, 95% CI: 1.53-2.80). Stratified analysis has indicated a significant difference in the frequency of C allele carriers between both male and female CAD patients and healthy controls (79.63% vs. 72.45%, P=0.02; 78.00% vs. 51.50%, P< 0.01). For both genders, carriers of C allele had a higher risk for CAD compared with TT homozygotes (males: OR=1.48, 95% CI: 1.06-2.09; females: OR=3.34, 95% CI: 1.90-5.86). Compared with NISR group, the frequency of CX37 C allele and C carries (CC+TC) were significantly higher in ISR group (72.39% vs. 54.84%, P< 0.01; 89.55% vs. 77.85%, P=0.027). Compared with TT homozygotes, the risk for restenosis has significantly increased in carriers of C allele (CC+TC) (OR=2.44, 95% CI: 1.08-5.50). Stratified analysis also suggested that the frequency of C carriers was significantly higher in male ISR group compared with male NISR group (92. 86% vs. 77.66%, P=0.008). The risk for restenosis has increased by nearly four fold in carriers of C allele (CC+TC) compared with TT homozygotes (95% CI: 1.32-10.64). However, for female patients, no significant difference was detected in the ISR risk between carriers of CC+TC type and TT homozygotes (P=0.655). CONCLUSION: The C allele of 1019C/T polymorphism in the CX37 gene is associated with susceptibility to CAD as well as restenosis after coronary stenting in male patients from Wuxi.

Association between C1019T polymorphism of the connexin37 gene and coronary heart disease in patients with in-stent restenosis.

Studies have shown that a C1019T polymorphism of the gene encoding the gap junction protein connexin37 is associated with coronary artery disease (CAD). The aim of the present study was to explore the association between the C1019T polymorphism in the connexin37 gene and CAD patients with in-stent restenosis (ISR). A total of 532 patients who had undergone coronary stenting and coronary angiography at least three months after the procedure were divided according to a clinical diagnosis standard into two groups which were ISR (n=67) and no in-stent restenosis (NISR; n=465) groups. A further 501 healthy individuals were controls. The subjects were genotyped by DNA sequencing. The results demonstrated the following: i) connexin37 gene 1019 sites in the population were distributed by polymorphism into three genetic types (CC, TC and TT types). The distribution frequency of the healthy control, ISR and NISR groups conformed to the Hardy-Weinberg genetic balance rule; ii) in comparison with the healthy controls, the frequency of the connexin37 C allele was higher in the CAD patients (57.05% vs. 41.32%; OR, 1.89; 95% CI, 1.58-2.25; P<0.01). The frequency of the C carriers (CC+TC) was 65.47% in the healthy controls, vs. 79.32% in CAD patients (P<0.01). The CAD risk was significantly increased in the carriers of the C allele (CC+TC) compared with TT homozygotes (OR, 2.03; 95% CI, 1.53-2.80; P<0.01). Stratified analysis demonstrated that a significant difference existed in the frequency of C carriers between the male CAD patients and healthy controls (79.63% vs. 72.45%; OR, 1.48; 95% CI, 1.06-2.09, P=0.02), as well as in the female CAD patients (78.00% vs. 51.50%; OR, 3.34; 95% CI, 1.90-5.86; P<0.01). In the female and male CAD patients, the frequency of the connexin37 C allele was higher than in the healthy controls (male: χ(2)=12.67, P<0.01; female: χ(2)=50.20, P<0.01); iii) compared with the NISR group, the frequencies of the connexin37 C allele and C carriers (CC+TC) were significantly higher in the ISR group (frequency of C allele: 72.39% vs. 54.84%; P<0.01; frequency of C carriers: 89.55% vs. 77.85%; P=0.03). Compared with TT homozygotes, the restenosis risk was significantly increased in the carriers of the C allele (CC+TC; OR, 2.44; 95% CI, 1.08-5.50). Subsequent stratified analysis revealed that the frequency of the C allele was significantly higher in the male ISR group than in the male NISR group (78.57% vs. 52.66%; OR, 3.30; 95% CI, 2.05-5.29; P<0.01). The restenosis risk was ∼four-fold higher in the C carriers (CC+TC) than in the TT homozygotes (OR, 3.74; 95% CI, 1.32-10.64). However in the female population, there was no difference in the ISR risk between the carriers of the C allele (CC+TC) and the TT homozygotes (P=0.70). In summary, the C allele of the connexin37 gene is not only is associated with the susceptibility to CAD, but also associated with restenosis following coronary stenting in the population studied herein, particularly the male population.

Association between C1019T polymorphism in the connexin 37 gene and Helicobacter pylori infection in patients with gastric cancer.

OBJECTIVE: To investigate the association between the connexin 37 C1019T polymorphism and Helicobacter pylori infection in patients with gastric cancer. METHODS: 388 patients with gastric cancer (GC), 204 with chronic superficial gastritis (CSG) were studied. H. pylori was detected by gastric mucosal biopsies biopsy dyeing method. Connexin 37 gene polymorphism 1019 site genotypes were determined by gene sequencing technology. Genotypes and alleles frequencies were compared. RESULTS: (1) Connexin37 gene 1019 site distribution frequency (CC type, TC type, TT type) in the CSG group was 18.1%, 45.1% and 36.8%; in the stomach cancer group it was 35.1%, 45.9% and 19.%, conforming to the Hardy-Weinberg euilibrium. (2) In comparison with CSG group, the frequency of Connexin37 C allele was higher in the gastric cancer group (58.0% vs 40.7%, OR=2.01, 95%CI=1.58-2.57, P<0.01). The prevalence of gastric cancer risk was significantly increased in the carriers of C allele (CC+TC) than in TT homozygote (OR=2.47, 5%CI=1.68-3.610. (3) Gastric cancer patients complicated with Hp infection 211 cases, gastric cancer group of the male patients with HP positive patients with 187 cases, 40 cases of female patients with negative patients, 24 cases were HP positive, negative in 137 cases, control group male patients, 28 cases were Hp positive, negative in 95 patients, female patients with Hp positive 6 cases, 75 cases were negative. On hierarchical analysis, the male group OR value was 15.9 (95%CI to 9.22-27.3), and the female OR was 2.19 (95%CI 0.88-5.59), indicating a greater contribution in males (P<0.01). After elimination of gender effects, positive HP and gastric cancer were closely related (OR 8.82, 95% CI: 5.45-14.3). (4) The distribution frequency of C allele in patients with Hp infection was much higher than that in Hp negative cases in the GC group (64.5% vs 47.0%, OR=2.05, 95%CI=1.54-2.74, P<0.01). Compared with TT homozygotes, (CC+TC) genotype prevalence of gastric cancer risk increased significantly (OR=2.96, 5%CI=1.76-2.99). CONCLUSION: The T allele in the connexin37 gene might not only be associated with gastric cancer but also with H. pylori infection.

Molecular mechanisms of diabetic coronary dysfunction due to large conductance Ca2⁺-activated K⁺ channel impairment.

BACKGROUND: Diabetes mellitus is associated with coronary dysfunction, contributing to a 2- to 4-fold increase in the risk of coronary heart diseases. The mechanisms by which diabetes induces vasculopathy involve endothelial-dependent and -independent vascular dysfunction in both type 1 and type 2 diabetes mellitus. The purpose of this study is to determine the role of vascular large conductance Ca(2+)-activated K(+) (BK) channel activities in coronary dysfunction in streptozotocin-induced diabetic rats. METHODS: Using videomicroscopy, immunoblotting, fluorescent assay and patch clamp techniques, we investigated the coronary BK channel activities and BK channel-mediated coronary vasoreactivity in streptozotocin-induced diabetic rats. RESULTS: BK currents (defined as the iberiotoxin-sensitive K(+) component) contribute (65 ± 4)% of the total K(+) currents in freshly isolated coronary smooth muscle cells and > 50% of the contraction of the inner diameter of coronary arteries from normal rats. However, BK current density is remarkably reduced in coronary smooth muscle cells of streptozotocin-induced diabetic rats, leading to an increase in coronary artery tension. BK channel activity in response to free Ca(2+) is impaired in diabetic rats. Moreover, cytoplasmic application of DHS-1 (a specific BK channel b(1) subunit activator) robustly enhanced the open probability of BK channels in coronary smooth muscle cells of normal rats. In diabetic rats, the DHS-1 effect was diminished in the presence of 200 nmol/L Ca(2+) and was significantly attenuated in the presence of high free calcium concentration, i.e., 1 mmol/L Ca(2+). Immunoblotting experiments confirmed that there was a 2-fold decrease in BK-b(1) protein expression in diabetic vessels, without altering the BK channel α-subunit expression. Although the cytosolic Ca(2+) concentration of coronary arterial smooth muscle cells was increased from (103 ± 23) nmol/L (n = 5) of control rats to (193 ± 22) nmol/L (n = 6, P < 0.05) of STZ-induced diabetic rats, reduced BK-b(1) expression made these channels less sensitive to intracellular Ca(2+), which in turn led to enhanced smooth muscle contraction. CONCLUSIONS: Our results indicated that BK channels are the key determinant of coronary arterial tone. Impaired BK channel function in diabetes mellitus is associated with down-regulation of BK-b(1) expression and reduction of the b(1)-mediated BK channel activation in diabetic vessels.

[Mechanism related to docosahexaenoic acid induced large conductance calcium-activated potassium channel currents increase in coronary smooth muscle cells].

OBJECTIVE: To investigate the mechanism of enhanced large conductance calcium-activated potassium channel currents (BK) in coronary smooth muscle cells (SMCs) by docosahexaenoic acid (DHA). METHODS: Coronary SMCs were isolated by enzyme digestion. Potassium channels in coronary SMCs were identified by applications of different potassium blockers. Effects of DHA and its metabolite 16, 17-epoxydocosapentaenoic acid (16, 17-EDP) on BK channels in the absence and presence of cytochrome P450 epoxygenase inhibitor SKF525A were studied by patch clamp in whole-cell configuration. RESULTS: BK channels were widely distributed in SMCs, and BK currents in normal SMCs accounted for (64.2 ± 2.7)% of total potassium currents (n = 20). DHA could activate BK channels, and its 50% effective concentration (EC(50)) was (0.23 ± 0.03) µmol/L, however, the effect of DHA on BK channels was abolished after SMCs were incubated with cytochrome P450 epoxygenase inhibitor SKF525A. 16, 17-EDP, a metabolite of DHA, could reproduce the effects of DHA on BK channels, and its EC(50) was (19.7 ± 2.8) nmol/L. CONCLUSION: DHA and metabolites can activate BK channels and dilate coronary arteries through activating cytochrome P450 epoxygenase pathway.

[Cathepsin B promoted the apoptosis of vascular smooth muscle cells as induced by tumor necrosis factor-α].

OBJECTIVE: To establish the cathepsin B over-expression group and cathepsin B gene-silencing group so as to investigate whether cathepsin B was capable of promoting the apoptosis of VSMC (vascular smooth muscle cell) induced by TNF-α/act D. METHODS: Human aortic smooth muscle cell (HA-VSMC) was transfected with pcDNA3.1-cathepsin B and pSilencer2.1-cathepsin B plasmids by lipofection to establish the over-expression and gene-silencing groups. Through TNF-α induced apoptosis, the cell viability was observed by MTT assay, morphological observation and assays of apoptotic proteins as indicators of apoptosis. RESULTS: The cathepsin B over-expression and gene-silencing group were successfully established. MTT assay showed no significant difference between the transfected cell and blank control. After the intervention of TNF-α, the HA-VSMC viability decreased significantly. As compared with control group, the over-expression group significantly decreased (9.98% ± 1.04% vs 14.60% ± 1.34%). As compared with the over-expression group, the E64d and CA-074ME groups (18.23% ± 1.05%, 17.40% ± 1.03%) increased significantly while the silent group (21.30% ± 2.37%) significantly increased. The analysis of acridine orange/ethidium bromide staining showed similar results. Western blot showed the Bcl-2 protein were significantly higher in the silent group than that in the control group. And the over-expression group was significantly lower than the control group. The E64d and CA-074ME groups were significantly higher than that in the over-expression group. But the Bax protein level had no significant difference among all groups. CONCLUSION: The over-expression of cathepsin B promotes TNF-α-induced VSMC apoptosis while Cathepsin B gene silencing and the addition of cathepsin inhibitor in over-expression group inhibit the TNF-α induced VSMC apoptosis.

[Value of detecting in-stent restenosis by dual source coronary computed tomography coronary angiography].

OBJECTIVE: To evaluate the value of dual source computed tomography coronary angiography (DSCT-CA) on detecting in-stent restenosis (> 50% luminal narrowing) in symptomatic patients referred for quantitative coronary angiography (QAC). METHODS: Fifty five patients (43 males) with chest pain after coronary stent implantation within 6 - 12 months were evaluated by DSCT-CA and QAC. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of DSCT-CA were calculated using coronary angiography as gold standard. RESULTS: Eighty nine stents were implanted. In-stent restenosis was evidenced in 28 stents (31.5%) by QAC. The sensitivity, specificity PPV and NPV of DSCT-CA for the diagnosis of in-stent restenosis was 89%, 87%, 76% and 95%, respectively. Diagnostic efficiency was not affected by heart rate and the sensitivity was 0.94 vs. 0.82, the specificity 0.88 vs. 0.90, the PPV 0.76 vs. 0.75 and the NPV 0.97 vs. 0.93 (all P > 0.05) between patients with heart rate < 70 beats/min and patients with heart rate ≥ 70 beats/min. The sensitivity (84% vs. 100%), specificity (81% vs. 96%), PPV (70% vs. 90%) and NPV (91% vs. 100%) were similar between overlapping or bifurcations stents and single stents. The specificity (100% vs. 80% vs. 66%) and PPV (100% vs. 95% vs. 53%) were significantly higher in the groups with stents ≥ 3.50 mm, stents 3.00 mm than in stents ≤ 2.75 mm (both P < 0.05). CONCLUSION: Diagnostic efficiency of in-stent restenosis with DSCT-CA in the large diameter stent is better than in the small diameter stent and the diagnosis efficacy is not affected by heart rate and stent distribution.

[Time course of C4a and platelet aggregation rates in no-reflow patients with acute myocardial infarction undergoing percutaneous coronary intervention].

OBJECTIVE: To observe serum C4a and platelet aggregation rates changes in acute myocardial infarction (AMI) patients before and after percutaneous coronary intervention (PCI) and association with the development of no-reflow phenomenon. METHODS: From June 2006 to August 2009, 119 AMI patients underwent PCI (28 cases of no-reflow group, 91 cases of reflow group) and 30 subjects with suspected coronary heart diseases and normal coronary angiography results (control group) were enrolled in this study. C4a and platelet aggregation rate were measured at 30 minutes before PCI, immediately after PCI, 30 minutes, 1 hour, 2 hour, and 6 months post PCI in AMI patients and at before coronary angiography in control subjects. RESULTS: The levels of serum C4a at 30 minutes prior to PCI in control, no-reflow, and reflow groups were similar (P > 0.05). Platelet aggregation rate at 30 minutes prior to PCI was significantly higher in no-reflow group and reflow group than in control group (all P < 0.05). Serum C4a and platelet aggregation rates were significantly higher in no-reflow group at immediate, 30 minutes and 1 hour after PCI than at 30 minutes prior to PCI, two hours and 6 months after PCI (all P < 0.05), and were significantly higher than in reflow group at immediate, 30 minutes and 1 hour after PCI (all P < 0.05). Serum C4a and platelet aggregation rates were similar at different time points in reflow group (all P > 0.05). The levels of C4a in no-reflow group at immediate, 30 minutes and 1 hour after PCI were positively correlated with platelet aggregation rates (r = 0.91, 0.79, 0.60, respectively, all P < 0.01). CONCLUSION: The transient increase on levels of C4a and platelet aggregation rate early post PCI are verified in no-reflow patients with AMI undergoing PCI.

Increasing DHA and EPA concentrations prolong action potential durations and reduce transient outward potassium currents in rat ventricular myocytes.

The goal of this study was to determine the mechanisms of n-3 polyunsaturated fatty acids (n-3 PUFA) on anti-arrhythmias and prevention of sudden death. The calcium-tolerant Sprague-Dawley rat ventricular myocytes were isolated by enzyme digestion. Effects of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on action potentials and transient outward potassium currents (I (to)) of epicardial ventricular myocytes were investigated using whole-cell patch clamp techniques. Action potential durations (APDs) and I (to) were observed in different concentrations of DHA and EPA. APD(25), APD(50), and APD(90) with 0.1 µmol/L DHA and EPA were prolonged less than 15% and 10%. However, APDs were prolonged in concentration-dependent manners when DHA and EPA were more than 1 µmol/L. APD(25), APD(50), and APD(90) were 7.7 ± 2.0, 21.2 ± 3.5, and 100.1 ± 9.8 ms respectively with 10 µmol/L DHA, and 7.2 ± 2.5, 12.8 ± 4.2, and 70.5 ± 10.7 ms respectively with 10 µmol/L EPA. I (to) currents were gradually reduced with the increased concentrations of DHA and EPA from 1 to 100 µmol/L, and their half-inhibited concentrations were 2.3 ± 0.2 and 3.8 ± 0.6 µmol/L. The results showed APDs were prolonged and I (to) current densities were gradually reduced with the increased concentrations of DHA and EPA. The anti-arrhythmia mechanisms of n-3 PUFA are complex, however, the effects of n-3 PUFA on action potentials and I (to) may be one of the important mechanisms.

[Regulation of vascular tension in diabetic coronary artery by large conductance Ca(2+)-activated K(+) channel in rats].

OBJECTIVE: to investigate the regulation in vascular tension of diabetic coronary artery by large conductance Ca(2+)-activated K(+) channel (BK channel) and to elucidate the mechanisms of coronary dysfunctions due to diabetes. METHODS: regulation of vascular tension in normal coronary artery was evaluated by videomicroscopy system. Streptozotocin-induced rat diabetic animal model was established successfully by intraperitoneal injection. Coronary smooth muscle cells were isolated by enzyme digestion. The BK currents in control and diabetic groups were recorded by patch clamp technique in whole cell configuration. Changes of vascular tension in normal and diabetic coronary arteries were assayed by multi-wire myograph system. RESULTS: more than 50% was contracted in inner diameters of coronary arteries when 100 nmol/L IBTX, a specific BK channel blocker, was applied. In comparison with normal group, the BK current densities in diabetic group significantly decreased when test potentials were more than 60 mV (P < 0.05). The BK current densities at 150 mV in normal group and diabetic group were (275 ± 40) pA/pF and (70 ± 10) pA/pF respectively. When 100 mmol/L KCl was washed out, vascular tensions of normal and diabetic coronary artery were (398 ± 38) mg and (390 ± 35) mg respectively (P > 0.05); however, when 100 nmol/L IBTX was added, the vascular tensions of normal and diabetic coronary artery were (395 ± 40) mg and (50 ± 7) mg (P < 0.05). CONCLUSION: BK channels play an important role in the regulation of coronary vascular tension, whereas BK channels in diabetic coronary artery are dysfunction, BK currents decrease and vascular tensions increase.

Docosahexaenoic acid has influence on action potentials and transient outward potassium currents of ventricular myocytes.

BACKGROUND: There are many reports about the anti-arrhythmic effects of omega-3 polyunsaturated fatty acids, however, the mechanisms are still not completely delineated. The purpose of this study was to investigate the characteristics of action potentials and transient outward potassium currents (Ito) of Sprague-Dawley rat ventricular myocytes and the effects of docosahexaenoic acid (DHA) on action potentials and Ito. METHODS: The calcium-tolerant rat ventricular myocytes were isolated by enzyme digestion. Action potentials and Ito of epicardial, mid-cardial and endocardial ventricular myocytes were recorded by whole-cell patch clamp technique. RESULTS: 1. Action potential durations (APDs) were prolonged from epicardial to endocardial ventricular myocytes (P < 0.05). 2. Ito current densities were decreased from epicardial to endocardial ventricular myocytes, which were 59.50 +/- 15.99 pA/pF, 29.15 +/- 5.53 pA/pF, and 12.29 +/- 3.62 pA/pF, respectively at +70 mV test potential (P < 0.05). 3. APDs were gradually prolonged with the increase of DHA concentrations from 1 micromol/L to 100 micromol/L, however, APDs changes were not significant as DHA concentrations were in the range of 0 micromol/L to 1 micromol/L. 4. Ito currents were gradually reduced with the increase of DHA concentrations from 1 micromol/L to 100 micromol/L, and its half-inhibited concentration was 5.3 micromol/L. The results showed that there were regional differences in the distribution of action potentials and Ito in rat epicardial, mid-cardial and endocardial ventricular myocytes. APDs were prolonged and Ito current densities were gradually reduced with the increase of DHA concentrations. CONCLUSION: The anti-arrhythmia mechanisms of DHA are complex, however, the effects of DHA on action potentials and Ito may be one of the important causes.

[Changes of large conductance Ca(2+)-activated K(+) channels on coronary smooth muscle cells from diabetic rats].

OBJECTIVE: To investigate the changes of large conductance Ca(2+)-activated K(+) channel (BK channel) on coronary smooth muscle cells from diabetic rats. METHODS: Streptozotocin-induced rat diabetic animal model was used. Coronary smooth muscle cells were isolated by enzyme digestion. BK currents in control and diabetic groups were recorded by patch clamp technique in whole cell configuration, and BK channel protein expression was detected by Western blot. Calcium concentration was measured by fluorescence assay. RESULTS: Compared with control group, BK current densities in diabetic group were significantly decreased when test potentials > 100 mV (P < 0.05). BK current densities were (275 ± 40) pA/pF in control group (n = 8) and (70 ± 10) pA/pF in diabetic group (n = 6) at 150 mV test potentials. α-subunit protein expression was similar between the groups (P > 0.05), however, ß1-subunit protein expression was significantly reduced in diabetic group than in control group (P < 0.05). Calcium concentrations were significantly increased in diabetic group control group (151 ± 18) nmol/L (n = 6) than in control group (92 ± 7) nmol/L (n = 5, P < 0.05). CONCLUSION: Observed ß1-subunit downregulation, BK current density decrease and cytosolic calcium concentration increase in smooth muscle cells of diabetic coronary arteries may be associated with coronary dysfunction in diabetic rats.

[Cloning and expression of nematicidal crystal protein gene cry6Aa of Bacillus thuringiensis].

On the basis of the sequencing of the N-terminal amino acid of the crystal protein, a nucleotide acid fragment harboring a novel nematicidal gene cry6Aa2 was obtained from Bacillus thuringiensis strain YBT-1518. This fragment contains two ORFs: orf1 and orf2, while a "stem-loop" exists between orf1 and orf2. BLAST showed the similarity of orf1 nucleotide acid sequence with cry6Aa1 is 98%, and has been deposited in the Genbank database (Acc. No. AF499736). The cloning fragment was transferred to crystal negative mutation strain BMB171 by E. coli-Bt shuttle vector pHT304. A 54kDa protein with similarity to strain YBT-1518 was detected in recombinant strain, and rice shaped crystal was detected with transmission electron microscope. Bioassay indicated the LC50 of recombinant strain against second lavae juvenile of Meloidgyne hapla is 9.47 microg/mL, nearly equal to the original strain YBT-1518 (10.74 microg/mL).