Clinical analysis of 15 cases of traumatic duodenal injury / 中华全科医师杂志

The clinical data of 15 patients with duodenal trauma who were admitted to Shanxi Bethune Hospital from January 2012 to June 2019 were retrospectively analyzed. There were 13 patients with blunt injury and 2 with penetrating injury. The surgical procedure was selected by patient′s condition and extent of injury combined with the clinical symptoms, imaging examination and the Organ Injury Scale grading system of the American Association for the Surgery of Trauma (AAST-OIS). All patients were followed up through outpatient examination and telephone interview till February 2020. Ten patients were diagnosed as duodenal trauma by CT scan before operation, and 5 patients were diagnosed during the operation. According to the AAST-OIS, 1 patient was with grade Ⅰ injury, 6 in grade Ⅱ, 5 in grade Ⅲ, 2 in grade Ⅳ and 1 in grade Ⅴ. All 15 patients received surgical treatment, including 1 with simple suture, 5 with break suture and duodenal diverticularization, 6 with break suture and biliary drainage (3 with hepatocystic duct drainage and 3 with cholecystostomy), 2 with pancreaticoduodenectomy. Postoperative complications occurred in 3 patients with Clavien system classification of Ⅲ b, Ⅱ and Ⅱ. One patient with duodenal stricture and severe abdominal infection was cured after gastrectomy and Billroth Ⅱ gastrojejunostomy 6 months after operation, and 2 cases with duodenal fistula were cured after conservative treatment. One patient who underwent pancreaticoduodenectomy was followed up for 6 months in the outpatient department, and 14 patients were followed up for 6-24 months. For emergency abdominal trauma patients with suspected duodenal injury, surgical exploration should be carried out actively. The site and range of intestinal wall injury should be considered in order to select a reasonable operation. Effective duodenal decompression and complete peritoneal drainage are important for the success of surgery. Early postoperative enteral nutrition support is one of the key measures for successful wound healing.

Academic level assessment of randomized controlled trial abstracts in papers on budesonid adjuvant therapy for children pneumonia / 中华医学图书情报杂志

Objective To assess the academic level of randomized controlled trial abstracts in papers on budesonid adjuvant therapy for children pneumonia and analyze its influencing factors. Methods The randomized controlled tri-al abstracts in papers on budesonid adjuvant therapy for children pneumonia were assessed according to the CON-SORT 2010 Statement and were statistically analyzed using the RevMan 5 . 3 . Results The items with a low reporting rate of the randomized controlled trial abstracts in the 282 papers included in this paper were "title judged as ran-dom","communication author","randomized","blind method","randomized grouping cases","fund-suppor-ted". Hierarchical analysis showed that the number of words in abstracts played an important role in affecting the reported items. Conclusion The academic level of randomized controlled trial abstracts in papers on budesonid adju-vant therapy for children pneumonia is significantly different from that of the abstracts in clinical papers according to the CONSORT 2010 Statement. Researchers should thus use the CONSORT 2010 Statement-defined items in writing their papers in order to improve the academic level and readability of their abstracts.

Optimal proportion of VEGF 165, Ang-1 and bFGF concentration on angiogenesis of transplanted fat / 中华医学美学美容杂志

Objective To explore the optimal formula of vascular endothelial growth factor,angiopoietin and basic fibroblast growth factor on autologous fat angiogenesis and tissue proliferation.Methods Wistar rat mesenteric fat in 9 groups trimmed into particles were added a 6μl complex solution of the three factors in the formula of 1 ∶ 0 ∶ 0,0 ∶ 1 ∶ 0,0 ∶ 0 ∶ 1,1/2 ∶ 1/2 ∶ 0,0 ∶ 1/2 ∶ 1/2,1/2 ∶ 0 ∶ 1/2,1/3 ∶ 1/3 ∶ 1/3,2/3 ∶ 1/6 ∶ 1/6,1/6 ∶ 2/3 ∶ 1/6,then injected in each rat subcutaneously.15 weeks later the transplantated fat was removed,to observe the fat cell appearance and counting the number of capillaries in the graft.Statistical genetic algorithm was used to set up a Scheffer egression model to optimize fat angiogenesis number.Results In one growth factor group fat vacuoles was uneven size;in two growth factors group,fat cell size tended to be homogeneous and in the three growth factor group,fat cell size was uniformity;the highest angiogenesis rate was 12.092,when the formula of VEGF165,Ang-1 and b-FGF was 0.380∶0.280:0.340.Conclusions Formula of VEGF165,Ang-1,bFGF at 0.380 ∶ 0.280 ∶ 0.340 could improve blood vessels density and increase implanted fat survival.

Preparation and measurement of sodium tanshinone Ⅱ-A sulfonate in mice serum and effects on big conductance calcium-activated potassium channels in porcine coronary artery smooth muscle cells / 重庆医学

Objective To discuss a method combining serum‐pharmacology and electrophysiology technology ,and to research the mechanism of dilating porcine coronary artery of sodium tanshinone Ⅱ‐A sulfonate (DS‐201) .Methods To give mice intragastric administration solution and measure DS‐201 concentration in mice serum ,and apply the serum to single channel patch to research its effect on big conductance calcium‐activated potassium channels(BKca ) in porcine coronary artery smooth muscle cells (PCASMCs) . Results The linear range of concentration containing DS‐201 serum was 0 .73 to 1 .91 μg/mL (r=0 .997 7) ,the recycle rate was 99 .85% -101 .47% ,and the concentration was(7 .32 ± 4 .25)μg/mL ;the result indicates that serum containing DS‐201 has activa‐tion effects on BKCa in PCASMCs ,while there was no statistical significance (P>0 .05) .Conclusion The establishment method of the alcohol extraction of Danshen is useful and reliable .The HPLC method of measuring DS‐201 concentration is precise .Choosing higher quality drugs or raising bioavailability can improve combination of the serum pharmacology and electrophysiological tech‐nique .

Effect of cigarette smoking on rat wound healing / 中华医学美学美容杂志

Objective To observe the effect of cigarette smoking on cutaneous wound healing in rats.Methods Healthy adult SD rats,weight 200-250 g,were randomly divided into 4 groups:control group (group C),low tar content group (group L),middle tar content group (group M) and high tar content group (group H),ten rats each group.4 full thickness dermal excision wound models with the diameter of 2.0 cm were established on the back of 40 healthy male or female SD rats.The wound spacing was greater than 2 cm.Group C did not do any intervention treatment,Groups L,M and H rats were put,respectively,into homemade smoke box in 0.1,0.5,and 0.8 mg different-grade tar content of cigarettes and smoked,and the time of wound healing was observed.The wound granulation tissue was taken in 3 and 7 days after surgery.The expression of CD68+ macrophages was detected by immunohistochemical method.The wound healing rate was observed on the days 7 and 16.Results Compared with group C,wound healing time in groups L,M and H was extended (P＜ 0.05).Immunohistochemical results showed that macrophage numbers in groups L,M and H wound were significantly less than that of group C.The wound healing rates 7 days and 16 days after surgery in the three group smoked were significantly lower than that of group C.Conclusions Cigarette smoking leads to wound healing delay,and wound healing rate is reduced at fixed time point,with the decrease in the number of macrophages.

Combined application of multiple local flaps in facial aesthetic reconstruction / 中华医学美学美容杂志

Objective The study combined multiple local flaps to repair small or medium-sized area of facial skin and soft tissue defects,and to explore the advantages of the local flap collaboration repair.Methods Following the partition repair principle and depending on the wound size and location of these defects,the appropriate local flap was selected to cover the wound.Therefore,the incision was hidden and conformed to the face natural contour or skin wrinkles.Results 77 patients were treated in this group,74 cases got phase] healing and the other 3 got phase Ⅱ healing; all were followed-up for 1 to 8 months.The repair flap and surrounding skin had good similarity in terms of color,texture and contour,the incisions were hidden and the scars were not obvious; no tumor had recurred.The face contour and visual effects were good,and the aesthetic results were satisfactory.Conclusions The combined application of several different local skin flap to repair facial trauma defects,can not only reduce the overall difficulty and risk,reduce surgical complications,but also improve the repair quality,to maximize the recovery of facial aesthetic appearance.

Effect of San-huang-sheng-fu oil on wounds of full-thickness scald in rabbits / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the effect of San-huang-sheng-fu oil on wounds of full-thickness scald in rabbits.</p><p><b>METHODS</b>Full-thickness scald wounds with area of 6 cm(2) were reproduced on both sides of the back in 9 experimental rabbits by water vapor. These rabbits were divided into sesame oil (S1), San-huang-sheng-fu oil (S2), and mupirocin ointment (M) groups according to the random number table, with 3 rabbits (6 wounds) in each group. Two wounds of each rabbit in the three groups were respectively treated with sesame oil, San-huang-sheng-fu oil, and mupirocin ointment, in a dose of 0.15 mL/cm(2), 2-3 times per day. The general condition of wounds was observed on post scald day (PSD) 1, 11, 22, and 45. The wound healing time was recorded. The wound healing rate was calculated on PSD 5, 11, 15, and 22. All the rabbits were sacrificed on PSD 45, and wound tissues were subjected to histomorphological study with HE staining. The protein expressions of transforming growth factor β1 (TGF-β1), basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) were observed with immunofluorescence staining for the other part of wound tissues. Data were processed with one-way analysis of variance or LSD-t test.</p><p><b>RESULTS</b>(1) The wound healing quality of rabbits in S2 group was better than that in the other two groups. (2) The wound healing time of rabbits in S2 group [(11.2 ± 2.3) d] was significantly shorter than that in S1 group [(21.2 ± 3.1) d, t = 2.591, P < 0.05]. (3) The wound healing rate of rabbit in each group was increased gradually on PSD 5-22. The wound healing rates of rabbits in S2 group on PSD 5-22 were significantly higher than those in S1 group (with t values from 3.920 to 8.605, P values all below 0.05). (4) Histomorphological observation showed that the structure of wound tissues in S2 group was in much better integrity than that in the other two groups, including regenerated hair follicles in the corium layer and regularly arranged collagen fibers. The protein expressions of TGF-β1, bFGF, and VEGF in S2 group were all higher than those in the other two groups.</p><p><b>CONCLUSIONS</b>San-huang-sheng-fu oil can up-regulate the protein expressions of TGF-β1, bFGF, and VEGF, induce vascular regeneration, promote wound healing, and shorten wound healing time.</p>

Increased small conductance calcium-activated potassium channel (SK2 channel) current in atrial myocytes of patients with persistent atrial fibrillation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To compare the amplitude of the SK2 current (small conductance calcium-activated potassium channel) in human atrial myocytes with or without persistent atrial fibrillation (AF).</p><p><b>METHODS</b>Right atrial appendage was obtained from 15 patients with sinus rate (SR) and 7 patients with AF underwent surgical valve replacement. Single myocyte was isolated by enzymatic dissociation method and the SK2 channel current density was recorded using whole-cell patch clamp techniques to detect the changes. Immunofluorescence was used to observe SK2 channel protein distribution on right atrial appendage.</p><p><b>RESULTS</b>Using the whole cell patch-clamp recording techniques, an inward rectifier K(+) mix currents could be obtained from both SR (n = 15) and AF (n = 7) samples, I(K1) mix currents density in single myocyte of AF group was significantly increased than in SR group [(-16.42 ± 5.32) pA/pF vs (-6.59 ± 2.24) pA/pF, P < 0.01], which could be partially inhibited by apamin (100 nmol/L). The apamin-sensitive current was obtained by subtraction of the currents before and after treatment with apamin. SK2 current density was significantly increased in AF group than that of SR group [(-9.81 ± 2.54) pA/pF vs (-3.67 ± 0.37) pA/pF, P < 0.01]. SK2 channel protein was evidenced with immunofluorescence method in right atrial appendage from AF group and SR group.</p><p><b>CONCLUSION</b>SK2 channel protein and current were present in atrial myocytes. The SK2 current density was significantly increased in AF group than in SR group suggesting that the increase of SK2 current might contribute to the electrical remodeling in AF patients.</p>

Expression and characterization of the dermonecrotic toxin gene of Bordetella bronchiseptica / 生物工程学报

Dermonecrotic toxin (DNT) is identified as one of the most important virulence factor of Bordetella bronchiseptica. The complete coding sequence (4 356 bp) of the dnt gene was cloned into the prokaryotic expression vector pET-28a, and expressed in the Eschierichia coli BL21 (DE3) under IPTG (Isopropyl-beta-D-thiogalactopyranoside) induction. The recombinant His6-DNT protein showed immunological reactivity in the Western-blot analysis. The recombinant protein was purified from crude lysates of BL21 harboring pET-DNT with the purity of 93.2%. His6-DNT showed the dermonecrotic effects in the infant mouse assay. However, rabbit anti-serum against recombinant DNT protein could neutralize the dermonecrotic effects of native DNT to the infant mice in vivo. These findings suggest that the recombinant DNT protein retained the characteristics and immunogenicity of native DNT. Furthermore, this approach could be used to induce active immunity and serum immunoglobulin for production of a passive therapeutic reagent. In this study, we have shown that the recombinant His6-DNT protein retained the characteristics of native DNT of B. bronchiseptica, which built a good foundation for the further research on the structure and function of DNT.

Comparison of the effect between Jejunostomy with indwelling nasogastric feeding tube in the patients with total gastrectomy / 中国基层医药

Objective To explore the effect of the surgical technique of jejunum fistula and conventional indwelling nasogastric tube with total gastrectomy. Methods The clinical data of 23 advanced gastric cancer patients with total gastrectomy were retrospetively analyzed. Among 23 cases, 17 received jejunum fistual and 6 received indwelling nasogastric. The time to flatus and the ratio of postoperative complications including throat ache, nausea,pneumonia, anastomotic leak were compared. Results Compared with A group, the incidence of disadvantage spit sputum, dyssomnia, throat ache and nausea in B group reduced significantly, the time to flatus was advanced in B group. And other postoperative complications had no difference between two groups. Conclusion Jejunum fistula was rational, safe and effective in patients with total gastrectomy

Treatment of shearing-type and comminuted talar body fractures / 中国骨伤

<p><b>OBJECTIVE</b>To study the treatment and therapeutic effects in the shearing-type and comminuted talar body fractures.</p><p><b>METHODS</b>From October 1988 to September 2005,34 patients with shearing-type or comminuted talar body fractures were followed up. There were 19 males and 15 females ranged from 13 to 55 years (averaged 28.8 years). The disease course ranged from 3 to 14 days (averaged 6.0 days). Ten patients with a displacement of no more than 3 mm were treated with plastic cast. Eighteen patients were treated with open reduction and internal fixation, 6 patients were treated with joint fusion. The assessment of clinical efforts depend on patients' ache, active range of the joint and limp.</p><p><b>RESULTS</b>The mean follow up was 5.04 years (ranged from 3 to 19 years). All the patients were healed. The clinical outcomes were evaluated according to Hawkins evaluation score in which ache, active range of the joint and limp was respectively acssessed. There were 6 patients reached an excellent result, 9 good, 11 fair and 8 poor. Fifteen patients had osteonecrosis, 18 patients had traumatic arthritis of ankle joint, and 14 patients had traumatic arthritis of subtalar joint.</p><p><b>CONCLUSION</b>Patients whose displacement of fracture is not more than 3 mm should be treated with plastic cast. Operation and internal fixation should be performed in patients whose displacement of fracture is more than 3 mm after close reduction. Joint fusion should be performed in patients whose talar body fracture is comminuted severely and the surface of joint can not be repaired. The patients of talar body scissored fracture or comminuted fracture has bad prognosis.</p>

Atrial myocytes KChIP2 mRNA expression in rheumatic heart disease patients with atrial fibrillation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To detect the KChIP2 mRNA level in rheumatic heart disease patients with or without atrial fibrillation (AF) by real-time PCR.</p><p><b>METHODS</b>Right atrial appendage samples from rheumatic heart disease patients with (n = 17) or without AF (n = 13) were obtained during cardiac surgery. Total RNA was extracted from the atrial tissues, and the KChIP2 and Kv4.3 mRNA were detected by SYBR Green I real-time PCR with the GAPDH as the house keeping gene.</p><p><b>RESULT</b>The ratio of KChIP2/GAPDH (0.1468 +/- 0.0452 vs. 0.2200 +/- 0.0388, P<0.01) and the ratio of Kv4.3/GAPDH (0.3946 +/- 0.1826 vs. 0.5257 +/- 0.1427, P<0.05) were significantly lower in AF patients compared to non-AF patients.</p><p><b>CONCLUSION</b>Down-regulated atrial KChIP2 and Kv4.3 mRNA expressions in rheumatic heart disease patients with chronic AF might be one of the molecular bases responsible for the down-regulation of the I(to) current density of AF.</p>

UTP regulates spontaneous transient outward currents in porcine coronary artery smooth muscle cells through PLC-IP(3) signaling pathway / 生理学报

The aim of the present study was to investigate the effects of inositol 1,4,5-trisphosphate (IP(3))-generating agonist UTP on spontaneous transient outward currents (STOCs), and explore the role of intracellular Ca(2+) release in the current response mediated by IP(3) in porcine coronary artery smooth muscle cells (CASMCs). The coronary artery was excised from the fresh porcine heart and cut into small segments (2 mm × 5 mm) and then transferred to enzymatic dissociation solution for incubation. Single CASMCs were obtained by two-step enzyme digestion at 37 °C. STOCs were recorded and characterized using the perforated whole-cell patch-clamp configuration in freshly isolated porcine CASMCs. The currents were amplified and filtered by patch-clamp amplifier (Axopatch 200B), and then the digitized data were recorded by pClamp 9.0 software and further analyzed by MiniAnalysis 6.0 program. The results were as follows: (1) UTP led to conspicuous increases in STOC amplitude by (57.54±5.34)% and in frequency by (77.46±8.42)% (P<0.01, n=38). (2) The specific blocker of phospholipase C (PLC) - U73122 (5 μmol/L) remarkably reduced STOC amplitude by (31.04±7.46)% and frequency by (41.65±16.59)%, respectively (P<0.05, n=10). In the presence of U73122, UTP failed to reactivate STOCs (n=7). (3) Verapamil (20 μmol/L) and CdCl2 (200 μmol/L), two blockers of L-type voltage-dependent Ca(2+) channels, had little effects on STOCs initiated by UTP (n=8). (4) 1 μmol/L bisindolylmaleimide I (BisI), a potent blocker of protein kinase C (PKC), significantly increased STOC amplitude by (65.44±24.66)% and frequency by (61.35±21.47)% (P<0.01, n=12); UTP (40 μmol/L), applied in the presence of 1 μmol/L BisI, could further increase STOC activity (P<0.05, P<0.01, n=12). Subsequent application of ryanodine (50 μmol/L) abolished STOC activity. (5) In the presence of UTP (40 μmol/L), inhibition of IP(3) receptors (IP(3)Rs) by 2-aminoethoxydiphenyl borate (2-APB, 40 μmol/L) reduced STOC amplitude by (24.08±3.97)% (P<0.05, n=8), but had little effect on STOC frequency (n=8). While application of 2-APB (80 μmol/L) significantly reduced STOC amplitude by (31.43±6.34)% and frequency by (40.59±19.01)%, respectively (P<0.05, P<0.01, n=6). Subsequent application of ryanodine (50 μmol/L) completely blocked STOC activity. Pretreatment of cells with 2-APB (40 μmol/L) or ryanodine (50 μmol/L), UTP (40 μmol/L) failed to reactivate STOCs. The results suggest that UTP activates STOCs mainly via PLC and IP(3)-dependent mechanisms. Complex Ca(2+)-mobilization pathways are involved in UTP-mediated STOC activation in porcine CASMCs.

Characteristic of spontaneous transient outward potassium currents in vascular smooth muscle cells of porcine coronary artery / 生理学报

Spontaneous transient outward currents (STOCs) play an important role in the myogenic regulation of small artery tone, such as coronary artery. In the present study, we investigated the electrophysiological properties and the regulation of STOCs in vascular smooth muscle cells (VSMCs) of porcine coronary artery by perforated patch-clamp technique. Our data showed that STOCs were dependent on voltage and extracellular calcium and they were highly variable in amplitudes and frequencies. STOCs superimposed stochastically onto whole-cell K(+) currents induced by step and ramp protocols. STOCs were completely abolished by ChTX [inhibitor of large-conductance Ca(2+)-activated potassium (BK(Ca)) channels], removal of extracellular Ca(2+), or addition of ryanodine (50 mumol/L) respectively. In contrast, CdCl2 and verapamil, inhibitors of voltage-dependent L-type Ca(2+) channels, had little effect on STOCs. Caffeine (5 mmol/L) transiently increased STOCs (hump), followed by a temporary inhibition. Ca(2+) ionophore A23187 increased both amplitude and frequency of STOCs. Na(+) ionophore monensin increased the frequency of STOCs. STOCs were strongly inhibited by KB-R7943, a selective inhibitor of the reverse mode of the Na(+)/Ca(2+) exchanger. Based on these observations, we conclude that STOCs are mediated by BK(Ca) channels. The generation and activation of STOCs depend upon Ca(2+) influx through Na(+)/Ca(2+) exchange and release of Ca(2+) from sarcoplasmic reticulum (SR) via ryanodine receptors. This suggests that Na(+)/Ca(2+) exchange determines calcium store refilling. Recycling of entering Ca(2+) from superficial SR may locally elevate Ca(2+) concentration at the plasma membrane, thereby activating BK(Ca) channels and then initiating STOCs.

Separation and refine of Xiaoyao Pill by macroporous adsorption resin / 中国中药杂志

<p><b>OBJECTIVE</b>To search for the method used in refining Xiaoyao Pill by macroporous adsorption resin, 12 types of macroporous adsorption resin were optimized.</p><p><b>METHOD</b>Static and dynamic adsorption test and de-adsorption test were carried out to screen the best macroporous resin. The single factor test was applied to optimize the manipulation parameters of macroporous resin.</p><p><b>RESULT</b>The macroporous resin D-101-1 possessed the strongest adsorption ability, in addition to an easy de-adsorption property.</p><p><b>CONCLUSION</b>The D-101-1 type macroporous adsorption resin shows better comprehensive adsorption property. It is available for the refine Xiaoyao Pill.</p>

An improved method for isolation of single atrial myocyte from human heart / 生理学报

To approach the method of isolation of tolerant human atrial myocytes, single myocytes were isolated by modified procedure of enzymatic dissociation with protease (type XXIV) and collagenase (type V). L-type calcium channel current (I(Ca-L)), sodium current (I(Na)), transient outward potassium current (I(to1)), and inward rectifier potassium current (I(K1)) in isolated atrial myocytes were recorded by using whole-cell patch-clamp techniques. Single cardiocytes isolated by this method were smooth, well-striated and rod-shaped. The yields of recordable myocytes, which viable and calcium-tolerant for electrophysiological studies, were 50%-60% of the total isolated cells. Compared with other isolation methods, this method was simple and steady, but with yield of a great number of qualified myocytes. The currents recorded in these cells were functional and active. Our research suggests that the myocytes isolated by the described method in this paper have normal electrophysiological function and are appropriate for patch-clamp experiments.

Effects of tetramethylpyrazine on large-conductance Ca²⁺-activated potassium channels in porcine coronary artery smooth muscle cells / 生理学报

The aim of the present study was to examine the effects of tetramethylpyrazine (TMP) on large-conductance Ca(2+)-activated potassium channels (BK(Ca) channels) in porcine coronary artery smooth muscle cells, in order to provide the experimental evidence for expounding the mechanism of TMP in dilating coronary artery. Cell-attached and inside-out single channel recording techniques were used to observe the effects of TMP on BK(Ca) channels as well as the effects after the cells were treated by protein kinase A (PKA) inhibitor or protein kinase G (PKG) inhibitor. In inside-out patch, TMP activated BK(Ca) channels by increasing open-state probability (N(Po)) and decreasing close time (Tc) in a concentration-dependent manner. TMP (0.73~8.07 mmol/L) in the bath solution increased N(Po) from (0.01+/-0.003) to (0.03+/-0.01)~(1.21+/-0.18) (P<0.01, n=10), and decreased Tc from (732.33+/-90.67) ms to (359.67+/-41.30) ~ (2.96+/-0.52) ms (P<0.01, n=10). These actions of TMP occurred even when the free Ca(2+) concentration in the bath was reduced to ~ 0 mmol/L. The specific inhibitors of PKA (H-89, 3 mumol/L) and PKG (KT-5823, 1 mumol/L) had no influence on the activation of TMP on BK(Ca) channels. These findings suggest that TMP can directly activate BK(Ca) channels in coronary artery smooth muscle, which probably is an important mechanism in dilating coronary artery.

Human inward rectifying potassium current and Kir2.1 mRNA expression in myocytes isolated from patients with chronic atrial fibrillation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To compare the changes of both inward rectifying K(+) (Kir) current(I(k1)) density and mRNA expression level of Kir2.1, a major subfamily of Kir in chronic human atrial fibrillation (CAF) with those in normal sinus rhythm (NSR).</p><p><b>METHODS</b>I(k1) density was measured with whole-cell patch clamp technique in single myocyte isolated by an enzymatic dissociation method from right atrial appendages in patients with CAF (n = 8) and those with NSR (n = 12). The mRNA expression levels of Kir2.1 was determined in right atrial appendages from CAF (n = 19) and NSR (n = 18) by semiquantitative reverse-transcription polymerase chain reaction (RT-PCR).</p><p><b>RESULT</b>The average resting membrane potentials were similar between CAF and NSR (-78.95 mV +/- 4.67 mV and -70.22 mV +/- 11.08 mV, P>0.05). I(k1) density in single myocyte significantly increased at hyperpolarized potential level (-100 mV) in CAF compared to that in NSR (-9.59 pA/pF +/- 2.47 pA/pF vs. -5.58 pA/pF +/- 2.52 pA/pF, P<0.01). The mRNA level of Kir2.1 was also significantly higher in CAF than that of NSR (0.50+/-0.16 vs. 0.34+/-0.09, P<0.05).</p><p><b>CONCLUSION</b>The data suggest that Kir2.1 up-regulation and I(k1) current increase might contribute to the electrical remodeling in CAF patients.</p>

Research of L-type Ca2+ channel current in atrial myocytes of patients with chronic atrial fibrillation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the changes of L-type Ca(2+) channel current (I(Ca-L)) and its voltage-dependent activation and inactivation in atrial myocytes of patients with atrial fibrillation (AF).</p><p><b>METHODS</b>The specimens of right atrial appendage were obtained from 18 patients with normal sinus rhythm (NSR) and 12 patients with chronic atrial fibrillation (CAF). Single myocytes were isolated by enzymatic dissociation with two-step method and the ionic currents were recorded using whole-cell patch clamp techniques to detect the changes of I(Ca-L) density and kinetic properties.</p><p><b>RESULTS</b>(1) I(Ca-L) density was (-1.32 +/- 0.19) pA/pF in CAF group (n = 12) and (-4.58 +/- 0.39) pA/pF in NSR group (n = 21) at the test potential from -40 mV to 0 mV. I(Ca-L) density of CAF group was significantly reduced (P < 0.01), compared with the NSR group. (2) No significant differences were noted between the two groups in the voltage-dependent activation parameters (V(1/2), K) and inactivation parameters (V(1/2), K).</p><p><b>CONCLUSIONS</b>I(Ca-L) density of CAF group was significantly decreased whereas it's voltage-dependent kinetic properties had no change. This phenomenon may be one of the mechanisms of atrial electrophysiological remodeling in chronic atrial fibrillation.</p>

Effect of IP3 on BK channels of porcine coronary artery smooth muscle cells / 生理学报

D-myo-inositol 1,4,5-trisphosphate (IP(3)) plays an important role in signal transduction. It releases Ca(2+) from intracellular sites, which activates the Ca(2+)-dependent channels such as large-conductance Ca(2+)-activated potassium channels (BK channels). The present study was therefore designed to determine if the activity of BK channels in porcine coronary artery smooth muscle cells was increased by IP(3). Using the inside-out patch-clamp technique, the activity of single BK channels was recorded in porcine coronary artery smooth muscle cells. In excised inside-out membrane patches, IP(3) (10-50 micromol/L) enhanced the open probability (Po) of BK channels in a dose-dependent manner in the intracellular side of inside-out patches and its effect was almost completely abolished by washout. The open-state probability of the BK channels increased from a control level of 0.0402+/-0.0152 to 0.1365+/-0.0212 (20 micromol/L IP(3)) and 0.1865+/-0.0175 (30 micromol/L IP(3)). IP(3) decreased the mean close time markedly, but had no effect on the amplitude of BK channels. The activation of IP(3) on BK channels did not decline. The metabolite of IP(3) had no obvious effect on BK channels. This study provides evidence that IP(3) activates BK channels in porcine coronary artery smooth muscle cells in a dose-dependence manner.