BACKGROUND: The implantation of electronic devices has become the preferred treatment tor symptomatic bradyarrhythmias.However,there are many shortcomings in electronic pacemakers.The usage of molecular biology principle to develop biological pacemaker has become a topic of discussion in research.When sinoatrial node is lnhlblted,pacemaker effect runs by transfecting hyperpolarization-activated cyclic nucleotide-gated(HCN)channel gene of If current,overexprcssing HCN,and increasing inward current in diastolic phase of the heart.Construction of biological pacemakefs by gene therapy and cell therapy may become an optimal substitute of electronic pacemakers in the near future.OBJECTIVE:To sum up the research advancement in application of HCN channel gene to the development of biological pacemaker.RETRIEVAL STRATEGY:The relevant articles published between January 1979 and June 2007 were searched for in Pubmed database by researcher of this article with the key words of"hyperpolarization-activated cyclic nucleotide-gated chartnel,biological pacemaker"in English.157 articles were selected and reviewed by the inclusive cntena of:① articles closely related with the application of HCN to the development of biological pacemaker;②the late articles and articles in anthority journals in the same field.Exclusive criterion:repetitive studies.LITERATURE EVALUATION:The main sources of literatures were randomized clinical trial(RCT)on biological pacemaker by HCN.Among 36 selected articles,10 were reviews,and others were elementary expenInental studles.DATA SYNTHESIS:①Of all four HCN isoforms,HCNI,HCN2,and HCN4 are the main isoforms in the heart.HCN3 only expresses in embryonic pacemaker cells in a low level.HCN2 highly expressed in low pacing regions(Ventricular muscle),whereas HCN4 highly expressed in high pacing regions.Moreover,HCN2 are the main isoforms in the ventricle.Expression ratio of HCN2 to HCN4 is 5:1 in neonate rats and 13:1 in adult rats.②Defects in HCN channels may underlie sick-sinus syndrome.③Up to now,HCN genes of If current contribute importantly to the generataon of the regular pacemaker potential.CONCLUSION:Gene therapy and cell therapy have become an optimal approach to improve biological paccmakers.Application of HCN channel gene in development of biological pacemaker may hold great promlse In the treatment of chronic arhythmia.

Objective To investigate the role of large conductance calcium-activated potassium channels (BK) in neuronal Ca2+ overload following traumatic brain injury (TBI). Methods Neuronal cells of C57BL/6 mouse cortex were collected and cultured. Patch-clamp technique was applied to investigate the changes of intracellular free calcium [Ca2+] i and firing frequency of neuronal action potentials in rest condition or evoked by 100 pA electric current lasting 500 ms after perfusion of Iberiotoxin ( 100 nmmol/L), a BK specific blocker. The cells were divided randomly into experimental group ( plus Iberiotoxin) and control group. Extracellular solution of cultured neurons was further perfused with KCl (20 mmol/L) to induce elevation of [Ca2 +]i and influence of Iberiotoxin ( 100 nmol/L) on amplitude of [Ca2 +] i elevation was determined. Results No significant changes of neuronal spontaneous action potential frequency and [Ca2 +]i were observed in rest condition after perfusion of Iberiotoxin (P＞0.05).However, when evoked by electric current, the frequency of action potential was (10.4 ± 3.0) Hz,which was increased to ( 13.8 ± 3.7 ) Hz after perfusion of Iberiotoxin, with statistical difference (P＜0.05 ). The [Ca2 +] i level was ( 14.21 ± 16.98 ) nmol/Lbefore perfusion with Iberiotoxin but was increased to (44.07 ± 34. 4) nmol/L after perfusion of Iberiotoxin (P ＜ 0.05 ). Extracellular high concentration of KCl increased [Ca2 +] i of neurons, while perfudion of Iberiotoxin further elevated [Ca2 +]i (P ＜ 0.05).Conclusion BK may play an important role in the regulation of neuronal [Ca2+] i and in neuronal Ca2+overload following TBI.

Objective To study the relationships between hemoglobin concentration,cytokine and cardiac function in patients with ischemic cardiomyopathy.Methods Hemoglobin concentration,sernm TNF-α,IL-6 in 121 patients with ischemic cardiomyopathy were measured,left ventricular ejection fraction(LVEF)by echocardiography,according to hemoglobin concentration,these patients were distributed to the anemic group and the non-anemic group,contrasting to 27 healthy persons.Results The levels of serum TNF-α,IL-6 in the anemic patients group were higher than those in the non-anemic group subjects,but LVEF Wag lower.With the increase of anemia severity,the levels of serum TNF-α,IL-6 significantly increased;there was a positive correlation between LVEF and the levels of serum TNF-α,IL-6(P＜0.01),and a negative correlation between LVEF and Hb concentration.Conclusion The levels of cytokine promote the pathophysiological procedure between cardiac failure and anemic in ICM.

Objective To identify the causes of coronary angiographic hazy lesions by intravascular ultrasound (IVUS) to avoid inappropriate stenting. Methods Twenty-five cases with hazy regions on coronary angiogram were consecutively identified from July 2009 to March 2010. Hazy regions were defined by coronary arteriongraphy as reduced contrast density without a clearly defined intimal tear, dissection,thrombus,or stenosis ( ＞ 50% ). This cohort of patients were subsequently underwent IVUS examinations and treated according to the results of IVUS. Results The lumen CSAs were settled as ＞ 4. 0 mm2 in all examinations. Among all 25 cases,hazy lesions were located in left anterior descending in 12 patients, right coronary artery in 6 patients, left circumflex in 5 patients, and left main artery in 2 patients. According to the IVUS findings, 2 cases showed absolutely normal or near-normal arterial wall structure image, 10 cases showed calcified plaque,5 cases showed plaque rupture,3 cases showed eccentric plaque ,2 cases showed thrombosis formation,2cases showed dissection,1 case showed subintimal hematoma. Seven patients received stent implantation, and the rest accepted medical therapy. There were no in-hospital MACEs reported among all patients. Conclusion Nearly half of the coronary arteriongraphic hazy lesions were caused by calcified plaque. IVUS can distinguish calcified plaques from intimal tears, thrombus and other underlying etiologies,and help to avoid unnecessary stenting.

0.05).The frequency of action potential evoked by electric current was higher after perfusion of iberiotoxin,as well as thei level during depolarization(n=9,P

Objective To explore the procedure selection of laparoscopic surgery in the treatment of tubal pregnancy.Methods A total of 187 patients with tubal pregnancy was treated either by laparoscopic salpingectomy(102 patients,Group Ⅰ) or by laparoscopic oviduct fenestration(85 patients,Group Ⅱ). Results The surgical time was 40.4?9.9 min in the Group Ⅰ and 88.8?10.3 min in the Group Ⅱ.The intraoperative blood loss was 17.7?5.4 ml in the Group Ⅰ and 80.6?4.4 ml in the Group Ⅱ.The postoperative hospital stay was 3.8?0.5 d in the Group Ⅰ and 7.4?0.9 d in the Group Ⅱ.The postoperative time to normal serum ?-hCG levels was 7~14 d in the Group Ⅰ and 10~33 d in the Group Ⅱ.A follow-up was carried out in 116 patients.No recurrence of ectopic pregnancy happened in the Group Ⅰ(60 patients).In the Group Ⅱ(56 patients),hydrotubation or salpingography revealed patent oviduct in 37 patients,intrauterine pregnancy in 25 patients,and recurrence of tubal pregnancy at the same side in 2 patients. Conclusions Salpingectomy should be the first choice in the treatment of tubal pregnancy because of its short surgical time,short hospital stay,less intraoperative blood loss,and low complication incidence.Oviduct fenestration should be conducted only for patients with child-bearing demands,but we must be on our guard against the possibility of persistent ectopic pregnancy,and a salpingectomy or a conversion to open surgery should be performed immediately once the bleeding can not be stopped effectively during the operation.

A 11-year-old child diagnosed as chronic tonsillitis and adenoid hypertrophy underwent adeno-tonsillectomy under general anesthesia. After surgery, patient complained with abdominal discomfort, paleness and vomiting, which presented as the old black contents. Complete blood count showed: 45.2 g/L, hemoglobin of red blood cells 2.57 x 10(12)/L, An emergency gastroscopy confirmed gastric ulcer with hemorrage. Hemorrage was controlled and complete blood count results restored to normal after supportive therapy. Gastric ulcer completely recovered two weeks after discharge.
Adenoidectomy ; Child ; Humans ; Male ; Peptic Ulcer Hemorrhage ; etiology ; Postoperative Complications ; Stomach Ulcer ; etiology ; Tonsillectomy

Objective To evaluate the clinical effect of dorsal interosseous artery island flap to cover soft tissue defects of the hand.Methods Ten cases (8 males and 2 females) treated between 2009 and 2012 were included.The age was from 15 to 74 years.There were 4 patients associated with mechanical injury,3 electric injury,2 chronic ulcer and 1 hot crush injury.Size of the defect ranged from 3.0 cm × 2.5 cm to 12.0 cm × 7.0 cm,and the size of the flap ranged from 4.0 cm× 3.0 cm to 13.0 cm × 8.0 cm.The portable Doppler ultrasound was employed to locate the branches from the forearm dorsal interosseous artery.The dorsal interosseous retrograde artery distally based was used to repair hand softtissue defects.Results All the flaps survived except for some necrosis in one case which healed after dressing change.Eight patients were followed up for 3 months to 1 year and two patients were lost to follow-up.Flap had soft texture and similar color and sensation as the adjacent skin.No apparent hypertrophic scarfing on the donor site was observed.Flap was slighdy swollen in one case.Conclusion Dorsal interosseous artery retrograde island flap is safe and effective to repair hand soft tissue defects.

Objective To establish a methodological study pattern of quantitative analysis of multi-components by single marker ( QAMS) , and examine its feasibility and technical applicability in the quality control of compound preparation of traditional Chinese medicine-Jinhoujian spray. Methods Gas chromatographic method ( GC) was used and naphthalene served as the internal standard. Menthol was used as the reference substance. The relative correlation factors ( RCF) of 1,8-Cineole, camphor and borneol to menthol were calculated and established to carry out QAMS.The accuracy of this method was confirmed by comparison of internal standard method. Results The reproducibility of relative correction factor was perfect. The two methods did not show significant difference in 10 bathes of samples. Conclusion The QAMS method is feasible, credible, and can be used to determine active ingredients in Jinhoujian spray.

Objective To investigate the effect of atorvastatin on the expression and activity of matrix metalloproteinases (MMPs) in rabbit abdominal arterial atherosclerotic plaque. Methods Eighteen male New Zealand rabbits weighing 2 kg were randomized to normal control group (n=6) and hypercholesterolemia group (n=12). The latter was given hypercholesterol diet for 2 weeks, and then catheter-induced abdominal aortic wall injury was performed. Rabbits in hypercholesterolemia and aortic injury group were randomized to model group (n=6,4 weeks of hypercholesterol diet) and atorvastatin(5 mg?kg-1?d-1 for 4 weeks)group (n=6). Finally, the levels of MMP2 and MMP9 protein and mRNA in the abdominal aortic artery were measured by immunohistochemical analysis, reverse transcription-polymerase chain reaction (RT-PCR), sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) zymography. Results The intimal-medial thickness[(0. 49?0. 072) mm vs (0.66?0.079) mm, P