Traditional right ventricular pacing is non-physiological pacing, can lead to ventricular electrical and mechanical dyssynchmnization, which increases the risk of heart failure and atrial fibrillation. His-Purkinje system pacing is the hot research of physiological pacing method. The high thresholds and difficult implantation of his bundle pacing limits its application and popularization. In recent years, domestic scholars have proposed left bundle branch area pacing. Many studies have confirmed the safety and feasibility of left bundle branch area pacing. Left bundle branch pacing transmit down the conduction system, which can effectively achieve ventricular electrical and mechanical synchrony, At the same time, it also has many others advantages, such as good and stable electrical parameters, significantly improved cardiac function, and pacing across blocked parts. It will become the main development direction of physiological pacing in the future. This article aims to review the origin, standard and classification, advantages and limitations of left bundle branch area pacing.

Objective To investigate the expression level of endogenetic nitric oxide(NO) in the reproduction process of human anterior cruciate ligament cells. Methods Anterior cruciate ligament cells were isolated and subcultured from the human anterior cruciate ligament. LPS was used to induce the anterior cruciate ligament cell to express the inducible nitric oxide synthase(iNOS ), and N-monomethyl -L-Arginine (L-NMMA) was used as the interdiction of nitric oxide. They were alone or together added in the culture medium of anterior cruciate ligament cells in different groups. The level of NO was indirectly measured in the medium of HACL. Results LPS promoted significantly anterior cruciate ligament cells to produce endogenetic nitric oxide, compared with the control group(P

The strain of DG7 isolated from the oilwater sample in DAGANG oilfield could produce surfactant ?acids and gas in the culture medium in which the diesel was sole carbon source .The strain was Gram-negative, motive, rod and growed facultatively in the 0 to 18.5% NaCl. Based on its characters, the strain was identified as a member of the genus Aeromonas, but there were some differences between this strain and the described species of this genus in some biochemical features, suggesting that it could be a new species of the genus.

Objective To investigate the early clinical effects of percutaneous kyphoplasty in the treatment of age-related osteo-porotic vertebral compression fractures .Methods Retrospected 54 cases with osteoporotic verebral compression fractures were treated with PKP ,summarized early clinical effects and complications .analysis of preoperative and postoperative wound vertebral height average recovery rate ,Cobb Angle ,VAS scores and ADL scores .Results Operations in all the 54 cases were completed smoothly ,47 cases for 6 to 24 months follow-up(mean 13 .5 months) .postoperative pain in 31patients obtained remission immedi-ately ,1 week after operation ,12 cases with lower back pain and need the non-steroidal anti-inflammatory medications ,the symptoms remissed significantly or disappeared after 8 weeks postoperatively .At the last follow-up ,4 patients still had low back pain and need oral analgesics .Preoperative and postoperative wound vertebral height average recovery rate ,Cobb Angle ,VAS scores and ADL scores was statistically significant .Conclusion PKP is a minimally invasive ,effective and safe procedure that provides pain relief and stabilization of spinal stability and activities under the bed early ,and improves quality of life at the same time .Grasping the indi-cations Strictly and holding the surgical skills can be obtained clinical results efficiently and safely .

Adolescent ; Anti-Bacterial Agents ; therapeutic use ; Anti-Ulcer Agents ; therapeutic use ; Female ; Humans ; Penicillin G Procaine ; therapeutic use ; Stomach Ulcer ; drug therapy ; microbiology ; pathology ; Syphilis ; drug therapy ; microbiology ; pathology ; Syphilis Serodiagnosis ; methods ; Treponema pallidum ; isolation & purification

ObjectiveToinvestigatethecorrelationofobstructivesleepapnea(OSAS)andsilentbrain infarction (SBI) in elderly population. Methods A total of 1658 old subjects aged 60 in Beijing and Qingdao w ere screened. Polysomnography (PSG) w as used to conduct the diagnosis and grade of OSAS. MRI w as used to diagnose SBI. Results In al elderly subjects, the prevalences of OSAS and SBI w ere 32.1% and 22.4%. There w ere significant differences in the constituent ratio of the patients w ith hypertension and diabetes, as w el as apnea-hypopnea index (AHI), oxygen desaturation index (ODI), mean oxygen saturation and the low est oxygen saturation betw een the patients w ith OSAS of different severity and the control group. With the increased severity of OSAS, the incidence of SBI increased significantly. The incidences of patients w ith non-OSAS and mild, moderate and severe patients w ith OSAS w ere 13.2%, 30.5%, 43.5%, and 68.8%, respectively. There w as a significant difference betw een the 2 groups ( χ2 =13.365, P=0.004). Multivariable logistic regression analysis showed that hypertension (odds ratio [OR] 2.254, 95%confidence interval [CI] 1.325 to 8.347;P=0.002), diabetes melitus (OR 1.893, 95%CI1.471-8.432;P=0.003) and AHI ≥15 times/h (OR 3.106, 95%CI 1.583-12.571; P<0.001) were the independent risk factors for SBI in elderly population. Conclusions The incidence of OSAS w as higher in the elderly population aged over 60. The incidence of SBI in patients w ith OSAS w as significantly higher than that in patients w ith non-OSAS, and w ith the aggravation of OSAS, it show ed an increasing trend. Moderate to severe OSAS w as an independent risk factor for SBI in elderly population.

BACKGROUND: Intra-articular injection of hormone has been applied in the treatment of arthritis because it can alleviate arthralgia rapidly, which is accompanied commonly by progressive cartilage impairments. It is not clear if supplement of growth factor like insulin effect can play a protective role in articular chondrocytes.OBJECTIVE: To observe the effects of insulin or hydrocortisone alone and the combination on the proliferation of chondrocytes.DESIGN: Grouping comparative study, the effect of one medicine was analyzed by using one-factor analysis of variance, while the combined effect was analyzed with multi-factor analysis of variance.SETTING: Guangdong Institute of Trauma Sugery.MATERIALS: Articular cartilage from the knees of New Zealand white rabbits of 4 - 6 weeks old.METHODS: This study was carried out at Guangzhou Traumatic Research Institute from Feberary 2000 to May 2001. Chondrocytes were isolated from the knee joints of New Zealand white rabbits, digested with hyaluronidase,pancreatin and type Ⅱ collagenase and exposed to insulin, hydrocortisone or the combination of insulin and hydrocortisone of different dosage. They were divided into four groups:Control group ( without adding insulin and hydrocortisone), insulin group (0. 035,0. 35,3.5,35 mg/L subgroups), hydrocortisone group(1,5,10,50,100 mg/L subgroups) and insulin(0. 35 mg/L) combined with hydrocortisone(50 mg/L) group. Their influence on chondrocytes proliferation was observed with methyl thiazolyl tetrazolium(MTT) method.sulin.at the concentration of 0. 035 mg/L( P ＜ 0.01 ), reaching the maximum at could inhibit the proliferation of chondrocytes ( P ＜ 0.05 ), which became significant with increasing concentration and no viable chondrocytes could be exposed to 0 . 35 mg/L insulin combined with 50 mg/L hydrocortisone, the promoting effect of insulin was inhibited due to negative cooperation.CONCLUSION: Insulin at low concentration could enhance the proliferation of chondrocytes, but hydrocortisone displayed inhibiting effect on the growth of chondrocytes. The function of insulin was antagonized when combined with hydrocortisone.

BACKGROUND: Type Ⅱ collagen has been used as the carrier for chondrocyte transplantation in animal models, but whether type Ⅱ collagen may cause arthritis or mediate cytotoxicity remains unknown.OBJECTIVE: To detect the cellular immune functions of the New Zealand rabbits immunized by porcine type Ⅱ collagen.DESIGN: An exploratory comparative study based on the observations.SETTING: An institute of trauma surgery of a municipal hospital.MATERIALS: The study was conducted in the Institute of Trauma Surgery,Guangzhou Red Cross Hospital from August 1999 to February 2000. Six New Zealand rabbits, whose body mass ranged from 2.0 kg to 3.0 kg, were chosen of either gender.METHODS: The rabbits were immunized by porcine type Ⅱ collagen for 60days, during which the plasma was regularly taken for detection of type Ⅱ collagen antibody. On the 60th day, the peripheral blood as well as the spleens and lymph nodes were taken to separate the lymphocytes, which were subjected to secondary stimulation with type Ⅱ collagen in vitro to observe the reactive cell proliferation. The lymphocytes were randomly divided into two groups, and the first group was treated with phytohemagglutinin(PHA) of different concentrations to serve as the positive control, in which non-specific immunity was examined; The second group was treated with type Ⅱ collagen of different concentrations for examining specific immunity.peripheral blood lymphocytes of normal and immunized rabbits.RESULTS: On the 21st day, the titer of the antibody presented the first peak, and 40 days after the re-injection of the antigen the second peak appeared, which maintained for 20 days and then gradually descended. The lymphocytes of the normal rabbits proliferated in response to PHA stimulation but not to the first stimulation with the type Ⅱ collagen. The lymphocytes of the immunized rabbits exhibited significant proliferation upon stimulations with both PHA and type Ⅱ collagen. At the concentration of 25 mg/L, type Ⅱ collagen stimulation was sufficient to induce lymphocyte proliferation, the peak of which occurred when the collagen concentration reached 50 mg/L.CONCLUSION: Xenogenic type Ⅱ collagen at an adequate concentration may induce the increase of the type Ⅱ collagen antibody in immunized rabbits and proliferation of lymphocytes of the spleens and peripheral blood to cause cellular immune reaction and even immunological arthritis in relation to the transplantation.

Objective:The aim of this study was to assess the diagnostic accuracy of dual-source computed tomography(DSCT) in the evaluation of coronary artery disease(CAD).Methods:Fifty-two patients(44 male,8 female,mean age 70.59) with a high pre-test probability of CAD underwent DSCT coronary angiography and selective coronary angiography(SCA).Two physicians independently assessed the images of all coronary segments.Results:The overall sensitivity,specificity,positive and negative predictive value for evaluating CAD were 92.31%,99.82%,90.57%,and 99.32%,respectively.Conclusion:The result indicates that DSCT coronary angiography provides high diagnostic accuracy for assessment of CAD.And it is a better choice for CAD evaluation.

Objective To investigate the association between plasma Klotho protein level and lacunar cerebral infarction in the elderly.Methods Eighty eight patients with lacunar cerebral infarction aged over 60 years were selected as the observation group,and 90 age-and gender-matched elderly patients without lacunar infarction as the control group.The protein level of Klotho was tested by enzyme linked immunosorbent assay (ELISA).Klotho protein level was compared between the observation and control groups.The correlation between plasma Klotho level and lacunar infarction in elderly patients was analyzed.Results Compared with the control group,lacunar infarction group showed that Klotho protein level was decreased [(689.4±40.8) ng/L vs.(848.5±38.7) ng/L,P=0.009],and the proportion of patients with hypertension was increased (83.0％ vs.66.7％,P=0.04).There was no significant difference in age,gender,body mass index (BMI),dyslipidemia,diabetes mellitus and coronary heart disease between the two groups.The multivariate logistic regression analysis showed that the low plasma level of Klotho protein and hypertension were identified as the independent risk factors for Lacunar infarction (OR=3.325 and 2.413,P=0.003 and 0.021,respectively).Conclusions Klotho protein level may be associated with lacunar cerebral infarction in elderly people.Monitoring plasma Klotho protein level has an important clinical significance in the prevention,diagnosis and prognosis of lacunar cerebral infarction.