2006年 · 第119卷第10期

Abstract：Background Using tissue Doppler imaging and conventional echocardiographic technique, we examined the cardiac function and synchronicity in individuals with isolated right bundle branch block (RBBB) or left bundle branch block (LBBB) and assessed the relationship between QRS duration and synchronicity.Methods Subjects with isolated RBBB (n=20), LBBB (n=10) and normal controls (n=20) were studied with conventional echocardiography and tissue Doppler imaging. The difference between aortic and pulmonary preejection intervals was defined as interventricular delay. Parameters in septum and lateral wall were measured using tissue Doppler imaging, including peak sustained systolic velocity (SM), peak early (EM) and late (AM)diastolic velocities as well as time to peak velocities (Ts, TE and TA).Results Subjects with LBBB had lower SM and longer Ts than did the RBBB and control groups (P＜0.05,P＜0.001 respectively). A significant difference was observed in EM, being the lowest in the LBBB and the highest in the control group (P＜0.05). Moreover, TE was longer in the LBBB group compared with the other two groups (P＜0.001). Both AM and TA were similar among three groups (P＞0.05). In the bundle branch block groups, one ventricle lagged about 40 ms behind the other. A significant correlation was found between interventricular delay and QRS duration (r =0.713, P＜0.001).Conclusions Cardiac ventricles were not well synchronized with one ventricle lagging about 40 ms behind the other in subjects with LBBB or RBBB, even though only LBBB group showed barely perceptible, impaired cardiac function. In addition, QRS duration and cardiac asynchronicity were positively correlated。

Abstract：Background The relationship between signal transduction and tumors has become one of the foci in cancer research. Signal transducer and activator of the transcription 6 (STAT6) signaling pathway is found to be activated in some cancer cells. But the function of the pathway in cancer cells is unknown. This study was undertaken to investigate the effect of the Stat6 signaling pathway on apoptosis in human colon cancer cells (HT-29 cells) and the possible mechanism of Stat6 by RNA interference techniques.Methods Four eukaryotic expression plasmid vectors of short hairpin RNA (shRNA) specific for the STAT6gene were designed and generated by molecular biological technology. The plasmid vectors were transfected into HT-29 cells by cation liposomes to block the Stat6 signaling pathway. The expressions of STAT6 mRNA and phosph-Stat6 protein were detected by the reverse transcriptase polymerase chain reaction (RT-PCR) method and flow cytometry respectively to screen the most effective shRNA at 72 hours after transfection. The apoptosis condition of the cells in which the expression of the STAT6 gene had been interfered was analyzed by flow cytometry and confocal microscopy. Both mRNA and protein expression of B cell lymphoma-2 (Bcl-2) and Bax were detected by RT-PCR and western blotting.Results Two effective eukaryotic expression plasmid vectors of shRNA specific for the STAT6 gene were generated successfully. One can reduce the expression of the STAT6 gene by 82.4% and the other by 56.8%(P＜0.01). The apoptotic rate of colon cancer cells in which STAT6 gene expression had been interfered was significantly higher than that in controlled colon cancer cells (P＜0.01). In the cells in which the Stat6 signaling pathway was blocked, the levels of mRNA and protein Bcl-2 were significantly decreased, whereas those of Bax were significantly increased (P＜0.01).Conclusions The Stat6 signaling pathway can inhibit apoptosis in human colon cancer cells. The subsequent disorder of Bcl-2/Bax expression may play an important part in that process. The STAT6 gene may serve as a potential target in cancer therapy。

Abstract：Background Post and post-core systems are used to restore extensively damaged teeth. Among these systems,cast alloy post and core, prefabricated threaded alloy post and prefabricated simple alloy post are most frequently applied in China nowadays. In Europe and North America a combined application of the fiber post, resin-core and crown has been applied to restore seriously destructed teeth with satisfactory results in recent years. This study was intended to evaluate the clinical effect of carbon fiber post system on restoration of child anterior tooth defect after root canal therapy, based on 3- 5 years' observation.Methods One hundred and six children with incompletely established occlusion were observed and followed for an average of 42 months (ranging from 36 to 60 months). Eighty-five upper teeth and forty-one lower teeth were restored with carbon fiber post system and composite jacket crown. Periodic check-up was conducted for periodontal condition and restoration effect.Results One hundred and twenty-one (96.2%) restorations were successful. Four jacket crowns (3.0%) were lost. One tooth (0.8%) had slight gingival inflammation. Tooth root or post fracture and gingival stain were not observed. X-ray showed there was no obvious change in aspects including the width of periodontal membrane,the density of alveolar bone and the height of alveolar ridge crest.Conclusions Carbon-fiber post system can satisfy the clinical requirements of young patients who have residual anterior crown and root caused by trauma or caries, and have incomplete occlusion and have completed root canal therapy. This system helps realize good esthetic result for patients and easy practice for dentists.Carbon fiber post is safe and convenient, especially for sick children。

Abstract：Background Excessive deposition of extracellular matrix (ECM) in the kidney is the hallmark of diabetic nephropathy. Increased matrix synthesis has been well documented but the effects of diabetes on degradative pathways, particularly in the in vivo setting. The renal protective effect of these pathways on matrix accumulation has not been fully elucidated. The present study was understaken to investigate the activity of matrix metalloproteinase-2 (MMP-2), the expression of MMP-2 and tissue inhibitor of metalloproteinase-2 (TIMP-2) in kidney tissues of diabetic rats, and to explore the degradative pathway of type Ⅳ collagen (Ⅳ-C) and the renal protective effects of ACE inhibition-benazepril.Methods Twenty-four healthy male Wistar rats were divided randomly into normal control group (NC group),untreated diabetes mellitus group (DM group), and diabetes mellitus group treated with benazepril (DL group).The rat model of diabetes mellitus was induced by intraperitoneal injection of streptozocin (60 mg/kg). After the volume of water was given to the other two groups. At the end of 12 weeks, renal function was evaluated with 24-hour urinary protein (Upro), clearance of creatinine (Ccr), and blood urea nitrogen (BUN). MMP-2 activity was determined by gelatin zymography. The levels of MMP-2,TIMP-2 and collagen Ⅳ (Ⅳ-C) protein in the kidney tissue were assessed by immunohistochemistry. The gene expression of MMP-2 and TIMP-2 was measured by reverse transcription polymerase chain reaction (RT-PCR).Results The levels of BUN, Upro and Ccr in the DM group were higher than those in the NC group. In the DM group, the mRNA, enzymatic activity and proteins of MMP-2 decreased, but the expressions of Ⅳ-C and TIMP-2 increased. All diabetes-associated changes in renal function and MMP/TIMP were attenuated after benazepril treatment with reduced Ⅳ-C accumulation.Conclusions The changes of MMP-2 and TIMP-2 expressions in kidney tissues of diabetes rats may contribute to the occurrence and progression of diabetic nephropathy. Benazepril could exert protective effects on diabetic nephropathy, owing to the upregulation of MMP-2 and downregulation of TIMP-2 expressions, which further inhibits the excessive deposition of extracellular matrix in the glomerulus。

Abstract：Background Advances in treatment have greatly reduced the risk of blindness from this disease, but because diabetes is so common, diabetic retinopathy remains an important problem. The purpose of this study is to investigate the risk factors of diabetic retinopathy (DR) in Chinese type 2 diabetic patients.Methods Totally 746 type 2 diabetic patients were selected for biochemical and clinical characteristics test and examined by the retina-camera for diabetic retinopathy and the average age was 55.9 years old.Results A total of 526 patients was classified as non-DR, 159 patients as non-proliferative-DR and 61 patients as proliferative-DR. Duration of diabetes [(66.09±72.51) months vs (143.71 ±93.27) months vs (174.30±81.91)months, P=0.00], systolic blood pressure [(131.95±47.20) mmHg vs (138.71 ±21.36) mmHg vs (147.58±24.10)mmHg, P=0.01], urine albumin [(32.79± 122.29) mg/L vs (190.96±455.65) mg/L vs (362.00±552.51) mg/L,P=0.00], glycated hemoglobin (HbA1c) [(8.68 ± 2.26)% vs (9.42±1.84)% vs (9.42±1.96)%, P=0.04],C-reactive protein (CRP) [(3.19±7.37) mg/L vs (6.36± 23.59) mg/L vs (3.02±4.34) mg/L, P=0.03],high-density lipoprotein cholesterol (HDL-C) [(1.23±0.37) mmol/L vs (1.33±0.35) mmol/L vs (1.24±0.33)mmol/L, P=0.01], uric acid (UA) [(288.51 ±90.85) mmol/L vs (300.29±101.98) mmol/L vs (337.57±115.09)mmol/L, P=0.00], creatinine (CREA) [(84.22±16.31) μmol/L vs (89.35±27.45) μmol/L vs (103.28±48.64)μmol/L, P=0.00], blood urine nitrogen (BUN) [(5.62± 1.62) mmol/L vs (6.55±2.74) mmol/L vs (8.11±3.60)mmol/L, P=0.00] were statistically different among the three groups. Logistic regression analysis showed that diabetic duration and urine albumin were two independent risk factors of DR (the OR values were 1.010 and 1.003 respectively).Conclusions Diabetic duration and urine albumin are two independent risk factors of diabetic retinopathy in elderly type 2 diabetic patients。

Abstract：Background Solar ultraviolet (UV) irradiation induces the production of matrix metalloproteinases (MMPs) by activating cellular signalling transduction pathways. MMPs are responsible for the degradation and/or inhibition of synthesis of collagenous extracellular matrix in connective tissues. We mimicked the action of environmental ultraviolet on skin and investigated the effects of UVB-irradiated human keratinocytes HaCaT and IL-1α on mitogen activated protein (MAP) kinase activation, c-Jun and c-Fos (AP-1 is composed of Jun and Fos proteins)mRNA expression and MMP-1 production in UVA-irradiated dermal fibroblasts.Methods Following UVA irradiation, the culture medium of fibroblasts was replaced by culture medium from UVB-irradiated HaCaT, or replaced by the complete culture medium with interleukin (IL)-1α. MAP kinase activity expression in fibroblasts was detected by Western blot. c-Jun and c-Fos mRNA expressions were determined by reverse transcriptional polymerase chain reaction (RT-PCR); MMP-1 production in culture medium was detected by enzyme-linked immunosorbent assay (ELISA).Results Culture medium from UVB-irradiated keratinocytes increased MAP kinase activity and c-Jun mRNA expression in UVA-irradiated fibroblasts. IL-1α increased MAP kinase activity and c-Jun mRNA expression,IL-1 α also increased c-Fos mRNA expression. Both culture media from UVB-irradiated human keratinocytes and externally applied IL-1 α increased MMP-1 production in UVA-irradiated fibroblasts.Conclusions UVB-irradiated keratinocytes and IL-1α indirectly promote MMP-1 production in UVA-irradiated fibroblasts by increasing MAP kinase/AP-1 activity. IL-1 may play an important role in the paracrine activation and dermal collagen excessive degradation leading to skin photoaging。

Abstract：Background Cardiomyocyte transplantation for the therapy of myocardial ischaemia is being paid close attention. However, how the microenvironment controls the differentiation of transplanted bone marrow stromal cells (BMSCs) is unknown. Endothelin-1 (ET-1), a cytokine, increases during myocardial infarction, but it is not known whether ET-1 is responsible for the fate of transplanted BMSCs. In the present study, we investigated the effects of ET-1 on differentiation and maturation of induced rabbit BMSCs, in vitro, to elucidate the cellular biological mechanisms.Methods The proliferation of BMSCs isolated from femur of rabbits was induced by ET-1 only, by 5-azacytidine (5-aza) or ET-1 combined with 5-aza. After 4 weeks of induced culturing, the differentiation rate and the diameter of induced myocyte like cells were estimated and the expressions of GATA-4 protein and phosphorylation level were assayed by Western-blot, RT-PCR analysis of β-myosin heavy chain (MHC). mRNA expression, levels of troponin-Ⅰ by immunohistochemical staining and ultrastructure of induce-cultured BMSCs were also determined.Results By induction with ET-1 and 5-aza, mean cell diameter of induced BMSCs was larger than induced with 5-aza [(6.26±0.22) μm cf (5.29±0.19) μm] (P ＜ 0.001). There was no difference in rate of differentiation of myocyte like cells between the groups induced with 5-aza and ET-1 combined with 5-aza [(29.82±0.23) % cf (29.94±0.18) %] (P ＞ 0.05). The expressions of GATA-4 protein and phosphorylation were enhanced significantly in groups induced with ET-1 combined with 5-aza (P ＜ 0.05). In the group induced with ET-1combined with 5-aza, expression of β-MHC mRNA was higher than control [(0.122 ± 0.008) cf (0.022 ± 0.003)](P ＜0.01), and more troponin-Ⅰ positive cells were also detected in this group. Differentiated BMSCs showed formations of myofilaments and primitive sarcomere, i.e., morphological characteristics of myocyte like cells.Conclusions This study suggests that induced culturing of BMSCs by ET-1 combined with 5-aza can express cardiomyocytic characteristics whereas ET-1 alone could not induce BMSCs to differentiate to myocyte like cells.ET-1 upregulates the expression of GATA-4 protein and phosphorylation level of induced BMSCs, and rapidly promotes the differentiation and maturation of myocyte like cells from BMSCs。

Abstract：Background Laparoscopic dismembered pyeloplasty with less trauma than open surgery is commonly performed for ureteropelvic junction obstruction despite a longer operating time and a long learning curve. We describe in this paper a new technique, which combines laparoscopic and open procedure in dismembered pyeloplasty, that we have developed in 51 patients and achieved excellent results.Methods The surgical procedure can be divided into two steps: laparoscopic dissection of the renal pelvis and proximal ureter transperitoneally; then accomplishing the pyeloplasty through the extended port incision above the ureteropelvic junction as in open surgery.Results All 51 operations were successful without conversion to open surgery. No intraoperative complications were observed. The operating time was 40 minutes to 90 minutes with an average of 57.5 minutes. The estimated blood loss was 15 ml to 30 ml with an average of 21.2 ml. Aberrant artery vessel and primary stricture as the cause of ureteropelvic junction obstruction was noted in 2 and 49 patients, respectively. Thirty-nine patients had fever to differing extents in the 4 days postoperation and no severe infection was observed. Four patients had urinary leakage with their drains being retained for 6 days, 6 days, 5 days or 8 days after the operation. The mean followup was 10.8 months (range 3 months to 36 months). The followup showed good results with symptom resolution in all the patients. Renal ultrasonography demonstrated that the average separation of the collecting systems decreased from preoperative 2.7 cm (range 2.0 cm to 4.7 cm) to postoperative 1.5 cm (range 1.0 cm to 2.3 cm). Excretory urography at 3 months postoperatively showed improved drainage. Of the 51 patients, 35underwent two or more excretory urograms, demonstrating stable renal function, improved drainage and no evidence of recurrent obstruction. At the last followup visit, each patient was doing well.Conclusions Combination of laparoscopic and open procedure in dismembered pyeloplasty offers a simpler,timesaving method in a minimally invasive fashion with low morbidity for patients with ureteropelvic junction obstruction. Ensuring quality of repair, the method provides a minimally invasive alternative with good results. It is worth future clinical application。

Photodynamic therapy (PDT) is a relatively new treatment modality. Clinical PDT procedure involves the administration of a photosensitizer followed by local illumination with visible light of a specific wavelength. In the presence of molecule oxygen, the light illumination of photosensitizer can lead to a series of photochemical reactions and consequently generate a variety of cytotoxic species.The nature, location and quantity of PDT-induced cytotoxic species and the sensitivity of the target cells determine the outcome of a PDT treatment.Since the first government approval of photosensitizer Photofrin was granted, for the treatment of bladder cancer in Canada in 1993,1 the utilization of PDT in the treatment of malignant and non-malignant diseases has increased significantly due to the improvement in photosensitizers and light applicators. Several similar photosensitizers have been developed and utilization in China since the 1980s.2

Hemorrhagic shock is a common clinical emergency case. Successful treatment is usually accomplished by surgical control of hemorrhage and restoration of tissue perfusion. The fluid resuscitation method in the presurgical care of the hypotensive trauma patients is controversial.Current guidelines for presurgical treatment of patients with hemorrhagic shock recommend rapid volume resuscitation to normal blood pressure as quickly as possible. The practice is controversial because aggressive restoration of intravascular volume and rapid increase of blood pressure before securing hemostasis may exacerbate hemorrhage and worsen outcome. Controlled fluid resuscitation allows pre-hospital treatment to work with compensatory mechanisms. The concept is to restore some intravascular fluid while respecting hemostatic mechanisms. Such a scheme would balance the mutually exclusive processes of tissue perfusion and hemostasis。

Postresuscitation myocardial dysfunction is reversible heart failure and B-type natriuretic peptide (BNP) is a biochemical marker of ventricular disorders secreted from ventricle, which can be used to assess the status of left ventricular function.1-3This study investigated the effect of β-adrenergic blocker on concentration of BNP and cardiac function after cardiopulmonary resuscitation in rabbits。

Emodin is an important component of rhubarb, a traditional Chinese herb. Previous studies in vitro showed that emodin inhibited the proliferation of human vascular smooth muscle cells,1 indicating the possible inhibitive effect of emodin on atherosclerosis. The present research evaluated the effect of emodin on the formation of atherosclerotic lesion induced by high cholesterol and fat diet in rabbits and the mechanism of this effect。

Cytomegalovirus (CMV) infection is a major and often deadly complication of haematopoietic stem cell (HSC) transplantation.1 Successful preemptive CMV therapy in transplant patients depends on the availability of sensitive, specific, and timely diagnostic tests for CMV infections.2 The pp65antigenemia assay has been used for this purposewith considerable success but has disadvantages of being time-consuming and labor-intensive.3 Recently,commercial quantitative polymerase chain reaction (PCR) methods based on TaqMan technique have become available and proven to be useful in the diagnosis of microbial infection as well as the determination of viral load.4 In this study, we developed a fluorescent-based quantitative real-time PCR (RT-FQ PCR) assay using TaqMan chemistry for rapid and quantitative detection of CMV DNA and assessed its clinic value for monitoring the reinfection of CMV in patients after HSC transplantion。

Since November 2002, an infectious disease with unknown cause occurred in China and many countries had been involved. Cases were reported in 28 countries and more than 5050 individuals had been infected.1 Lung is the most frequently involved organ and can be fatal in severe cases. At the end of February 2003, it was defined as Severe Acute Respiratory Syndrome (SARS) by World Health Organization. China had a SARS epidemic in the spring of 2003. More than 1000 patients were infected and some patients died of respiratory failure.Finally, a new variant of coronavirus was suspected to be the pathogen although the pathogenesis was still unclear. Since it is a new disease and we have very limited knowledge about its clinical sequela, we followed the survived patients closely in order to understand it in depth. During the follow up, we discovered an interesting patient who was finally diagnosed as fibromyalgia. We report this case herein to share our experience with clinicians who may see patients with SARS or fibromyalgia。

Rupture of isolated hypogastric artery aneurysm (HAA) is rarely encountered and is associated with a high mortality rate. Conventional surgery can not achieve distal control easily and may cause substantial blood loss, yielding high operative morbidity and mortality. On March 17, 2005, we treated a patient with such a disease successfully by using endovascular stent-grafting combined with transcatheter embolization。