High salt-induced weakness of anti-oxidative function of natriuretic peptide receptor-C and podocyte damage in the kidneys of Dahl rats / 中华医学杂志(英文版)

BACKGROUND@#Atrial natriuretic peptide (ANP) and its natriuretic peptide receptors A (NPR-A) and C (NPR-C) are involved in the regulation of physiological and pathophysiological process of blood pressure. The present study aimed to determine the role of NPR-C in the development of salt-sensitive hypertension.@*METHODS@#The Dahl salt-sensitive (DS) and salt-resistant (DR) rats were used in this study. Animals were matched according to their age and weight, and then placed on either a high-salt (HS, 8%) or a normal-salt (NS, 0.4%) diet for 6 weeks randomly using random number table. The systolic blood pressure (SBP), plasmatic sodium concentration (PLNa), urinary sodium excretion (UVNa), and serum creatinine concentration (Scr) were measured. The concentration of ANP in blood and tissues (heart and kidney) was detected by enzyme-linked immunosorbent assay. The expression of ANP, NPR-A, and NPR-C in kidney was evaluated with western blot analysis. Regarding renal redox state, the concentration changes in malondialdehyde (MDA), lipofuscin, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox), and nitric oxide synthase (NOS) in kidney were detected by a spectrophotometric method. The kidney damage was evaluated using pathological techniques and the succinodehydrogenase (SDHase) examination. Furthermore, after an intra-peritoneal injection of C-atrial natriuretic peptide (ANP)4-23 (C-ANP4-23), an NPR-C receptor agonist, the SBP, biochemical values in blood and urine, and renal redox state were evaluated. The paired Student's t test and analysis of variance followed by the Bonferroni test were performed for statistical analyses of the comparisons between two groups and multiple groups, respectively.@*RESULTS@#The baseline SBP in all groups was within the normal range. At the end of the 6-week experiment, HS diet significantly increased the SBP in DS rats from 116.63 ± 2.90 mmHg to 162.25 ± 2.15 mmHg (t = -10.213, P  0.05). The significant increase of PLNa, UVNa, and Scr related to an HS diet was found in both DS and DR rats (all P < 0.05). However, significant changes in the concentration (t = -21.915, P < 0.001) and expression of renal ANP (t = -3.566, P = 0.016) and the expression of renal NPR-C (t = 5.864, P = 0.002) were only observed in DS hypertensive rats. The significantly higher desmin immunochemical staining score (t = -5.715, P = 0.005) and mitochondrial injury score (t = -6.325, P = 0.003) accompanied by the lower SDHase concentration (t = 3.972, P = 0.017) revealed mitochondrial pathologic abnormalities in podocytes in DS rats with an HS diet. The distinct increases of MDA (t = -4.685, P = 0.009), lipofuscin (t = -8.195, P = 0.001), and Nox (t = -12.733, P < 0.001) but not NOS (t = -0.328, P = 0.764) in kidneys were also found in DS hypertensive rats. C-ANP4-23 treatment significantly decreased the SBP induced by HS in DS rats (P < 0.05), which was still higher than NS groups with the vehicle or C-ANP4-23 treatment (P < 0.05). Moreover, the HS-induced increase of MDA, lipofuscin, Nox concentrations, and Nox4 expression in DS rats was significantly attenuated by C-ANP4-23 treatment as compared with those with HS diet and vehicle injection (all P < 0.05).@*CONCLUSIONS@#The results indicated that the renal NPR-C might be involved in the salt-sensitive hypertension through the damage of mitochondria in podocytes and the reduction of the anti-oxidative function. Hence, C-ANP4-23 might serve as a therapeutic agent in treating salt-sensitive hypertension.

Advances in research of fecal bacteria transplantation in inflammatory bowel disease / 医学研究生学报

Inflammatory bowel disease (IBD) is a chronic, nonspecific, inflammatory bowel disease that has not been completely elucidated yet. In recent years, the role of gut flora in the pathogenesis and prognosis of IBD has drawn more and more attention. Fecal Bacterial Transplantation (FMT) referred to transplanting healthy human gut flora into the patient's gastrointestinal tract and reconstitutes a functioning gut flora. Many studies have shown that FMT is effective in treatment of IBD. This brings new hope to IBD patients with poor clinical drug treatment. The applications and precautions of FMT in IBD are reviewed.

Three-dimensional finite element analysis of the cantilever fixed bridge supported by implants with different shapes / 中国组织工程研究

BACKGROUND: The shape of the implant exerts an effect on its biomechanics. At present, the research of implant-supported fixed partial denture with cantilever extension mainly focuses on the same shape, and little is reported on the comparison and analysis of implant-supported fixed partial denture with cantilever extension supported by different shape implants.OBJECTIVE: To compare the biomechanical behaviors of cantilever fixed bridges which were supported by three different implants, including cylindrical implant, tapered implant, expandable implant, in the mandibular posterior region with the help of three-dimensional finite element analysis. METHODS: The three-dimensional finite element models of the cantilever fixed bridges which were supported by cylindrical implant, tapered implant and expandable implant and their surrounding tissue in the mandibular posterior region were established were established. The force of 300 N was applied to the cantilever fixed bridges with axial 90° and buccolingual 45° to evaluate the maximum von Mises stress (Max EQV stress) of cortical bone and cancellous bone and the maximum displacement in implant-abutment complex.RESULTS AND CONCLUSION: Under axial and buccolingual loads, the Max EQV stress in the cortical bone was higher than that in the cancellous bone. The cantilever fixed bridge which was supported by expandable implant had the lowest Max EQV stress in the cortical bone, especially under axial load, and exhibited the highest Max EQV stress in the cancellous bone. The cantilever fixed bridges supported by three different implants showed an increase in the Max EQV stress of the cortical bone and cancellous bone and the maximum displacement in implant-abutment complex under buccolingual load. The cantilever fixed bridge which was supported by expandable implant had the minimum maximum displacement in the buccolingual direction. To conclude, the cantilever fixed bridge which is supported by expandable implant has best stability.

Three-dimensional finite element analysis of the cantilever fixed bridge supported by implants with different shapes / 中国组织工程研究

BACKGROUND: The shape of the implant exerts an effect on its biomechanics. At present, the research of implant-supported fixed partial denture with cantilever extension mainly focuses on the same shape, and little is reported on the comparison and analysis of implant-supported fixed partial denture with cantilever extension supported by different shape implants.OBJECTIVE: To compare the biomechanical behaviors of cantilever fixed bridges which were supported by three different implants, including cylindrical implant, tapered implant, expandable implant, in the mandibular posterior region with the help of three-dimensional finite element analysis. METHODS: The three-dimensional finite element models of the cantilever fixed bridges which were supported by cylindrical implant, tapered implant and expandable implant and their surrounding tissue in the mandibular posterior region were established were established. The force of 300 N was applied to the cantilever fixed bridges with axial 90° and buccolingual 45° to evaluate the maximum von Mises stress (Max EQV stress) of cortical bone and cancellous bone and the maximum displacement in implant-abutment complex.RESULTS AND CONCLUSION: Under axial and buccolingual loads, the Max EQV stress in the cortical bone was higher than that in the cancellous bone. The cantilever fixed bridge which was supported by expandable implant had the lowest Max EQV stress in the cortical bone, especially under axial load, and exhibited the highest Max EQV stress in the cancellous bone. The cantilever fixed bridges supported by three different implants showed an increase in the Max EQV stress of the cortical bone and cancellous bone and the maximum displacement in implant-abutment complex under buccolingual load. The cantilever fixed bridge which was supported by expandable implant had the minimum maximum displacement in the buccolingual direction. To conclude, the cantilever fixed bridge which is supported by expandable implant has best stability.

Effect of factors on pepsin and trypsin fibrinolytic activity and deactivation of fibrinolytic activity / 中草药

Objective: To investigate the method for study on the effect of factors on pepsin and trypsin fibrinolytic activity and deactivation of fibrinolytic activity and to eliminate the interference of pepsin and trypsin on the detection of crude protein fibrinolytic activity of Armadillidium vulgare (porcellio plasmin) in order to obtain the proteins or peptides which have the smaller molecular weight but higher titer during the pepsin and trypsin degradation. Methods: To study the effect of pepsin and trypsin deactivation on pH value, temperature, metal ions, enzyme inhibitor, surfactant, and responsing fibrinolytic by fiber fibrin plate assay. The better enzyme deactivation process was obtained and used for studying the effect on the fibrinolytic activity of urokinase, lumbrokinase, and porcellio plasmin. Results: All the pH value, temperature, metal ions, enzyme inhibitor, and surfactant have had an impact on pepsin and trypsin fibrinolytic activity. Among them the optimum deactivation of pepsin was pH 6.0-8.0, while the optimum deactivation of trypsin was mixed preparation with TLCK at the concentration of 25 mg/mL and EDTA at the concentration of 1 mmol/L. Conclusion: This study has obtained the better enzyme deactivation process which could be used for the detection of fibrinolytic activity of pepsin and trypsin degradation product by fiber fibrin plate assay, the operation is simple, and the repeatability and stability are good.

Comparison of low-dose sequences of dual-source CT and echocardiography for preoperative evaluation of aortic valve disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Accurate evaluation of coronary artery, aortic valve annulus diameter (AVAD), and cardiac function in patients with aortic valve disease is of great significance for surgical strategy. In this study, we explored the preoperative evaluation of low-dose sequence (MinDose sequence) scan of dual-source CT (DSCT) for those patients.</p><p><b>METHODS</b>Forty patients suspected for aortic valve disease (the experimental group) underwent MinDose sequence of DSCT to observe coronary artery, AVAD, and left ventricular ejection fraction (LVEF). Another 33 subjects suspected for coronary artery disease (the control group) underwent conventional retrospective electrocardiographically-gated sequence of DSCT. Two-dimensional transthoracic echocardiography (2D-TTE) and four-dimensional transthoracic echocardiography (4D-TTE) were applied in the experimental group to measure AVAD and LVEF and compared with MinDose-DSCT.</p><p><b>RESULTS</b>There was a strong correlation between LVEFs measured by 2D-TTE and MinDose-DSCT (r = 0.87, P < 0.01), as well as between 4D-TTE and MinDose-DSCT (r = 0.90, P < 0.01). AVAD measured by MinDose-DSCT was in good agreement with corresponding measurements by 2D-TTE (r = 0.90, P < 0.01). The effective dose in the experimental group was 63.54% lower than that in the control group.</p><p><b>CONCLUSIONS</b>MinDose sequence of DSCT with a low radiation dose serving as a one-stop preoperative evaluation makes effective assessment of the coronary artery, AVAD, and LVEF for patients with aortic valve disease.</p>

Clinical analysis for 70 sinus of valsalva aneurysm / 中华外科杂志

<p><b>OBJECTIVE</b>To review retrospectively the experience of surgical repair of sinus of valsalva aneurysm (SVA) in 70 patients.</p><p><b>METHODS</b>Between September, 1988 and October, 2003, Seventy patients with SVA underwent surgical repair by the aid of general anesthesia and cardiopulmonary bypass, comprised 1.4% (70/4960) of all open-heart operation. Forty-five were male and 25 female. Age ranged from 3 to 69 years old [mean (29 +/- 15) years]. The aneurysms ruptured into the right ventricle in 46 patients, right atrium in 23 and left ventricle in 1 respectively. The aneurysms originated from right and noncoronary sinus in 61 patients (87%) and 9 patients (13%) respectively. The most common associated cardiovascular lesions were ventricular septal defect (VSD, n = 34) and aortic valve incompetence (n = 21). Repairs were achieved through an incision in right atriotomy, right ventriculotomy or aortotomy only or both aortotomy and right atriotomy (or right ventriculotomy). The defects in the sinus of valsalva was repaired with either direct sutures (n = 43) or a patch (n = 27). The aortic valve was replaced in 6 patients.</p><p><b>RESULTS</b>There were no deaths in early time after repair. Postoperative hospital stay was 8 approximately 33 days [mean +/- standard deviation, (14.3 +/- 6.4) days] before 1997 and 6 approximately 15 days [mean +/- standard deviation, (9.1 +/- 2.6) days] after 1997 respectively. Complications included infection (n = 4), hemorrhage (n = 4), pneumothorax (n = 1), arrhythmia (n = 4) and residual shunt (n = 1) of VSD. Fifty-three (76%) patients (2 months approximately 13 years) were followed-up [mean +/- standard deviation, (6.6 +/- 3.8) years]. All patients survived except that one died of rupture of dissecting aortic aneurysm 7 years after operation.</p><p><b>CONCLUSIONS</b>The ruptured sinus of valsalva aneurysm and unruptured sinus of valsalva aneurysm with ventricle septal defect or(and) aortic valve regurgitation should be repaired surgically as soon as the diagnosis was confirmed. Long-term results are associated with preoperative aortic valve regurgitation.</p>