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.

Analysis of correlative factors of spinal cord posterior displacement after single door laminoplasty / 中国骨伤

OBJECTIVE@#To observe the open angle (OA), cervical curvature angle (CA), preoperative spinal cord compression rate(PSCR), postoperative spinal cord shift (PSCS) in patients with chronic compressive cervical myelopathy undergoing C3-7 single open laminoplasty, and to explore the possible mechanism and influencing factors of postoperative average spinal cord drift, so as to provide objective basis for predicting PSCS.@*METHODS@#From May 2012 to July 2016, 32 patients with multi-segmental chronic compressive cervical myelopathy who underwent single-door laminoplasty in our department were analyzed retrospectively, including 14 cases of cervical spondylotic myelopathy, 8 cases of developmental cervical spinal stenosis with cervical myelopathy, and 10 cases of ossification of posterior longitudinal ligament. The OA of cervical spine was measured on CT, the CA was measured on X-ray, the PSCR and PSCS were measured on MRI. The patients were divided into two groups according to PSCS(group A>=2.5 mm, group B0.1), and the partial regression coefficients of OA and PSCR were 0.113 and 0.059 respectively.@*CONCLUSIONS@#PSCS is the result of OA, CA and PSCR, among which PSCR has the most important influence, OA is the second, CA is the least. PSCS can be predicted by 0.059×OA+0.113×PSCR-2.266 equation, which provides a theoretical basis for preoperative evaluation of spinal cord decompression after surgery.

Analysis of influencing factors the postoperative axial symptoms of cervical single open-door laminoplasty / 中国骨伤

OBJECTIVE@#To explore the influencing factors and possible mechanism of axial symptoms(AS) after C₃-C₇ single open-door laminoplasty in patients with chronic compression cervical myelopathy.@*METHODS@#The clinical data of 32 patients with multi-segment chronic compression cervical cord disease treated by C₃-C₇ single open-door laminectomy from May 2012 to July 2016 were retrospectively analyzed. Including cervical spondylotic myelopathy of 14 cases, developmental cervical stenosis complicated with cervical myelopathy of 8 cases, ossification of posterior longitudinal ligament(OPLL) of 10 cases. There were 17 males and 15 females, aged from 47 to 82 years old with an average of 57.46 year, the course of disease was 5 to 35 months with an average of 22.4 months. The opening angle(OA), cervical curvature angle(CA), preoperative spinal cord compression rate(PSCR) and postoperative spinal cord shift (PSCS) were recorded. After 2 weeks of surgery, determining whether occurred an AS condition according to the AS assessment criteria, the patients were divided into a axial symptom group and a non-axial symptom group, the general data and imaging parameters of the two groups were compared and the factors that may be postoperative AS were analyzed by binary Logistic regression analysis.@*RESULTS@#At 2 weeks after operation, 13 patients occurred AS. There was no significant difference in gender, age and course of disease between axial symptom group and a non-axial symptom group (>0.05). In axial symptom group, OA was(36.76±9.35)°, CA was(11.53±4.36)°, PSCR was(27.83±1.72)%, PSCS was (3.17±0.81) mm, while in non-axial symptom group, above items were (33.03±10.52)°, (7.71±4.73)°, (25.16±3.59)%, (2.43±0.95) mm, respectively, there was significant difference in CA, PSCR, PSCS between two groups(0.05). The results of the binary Logistic regression analysis of 3 parameters(OA, PSCR, PSCS) and AS showed OA and PSCR were eliminated in dependent variables, and the partial regression coefficient of PSCR was 0.311, and =0.031.@*CONCLUSIONS@#CA, PSCR, and PSCS are related influencing factors of AS, and PSCS is a high risk factor for AS. C₄,₅ nerve traction caused by posterior spinal movement, postoperative dural self-expansion causes greater traction of the spinal cord, excessive deformation of the cervical spinal cord causes autonomic nerve damage or necrosis that dominates blood vessels may be the pathogenesis of AS, but this is only a theoretical inference, and further improved experiment is necessary to verify it in the future.

Research and progress on diagnosis and treatment of intervertebral space infection / 中国骨伤

As the disc surgery were extensively developed, the incidence of intervertebral space infection was significantly increased. Due to a lack of specificity, early diagnosis is difficult and it is prone to misdiagnose. Intervertebral disc puncture sampling microorganism culture is a gold standard of antibiotic selection, but the positive detection rate needs to be improved. At present, different medical institutions have different opinious in epidemiology, treatment experiences, the choice of antibiotic treatment, the course of treatment and the way of operation. In recent years, magnetic resonance imaging, fluorine deoxidization glucose positron emission computed tomography scanning, the imaging application mediated percutaneous intervertebral disc, spinal puncture percutaneous endoscopic debridement and lavage drainage and percutaneous internal fixation combined with anterior posterior incision provide more choices for early diagnosis and treatment. Intervertebral infection should attract more attention to the prevention, early diagnosis, early specific pathogens. Doctors' experience and patients' actual situation should be considered when choosing a appropriate treatment. During the treatment, we should be closely monitored laboratory indexes and timely adjust plan of the treatment, and shorten the treatment time and prevent other complications through the auxiliary treatment.