Significance of sacroiliac joint aerocele in diagnosis of ankylosing spondylitis

To explore the significance of sacroiliac joint aerocele in the diagnosis of ankylosing spondylitis, the data of 196 patients with ankylosing spondylitis (AS) were collected during December of 2008 to May of 2009. And 50 patients with osteoarthritis (OA), 15 patients with sclerosing osteitis (SO) and 47 patients with sacroiliac joint tumors were investigated as the control groups. The feature of sacroiliac joint aerocele in computed tomography (CT) images was observed carefully. In AS group there were 130 patients (66.3%) diagnosed as AS according to CT results, and 32 of them (24.6%) were observed with aerocele within sacroiliac joint cavity, majority of whom were earlier AS patients with slight bone destruction. Other 66 patients were diagnosed as early AS according to magnetic resonance imaging (MRI) and ultrasonography. CT examination showed that the 66 patients did not have apparent bone destruction, of whom, 26 (39.4%) patients had aerocele within sacroiliac joint cavity. Among the control groups of 15 (15/50, 30.0%) patients with OA, 5 (5/15, 33.3%) patients with SO were observed sacroiliac joint aerocele. The 47 patients with sacroiliac joint tumors were observed with bone or cartilage destruction, but without signs of sacroiliac joint aerocele. The sacroiliac joint aerocele in CT images of AS patients usually appeared as spots, streaks, small or larger round blocks, and it often happened in patients with earlier stage of diseases. Sacroiliac joint aerocele may be useful to early diagnosis of AS.     

Survey on arteriovenous fistula in maintenance hemodialysis patients with type 2 diabetic nephropathy

This paper summed up the characteristics of native arteriovenous fistulas (AVFs) in maintenance hemodialysis patients with type 2 diabetic nephropathy (DN) in Chinese hemodialysis centers. A survey was conducted on AVF in maintenance hemodialysis patients with type 2 DN. A total of 224 cases of maintenance hemodialysis patients were included in this study, among which, 65 cases in DN group, 33 cases in diabetes mellitus (DM) group and 126 cases in non-diabetic control (C) group. Hemoglobin, albumin, blood urea nitrogen, parathyroid hormone and calcium-phosphate product of the three groups of patients were not significantly different. Glycated hemoglobin A1c of DN group and DM group was not significant different. AVF life of (28.7 ± 10.0) months in DN group was significantly shorter than that of (36.5 ± 19.4) months in C group (statistic probability P <0.01), and AVF life of (32.5 ± 10.1) months in DM group (P <0.05) was also shorter than that in C group, while there was no significant difference in AVF life between DN group and DM group. Proportion of upper arm fistula in DN patients (11/65) was significantly higher than that in C group (6/123, P < 0.01). Life of AVF in patients with DN was relatively short, with more times of angioplasty and greater possibility of selecting upper arm internal fistula.     

Construction of eukaryotic recombinant vector of renalase and its expression as a eukaryotic protein

Renalase is a secreted amine oxidase that metabolizes catecholamines. It has been proposed to modulate blood pressure and heart rate and its downregulation might result in hypertension. Despite its potential relevance for human health, the biochemical characterization of renalase is still scarce. The aim of this study is to synthesize the human renalase eukaryotic protein by genetic engineering. The human renalase gene was amplified by polymerase chian reaction (PCR). After digestion by BamH I and Xho I enzymes, the DNA fragments were cloned into the transfer vector, pFastBacHTb-Fc, to generate the pFastBacHTb-renalase expression vector. The ligation products were transformed into E. coli DH10Bac to obtain recombinant transposon rBacmid-renalase. The recombinant transposon was further transferred into insect high-V cells, and the recombinant human renalase eukaryotic protein was expressed successfully.     

Serum renalase inversely related to heart rate variability in dialysis patients

Heart rate variability （HRV） is a noninvasive technique for autonomic nerve activity assessment and an indirect index of adrenergic cardiovascular drive. Renalase is the only known enzyme degrading circulatory catecholamines, participating in regulations of the cardiovascular and sympathetic nervous systems. This study aims at the relation between serum renalase and HRV indexes in dialysis patients. There were 14 hemodialysis （HD） cases, 16 continuous ambulatory peritoneal dialysis （PD） cases, and 16 healthy volunteers enrolled in this study. All the subjects underwent 24 h Holter testing by using a dynamic electocardiogram monitor system to determine HRV parameters, and serum renalase levels were measured. The standard deviation of normal to normal R-R intervals （SDNN, a measure of beat-to-beat variability）, root mean square successive difference （RMSSD）, and the proportion derived by dividing NN50 （the number of interval differences of successive normal to normal intervals greater than 50 ms） by the total number of NN intervals （pNN50） were determined to assess HRV. Both HD and PD patients presented increased maximum heart rate （Max-HR）, minimum heart rate （Min-HR） and average heart rate （Ave-HR）, and presented decreased SDNN, RMSSD and pNN50 relative to healthy controls. Serum levels of renalase were highly negatively correlated with Ave-HR （correlation coefficient r = -0.68, probability P 〈 0.01）, while positively correlated with SDNN （r = 0.64, P 〈 0.01） in both the HD and PD groups. Serum level of renalase was positively correlated with 24 h urine volume （r = 0.73, P 〈 0.01） in PD patients. Renalase might be reciprocally related to HRV and inversely related to Ave-HR in dialysis patients, which will help to probe into renalase＇s physiology and may pave the way to explore renalase replacement therapy in patients with end stage renal disease （ESRD）.     

Serum levels of RBP4 might not be determined by diabetes mellitus but by kidney function and renal replacement therapy

It has been reported that retinol-binding protein 4(RBP4) is associated to adiposity,insulin resistance,and type 2 diabetes.Meanwhile,circulating RBP4 levels are also affected by renal function.The aim of the present study is to investigate whether serum levels of RBP4 are primarily associated with different stages of chronic kidney disease(CKD) or type 2 diabetes,if there is more potential relevance between RBP4 and renal replacement therapy.The serum levels of RBP4 were assessed by commercial competitive enzyme-linked immunosorbent assay(ELISA)kit in 212 patients with the CKD stages 1—5 and in 24 healthy controls,while its correlation with clinical and metabolic parameters was analyzed.The serum level of RBP4 had a strong correlation with estimated glomerular filtration rate(e GFR)(P 0.001).Stratified by e GFR and treatment,no more differences in RBP4 serum concentration were detected between type 2 diabetic and non-diabetic subjects [CKD stages 1—5,non-dialysis(ND),hemodialysis(HD) and peritoneal dialysis(PD);P 0.05 for all].The elevation of RBP4 become higher in HD than in PD and ND in CKD5 patients(P = 0.008 and P = 0.04,respectively),while there was no significant difference between PD and ND groups.Multivariate linear regression analysis demonstrated three independent predictors of e GFR(β =-0.676,P 0.001),C-reactive protein(CRP)(β =-0.573,P 0.001) and creatine(β = 0.509,P = 0.024) in the study population.The study results demonstrated that the serum level of RBP4 was negatively related to the e GFR,whether diabetes mellitus(DM) affected the blood concentration of RBP4 or not.And the serum level of RBP4 exhibited significant difference in different renal replacement therapies.     

Continuous glucose monitoring in the patients with diabetic nephropathy

The aim of this study was to compare the difference of blood glucose (BG) fluctuation in the patients of type-2 diabetes mellitus (DM-2) with and without clinical diagnosed diabetic nephropathy (DN) by the continuous glucose monitoring system (CGMS). Thirty DM-2 patients with clinical diagnosed DN and fifteen DM-2 patients without complication underwent continuous glucose monitoring for 3 days (72 h) by CGMS. The difference of daily glucose fluctuation in both groups was compared by the parameter of CGMS. The 24-h mean blood glucose (MBG), minimal BG (MIN-BG), area under curve of BG over 7.8 (AUC7.8), percentage of time of BG over 7.8 (PT7.8), area under curve of BG over 11.1 (AUC11.1), percentage of time of BG over 11.1 (PT11.1), as well as mean of daily difference (MODD) were significantly increased in the group of DN, compared with those in the group of DM-2 without complication (all statistic probability P <0.05). No statistical significance of mean amplitude of glycaemic excursion (MAGE) was found. In the group of DN, MBG, standard deviation of blood glucose (SDBG), large amplitude of glycaemic excursion (LAGE), AUC7.8, PT7.8, AUC11.1, PT11.1, MAGE and MODD were (10.7±1.9)mmol/L, (2.5±1.3)mmol/L, (9.2±3.9)mmol/L, 3.2±1.7, (81±18)%, 1.2±1.0, (42±24)%, (5.8±2.5)mmol/L and (2.6±1.5)mmol/L, respectively. The study showed that the BG level of the patients with DN fluctuated throughout the day. MBG of the patients with DN was higher than that of the patients of DM-2 without complications, with the characteristics of long-lasting high BG period, dramatic instability during the day and especially high postprandial blood glucose. CGMS is a useful tool for physicians to know the details of the change of BG in the patients with DN.     

The cloning and expression of renalase and the preparation of its monoclonal antibody

To obtain the recombination protein of renalase and prepare the monoclonal antibody, the human renalase gene was amplified from human kidney by specific primer and cloned the DNA fragments into the pET22b. After verification of the positive clones, the gene was transformed to E. coli BL21 to express the protein with 6His on C terminal. The Balb/c mouse was immunized with the purified protein to prepare the monoclonal antibody by hybidoma technique. The renalase protein was reconstructed and 2 strains of the hybidoma which can stable secrete renalase were obtained. The monoclonal antibody can both react with the both recombinant and human serum renalase. Foundation item: the Scientific Research Project of Shanghai Municipal Health Bureau (2008Y034), and the Natural Scientific Research Project of Shanghai (05ZR14086)