| Part I Establishment and identification of rat IgA nephropathy model and the effect of methylprednisolone on the modelObjective To investigate the feasibility and stabilization of establishing rat IgA nephropathy by oral immunity method,and to explore the effect of methylprednisolone pretreatment on the model.Methods Forty Sprague Dawley rats were randomly divided into control group(8),model group(8),low-dose methylprednisolone pretreatment(8),mid-dose methylprednisolone pretreatment(8),and high-dose methylprednisolone pretreatment(8).Model group was administered oral bovine serum protein,subcutaneous injection of carbon tetrachloride and intravenous of lipopolysaccharide subsequently to induce IgA nephropathy,control group was administered every step as well as model group instead of equal 0.9%sodium chloride,and the rest 3 groups were additionally administered low-dose(5mg/kg),mid-dose(1 Omg/kg),and high-dose(20mg/kg)methlprednisolone respectively after the same procedure of model group.Survival status and weight variation of the rats were observed.Urine samples of the rats were collected with metabolic cage and analyzed to determine the urinary erythrocytes count in precipitation and 24-hour quantization of urinary protein at week 0,6,12.All the rats were sacrificed at week 12 and blood samples as well as kidney tissues were obtained to carry out biochemistry test and immunopathology examination,respectively.Results the number of survival rats were 8,6,5,7,3 in control group,model group,low-dose methylprednisolone pretreatment,mid-dose methylprednisolone pretreatment,and high-dose methylprednisolone pretreatment,respectively.There is a significant difference of survival rate between control group and high-dose methylprednisolone pretreatment(P<0.05).No significant difference of weight between every two groups was found during the first 6 weeks(P all>0.05).Then,the weight of model group and high-dose methylprednisolone pretreatment decreased significantly after week 6(P all<0.01).The urinary erythrocytes count in model group and low-dose methylprednisolone pretreatment significantly increased after week 6(P<0.01 and P<0.05,respectively).The urinary erythrocytes count in all groups significantly increased at week 12 except control group(P<0.01,P<0.05,P<0.05 and P<0.01,respectively).The quantization of 24-hour urinary protein in all groups significantly increased at week 12 except control group and mid-dose methylprednisolone pretreatment(P all<0.05).The serum albumin of model group,low-dose methylprednisolone pretreatment and high-dose methylprednisolone pretreatment were significant lower than that of control group(P all<0.01).However,no significant difference of serum albumin was found between mid-dose methylprednisolone pretreatment and control group(P>0.05).The serum total protein of model group and low-dose methylprednisolone pretreatment were significant lower than that of control group and mid-dose methylprednisolone pretreatment(P<0.05).The serum cystatin C of model group and low-dose methylprednisolone pretreatment were significant lower than that of control group and mid-dose methylprednisolone pretreatment(P<0.01).No significant difference of serum creatinine and urea nitrogen was found between every two groups(P all>0.05).The Hematoxylin-Eosin stain and Periodic acid-Schiff stain of kidney tissue in model group present an increase in mesangial matrix and hypercellularity and the immunohistochemistry stain with IgA appear the predominance of IgA deposits in mesangial matrix.Though the pathology of the three methylprednisolone pretreatment improved,appearance of increase in mesangial matrix and hypercellularity still could be found to some extent.The IgA positive rate of glomenruli in model group,low-dose methylprednisolone pretreatment and high-dose methylprednisolone pretreatment were significantly higher when compared with control group(P all<0.01).Nevertheless,no significant difference of IgA positive rate of glomenruli was found between mid-dose methylprednisolone pretreatment and control group(P>0.05).Conclusions It's a reliable and stable method to induce rat IgA nephropathy model by taking bovine serum protein orally.Methylprednisolone preconditioning with IgA nephropathy rat model can ameliorate the developing of hematuresis and proteinuria,thus protecting kidney and getting good outcome,especially in mid-dose methylpradnisolone pretreatment.Part II The role of a proliferation-inducing ligand and follicular dendritic cell secreted protein in IgA nephropathy and the effect of methylprednisolone on these two factorsObjective To investigate the role of follicular dendritic cell on IgA nephropathy by detecting the expression of a proliferation-inducing ligand and follicular dendritic cell secreted protein at the transcriptional level and translating level in Peyer's patches.Furthermore,to study the effect of methylprednisolone on these two factors so that to clarify the potential mechanism of methylprednisolone in the treatment of IgA treatment.Methods Forty Sprague Dawley rats were randomly divided into control group(8),model group(8),low-dose methylprednisolone pretreatment(8),mid-dose methylprednisolone pretreatment(8),and high-dose methylprednisolone pretreatment(8).Model group was administered oral bovine serum protein,subcutaneous injection of carbon tetrachloride and intravenous of lipopolysaccharide subsequently to induce IgA nephropathy,control group was administered every step as well as model group instead of equal 0.9%sodium chloride,and the rest 3 groups were additionally administered low-dose(5mg/kg),mid-dose(10mg/kg),and high-dose(20mg/kg)methlprednisolone respectively after the same procedure of model group.At week 12,serum IgA and monocyte chemoattractant protein-1 were detected by using enzyme-linked immunosobent assay.Immunohistochemistry method was used to realize the expression of a proliferation-inducing ligand in Peyer's patches.Western blot was carried out to determine the expression of a proliferation-inducing ligand and follicular dendritic cell secreted protein in Peyer's patches and the expression of monocyte chemoattractant protein-1 in kidney tissue at translational level.Real-time PCR was used to measure the expression of a proliferation-inducing ligand and follicular dendritic cell secreted protein in Peyer's patches and the expression of monocyte chemoattractant protein-1 in kidney tissue at transcriptional level.Results The positive expression rate of a proliferation-inducing ligand in Peyer's patches were 38.64±7.52(%)?32.56±6.82(%)?10.29±3.21(%)with model group,low-dose methylprednisolone pretreatment and high-dose methylprednisolone pretreatment,respectively vs.5.20±0.85(%)?8.76±2.07(%)with control group and mid-dose methylprednisolone pretreatment(P<0.01).The serum IgA and monocyte chemoattractant protein-1 were significant higher in model group and low-dose methylprednisolone pretreatment than in the rest 3 groups(P all<0.01).The expression of follicular dendritic cell secreted protein in model group was significantly lower than that in control group(P<0.01).On the contrary,the expression of a proliferation-inducing ligand was significantly higher in model group than that in control group(P<0.01).The level of follicular dendritic cell secreted protein in Peyer's patches was descend with dose increasing of methylprednisolone,while the level of a proliferation-inducing ligand varied inversely(P all<0.01).The mRNA expression of a proliferation-inducing ligand in Peyer's patches was coincide with protein expression of the factor.However,the mRNA expression of follicular dendritic cell secreted protein was scarce.The expression of monocyte chemoattractant protein-1 in kidney tissue of model group significantly increased than that of control group(P<0.01),then decreased with dose increasing of methylprednisolone(P<0.01).The mRNA expression of monocyte chemoattractant protein-1 in kidney tissue was line with its variation trend at translational level.Conclusions Follicular dendritic cell may modulate IgA class switch by secreting a proliferation-inducing ligand in Peyer's patches,which maybe a potential mechanism involved in the occurrence and developing of IgA nephropathy.Follicular dendritic cell secreted protein in Peyer's patches may also affect the occurrence and developing of IgA nephropathy through inhibiting IgA class switch,whereas follicular dendritic cell is not predominant source of the factor in Peyer's patches.Methylprednisolone may perform protective effect by modulating transcription and translation of a proliferation-inducing ligand and recruiting follicular dendritic cell secreted protein in Peyer's patches.Furthermore,mega-dose methylprednisolone can inhibit the expression of monocyte chemoattractant protein-1 in kidney tissue and influence the clearance of immune complex in kidney,resulting in hard recovery of IgA nephropathy.Part ? Risk factors and prognostic factors of acute kidney injury in children:a retrospective study between 2003 and 2013Objectives:Recent report on epidemiology of acute kidney injury(AKI)is lacking for Chinese children.We aimed to investigate the risk factors for stage and prognostic factors for renal recovery in hospitalized children.Materials and Methods:Pediatric patients(? 18 years old)admitted during 2003 to 2013 were enrolled in this study.AKI was defined and staged using Kidney Disease Improving Global Outcomes(KDIGO)criteria.Logistic regression analysis was performed to determine the risk factors and prognostic factors.Results:The morbidity of pediatric AKI was 0.31%(205/65237).There were 45(22.0%)cases in stage ?,30(14.6%)cases in stage ? and 130(63.4%)cases in stage ?.The majority of etiologies were intrinsic renal defects(85.4%).Of the various urological disorders,acute post-streptococcal glomerulonephritis(APSGN),primary nephrotic syndrome(PNS),acute interstitial nephritis(AIN)and lithangiuria were the leading four causes.Age,weight,vomit,etiology,blood urea nitrogen(BUN)at admission and several blood gas measurements were associated with AKI stage ?.Age(OR=0.894;95%CI,0.832-0.962;P=0.003),vomit(OR=2.375;95%CI,1.058-5.333;P=0.036)and BUN at admission(OR=1.135;95%CI,1.085-1.187;P<0.001)were identified as independent risk factors for AKI stage ?.After treatment,172(83.9%)patients achieved complete or partial recovery.The mortality was 3.9%.Variables were found as prognostic factors for renal recovery,such as age,stage,hospital stay,BUN at discharge,white blood cell(WBC),red blood cell(RBC),platelet(PLT),blood PH and urine blood(BLD).Among them,AKI stage(stage ? vs.stage I;OR,6.506;95%CI,1.640-25.816;P=0.008),BUN discharge(OR,0.918;95%CI,0.856-0.984;P=0.016)and PLT(OR,1.007;95%CI,1.001-1.013;P=0.027)were identified as independent prognostic factors.Conclusion:AKI is still common in Chinese hospitalized children.The morbidity was 0.31%,and the renal recovery rate and mortality rate was 83.9%and 3.9%,respectively.Attention should be given to infant patients with urological diseases.Additionally,AKI stage and the levels of BUN and PLT should be monitored during treatment. |
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