Deceleration Performance and Parameter Influence Analysis of the Control Rod Hydraulic Deceleration Device for Control Rod Hydraulic Drive System

Control rod hydraulic drive system (CRHDS), which is invented by INET, Tsinghua University, is a new type of internal control rod drive technology. Control rod hydraulic deceleration device (CRHDD), which consists of the plug, the hydraulic deceleration cylinder, etc., is one of the main components of the CRHDS. The CRHDD performs the rod dropping deceleration function through the interworking of the plug and the deceleration cylinder, which is filled with water, and reduces the rod dropping peak acceleration and the impact force acting upon the control rod to prevent the control rod cruciform blade from being deformed or damaged. The working mechanism of the CRHDD is presented and analyzed. The theoretical model of the control rod dropping process, which is based upon force analysis of the control rod during scram process, three-dimensional flow field analysis, and flow resistance calculation of the hydraulic deceleration cylinder, the kinematics and dynamics analysis of the control rod, is built whose results are compared and validated by the CRHDS scram test results. Then the model is used to analyze the influence of the key parameters, including the fuel case gap, the plug design clearance, the working temperature, etc. on the CRHDD working performance. The research results can give guidance for the design and optimization of the CRHDD.

Clinical-pathological features and prognosis of thrombotic thrombocytopenic purpura in patients with lupus nephritis

BACKGROUND

We investigated the clinical-pathological features and the prognosis of thrombotic thrombocytopenic purpura (TTP) in patients with lupus nephritis (LN).

METHODS

A retrospective analysis was performed on the clinical-pathological data and prognosis in 8 patients with LN complicating with TTP.

RESULTS

Thrombocytopenia and hemolytic anemia, neurologic symptoms, and renal dysfunction were the clinical manifestations in 8 patients. Six patients had fever. Eight patients presented with rapid progressive glomerulonephritis, and 1 patient with continuous gross hematuria. The histologic features of the 8 patients were thrombotic microangiopathy lesions. Immune-suppressive therapies were administrated in all patients, and blood purification therapy was applied in 7 patients. Three cases involved plasma exchange and/or immunoabsorption. Seven patients received a median follow-up of 12 months. One patient died, 3 cases received peritoneal dialysis, and 1 case failed to follow-up. During follow-up, 1 case was able to stop peritoneal dialysis, and 1 case changed to hemodialysis. The other 3 patients continued with stable renal function.

CONCLUSION

The patients with LN with TTP have severe clinical-pathological changes. Active treatment including renal replacement therapy, plasma exchange, and immunoabsorption are promising.

Successful treatment of patients with lipoprotein glomerulopathy by protein A immunoadsorption: a pilot study

BACKGROUND

No established therapy is available for patients with lipoprotein glomerulopathy (LPG). Protein A immunoadsorption has been proved to be effective in reducing proteinuria in patients with nephrotic syndrome. In this uncontrolled pilot study, we investigated the efficiency of immunoadsorption onto staphylococcal protein A as treatment for LPG.

METHODS

Thirteen patients with renal biopsy-proven LPG were treated with staphylococcal protein A immunoadsorption. Immunoadsorption was administered for 10 cycles per session and 10 sessions as a course. A total of 30 l of plasma was regenerated in each course.

RESULTS

Single immunoadsorption course led to a rapid decline in proteinuria from 4.01 +/- 3.09 g/24 h to 1.21 +/- 0.97 g/24 h (mean +/- SD) (n = 13, P = 0.001), along with a dramatic decline in apolipoprotein E (apo E) from 9.79 +/- 5.04 mg/dl to 6.20 +/- 2.22 mg/dl (P = 0.004). A repeated renal biopsy (n = 12) showed that intraglomerular lipoprotein thrombi almost disappeared. Six patients were enrolled in the investigation of long-term outcome, and proteinuria returned to baseline levels within 12 months. Four recurrent patients received repeat immunoadsorption treatment; proteinuria decreased from 5.02 +/- 1.85 g/24 h to 1.64 +/- 0.55 g/24 h at the end of the treatment, serum apo E decreased from 14.65 +/- 11.17 mg/dl to 7.90 +/- 1.72 mg/dl. No patients suffered from severe complications.

CONCLUSION

Our observations suggest that immunoadsorption onto protein A might be an effective treatment for resolving intraglomerular thrombi and improving nephrotic syndrome in patients with LPG. Further studies are required to define the influence of immunoadsorption on long-term effects in LPG patients.

Spectrum of clinical features and type IV collagen alpha-chain distribution in Chinese patients with Alport syndrome

BACKGROUND

Alport syndrome (AS) is a clinically and genetically heterogeneous nephropathy. The goal of the present study is to delineate clinical characteristics and the distribution of type IV collagen chains in Chinese AS patients and to identify any alpha(IV)-chain expression and clinical phenotype correlation.

METHODS

A total of 126 biopsy-proven patients meeting immunofluorescence criteria for the diagnosis of AS were investigated retrospectively.

RESULTS

Microscope haematuria associated with proteinuria was observed as the initial symptom in 77.8% of the patients; 59.8% showed hearing impairment and 22.9% had ocular abnormalities. Renal biopsies from 118 patients revealed mesangial proliferative glomerulonephritis (61.9%) and focal and segmental sclerosis glomerulonephritis (37.3%). Ten different distribution patterns for the type IV collagen alpha-chains were found in the kidney; six of these are presented here for the first time. Based on renal immunofluorescence findings, 113 patients (89.7%) were classified as X-linked dominant inherited AS (XLAS) and 13 (10.3%) as autosomal recessive AS (ARAS). The XLAS group was divided into typical and non-typical subgroups according to the expression patterns for the alpha3(IV)-chain. Clinical phenotypes were more severe in XLAS patients than in ARAS patients and the prognosis was poorer in typical XLAS patients than non-typical XLAS patients.

CONCLUSION

In China, the incidence of XLAS is 89.7% and 10.3% for ARAS. Chinese patients with AS have various distribution patterns of type IV collagen alpha-chains. The distribution pattern of type IV collagen alpha-chains in the kidney may correspond to the severity of the clinical phenotype.

Sequential Hemoperfusion and Continuous Venovenous Hemofiltration in Treatment of Severe Tetramine Poisoning

<i>Objective:</i> It was the aim of this study to observe the effects of sequential hemoperfusion (HP) and continuous venovenous hemofiltration (CVVH) on patients with severe tetramine poisoning and to evaluate the ability of these modalities to remove tetramine. <i>Methods:</i> Eighteen patients diagnosed as having severe tetramine poisoning were treated by blood purification, additional to routine medical therapy. Blood purification procedures included HP using activated charcoal for 3–5 h and consecutive CVVH for 24–36 h. Patients’ clinical conditions, blood routine tests and serum chemical tests were evaluated every day after admission. Plasma tetramine concentrations were determined before and after HP. During CVVH, tetramine concentrations in plasma before and after passing through the filter and ultrafiltration at 2 and 12 h were also determined. <i>Results:</i> Eight patients received blood purification within 12 h after onset of poisoning, and 10 patients received blood purification more than 12 h later. Early-treated patients showed a higher cure rate (100 vs. 60.0%; p < 0.05, χ² test) and shorter coma time than late-treated patients (26.0 ± 23.2 h, range 5–70, vs. 59.7 ± 27.7 h, range 20–96; p < 0.01, rank test). The mean plasma tetramine concentrations in early- and late-treated patients were comparable (0.095 ± 0.036 vs. 0.134 ± 0.110 mg/l; p > 0.05). Mean plasma tetramine concentration was reduced from 0.124 ± 0.082 to 0.080 ± 0.055 mg/l after HP. At 2 h of CVVH, mean plasma tetramine concentration was 0.078 ± 0.064 mg/l, at 12 h of CVVH, 0.074 ± 0.059 mg/l, and the ultrafiltration sieving coefficient at 2 and 12 h was 0.839 ± 0.409 and 0.686 ± 0.253 mg/l, respectively. <i>Conclusion:</i> Early sequential HP and CVVH therapy may significantly improve the outcome of patients with severe tetramine intoxication. HP can rapidly reduce the plasma concentration of tetramine, and CVVH can attenuate the plasma tetramine concentration rebound after HP by continuously removing tetramine from the plasma.

Novel rescue therapy for C4d-positive acute humoral renal allograft rejection

OBJECTIVE

To investigate the efficacy of immunoadsorption (IA) in combination with tacrolimus (TAC) and mycophenolate mofetil (MMF) rescue therapy for C4d-positive acute humoral rejection (AHR) of renal transplants.

METHODOLOGY

Six of 185 cadaveric renal allograft recipients transplanted at our institute developed AHR over a mean period of 4.8 +/- 0.8 d after operation. The ages ranged from 35 to 51 yr (mean 42.6 +/- 5.6 yr). C4d deposits in peritubular capillaries (PTC) and accumulation of granulocytes in PTC were observed. IA with staphylococcal protein A and TAC-MMF combination therapy were given.

RESULTS

After subjected to IA for 6.3 +/- 1.03 sessions combined with TAC (0.14-0.16 mg/kg/d) and MMF (1.5 g/d) therapy, renal function recovered in all the patients. The mean duration of treatment when serum creatinine decreased was 14 +/- 2.9 d. The pre-IA panel reactive antibody reactivity was as high as 50.2 +/- 6.1%, and was significantly reduced to 8.3 +/- 2.9% after IA. Repeated allograft kidney biopsy in four of six patients revealed a favorable remission of AHR. With a mean follow-up of 18.8 +/- 5.46 months, patient and allograft survival are 100%, renal function remained stable with a mean serum creatinine of 1.2 +/- 0.22 mg/dL.

CONCLUSION

The optimal treatment for alloantibody-mediated AHR remains undefined. Our findings suggest that a therapeutic approach combining IA and TAC-MMF rescue has excellence to improve the outcome of AHR.

Effects of methylprednisolone and cyclophosphamide pulse therapy on renal infiltrating cells in patients with crescentic glomerulonephritis

OBJECTIVE

To investigate the effects of pulse methylprednisolone (MP) and monthly intravenous cyclophosphamide (CTX) therapy (MP + CTX) on renal infiltrating cells in patients with rapid progressive glomerular nephritis (RPGN).

METHODS

Twelve patients with RPGN (> 50% crescents) were given MP + CTX therapy and received repeated renal biopsies within 4 to 12 weeks after MP + CTX treatment. Seven were diagnosed as type II RPGN, including one case of IgA nephropathy, 2 cases of idiopathic RPGN and 4 cases of lupus nephritis and five were diagnosed as type III RPGN, including 2 cases of idiopathic RPGN and 3 cases of vasculitis. The changes of infiltrating CD4+, CD8+, CD68+ and proliferating cell nuclear antigen-PCNA+ cell levels were determined by four PAP method in glomeruli and interstitium.

RESULTS

In the patients before MP + CTX therapy, there were higher levels of infiltrating CD4+ and CD8+ cells (306 +/- 118 and 223 +/- 98.4Num/mm2) in renal interstitium, CD68+ cells (17.2 +/- 9.95 Num/G) in glomeruli and (1120 +/- 229 Num/mm2) in interstitium, and PCNA+ cells (7.56 +/- 3.57 Num/G) in glomeruli and (17.6 +/- 6.85 Num/mm2) in interstitium as compared with those in the patients after MP + CTX therapy (CD4+/CD8+ cells were 171 +/- 87.5/121 +/- 38.4 Num/mm2, CD68+ cells were 9.04 +/- 4.33 Num/G and 600 +/- 107 Num/mm2, and PCNA+ cells were 2.04 +/- 1.43 Num/G and 9.40 +/- 4.45 Num/mm2). These changes were associated with improving renal dysfunctions (the levels of serum creatinine and proteinuria decreased gradually from 766 +/- 356 to 284 +/- 192 mumol/L and 2.60 +/- 1.46 to 1.29 +/- 0.85 g/day).

CONCLUSIONS

Our data indicate that the renal infiltrating cells may play an important role in renal injury in patients with RPGN. The effects of MP + CTX therapy on improving renal dysfunctions may partially contribute to its amelioration of infiltrating cells in renal tissues. The degrees of CD4+, CD68+, and PCNA+ cells in the kidney may be useful indicators of MP + CTX therapy for RPGN.