[Effect of Homeobox A13 transfection on epithelial-mesenchymal transition and bone morphogenetic protein-7 expression in kidney tubular epithelial cells].

OBJECTIVE: To examine the transfection of Homeobox A13 (HOXA13) on epithelial-mesenchymal transition (EMT) and the expression of bone morphogenetic protein-7 (BMP-7) induced by albumin-overload in human kidney tubular epithelial cells (HKCs). METHODS: The cultured HKCs were treated with 20 mg/mL human serum albumin (HSA) for 48 hours. Protein expression of cytokeratin (CK), vimentin and HOXA13 in the HKCs was assessed by Western blot. Protein expression of CK, vimentin, and BMP-7 was also detected in HKCs transfected with lipofectamine contained HOXA13 DNA. RESULTS: HSA induced EMT in HKCs, presented by decreased CK expression (P<0.01) and increased vimentin expression (P<0.01). The up-regulated expression of HOXA13 transfected by lipofectamine inhibited the level of EMT induced by HSA in HKCs (P<0.05). The decreased rate of BMP-7 protein expression induced by HSA was inhibited by over-expressed HOXA13 in HKCs (P<0.05). CONCLUSIONS: Transfection of HOXA13 in HKCs could inhibit the degree of EMT induced by albumin-overload, possibly by increasing BMP-7 expression.

[Hazardous environmental factors causing renal damage in children].

Hazardous environmental factors invade the body through multiple routes, including ingestion, inhalation and absorption by contact with the skin and mucous membrane. They are from various sources and soil, water, air, building and decorative materials, foods and daily necessities are the main carriers. According to their physical and chemical properties and morphological characteristics, these hazardous factors are classified as metals, inorganic matter, organic matter, radioactive substances, biological toxins, viruses, bacteria, mycoplasmas, chlamydiae and parasites. They cause diseases through blood and urine and also have kidney susceptibility. This article suggests that pediatricians should fully understand the characteristics and seriousness of hazardous environmental factors that cause renal damage, and pay attention to the prevention and control of these factors so as to minimize renal damage in children.

[Environment and congenital urinary malformations].

The development of the kidneys and other organs of the urinary tract follows the natural rule of gene-environment-lifestyle interaction. Both intrinsic and extrinsic factors may be associated with the etiology of various kinds of urinary malformations, but the environmental factor is an extrinsic factor. Related literatures were reviewed in this paper, which focuses on the association of congenital urinary malformations with possible environmental factors. It is concluded that urinary malformation is associated with low birth weight, maternal disease, placental insufficiency, maternal drug exposure, and maternal exposure to environmental pesticides. Living environment and socioeconomic factors may also influence the incidence of urinary malformation.

Etiology and outcomes of acute kidney injury in Chinese children: a prospective multicentre investigation.

BACKGROUND: The incidence of AKI appears to have increasing trend. Up to now, prospective, multi-center, large-sample epidemiological study done on pediatric AKI on aspects of epidemiological characteristics, causes and outcomes have not reported. It is necessary to develop prospective, multi-center, large-sample epidemiological study in our country on pediatric AKI. The aim of this study was to determine the clinical features, etiology, and outcomes of acute kidney injury (AKI) in Chinese children. METHOD: Paediatric patients (≤18 years old) admitted to 27 hospitals (14 children's hospitals and 13 general hospitals) affiliated with the Medical University were investigated. AKI was defined using the 2005 Acute Kidney Injury Network criteria. RESULTS: During the study period, 388,736 paediatric patients were admitted. From this total, AKI was diagnosed in 1,257 patients, 43 of whom died. The incidence and mortality of AKI was 0.32% and 3.4% respectively. The mean (± SD) age of patients was 48.4 ± 50.4 months. Among the 1,257 AKI paediatric patients, 632 were less than one year old. Among the AKI paediatric patients, 615 (48.9%) were in stage 1, 277 (22.0%) in stage 2, and 365 (29.0%) in stage 3. The most common causes of AKI were renal causes (57.52%), whereas postrenal (25.69%) and prerenal (14.96%) causes were the least common. The three most common causes of AKI according to individual etiological disease were urolithiasis (22.35%), of which exposure to melamine-contaminated milk accounted for the highest incidence (63.7%); acute glomerulonephritis (10.10%); and severe dehydration (7.48%). A total of 43 AKI patients (3.4%) died during their hospital stay; 15 (34.9%) of the 43 died as a result of sepsis. CONCLUSION: Primary renal diseases are a major risk factor for paediatric AKI in China. In terms of specific etiological disease, urolithiasis (postrenal disease) was the leading cause of paediatric AKI in 2008, when the disease was linked to exposure to melamine-contaminated milk. Sepsis is the leading cause of death in Chinese paediatric AKI patients. Future studies should focus on effective ways of controlling renal disorders and sepsis to improve the clinical management of paediatric AKI in China.

Efficacy of antisense monocyte chemoattractant protein-1 (MCP-1) in a rat model of mesangial proliferative glomerulonephritis.

OBJECTIVE: The effects of inhibition of monocyte chemoattractant protein-1 (MCP-1) on a rat model of mesangial proliferative glomerulonephritis (MsPGN) were evaluated. METHODS: The anti-Thy-1 MsPGN model was developed by intravenously injecting anti-Thy-1 monoclonal antibodies into rats, followed by an injection of mesangial cells transfected with antisense MCP-1 into the renal artery. Exogenous cells were detected by in situ hybridization. Rats (40 total) were randomly divided into five groups: SO (sham operation), TG (Thy-1 glomerulonephritis model), MC (non-transfected normal rat mesangial cell), BC (pLXSN empty vector or blank control), and AM (antisense MCP-1 transfection) groups. Effects of exogenous MCP-1 on urinary protein excretion rate, biochemical parameters, and pathological changes were evaluated. Expression of MCP-1 and transforming growth factor-ß1 (TGF-ß1) were detected by immunohistochemistry. mRNA expression of MCP-1, TGF-ß1, and CC chemokine receptor 2 (CCR2) were detected by RT-PCR. RESULTS: Exogenous MCP-1 cDNA was successfully transfected into mesangial cells. Exogenous mesangial cells were detected in glomeruli by in situ hybridization. Glomerular mesangial cell proliferation, 24-h urinary protein excretion rate, mRNA expression of MCP-1, TGF-ß1, and CCR2, and protein expression of MCP-1 all decreased in the AM group as compared to the control group (p < 0.05), but there was no significant difference in the expression level of TGF-ß1 protein. CONCLUSIONS: (1) Mesangial cells can be used as a vector to transfect exogenous genes into kidneys; (2) antisense MCP-1 decreases mesangial cell proliferation and pathological injury in MsPGN model rats by decreasing expression of MCP-1 and CCR2; and (3) antisense MCP-1 suppressed mesangial cell proliferation and matrix accumulation in anti-Thy-1 MsPGN model rats, which did not entirely depend on TGF-ß1.

[Circulating microRNA expression in children with idiopathic short stature].

OBJECTIVE: To study the role of circulating microRNAs (miRNA) in the pathogenesis of idiopathic short stature (ISS) through detecting miRNA expression profile in plasma of children with ISS. METHODS: Plasma miRNA expression was determined by microarray in 20 children with ISS and 20 healthy children. Altered microRNAs were verified by real-time PCR. The online miRNA target gene prediction software was used to predict and screen miRNA differentially expressed target genes. RESULTS: According to the microarray, there were 40 differentially expressed miRNAs in the ISS group compared with the control group, including 24 up-regulated miRNAs and 16 down-regulated miRNAs. Real-time PCR verified two up-regulated (miR-185and miR-574-5p) and two down-regulated miRNAs (miR-497and miR-15a) and confirmed that plasma miR-185 expression was significantly up-regulated (P<0.05) and miR-497 expression was significantly down-regulated (P<0.05) in children with ISS. CONCLUSIONS: Plasma miRNA expression levels in children with ISS are significantly different from healthy controls, suggesting that plasma miRNA is associated with the pathogenesis of ISS.

[Expression of urinary neutrophil gelatinase-associated lipocalin and its clinical significance in children with idiopathic nephrotic syndrome].

OBJECTIVE: To investigate the urinary neutrophil gelatinase-associated lipocalin (NGAL) concentration in children with idiopathic nephrotic syndrome (INS) and its clinical significance. METHODS: Thirty-four children newly diagnosed with INS received oral prednisone for 4 weeks. Patients whose urinary protein did not become negative were classified as steroid-resistant nephrotic syndrome (SRNS) group, while those whose urinary protein did become negative were classified as steroid-sensitive nephrotic syndrome (SSNS) group. Morning midstream urine specimens were collected from all patients before use of prednisone and after 1, 2, 3, and 4 weeks of treatment with prednisone. Enzyme-linked immunosorbent assay was used to measure the urinary NGAL concentration. Meanwhile, urinary creatinine (Cr) concentration was measured, and urinary NGAL concentration in a single urine collection was adjusted according to the urinary Cr excretion. The two groups were compared in terms of urinary NGAL/Cr ratio. RESULTS: Compared with the SRNS group, the SSNS group had significantly decreased urinary NGAL/Cr ratios after 3 and 4 weeks of prednisone treatment (P < 0.05). Compared with the SRNS group, the SSNS group had a significantly decreased urinary ß2-MG/Cr ratio after 4 weeks of prednisone treatment (P < 0.05). In both groups, urinary NGAL/Cr ratio was positively correlated with urinary protein/Cr ratio (r = 0.510, P < 0.01). The results of ROC curve analysis showed when diagnostic cut-off point of urinary NGAL/Cr was 0.043 by 3 weeks after treatment, sensitivity and specificity achieved 100% and 79.2% respectively. CONCLUSIONS: Urinary NGAL/Cr ratio remains high in children with SRNS, while this ratio decreases gradually during prednisone treatment in children with SSNS, and it falls ahead of urinary ß2-MG/Cr ratio. These results suggest that dynamic monitoring of urinary NGAL/Cr ratio is useful for early judgment of response to prednisone in patients with INS.

[Application of stem cell transplantation in kidney diseases].

This paper summarizes the current literature on the potential therapeutic role of stem cell transplantation for kidney injury and repair and focuses on the choice of types of stem cells, the method of transplantation, and the mechanisms of stem cell homing to injured renal tissues and its protective effects. The application of umbilical cord mesenchymal stem cells (UC-MSCs) shows wide prospects, but the approach and optimal dose of cell transplantation are under intensive investigation. Signals that regulate stem cell homing to injured renal tissues may be related to chemokines or factors released in the target site. Several studies have pointed out that paracrine and endocrine of stem cells are the most likely mechanism of action in the injured nephron. Many questions remain unanswered but stem cell-based therapy is a promising new strategy for acute and chronic kidney diseases.

[Relationship between renal Th1/Th2 ratio and renal microvascular injury in children with Henoch-Sch-nlein purpura nephritis].

OBJECTIVE: To explore possible correlations between renal Th1/Th2 ratio and renal microvascular injury in children with Henoch-Sch-nlein purpura nephritis (HSPN). METHODS: Thirty-two children with HSPN were enrolled. They were classified into four groups by renal pathology: HSPN class II (n=8), HSPN class IIIa (n=7), HSPN class IIIb (n=10) and HSPN class IV/V (n=7). Five patients undergoing nephrectomy due to trauma were used as the controls. INFγ, IL-4 and CD34 in the renal tissues were measured by immunohistochemical analysis. INFγ was used as a marker of Th1, IL-4 was used as a marker of Th2 and CD34 was used as a marker of microvessel. The renal microvessel density was evaluated according to the Weidner standard. The relationships among the local Th1/Th2 ratio, renal pathological grade, microvessel score and microvessel density were studied. RESULTS: Immunohistochemical analysis showed a lower expression of INFγ and a higher expression of IL-4 in the HSPN groups than in the control group. The local Th1/Th2 ratio in the HSPN groups decreased and correlated significantly with the renal pathological grade. There were significant differences among four HSPN subgroups (P<0.05). Compared with the control group, the renal microvessel density in the HSPN class II and class IIIa groups increased significantly (P<0.05), but it decreased in the HSPN class IV/V group (P<0.05). The renal microvessel scores in the HSPN class IIIa, class IIIb and class IV/V groups increased significantly compared with those in the control and the HSPN classⅡ. The increased renal microvessel scores were associated with more severe renal pathological changes. A negative correlation was found between the local Th1/Th2 ratio and the microvessel density in kidneys (r=-0.921, P<0.01). CONCLUSIONS: The decrease of Th1/Th2 ratio in kidneys might be responsible for renal microvascular injury in children with HSPN.

[Effects of huai qi huang on cytokines Th1, Th2 and Th17 and phagocytosis of alveolar macrophages in rats with asthma].

OBJECTIVE: To study the effects of huai qi huang, a traditional Chinese medicine, on cytokines Th1, Th2 and Th17 levels and alveolar macrophage phagocytosis in asthmatic rats sensitized by ovalbumin (OVA). METHODS: Forty male Sprague-Dawley rats were randomly divided into five groups: normal control, untreated asthma, budesonide-treated, huai qi huang-treated and budesonide+huai qi huang-treated asthma (n=8 each). Asthma was induced by OVA sensitization and challenge. The levels of IL-4, IFN-γ and IL-17 in plasma and bronchoalveolar lavage fluid (BALF) were measured using ELISA. The phagocytosis of alveolar macrophages which were isolated and purified from BALF was evaluated by the colorimetric assay. RESULTS: The levels of IL-4 and IL-17 increased, in contrast, the IFN-γ level decreased in plasma and BALF in the untreated asthma group compared with those in the normal control group. The IFN-γ level in the huai qi huang-treated asthma group was higher than that in the untreated asthma group. The IFN-γ level increased and the IL-17 level decreased more significantly in the budesonide+huai qi huang-treated asthma group when compared with the budesonide and huai qi huang alone treatment groups. The phagocytosis of alveolar macrophages in the untreated asthma group was lower than that in the normal control group. Huai qi huang alone or combined with budesonide increased the phagocytosis of alveolar macrophages compared with the normal control, untreated asthma and budesonid-treated asthma groups. The levels of IFN-γ in plasma and BALF were positively correlated with the phagocytosis of alveolar macrophages. CONCLUSIONS: The levels of IL-4 and IL-17 increase and the IFN-γ level decreases in plasma and BALF, and the phagocytosis of alveolar macrophages decreases in asthmatic rats. Huai qi huang treatment may increase the IFN-γ expression in plasma and BALF and the phagocytosis of alveolar macrophages in asthmatic rats. There is a synergistic effect between huai qi huang and glucocorticoids.

[Relationship of 24-hour ambulatory blood pressure and rennin-angiotensin-aldosterone system in children with primary nephrotic syndrome].

OBJECTIVE: To investigate the changes of blood pressure by 24-hour ambulatory blood pressure (ABP) monitoring in children with primary nephrotic syndrome (PNS) and explore the relationship of the changes in blood pressure with rennin-angiotensin-aldosterone system (RAAS) in these children. METHODS: ABP and casual blood pressure (CBP) monitoring were performed in 114 children with PNS. Plasma levels of rennin activity (PRA), angiotensin II (AngII) and aldosterone (ALD) were measured. The correlation of plasma levels of PRA, AngII and ALD with ABP was evaluated. RESULTS: Of the 114 children with PNS, 101 (88.6%) presented elevated blood pressure. Mild or severe masked hypertension was found in 45 children (39.5%). Eighty (70.2%) children showed non-dipper blood pressure. The index and load of systolic blood pressure were higher than those of diastolic blood pressure. The blood pressure index and blood pressure load during sleep were higher than those during wakefulness. The boy presented higher diastolic blood pressure index and load than girls. Decubitus blood PRA, AngII and ALD levels in children with PNS were significantly higher than normal controls. The group with elevated blood pressure presented significantly higher decubitus blood PRA, AngII and ALD levels than the group with normal blood pressure. AngII level was significantly positively correlated with the index and load of both systolic blood pressure and diastolic blood pressure. CONCLUSIONS: The children with PNS present a high incidence of hypertension, with a large percentage of masked hypertension and non-dipper blood pressure. Systolic blood pressure increases more significantly than diastolic blood pressure. Blood pressure during sleep increases more significantly than that during wakefulness. Diastolic blood pressure increases more significantly in boys than in girls. RAAS activity is elevated and the elevated RAAS activity might increase the blood pressure mainly by AngII in children with PNS.

Efficacy and safety of tacrolimus and low-dose prednisone in Chinese children with steroid-resistant nephrotic syndrome.

BACKGROUND: Tacrolimus, a calcineurin inhibitor, is recommended by the recent guidelines from the Kidney Disease Improving Global Outcomes Group as the first-line treatment for steroid-resistant nephrotic syndrome (SRNS), but its clinical application in China is still limited. We investigated the efficacy and safety of tacrolimus combined with low-dose corticosteroids in a population of Chinese children with SRNS. METHODS: In this prospective non-randomized, non-controlled study, Chinese children with SRNS who failed the previous full-dose prednisone treatment were given tacrolimus (0.1 mg/kg/day) and low-dose prednisone (0.25-0.50 mg/kg/day). We compared the overall remission rate (ORR) and adverse events in the follow-up period with this therapeutic regimen. RESULTS: A total of 76 children were enrolled into the study with an average follow-up period of 18 ± 6 months (maximum 36 months). ORR achieved by the first, third, and sixth months was 94.7%, 94.7%, and 96.0%, respectively. All patients who attained an initial tacrolimus trough concentration (FK506C0) > 6 ng/mL (60.3%) achieved remission. The relative risk of relapse at FK506C0 < 3 ng/mL compared to 3-6 ng/mL, 6-9 ng/mL, and 9-12 ng/mL was 2.3, 3.2, and 16.9, respectively. During the follow-up period, adverse effects that had been previously reported were rare. CONCLUSIONS: Combination of tacrolimus and low-dose prednisone was safe and effective for the treatment of children with SRNS, with high remission rates observed as early as the first month. Relapses were infrequent, but tended to increase significantly with decreases in FK506C0.

[Protective effect of catechin on renal microvessels in 5/6 nephrectomized rats and its mechanism].

OBJECTIVE: To investigate the effects of catechin on angiotensin-converting enzyme (ACE) activity, angiotensin II(Ang II) content and microvessel density (MVD) in renal tissues of 5/6 nephrectomized rats. METHODS: Sixty SD rats were divided into 3 groups: sham-operated group, untreated group and catechin group. Animal model was reproduced by 5/6 nephrectomy. After 8- and 12-week administration, rats were sacrificed. Renal MVD was measured by immunohistochemical method with CD34 marking. Activities of ACE in plasma and renal cortices were measured by ultraviolet spectrophotometer, and Ang II contents in plasma and renal cortices were measured by radioimmunoassay. Glomerular sclerosis index (GSI) and tubule interstitial score (TIS) were calculated by semiquantitative integration with hematoxylin and eosin staining and periodic acid-Schiff staining. RESULTS: After 8- and 12-week administration, the GSI and TIS in the catechin group were much less than those in the untreated group (P < 0.05, P < 0.01). MVDs around glomerulus and tubule at the end of the 8th and 12th week in the untreated group and the catechin group were much less than those in the sham-operated group (P < 0.01). The ACE activities and Ang II contents in plasma and renal cortices in the catechin group were much less than those in the untreated group (P < 0.01). By Pearson correlation analysis, we found that MVD had negative correlation with GSI, TIS, Ang II content, and ACE activity (P < 0.01), however, the ACE activity and Ang II content had positive correlation with GSI, TIS (P < 0.01). CONCLUSION: Catechin can prevent the 5/6 nephrectomized rats from decreasing of MVD and inhibit the progress of glomerular sclerosis and interstitial fibrosis by inhibiting the activity of ACE and reducing the production of Ang II.

[Preliminary analysis of urinary proteomics in children with steroid-resistant and steroid-sensitive nephrotic syndrome].

OBJECTIVE: To study and identify the protein markers in the urine of children with steroid-sensitive (SSNS) and steroid-resistant nephrotic syndrome(SRNS). METHODS: Total urinary proteins were extracted from children with SSNS before and after steroid therapy, SRNS, and healthy children (n=5 in each group). Urinary proteins were separated by immobilized pH gradient based on two-dimensional gel electrophoresis (2-DE). The silver-stained 2-DE gels were scanned with digital Image Scanner and analyzed with Image Master 2-DE Elite 3.01 software. Peptide mass fingerprint (PMF) of differential protein spots was obtained with MALDI-TOF-MS. Proteins were identified by Mascot software based on NCBI protein database. RESULTS: There were 66 spots with different expression of protein between SRNS children and SSNS children before steroid therapy, and 24 spots and 27 spots only occurred in SRNS children and SSNS children before steroid therapy, respectively. There were 75 spots with different expression of protein between SSNS children after steroid therapy and healthy controls, and 11 spots only occurred in SSNS children after steroid therapy. Eighteen protein spots with different expression (6 spots in each nephrotic group) were chose and analyzed by MALDI-TOF-MS, and 9 types of proteins were identified. CONCLUSIONS: Nine types of urinary proteins with different expression (6 spots in each nephrotic group) were identified between SRNS and SSNS children, and they might be the biomarkers for SRNS or SSNS.

[Effects of clearance of superoxide anion by catechin on the expression of NO and eNOS and apoptosis in endothelial progenitor cells induced by angiotensin II].

OBJECTIVE: To evaluate the effect of clearance of superoxide anion by catechin on the expression of nitrogen monoxidum (NO) and endothelial nitricoxide synthase (eNOS) and apoptosis in endothelial progenitor cells (EPCs) induced by angiotensin II (Ang II). METHODS: The marrow endothelial progenitor cells of Sprague-Dawley rats were isolated and assigned to control (no treatment), Ang II treatment and Ang II + catechin treatment groups. After 48 hrs of culture, the concentration of O2*- in the supernate was measured by the NBT method, and NO concentration in the supernate was measured by the nitrate reductase method; the apoptosis rate of EPCs was detected by the TUNEL method; the mRNA expression of eNOS was detected by RT-PCR; the protein expression of eNOS was detected by Western blot analysis. RESULTS: Ang II of 10-6 mol/L was determined as the suitable concentration for cell induction by the MTT test. Catechin of 400 mg/L was determined as an advisable intervention dosage. The apoptosis rate of EPCs in the control, the Ang II and the Ang II+catechin treatment groups were 2.48+/-0.12%, 54.18+/-0.77% and 16.87+/-0.35%, respectively, and there were significant differences among the three groups (P<0.01). The O2*- concentration in the Ang II and the Ang II+catechin treatment groups (81.7+/- 3.6 and 62.3+/- 2.2 U/L respectively) was significantly higher than that in the control group (33.7+/- 2.8 U/L) (P<0.01). An increased NO concentration was also found in the Ang II (189. 8+/- 9.0 micromol/L) and the Ang II+catechin treatment groups (276.4+/- 10.1 micromol/L) compared with that in the control group (105.8+/- 9.8 micromol/L) (P<0.01). There were significant differences in the concentrations of O2*- and NO between the Ang II and the Ang II+catechin treatment groups (P<0.05). The mRNA (P<0.05) and protein expression (P<0.01) of eNOS in the Ang II and the Ang II+catechin treatment groups increased significantly compared with those in the control group. The Ang II+catechin treatment group showed increased eNOS protein expression compared with the Ang II group (P<0.05). CONCLUSIONS: Ang II may induce the generation of O2*-, inactivate NO and increase gene and protein expression of eNOS in EPCs. Catechin might decrease the apoptosis of EPCs through the effective clearance of O2*-and the reduction of NO inactivation and of eNOS protein uncoupling.

[Relationship between impulsivity and sleep disorders in children aged 6 to 12 years].

OBJECTIVE: To study the relationship between impulsivity and sleep disorders in children. METHODS: A total of 1 736 children at ages of 6 to 12 years were randomly sampled from five districts of Changsha. Their parents completed the questionnaires about children's sleep conditions and behaviors (using Barratt Impulsiveness Scale 11th version). RESULTS: Five hundred and fifty-four children (31.9%) had sleep disorders. The incidence of sleep disorders in boys was significantly higher than that in girls (35.4% vs 28.3%; P<0.01). The scores of attentional, motor, and non-planning impulsiveness factors as well as the total score of Barratt Impulsiveness Scale in children with sleep disorders were significantly higher than those in children without (P<0.01). The incidence of daytime sleepiness (35.9%) in children with sleep disorders was significantly higher than that in children without (24.7%; P<0.01). The scores of attentional, motor, and non-planning impulsiveness factors increased with the grade of sleep disorders, and reached a peak at the fifth grade. The children with frequent sleep snoring showed higher scores of above three impulsiveness factors than children without sleep snoring or having rare snoring (P<0.01). CONCLUSIONS: Sleep disorders are associated with impulsivity in children. It is thus essential to pay close attentions to children's sleep for children with relatively high impulsiveness.

[Expression of vascular endothelial growth factor is related to microvessel injury of renal interstitium in children with Henoch Schönlein purpura nephritis].

OBJECTIVE: To investigate the relationship between vascular endothelial growth factor (VEGF) expression and microvessel injury of renal interstitium in children with Henoch-Schönlein purpura nephritis (HSPN). METHODS: Thirty-two children with HSPN and who had not received glucocorticoid or immunodepressants treatment before hospitalization were enrolled. Five children undergoing nephrectomy due to renal trauma were used as the control group. Renal samples were stained by hematoxylin and eosin and renal pathological changes were evaluated semi-quantitatively. CD34 and VEGF expression was detected by immunohistochemistry. CD34 was used as the marker for endothelial cells of renal microvessels. The microvessel density (MVD) was calculated by CD34 immunostaining. RESULTS: Compared with the control and the renal pathological grade II HSPN groups, MVD in the grade III and above HSPN groups decreased significantly, with an obvious reduction in MVD with the increased renal pathological grade (p<0.05). The renal microvessel score in the grades IIIa, IIIb, IV, and V HSPN groups decreased obviously compared with that in the control group. The renal microvessel score decreased with the increased renal pathological grade (p<0.05). VEGF expression in the grade II HSPN group was higher (p<0.05), while that in the grades IV and V HSPN group was lower than that in the control group (p<0.05). VEGF expression in the HSPN group showed a significant reduction with the increased renal pathological grade (p<0.05). There was a positive correlation between VEGF expression and MVD in renal tissue in the HSPN group (r=0.935, p<0.01). CONCLUSIONS: The decreased expression of VEGF may be responsible for the renal pathological damage and microvessel injury in HSPN.

[Protective effects of catechin on apoptosis of endothelial progenitor cells induced by H2O2 in rats].

OBJECTIVE: To study the effect of H2O2 on the proliferation and apoptosis of endothelial progenitor cells (EPCs) and the antogonistic effects of catechin on the cell apoptosis induced by H2O2 in rats. METHODS: Immuno-fluoreascence assay was applied to detect CD34, CD133 and VEGFR-2 expression. EPCs of generation 2 were divided into control cells, H2O2-treated cells and catechin-H2O2-treated cells (H2O2: 100 mg/L; catechin: 10 mg/L). Genomic DNA was extracted by the conventional method after intervention for the analysis of apoptosis ladder pattern. The MTT assay was applied to detect proliferation rate of EPCs. RESULTS: The cultured cells at day 10 expressed CD34, CD133 and VEGFR-2. DNA apoptosis ladder pattern appeared in H2O2-treated cells 2 days after intervention. After 3 days of intervention DNA apoptosis ladder pattern appeared in both H2O2-treated cells and H2O2-catechinjtreated cells, with more ladders and grayer scale in H2O2 -treated cells. Compared with the controls, H2O2-treated cells and H2O2-catechin-treated cells showed significantly decreased proliferation rate (p<0.01), with the lowest proliferation rate at the 2nd day (p<0.05). The H2O2-catechin-treated cells showed increased proliferation rate than H2O2-treated cells at the 1st, 2nd and 3rd days. CONCLUSIONS: H2O2 may impair EPCs proliferation and induce EPCs apoptosis. Catechin may increase the capacity of EPCs for the resistance to apoptosis induced by H2O2.

Usefulness of mizoribine administration in children with frequently relapsing nephrotic syndrome, and the relationship between pharmacokinetic parameters and efficacy: a multicenter prospective cohort study in China.

BACKGROUND: Mizoribine (MZR) is an immunosuppressant used to treat adult nephropathy. There is little experience with the drug in treating Chinese children with frequently relapsing nephrotic syndrome (FRNS). We investigated the efficacy and safety for treating MZR with FRNS. Furthermore, the relationship between efficacy and serum concentration was investigated. METHODS: A prospective multicenter observational 12-month study was performed for evaluating the usefulness of MZR with FRNS. Serum MZR concentration was measured, and the relationships between pharmacokinetic parameters (Cmax, AUC), number of relapses, and urinary protein were evaluated. RESULTS: Eighty-two pediatric patients from four hospitals were treated with MZR and prednisone. MZR treatment significantly reduced the number of relapses and steroid doses. A correlation between pharmacokinetic parameters and relapses was observed, which fits well with the sigmoidal Emax model. Even in the relationship between pharmacokinetic parameters and urinary proteins, it was recognized that there was a threshold in the pharmacokinetic parameters for the therapeutic effect similar to the results obtained with the sigmoidal Emax model. Eleven patients (13.4%) experienced mild adverse events. CONCLUSIONS: MZR therapy was effective in reducing the number of relapses and steroid doses. No severe adverse reactions were observed. Therapeutically effective serum concentrations were estimated to be Cmax ≥ about 2 µg/mL or AUC ≥ about 10 µg h/mL. MZR and steroid treatment were effective and safe for pediatric FRNS.