Kazuro Yagi

Mycophenolate mofetil therapy for children with intractable nephrotic syndrome.

Background: Cyclosporin A (CyA) can suppress relapses and reduce proteinuria in frequent‐relapse nephrotic syndrome (FRNS) and steroid‐resistant nephrotic syndrome (SRNS). However, some patients remain resistant to CyA therapy. The purpose of the present paper was to evaluate mycophenolate mofetil (MMF) treatment in pediatric patients with CyA‐resistant intractable nephrotic syndrome.

Clinical features and treatment of children with hemolytic uremic syndrome caused by enterohemorrhagic Escherichia coli O157:H7 infection: experience of an outbreak in Sakai City, 1996.

Abstract Presented is a study of 15 patients (seven males and eight females ranging between 5 and 10 years of age) with hemolytic uremic syndrome (HUS) associated with hemorrhagic colitis that was caused by enterohemorrhagic Escherichia coli (EHEC) O157:H7, encountered during the outbreak in Sakai City in July, 1996. The complete form of HUS, which includes the three characteristics hemolytic anemia, thrombocytopenia and acute renal dysfunction, was noted in eight patients, while an incomplete form of HUS, which did not include all three characteristics, was noted in seven patients. Regarding treatment, intravenous γ‐globulin was administered in nine patients and dialysis was performed in five patients (two males and three females) with the complete form of HUS. In three of these five patients, plasma exchange was also performed. Weaning from dialysis was accomplished by the 15th day of disease in all patients. Some patients developed pancreatitis, central nervous system symptoms, fundal hemorrhage and elevation of transaminase, although these abnormalities subsided uneventfully. Renal biopsy, which was performed in two patients who recovered from acute renal failure but still had mild proteinuria and a decrease in creatinine clearance, showed moderate changes in the glomeruli and tubulointerstitium. One year after onset of disease, hematological and urological findings were within normal limits in all patients except one with the complete form of HUS, who still had slightly decreased creatinine clearance.

Proto-oncogene expression in human glomerular diseases

The expression of the protein products and mRNA of c‐fos, c‐myc, p53, and c‐raf was examined in normal renal tissues and biopsy specimens from 73 patients with various glomerular diseases. Immunofluorescent staining showed that there were cell nuclei stained for c‐Fos, c‐Myc, and p53, and cytoplasm positive for c‐Raf, in the glomeruli of patients with proliferative types of glomerulonephritis, including IgA nephritis and lupus nephritis, and in patients with focal glomerular sclerosis. Glomerular expression of c‐fos and c‐myc mRNA was detected by in situ hybridization. The number of proto‐oncogene‐positive glomerular cells was significantly higher in lupus nephritis, IgA nephritis, and focal segmental sclerosis, as compared with minimal change nephrotic syndrome and normal specimens. In IgA nephritis, the population of glomerular cells positive for c‐Fos and c‐Myc and the grade of c‐Raf immunoreactivity were significantly correlated with the proportion of proliferating cell nuclear antigen (PCNA)‐positive glomerular cells, with histological grading of mesangial hypercellularity and matrix increase, and with the magnitude of proteinuria. These data indicate that proto‐oncogene expression is associated with mesangial proliferation and matrix expansion in proliferative types of glomerulonephritis and in focal glomerular sclerosis.

Glucocorticoid-Induced Apoptosis of Rat Mesangial Cells in Culture

BackgroundApoptosis of glomerular mesangial cells is shown in experimental and human glumerulonephritis. But it is unclear whether or not glucocorticoids can induce apoptosis in mesangial cells.MethodsRat mesangial cells in culture were incubated with dexamethazone and methylprednisolone. Apoptosis was evaluated by DNA-specific staining with fluorescent dye (H33258), in situ nick end labeling, gel electrophoresis of extracted DNA, and electron microscopy.ResultsThe proportion of lysed cells and cells positive for nick end labeling increased at a concentration of 0.2 to 5 mmol/L of dexamethazone and methylprednisolone. Chromatin condensation and DNA ladders in those cells were also seen. Actinomycin D, a transcriptional inhibitor, or cycloheximide, a translational inhibitor, partially blocked glucocorticoid-induced apoptosis of rat mesangial cells.ConclusionsGlucocorticoids induced typical apoptosis in rat mesangial cells. These data provide new information on the pharmacologic action of glucocorticoids on mesangial cells.

A boy undergoing maintenance hemodialysis who developed mediastinal lymph node tuberculosis.

The incidence of tuberculosis (TBC) in patients undergoing maintenance hemodialysis is reported to be higher than that in the general population. We report an 8-year-old boy receiving such treatment for chronic renal failure who developed mediastinal lymph node TBC. He showed only intermittent fever, recurring every 2 weeks, with no other symptoms suggesting TBC. Although staining and culture of pharyngeal swab and gastric juice specimens failed to provide evidence of TBC, a lymph node biopsy specimen disclosed typical pathologic findings of tuberculoma, including caseating granulomas. Antituberculous therapy with isoniazid (INH), rifampicin, pyrazinamide, and ethambutol was given for 12 months, resulting in complete resolution of the TBC, with no subsequent recurrence. To our knowledge, mediastinal lymph node localization of TBC is relatively rare, in a patient on maintenance hemodialysis, especially in a child.

Comparison of antiproteinuric effects of two different combination therapies in children with IgA nephropathy

BackgroundBecause moderate or severe proteinuria is a representative factor indicative of longterm poor prognosis in IgA nephropathy, an anti-proteinuric treatment which can be administered longterm with few side effects is necessary. We report here a comparison of antiproteinuric effects in two patient groups treated with different combination therapies.MethodsGroup A comprised 12 patients with IgA nephropathy, who had 24-h proteinuria of 0.5 gm2 or more, moderately severe renal histology, and normal renal function, and were treated with a combination of drugs, i.e., prednisolone, an immunosuppressant (mizoribine), an anti-platelet drug (dipyridamole), and an angiotensin-converting enzyme inhibitor. Group B consisted of 18 patients who had baseline characteristics similar to those of the patients in group A and were treated with our previous protocol (a combination of prednisolone, cyclophosphamide, and dipyridamole). Twenty-four-hour proteinuria and creatinine clearance were measured every 6 months. The primary endpoint was reduction of 24-h proteinuria by less than 25% compared with the baseline value.ResultsThe proportion of patients that exhibited the primary endpoint, as assessed by the Kaplan-Meier method, was found to be significantly higher in group A than in group B (logrank test; P = 0.024). None of the patients in the two groups experienced serious adverse effects.ConclusionsThe results suggested that the use of drugs in combination with cyclophosphamide was beneficial for patients with moderately severe IgA nephropathy.

Promotion of survival and prevention of apoptosis in rat mesangial cells by a membrane-anchored form of heparin-binding EGF-like growth factor

AbstractBackground. We previously demonstrated that heparin-binding epidermal growth factor-like growth factor (HB-EGF) was expressed in rat mesangial cells and was involved in the progression of of glomerulonephritis in human and animal models. Soluble HB-EGF promotes cultured rat mesangial cell proliferation and the synthesis of type I and type III collagen mRNA. However, the precise role of proHB-EGF in mesangial cell function has not yet been clarified. In the present study, we address this question. Methods. ProHB-EGF-transfected rat mesangial cells (MsC; MsCproHB-EGF) and empty vector-transfected rat MsC (MsCvector) were constructed. Cells were cultured in fetal calf serum (FCS)-containing (10%) or FCS-deficient medium, and the growth rates and numbers of surviving cells were determined. To elucidate the anti-apoptotic effect of proHB-EGF, cells were exposed to hydrogen peroxide (H2O2) or dexamethasone (DEX). Apoptosis was identified by qualitative and quantitative analysis. Expression of Bcl-2 protein in MsCproHB-EGF after exposure to apoptosis inducers was also evaluated. Results. When cells were plated in a medium containing 10% FCS, the growth rate of MsCproHB-EGF was not different from that of MsC transfected with a plasmid alone (MsCvector). When cultured in the absence of FCS, MsCvector showed decreased cell numbers, indicating apoptotic cell death. In contrast, MsCproHB-EGF formed small colonies, although they did not show increased cell numbers, while cell viability was 90%–100% of the initial cell number after subculture. When quiescent MsC were exposed to DEX or H2O2, MsCvector exhibited significant DNA laddering, whereas MsCproHB-EGF showed resistance to these stimuli. The release of caspase-3 from MsCproHB-EGF after exposure to DEX or H2O2 was significantly lower than that from MsCvector. Bcl-2 protein expression was weak in MsCproHB-EGF at the baseline, but this expression was significantly upregulated after exposure to these stimuli. Confluent MsCproHB-EGF spontaneously expressed high level of p21 protein. Northern blot analysis revealed that MsCproHB-EGF expressed increased levels of type I and type III collagen mRNA and proteins compared with those of MsCvector. Conclusions. These results indicate that proHB-EGF contributes to mesangial cell survival by promoting cell viability and by inhibiting apoptosis. The anti-apoptotic effect of proHB-EGF could be closely related to the upregulation of Bcl-2 and p21 expression.