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Biomedical subjects

I S Ha

Publications and source records attributed to I S Ha.

15 recordsLinked to original sources
PubMed2001

Ifosfamide nephrotoxicity in pediatric cancer patients.

The renal functions in pediatric cancer patients who received ifosfamide (IFO) treatment were evaluated and the risk factors related to IFO nephrotoxicity were determined. The medical records of all children treated with IFO were reviewed, and 62 with normal renal function before IFO treatment were selected. Nephrotoxicity was diagnosed by measuring urine beta2-microglobulin and glucose, and serum phosphate, bicarbonate, and creatinine. Forty-eight (77.4%) had a history of previous cisplatin treatment. Nephrotoxicity was detected in 20 patients (32.3%). beta2-Microglobulinuria was observed in all 20, hypophosphatemia in 10 (16.1%), hypocarbia in 2 (3.2%), glucosuria in 5 (8.1%), and decreased creatinine clearance in 7 (11.3%). The cumulative dose of IFO and a history of previous cisplatin therapy were related to nephrotoxicity. Among the 20 patients with nephrotoxicity, the median cumulative dose of IFO in patients with a low (<500 mg/m2) and high (>500 mg/m2) cumulative dose of previous cisplatin was 80 g/m2 (73-102 g/m2) and 45 g/m2 (11-76 g/m2), respectively. Most of the nephrotoxicity persisted after cessation of IFO treatment. In conclusion, close monitoring of IFO nephrotoxicity should be started earlier in patients with high-dose cisplatin pretreatment. Tubular proteinuria, as indicated by beta2-microglobulinuria, was the most-sensitive marker for IFO nephrotoxicity. Long-term follow-up study for reversibility of IFO nephrotoxicity is in progress.

Adolescent↗
PubMed2000

Mutational analysis of COL4A5 gene in Korean Alport syndrome.

Mutational analysis of the COL4A5 gene in X-linked Alport syndrome (AS) requires an expensive and time-consuming procedure with a detection rate of 50%, at best. There have been three multicenter collaborative studies of mutation analysis in the COL4A5 gene using systematic screening of entire coding regions of the gene. This is a similar study executed in a single center in Korea. Twenty-five unrelated Korean patients with AS in whom the diagnosis was confirmed pathologically were included in the study. By systematic screening of all 51 exons of the gene using polymerase chain reaction/single-strand conformation polymorphism analysis, ten mutations were detected in 10 unrelated patients. These included one medium-sized deletion involving exon 49-51, one single base pair deletion, one nonsense point mutation, one splice site mutation, and six missense point mutations. Of the six missense mutations, four involved a glycine residue and disrupted the Gly-X-Y repeats in the collagenous domain. The overall detection rate of mutations was 40%. Although DNA analysis in AS is currently not applicable to routine clinical diagnosis due to several practical and technical problems, it is likely to replace morphological diagnosis in the near future.

Adolescent↗
PubMed2000

Early recurrent nephrotic syndrome after renal transplantation in children with focal segmental glomerulosclerosis.

BACKGROUND: We analysed risk factors to predict the recurrence of nephrotic syndrome and the therapeutic efficacy of plasmapheresis combined with oral cyclophosphamide (PE+CPM) in early recurrent nephrotic syndrome after transplantation in children with focal segmental glomerulosclerosis (FSGS). METHODS: Medical records after 1990 of 16 children with biopsy-proven idiopathic FSGS and renal transplantation before the age of 18 years were reviewed. RESULTS: Early recurrence of nephrotic syndrome developed in six cases (37. 5%). While early kidney graft biopsies, performed within the first week after the onset of recurrence, revealed diffuse effacement of foot process only, late biopsies contained segmentally sclerosed glomeruli as well. Among several possible risk factors, the mean duration from onset of original nephrotic syndrome to development of end-stage renal disease was shorter in the recurrent group (P=0.045) and the percentage of globally sclerosed glomeruli was higher in the non-recurrent group (P=0.001). PE+CPM therapy resulted in complete remission of nephrotic syndrome if it was started early and if there was no evidence of accompanying acute rejection. CONCLUSION: These results support more liberal use of living-related donors for renal transplantation of children with FSGS and ESRD, considering the shortage of cadaveric donors in our society and relatively good efficacy of the early and intensive PE+CPM therapy for early recurrent nephrotic syndrome.

Adolescent↗
PubMed2000

Association of angiotensin I converting enzyme gene polymorphism with reflux nephropathy in children.

Deletion polymorphism of angiotensin I converting enzyme (ACE) gene has been studied as a risk factor in various cardiovascular diseases and chronic nephropathies. Perturbation of local and systemic renin-angiotensin systems is one of the possible mechanisms of the progression of reflux nephropathy. In this study, the implication of ACE gene polymorphism in renal scarring and deterioration of renal function was analyzed in 66 children with vesicoureteral reflux. The genotype for the polymorphism was determined by PCR, and renal scar was identified by (99m)Tc-DMSA renal scan. The allelic frequency of the deletion polymorphism showed no significant difference either between patients with normal renal function and those with decreased renal function or between patients with renal scar and those without. We conclude that deletion polymorphism of ACE gene, as an independent variable, is not associated with reflux nephropathy in children with vesicoureteral reflux.

Adolescent↗
PubMed1999

Hereditary glomerulopathy associated with a mitochondrial tRNA(Leu) gene mutation.

Several cases of hereditary glomerulopathy associated with an A to G transition at position 3243 in mitochondrial DNA, which is known to be associated with most cases of MELAS syndrome (myopathy, encephalopathy, lactic acidosis, and stroke-like episodes), have been recently reported. These patients share the characteristics of hereditary progressive glomerular disease and hearing loss with Alport syndrome. We therefore screened 27 patients with kidney disease clinically mimicking Alport syndrome for the presence of the 3243 mitochondrial mutation, and found one girl with the mutation and a positive family history. Her clinical features were very similar to those of all cases reported to date. An absence of hematuria, severe kidney involvement in a female, pathological changes of focal segmental glomerulosclerosis with no basket-weave change of the glomerular capillary wall, and the frequent association of steroid-induced diabetes are the major features that distinguish this condition from Alport syndrome. Careful neurological examination may detect neuromuscular symptoms compatible with mitochondrial cytopathies. In conclusion, progressive glomerulopathy should be included in the broad spectrum of mitochondrial cytopathies, especially in cases of MELAS syndrome. This mutation should also be included in the etiologies of secondary focal segmental glomerulosclerosis and in the differential diagnosis of Alport syndrome.

Adolescent↗
PubMed1997

Six novel mutations in the vasopressin V2 receptor gene causing nephrogenic diabetes insipidus.

X-linked nephrogenic diabetes insipidus (NDI) is a rare disease caused by mutations in the vasopressin V2 receptor (AVPR2) gene. We analyzed the AVPR2 gene in 6 unrelated Korean families with X-linked NDI, and found 6 novel mutations. Two of them were missense point mutations, 2 were short deletions causing frameshifts, 1 was a duplication of 9 bases, and 1 was a compound gene rearrangement. Four mutations cosegregated with the clinical phenotype in corresponding family members, and one was a de novo mutation. In 1 family, prenatal diagnosis was made by amniocentesis. In conclusion, we found 6 novel mutations in the AVPR2 gene causing X-linked NDI in 6 families, and direct mutational analysis is now applicable for carrier detection and early (prenatal) diagnosis.

Adult↗
PubMed1996

Diagnosis of Yersinia pseudotuberculosis infection by polymerase chain reaction.

BACKGROUND: The diagnosis of Yersinia pseudotuberculosis infection is usually based on serologic and/or bacteriologic tests. However, successfully culturing Y. pseudotuberculosis is difficult, and serologic tests in many cases require at least two serial sera obtained during 1-week intervals to confirm rising agglutination antibody titers. METHODS: We applied a nested polymerase chain reaction method for rapid diagnosis of Y. pseudotuberculosis infection. The DNAs extracted from the peripheral blood and urine of patients and from mountain water, a suspected source of infection, were used as templates for the polymerase chain reaction with consequent amplification of a fragment of the inv gene in the chromosomal DNA of Y. pseudotuberculosis. RESULTS: The overall rate of diagnosis with the polymerase chain reaction, which was based on a positive result with a single blood sample or one or more positive results with serial samples, was 93.3%. The polymerase chain reaction was also positive in two mountain water samples that were thought to be a source of infection. CONCLUSION: Based on our results the nested polymerase chain reaction method can be used clinically for rapid and precise diagnosis of Y. pseudotuberculosis infection.

Base Sequence↗
PubMed1996

Complement 4 locus II gene deletion and DQA1*0301 gene: genetic risk factors for IgA nephropathy and Henoch-Schönlein nephritis.

There have been several reports suggesting that the deficiency of complement 4 (C4) and/or deletion of C4 genes are the genetic risk factors in patients with IgA nephropathy (IgAN) and Henoch-Schönlein nephritis (HSN). In the current study, we tried to clarify the genetic structure of deleted C4 genes as well as the isotype deficiency of the patients. Also, we investigated the DQB and DRB genes which are located near the C4 genes to identify a possible linkage and to find the associated allele. Our results showed that locus II deletion of C4, not the C4B sequence loss, is a risk factor for these diseases and the deleted gene can be either C4A or C4B. There was no specific isotype deficiency or specific allotype which was significantly increased or decreased in the patients. But, there was an increased frequency of DQA1*0301 gene in the patient group (corrected p = 0.04), which suggests that DQA1*0301 as well as C4 gene deletion could be genetic risk factors for these diseases.

Adult↗
PubMed1995

Development of monoclonal antibodies against Hantaan virus nucleocapsid protein.

Forty-five hybridoma cell lines producing monoclonal antibodies against Hantaan virus, the etiologic agent of hemorrhagic fever with renal syndrome, were generated by fusion of P3-X63-Ag8.V653 myeloma cells with spleen cells of mice immunized with inactivated Hantaan virus vaccine. Among these, 38 antibodies were identified as binding to the 48-kDa nucleocapsid protein by immunoblot assay or radioimmunoprecipitation. Twenty-six of them were of the immunoglobulin G1 (IgG1), nine were of the IgG2a, and three were of the IgA isotype. According to cross-reactivities with other serotypes of the genus Hantavirus, the antibodies were classified into three groups: 6 antibodies specific to the Hantaan serotype (group I), 20 antibodies cross-reacting with Hantaan and Seoul serotypes (SR-11, Tchoupitoulas, and R22) (group II), and 12 antibodies cross-reacting with Hantaan, Seoul, and Prospect Hill serotypes (group III). None of the antibodies cross-reacted with the Puumala serotype. With a panel of antibodies of different cross-reactivities, serotypes of Hantavirus could be differentiated. Thirty-eight monoclonal antibodies against Hantaan virus nucleocapsid protein which have different cross-reactivities between serotypes were developed. These results confirmed the presence of multiple serotype-specific epitopes on the nucleocapsid protein of Hantaan virus, which can be utilized in differentiation of serotypes.

Animals↗
PubMed1995

Acute renal failure associated with Yersinia pseudotuberculosis infection.

Since 1987, we have experienced 11 children with acute renal failure (ARF) associated with Yersinia pseudotuberculosis (YP) infection. The illness began with the sudden onset of high fever, skin rash and gastrointestinal symptoms. Later in the course, periungual desquamation developed, mimicking Kawasaki disease. Elevated erythrocyte sedimentation rate, C-reactive protein and thrombocytosis were noticeable, and mild degrees of proteinuria, glycosuria and sterile pyuria were common. ARF, which typically developed about 1-3 weeks after the onset of fever, underwent a benign course with complete recovery. The renal biopsies mainly revealed findings of acute tubulointerstitial nephritis. YP should be considered as one of the causes of acute tubulointerstitial nephritis causing ARF, especially in children.

Acute Kidney Injury↗
PubMed1993

Partial hypoxanthine-guanine phosphoribosyl transferase deficiency in two Korean siblings--a new mutation.

Two Korean siblings with partial hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency are reported. The index patient was a boy aged 9 years 10 months who developed acute renal failure with a serum uric acid level of 25.9 mg/dl, after vomiting. The younger brother was asymptomatic but had elevated serum uric acid (9.4 mg/dl). The red blood cell HPRT activity of both siblings was one-tenth of normal. Analysis of genomic DNA revealed a point mutation from A (adenine) to G (guanine) at nucleotide position 215 on exon 3; this is a new mutation. The younger brother had the same mutation and the mother was heterozygous for this mutation.

Acute Kidney Injury↗
PubMed1992

HLA-DR expression in human fetal thymocytes.

We analyzed the expression of MHC class I (W6/32) and class II (HLA-DR) antigens on human fetal and postnatal thymocytes by fluorescence-activated cell sorting. Less than 5% of prenatal thymocytes expressed HLA-DR before week 12 of gestation. However, the number of HLA-DR-positive cells significantly increased during the late second and third trimester of gestation, when greater than 50% of prenatal thymocytes expressed HLA-DR. Such high-level expressions of HLA-DR in fetal thymocytes were also demonstrated by Northern-blot analysis and immunohistochemistry. After birth, the percentage of HLA-DR-positive cells in thymocytes decreased gradually. A high-level expression of class I antigen was also observed in thymocytes from the early stages of gestation, but, in contrast to MHC class II, a majority of postnatal thymocytes maintained high levels of class I antigen after birth.

Cell Separation↗
PubMed1987

Childhood renal diseases in Korea. A clinicopathological study of 657 cases.

Between June 1975 and March 1987, 662 renal biopsies were performed in 657 children at Seoul National University Children's Hospital. Nephrotic syndrome was the most indication for renal biopsy and accounted for 62% of all cases. Of these, 57% showed minimal change lesions and 21% showed focal segmental glomerular sclerosis. Nephropathy, associated with Australia-antigen-positive hepatitis, was the most prominent cause of secondary nephrotic syndrome, and of these patients membranous nephropathy was found in 86%. Diffuse proliferative glomerulonephritis was found in 60% of patients with acute nephritic syndrome. Fifty-eight percent of children with haematuria were found to have either IgA nephropathy or Henoch-Schönlein nephritis. Fifteen children with acute renal failure were biopsied, 2 of whom had haemorrhagic fever.

Child↗
PubMedDate not supplied

Circulating VEGF and TGF-beta1 in children with idiopathic nephrotic syndrome.

RATIONALE: The implications of vascular endothelial growth factor (VEGF) and transforming growth factor-beta (TGF-beta) on the development of proteinuria were studied by measuring the mRNA and protein levels of VEGF and TGF-beta1 in 43 children with primary nephrotic syndrome. METHODS: Twenty-seven patients were in the active nephrotic phase at the time of sampling (Group 1), and 16 were in remission (Group 2). In Group 1, 16 were steroid-responders (Group 1a) and 11 were nonresponders (Group 1b). Minimal change lesion (MCL) in 11 patients and focal segmental glomerulosclerosis (FSGS) in 8 were confirmed by renal biopsy. The mRNA expressions of peripheral blood lymphocytes and the plasma levels of proteins were measured by semi-quantitative RT-PCR and ELISA, respectively. RESULTS: Plasma VEGF concentration was higher in Group 1 (204+/-137 pg/mL) than Group 2 (91+/-72 pg/mL) (P=0.002). However, there was no significant difference either between Group 1a (184+/-146 pg/mL) and Group 1b (258+/-134 pg/mL) or between patients with FSGS (330+/-122 pg/mL) and those with MCL (146+/-112 pg/mL). The VEGF mRNA expression showed changes similar to VEGF protein expression, and there was no statistical significance. Plasma levels and mRNA expressions of TGF-beta1 were similar in all groups. CONCLUSIONS: These results suggest that circulating VEGF is associated with proteinuria both in steroid-responsive and steroid-resistant primary nephrotic syndrome in children.

Adolescent↗