Faculty Profiles - TSUKAHARA Hirokazu

Ultrasound Diagnosis of Ureteric Reflux in Infants with Urinary Infection.

Hiraoka Masahiro, Hashimoto Gotaro, Hayashi Shuhei, Hori Chikahide, Tsuchida Shinya, Tsukahara Hirokazu, Sudo Masakatsu

Nihon Shoni Jinzobyo Gakkai Zasshi 8 ( 2 ) 191 - 193 1995

Measurement of urinary fibrin/fibrinogen degradation products revisited and re‐emphasized

HIROKAZU TSUKAHARA, TOSHIHARU OKADA, CHIKAHIDE HORI, SHINYA TSUCHIDA, MASAHIRO HIRAOKA, MASAKATSU SUDO

Pediatrics International 37 ( 1 ) 120 - 121 1995

Morphological characterization of glomerular endothelial cells cultured on a basement membrane matrix

Shinya Tsuchida, Masahiro Hiraoka, Hirokazu Tsukahara, Akira I. Negami, Toshiro Tominaga, Masakatsu Sudo

The Japanese Journal of Nephrology 36 ( 1 ) 1 - 8 1994

Language：English Publishing type：Research paper (scientific journal)

We characterized the morphological expression of glomerular endothelial cells (GEC) cultured on a basement membrane matrix, Matrigel. GEC cultured on this matrix formed abundant networks of branching and anastomosing cords of cells, and formed capillary-like structures with a lumen and interdigitating junctional processes. In contrast, GEC cultured on fibronectin-coated dishes had elongated spindle shapes without any interdigitating junctional processes. These findings suggest that the culture system with Matrigel is useful for inducing and maintaining characteristics close to in vivo GEC. © 1994, Japanese Society of Nephrology. All rights reserved.

DOI： 10.14842/jpnjnephrol1959.36.1

Urinary N‐acetyl‐beta‐D‐glucosaminidase excretion in term and preterm neonates

H. TSUKAHARA, C. HORI, S. TSUCHIDA, M. HIRAOKA, M. SUDO, S. HARUKI, F. SUEHIRO

Journal of Paediatrics and Child Health 30 ( 6 ) 536 - 538 1994

Language：English Publishing type：Research paper (scientific journal)

Urinary N‐acetyl‐beta‐D‐glucosaminidase (NAG) excretion was measured in term and preterm neonates on days 1, 4, 7, 14 and 28 of life. Urinary NAG showed a peak level on day 4 or 7 in these infants. In addition, it tended to be higher with the degree of prematurity. In sick preterms who were depressed at birth and had respiratory failure, the NAG activity was further elevated during the first 2 weeks, suggesting the presence of renal tubular injury in this period. These observations thus suggest that urinary NAG may be a sensitive measure of renal maturation or damage in neonates. Copyright © 1994, Wiley Blackwell. All rights reserved

DOI： 10.1111/j.1440-1754.1994.tb00729.x

Ultrasonographic evaluation of bladder volume in children

Masahiro Hiraoka, Hirokazu Tsukahara, Shinya Tsuchida, Chikahide Hori, Masakatsu Sudo

Pediatric Nephrology 7 ( 5 ) 533 - 535 1993.10

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer-Verlag

Although ultrasound has been recently used to estimate bladder volume, several different formulae are used. We analysed the accuracy of ultrasound evaluation of bladder volume with an ultrasound scanner equipped with a videocassette recorder. We determined three dimensions of the bladder, i.e. depth (D), height (H) and width (W) by reviewing videotapes in 53 children. D×H×W (DHW) showed a good linear relationship with actual bladder volume (r=0.96). Estimation of bladder volume by the regression equation gave errors of 12.5±8.6% (mean±SD) with errors above 25% in only 6% of children. Estimation of the volume by simply multiplying DHW by a correction factor of 0.80 gave a greater error of 18.9±14.0% (P&lt
0.001) with errors above 25% in 24% of children. Thus, the use of the formula volume (ml)=DHW (cm3)×0.68+4 was sufficiently accurate in the ultrasound estimation of bladder volume in children. © 1993 IPNA.

DOI： 10.1007/BF00852537

Clinical course and outcome of idiopathic membranous nephropathy in Japanese children

Hirokazu Tsukahara, Yasuo Takahashi, Masahiro Yoshimoto, Shuhei Hayashi, Shinichi Fujisawa, Fumihiko Suehiro, Kyoji Akaishi, yasuyuki Nomura, Kiyoshi Morikawa, Masakatsu Sudo

Pediatric Nephrology 7 ( 4 ) 387 - 391 1993.8

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer-Verlag

We retrospectively studied 12 Japanese children (8 boys, 4 girls) with idiopathic membranous nephropathy (IMN), aged 2.9-15.8 (mean 7.7) years at onset. All patients were identified through either screening or a routine urinalysis
proteinuria was present in all, haematuria, which was macroscopic in 4, in 11. Three had nephrotic syndrome (NS) at or soon after onset. Stages on electron microscopy, performed in 10 patients, were I in 3, II in 5 and III in 2. Steroids alone or with cyclophosphamide were administered to 5 patients, including the 3 patients showing NS. Complete remission of proteinuria occurred in 8 patients 0.3-1.6 (mean 0.6) years after onset, and proteinuria did not recur. After a follow-up of 1.6-11.6 (mean 5.9) years, these 8 patients were in complete remission and the remaining 4 had only mild proteinuria
none had hypertension or impaired renal function. Thus, we infer that IMN in Japanese children may have a better course and outcome than IMN in non-Japanese children. Based on a comparative study of Japanese (previously reported cases added to ours) and non-Japanese (mostly Caucasian) children with IMN, this was confirmed: it is possible that steroid therapy in Japanese patients is more effective in inducing remission of NS and preserving renal function. © 1993 IPNA.

DOI： 10.1007/BF00857546

Urinary α1 as an index of proximal tubular function in early infancy

Hirokazu Tsukahara, Masahiro Hiraoka, Masanori Kurivama, Masakazu Saito, Kiyoshi Morikawa, Mitsuhiko Kuroda, Toshiro Tominaga, Masakatsu Sudo

Pediatric Nephrology 7 ( 2 ) 199 - 201 1993.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer-Verlag

Urinary α1-microglobulin (U-A1M) was measured in healthy term infants on days 1, 4, 7, 14, 28, 90 and 180 of life. U-A1M was high until day 14 and declined thereafter. It was significantly correlated with urinary β2-microglobulin (U-B2M) throughout the study, but not with serum A1M on days 1 or 7. Similar to U-B2M, U-A1M in the clinically stable term infants with intrauterine growth retardation (n=4-7) was not elevated on days 1-7. In the sick infants who needed immediate resuscitatio at birth (n=4-8), U-A1M as well as U-B2M was high on days 1-7 and then decreased to normal levels, suggesting that U-A1M can be used as a sensitive marker of acute proximal tubular damage and its recovery. These observations indicate that U-A1M is a useful index of proximal tubular function in early infancy. © 1993 IPNA.

DOI： 10.1007/BF00864399

Urinary growth hormone excretion in preterm neonates

Hirokazu Tsukahara, Yasushi Fujii, Masanori Kuriyama, Shinya Tsuchida, Masahiro Hiraoka, Kiyoshi Kikuch, Masakatsu Sudo

Neonatology 63 ( 1 ) 8 - 13 1993

Language：English Publishing type：Research paper (scientific journal)

We measured urinary growth hormone (U-GH), β&lt
inf&gt
2&lt
/inf&gt
micro-globulin (U-B2) and serum growth hormone (S-GH) in preterm neonates on days 1. 4, 7, 14 and 28 of age. U-GH as well as U-B2 were high, particularly in the more premature and sick neonates with respiratory failure requiring mechanical ventilation. U-GH showed significant positive correlations with U-B2 throughout the study but with S-GH only on day 7. Therefore, we conclude that in preterm neonates, U-GH mainly reflects the degree of renal proximal tubular function, which is determined by the degree of renal maturation of the subject and of tubular injury due to disease states such as respiratory failure. © 1993 S. Karger AG, Basel.

DOI： 10.1159/000243902

Evaluation of proximal tubular function in preterm infants by urinary α1‐microglobulin

HIROKAZU TSUKAHARA, MASAHIRO HIRAOKA, MASANORI KURIYAMA, SHINICHI HARUKI, KATSUJI NAKAMURA, FUMIHIKO SUEHIRO, MASAKATSU SUDO

Pediatrics International 35 ( 2 ) 127 - 129 1993

Language：English Publishing type：Research paper (scientific journal)

α 1‐Microglobulin is a low molecular weight protein that is relatively stable in urine of low pH. There have been few reports on urinary α1‐microglobulin (U‐A1M) excretion in preterm infants. This study was designed to establish the ranges for U‐A1M in clinically stable preterm infants and to investigate changes observed in sick preterm infants. We measured U‐A1M and urinary β2‐microglobulin (U‐B2M) levels at 1, 4, 7, 14, 28 and 90 days after birth in stable preterm infants (Group 1) and sick preterm infants who were depressed at birth and required immediate resuscitation (Group 2). In Group 1 infants, both parameters were high during the first 28 days and appeared to decline thereafter. U‐A1M in Group 2 infants was only significantly increased compared with Group 1 on day 1, as was U‐B2M. On each day of the study, U‐A1M had significant positive correlations with U‐B2M for all the infants studied. The changes of the two parameters observed in Group 1 probably reflect postnatal evolution of proximal tubular function in stable preterm infants. A comparison of groups 1 and 2 shows a high prevalence of acute tubular injury at birth in sick infants and also suggests that U‐A1M as well as U‐B2M may be a sensitive index for detecting acute tubular damage and for following its course in preterm infants. 1993 Japan Pediatric Society

DOI： 10.1111/j.1442-200X.1993.tb03022.x

小児における部位別骨塩定量:DEXAを用いて Reviewed

塚原宏一, 高野智子, 中井昭夫, 平岡政弘, 須藤正克, 梅崎実, 中島鉄夫, 山本和高, 石井靖, 春木伸一

日本小児放射線学会雑誌 8 216 - 219 1992

Dual-Energy X-ray Absorptiometry(DEXA)の小児への応用 Reviewed

塚原宏一, 藤井靖史, 栗山政憲, 平岡政弘, 中井昭夫, 須藤正克, 中島鉄夫, 梅崎実, 山本和高, 石井靖, 森河浄, 林修平, 春木伸一

日本小児放射線学会雑誌 8 70 - 71 1992

Urinary Growth Hormone Excretion in Renal Disease

Hirokazu Tsukahara, Shinya Tsuchida, Masahiro Hiraoka, Kiyoshi Morikawa, Kiyoshi Kikuchi, Masakatsu Sudo

Pediatrics International 34 ( 1 ) 92 - 95 1992

Urinary Fibrin and Fibrinogen Degradation Products and the Origin of Hematuria

Hirokazu Tsukahara, Masahiro Hiraoka, Masakatsu Sudo, Toshiharu Okada, Kiyoshi Morikawa, Mitsuhiko Kuroda

Pediatrics International 34 ( 5 ) 525 - 529 1992

Language：English Publishing type：Research paper (scientific journal)

We examined urinary fibrin and fibrinogen degradation product (U‐FDP) concentrations in pediatric patients with hematuria using the rapid and highly‐sensitive latex particle agglutination test (LPAT), and assessed the value of this test for the localization of the site of hematuria. Patients with hematuria were divided into two groups: 60 with glomerular hematuria and 46 with non‐glomerular hematuria. If U‐FDP concentrations less than 0.25 μg/ml are Accepted as an indicator of glomerular bleeding, the sensitivity and specificity of localization of glomerular hematuria in the present study were 78% (47/60) and 89% (41/46), respectively. The high U‐FDP concentrations observed in patients with non‐glomerular hematuria may reflect direct bleeding into the urinary tract. Since all 13 patients with glomerular hematuria and U‐FDP concentrations of 0.25 μg/ml or more had coexistent erythrocyte cylindruria, the U‐FDP test seems to be compensated with combined urinalysis for the relatively lower sensitivity. We conclude that a knowledge of U‐FDP concentrations by LPAT can be of help in localizing the site of bleeding in hematuria. Copyright © 1992, Wiley Blackwell. All rights reserved

DOI： 10.1111/j.1442-200X.1992.tb01000.x

Congenital Hydrocolpos Combined with Unilateral Renal Agenesis

Hirokazu Tsukahara, Iwao Fujimoto, Masahiro Hiraoka, Tetsuo Nakashima, Nobushige Hayashi, Yasushi Ishii, Masakatsu Sudo

Pediatrics International 33 ( 6 ) 729 - 733 1991

Language：English Publishing type：Research paper (scientific journal)

Herein we report an infantile case of congenital hydrocolpos combined with left renal agenesis which presented with an abnormal mass protruding from the vaginal introitus. The diagnosis was made shortly after birth by ultrasonography and confirmed by other radiologic diagnostic methods. This case highlights the value of ultrasonography in diagnosing hydrocolpos and determining the coexistence of renal anomalies. Copyright © 1991, Wiley Blackwell. All rights reserved

DOI： 10.1111/j.1442-200X.1991.tb02599.x

Evaluation of Lumbar Bone Mineral Density by Dual Energy X‐Ray Absorptiometry

Hirokazu Tsukahara, Tetsuo Nakashima, Masahiro Yoshimoto, Masanori Kuriyama, Yosuke Shigematsu, Shuhei Hayashi, Shinichi Haruki, Yasushi Ishii, Masakatsu Sudo

Pediatrics International 33 ( 4 ) 459 - 466 1991

Language：English Publishing type：Research paper (scientific journal)

Using dual‐energy x‐ray absorptiometry (DEXA), the lumbar spinal bone mineral density (BMD) in 49 Japanese children with or without metabolic bone disease (MBD) was determined. The following results were obtained: (a) The normal data for healthy Caucasians (J Clin Endocrinol Metab 1990
70: 1330‐1333) appear to be applicable to Japanese children
(b) BMD was normal in patients with congenital hydronephrosis with normal renal function
(c) One patient with congenital renal failure and one with Lowe syndrome had low BMD, but the MBD in the former improved markedly with peritoneal dialysis
(d) A reduced BMD was found in patients treated with long‐term steroids, probably because of decreased turnover of bone
(e) A reduction in BMD was pronounced in preterm infants during the first few months of life. In conclusion, DEXA is a useful method of bone densitometry in MBD in children. Copyright © 1991, Wiley Blackwell. All rights reserved

DOI： 10.1111/j.1442-200X.1991.tb02572.x

Assessment of tubular function in neonates using urinary β2-microglobulin

Hirokazu Tsukahara, Masahiro Yoshimoto, Masakazu Saito, Tadahiko Sakaguchi, Izuru Mitsuyoshi, Syuhei Hayashi, Katsuji Nakamura, Kiyoshi Kikuchi, Masakatsu Sudo

Pediatric Nephrology 4 ( 5 ) 512 - 514 1990.9

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer-Verlag

Renal proximal tubular function was assessed in neonates by measuring urinary β2-microglobulin (β2M) concentrations on days 1, 4, 7, 14 and 28. Values were elevated in stable preterm low-birthweight (LBW) neonates but not in stable term LBW neonates, suggesting that proximal tubular maturation is related to gestational age rather than birthweight. The urinary β2M was significantly increased on day 1 in neonates with the meconium aspiration syndrome but was not significantly different from normal subsequently. This indicated that although the proximal tubular cells may be susceptible to perinatal hypoxia, they maintain a remarkable capacity to recover in a relatively short period. Neonates with transient tachypnoea of the newborn had normal urinary levels of β2M indicating their renal tubular function was not impaired. © 1990 IPNA.

DOI： 10.1007/BF00869835

Evaluation of variability of proteinuria indices

Masahiro Yoshimoto, Hirokazu Tsukahara, Masakazu Saito, Shuhei Hayashi, Shinichi Haruki, Shinichi Fujisawa, Masakatsu Sudo

Pediatric Nephrology 4 ( 2 ) 136 - 139 1990.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer-Verlag

We compared several indices of proteinuria, namely protein concentration, hourly protein excretion rate (Up/h) and protein/creatinine ratio (Up/Ucr) in single voided urine samples as well as 24 h-urinary protein excretion (24 h-Up), in 44 children, aged 4-16 years, with varying degrees of urinary protein excretion. We found an excellent correlation between Up/h and Up/Ucr in early morning samples. These two indices in early morning samples had excellent correlation with 24 h-Up, comparable to those in any other urine sample of the day. Among daytime samples, Up/h varied widely, in contrast to Up/Ucr, which had significantly less variability. We analysed six early morning and six bedtime samples from 39 of these subjects, and found smaller coefficients of variation for individual patient's indices in morning samples. Up/h was more variable than Up/Ucr, especially in bedtime samples. Urinary protein concentration had a poorer correlation with 24 h-Up and was more variable than any other index. We conclude that the Up/Ucr in early morning samples, which has the advantages both of simplicity and low day-to-day variability in a given patient, is a superior index of proteinuria. © 1990 IPNA.

DOI： 10.1007/BF00858824

Urinary Growth Hormone during Early Infancy: Another Index of Proximal Tubular Function Reviewed

Hirokazu Tsukahara, Kiyoshi Kikuchi, Katsuji Nakamura, Masahiro Yoshimoto, Masakazu Saito, Masakatsu Sudo

Pediatrics International 32 ( 5 ) 575 - 578 1990

Juvenile Nephronophthisis Diagnosed from Glucosuria Detected by Urine Screening at School Reviewed

Hirokazu Tsukahara, Kiyoshi Kikuchi, Haruki Mikawa, Shinichi Fujisawa, Masahiro Yoshimoto, Masakatsu Sudo

Pediatrics International 32 ( 5 ) 548 - 551 1990

Language：English Publishing type：Research paper (scientific journal)

We describe the case of an 11‐year‐old girl in whom glucosuria detected by urine screening at school was the first clue to the diagnosis of juvenile nephronophthisis (JN). On admission, she showed renal failure with combined proximal and distal tubular defects and progressive deterioration of renal function. JN should be considered in children with glucosuria. Copyright © 1990, Wiley Blackwell. All rights reserved

DOI： 10.1111/j.1442-200X.1990.tb00878.x