Biomedical subjects

Y K Tsau

Publications and source records attributed to Y K Tsau.

At least 19 recordsLinked to original sources

PubMed2001

Nephromegaly and elevated plasma hepatocyte growth factor-transforming growth factor-beta1 ratio in infants with fulminant hepatitis or biliary atresia.

Nephromegaly, assessed by calculating kidney volume using renal ultrasound, was studied in infants with biliary atresia, neonatal hepatitis, or fulminant hepatitis. We evaluated kidney volume in 29 patients with biliary atresia, 17 patients with neonatal hepatitis, and 10 patients with fulminant hepatitis, as well as 32 healthy infants. Levels of plasma hepatocyte growth factor (HGF) were measured in all infants. Levels of plasma transforming growth factor-beta1 (TGF-beta1) were also measured in diseased infants and 20 healthy infants. Significant nephromegaly was found in infants with biliary atresia compared with healthy infants (P < 0.001 by analysis of covariance). Marked nephromegaly was also noted in all infants with fulminant hepatitis and 35% of infants with neonatal hepatitis. No nephromegaly was found in infants at 2 months of age with biliary atresia or neonatal hepatitis despite mildly elevated plasma HGF levels. Regardless of the duration of HGF exposure and healthy renal growth by a certain age, a positive correlation existed between plasma HGF level and kidney volume (r = 0.529; P < 0.001), but an inverse correlation was found between plasma TGF-beta1 level and nephromegaly (r = -0.505; P < 0.001) in all diseased infants. There was a stronger positive correlation between plasma HGF-TGF-beta1 ratio and kidney volume (r = 0.666; P < 0.001) and degree of nephromegaly (r = 0.717; P < 0.001). These results confirm the presence of large kidneys not only in patients with biliary atresia but also in patients with fulminant hepatitis, which suggests the possible pathogenic role of HGF and manifests as elevated HGF-TGF-beta1 ratios in patients with such conditions. Nephromegaly in patients with severe or chronic liver dysfunction may provide a new in vivo model to study the mechanisms of renal growth.

Biliary Atresia↗

PubMed2001

Paraganglioma manifesting as shock: a case report.

Paraganglioma is a rare neuroendocrine tumor in children that rarely manifests as shock. We describe the case of a 12-year-old girl with paraganglioma who developed impaired cardiac function, pulmonary edema, and shock at the time of admission. Her blood pressure stabilized after intravenous normal saline rescue and dopamine treatment. However, hypertension was noted thereafter. After a series of examinations, paraganglioma was diagnosed and excision of the tumor was performed. After surgery, blood pressure stabilized and her cardiac function had fully recovered at 4 months' follow-up.

Child↗

PubMed2001

Lipid myopathy associated with renal tubular acidosis and spastic diplegia in two brothers.

Lipid myopathy is a group of disorders involving mitochondrial fatty acid oxidation. We describe two brothers, 3 years 8 months old and 2 years 9 months old, respectively, with progressive spastic diplegia, developmental delay, failure to thrive, and chronic metabolic acidosis who had lipid myopathy and renal tubular acidosis. Brain magnetic resonance imaging revealed demyelinating changes in the periventricular white matter, which was compatible with spastic diplegia. These symptoms may be related to errors in fatty acid metabolism. Cerebral palsy had been misdiagnosed in both of these patients at another hospital. Therefore, for patients with late-onset and progressive spastic diplegia, detailed investigations for underlying diseases are warranted.

Acidosis, Renal Tubular↗

PubMed2000

Mitochondrial cytopathy combined with Fanconi's syndrome.

Severe muscle weakness in Fanconi's syndrome is rarely the result of mitochondrial cytopathy. We describe a rare case of a 9-year-old male with early onset of Fanconi's syndrome. He developed severe proximal muscle weakness exacerbated by hypokalemia and hypophosphatemia in childhood. The muscle biopsy revealed increased accumulation of abnormal mitochondria and fat droplets in histochemical stains and electron microscopy. Mitochondrial cytopathy cannot be excluded in Fanconi's syndrome with late onset of muscular impairment. Long-term follow-up of his clinical course is suggested to understand the natural history of this unusual case.

Acidosis, Renal Tubular↗

PubMed2000

Epidermal nevus syndrome with hypermelanosis and chronic hyponatremia.

Epidermal nevus syndrome is seldom encountered, and its association with hypermelanosis and the chronic syndrome of inappropriate antidiuretic hormone secretion (SIADH) has never been reported. A male neonate who developed intractable seizures and hyponatremia soon after birth is reported. He had alopecic patches on the scalp at birth. Large areas of skin hyperpigmentation, and epidermal nevi developed gradually. The clinical picture of hypotonic hyponatremia, high urine osmolality, elevated urine sodium, and euvolemia was compatible with SIADH. The seizures did not correlate with the hyponatremia, and no other cause for the seizures could be identified. The hyponatremia became chronic and was treated with a direct supply of sodium chloride. The development of the patient was markedly delayed at the last visit when he was 1 year of age. It is suggested that hypermelanosis and chronic SIADH may also be a variant presentation of epidermal nevus syndrome.

Brain↗

PubMed2000

Nephrotic syndrome in a bone marrow transplant recipient without chronic graft-versus-host disease.

A 5-year-old girl developed severe proteinuria and microscopic hematuria 17 months after allogeneic bone marrow transplantation (BMT) for chronic myeloid leukemia. These nephrotic symptoms occurred during cyclosporin tapering, in the absence of other signs of chronic graft-versus-host disease (GVHD). A renal biopsy revealed focal segmental glomerulosclerosis. After methylprednisolone therapy, the proteinuria gradually decreased. The altered or disordered immune regulation that occurred after BMT may have resulted in the development of nephrotic syndrome.

Bone Marrow Transplantation↗

PubMed2000

Renal malformations in children with Turner's syndrome.

Between 1988 and 1999, renal sonography and intravenous urography were performed to detect renal malformations in 54 patients with Turner's syndrome (TS). The mean age of these patients at diagnosis of TS was 9.2 +/- 4.6 years. Renal malformations were detected in 21 patients by intravenous urography and there was no significant difference in the frequency of renal malformations among different karyotype groups. Horseshoe kidney was the most common renal malformation, followed by duplex kidney. Fifteen of 21 renal malformations were not detected by renal sonography. We conclude that these TS patients had a high frequency of renal malformations, and that the detection rate of horseshoe kidney and duplex kidney by renal sonography was not satisfactory. Although renal sonography alone can be used to detect more severe renal malformations that may need further management, it may underestimate the frequency of renal malformation in children with TS.

Adolescent↗

PubMed1998

Correlation between urinary epidermal growth factor excretion and serum thyroid hormone in premature and term neonates.

Eighty neonates, including 14 full-term, 31 premature, 27 twin or triplet, 6 small-for-gestational-age, and 2 infants with hyperthyroidism, were evaluated. The urinary epidermal growth factor/creatinine ratio (EGF/Cr) on the 1st postnatal day was not statistically different among full-term, premature, multiple-pregnancy, and small-for-gestational-age infants (F = 1.06, p = 0.6). There was no difference in urinary EGF/Cr between the 1st postnatal day and the 7th day (p = 0.4 by paired t test). The urinary EGF/Cr was not correlated with the serum thyroid-stimulating hormone level (r = -0.162, n = 60, p = 0.21), but showed a positive correlation with serum total T3 (r = 0.526, n = 60, p < 0.001) and with serum total T4 (r = 0.460, n = 60, p < 0.001). The correlation between urinary EGF/Cr and serum free T4 was even much better (r = 0.727, n = 25, p < 0.001). These results implicate that thyroid hormone may play a role in regulating urinary EGF excretion.

Creatinine↗

PubMed1998

Urinary endothelin-1 in children with acute renal failure of tubular origin.

To understand the changes of urinary endothelin-1 (ET-1) concentrations in acute renal failure (ARF) and to investigate the origin of human urinary ET-1, we studied urinary ET-1 excretion in 70 normal children and 12 children with ARF caused by tubular dysfunction. Urinary ET-1 excretion was expressed as a ratio of urinary ET-1 to urinary creatinine (ET-1/Cr). Among healthy children, the highest urinary ET-1/Cr values were found during infancy. In patients with ARF, there was a positive correlation between urinary ET-1/Cr values and daily total urinary ET-1 (r = 0.42, n = 26, p < 0.05). Plasma ET-1 concentrations were elevated in children with ARF during the period of peak serum creatinine concentration. During the course of ARF, the lowest urinary ET-1/Cr value occurred during the period of peak serum creatinine, whereas the plasma ET-1 concentration declined after the peak. These results provide insight into the developmental changes of urinary ET-1 values in normal children, and illustrate the pattern of changes in plasma and urinary ET-1 concentrations during the course of ARF in children. The results suggest that renal production, rather than clearance from the circulation by glomerular filtration, may be the source of urinary ET-1.

Acute Kidney Injury↗

PubMed1997

Nephromegaly and elevated hepatocyte growth factor in children with biliary atresia.

Nephromegaly, a rarely mentioned but probably common situation, was studied in children with biliary atresia. We evaluated the length and the cross-sectional diameters of the kidney by ultrasound in 21 children with biliary atresia as well as in 50 healthy children. The ages ranged from 1 month to 10 years. Plasma hepatocyte growth factor (HGF) was measured in 18 children with biliary atresia and also in 18 age- and sex-matched normal controls. There was a significant nephromegaly (increase in the renal length and the kidney volume) in children with biliary atresia as compared with normal children (P < 0.001 by analysis of covariance). Plasma HGF levels were elevated in these patients (2.13 +/- 1.06 v 0.76 +/- 0.19 ng/mL in controls, P < 0.001) and had a positive correlation with the renal size after considering the effect of body height by multiple regression analysis (P = 0.0022 for renal length, and P < 0.001 for kidney volume). These results confirm the presence of large kidneys in biliary atresia and implicate the possible pathogenic role of HGF in such a condition. Nephromegaly in biliary atresia may provide a new in vivo model to study the mechanism of renal growth.

Biliary Atresia↗

PubMed1996

Urinary N-acetyl-beta-D-glucosaminidase activity in children with insulin-dependent diabetes mellitus.

Urinary N-acetyl-beta-D-glucosaminidase (NAG) is a sensitive indicator of renal tubular injury. The aim of the study is to determine the status of urinary NAG excretion in Chinese children with insulin-dependent diabetes mellitus (IDDM) but without any clinical evidence of nephropathy, and to try to find the possible associated factors of such tubular injury if any. Thirty-one children (8 males and 23 females) with IDDM who have normal serum creatinine, 24-hour urinary creatinine clearance and urinary total protein excretion were enrolled in the study. The mean age of the patients was 11.6 +/- 3.7 years. The random urinary NAG levels of the patients and the normal controls were 10.76 +/- 6.32 and 3.65 +/- 1.84 U/g Cr, respectively (p < 0.001). The diabetic patients were divided into 4 groups according to their duration of disease ( < 3, 3-5, 5-10 and 10-16 years). The random urinary NAG level of each group was significantly higher than that of the control group, but there was no statistically significant difference among any 2 of these 4 groups. No good correlation was noted in our study between urinary NAG and patients' age (r = -0.23, p = 0.21), serum cholesterol (r = 0.04, p = 0.84), insulin dosage (r = 0.13, p = 0.49), 24 hour urinary creatinine clearance (r= -0.41, p - 0.085) or urinary total protein excretion (r = -0.28, p = 0.26). However, the plasma HbAlc level correlated significantly with urinary NAG (r = 0.50, p < 0.01). We concluded that urinary NAG is increased in Chinese IDDM children without any clinical evidence of nephropathy. Such increased excretion is correlated with the plasma HbAlc level. Our results suggests that there is tubular dysfunction in the early stage of IDDM children even before there is any clinical evidence of nephropathy, and urinary NAG may reflect glycemic control in such patients.

Acetylglucosaminidase↗

PubMed1996

Decreased urinary epidermal growth factor in children with acute renal failure: epidermal growth factor/creatinine ratio not a reliable parameter for urinary epidermal growth factor excretion.

To verify some animal experimental results in humans, we have studied urinary epidermal growth factor (EGF) excretion in normal children as well as children with acute renal failure (ARF). Urinary EGF excretion was expressed as a ratio of urinary EGF to urinary creatinine concentration (EGF/Cr) for random and 24-h urine, and a daily total urinary EGF for 24-h urine. The highest urinary EGF/Cr in children was found at 1 mo to 3 y of age. There was a highly significant correlation between random urine EGF/Cr and 24-h urine EGF/Cr (r = 0.92, p < 0.001), whereas no correlation of urinary EGF/Cr with daily total urine EGF was found. During the course of ARF, a decline in urinary EGF/Cr from the period before peak serum creatinine to the period after the declination of serum creatinine was noted (p = 0.013, n = 13, by repeated measure analysis), with a constant low daily total urine EGF (p value not significant). However, a rise in both urinary EGF/Cr and daily total urine EGF was found between the period of serum creatinine decline and the period of completely normal serum creatinine (p < 0.001). Serum EGF remained unchanged throughout the course of ARF. These results suggest 1) the possible role of EGF in renal growth or maturation during the first 2 or 3 y of life, 2) the possible renal origin of human urinary EGF, and 3) decreased urinary EGF excretion in children with ARF. In particular, EGF/Cr is not a reliable indicator for the expression of actual urinary EGF excretion in ARF. Instead of urinary EGF/Cr, urinary EGF concentration may be used to predict the daily total urinary EGF excretion during ARF. These results provide the pattern of urinary EGF excretion during ARF in children and may be of help for further clinical studies.

Acute Kidney Injury↗

PubMed1994

Congenital nephrotic syndrome with microcephaly: report of a case.

Congenital nephrotic syndrome is an uncommon disease with variable etiology, course and prognosis; its association with microcephaly is even more unusual. A case is reported here of congenital nephrotic syndrome because of focal glomerulosclerosis in a three-month-old female infant with microcephaly since birth. There were no known renal diseases nor hereditary disorders in her family. The serologic tests for syphilis, toxoplasmosis, rubella, and cytomegalovirus infections were negative. Magnetic resonance imaging of the brain showed diffuse atrophic change of the cerebral hemispheres and brain stem with a remarkable increase of extracerebral space. The infant died at the age of four months without any clinical cause other than congenital nephrotic syndrome. These findings, including congenital nephrotic syndrome and microcephaly accompanied by various other clinical symptoms, have been described as a clinical entity with an autosomal recessive mode of inheritance.

Atrophy↗

PubMed1993

Renal calcification in very low birth weight infants.

Between January 1990 and December 1991, serial real-time ultrasound examinations and analyses of urine were performed on a total of 50 infants with birth weights less than 1,500 g to assess the incidence of renal calcification. Five infants (10%) developed renal calcification at a mean age of 48.8 +/- 14.1 days. These 5 infants with renal calcification had significantly shorter gestations (28.2 +/- 0.8 vs. 30.1 +/- 1.7 weeks, p < 0.0005) and lower birth weights (934 +/- 45 vs. 1,311 +/- 188 g, p < 0.0005) when compared with infants without renal calcification. None of the affected infants were treated with furosemide. Affected infants had a mean urine volume of 85.8 +/- 11.3 ml/kg/24 h, mean urine calcium level of 5.07 +/- 1.18 mg/kg/24 h, mean urine calcium to creatinine (mg/mg) ratio of 0.67 +/- 0.09, and a mean urine N-acetyl-beta-D-glucosaminidase (NAG) to creatinine (U/g) ratio of 259 +/- 133. Urinalyses showed that affected infants had significantly higher urine pH values and hematuria. Alkaline phosphatase concentrations and initial parathyroid hormone levels were not different among the two groups. In summary, renal calcification occurred in 10% of very low birth weight infants and multiple risk factors seem to be contributory. The smaller, sicker and more immature infants appear to have increased risk for developing renal calcification.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcinosis↗

PubMed1993

Renal function in neonatal hyperbilirubinemia.

A total of 75 jaundiced infants with gestational ages ranging from 37 to 42 weeks were studied during the first 10 days of age to evaluate renal function by measuring endogenous creatinine clearance (Ccr), fractional excretion of N-acetyl-beta-D-glucosaminidase (NAG) to creatinine, fractional excretion of sodium (FENa) and urine osmolality. All jaundiced infants were divided into two groups. Group 1 infants (n = 35) had total serum bilirubin levels ranging between 21 and 39.6 mg/dl (mean 27.2). Exchange transfusions were performed in all group 1 infants at the time of the initial study. Group 2 infants (n = 40), whose total serum bilirubin levels ranged between 12.3 and 20 mg/dl (mean 16.4), received phototherapy, except for 2. Conjugated bilirubin levels were less than 1.0 mg/dl in all these infants. Results were compared with 25 untreated control infants with corresponding gestational and postnatal ages. Follow-up studies were done in 27 of the 35 group 1 infants and in 32 of the 40 group 2 infants prior to hospital discharge, when total serum bilirubin levels had decreased to less than 10 mg/dl. Ccr, fractional excretion of NAG to creatinine, FENa and urine osmolality of group 1 infants were statistically significantly different when compared to those of group 2 and the control infants. The measured parameters in the post-treatment follow-up study of group 1 infants returned to near-normal levels when total serum bilirubin levels became normal. However, no significant differences were seen between group 2 and the control infants in any of the measured parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosaminidase↗

PubMed1992

Familial nephrogenic diabetes insipidus: report of two families.

Familial nephrogenic diabetes insipidus is a hereditary disorder, generally transmitted by sex-linked recessive genes with varying degrees of penetrance in females. The onset of this disorder occurs in infancy, usually characterized by unexplained fever, recurrent dehydration and failure to thrive. If left unrecognized, recurrent hyperosmolality and hypernatremia will lead to retarded growth and neurologic sequelae. Intracranial hemorrhage, consciousness disturbance and even mortality may occur in cases of acute dehydration episodes. We report on two families with nephrogenic diabetes insipidus, whose various symptoms and signs were studied to establish an accurate diagnosis. In pediatric practices, it is very important to recognize early those infants with obscure symptoms in order to preserve their psychomotor development and growth potential.

Adolescent↗

PubMed1991

Autosomal dominant polycystic kidney disease: an unusual presentation as unilateral renal mass in the infant.

The onset of autosomal dominant polycystic kidney disease in infants and children is unusual, and renal involvement is typically bilateral. The presentation of a unilateral renal mass in such a disorder is extremely rare. We report a 2-month-old infant with autosomal dominant polycystic kidney disease presenting with unilateral renal involvement; the literature concerning this entity is reviewed.

Female↗

PubMed1991

Complications of nephrotic syndrome in children.

One hundred and ninety-three nephrotic children with a total of 271 admissions during the past decade, from 1980 to 1989, were retrospectively reviewed for acute complications and unusual features of nephrotic syndrome. One hundred and forty-nine patients were male, 44 female. Hypertension was found in 41 children (21.2%). Nine patients (4.7%) had a total of 11 episodes of hypovolemic shock. These shock patients had a more severe hemoconcentration (mean hemoglobin concentration 19.6 +/- 1.5 g/dl) and hyponatremia (mean serum sodium 127.5 +/- 8.5 mmole/L). Bacterial infections occurred in 28 children (14.5%) with primary peritonitis in 13, sepsis in 6, cellulitis in 4, urinary tract infection in 4 and osteomyelitis in 1. Almost all infections were caused by gram-negative bacilli. Other complications or features included tetany in 4 (2.1%), thromboembolism in 2 (1.0%), pancreatitis in one (0.5%) and Fanconi syndrome in one (0.5%).

Bacterial Infections↗