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Biomedical subjects

Y Tomino

Publications and source records attributed to Y Tomino.

At least 19 recordsLinked to original sources
PubMed1995

Effect of a specific endothelin A receptor antagonist on murine lupus nephritis.

The present study was designed to assess whether a specific endothelin A (ETA) receptor antagonist, FR139317, affects the progression of lupus nephritis and affects transcription of mRNA for extracellular matrix (ECM) components, metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP)-1, and accumulation of ECM proteins in the renal cortex of NZB/W F1 mice. mRNA levels for alpha 1(I), alpha 1(III), alpha 1(IV) collagen chains, laminin B1 and B2 chains, heparan sulfate proteoglycan (HSPG), MMP-1, -2, -3, and TIMP-1 increased significantly as nephritis progressed in NZB/W F1 mice. At 48 weeks of age, the levels of mRNA for alpha 1(I), alpha 1(III), alpha 1(IV) collagen chains, laminin B1 and B2 chains, HSPG, MMP-1, -2, -3, and TIMP-1 were increased by 5.6- (P < 0.001), 3.6- (P < 0.01), 6.8- (P < 0.001), 5.2- (P < 0.001), 5.0- (P < 0.001), 6.0- (P < 0.001), 7.6- (P < 0.001), 4.2- (P < 0.01), 8.2- (P < 0.001), and 15.2-fold (P < 0.001), respectively, in the renal cortex of NZB/W F1 mice compared to NZW mice. Immunofluorescence microscopy showed that the accumulation of collagens I, III, and IV, laminin, and HSPG in the renal cortex of NZB/W F1 mice increased markedly with the progression of nephritis. At 20 weeks of age, NZB/W F1 and NZW mice were divided into two groups that received either FR139317 or its vehicle (saline) intraperitoneally, daily, for 28 weeks. The development of histological lesions, proteinuria, hypertension, accumulation of collagens I, III, and IV, laminin, and HSPG in the renal cortex of NZB/W F1 mice were suppressed by FR139317 treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Effects of a low-protein diet on glomerular endothelin family gene expression in experimental focal glomerular sclerosis.

1. The present study was designed to assess whether glomerular expression of mRNAs for endothelin-1 and endothelin-3, as well as endothelin receptors A and B is affected by a low-protein diet during the course of focal glomerular sclerosis. 2. Focal glomerular sclerosis was induced in rats by injection of puromycin aminonucleoside on days 0, 27, 34 and 41 in conjunction with unilateral nephrectomy on day 22. Control rats were subjected to nephrectomy or sham operation on day 22. 3. Animals were divided into six groups. In group 1, the puromycin aminonucleoside-injected rats were fed a standard diet containing 22% protein. In group 2, the puromycin aminonucleoside-injected rats were fed a low-protein diet containing 6% protein, which was initiated on the day of the first puromycin aminonucleoside injection. In group 3, the nephrectomized rats without puromycin aminonucleoside were fed a standard diet. In group 4, the nephrectomized rats without puromycin aminonucleoside were fed a low-protein diet. In group 5, the sham-operated rats were fed a standard diet. In group 6, the sham-operated rats were fed a low-protein diet. 4. The percentage of sclerotic glomeruli in group 1 rats increased markedly with time, reaching 77% on day 80. 5. The glomerular mRNA levels for endothelin-1 and endothelin receptors A and B increased significantly as glomerular sclerosis progressed, whereas no endothelin-3 mRNA was detected in the glomeruli of any group. The endothelin-1 production in isolated glomeruli from group 1 increased significantly as glomerular sclerosis progressed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Glomerular expression of smooth-muscle myosin heavy-chain isoforms in aminonucleoside nephrosis in rats.

1. We investigated the glomerular expression of three types of myosin heavy-chain isoforms, including S-myosin heavy-chain 40 (SM1), S-myosin heavy-chain 29 (SM2) and FS-myosin heavy-chain 34 (SMemb) in puromycin aminonucleoside nephrosis. 2. There was little change in SM1 and SM2 mRNA levels throughout the experiment. In contrast, glomerular SMemb mRNA increased on days 2 and 4 (before and soon after the onset of proteinuria, respectively), but declined on day 8 (the peak of proteinuria). 3. Histological myosin heavy-chain expression was examined using three antibodies against SM1, SM2 and SMemb. Immunohistochemically, SM1 and SM2 were absent in the glomeruli associated with puromycin aminonucleoside nephrosis until day 20. The SMemb isoform was barely detectable in normal glomeruli, but substantial amounts of SMemb were demonstrated in the glomeruli of rats with puromycin aminonucleoside nephrosis. In the puromycin aminonucleoside-treated rats, the number of SMemb-positive glomerular cells increased on days 2 and 4. 4. We examined whether levels of alpha-smooth-muscle actin or proliferating cell nuclear antigen correlated with myosin heavy-chain levels in the glomeruli of rats with puromycin aminonucleoside nephrosis. None of the cellular components in the glomeruli was positive for either alpha-smooth-muscle actin or proliferating cell nuclear antigen in puromycin aminonucleoside nephrosis. 5. Administration of methylprednisolone to puromycin aminonucleoside-treated rats resulted in the rapid disappearance of proteinuria. However, methylprednisolone did not affect SMemb mRNA or immunostaining in a glomeruli of rats with puromycin aminonucleoside nephrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Binding capacity of serum IgA to jacalin in patients with IgA nephropathy using jacalin-coated microplates.

Binding capacity of serum IgA to jacalin in 22 patients with IgA nephropathy, 14 patients with diffuse mesangial proliferative glomerulonephritis (non-IgA nephropathy) and 20 age-matched healthy adults was examined by enzyme-linked immunoassay (ELISA) using jacalin-coated microplates. In contrast to previous findings, the binding capacity of serum IgA to jacalin in patients with IgA nephropathy measured by ELISA using jacalin-coated microplates was significantly higher than that in healthy adults. The ratio of serum IgA levels measured by this method to those obtained by single radial immunodiffusion was significantly increased in patients with IgA nephropathy. It appeared that the capacity of serum IgA binding to jacalin was marked in these patients. It is concluded that the binding capacity of serum IgA to jacalin is not ubiquitously impaired in all patients with IgA nephropathy.

Adult↗
PubMed1995

Enalapril attenuates increased gene expression of extracellular matrix components in diabetic rats.

This study was designed to assess whether the glomerular expression of mRNA for extracellular matrix (ECM) components including alpha 1 (I), alpha 1 (III), and alpha 1 (IV) collagen chains, laminin B1 and B2 chains, metalloproteinases (MMP), and tissue inhibitor of metalloproteinases (TIMP) is affected by enalapril in 12- and 24-wk-old rat after streptozotocin injection. Animals were divided into three groups; untreated diabetic rats, enalapril-treated diabetic rats, and control rats. Enalapril treatment was continued for 24 wk. Enalapril reduced both creatinine clearance (P < 0.01) and urinary protein excretion (P < 0.01) in diabetic rats. In diabetic rats, mRNA levels for alpha 1 (IV) collagen chain, laminin B1 and B2 chains, and alpha 1(I) and alpha 1(III) collagen chains increased significantly at 24 wk compared with those in controls [alpha 1(IV): 3.8-fold (P < 0.01); laminin B1: 6.2-fold (P < 0.01); laminin B2:5.4-fold (P < 0.01), alpha 1(i): 4.8-fold (P < 0.01) and alpha 1(III): 3.8-fold (P < 0.01)]. At 24 wk, mRNA levels for MMP-1 and MMP-3 fell to 40% (P < 0.01) and 20% (P < 0.01), respectively, in the glomeruli of diabetic rats compared with levels in controls. In contrast, mRNA levels for TIMP-1 and TIMP-2 increased significantly at 24 wk after streptozotocin injection (TIMP-1: 8.0-fold (P < 0.01) and TIMP-2: 6.4-fold (P < 0.01)).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Modulation of glomerular endothelin and endothelin receptor gene expression in aminonucleoside-induced nephrosis.

This study assessed glomerular endothelin (ET)-1, ET-3, and ET-receptor A and B mRNA levels in puromycin aminonucleoside (PAN)-induced nephrosis. During the nephrotic stage, 8 days after PAN injection, ET-1 and ETB receptor mRNA were elevated by 2.8 +/- 0.8-fold (P < 0.01) and 2.4 +/- 0.9-fold (P < 0.01), respectively, as compared with controls. These mRNA levels decreased to control levels by Day 20, when the nephrosis was in remission. In contrast, glomerular ETA receptor mRNA levels did not change in PAN nephrosis or control rats during the experimental period. ET-3 mRNA was not detected in the glomeruli of PAN nephrosis or control rats. Additionally, plasma ET concentration and glomerular ET production were measured in PAN nephrosis and control rats by radio-immunoassay. Eight days after PAN injection, ET-1 levels in plasma and glomeruli were not significantly altered in rats with PAN-induced nephrosis (glomeruli, 104.68 +/- 16.46 pg/mg of protein versus 98.24 +/- 13.68 pg/mg of protein; plasma, 2.68 +/- 1.10 versus 2.52 +/- 0.98 pg/mL). The administration of methylprednisolone to PAN rats resulted in the rapid disappearance of proteinuria and partially attenuated the increased ET-1 and ETB receptor gene expression in the glomeruli. These data indicate that glomerular ET-1 and ETB receptor expression in PAN nephrosis in increased at the mRNA level and that methylprednisolone treatment results in an attenuated increase.

Animals↗
PubMed1995

Effect of a specific endothelin receptor A antagonist on mRNA levels for extracellular matrix components and growth factors in diabetic glomeruli.

We have previously reported that the mRNA levels of extracellular matrix (ECM) components including alpha 1(I), alpha 1(III), and alpha 1(IV) collagen chains, laminin B1 and B2 chains, and growth factors including tumor necrosis factor (TNF)-alpha, platelet-derived growth factor (PDGF)-B chain, transforming growth factor (TGF)-beta, and basic fibroblast growth factor (FGF) all increase with age in diabetic glomeruli. The present study was designed to assess whether glomerular expression of these mRNAs in rat diabetic glomeruli is affected by a specific endothelin receptor A antagonist, FR139317. Diabetes was produced by streptozotocin injection, and animals were divided into four groups: untreated diabetic rats, FR139317-treated diabetic rats, control nondiabetic rats, and FR139317-treated control rats. FR139317 treatment was continued for 24 weeks. FR139317 attenuated the rise in creatinine clearance (P < 0.01) and reduced urinary protein excretion (P < 0.01) in diabetic rats, but did not affect blood pressure. FR139317 attenuated the increases in glomerular mRNA levels of alpha 1(I) (P < 0.01), alpha 1(III) (P < 0.01), and alpha 1(IV) (P < 0.01) collagen chains, laminin B1 (P < 0.01) and B2 (P < 0.01) chains, TNF-alpha (P < 0.01), PDGF-B (P < 0.01), TGF-beta (P < 0.001) and basic FGF (P < 0.01) in diabetic rats. However, FR139317 did not affect these mRNA levels in glomeruli of control rats. These findings suggest that FR139317 may be useful in the treatment of diabetic glomerulopathy by reducing mRNA levels of ECM components and growth factors.

Aging↗
PubMed1995

[Symptoms in patients with tubulo-interstitial nephritis].

High dosages of nephrotoxic drugs in elderly patients might be correlated with an increase in the number of patients with tubulo-interstitial nephritis (TIN). In patients with acute TIN, marked fever, back or flank pain, CVA tenderness, skin rash, arthralgia, eosinophilia, and eosinouria are observed. Clinical symptoms might be induced by glomerular, proximal tubular or distal tubular dysfunction in chronic TIN. Mild to moderate proteinuria, edema, hypertension, azotemia, glucosuria, aminoaciduria, polyuria and polydipsia are characteristic findings in patients with chronic TIN. These findings are slowly progressive in such patients. It appears that the marked fibrosis with lymphocyte infiltration in the interstitium is a poor clinical marker in patients with TIN. Furthermore, it is important to differentiate TIN from glomerulonephritis.

Diagnosis, Differential↗
PubMed1994

Detection of glycosylated protein in renal tissues and dermal vascular vessels in the microalbuminuric stage of diabetic nephropathy using the nitro blue tetrazolium reaction.

Detection of glycosylated protein in renal and dermal tissues was performed in patients in the microalbuminuric stage of diabetic nephropathy using the nitro blue tetrazolium (NBT) reaction. The intensity of NBT staining in glomeruli and dermal vascular vessels was marked in the microalbuminuric stage as well as in the overtly proteinuric stage. The NBT staining in the renal and dermal vascular walls in both stages was significantly stronger than in the samples of control autopsy patients. It appeared that nonenzymatic glycosylation in various tissues, i.e. kidneys and dermal vascular vessels, had already progressed in the microalbuminuric stage in patients with diabetic nephropathy.

Adult↗
PubMed1993

Detection of activated platelets in urinary sediments by immunofluorescence using monoclonal antibody to human platelet GMP-140 in patients with IgA nephropathy.

The presence of activated platelets in the urinary sediments was studied by indirect immunofluorescence using monoclonal antigranular membrane protein (GMP)-140 antibody. GMP-140 is generally expressed on the activated-platelets and -vascular endothelial cells. The purpose of the present study was to determine if the presence of activated platelets in the urinary sediments is correlated with glomerular injuries in patients with IgA nephropathy. Fourteen patients with IgA nephropathy and 11 patients with diffuse mesangial proliferative glomerulonephritis without glomerular IgA deposition (PGN) were examined. The number of activated platelets in the urinary sediments was markedly increased in patients in the advanced stage of IgA nephropathy. The ratio of activated platelets to total platelets in the urinary sediments was also increased in such patients. It appears that the detection of activated platelets in the urinary sediments is useful in determining the degree of histological changes in IgA nephropathy.

Adult↗
PubMed1992

Oxidative metabolism of polymorphonuclear leukocytes (PMN) in patients with IgA nephropathy.

The production of hydrogen peroxide (H2O2) by neutrophilic polymorphonuclear leukocytes (PMN) after stimulation and the infiltration of PMN in glomeruli were determined in 20 patients with primary IgA nephropathy. The H2O2 production of PMN after the stimulation was measured with a spectrophotometer using horseradish peroxidase as substrate. The results were as follows: 1) when PMN were pretreated with cytochalasin B, H2O2 production after stimulation with heat-aggregated IgG (IgG) or serum-treated zymosan (STZ) was significantly higher in patients with IgA nephropathy than in controls, and 2) there was an increased amount of PMN localized in glomeruli in patients with IgA nephropathy using immunofluorescence of monoclonal anti-PMN antibody. It appeared that the increased renal infiltration of PMN which have a high potential for production of reactive oxygen species might induce the glomerular injuries in patients with IgA nephropathy.

Adult↗
PubMed1992

Renal platelet-derived growth factor gene expression in NZB/W F1 mice with lupus and ddY mice with IgA nephropathy.

The present study was carried out to determine how platelet-derived growth factor (PDGF)-A and -B chain mRNA expression correlate with disease activity in the renal cortex of NZB/W F1 mice, a model of systemic lupus erythematosus, and ddY mice, a model of IgA nephropathy. The PDGF-A and -B chain mRNA levels increased significantly as nephritis progressed in NZB/W F1 mice. In the renal cortex of ddY mice, however, the PDGF mRNA levels increased slightly with age. The PDGF mRNA levels in ddY mice were lower than those in NZB/W F1 mice. In the NZW control kidneys, the PDGF mRNA levels changed minimally throughout the experiments. A positive correlation was noted between PDGF mRNA levels and histopathological changes in renal tissues. At the onset of nephritis, NZB/W F1 mice were divided into two groups that received either methylprednisolone (MPSL) or saline injections for 5 months. The development of histopathological lesions and the increased PDGF mRNA levels were suppressed by MPSL treatment. These data suggest that PDGF plays a role in the progression of nephritis and that the beneficial effect of MPSL correlates with its ability to decrease the abnormally high PDGF mRNA levels seen in lupus nephritis.

Animals↗
PubMed1992

Glomerular alterations in children with biliary atresia.

To investigate the association of glomerular involvement with biliary atresia, we carried out the following studies: (1) review of the clinical records of 120 patients, (2) histologic study of the kidneys obtained at autopsy from 28 patients, and (3) measurements of circulating immune complexes. Of 90 patients with adequate follow-up information, 40 (44.4%) had hematuria, proteinuria, or both. All the kidney specimens showed a wide variety of mesangial proliferation, and immunoglobulins were present in 23 of 26 cases. There was a good correlation between the glomerular alterations and the period of reduced hepatic function. When IgA was present in the mesangium, IgA2 and secretory components were detected. Elevated serum IgA and circulating IgA-containing immune complex levels were found in patients with prolonged obstructive jaundice. These findings indicate that glomerular alterations may occur subsequently in patients with biliary atresia, and that IgA of intestinal mucosal origin plays some role in the development of these lesions.

Antigen-Antibody Complex↗
PubMed1992

Possible mechanism of impaired calcium and vitamin D metabolism in nephrotic rats.

Patients who have nephrotic syndrome and normal renal function are hypocalcemic in spite of the elevated levels of serum parathyroid hormone (PTH) caused by a low serum concentration of 1,25-dihydroxyvitamin D[1,25(OH)2D], presumably because of its loss in urine. However, it has not been established whether the conversion of 25-hydroxyvitamin D[25(OH)D] into 1,25(OH)2D is impaired in the kidney. In this study, we examined the serum levels of vitamin D metabolites, and kinetics of renal 25(OH)D-1-hydroxylase activity in vitro, and nephrogenous cyclic AMP excretion in response to exogenous PTH administration in puromycin aminonucleoside-induced nephrosis in rats. Plasma ionized calcium and the serum levels of vitamin D metabolites were lower, and conversely, the serum PTH level was higher, in nephrotic rats than in controls. Serum 1,25(OH)2D levels were higher in 25(OH)D3-treated nephrotic rats than in untreated nephrotic rats, indicating that the low 1,25(OH)2D level in nephrotic rats is partially due to the low concentration of 25(OH)D. Although PTH levels were higher in nephrotic rats than in control rats, the Vmax of renal 25(OH)D-1-hydroxylase and nephrogenous adenosine 3',5'-monophosphate (cyclic AMP) excretion in response to exogenous PTH were significantly lower in nephrotic animals than in controls. These results suggest that abnormalities in calcium and vitamin D metabolism in nephrotic rats are partially attributable to impaired proximal tubular function.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed1992

Perforin gene expression in T lymphocytes correlates with disease activity in immunoglobulin A nephropathy.

1. We studied perforin gene expression in T lymphocytes obtained from 26 patients with IgA nephropathy and from 15 healthy age-matched control subjects. 2. The majority of patients with IgA nephropathy (96%) had elevated perforin mRNA expression, whereas no perforin mRNA expression was detected in the T lymphocytes of normal control subjects. 3. A positive correlation was noted between perforin mRNA expression and urinary protein excretion. 4. Perforin mRNA expression correlated also with the histopathology in the renal tissue of patients with IgA nephropathy. 5. Sixty per cent of patients with grade III or IV histopathology had high perforin mRNA expression in T lymphocytes [more than (++)]. 6. These studies suggest that disregulation of perforin gene expression in T lymphocytes may be associated with the progression of IgA nephropathy and could be used as an indicator of disease activity.

Adolescent↗