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Biomedical subjects

Y Nakamoto

Publications and source records attributed to Y Nakamoto.

At least 91 records · Page 5Linked to original sources
PubMed1994

Sclerodermatous renal crisis in a patient with mixed connective tissue disease.

We report a patient with mixed connective tissue disease who developed accelerated hypertension, acute renal insufficiency, and microangiopathic hemolytic anemia. A renal biopsy specimen showed marked vascular changes in small arteries consisting of laminated endothelial cell proliferation and luminal thrombosis, which were similar to those of scleroderma renal crisis. This patient was successfully treated with an angiotensin-converting enzyme inhibitor as well as analogues of prostaglandin E1 and prostaglandin I2. In patients with mixed connective tissue disease, a fatal complication like scleroderma renal crisis should be considered when the blood pressure rapidly increases. The combined administration of angiotensin-converting enzyme inhibitors and analogues of prostaglandin E1 and prostaglandin I2 may be an effective treatment for this complication.

Acute Kidney Injury↗
PubMed1994

Successful delivery in a pregnant women with crescentic IgA nephropathy.

A 27-year-old Japanese female developed nephrotic syndrome and impaired renal function during pregnancy. A renal biopsy performed at 21 weeks of gestation revealed crescentic IgA nephropathy. She was treated with steroid pulse therapy followed by conventional steroid therapy. Although the nephrotic syndrome was persistent, the impaired renal function did not deteriorate after the treatment. A live infant was delivered by cesarean section at 37 weeks of gestation. After the delivery, both the nephrotic syndrome and renal insufficiency improved gradually. The indications for renal biopsy and treatments for active IgA nephropathy during pregnancy are discussed.

Adult↗
PubMed1994

Induction and altered localization of 90-kDa heat-shock protein in rat kidneys with cisplatin-induced acute renal failure.

We purified 90-kDa heat-shock protein (HSP90) from murine brains and produced a specific antibody against the protein in a rabbit. This antibody cross-reacted with rat renal HSP90 on immunoblot analysis. Using the antibody, we observed serial immunohistochemical localizations of HSP90 in rat kidneys with cisplatin-induced acute renal failure. In normal kidneys, HSP90 was mainly localized in the cytoplasm of distal tubules and collecting ducts. Twenty-four hours after the cisplatin exposure, a rapid expression of HSP90 was observed in the cytoplasm of epithelial cells in the Henle's loops (especially at the luminal side), although there was little change in these cells on light microscopy. Degenerative changes of epithelial cells appeared in the S3 segment of proximal tubules on day 3, and epithelial cell regeneration in this portion was found from day 5. On day 5, HSP90 was markedly expressed in both the cytoplasm and the nucleus of epithelial cells in the S3 segment with a granular pattern. The induced HSP90 was then accumulated in the cytoplasm of these cells on day 7 and disappeared on day 14. Immunoblot analysis of isotonic buffer-extractable renal fractions showed that there was a rapid induction of HSP90 from day 1, and that the maximum induction of HSP90 in the extract at day 5 was 6-fold that of a control. These results suggest that HSP90 plays some role related to functional abnormalities of the Henle's loops at the luminal side, and in the regeneration of damaged cells in the S3 segment of proximal tubules, during the course of cisplatin-induced acute tubular injury.

Acute Kidney Injury↗
PubMed1994

Inverse relationship between serum cholinesterase activity and the administration of cyclophosphamide: an index of cyclophosphamide therapy.

To determine whether serum cholinesterase activity can be a monitoring index of cyclophosphamide therapy in patients with steroid-resistant glomerulopathy, we compared the cholinesterase activity of 37 patients who received a combined therapy that included the use of cyclophosphamide, prednisolone, antiplatelet drugs, and anticoagulant drugs, with the cholinesterase activity of 25 patients who received prednisolone therapy that excluded cyclophosphamide from the combined therapy. In the prednisolone and the combined groups, cholinesterase activity declined as shown in the following formula: Y = 371-26.4 x log(X): (r2 = 0.28), Y = 444-147.7 x log(X): (r2 = 0.95), respectively. (Y: cholinesterase activity, X: the day after treatment). In the combined therapy group, the prevalence of adverse reactions following treatment in the subgroup below 200 U/l of cholinesterase activity was significantly greater (P < 0.01) than that in the subgroup above 200 U/l of cholinesterase activity. However, there was no significant difference (P < 0.25) in the prevalence of adverse reactions between the subgroups with more or less than 184 U/l of cholinesterase activity following treatment. These results suggest the importance of not going below 200 U/l of cholinesterase activity after treatment when the normal cholinesterase activity range is between 300 and 760 U/l (e.g. less than 65% of the lowest value of the normal range of other hospitals) in order to eliminate the hazards of cyclophosphamide to the patients with steroid-resistant glomerulopathy.

Adolescent↗
PubMed1993

Epileptic seizure of El mouse initiates at the parietal cortex: depth EEG observation in freely moving condition using buffer amplifier.

The initiation site of seizure discharges and the relationship between behavioral manifestations and electroencephalography were investigated in the El mouse, a hereditary epilepsy model. The chronic depth electrodes were implanted stereotaxically into the frontal cortex, parietal cortex, temporal cortex, hippocampus, striatum, amygdaloid complex, non-specific nuclei of thalamus and substantia nigra. Electrical activities were recorded in freely moving condition with use of the buffer amplifier devised in the laboratory and behaviors were monitored simultaneously. Seizure spike discharges started in the parietal cortex and spread out into other brain areas. When the hippocampus was involved, the tonic convulsion occurred behaviorally. The paper describes the first direct evidence of the initiation and propagation of seizure discharges in the brain of El mouse.

Amplifiers, Electronic↗
PubMed1993

Acute interstitial nephritis with symmetric enlargement of the lacrymal and salivary glands and systemic lymphadenopathy.

We describe a 40-year-old man who developed symmetric enlargement of the lacrymal and salivary glands and systemic lymphadenopathy. Laboratory findings included eosinophilia, polyclonal hypergammaglobulinemia, elevated circulating immune complexes, hypocomplementemia, and renal insufficiency. The lymph node pathology was atypical of angioimmunoblastic lymphadenopathy with disproteinemia (AILD), in that it lacked a prominence of arborizing small vessel proliferation. Despite extensive examinations, the cause of the atypical AILD process has not been identified. However, a flow-cytometric analysis of immunophenotypes of lymphoid cells from the lymph node revealed a predominance of activated helper/inducer T cells, indicating a hyperimmune state. Acute interstitial nephritis was secondary to the renal propagation of the atypical AILD process. Thus, atypical AILD can be a new cause of acute interstitial nephritis. A course of combined steroids and immunosuppressive treatment resolved those pathologic disorders for 5 years.

Acute Disease↗
PubMed1993

Kidney diseases among the elderly--a clinicopathological analysis of 247 elderly patients.

We describe the clinicopathological features of 247 patients over the age of 60 with renal disorders. We acceded the histological classification of WHO recommendation, except for IgA nephropathy as primary glomerulonephritis. All nephrotic patients other than those with diabetic glomerulosclerosis (DGS) or amyloidosis were treated with steroids and/or immunosuppressants. Clinical data showed 88 patients with nephrotic syndrome. The histological study revealed that 142 patients had primary renal diseases and 105 patients had secondary renal diseases. Of 88 nephrotic patients, 35 were membranous nephropathy (MN) and 9 were minimal change nephrotic syndrome (MCNS). In secondary nephrosis, amyloidosis and DGS were diagnosed in 9 and 7 patients, respectively. A good response to therapy was obtained in MN (89%) and MCNS (78%). However, nephrotic patients with mesangial proliferative glomerulonephritis, amyloidosis, or DGS had unfavorable outcomes. Histological observations are useful aids in estimating the prognosis and therapy selection for renal disorders even in elderly patients.

Age Factors↗
PubMed1993

Immune complex type crescentic glomerulonephritis accompanied with perinuclear anti-neutrophil cytoplasmic antibodies.

A 70-year-old male developed rapidly progressive glomerulonephritis syndrome with serum perinuclear anti-neutrophil cytoplasmic antibodies (P-ANCA). A renal biopsy showed diffuse crescentic glomerulonephritis. Immunofluorescence microscopy revealed 2+ granular staining of IgG over the mesangial area and along glomerular capillary walls. Electron microscopy showed scattered deposits in the paramesangial area. These morphologic findings were consistent with those of immune complex type crescentic glomerulonephritis (IC-CGN). Serum C3, C4, and CH50 were within normal limits, and circulating immune complexes were not detected by C1q-binding assay, but both P-ANCA and anti-myeloperoxidase antibodies were positive. A possible relation of P-ANCA to IC-CGN is discussed.

Aged↗
PubMed1993

Altered localization of 73-kilodalton heat-shock protein in rat kidneys with gentamicin-induced acute tubular injury.

BACKGROUND: The constitutive 73-kilodalton heat-shock protein (HSP73) has been shown to have various essential functions in cells under both normal and stress conditions. In the present study, we observed serial localizations of HSP73 in rat kidneys with gentamicin-induced acute tubular injury. EXPERIMENTAL DESIGN: Sprague-Dawley rats received gentamicin (80 mg/kg/day) for 14 days, and developed acute proximal tubular injury. The intrarenal immunohistochemical distribution of HSP73 was examined by using a specific antibody against HSP73. In addition, HSP73 content in both isotonic buffer- and detergent-extractable renal fractions were measured by immunoblot analysis. RESULTS: After the gentamicin exposure, HSP73 moved from the nucleus to the cytoplasm, and accumulated in granules that were considered to be expressed within enlarged lysosomes in the injured proximal tubular epithelial cells. These granules started to appear from 36 hours after the first gentamicin exposure, enlarged in size until day 12, and gradually diminished after day 18. At day 27, the HSP73 localization pattern returned to that in the normal kidney. Moreover, significantly increased HSP73 protein bands were detected by immunoblot of detergent-extractable fractions from gentamicin-treated rat kidneys at from 36 hours to day 15 after the gentamicin exposure. CONCLUSIONS: Our findings suggest that HSP73 is rapidly induced as an insoluble form in injured lysosomes of the proximal tubular epithelial cells during gentamicin-induced acute tubular injury.

Animals↗
PubMed1992

Significance of fibrils in the formation of the Kimmelstiel-Wilson nodule.

The pathogenesis of the nodular lesion in diabetic glomerulosclerosis is described in association with fibrils. Thirteen diabetic patients with glomerular nodular lesions and 9 diabetics without the nodules were examined by electron microscopy using periodic acid-thiocarbohydrazide-silver proteinate staining. In cases of nodular glomerulosclerosis, abundant fibrillar structures mixed with electron-dense material were detected within the nodule and the mesangial matrix. They were also occasionally observed along the subendothelial space of the glomerular capillary walls. On the cross-section, these fibrils, including the lucent periphery, were 34 nm wide. Immunohistologically, collagen V and collagen VI were detected in nodular lesions. In contrast, in cases of the diffuse type of glomerulosclerosis, the widened mesangium was composed of dense material, which resembled the original mesangial matrix. The above fibrils were not detected in the mesangium. These findings suggest that the accumulation of the peculiar fibrils in the glomerular mesangium is a major pathogenic factor in the formation of Kimmelstiel-Wilson nodules.

Adult↗
PubMed1992

Purification of a mature form of 60 kDa heat-shock protein (chaperonin homolog) from porcine kidney and its partial amino acid sequence.

1. We have purified a 58 kDa collagen-binding protein from a 4 M guanidine hydrochloride extract of porcine kidney. 2. This protein was identified as a mature form of 60 kDa heat-shock protein (HSP60, chaperonin homolog) based on its partial amino acid sequence. 3. Among 98 determined sequences of the porcine protein, 97 residues were identical with those deduced from nucleotide sequence of the cDNA encoding human HSP60.

Amino Acid Sequence↗
PubMed1992

Alcohol drinking and high blood pressure: data from a 1980 national cardiovascular survey of Japan.

Many epidemiological cross-sectional studies have confirmed that alcohol drinking is related to high blood pressure. However, the impact of alcohol drinking on high blood pressure in the general population including older people has only been reported on in a few studies. The association between alcohol drinking and blood pressure or the prevalence of hypertension was examined using cross-sectional data of 4795 men and 6102 women aged 30-94, randomly selected from the Japanese population in 1980. The response rates were 74 and 84% for men and women, respectively. The prevalence of hypertension adjusted for body mass index (BMI, kg/m2) was significantly higher in everyday male drinkers than in male non-drinkers from the youngest age group (30-39 years) to oldest age group (70 years and over). A relationship between alcohol and blood pressure was found only in the youngest age group (30-39 years) of female drinkers. In each 10-year age-group of men, the BMI-adjusted systolic and diastolic blood pressures in everyday drinkers were 7-10 and 4-6 mmHg higher than those in non-drinkers. The relationship between alcohol and blood pressure in men was confirmed by multiple regression analysis adjusting for age and BMI in both younger (30-59 years) and older (60-94 years) people. The impact of alcohol drinking on blood pressure in men should be taken into account in the primary prevention of blood pressure related diseases and in the treatment of hypertension in both younger and older people.

Adult↗
PubMed1992

Renal localization of the constitutive 73-kDa heat-shock protein in normal and PAN rats.

We purified the constitutive 73-kDa heat-shock protein (HSP73) from the bovine brain, and produced a specific antibody against the protein in a rabbit. On immunoblotting, the antibody cross reacted only with a protein band with a molecular mass of 73 kDa in a crude extract from normal rat kidneys, which was regarded as rat renal HSP73. The intrarenal immunohistochemical distribution of HSP73 was examined by using this antibody, on both normal rat kidneys and kidneys with puromycin aminonucleoside nephrosis. HSP73 was predominantly present in epithelial cells of the glomeruli and the tubules. In normal kidneys, HSP73 was generally localized in both the cytoplasm and the nucleus of these epithelial cells, except for proximal tubular epithelial cells. On the other hand, in kidneys with puromycin aminonucleoside nephrosis, HSP73 accumulated in the cytoplasm at a level higher than in the nucleus in association with the severity of renal dysfunction and proteinuria. These findings indicate that HSP73 is mainly expressed in glomerular and tubular epithelial cells in the kidney under a physiological condition, and that its expression changes from the nucleus to the cytoplasm under pathological conditions such as a protein overload to these epithelial cells.

Animals↗
PubMed1992

Localization of phosphoinositide-specific phospholipase C-alpha in porcine kidney.

The presence of multiple forms of phosphoinositide-specific phospholipase C (PLC), an important enzyme in the cell signal transduction, suggests that specialized functions of tissues and cells may require different modes of PLC regulation. In the present study, we have purified a 54-kDa heparin-binding protein from a 4 M guanidine hydrochloride extract of porcine kidney, and identified it as one of isoenzymes of PLC on the basis of its partial amino acid sequence. Among 194 determined sequences of the porcine protein, 186 residues were identical with those deduced from nucleotide sequence of the cDNA encoding rat PLC-alpha. The subcellular distribution of porcine renal PLC-alpha was examined by Western blotting by using a specific antibody against the purified protein. Quantitation of the Western blots revealed that 70% of PLC-alpha was membrane-associated. Immunohistochemical studies showed a specific localization of PLC-alpha in epithelial cells of distal tubules and collecting ducts of normal porcine kidney, but not in other cells composing the nephron. Moreover, the highest expression of PLC-alpha was observed in apical membranes in these epithelial cells. Thus, this form of PLC is considered to have a specific role in the signal transduction process related to regional renal tubular functions.

Amino Acid Sequence↗
PubMed1992

Case report: nephrotic syndrome associated with a total hydatidiform mole.

The authors describe a 51-year-old Japanese woman who developed nephrotic syndrome in association with a total hydatidiform mole. The nephrotic syndrome remitted completely following hysterectomy. A renal biopsy performed before the operation showed diffuse mesangial cell proliferation of a moderate degree, and thickened capillary walls with focal and segmental subendothelial deposits, as well as circumferential mesangial interposition. Occasional foci of the mesangiolysis were also observed. Immunofluorescence microscopy revealed granular staining of IgM along the glomerular capillary walls in a fringe pattern. A review of the literature revealed that this patient appears to be the first case of nephrotic syndrome associated with a total mole, although there have been two cases of nephrotic syndrome due to preeclamptic nephropathy associated with a partial or transitional mole.

Female↗
PubMed1992

Kappa light chain nodular glomerulosclerosis with conspicuous crescent formation and tubulointerstitial injury. Report of a case.

We describe a 39-year-old man who developed kappa light chain nodular glomerulosclerosis with superimposed conspicuous crescent formation and extensive tubulointerstitial injury. The clinical picture was characterized by nephrotic syndrome and rapidly progressive glomerulonephritis. Incessantly progressive loss of renal function culminated in irreversible renal failure 7 weeks after initial manifestations of renal insufficiency. The patient has since been maintained on thrice weekly hemodialysis with chemotherapy for five years. At the time of pathologic diagnosis by renal biopsy, there was no evidence of multiple myeloma, and no serum M-component or Bence-Jones proteinuria was detected. An initial bone marrow aspirate revealed the presence of 0.6% atypical lymphocytes as the sole abnormality, although these were later identified as atypical plasma cells. These cells had also infiltrated the renal interstitium. Crescentic kappa light chain nodular glomerulosclerosis lacking evidence of plasma cell dyscrasia should be included in the differential diagnosis of rapidly progressive glomerulonephritis.

Adult↗