Mahito Nakayama

Kumamoto University, Kumamoto, Kumamoto Prefecture, Japan

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Publications (17)40.22 Total impact

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    ABSTRACT: To know the possible involvement of reactive oxygen species and the site(s) of their action in puromycin aminonucleoside (PAN)-induced renal injury, two types of superoxide dismutase (SOD) derivatives were synthesized: one (SM-SOD) circulates bound to albumin with a half-life of 6 h and the other (AH-SOD) linked with hexamethylenediamines rapidly undergoes glomerular filtration and accumulates in renal proximal tubule cells without being excreted in urine. When injected intravenously to the rat, PAN induced a marked proteinuria, increased plasma levels of cholesterol and triglyceride, and suppressed the growth of animals. Intravenously administered SM-SOD significantly inhibited such changes induced by PAN. However, native SOD which rapidly undergoes urinary excretion failed to inhibit the renal injury caused by PAN. Though AH-SOD markedly accumulated in renal proximal tubule cells, it also failed to inhibit the renal injury. These results suggested that superoxide and/or its hazardous metabolite(s) in and around the renal glomerulus, but not in tubule cells, may play critical roles in the pathogenesis of PAN-induced renal injury.
    No preview · Article · Feb 1995 · Nephron
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    ABSTRACT: Two monoclonal antiboides (MAbs) against human renal glomeruli, HEP1 and HBM1, were produced using isolated human glomeruli as an antigen. Immunohistochemical and immunoelectron microscopic analyses revealed that the recognition site of HEP1 is the cell surface of the visceral glomerularepithelial cells. HEP1 showed no reaction in the renal interstitium or in other tissues. HBM1 recognized an antigen present in the basal lamina of the renal glomeruli, Bowman's capsule, and partly in the basement membrane of renal tubules, but it was not reactive with the mesangial matrix or renal interstitium. The isotype of both MAbs was IgG1, k. The molecular weights of their corresponding antigens were 127–177 and 220kD, respectively. Besides human tissues, HEP1 also showed cross-reactions with antigens in the visceral glomerular epithelial cells of various animals other than mice. HBM1 recognized human antigen only. Using both MAbs, eight cases of crescentic glomerulonephritis were examined immunohistochemically. As a result, it was demonstrated that the crescents may not be formed by visceral glomerular epithelial cells. From this study, these two MAbs appear to be userful markers for the evaluation of renal glomerular disorders.
    No preview · Article · Jan 1994 · The Journal of Pathology
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    ABSTRACT: The effect of blood access on platelets and clotting factors was investigated in 46 azotemic patients. Arteriovenous fistula was used in 10 patients (AVF group), and polyurethane double-lumen catheters were inserted through the subclavian vein in 6 patients (PUS group) or through the femoral vein in 15 patients (PUF group). Indwelling urokinase-immobilized single-lumen catheters and double-lumen catheters were placed in the femoral vein of 5 patients (UKS group) and 10 patients (UKD group), respectively. Blood cell counts, beta-thromboglobulin (beta-TG), platelet factor 4 (PF4), prothrombin time, and activated partial thromboplastin time were measured before insertion while catheters were indwelling and after catheters were pulled out. Although the platelet count decreased to 83% of the initial value during indwelling in the PUF group and 89% in the PUS group, it did not decrease in the AVF, UKS, and UKD groups. There were no differences between the PUF and PUS groups nor between the UKS and UKD groups. Plasma beta-TG increased in the PUF and UKD groups with indwelling catheters but did not change with the AVF. From these results, we conclude that the AVF did not activate platelets, the urokinase-immobilized catheter activated platelets, and the polyurethane catheter activated and decreased platelets. This might be due to the different surface properties of each blood access. Thus, the urokinase-immobilized catheter seems to be more favorable than the polyurethane catheter for emergency blood access.
    No preview · Article · Apr 1993 · Artificial Organs
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    ABSTRACT: The occurrence of rhabdomyolysis and acute renal failure associated with cytomegaloviral infection is rare. A 27-year-old housewife was admitted to our hospital with complaints of thirst, muscle weakness, abdominal pain and oliguria. There was no past history of diabetes, drinking, fever or drug habituation and a negative family history. Laboratory tests revealed myoglobinuria, hyper-pancreatic type amylaseuria, hyperglycemia, azotemia and highly increased creatine phosphokinase in the plasma. She was treated with hemodialysis and insulin therapy. Serological studies showed a 4-fold increase in cytomegalovirus antibody titers 4 weeks after admission. Muscle biopsy specimens showed hyaline degeneration and infiltration of T cell lymphocytes in the muscle. Renal biopsy specimens showed acute tubular necrosis and some myoglobin casts. No cytomegalovirus antigen was found in renal specimens by immunofluorescence study. From these results, it was determined that a systemic cytomegalovirus infection triggered pancreatitis which caused diabetic ketoacidosis, rhabdomyolysis and acute renal failure.
    No preview · Article · Apr 1992 · Internal Medicine
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    ABSTRACT: Plasma levels of immunoreactive atrial natriuretic peptide (IR-ANP) were measured with a specific radioimmunoassay in 19 undialysed patients with chronic renal failure. At the beginning, an extremely high level of plasma hANP (50 fmol/ml) seen in a patient was rejected with Smirnov's test and was excluded from further statistics. The plasma IR-ANP levels in these patients were significantly higher than those of 19 normal subjects matched with age and sex (10.9 +/- 1.6 vs 5.3 +/- 0.6 fmol/ml, mean +/- SEM, p less than 0.01), and positively correlated with mean blood pressure (r = 0.44, p less than 0.05) and the cardiothoracic ratio (r = 0.65, p less than 0.01), but did not correlate with creatinine clearance (r = -0.38, n.s.). Further, a significant correlation was observed between plasma IR-ANP and urinary protein output (r = 0.47, p less than 0.05). On the other hand, urinary protein output did not correlate significantly with variables such as mean blood pressure, the cardiothoracic ratio or creatinine clearance. Since it has been suggested that ANP enhances glomerular capillary permeability, increased ANP responding to volume overload in those patients may play an important role in increasing urinary protein excretion.
    No preview · Article · Jan 1992 · Endocrinologia japonica
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    ABSTRACT: To clarify the significance of mononuclear phagocytes in IgA nephropathy, renal biopsied materials from 45 patients with the disease were examined by the indirect immunoperoxidase method using anti-human monoclonal antibodies and by ultrastructural peroxidase (PO) cytochemistry. The monoclonal antibodies were FMC32, S-100 (alpha), My4, and LeuM5 for detection of mononuclear phagocytes and HLA-DR for Ia antigens. Mesangial hypercellularity in IgA nephropathy was divided into three grades. The number of monocyte/macrophages per glomerulus differed significantly among the grade of mesangial hypercellularity. In the capillary lumen, monocytes were more numerous in the group with slight mesangial hypercellularity. By contrast, macrophages were often found in the Bowman's space and mesangial area of the glomeruli in the advanced group. In the renal interstitium, the number of monocyte/macrophages per 100 interstitial cells differed significantly among the degree of interstitial damage, and they were observed mainly around sclerotic glomeruli. Ultrastructural PO cytochemistry revealed infiltration of monocytes, exudate macrophages, and/or PO-negative macrophages. Clinicopathological study showed a relationship between the number of monocyte/macrophages per glomerulus and the number of glomerular crescents and the degree of proteinuria. The constancy of the percentage of exudate macrophages and polymorphonuclear leukocytes were observed irrespective of the grade of mesangial hypercellularity. On the other hand, the increasing percentage of PO-negative macrophages and decreasing percentage of monocytes were observed over the grade. These results suggest that mononuclear phagocytes might play an important role in the pathogenesis of mesangial hypercellularity, and irreversible glomerular damage and interstitial tissue injury in IgA nephropathy.
    Preview · Article · May 1991 · Kidney International

  • No preview · Article · Jan 1991

  • No preview · Article · Jan 1990

  • No preview · Article · Jan 1990
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    ABSTRACT: To clarify the molecular nature and dynamics of circulating a human atrial natriuretic polypeptide (αhANP) in chronic renal disease, the plasma concentrations of αhANP were determined by radioimmunoassays using two distinct monoclonal antibodies (MoAbs). One MoAb (10B1) recognized N-terminus of αhANP, while the other (C351) recognized the ring structure. The preliminary studies revealed a close correlation (r=0.97, p<0.0001) between plasma αhANP measured with 10B1 and C351 MoAbs, supporting the theory that the main circulating form is αhANP (1-28). Therefore, the more sensitive radioimmunoassay using MoAb (C351) was used in the present studies. The plasma αhANP was 3.8 ± 1.7 (mean ± SD) in healthy subjects, 2.7 ± 1.4 fmol/ml in patients with chronic glomerulonephritis without renal failure, 16.2 ± 16.8 fmol/ml in patients with chronic renal failure, and 24.3 ± 10.5 fmol/ml in patients under maintenance hemodialysis. Thus, the elevation of plasma αhANP was related to the stages of renal damage. Although the plasma αhANP in 18 patients under maintenance hemodialysis declined significantly (p<0.01) after hemodialysis, their levels (17.9 ± 9.0 fmol/ml) after hemodialysis were still higher than those in healthy subjects. On the other hand, a positive correlation (r=0.65, p<0.05) between αhANP and creatinine in blood was found only in the group of chronic renal failure before maintenance hemodialysis. These results suggest that an impaired metabolism of αhANP in the kidney might play an important role in the elevation of plasma αhANP as well as the stimulation of αhANP secretion caused by the expansion of extracellular fluid.
    No preview · Article · Jan 1989 · Nippon Naibunpi Gakkai zasshi

  • No preview · Article · Jan 1989
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    ABSTRACT: Recently, acute interstitial nephritis (AIN) presenting nephrotic syndrome and renal failure induced by nonsteroidal anti-inflammatory drug (NSAID) has been recognized with increasing frequency. We described here a 43-year-old woman who developed this type of nephropathy after taking NSAID for rheumatoid arthritis. Flurbiprofen (Froben) was assumed to be a causal drug based on a clinical course and a positive result of lymphocyte transformation test. Withdrawal of flurbiprofen therapy led no sufficient improvement, and high-dose steroid therapy done 15 months after the onset resulted in only a minor improvement. So far as we know, this was the second case of AIN associated with flurbiprofen and the youngest in NSAID-induced AIN with irreversible chronic renal insufficiency.
    No preview · Article · Jun 1987 · Japanese journal of medicine
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    ABSTRACT: We report a rare case of eclampsia which occurred during the 18th gestational week in the absence of hydatidiform disease or Rh isoimmunization. In spite of extensive examinations during pregnancy and postpartum, we were unable to find any underlying disease, and the patient returned to being normotensive and non-proteinuric postpartum.
    No preview · Article · Nov 1985 · International Journal of Gynecology & Obstetrics
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    ABSTRACT: A 54-year-old woman who had proteinuria due to stage II membranous nephropathy is reported. She was treated with indomethacin for proteinuria and developed drug-induced hepatitis four months later. Liver dysfunction gradually recovered, but hormonal studies revealed abrupt fall of T3 and T4 and concomitant elevation of TSH levels within a month. Pathological findings of thyroid specimen and positive antithyroglobulin and antimicrosomal antibodies were compatible to chronic thyroiditis. In the second renal biopsy, glomerular deposits of thyroglobulin, thyroid microsomal antigens and IgG were demonstrated by immunofluorescence. Therefore, membranous nephropathy in this patient is presumed to be caused by immune complexes mediated by thyroid constituents. We believe that this is a precious case because continuous changes in T3, T4 and TSH were followed in a course of chronic thyroiditis, especially in the stage of progress to hypothyroidism, and the chronic thyroiditis was shown to be involved in the membranous nephropathy.
    No preview · Article · Feb 1982 · Japanese journal of medicine
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    ABSTRACT: Batter's syndrome characteristically exhibits the constellation of hypokalemic alkalosis, normotensive hyperreninism, hyperalodosteronism, hyporesponsiveness to pressor agent and juxtaglomerular cell hyperplasia. Recently, metabolic mimicry of Batter's syndrome by vomiting, diarrhea, laxatives and diuretics abuse has been reported. We had a 30 year-old female patient who developed so-called pseudo-Bartter's syndrome as the result of surreptitious self-administration of furosemide for about six years. In this case, calcification of bilateral renal medulla was demonstrated. Such adverse reaction has not been reported to date. Moreover, a total 14 cases of pseudo-Bartter's syndrome reported in Japanese literature is reviewed.
    No preview · Article · Aug 1981 · Japanese journal of medicine
  • Hiroshi Maeda · Mahito Nakayama · Daisuke Iwaoka · Tatsuo Sato
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    ABSTRACT: Fluorescence polarization technique was applied for the assay of angiotensin I (Al) in human plasma. In this assay system, fluorescein labeled Al (F-Al), which retained the original antigenicity, and antibody to Al was allowed to interact in a cuvette in the instruments yielding an increase in the fluorescence polarization (P) value. Non-labeled Al in the sample blocked the binding of F-Al to the antibody resulting lower P value. Log of antigen concentration and P value was found to exhibit reverse linear proportionality between 0.05 ng to 2 ng/ml of antigen (Al) concentration. The present method was compared with standard radioimmunoassay method and the result showed that data were compatible with each other. The calculation of P value is automated and three cavity filter and optics of the instrument gave reliable results. The method is fast (less than 2 min), sensitive (less than 10 picomole/ml) and simple (no separation step before readout of the results).
    No preview · Article · Feb 1979 · Advances in Experimental Medicine and Biology
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    ABSTRACT: We described a patient with isolated duodenal varices of the third portion, preoperatively diagnosed by hypotonic duodenography and endoscopy. These varices seemed to be caused by portal hypertension due to liver cirrhosis. The third to the fourth portion of duodenum should be examined carefully in patients with liver cirrhosis, especially with gastrointestinal bleedings of unknown origin.
    No preview · Article · · Journal of Gastroenterology