Biomedical subjects

K Yonemura

Publications and source records attributed to K Yonemura.

At least 19 recordsLinked to original sources

PubMed2004

High ratio of 1,25-dihydroxyvitamin D3 to parathyroid hormone in serum of tuberculous patients with end-stage renal disease.

AIM: Diagnosis of tuberculosis is sometimes difficult because of the low specificity of diagnostic procedures especially in patients on end-stage renal disease (ESRD). As abnormal vitamin D metabolism has been reported in tuberculosis, the aim of the present study was to determine whether serum concentration of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) may be a useful diagnostic indicator of tuberculosis in patients with ESRD. PATIENTS AND METHODS: Serum concentrations of 1,25-(OH)2D3, parathyroid hormone (PTH), and calcium were compared in 6 patients with ESRD and active tuberculosis (ESRD-TB group) and 110 patients with ESRD and no tuberculosis (ESRD group). These parameters were compared before and after treatment for tuberculosis in patients of ESRD-TB group. RESULTS: Hypercalcemia was observed in all 6 patients in the ESRD-TB group. Both higher serum concentration of 1,25-(OH)2D3 and lower serum concentration of PTH were observed in the ESRD-TB group relative to the ESRD group, suggesting enhanced extrarenal production of 1,25-(OH)2D3 and suppressed secretion of PTH by hypercalcemia in the ESRD-TB group. However, these parameters could not be used to distinguish the ESRD-TB group from the ESRD group. The ratio of 1,25-(OH)2D3 to PTH in serum was above 0.9 in the ESRD-TB group and below 0.9 in the ESRD group. Antituberculous treatment reduced this ratio to the range observed in the ESRD group. CONCLUSION: High ratio of 1,25-(OH)2D3 to PTH in serum is noted in active tuberculous patients with ESRD because of enhanced extrarenal production of 1,25-(OH)2D3.

Aged↗

PubMed2003

A case of anaphylactoid shock induced by the BS polysulfone hemodialyzer but not by the F8-HPS polysulfone hemodialyzer.

A 57-year-old woman was admitted because of severe bradycardia and hypotension caused by an anti-arrhythmic agent and beta-blocker. For 19 months before admission, she had been undergoing hemodialysis with an F8-HPS polysulfone membrane hemodialyzer without any complications. In 2 dialysis sessions after admission, when a BS polysulfone membrane was used, she experienced anaphylactoid shock with severe hypotension leading to syncope, dyspnea and vomiting, just after the start of hemodialysis. After the anaphylactoid shock, her dialyzer membrane was changed to a cellulose triacetate membrane and she did not suffer from such attacks. This case indicates that severe anaphylactoid shock may be caused by a biocompatible dialyzer membrane and that the reactions of patients to each polysulfone membrane may differ among polysulfone membranes made by different manufacturers.

Anaphylaxis↗

PubMed2002

Measurement of des-gamma-carboxy prothrombin levels in hemodialysis patients positive for anti-hepatitis virus C antibody.

BACKGROUND: The prevalence of anti-hepatitis virus C (HCV) antibody is much higher in hemodialysis (HD) patients than in the normal population. Recently, blood des-gamma-carboxy prothrombin (PIVKA-II) has been demonstrated as a sensitive marker for the early detection of hepatocellular carcinoma (HCC). In this study, we measured blood PIVKA-II in HD patients positive for anti-HCV antibody or hepatitis B virus surface (HBs) antigen to examine if HD therapy may affect the measurement of PIVKA-II. PATIENTS AND METHODS: Ninety-four stable HD patients who had anti-HCV antibodies (n = 86) or HBs antigen (n = 8) without any evidence of HCC were enrolled in the study (age: 60 +/- 11 years, duration of HD: 17 +/- 10 years, male/female = 63/31). Five patients had liver cirrhosis and another 5 patients received warfarin treatment. We simultaneously measured serum PIVKA-II and alpha-fetoprotein (AFP), and compared the association between these markers and HCV RNA titer and laboratory parameters. RESULTS: Serum PIVKA-II became positive (> or = 40 mAU/ml) in only 5.6% (5/89) of patients without warfarin administration, ranging from 47 to 71 mAU/ml. Seventy out of 89 patients (78.7%) were below 20 mAU/ml. Serum PIVKA-II did not correlate with biochemical parameters including HCV RNA, while serum AFP was significantly correlated with serum AST (r = 0.21, p < 0.05), gamma-GTP (r = 0.21, p < 0.01) and platelet counts (r = -0.29, p < 0.01), respectively. In contrast, 5 patients receiving warfarin had an extremely high PIVKA-II value ranging from 1,930 to 19,900 mAU/ml. PIVKA-II was significantly and inversely correlated with the thrombotest value (r = -0.72, p = 0.01). CONCLUSION: The positivity of blood PIVKA-II in HD patients with hepatitis viremia was identical to that in patients without renal failure. Warfarin treatment dramatically increased serum PIVKA-II more than 1,000 mAU/ml. These findings suggested that HD treatment itself did not affect the measurement of PIVKA-II, but vitamin K deficiency can readily influence the PIVKA-II level in dialysis patients.

Adult↗

PubMed2002

Focal segmental glomerulosclerosis in a case of panhypopituitarism: a possible role of growth hormone treatment.

Panhypopituitarism manifests various symptoms including growth failure, hypothyroidism, adrenal insufficiency and hypogonadism. Dwarfism is an important problem in children with this condition, and long-term treatment with recombinant human growth hormone (GH) is usually required. We report a 24-year-old man with panhypopituitarism complicated by focal segmental glomerulosclerosis (FSGS). The patient had been treated with GH for hypopituitary dwarfism from 3 years of age. Proteinuria was initially noticed at 15 years of age and persisted despite cessation of GH supplementation at 18 years of age. A renal biopsy specimen showed glomerular hypertrophy and limited glomerulosclerosis, compatible with FSGS. To our knowledge, this is the first reported case of panhypopituitarism complicated by FSGS. Our case suggests that GH treatment for dwarfism may induce irreversible glomerular disease.

Adult↗

PubMed2002

Pseudohyperkalemia occurring in a patient with chronic renal failure and polycythemia vera without severe leukocytosis or thrombocytosis.

Pseudohyperkalemia is defined as a serum potassium concentration 0.4 mEq/l greater than the plasma concentration. The basis of this phenomenon is the release of intracellular potassium from platelets, leukocytes, or erythrocytes, commonly in the setting of extreme leukocytosis (> 10 x 10(4)/microl) or thrombocytosis (> 60 x 10(4)/microl). We report a case of pseudohyperkalemia in a patient with chronic renal failure and polycythemia vera without the finding of severe leukocytosis or thrombocytosis (white blood cell count 1.88 x 10(4)/microl and platelet count 37.9 x 10(4)/microl, respectively). The serum potassium concentration was 8.2 mEq/l, while the plasma potassium level was 6.4 mEq/l in a sample obtained simultaneously. The concentrations of platelet factor IV and beta-thromboglobulin, known to be markers of platelet activation, were greater than 100 ng/ml and 200 ng/ml, respectively, indicating that platelet activation may have been related to the development of pseudohyperkalemia in this patient. These findings suggest that pseudohyperkalemia should be considered when hyperkalemia is seen in a patient with chronic renal failure and myeloproliferative disorders.

Aged↗

PubMed2001

Dexamethasone attenuates neutrophil infiltration in the rat kidney in ischemia/reperfusion injury: the possible role of nitroxyl.

Neutrophil infiltration to the tissue, which is one of the important pathogenetic factors in ischemia/reperfusion injury, can be inhibited by glucocorticoids. The purpose of the present study was to clarify the mechanisms by which glucocorticoids inhibit neutrophil infiltration in renal ischemia/reperfusion injury in rats. Pretreatment with dexamethasone significantly attenuated the enhanced neutrophil infiltration and expression of intercellular adhesion molecule-1 induced by renal ischemia/reperfusion. Treatment with nitroxyl anion releaser known as Angeli's salt abolished the beneficial effect of dexamethasone in renal ischemia/reperfusion. Renal dysfunction and tubular damage induced by renal ischemia/reperfusion were not ameliorated by pretreatment with dexamthasone. These results indicate that the attenuation by dexamethasone of neutrophil infiltration and intercellular adhesion molecule-1 expression during renal ischemia/reperfusion may be mediated by the suppressed production of nitroxyl anion. Thus, neutrophil infiltration in renal ischemia/reperfusion injury may be mediated, at least in part, by the enhanced production of nitroxyl anion.

Animals↗

PubMed2001

Tryptophan glycoconjugate as a novel marker of renal function.

PURPOSE: Neither serum creatinine concentration nor creatinine clearance assess renal function accurately. Serum creatinine concentration is affected by muscle mass, and the creatinine clearance overestimates the glomerular filtration rate because of tubular secretion of creatinine. The present study was designed to determine whether serum concentrations of 2-(alpha-mannopyranosyl)-L-tryptophan (MPT), a tryptophan glycoconjugate, can be used as a marker of renal function. METHODS: Clearances of MPT and of inulin were compared in normal rats and in rats with cisplatin-induced acute renal failure. We also compared the clearances of MPT and of creatinine with inulin clearance in 25 patients with chronic renal disease. Serum concentrations of MPT and creatinine as a function of MPT clearance were determined in 108 patients with chronic renal disease. RESULTS: There was strong linear correlation between clearances of MPT and inulin in rats (r = 0.97) and humans (r = 0.87), indicating that renal handling of MPT is similar to that of inulin. In humans, linear regression analyses indicated that MPT was a better indicator of inulin clearance than was creatinine clearance. At the same level of renal function, serum creatinine concentrations tended to be lower in patients with less muscle mass (as indicated by a urinary creatinine excretion <1,000 mg in 24 hours) than in those who excreted >1,000 mg in 24 hours, whereas serum MPT concentrations were not affected by creatinine excretion. CONCLUSION: MPT clearance can replace inulin clearance in the clinical setting. The serum MPT concentration is an accurate measure of renal function even in patients with diminished muscle mass, and thus is a better indicator of renal function than is the serum creatinine concentration.

Acute Kidney Injury↗

PubMed2001

Living-related liver transplantation for type II citrullinemia using a graft from heterozygote donor.

BACKGROUND: Type II citrullinemia (CTLN2) characterized by a liver-specific argininosuccinate synthetase deficiency is an adult onset genetical disorder caused by the mutation of SLC25A13 gene, which results in fulminant hyperammonemia often with poor prognosis. METHODS: A 16-year-old Japanese boy presented fulminant hyperammonemia and encephalopathy and recovered after aggressive medical treatment. The patient was diagnosed as CTLN2 by plasma amino acid pattern and detection of the mutated SLC25A13 gene. We performed living-related liver transplantation (LRLT) using a graft from the genetically proven heterozygote father. RESULTS: Serum amino acid concentration was normalized within a day after transplantation without protein restriction and medication. The patient's postoperative course was natural. The patient is back in school 6 months after surgery. CONCLUSIONS: Living-related liver transplantation using a graft from genetically proven heterozygote donors might be a permissible treatment modality for CTLN2. Long-term observation may be necessary to make a definite conclusion possible.

Adolescent↗

PubMed2001

Sequence of events in the glomerular capillary wall at the onset of proteinuria in passive Heymann nephritis.

Proteinuria in passive Heymann nephritis (PHN) results from complement-mediated glomerular injury, since complement depletion with cobra venom factor (CVF) prevents proteinuria. However, there are no comprehensive morphological studies identifying the sites of injury leading to onset of proteinuria. To address this issue, we attempted to locate sites of injury involved in the onset of proteinuria in PHN. PHN was induced in intact Munich-Wistar rats (PHN-rats, examined at days 3, 5, and 7) and in complement-depleted rats (CVF treated, PHN-CVF-rats, examined at days 3 and 5). The distribution of endogenous albumin in the glomerular basement membrane (GBM) was studied in in situ drip-fixed glomeruli using immunogold immunocytochemistry, and glomerular anionic sites were visualized by polyethyleneimine staining. In addition, the ultrastructural localization of an epitope recognized by a proteinuria-inducing monoclonal antibody (called 5-1-6) directed against the slit diaphragm was examined. Significant proteinuria was seen in intact PHN-rats, starting at day 5. The intensity of gold labeling for endogenous albumin was significantly increased at the outermost site of the GBM (GBM interfacing foot process and the filtration slit, designated area O) at day 3 in both PHN-rats and PHN-CVF-rats in comparison to untreated controls. At day 5, labeling for albumin in area O was decreased in PHN-rats, but not in PHN-CVF-rats, where it was then higher; in PHN-rats, some areas between epithelial cells and subepithelial deposits were almost free of albumin labeling at day 7. There was no evidence of epithelial cell detachment in any group at day 5, but on day 7 limited focal detachment was seen exclusively in PHN-rats. In proteinuric rats, amorphous material that stained for albumin could be seen in the urinary space, without any exocytosis of labeling by glomerular epithelial cells. A significant reduction of intensity of staining for anionic sites was seen in parallel in both groups, but only in the regions of the lamina rara externa adjacent to subepithelial deposits. This local loss of charge might contribute to enhanced permeability to albumin in both PHN- and PHN-CVF-rats. Changes in the appearance of the filtration slits and in the density and distribution of antigen recognised by monoclonal antibody 5-1-6 were similar in PHN- and PHN-CVF-rats at day 5. Complement depletion prevented neither the reduction in anionic sites of the GBM nor the changes in the slit diaphragm observed. These data suggest that albumin leakage between the epithelial cell and the GBM (area O) could occur in PHN-rats, perhaps as a result of epithelial foot-process changes. This may be the final link in the chain of events responsible for the onset of proteinuria in PHN.

Albumins↗

PubMed2001

Cytokines and cell cycle regulation in the fibrous progression of crescent formation in antiglomerular basement membrane nephritis of WKY rats.

Cytokines may regulate cell proliferation by cell-cycle-regulatory proteins, in which cyclin-dependent kinase inhibitors (CDKI) inhibit cell proliferation. We investigated whether CDKI p21 or p27, both of which are potentially regulated by transforming growth factor (TGF)-beta, a key cytokine in fibrogenesis, are involved together with TGF-beta and/or platelet-derived growth factor (PDGF) in the fibrous progression of glomerular crescent formation and examined the sequential change in the cell type and the cellular background of myofibroblasts in crescent formation. Crescentic glomerulonephritis (GN) was induced by i.v. injection of rabbit antirat glomerular basement membrane antiserum in WKY rats. Animals were killed 1, 2, 3 and 4 weeks after the induction of GN, and their kidneys were processed for immunohistochemical examination. After 1 week more than 85% of glomeruli showed cellular crescents, which became fibrocellular with decreased cellularity by 4 weeks. ED 1-positive macrophages were components of crescent cells in about 44% at 1-2 weeks, and this proportion declined markedly afterwards. Alpha smooth muscle actin (alpha SMA, a marker for myofibroblasts)-positive cells were found in Bowman's epithelial cells (BEP) and in some crescent cells at 1 week, becoming major components of crescent cells by 4 weeks (about 40%). It was 2 weeks before invasion of alpha SMA-positive interstitial cells into glomeruli was evident. PDGF-B and PDGF receptor beta-positive cells, indicating possible targets for PDGF, were found in BEP adjoining crescent formation almost exclusively from 1 to 2 weeks. By contrast, both TGF-beta receptor types I- and II-positive cells, indicating possible effectors for TGF-beta, were found in BEP and crescent formation, and the percentage of these in the crescent formation did not change until 4 weeks (about 32%). Cells with positive immunostaining for proliferating cell nuclear antigen and cyclin A, markers for cell proliferation, in the crescent formation peaked in number and proportion at 1-2 weeks, then decreased. In contrast, cells with positive immunostaining for p21 and p27, CDKI, were sparse at 1 week, and then increased markedly in number and in proportion, peaking at 3 (39.6%) or 2-3 weeks (about 25-30%), respectively. The present study demonstrates that restrained expression or a transient increase in p21 and p27 may be associated with proliferation or with inhibited proliferation of crescent cells, most of which are macrophages and myofibroblasts. The action, of PDGF and TGF-beta may contribute to the recruitment of myofibroblasts into the crescent. The action of TGF-beta on crescent cells might be linked to the expression of p21 and/or p27.

Actins↗

PubMed2001

Complication of oliguric acute renal failure in patients treated with low-molecular weight dextran.

Acute renal failure (ARF) is a well-documented but infrequent complication in patients treated with low-molecular weight dextran (LMWD). We herein report 3 cases of oliguric ARF following the administration of dextran-40. One case developed ARF totally after 1.200 g of LMWD administration. In contrast, two cases having increased serum creatinine developed oliguria despite the acceptable therapeutic doses (totally 450 and 650 g). Contrast media was also co-administered in these patients. Plasma exchange (PE), double filtration plasmapheresis (DFPP), or continuous hemodiafiltration (CHDF) but not hemodialysis (HD) reduced circulating dextran concentrations by 35-44% during a single session. All patients completely recovered from ARF by 14-32 days after the treatment. Our cases suggested that radiocontrast could predispose to the development of LMWD-induced ARF especially in patients having pre-existing renal dysfunction. In addition, PE, DFPP and CHDF afforded a beneficial effect for removing accumulated LMWD from the circulation.

Acute Kidney Injury↗

PubMed2001

Potential therapeutic effect of simvastatin on progressive renal failure and nephrotic-range proteinuria caused by renal cholesterol embolism.

We report our experience with a 62-year-old Japanese man with cholesterol crystal embolism after angiographic procedures performed because of intermittent claudication. In addition to progressive renal failure and nephrotic-range proteinuria, cutaneous ischemia, consisting of livedo reticularis in the lower limbs and digital necrosis at the tip of the right toe, and fundoscopic findings showing several white spots in the branches of retinal artery were also observed. Progressive renal failure and nephrotic-range proteinuria were halted just after treatment with simvastatin. Thus, simvastatin can exert a beneficial therapeutic effect on renal cholesterol embolism.

Anticholesteremic Agents↗

PubMed2001

Hypercalcemia in a patient with B-cell acute lymphoblastic leukemia: a role of proinflammatory cytokine.

The complication of hypercalcemia is reported to occur only in 2.5-4.8% of patients with acute lymphoblastic leukemia (ALL). We herein report a 53-year-old female patient with early B-cell ALL, complicated with extreme hypercalcemia (15.2 mg/dL). Bone X-ray revealed osteolytic changes in many locations. Serum 1,25(OH)2vitaminD3 and parathyroid hormone (PTH) levels were suppressed below normal ranges on admission. The circulating parathyroid hormone-related protein (PTHrP) value was within a normal range (< 1.1 pmol/L). Serum concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and soluble IL-2 receptor were increased to 72 pg/ml, 25.3 pg/ml, and 1469 U/ml, respectively. Following the induction chemotherapy, the serum calcium level was promptly normalized accompanied with decreases in serum TNF-alpha, IL-6 and soluble IL-2 receptor values to 34 pg/ml, 6.35 pg/ml, and 737 U/ml, respectively. Serum PTHrP values remained within detectable levels. To our knowledge, this is the first case of B-cell ALL in a patient who developed hypercalcemia with elevated concentrations of TNF-alpha, IL-6, and soluble IL-2 receptor, but not related to PTHrP. High circulating proinflammatory cytokines may have contributed to development of ALL-induced osteolysis and hypercalcemia in the present case.

Biomarkers, Tumor↗

PubMed2001

Tuberculous arthritis mimicking neoplasm in a hemodialysis patient.

Hemodialysis patients are known to develop the complication of extrapulmonary tuberculosis more frequently than the general population. Tuberculous arthritis is a rare form of extrapulmonary tuberculosis and is reported to occur in approximately 1% of cases in nonuremic patients. Only 3 cases in dialysis patients, who were not proven by a bacterial culture or had died before treatment, have been reported. We report herein a culture-proven case of tuberculous arthritis developing at the sternoclavicular joint, which initially mimicked an apparent neoplasm in a hemodialysis patient. A favorable outcome was obtained after antituberculous therapy. Tuberculosis must be considered one of the most significant diagnoses in hemodialysis patients who present with a tumor-like lesion.

Aged↗

PubMed2001

Hypertension and neurovascular compression of the left lateral medulla oblongata in ischemic stroke.

Hypertension is a major risk factor for stroke. Neurovascular compression (NC) of the left ventrolateral medulla oblongata may cause arterial hypertension. We evaluated the relationship between the two ischemic stroke patients. We classified 69 patients under 50 years old (49 men and 20 women, aged 43.6 +/- 7.3 years) based on magnetic resonance imaging findings as follows: NC patients (n = 38; 10 with NC on the right side, 18 with NC on the left side, and 10 with NC on both sides) and non-NC patients (n = 31). We compared the following clinical characteristics between the two groups: (1) risk factors for stroke, including hypertension, diabetes mellitus, hypercholesterolemia, and smoking and (2) stroke subtype. Hypertension was more frequent in the NC group than in the non-NC group (58 vs. 19%, p = 0.001). Hypertension was more frequent in patients with left-side NC than in those with right-side NC (78 vs. 20%, p = 0.005). No other differences were observed between the two groups. Twelve patients presented with atherothrombotic stroke, 16 with cardioembolic stroke, 24 with lacunar stroke and 17 with stroke of miscellaneous etiology. NC was significantly more common in patients with lacunar stroke as compared with those affected by other stroke subtypes (p = 0.015). We found a significant relationship between hypertension and NC of the ventrolateral medulla oblongata on the left side in ischemic stroke patients younger than 50 years of age. Some patients with lacunar stroke may have hyptertension related to NC.

Adolescent↗

PubMed2001

Decreased plasma and cerebrospinal fluid glutamine concentrations in a patient with bialaphos poisoning.

A 47-year-old Japanese woman undergoing maintenance hemodialysis (HD) was admitted to our hospital because of poisoning with the herbicide bialaphos. Respiratory arrest and loss of consciousness ensued rapidly, accompanied by convulsions and nystagmus. Treatment with HD and direct hemoperfusion, followed by HD alone, effectively removed bialaphos and its chief toxic metabolite (L-AMPB) from the circulation (bialaphos decreased from 0.33 to < 0.05 microg/ml and L-AMPB from 14 to 0.86 microg/ml). The glutamate concentration improved gradually after the removal of bialaphos and L-AMPB from plasma (plasma glutamate concentration: 250.4 nmol/l on day 5 to 120.6 nmol/l on day 26). Decreased glutamine concentration in cerebrospinal fluid was demonstrated for the first time as well as in plasma, indicating glutamine synthetase inhibition not only in plants but also in humans by bialaphos poisoning.

Adult↗

PubMed2001

Progressive renal failure and blindness due to retinal hemorrhage after interferon therapy for hepatitis C virus-associated membranoproliferative glomerulonephritis.

We treated a 67-year-old Japanese woman with membranoproliferative glomerulonephritis (MPGN) and chronic active hepatitis associated with hepatitis C virus (HCV) infection. Treatment commenced with a daily dose of 6 MU IFN alpha-2b for 2 weeks, which was changed to three times weekly thereafter. After 2 weeks, HCV RNA in the serum was undetectable and there was a concomitant reduction in proteinuria. Treatment with IFN alpha-2b was discontinued because of severe headache and fever. Five weeks after the discontinuation of IFN alpha-2b, the patient experienced the sudden onset of visual loss due to retinal hemorrhage. Subsequently, proteinuria and renal function progressively deteriorated though HCV RNA was undetectable. This case exemplifies the need for careful monitoring of renal function and retinal lesions not only in patients receiving IFN but also in those following the discontinuation of IFN treatment.

Aged↗

PubMed2001

Diffusion-weighted MR imaging in a case of mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes.

In a patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS), both T2- and diffusion-weighted MR imaging revealed lesions as hyperintense areas in the occipital lobes early after strokelike episodes. In these lesions, no significant reduction in apparent diffusion coefficient was noted. Apparent diffusion coefficient mapping may help to differentiate strokelike episodes in MELAS from acute ischemic stroke. The strokelike episodes may be related to vasogenic edema and hyperperfusion, which were suggested by our single-photon emission CT and MR imaging studies.

Adult↗