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Biomedical subjects

Y Nakamoto

Publications and source records attributed to Y Nakamoto.

At least 127 records · Page 7Linked to original sources
PubMed1990

Absence of nocturnal fall in blood pressure in elderly persons with Alzheimer-type dementia.

Circadian changes of the blood pressure and heart rate in elderly normotensive bedridden patients with severe dementia of the Alzheimer type (group D) were compared with those in elderly normotensive bedridden patients without dementia (group R), normotensive subjects with normal daily activity (group N), and hypertensive patients with normal daily activity (group H). In groups R, N, and H, the blood pressure increased in the afternoon and decreased at midnight; in group D, however, although it increased in the afternoon, it did not decrease at night. The circadian changes of the heart rate were similar in all four groups, showing maxima in the afternoon and minima at midnight. Thus, a specific alteration was found in the circadian rhythm of the blood pressure in patients with Alzheimer-type dementia.

Activities of Daily Living↗
PubMed1990

Molecular epidemiologic evidence for association of thermostable direct hemolysin (TDH) and TDH-related hemolysin of Vibrio parahaemolyticus with gastroenteritis.

The Kanagawa phenomenon induced by the thermostable direct hemolysin (TDH) of Vibrio parahaemolyticus is almost exclusively associated with clinical strains, and TDH has been considered an important virulence factor. However, Kanagawa phenomenon-negative strains isolated from patients with diarrhea have recently been shown to produce TDH-related hemolysin (TRH). We studied the distribution of the tdh gene encoding TDH and the trh gene encoding TRH in vibrios by hybridization analyses. The presence or absence of the tdh gene and the trh gene in 285 strains of V. parahaemolyticus was examined by the DNA colony hybridization test with a tdh gene-specific probe and a newly constructed trh gene-specific probe. For assessment of the importance of TRH, many Kanagawa phenomenon-negative clinical strains (35.4% of all strains) were included. Of 214 clinical strains of V. parahaemolyticus, 112 strains (52.3%) had the tdh gene only, 52 strains (24.3%) had the trh gene only, and 24 strains (11.2%) carried both the tdh and the trh gene. The coexistence of the tdh and trh genes in these 24 strains was confirmed by Southern blot hybridization analysis. Of 71 environmental strains, 5 strains (7.0%) hybridized very weakly with the trh gene probe and none hybridized with the tdh gene probe. These results suggest that TRH as well as TDH is an important virulence factor of V. parahaemolyticus. Among 118 strains of other Vibrio species examined for the trh gene, only 1 strain of Vibrio furnissii gave a very weak hybridization signal. Among 48 representative trh gene-positive strains of V. parahaemolyticus, only 18 strains (37.5%) were found to produce TRH in culture medium when examined by a sensitive enzyme-linked immunosorbent assay method.

Blotting, Southern↗
PubMed1990

Localization of renal erythropoietin and the role of Ia antigen expression in hypoxic rat glomeruli.

Erythropoietin (EPO) producing cells were examined by the immunofluorescent antibody technique, and the alterations in the Ia antigen expression in glomeruli by hypoxic stimuli. Antisera were obtained from rabbits immunized with pure human EPO. Positive fluorescence was localized in glomerular mesangial regions of the hypoxic rat kidney. Although hypoxia showed neither increase in the number of glomerular cells nor hypertrophy of the mesangial matrix, it induced an increase of the Ia antigen expressions in glomeruli. The peak of the increase occurred 2 hr after hypoxia and then decreased until 24 hr later. The increase of Ia antigen after 2 hr of hypoxic stimuli was 176.5 +/- 7.0% of normal controls, and ranged from 151 to 209%. In conclusion, Ia positive cells in glomeruli may have some relationship to the stimulation of EPO production.

Animals↗
PubMed1990

The inhibitory factors of hematopoiesis in chronic hemodialysis patients treated with recombinant human erythropoietin.

In order to clarify possible factors responsible for varying responses in uremic patients treated with recombinant human erythropoietin (rHuEPO), we determined the inhibitory effects of ten uremic sera on the erythroid progenitors (CFU-E) and erythroid bursts (BFU-E). We also measured plasma EPO titers, Fe, UIBC, ferritin, PTH-C, beta 2-microglobulin, and aluminum in all ten patients. The inhibitor of CFU-E but not BFU-E, was present in the serum of the single anemic patient whose recovery took longer after the administration of rHuEPO. He did not have such conditions as iron deficiency, excess of aluminum, or chronic inflammation. The remaining patients, who had no CFU-E or BFU-E inhibitors, were good responders to rHuEPO. In none of ten patients were there inhibitors of granulocyte-macrophage progenitors (CFU-GM) or any differences in the other parameters. Although the inhibitory factor of CFU-E can be overcome with a larger dose, its prior determination may be useful to set out minimal effective dose of EPO treatment.

Adult↗
PubMed1990

Allergic granulomatosis and angiitis (Churg-Strauss syndrome) presenting as acute acalculous cholecystitis.

A patient with bronchial asthma and hypereosinophilia developed acute acalculous cholecystitis. Histopathologic study of the surgically removed gallbladder revealed allergic granulomatosis and angiitis (Churg-Strauss syndrome). Allergic granulomatosis and angiitis having acute acalculous cholecystitis as an initial manifestation is rare. It should be recognized that acute acalculous cholecystitis may be the initial sign of a systemic vasculitis, specifically allergic granulomatosis and angiitis.

Acute Disease↗
PubMed1989

Mesangiolytic glomerulonephritis associated with Takatsuki's syndrome: an analysis of five renal biopsy specimens.

Renal biopsy specimens from five patients with Takatsuki's syndrome were studied. Proteinuria and hematuria were modestly positive in four cases and three cases, respectively. One case demonstrated early azotemia, while four cases revealed normal serum creatinine levels. All cases displayed glomerular enlargement and lobulation, mesangial cell proliferation, and double contour structure, simulating membranoproliferative glomerulonephritis. It is noteworthy that mesangial loosening was also detected in the renal biopsy specimens of this study. This change was present diffuse-globally in the well-developed cases and focal-globally or segmentally in the developing cases. In addition, various morphologic expressions were observed, ie, microaneurysms congested with RBCs, tentatively termed mesangial hyaline thrombi, nodule-like lesions, and tiny to small-sized mesangiolytic lesions. Since all these features could be explained by low-grade mesangiolysis, the renal alteration associated with this syndrome was termed mesangiolytic glomerulonephritis. Humoral factor(s) also toxic to the mesangium were implicated.

Adult↗
PubMed1989

Anti-histone autoantibodies in ddY mice, an animal model for spontaneous IgA nephritis.

The ddY mice are known to develop spontaneous glomerulonephritis resembling human IgA nephritis after 40 weeks of age. A sharp rise of circulating polyclonal IgG and IgA is also observed at this stage. Since these overproduced immunoglobulins seem to be related to the development of murine glomerulopathy, antigen-antibody interactions between renal tissue proteins and serum immunoglobulins were analyzed by Western blotting in ddY mice before and after 40 weeks of age. Serum IgG at 50 weeks reacted with an 18-kDa renal tissue protein which was identified as histone H3, as well as with histone H1. Renal histones were extracted along with IgG from the murine kidney at 50 weeks in a high salt soluble fraction. Serial studies of anti-histone antibodies by enzyme-linked immunosorbent assay showed that IgG class antibodies markedly increased after 40 weeks of age. IgA class antibodies mildly increased after 56 weeks of age. Anti-DNA antibodies were not detected. These results demonstrate that ddY mice also develop mainly IgG class and partly IgA class anti-histone autoantibody after 40 weeks of age, and that histone-anti-histone complexes may contribute to the development of murine glomerulopathy. Although anti-histone antibodies have been reported in lupus mice, ddY mice differ from these mice in that no anti-DNA antibodies develop.

Animals↗
PubMed1989

Carbamazepine-induced granulomatous necrotizing angiitis with acute renal failure.

A 42-year-old male treated with carbamazepine developed a skin eruption in the trunk, followed by acute renal failure. Laboratory data revealed leukocytosis (15,700/mm3) with eosinophilia (37%). A renal biopsy disclosed granulomatous necrotizing angiitis that differed from classic periateritis nodosa and hypersensitivity angiitis. All drugs were discontinued immediately, and there was a gradual improvement of the renal function. A carefully performed provocation test using carbamazepine was positive. We made a diagnosis of carbamazepine-induced granulomatous necrotizing angiitis. Only 6 cases of drug-induced granulomatous angiitis have been reported prior to the present case. Drug-induced granulomatous angiitis is often fatal. The present report suggests the importance of making a diagnosis quickly, and providing adequate treatment in order to prevent a fatal course.

Acute Kidney Injury↗
PubMed1989

Erythropoietic activity in culture media conditioned by rat mesangial cells.

Using a tissue culture technique we examined erythropoietin (EPO) producing cells in rat glomeruli. In 5 out of 6 independent glomerular cell cultures, EPO activity was found in the mesangial-cell proliferating phase, but not in the epithelial-cell proliferating phase. Therefore, mesangial cells seemed to be EPO producing cells.

Animals↗
PubMed1989

High-yield purification of the complex-forming glycoprotein in urine from normal and abnormal subjects.

Ordinary methods for purification of complex-forming glycoprotein (protein HC) or alpha 1-microglobulin, a protein closely related to protein HC, require either large volumes of urine or special collection of urine specimens from patients with tubular proteinuria. Here we describe a fast, efficient procedure for isolating protein HC in high yield from urines from healthy and diseased subjects, with use of Cibacron blue, hydroxylapatite, and gel chromatography. Using this procedure, we also obtained a considerable amount of polymeric protein HC from the urine of a patient with chronic renal failure. The pattern of charge heterogeneity and immunoreactivity with anti-protein HC differed between the polymeric and monomeric forms of protein HC. We also observed a variability in charge heterogeneity of protein HC among patients with renal disorders. These results demonstrate that this purification method is useful for further studies to elucidate the biochemical properties of protein HC and its clinical significance in renal disorders.

Alpha-Globulins↗
PubMed1988

Autoantibody against erythrocyte protein 4.1 in a patient with autoimmune hemolytic anemia.

We observed the presence of a new autoantibody, anti-erythrocyte protein 4.1, in a patient with autoimmune hemolytic anemia (AIHA). Western blotting analysis revealed that IgG from the patient's plasma reacted with erythrocyte protein 4.1. However, among other patients with hemolytic diseases (six having AIHA and three each having either hereditary spherocytosis, elliptocytosis, or lead poisoning) as well as among control subjects, no antibody activity to protein 4.1 was observed. In addition to the anti-protein 4.1 antibody, two different kinds of anti-erythrocyte antibodies were detected by conventional serological studies in this patient. One of them was an anti-Ena-like antibody in the eluate from the patient's erythrocytes, while another was the anti-S-specific antibody in the plasma. An elution study and an absorption study using S antigen-positive erythrocytes demonstrated that the anti-protein 4.1 antibody differed from both the anti-Ena-like antibody and the anti-S antibody. Familial analysis of the patient revealed the same antibody in her brother, who did not have hemolytic anemia. These results demonstrate that anti-protein 4.1 antibody is considered to be included in the spectrum of anti-cytoskeleton autoantibodies, which have been observed in patients having increased cell lysis as well as in healthy subjects.

Anemia, Hemolytic, Autoimmune↗
PubMed1987

Mesangial proliferative glomerulonephritis. Natural history and effects of dextran sulfate.

We evaluated 246 cases having clinically primary chronic glomerulonephritis and histologically mesangial proliferative glomerulonephritis of varying degrees. 190 patients conservatively followed with serial measurements of GFR served as delineating the natural history. The remaining, randomly selected 56 subjects were treated with Dextran sulfate, a mild anticoagulant, for 7 to 56 months (average, 25.4). 55 cases underwent repeated renal biopsy at the mean interval of 3.3 years. It became evident clinically and morphologically that the severity of diffuse mesangial proliferation and the presence of focal and segmental lesions in more than 20% were two critical determinants of the natural history. All cases with mild mesangial proliferative alteration alone survived more than 10 years, but none of the patients with global sclerosis in more than 50% in the initial biopsy did. 10-year survival rates in mild, and moderate or greater mesangial proliferation with the focal-segmental lesions were 45.0% and 19.3%, respectively. In the treated group, renal function improved or was maintained, along with histologic confirmation in some, during the follow-up period. Moreover, the survival rate of subjects with global sclerosis in more than 50% ameliorated beyond the natural history. Thus, Dextran sulfate appeared promising for a possible suppression of the coagulatory process associated with the focal-segmental lesions.

Adolescent↗