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K Mitamura

Publications and source records attributed to K Mitamura.

At least 55 records · Page 3Linked to original sources
PubMed1999

[Optical immunoassay test for rapid detection of influenza A and B viruses: an evaluation].

The optical immunoassay test (FLU OIA, BioStar, USA) for rapid detection of influenza A and B viral antigens was compared with viral isolation in cell culture. A total of 103 respiratory specimens were tested on 75 pediatric patients with acute respiratory illnesses. Influenza viruses were recovered in 40 specimens (type A: 5, Type B: 35). FLU OIA demonstrated 80.0% sensitivity and 68.8% specificity for nasopharyngeal aspirates and 36.7% sensitivity and 83.9% specificity for throat swabs. We also tested FLU OIA, retrospectively, using 78 supernatant samples from pediatric patients with influenza A virus infection frozen after cell culture. FLU OIA demonstrated 91.4% sensitivity and 92.3% specificity for nasopharyngeal aspirates and 50.0% sensitivity and 91.7% specificity for throat swabs diluted in viral transport media. Nasopharyngeal aspirates showed higher sensitivity than throat swabs for detection of influenza virus by FLU OIA. We believe this rapid test kit is useful for the detection of influenza A and B viruses.

Adolescent↗
PubMed1999

Levels of 24,25-dihydroxyvitamin D3, 25-hydroxyvitamin D3 and 25-hydroxyvitamin D3 3-sulphate in human plasma.

The concentrations of (24R)-24,25-dihydroxyvitamin D3[24,25(OH)2D3], 25-hydroxyvitamin D3[25(OH)D3] and its 3-sulphate [25(OH)D3(3)S] in the plasma of healthy subjects, patients with chronic renal failure, patients with climacteric syndrome, pregnant women and foetuses were determined using the enzyme-linked immunosorbent assay and high-performance liquid chromatography. 25(OH)D3(3)S was not detected in about one-third of the plasma samples from patients with chronic renal failure (n = 26). The three metabolites in maternal plasma reached the highest levels in the second trimester of pregnancy followed by a decrease to the values obtained in the first trimester. Older healthy women (age range 44-71 years) showed higher levels of 24,25(OH)2D3 and 25(OH)D3 in the plasma than did young healthy women (age range 21-29 years), whereas no clear difference was observed between the older healthy women and patients with climacteric syndrome. The level of 25(OH)D3(3)S in the plasma was higher in the latter patients than in healthy women.

24,25-Dihydroxyvitamin D 3↗
PubMed1998

Irregular regeneration of hepatocytes and risk of hepatocellular carcinoma in chronic hepatitis and cirrhosis with hepatitis-C-virus infection.

BACKGROUND: Hepatocellular carcinoma (HCC) commonly develops in patients with chronic hepatitis or cirrhosis of the liver caused by hepatitis-C-virus (HCV) infection. We prospectively studied whether irregular regeneration of hepatocytes is a risk factor for HCC in these patients. METHODS: 242 patients were enrolled after liver biopsy and followed up by ultrasonographic scanning every 3 months. We examined age, sex, platelet count, the diagnosis of cirrhosis or chronic hepatitis, liver-cell dysplasia, and irregular regeneration. We classified irregular regeneration as slight or severe, based on histological expression of pleiomorphism, anisocytosis, bulging, and map-like distribution of hepatocytes. FINDINGS: 37 of 63 patients with cirrhosis and 26 of 179 with chronic hepatitis were judged to have severe irregular regeneration. HCC was diagnosed in 33 of 63 patients with cirrhosis (29 had severe irregular regeneration) and 12 of 179 patients with chronic hepatitis (11 had severe irregular regeneration) during mean follow-up of 5.5 years (SD 4.1; range 1-16). Multivariate analysis with a proportional-hazards model showed severe irregular regeneration (relative risk 15.1 [95% CI 5.6-40.7], p<0.0001) and a diagnosis of cirrhosis (3.8 [1.7-8.2], p=0.0008) to be significant risk factors for HCC. Within the diagnostic categories, irregular regeneration was also significant (cirrhosis 6.8 [2.1-21.9], p=0.0014; chronic hepatitis 28.5 [2.9-276.4], p=0.0038). INTERPRETATION: We recommend that liver biopsy to look for irregular regeneration should be done in patients with HCV-related chronic liver diseases. Those with severe irregular regeneration should be followed up carefully.

Adult↗
PubMed1998

V gene sequences of lupus-derived human IgM anti-ssDNA antibody: implication for the importance of the location of DNA-binding amino acids.

Binding and structural characteristics of human IgMk anti-ssDNA antibody 7B3 were determined. 7B3 was derived from Epstein-Barr virus-transformed peripheral blood B cells of a lupus nephritis patient. Purified 7B3 bound ssDNA from various species, but not dsDNA or structurally unrelated antigens. The relative avidity of 7B3 was high in comparison with IgM anti-DNA antibodies previously described by other investigators. Sequence analysis showed that 7B3 used VH26/D35/JH3 and Humkv328h5/JK1 germline genes, and had a few mutations in the complementarity determining regions (CDRs). No arginine was expressed in the heavy-chain CDR3. However, the putative DNA contact sites, based on the previous crystallographic and computer modeling studies, were occupied by mutated or germline-derived basic and polar amino acids. These results suggest that a minimally mutated IgM anti-ssDNA antibody with a paucity of arginines could display monospecificity and high avidity if DNA-binding amino acids are enriched at the critical DNA contact sites.

Amino Acid Sequence↗
PubMed1998

Isolation of anti-nucleosome antibodies from the plasma of lupus nephritis patients.

Anti-nucleosome antibodies, which recognise conformational epitopes consisting of histone and DNA in chromatin, have been described in autoimmune diseases. In this study, an attempt was made to isolate anti-nucleosome antibodies from the anti-DNA-depleted plasma IgG of two lupus patients either with or without nephritis by nucleohistone affinity chromatography. The purified nucleohistone-binding antibodies bound to nucleohistone in a specific manner and contained enriched anti-histone antibodies. However, adsorption of the purified antibodies with histone revealed that the nephritis patient-derived antibodies contained nucleohistone-specific antibodies. Although such purified antibodies may not recognise native structures of nucleosomes, this chromatography may provide a method to isolate and determine the fine specificity of anti-nucleosome antibodies in various autoimmune diseases.

Antibodies, Antinuclear↗
PubMed1998

Surgical treatment of Cronkhite-Canada syndrome associated with protein-losing enteropathy: report of a case.

PURPOSE: The case of a patient with Cronkhite-Canada syndrome, who developed a protein-losing enteropathy, is reported. METHODS: After localization of the protein-losing region, a right colectomy was performed. RESULTS: Hypoproteinemia and ectodermal changes improved postoperatively. CONCLUSIONS: Surgery is an effective treatment for protein-losing enteropathy in Cronkhite-Canada syndrome. Ectodermal changes improve after correcting malnutrition.

Female↗
PubMed1998

Rectal mucosal hemodynamics, evaluated by reflectance spectrophotometry, in patients with chronic hepatitis.

To evaluate rectal mucosal hemodynamics in patients with chronic hepatitis, we employed reflectance spectrophotometry and examined the results in relation to the presence and severity of chronic hepatitis. Twenty-six patients with histologically diagnosed chronic hepatitis and 21 controls were examined for rectal vascular findings by endoscopy. Indices (I) of rectal mucosal oxygen saturation (ISO2) and rectal mucosal hemoglobin (IHb) concentration were measured. To minimize the effects of systemic anemia, the IHb was divided by blood Hb concentration, giving the rectal index for Hb (RHb). The relationship between rectal mucosal hemodynamics and the histological grade of chronic hepatitis was studied. Rectal vascular lesions were observed in three patients with chronic hepatitis (11.5%). The RHb in patients with chronic hepatitis was significantly higher than that in the controls (5.74 +/- 0.71 and 4.82 +/- 1.12, respectively; P < 0.01). There was no significant difference in ISO2 levels (44.23 +/- 5.84 and 41.94 +/- 4.91, respectively). No significant correlation was observed between rectal mucosal hemodynamics and the histological severity of chronic hepatitis, although rectal mucosal hemodynamics changed in patients with chronic hepatitis. Early vascular changes were observed in the rectal mucosa of patients with chronic hepatitis.

Adult↗
PubMed1998

Seroprevalence of immunoglobulin G antibodies against Helicobacter pylori among endoscopy personnel in Japan.

BACKGROUND: The seroprevalence of immunoglobulin G antibodies against Helicobacter pylori in endoscopy personnel was determined to investigate whether gastrointestinal endoscopists and endoscopy nurses in Japan are at an increased risk for H. pylori infection and to clarify risk factors for H. pylori infection during endoscopy. METHODS: One hundred twenty-one gastrointestinal endoscopists and endoscopy nurses provided personal information, including their observance of infection-control measures, by means of self-administered questionnaire. One hundred one age-matched healthy individuals undergoing routine physical examinations served as controls. Serum samples from each subject were examined with enzyme-linked immunosorbent assay for the presence of IgG antibodies against H. pylori. RESULTS: Among younger subjects (< 40 years old), endoscopists and endoscopy nurses had higher seropositive rates than did control subjects (p < 0.05). Among older subjects (> or = 40 years old), the seropositive rate did not differ between endoscopy personnel and control subjects (p = 0.2174). However, among older seropositive subjects, endoscopy personnel had significantly higher antibody titers than did control subjects (p < 0.01). Older seropositive endoscopists performed significantly more examinations per month than did their seronegative colleagues (p < 0.05). Furthermore, younger seropositive endoscopy nurses performed significantly more examinations per month than did seronegative nurses (p < 0.05). CONCLUSIONS: Gastrointestinal endoscopists and endoscopy nurses in Japan are at high risk for H. pylori infection. The risk of H. pylori infection is correlated with the frequency of endoscopic examinations, especially in older gastrointestinal endoscopists and younger endoscopy nurses.

Adult↗
PubMed1998

[Immunization with one dose of inactivated influenza vaccine].

In the winter of 1996, a total of 71 working adults from 20 to 60 (m = 37.3) years of age were immunized with one or two doses of inactivated influenza vaccine formulated in Japan. The reciprocal geometric mean hemagglutination inhibition antibody titers [mean HI] and the percentage with a hemagglutination inhibition titer of > or = x 128 [percent > or = x 128], against A/ Yamagata/32/89 (H1N1), A/Uhan/359/95 (H3N2), and B/Mie/1/93 were significantly elevated by either doses. The pre-/post-vaccination mean HI of H1N1 were 61.5/668.4 with one dose, and 85.7/637.3 with two doses. The percent > x 128 were 36.5/96.2 with one dose, and 47.4/94.7 with two doses. No significant differences were apparent between one and two doses. Similarly, nonsignificant differences were observed for the other two antigens contained in the vaccine. We observed the sufficient immune response to only one dose of inactivated influenza vaccine, which emphasizes the merit of one dose method of influenza immunization.

Administration, Oral↗
PubMed1998

[Impact of influenza A virus infection as a cause of pediatric hospitalization and use of rapid antigen test of influenza A virus].

From the winter of 1997 to the spring of 1988, a severe epidemic caused by influenza A (H3N2) developed in Japan. During the epidemic (December 1997 to February 1998), 239 children were admitted to the pediatric ward of Nippon Kokan Hospital: as many as 76 (31.8%) were hospitalized with influenza A (H3N2) infection. Most were young healthy children (mean age, 3.7 years), suggesting the need of influenza immunization for this age group. 110 specimens of hospitalized children were examined by rapid antigen test of influenza A virus (Directigen Flu A, Becton Dickinson, USA). The rapid test showed about 90% sensitivity and specificity, as compared with isolation and serum hemagglutination inhibition test. Directigen Flu A proved to be a reliable, rapid screen for influenza A from symptomatic patients.

Adolescent↗
PubMed1998

A mesenteric liposarcoma with production of granulocyte colony-stimulating factor.

A 77-year-old female was admitted to our hospital because of pyrexia and a right retroperitoneal mass. Leukocytosis and other inflammatory findings were noted. Bone-marrow aspiration revealed hypercellularity with no malignant cells. An additional mass was detected sonographically in the pelvis. The serum concentration of granulocyte colony-stimulating factor (G-CSF) was highly elevated (299 pg/ml). The tumors were removed at laparotomy, and the pelvic mass was found to arise from the ileocecal mesentery. Postoperatively, white blood cell count and serum G-CSF concentrations decreased to normal levels. The mesenteric tumor showed weakly positive immunostaining for human G-CSF, and Northern and polymerase chain reaction (PCR) analyses detected CSF and its mRNA in the mesenteric tumor.

Aged↗
PubMed1998

Peripheral blood T cells and monocytes and B cell lines derived from patients with lupus express estrogen receptor transcripts similar to those of normal cells.

OBJECTIVE: To identify and characterize estrogen receptor (ER) transcripts expressed in immune cells of patients with systemic lupus erythematosus (SLE) and healthy donors. METHODS: Peripheral blood monocytes and T cells were prepared from patients with SLE (n = 6) and healthy donors (n = 8). T cells were separated into CD4 and CD8. Some monocytes and T cells were stimulated with estradiol, PMA, and ionomycin. Epstein-Barr virus-transformed B cell lines (n = 7) and B cell hybridomas (n = 2) established from patients with SLE and a healthy individual were used as a B cell source. These cells were examined for ER mRNA by reverse transcription nested polymerase chain reaction. Amplified cDNA were sequenced by standard methods. RESULTS: In all cells tested, ER mRNA was expressed without prior in vitro stimulation. Partial sequences from exons 1-8 were nearly identical to the published sequence of the human ER mRNA. There were no notable differences in the ER transcripts between patients and healthy controls. Variant receptor transcripts lacking exon 5 or exon 7, which encodes the hormone binding domain, were identified in the majority of the cells. Precise deletion of the exons suggests that they are alternatively spliced transcripts. Whether the detected transcripts are translated into functional receptor proteins remains to be determined. In vitro stimulation did not affect ER mRNA expression. The presence of variants did not correlate with disease activity or medication. CONCLUSION: Monocytes, T cells, and B cells in patients express transcripts of the normal wild type ER and the hormone binding domain variants in vivo.

Adult↗
PubMed1997

Characterization of monoglucuronides of vitamin D2 and 25-hydroxyvitamin D2 in rat bile using high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

The characterization of vitamin D2 3-glucuronide, 25-hydroxyvitamin D2 3-glucuronide and 25-hydroxyvitamin D2 25-glucuronide, biliary metabolites obtained from rats dosed with vitamin D2 and 25-hydroxyvitamin D2 per os, was carried out using HPLC-atmospheric pressure chemical ionization (APCI)-MS. The glucuronide obtained from bile specimens was identified by comparison of its chromatographic behaviour with an authentic sample using HPLC-APCI-MS operating in the negative-ion mode. Methylation of the respective fraction with diazomethane gave the methyl ester, which was also confirmed by HPLC-APCI-MS operating in the positive-ion mode. The (M-H)- and (M + NH4)+ ions were monitored in the selected-ion monitoring mode.

25-Hydroxyvitamin D 2↗
PubMed1997

Determination of 25-hydroxyvitamin D3 in human plasma by reversed-phase high-performance liquid chromatography with ultraviolet detection.

A method for the determination of 25-hydroxyvitamin D3, the major metabolite of vitamin D3 in human plasma, using a non-radioactive internal standard and reversed-phase high-performance liquid chromatography with UV detection (265 nm) has been developed. The method was applied to the determination of the metabolite in plasma from healthy subjects (n = 25) and from patients with chronic renal failure (n = 12). 25-Hydroxyvitamin D3 3-sulfate, a major conjugated metabolite of 25-hydroxyvitamin D3, was also determined and the correlation between the concentrations of these metabolites was examined. The study showed that almost equal amounts of both compounds were detected in the plasma of healthy subjects, however, in two subjects, the amount of sulfate in the free form was found to be about twice as high as normally detected. In contrast, the free form was predominant in the plasma of patients with chronic renal failure and the sulfate was not detected in four patients.

Calcifediol↗
PubMed1997

Genomic structure and promoter analysis of the gene encoding MM3, a member of transmembrane 4 superfamily.

We have isolated genomic clones encoding hamster MM3, a member of transmembrane 4 superfamily (TM4SF). Nucleotide (nt) sequence analysis revealed that it is composed of 5 exons spanning about 8 kb. The exon-intron organization of the MM3 gene was quite different from those of other TM4SF members. We also identified its transcription start points (tsp) and the promoter region. Deletion analysis of the promoter revealed that about 160-bp region containing TATA-box, CAAT-box and GC-box was necessary for efficient transcription in cultured cells.

Amino Acid Sequence↗
PubMed1997

Cytotoxic T lymphocyte response and viral load in hepatitis C virus infection.

A cytotoxic T lymphocyte (CTL) response to the hepatitis C virus (HCV) nucleoprotein residues 88-96 that are the minimal and optimal epitope for human leukocyte antigen (HLA) B44-restricted CTLs was assessed in 27 HLA B44-positive patients with chronic HCV infection. Serum HCV RNA concentration and the amino acid sequence of the residues 81-100 were also determined. Three patients were infected with HCV with uncommon amino acid substitutions within the epitope. One was infected with HCV with an amino acid substitution in the flanking residues of the epitope. To stimulate CTLs in the peripheral blood, 9-mer peptides that corresponded to the residues 88-96 of the individual patients were synthesized and used. Seven of the 27 patients demonstrated a CTL response to the residues 88-96 with specific cytotoxic activities higher than 20%. The CTL activities were significantly higher in patients with a low titer of serum HCV RNA than in those with a high titer of serum HCV RNA (P = .0006). Some of the patients that demonstrated a CTL response to the residues 88-96 also demonstrated a CTL response to a newly identified HLA B44-restricted CTL epitope or a known HLA A11-restricted CTL epitope or both. No apparent association was observed between the CTL response and the stage of disease, or between the CTL response and the grade of necroinflammatory activity. The results suggest that the HLA B44-restricted CTLs together with other HCV-specific CTLs may inhibit the outgrowth of HCV and that high-titer infection with HCV may suppress the CTL responses.

Adult↗