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Biomedical subjects

M Mayumi

Publications and source records attributed to M Mayumi.

At least 361 records · Page 20Linked to original sources

Immunoglobulin A antibody against hepatitis B core antigen of polymeric and monomeric forms, as well as of IgA1 and IgA2 subclasses, in acute and chronic infection with hepatitis B virus.

Solid-phase radioimmunoassays using monoclonal antibodies were used to assay antibody to hepatitis B core antigen of immunoglobulin A class in terms of polymeric and monomeric forms, as well as of IgA1 and IgA2 subclasses, in the serum of persons infected with hepatitis B virus. The level of secretory immunoglobulin A antibody was significantly higher in patients with acute hepatitis (mean +/- S.E., sample per normal ratio = 29.2 +/- 1.9) than that in asymptomatic carriers (2.1 +/- 0.1), patients with chronic persistent hepatitis (3.5 +/- 0.5), patients with chronic active hepatitis (6.9 +/- 1.3) or patients with cirrhosis (5.8 +/- 1.1). In acute type B hepatitis, only polymeric immunoglobulin A antibody of either IgA1 or IgA2 subclass was detected. In contrast, in chronic infection, antibody to hepatitis B core antigen of IgA2 subclass was found in the polymeric form, but antibody of IgA1 subclass was detected in both polymeric and monomeric forms.

Antibodies, Monoclonal↗

Antibodies to translation products of the pre-S1 and pre-S2 regions of the envelope gene of hepatitis B virus in fulminant hepatitis B.

Sera from 11 patients with fulminant hepatitis B were tested for antibodies to translation products of the pre-S1 and pre-S2 regions of hepatitis B virus of IgM, IgA and IgG classes, as well as of IgA1, IgA2 and SIgA, with solid-phase enzyme immunoassays using native viral polypeptides. Antibodies to pre-S1 region product of IgM and/or IgA class were detected invariably in six patients who still had detectable hepatitis B surface antigen in serum at the time of clinical presentation. The remaining five patients who had lost HBsAg at presentation had antibodies to pre-S region products of various immunoglobulin classes in higher titers. The five patients with fulminant hepatitis without HBsAg had higher levels of IgA antibodies to pre-S region products than the seven patients with nonfulminant acute hepatitis B who had lost HBsAg: IgA antibody to pre-S1 region product (75.6 +/- 63.8 vs. 2.9 +/- 3.2, p less than 0.01) and IgA antibody to pre-S2 region product (28.9 +/- 25.3 vs. 4.2 +/- 6.9, p less than 0.01). IgA antibodies to pre-S1 and pre-S2 region products were invariably polymeric in fulminant hepatitis B. These findings are compatible with the hypothesis that a heightened humoral antibody response to pre-S1 and pre-S2 region products occurs early during the course of fulminant hepatitis B, participating in severe hepatic injury and early clearance of virus characteristic of this disease.

Acute Disease↗

Induction of eosinophilic granules, nonspecific esterase activity and CD14 expression in the human eosinophilic leukemia cell line, EOL-1.

We examined the expression of eosinophilic granules, esterase activity and CD14 in a human eosinophilic cell line, EoL-1. Unstimulated EoL-1 cells were weakly positive for nonspecific esterase, but negative for surface CD14, and contained a few eosinophilic granule-positive cells. A combination of G-CSF and TNF-alpha increased the eosinophilic granule-containing cells, but failed to increase esterase activity or CD14 expression. IFN-gamma alone or in combination with TNF-alpha enhanced nonspecific esterase activity but failed to induce CD14 expression or increase eosinophilic granule-containing cells. dbcAMP increased eosinophilic granule-containing cells, nonspecific esterase activity and CD14 expression. Specific esterase activity was not detected in any circumstances. EoL-1 cells fractionated by density gradients or CD14 expression showed nonspecific esterase activity and CD14 expression in both the eosinophilic granule-positive and negative cell populations. Forskolin and butyrate had a synergistic effect on CD14 induction and protein kinase A was suggested to play a role in dbcAMP-induced CD14 expression. A protein kinase C activator, phorbol 12-myristate 13-acetate, did not increase eosinophilic granules, nonspecific esterase activity or CD14 expression in EoL-1 cells. The results show that EoL-1 cells can express nonspecific esterase and CD14, but the expression is not necessarily restricted to cells which have differentiated into the monocyte/macrophage lineage.

Antigens, CD↗

Prediction of the development of atopic symptoms in early childhood by cord IgE-binding factors (soluble Fc epsilon R2).

The relationship of cord serum sFc epsilon R2 levels to the development of atopic symptoms in early childhood was studied. Cord sFc epsilon R2 was 444.2 +/- 235.1 pg/ml (n = 77), which was not significantly different from maternal serum sFc epsilon R2 (541.7 +/- 346.9 pg/ml, n = 42). However, there was no correlation between cord and maternal serum sFc epsilon R2, suggesting that most, if not all, of cord serum sFc epsilon R2 was produced by the fetus itself. Cord serum sFc epsilon R2 in infants who developed atopic symptoms later was significantly higher than that in infants who were free of atopic symptoms (P less than 0.01 at 7 and 13 months of age). The incidence of the development of atopic symptoms increased with the increase of cord serum sFc epsilon R2. These results suggest that sFc epsilon R2 is related to the development of atopic disorders and that the measurement of cord serum sFc epsilon R2 may be of value in predicting the development of atopic disorders in early childhood.

Antibodies, Monoclonal↗

Selective absence of immunoglobulin A1 or A2 among blood donors and hospital patients.

A hemagglutination inhibition assay was developed for the determination of immunoglobulin A1 and A2 (IgA1 and IgA2) with subclass-specific rabbit antiserums. Among 93,020 apparently healthy blood donors, selective absence of IgA1 was found in six and that of IgA2 in 15, at a prevalence much higher than the absence of total IgA that was revealed by only one donor. Among 6800 hospital patients with various disorders, the absence of IgA1 was found in one with breast cancer and that of IgA2 in two with rheumatoid arthritis.

Adolescent↗

Infection with hepatitis delta and human immunodeficiency viruses among hemophiliacs in Japan.

Two hundred two patients with hemophilia, dependent solely on imported coagulation factor concentrates, were tested for markers of hepatitis B virus infection, antibody to hepatitis delta virus (anti-HD), and antibody to human immunodeficiency virus (anti-HIV). Nine carriers of hepatitis B surface antigen (HBsAg) were identified. Six (66.7%) of them were positive for anti-HD, a prevalence much higher than that in HBsAg carriers without hemophilia in Japan (1/113 or 0.9%, p less than 0.001). Anti-HIV was found in 96 (47.5%), in sharp contrast to the low prevalence (0/1205) in apparently healthy blood donors (p less than 0.001). These results implicated imported plasma products in the transmission of both delta and human immunodeficiency viruses to hemophiliacs. An efficient method for the sterilization of plasma products is warranted to prevent exposure of hemophiliacs to the accompanying pathogenic viruses.

Acquired Immunodeficiency Syndrome↗

Successful treatment of essential thrombocythemia evolving into agnogenic myeloid metaplasia with interferon-alpha.

PURPOSE: Essential thrombocythemia and agnogenic myeloid metaplasia as one form of idiopathic myelofibrosis are myeloproliferative disorders and are quite rare in children. A patient with essential thrombocythemia that transformed to "adult-type" agnogenic myeloid metaplasia is described. PATIENTS AND METHODS: A routine examination of an 8-year-old girl with bronchial asthma showed thrombocytosis. Essential thrombocythemia was diagnosed 2 years later. During a 3-year follow-up without treatment, transition of the essential thrombocythemia to agnogenic myeloid metaplasia was noticed. The patient had an excellent response to interferon (IFN)-alpha therapy. CONCLUSION: This case is unique because of the availability of premorbid hematologic data and the natural progression of essential thrombocythemia to agnogenic myeloid metaplasia. Whether IFN-alpha therapy can prevent the progression of idiopathic myelofibrosis to leukemia has not yet been determined.

Child↗

Serum soluble CD44 in pediatric patients with acute leukemia.

PURPOSE: CD44 is an adhesion molecule expressed on a variety of cells, and its level correlates with the metastatic potential of malignant tumors. Serum concentrations of soluble CD44 (sCD44) are elevated in various cancers. The purpose of this study was to measure the serum concentrations of CD44 in pediatric patients with acute leukemia. PATIENTS AND METHODS: Fourteen pediatric patients with acute leukemia were studied. The authors measured the serum concentration of sCD44 by enzyme-linked immunosorbent assay before and after therapy. The concentrations were compared with those of 15 control healthy children and 10 patients with bacterial infections. RESULTS: The mean serum concentration of sCD44 at presentation was significantly higher in patients than in control subjects, but decreased to a normal range in complete remission after chemotherapy. There was no difference in sCD44 concentrations between patients with acute lymphocytic leukemia and those with acute myeloid leukemia. Serum concentrations of sCD44 did not correlate with lactic dehydrogenase concentrations or bone marrow nucleated cell counts and only weakly with peripheral leukocyte count. sCD44 levels in patients with bacterial infections were similar to those of control subjects. CONCLUSION: Serum concentration of sCD44 may reflect disease status in pediatric patients with acute leukemia and might be a useful tumor marker in these patients.

Antibiotics, Antineoplastic↗

Defects in the precore region of hepatitis B virus DNA in a plasma pool from carriers seropositive for antibody against e antigen and with infectivity in chimpanzees.

A plasma pool from 12 asymptomatic carriers seropositive for antibody against hepatitis B e antigen (anti-HBe) contained hepatitis B virus (HBV) with chimpanzee infectious doses of 1-100/mL, and another pool from 12 carriers positive for hepatitis B e antigen (HBeAg) contained 10(8)/mL doses or more. The HBeAg-positive pool contained 10(6)-fold more HBV DNA than the anti-HBe-positive pool, reflecting the difference in infectivity in chimpanzees. The precore region sequences of HBV DNA in the two plasma pools were amplified by polymerase chain reaction, and separate HBV DNA clones were propagated for determining the nucleotide sequence. Of 114 clones from the anti-HBe-positive pool, 113 displayed a point mutation from guanine to adenine at nucleotide 83 in the precore region, which converted codon 28 for tryptophan (TGG) to a stop codon (TAG), and the remaining clone had a point mutation from adenine to cytosine at the first letter of codon 1 (CTG) to inhibit the translation initiation of the precore region. Precore region defects, in contrast, were observed in only 10 (8%) of 119 clones from the HBeAg-positive pool. These results indicate the infectious capacity of HBV mutants, defective in the precore region and incapable of directing the synthesis and secretion of HBeAg, which prevail in the circulation of hosts after they seroconvert from HBeAg to anti-HBe.

Amino Acid Sequence↗

Systemic inflammatory response syndrome and acute renal failure associated with Hemophilus influenzae septic meningitis.

Sepsis is often associated with a downward spiral through a spectrum of systemic inflammatory response syndrome (SIRS) culminating in organ failure and death. Here we present a 3-year-old girl with Hemophilus influenzae septic meningitis who developed SIRS and acute renal failure. In the initial stage, the patient showed uremia, cytopenia, disseminated intravascular coagulation, elevation of tissue enzyme and ferritin values, hemophagocytosis and overproduction of nitric oxide. The serum cytokine profile revealed increased levels of soluble interleukin (IL)-2 receptor, IL-6, IL-10 and tumor necrosis factor alpha. The patient responded positively to early and intensive interventions including antibiotics, repeated exchange transfusions, dexamethasone and high-dose gamma-globulin. The above laboratory abnormalities almost normalized with clinical improvement. We consider that SIRS was probably responsible for the sequence of events resulting in renal failure in this case, and suggest that renal failure should be included among the serious complications of SIRS associated with Hemophilus influenzae septic meningitis.

Acute Kidney Injury↗

Hepatitis C virus genotypes in the Islamic Republic of Iran: a preliminary study.

According to the divergent geographical distribution of the hepatitis C virus (HCV) and the fact that the virus possesses six major genotypes and more than 90 subtypes, we decided to determine the prevalence of the major HCV genotypes in the Islamic Republic of Iran. Serum samples from 21 HCV infected individuals were tested primarily by second generation of enzyme immunosorbent assay and the two-stage PCR method. For determining the five most common variants, second generation methods for genotype specification were used. The prevalence of specific genotypes in 15 samples is as follows: Type I/1a in seven cases, Type II/1b in three cases and Type V/3a in four patients. One sample disclosed Type 4.

Blood Donors↗