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Biomedical subjects

Y Maeda

Publications and source records attributed to Y Maeda.

At least 703 records · Page 39Linked to original sources
PubMed1991

Regulatory mechanisms for the expression of a functional beta chain of interleukin 2 receptor on T4 chronic lymphocytic leukemia cells.

Monoclonal antibodies, each recognizing interleukin 2 receptor (IL-2R) alpha, or beta, were used to see the regulatory mechanisms of the expressions on leukemic cells from a patient with T4 chronic lymphocytic leukemia (T4-CLL). Cells from this patient expressed only IL-2R beta, and the expression was enhanced by medium cultivation. IL-1 enhanced the expression of not only IL-2R beta but also IL-2R alpha on the cells. Binding studies using 125I-IL-2 showed the presence of an intermediate receptor (734 sites/cell, Kd = 1.2 nM) and a few high-affinity receptor (172 sites/cell, Kd = 132 pM) on cells cultured with IL-1. IL-2 and IL-1 synergistically promoted the proliferation of the cells, suggesting that the induced IL-2R was functional. In addition, anti-IL-1 antibodies inhibited IL-2R beta expression by cultured cells, suggesting that it was dependent on IL-1 produced by the leukemic cells. These findings suggested that IL-1 might enhance the expression of IL-2R beta in a subset of human T cells, and implied a role of IL-1 in the proliferation of the leukemic T cells.

Aged↗
PubMed1991

[A case of adult Wilms' tumor--review of the literature on histopathological features and prognosis].

A case of Wilms' tumor in a 57-year-old woman is reported. She was with a complaint of a palpable mass on the right upper abdomen. CT scan showed a non-hemogenous mass arising from the lower pole of the right kidney. After transarterial embolization, right transabdominal radical nephrectomy was performed under the diagnosis of renal cancer. Histopathological study revealed Wilms' tumor stage 2. Over the two years after surgery the patient is disease-free. Wilms' tumor is rare in adults. The prognosis of adult Wilms' tumor is recognized to be poorer than that of children. Recently, Wilms' tumors in children are classified into two histopathological groups, that is "favorable histology" and "unfavorable histology" according to the cell differentiation. Based on a collection of the previous Japanese and English reports, we analyzed the relationship between the histopathological features and the prognosis in adult Wilms' tumor. Ten cases of unfavorable histology have very poor prognosis, with the two year survival rate of 22%. In contrast, that of 24 cases of favorable histology was 71%. In particular, all cases of the epithelial predominant type presenting favorable histology, including stag 4 cases, survived over two years. Our case was the epithelial predominent type presenting favorable histology. That is probably one of the chief reasons of the good prognosis. In conclusion, the above-mentioned results show that in adult Wilms' tumor, the prognosis of unfavorable histology is very poor, but that of a low stage or the epithelial type presenting favorable histology is, as in children, relatively good.

Aged↗
PubMed1991

Cloning, sequencing, and characterization of the intracellular invertase gene from Zymomonas mobilis.

The structural gene for the intracellular invertase E1 of Zymomonas mobilis strain Z6C was cloned in a 2.25-kb DNA fragment on pUSH11, and expressed in Escherichia coli HB101. The enzyme produced by the E. coli carrying pUSH11 was purified about 1,122 fold to homogenicity with a yield of 4%. The molecular weight and substrate specificity of the enzyme were identical with those of the intracellular invertase E1 from Z. mobilis. The nucleotides of the cloned DNA were sequenced; they included an open reading frame of 1,536 bp, coding for a protein with a molecular weight of 58,728. The N-terminal amino acid sequence predicted was identical with the sequence of the first 20 N-terminal amino acid residues of the protein obtained by Edman degradation. Comparison of the predicted amino acid sequence of E1 protein with those of the four other known beta-D-fructofuranosidases from Escherichia coli, Bacillus subtilis, and Saccharomyces cerevisiae indicated a stronger homology in the N-terminal portion than in the C-terminal portion.

Amino Acid Sequence↗
PubMed1991

[The diagnostic value of a new whole blood histamine release test using paper disc-coupled antigens--results compared with intracutaneous test, RAST, and eye test].

We have developed a novel histamine release test (HR) using whole blood and antigen-coupled RAST paper discs, for the screening of allergens rather in a short time with a small amount of blood. Histamine was determined by a RIA kit. In order to evaluate the diagnostic value, the results of the test were compared with those of RAST, intracutaneous tests, and eye tests in 45 allergic patients. HR correlates better with RAST than intracutaneous test in almost all antigens. The closest positive correlation with the other tests was seen in mite allergen, followed by pollen, foods and mould spores in that order. When the HR was positive for house dust, 100% of the patients were also positive for the eye test, which is reported to closely correlate with bronchial provocation tests. HR seemed to be a useful test not only for the screening but also for the determination of pathogenic allergens.

Adolescent↗
PubMed1991

Hepatitis C virus is a more likely cause of chronic liver disease in the Japanese population than hepatitis B virus.

508 Japanese patients with chronic liver disease, including chronic hepatitis, cirrhosis and hepatocellular carcinoma, and 500 controls matched for sex and age were studied. Antibody to hepatitis C virus (anti-HCV) alone was found in 233 (45.9%) patients and hepatitis B surface antigen (HBsAg) alone was present in 128 (25.2%) patients. Both anti-HCV and HBsAg were present in 18 (3.5%) patients. Anti-HCV was found in 8 (1.6%) controls and HBsAg was present in 4 (0.8%) controls. The prevalence of anti-HCV alone was 36.9% in chronic hepatitis, 49.0% in cirrhosis and 67.0% in hepatocellular carcinoma, respectively. The prevalence of anti-HCV increased with the progress of severity of liver disease. Anti-HCV was more prevalent than HBsAg both in cirrhosis and hepatocellular carcinoma (p less than 0.001). The prevalence of anti-HCV increased with age. Among patients under age 39 years, HBsAg was detected more often than anti-HCV, however, in those over age 50 years, anti-HCV was detected more often than HBsAg (p less than 0.001). It would appear that hepatitis C virus more than hepatitis B virus is a prominent cause of chronic liver disease among Japanese patients.

Adolescent↗
PubMed1991

Role of PAF and cytokines in the modulation of Fc epsilon RII/CD23 expression on human eosinophils.

IL-4 and gamma IFN profoundly modulate the expression of the cell surface and soluble Fc epsilon RII/CD23 molecule, which is a low affinity Fc receptor for IgE having regulatory activity on immune system. IL-4 is a general inducer of Fc epsilon RII/CD23 on B lymphocyte, monocyte/macrophage, and eosinophil lineages, while gamma IFN counteracts the enhancing effect of IL-4 on normal B lymphocytes. However, the effect of gamma IFN is more complex than that of IL-4. gamma IFN up-regulates those on monoblast cell line U937 and eosinophil cell line EoL. This differential regulation of Fc epsilon RII/CD23 on B cells and the other cell types may play important roles in immune system, as macrophages and eosinophils are critical cells in the allergic reactions. In addition to cytokines, we found that platelet activation factor (PAF) up-regulates the expression of Fc epsilon RII/CD23, whereas transforming growth factor-beta (TGF-beta) and glucocorticosteroid (dexamethasone) down-regulate it on U937 and EOL cells. Variable and strong effect of these factors on the expression of CD23/Fc epsilon RII may indicate the involvement of this receptor system in the allergic as well as immune reactions and possibly the pathophysiology of the allergic and immunological disorders.

Antigens, CD↗
PubMed1991

[Choroidal detachment associated with spontaneous carotid cavernous fistula].

A rare case is presented in which an 87-year-old woman with choroidal detachment was subsequently found to have an atypical carotid cavernous fistula (CCF). In this case, the intraocular pressure of the affected eye was higher than that of the contralateral eye. However, tonography showed no increased ocular pulse (amplitude of Schioetz reading) of the affected eye, which is characteristic of CCF. Choroidal detachment accompanied with CCF is thought to be a result of severe choroidal hemostasis and transudation caused by increased episcleral venous pressure. Furthermore, the enlarged perichoroidal space due to choroidal detachment reduced the ocular pulse of the affected eye. This combination may not be as rare as it has been previously reported. Attention to these symptoms can provide clues to the elucidation of the pathogenesis of choroidal detachment.

Aged↗
PubMed1991

[Plasma PAI-1 levels in patients with various tumors with or without metastasis].

Recently, much interest has focussed on fibrinolysis in malignant tumors. In our previous study, we showed that t-PA antigen was significantly increased in plasma from patients with malignant tumors with metastasis. In our present study, we measured plasminogen activator inhibitor-1 (PAI-1) levels in plasmas from patients with various tumors. PAI-1 antigen was measured by means of enzyme immuno assay in plasma from 64 consecutive patients with a variety of malignant tumors. Patients were subdivided into two groups, one with (n = 47) and without (n = 17) metastasis. In the group with metastasis except for lung cancer, PAI-1 antigen level was increased compared to age-matched control subjects, while in the group without metastasis, PAI-1 antigen level was normal.

Adult↗
PubMed1991

[Two cases of TSH-secreting pituitary adenoma; endocrinological, diagnostic and therapeutic approach to the disease].

Two cases of TSH-secreting pituitary adenoma were reported. Endocrinological and immunohistochemical features of these cases were described and problems in diagnosis and treatment of the rare disease are discussed. [case 1] A 28 year-old woman suffered from hyperthyroidism with a relatively high value of serum TSH (T3; 350 ng/dl, T4; 10.0 micrograms/dl, TSH; 24.5 microU/ml). She was treated with antithyroid drug and then underwent subtotal thyroidectomy. Although the levels of serum T3 and T4 were lowered to within normal range, the level of serum TSH still remained high. One month later, she developed frontal headache, amenorrhea and bitemporal hemianopsia. A CT scan showed an enhanced mass in the sellar and suprasellar region. Preoperative endocrinological studies showed elevated values of TSH (47 microU/ml) and its alpha-subunit (9.0 ng/ml). The levels of both T3 (190 ng/dl) and T4 (10.0 micrograms/dl) were near the upper normal limit. Serum TSH was suppressed by administration of exogenous T3, but did not respond to exogenous TRH, l-Dopa nor bromocriptine. Under the diagnosis of TSH-secreting pituitary adenoma, the patient was operated on by craniotomy and received local radiation therapy (50 Gy). In 1990, 12 years after the treatment, she is well and endocrinologically normal. Immunohistochemical study revealed that most tumor cells were positive for TSH. [case 2] A 28 year-old woman visited our hospital for examination of hyperthyroidism. Serum level of TSH was detectable (4.5 microU/ml). A CT scan performed at that time disclosed no pituitary tumor. Thyroid function was normalized by antithyroid drug, but the level of TSH was still high and progressively increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1991

Immunological and virological status of a hemophiliac infected with human T cell lymphotropic virus type 1 and human immunodeficiency virus type 1, and results of therapy.

The immunological and virological status of three hemophiliacs infected with human immunodeficiency virus type 1 (HIV-1) was monitored for 11 months. One of these patients was also infected with human T cell lymphotropic virus type 1 (HTLV-1), and HIV-1 could be isolated only from this patient among the three subjects. The doubly infected subject had the fewest T4 (helper) lymphocytes and the highest proportion of T8 lymphocytes with DR human leukocyte antigens (DR-Ag). The serum level of HIV-1 antigen increased in this patient during the observation period, and this increase was accompanied by a decrease in the proportion of DR-Ag-positive cells among the T8 lymphocytes. This patient was treated with 800 mg of zidovudine daily for 50 days. With treatment, the nonspecific clinical symptoms improved and the proportions of DR-Ag positive cells among the T8 lymphocytes decreased. Serum levels of HIV-1 antigen decreased immediately when therapy was started but later increased during therapy. In persons infected with both HTLV-1 and HIV-1, HIV-1 seems to proliferate readily.

Adolescent↗
PubMed1991

[An enzyme-linked immunosorbent assay (ELISA) for the quantitation of sugi pollen and Dermatophagoides mite allergens and its application for standardization of allergen extracts].

A simple enzyme-linked immunosorbent assay (ELISA) has been developed for the quantitation of the major allergens of sugi pollen, Cry j I and of Dermatophagoides mites, Der I (Der p I/Der f I) and Der II (Der p II/Der f II) for use in the in vitro standardization of allergen extracts. Polystyrene microplates coated with a IgG fraction of rabbit antiserum were incubated first with allergen extracts and then with biotinylated antiserum IgG. The bound allergen-biotinylated antibody complex was detected with commercially available streptavidin-enzyme conjugate followed by the addition of colorimetric substrate. The assay was very sensitive (-0.2 ng/ml) and reproducible (CV% = 1.9-13.8%). The ELISA was compared with the radioimmunoassay previously described, and the results showed a very good correlation between the assays (r = 0.967-0.990). The allergen content in three sugi pollen and three house dust extracts measured by the ELISA also demonstrated a good agreement with the relative potency of these extracts as determined by the intradermal skin test. These results indicate that the ELISA could be useful in the standardization of allergen extracts.

Allergens↗
PubMed1991

Selective increase in cytochrome P450 content in hepatic microsomes from rats with ventromedial hypothalamic lesions.

Changes in the components of hepatic microsomal electron transport systems and in drug hydroxylase activities were investigated in ventromedial hypothalamus (VMH) lesioned obese rats. Eight weeks after electrolysis of the bilateral VMH, the content of cytochrome P450 per mg microsomal protein (0.79 +/- 0.07 nmol/mg protein) was significantly higher (P less than 0.02) than that in the sham-operated rats (0.59 +/- 0.02). Cytochrome P450 per whole liver in the VMH-lesioned obese rats had also significantly increased (87 +/- 9 nmol vs 56 +/- 3, P less than 0.02). No significant differences were found in the cytochrome b5 contents, and the activities of NADPH- and NADH-cytochrome c reductases between the VMH-lesioned obese and sham-operated rats. The demethylation activities of aminopyrine (1.04 +/- 0.02 nmol/mg protein/min vs 0.94 +/- 0.02, P less than 0.05) and p-nitroanisole (0.96 +/- 0.02 vs 0.89 +/- 0.02 , p less than 0.02) and the aniline hydroxylase activity (0.22 +/- 0.01 vs 0.16 +/- 0.01, P less than 0.01) were enhanced, but 7-ethoxycoumarin O-deethylase activity was unchanged in the VMH-lesioned obese rats. These results indicate a selective increase in the content of cytochrome P450 among the components of the P450-dependent mixed function oxidase system in the liver of VMH-lesioned obese rats. Our observations suggest that drug metabolism may be enhanced in the hypothalamic obesity.

Animals↗
PubMed1991

[Biomolecular aspects of adult T-cell leukemia].

ATL (adult T-cell leukemia) is the first human cancer known to be caused by a retrovirus. ATL cells show usually positive for CD2, CD3, CD4, CD25 and HLA-DR, but negative for CD8. They produce a variety of cytokines, including IL-1, IL-2, TNF, ADF and PTHrP. PTHrP is considered to be responsible for hypercalcemia which is frequently observed in ATL. Recently, we reported two unusual cases of HTLV-I associated malignancy; 1) a case of CD4 and 8 double negative tumor affecting mainly gastrointestinal tract and 2) a case mimicking small cell lung cancer. IL-2-toxin, a conjugate of IL-2 and diphtheria toxin, has been prepared as a recombinant product and evaluated for the suppressive effect to ATL cells. Clinical trail of IL-2-toxin is now anticipated.

Antigens, CD↗
PubMed1990

Detection of radial crossbridge force by lattice spacing changes in intact single muscle fibers.

Time-resolved lattice spacing changes were measured (10-millisecond time resolution) by x-ray diffraction of synchrotron radiation in single intact muscle fibers of the frog Rana temporaria undergoing electrically stimulated tension development during application of stretches and releases. Ramp releases, which decreased fiber length at constant speed, caused a lattice expansion. After the ramp, increasing tension during recovery was accompanied by lattice compression. Ramp stretches caused a compression of the lattice. While the fiber was held at a constant length after the stretch, tension decreased and lattice spacing increased. These observations demonstrate the existence of a previously undetected radial component of the force generated by a cycling crossbridge. At sarcomere lengths of 2.05 to 2.2 micrometers, the radial force compresses the myofilament lattice. Hence, the myofilament lattice does not maintain a constant volume during changes in force.

Animals↗
PubMed1990

Genetic changes and histopathological types in colorectal tumors from patients with familial adenomatous polyposis.

Loss of heterozygosity (LOH) and K-ras mutation were analyzed in 111 colorectal polyps and 26 invasive carcinomas from 40 patients with familial adenomatous polyposis of distinct histopathological types. LOH, being less than 2% in moderate adenomas, was detected on chromosome 5q (20%) in severe adenomas, on 5q (26%) and 17p (38%) in intramucosal carcinomas, and on 5q (52%), 17p (56%), 18 (46%), and 22q (33%) in invasive carcinomas. LOH on chromosome 5q occurred most frequently in the region close to the APC gene both in adenomas and carcinomas, and a loss of the normal allele of the APC gene was demonstrated in 3 cases. K-ras mutation markedly increased in the step of development from moderate (11%) to severe (36%) adenomas. These results suggest the following mechanisms for the development of colon tumors in patients with familial adenomatous polyposis: (a) the heterozygous mutant/wild-type condition at the APC gene causes formation of mild or moderate adenoma; (b) the loss of the normal allele in the APC gene leads to a change from moderate to severe adenoma; (c) LOH on chromosome 17p contributes to the conversion of adenoma to intramucosal carcinoma; (d) LOH on other chromosomes, such as 18 and 22q, are involved in the progression of intramucosal carcinoma to invasive carcinoma; and (e) K-ras mutation may also affect the development of moderate to severe adenoma.

Adenomatous Polyposis Coli↗