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Biomedical subjects

H Asakawa

Publications and source records attributed to H Asakawa.

At least 55 records · Page 3Linked to original sources
PubMed1995

Superficial esophageal cancer: multicenter analysis of results of definitive radiation therapy in Japan.

PURPOSE: To assess the effectiveness of definitive radiation therapy in patients with superficial esophageal cancer. MATERIALS AND METHODS: Method of irradiation, local control rate, survival rate, and complications were assessed in 105 patients (89 men, 16 women; age range, 50-88 years) with superficial esophageal cancer treated with definitive radiation therapy at 15 hospitals in 1981-1990. RESULTS: All lesions were confirmed to be squamous cell carcinoma. The overall 5-year survival rate was 38.7%; the 5-year disease-specific survival rate was 71.0%. The 2-year local control rate was 83.0%. Late complications occurred in 16 patients. The prevalence of complications was relatively high in the group treated with intraluminal radiation therapy. CONCLUSION: Local control and survival rates in patients treated with radiation therapy were excellent, especially in the group treated with external and intraluminal radiation therapy; however, the optimal dose and optimal combination of external and intraluminal radiation therapy should be further assessed.

Aged↗
PubMed1995

Stability, specific binding activity, and plasma concentration in mice of an oligodeoxynucleotide modified at 5'-terminal with poly(ethylene glycol).

Oligodeoxynucleotide (ODN) composed of 15 nucleotides was modified at 5'-terminal phosphate with hexylamine linker and chemically activated poly(ethylene glycol). This derivative showed improved characteristics in terms of enzymatic stability, binding activity, and in vivo retention in mouse. The data are discussed in comparison with those of corresponding unmodified and phosphorothioate ODNs.

Animals↗
PubMed1995

Malignant intestinal schwannoma: a case report and a review of the literature in Japan.

We report the rare case of malignant intestinal schwannoma, not accompanied with von Recklinghausen's disease. The main tumor was located in the ileum with multiple small tumors observed on the peritoneum. Histologically the tumor was composed of spindle cells exhibiting a nuclear palisading formation and abnormal mitotic figures were observed. The tumor was immunohistochemically positive for S-100 protein, glial fibrillary acidic protein, vimentin and neuron-specific enolase, but negative for desmin. Electron microscopically the tumor cell exhibited morphological findings characteristic of schwann cell differentiation. On the basis of these results, the tumor was diagnosed as malignant schwannoma occurring in the ileum.

Aged↗
PubMed1994

[Clinical experiences of granulocyte colony stimulating factor for granulocytopenia after AC bypass].

We have successfully treated 3 cases of granulocytopenia, using Granulocyte Colony Stimulating Factor (G-CSF) after AC bypass surgery. All cases were male, aged 68, 75 & 54 years old, and underwent AC bypass surgery without transfusion except in case 1. Granulocyte cell counts decreased to 135/mm3 on 39th post-operative days (POD) in case 1, 624/mm3 on 13 rd POD in case 2, and 514/mm3 on 20th POD in case 3. In case 1, 300 micrograms of G-CSF was given intravenously for 3 days. In case 2, 100 micrograms of G-CSF for 1 day and 50 micrograms for 3 days was given subcutaneously, and in case 3, 100 micrograms of G-CSF was also given subcutaneously for 2 days. And their granulocyte cell counts all increased within few days. G-CSF is effective for patients with granulocytopenia after AC bypass surgery, but we need more experiences to know the best way of administration.

Aged↗
PubMed1994

[Thyroid peroxidase (TPO) gene and pathogenic TPO mutation].

TPO is the key enzyme involved in the thyroid hormone synthesis. The human TPO (hTPO) gene locates on chromosome 2 and consists of 17 exons and 16 introns. Compared with other peroxidases, hTPO is 42% homologous with granulocyte myeloperoxidase. Thyroid cells contain multiple TPO mRNA transcripts of various size. However, the reason is unknown. TTF-1 and TTF-2 are known to regulate TPO gene expression. Moreover, the other factors are becoming clear to regulate it. Congenital TPO defects result in hypothyroidism and goiter. Recent studies clarify a human mutation causing TPO deficiency.

Amino Acid Sequence↗
PubMed1993

Establishment of a human anaplastic thyroid cancer cell line secreting granulocyte colony-stimulating factor in response to cytokines.

A human anaplastic thyroid cancer cell line K-119, derived from a 77-yr-old woman who had developed marked neutrophilia and underwent surgery for anaplastic thyroid cancer, has been established. The spindlelike and polygonal cells in shape are stably proliferating since the beginning of its culture 2 yr ago. The cells grow rapidly and the population doubling time is 26 h. The chromosomes show many abnormalities and many marker chromosomes have been observed. Heterotransplantation of the cells into nude mice has resulted in the formation of tumors that are histologically interpreted as anaplastic cancer. The most noteworthy characteristics of the cell line are the many Ki-67-positive cells (86.3%) and that the cell line spontaneously secretes granulocyte colony-stimulating factor (G-CSF) and releases increased amounts of G-CSF in response to the stimulation of tumor necrosis factor, interleukin 1 alpha, and interleukin 1 beta. The conditioned medium obtained from K-119 cells contains an autocrine factor stimulating the proliferation of themselves.

Aged↗
PubMed1993

[Antinuclear antibodies detected in autoimmune diseases].

In 1948, Hargraves discovered LE cells in the bone marrow and peripheral blood of a patient with systemic lupus erythematodes (SLE). Since then, the usefulness of the cell in the diagnosis of SLE has not changed. LE factor, a component of LE cell, is an anti-nuclear antibody. To date, many kinds of anti-nuclear antibodies have been discovered. Among others anti-dsDNA, anti-Sm and anti-ribosome antibodies were detected at a high rate and/or specifically in SLE. Therefore, they are used as markers for SLE. Recently, the antigen corresponding to each auto-antibody and the gene coding for it were clarified. In this paper, we describe methods for detecting anti-nuclear antibodies and LE cells, the significance of each auto-antibody in the diagnosis of auto-immune diseases, especially SLE and the relation between autoantibodies and symptoms in patients with the antibodies.

Antibodies, Antinuclear↗
PubMed1992

Function of DR-positive thyrocytes from patients with Graves' disease: quantitative analysis of thyroid peroxidase content by fluorescent photometry.

A considerable number of thyrocytes in patients with autoimmune thyroiditis ectopically express HLA-DR antigen. Furthermore, it has been reported that interferon-gamma-induced DR-positive thyrocytes in vitro secrete less thyroid hormone in response to TSH stimulation compared with DR-negative ones. However, the function of the intrinsically DR-positive thyrocytes is unknown. To evaluate their function, we stained by immunofluorescence for both DR antigen and thyroid peroxidase (TPO) in thyroid epithelial cells from patients with Graves' disease. We also measured the quantity of DR antigen and TPO using fluorescent photometry. The content of TPO was not significantly reduced in DR-positive thyrocytes compared with that in DR-negative thyrocytes. The TPO content is one measure of thyrocyte function. There was no significant difference between DR-positive and DR-negative thyrocytes. In conclusion, the function of DR-positive thyrocytes in vivo was not suppressed compared with that of DR-negative thyrocytes.

Adult↗
PubMed1992

Interferon-gamma reduces the thyroid peroxidase content of cultured human thyrocytes and inhibits its increase induced by thyrotropin.

To clarify the role of interferon-gamma (IFN gamma) in autoimmune thyroid diseases, we investigated the effects of IFN gamma on the content of thyroid peroxidase (TPO) and the expression of HLA-DR antigens in cultured normal human thyrocytes. The effect of TSH on the action of IFN gamma was investigated. Immunofluorescence staining and photometric analysis showed that IFN gamma not only induced the expression of DR antigen, but also reduced the content of TPO in a concentration-dependent manner. The addition of TSH increased the content of TPO and enhanced the IFN gamma-induced expression of DR antigen. IFN gamma also inhibited the increase in TPO content induced by TSH. Thus, complex interactions appear to exist between IFN gamma and TSH or thyroid-stimulating antibodies in the modulation of hormone secretion and autoimmune phenomena in the thyroid.

Adenoma↗
PubMed1992

Histamine release and SOD, allopurinol and ranitidine pretreatment in haemorrhagic shock in the rat.

Histamine release have been demonstrated in haemorrhagic shock. There are some observations that oxygen free radicals can cause histamine release. Oxygen free radicals play a role in the pathogenesis of gastric mucosal lesions. The goal of this study was to determine whether ranitidine or SOD and allopurinol pretreatment modify the histamine release during and after the haemorrhagic shock in the rat. In the anaesthetized rat 0.1 N HCl was instilled into the stomach and the rat was bled to reduce the blood pressure to 30 mmHg for 20 min. The shed blood was reinfused. Twenty min later the stomach was removed. The area of gastric mucosal lesions were measured, histological grading was made. Blood samples taken from the carotid artery were examined by radioimmunoassay (IMMUNOTECH) to determine the plasma histamine level. Plasma histamine level did not change significantly during the preparative surgery, but there was a significant increase of histamine level by the end of shock period. After the reinfusion of the blood the plasma histamine remained essentially at the same level for five min. Oxygen free radicals did not cause an important histamine release. By the end of the experiment the histamine level decreased dramatically. Ranitidine, allopurinol and SOD pretreatment provided significant protection against the gastric mucosal lesions. Allopurinol and SOD did not influence significantly the histamine level. Ranitidine caused significant histamine release immediately after the injection and every histamine value was significantly higher in this group except for the final value which was lower than the control one. The oxygen free radicals were not found as endogenous histamine releasers in this study.

Allopurinol↗
PubMed1992

Cell-to-cell communication in cultured rat thyroid monolayer cells is inhibited dose-dependently by methimazole.

We performed monolayer culture of rat thyrocytes and studied gap junctional communication by measuring intercellular fluorescence redistribution after photobleaching. Cell-to-cell communication among thyrocytes gradually developed during the culture. This communication was demonstrated in approximately 60 percent of the cells cultured for 8 days, while it could not be detected in the remaining 40 percent of the cells even after longer culture. When thyrocytes were cultured in the presence of methimazole, the fluorescence recovery after photobleaching was inhibited dose-dependently. Thyroid-stimulating hormone did not affect the fluorescence recovery. We provided, for the first time, that methimazole inhibited the development of cell-to-cell communication of thyrocytes dose-dependently.

Animals↗
PubMed1991

Interferon-gamma inhibits thyroid-stimulating hormone-induced morphological changes and induces the expression of major histocompatibility complex class II antigen in thyroid follicles in suspension culture.

The effects of interferon-gamma (IFN gamma) on the morphology of thyroid follicles and the expression of major histocompatibility complex (MHC) class II antigens were examined. The thyroid follicles were suspended in RPMI-1640 containing 10% fetal calf serum with or without IFN gamma (200 U/ml). After culture for 5 days, follicles were incubated in the presence of TSH (10 mU/ml) for 1 h and fixed for electron microscopic and immunohistochemical examination. Regardless of the presence of IFN gamma, suspended follicles became inverted within 5 days. However, MHC class II antigens were expressed only in inverted follicles cultured with IFN gamma. In inverted follicles cultured without IFN gamma, TSH stimulation induced remarkable morphological changes, such as elongation of microvilli and an appearance of pseudopods. On the other hand, the follicles cultured with IFN gamma showed poor response to TSH. Thus, IFN gamma induced the expression of MHC class II antigens of cultured thyroid follicles and inhibited TSH-induced morphological changes in the cells.

Animals↗
PubMed1991

Human recombinant interleukin 1 inhibits TSH-stimulated morphological changes in thyroid follicles cultured as semi-organs.

To study the effects of human recombinant interleukin-1 on thyrocytes, we cultured thyroid follicles as semi-organs, each consisting of approximately 10-20 follicles, in the presence or absence of IL-1 alpha or beta. Semi-organ culture reproduces the in vivo environment well. After culture for 2 or 4 days, the follicles were incubated with TSH (10 U/l) for 4 h and fixed for light and electron microscopical examinations. Regardless of the presence or absence of IL-1, follicular structure, polarity, and luminal colloid did not change during culture. In thyroid epithelial cells cultured without IL-1, TSH markedly induced elongation of microvilli and formation of reabsorbed colloid droplets. On the other hand, both IL-1 alpha and beta inhibited these TSH-stimulated changes. The degree of inhibition correlated with the concentration of exposure to IL-1. We conclude that IL-1 inhibits TSH-stimulated morphological changes in thyroid follicles cultured as semi-organs, depending on the concentration of IL-1.

Animals↗
PubMed1990

Microcalorimetric studies on metabolism of hepatic tissue. I. A methodological study of normal tissue.

In the present study, the heat production of liver biopsies (5-8 mg) was measured by a microcalorimetric technique. Tissue incubated in Leibowitz L-15 medium (L-15) showed a higher metabolic rate compared to tissue incubated in a medium without substrate 2.8 microW/mg and 1.75 microW/mg, respectively. Heat production was found to be related to weight density. No difference in the metabolic rate was found after organ perfusion in comparison to nonperfused liver. Storage in medium L-15 at 4 degrees C caused a lower rate of heat production, but if the tissue was stored in an electrolyte balance solution without substrate, no difference was seen compared to fresh tissue. Recording heat production with the present calorimetric technique is relatively simple and rapid and allows measurement of small samples.

Animals↗
PubMed1990

Microcalorimetric studies on metabolism of hepatic tissue. II. Measurements of ischemic tissue.

Biopsies of ischemic livers demonstrated a significantly higher rate of heat production when incubated in Leibowitz L-15 medium compared to incubation in modified Eagle's solution (P less than 0.01). A maximal reduction of 25% in the rate of heat production was observed after 60 min of induced ischemia. Liver tissue undergoing reperfusion showed complete and partial recovery after 60 and 90 min, respectively. We conclude that the viability of liver tissue begins to deteriorate after 1-1.5 h of ischemia. Using the level of adenosine triphosphate (ATP) as a parameter for viability, others had found this critical time period to be 1.5-2 h. Furthermore, we conclude that monitoring heat production of tissue provides a useful measure of viability for both clinical application and in connection with experimental liver surgery.

Adenosine Triphosphate↗
PubMed1990

Intranasal immunization of mice with recombinant protein antigen of serotype c Streptococcus mutans and cholera toxin B subunit.

The cholera toxin subunit and the recombinant cell-surface antigen (molecular mass of 190,000 Da) were administered intranasally to BALB/c mice. After 30 days, the mice were immunized intranasally with the recombinant protein antigen alone. High serum IgG and salivary IgA responses to the protein antigen were induced by the intranasal immunization.

Administration, Intranasal↗
PubMed1990

Surface hydrophobicity, adherence, and aggregation of cell surface protein antigen mutants of Streptococcus mutans serotype c.

The pac gene of the serotype c strain Streptococcus mutans MT8148 encodes a cell surface protein antigen (PAc) of approximate 190 kilodaltons. The serotype c strain S. mutans GS-5 does not produce the 190-kilodalton PAc but produces a lower-molecular-weight protein that reacts with anti-PAc serum. The SphI-BamHI fragment of the pac gene was ligated with the S. mutans-Escherichia coli shuttle vector pSA3. The chimeric shuttle vector was transformed into strain GS-5, and two transformants (TK15 and TK18) were isolated. These transformants produced a large amount of cell-free and cell-bound PAc of 190 kilodaltons. No plasmid was isolated from these transformants, and the EcoRI fragments of their chromosomal DNA hybridized with the erythromycin resistance gene in the shuttle vector DNA, indicating insertion of the chimeric shuttle vector DNA into the chromosomal DNA. The cell hydrophobicity of strains TK15 and TK18 as well as PAc-defective mutants constructed by inserting an erythromycin resistance gene into the pac gene of strain MT8148 was analyzed. Strains MT8148, TK15, and TK18 were hydrophobic. On the other hand, strain GS-5 and PAc-defective MT8148 transformants were hydrophilic. Resting cells of the hydrophobic strains attached in larger numbers to saliva-coated hydroxyapatite than did the hydrophilic strains. Human whole saliva induced the aggregation of cells of the hydrophobic strains but not that of cells of the hydrophilic strains. These results suggest that cell surface PAc of S. mutans serotype c participates in attachment of the streptococcal cell to experimental pellicles.

Antigens, Bacterial↗