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Biomedical subjects

H Ota

Publications and source records attributed to H Ota.

303 records · Page 17Linked to original sources
PubMedDate not supplied

Prolongation of cardiac allograft survival by intraportal injection of donor antigens--differential mechanisms according to the timing of injection.

Recently, we reported that intraportal (IP) injection of donor spleen cells (SPCs) before transplantation as well as at the time of transplantation significantly prolongs cardiac allograft survival in rats (7). Long-term establishment of chimerism induced by intraportal administration of SPCs could be a part of this prolongation. In this study, we examined the effect of irradiation of SPCs as a source of donor antigens on cardiac allograft survival. Experiments were carried out using DA (RT1a) as the donor and BUF (RT1b) as the recipient strain. Fifty million irradiated or nonirradiated SPCs were injected either intravenously (i.v.) or intraportally (i.p.) on day -10 or day 0, the day of cardiac allografting. Untreated animals rejected allografts within a mean survival time (MST) of 7.2 +/- 0.8 days (n = 5). Injection (i.p.) of SPCs on both day -10 (n = 4) and day 0 (n = 6) induced significant prolongation of MST over the control (19.0 +/- 4.7, 14.2 +/- 2.1 days; p < 0.001 vs. control), while i.v. injection of SPCs on either day -10 (n = 4) or day 0 (n = 4) failed to do so (9.2 +/- 1.0, 8.5 +/- 0.6 days). Significant prolongation was still observed when irradiated SPCs were injected on day -10 (n = 4; MST: 19.0 +/- 5.4 days, p < 0.002 vs. control), but not when injected on day 0 (n = 5; MST: 9.4 +/- 2.1 days). These data suggest that the immunosuppressive effect of i.p. injection of donor SPCs could be induced by differential mechanisms according to the timing of inoculation of donor antigens.

Animals↗
PubMedDate not supplied

Histone H3 messenger RNA in situ hybridization for identifying proliferating cells in formalin-fixed rat gastric mucosa.

To devise a more sensitive method for identifying proliferative cells in routinely formalin-fixed, paraffin-embedded tissues, we applied an in situ hybridization (ISH) technique for the detection of histone H3 mRNA in rat gastric mucosa and amplified the signal by a silver intensification method. ISH was performed using a Fluorescein-labelled, single-stranded DNA probe for the human histone H3 gene. To determine the optimal conditions for detecting H3 mRNA in rat gastric mucosa, we tested the effect of changing conditions, such as fixation time and digestion time, by a proteinase before hybridization. Next, the proliferation indices obtained using H3 ISH were compared with those obtained using bromodeoxyuridine (BrdU) immunohistochemistry. In normal rat gastric mucosa, H3 ISH- and BrdU-positive cells were confined to the neck region of both fundic and pyloric mucosa. The two labelling indices were almost the same. In all the serial sections studied, H3 ISH-positive cells were almost always BrdU-positive too. Taken together, these results indicate that the H3 ISH technique is useful for the evaluation of proliferative activity in gastric epithelial cells by virtue of its detection of S-phase cells.

Animals↗
PubMedDate not supplied

Ultrastructural features of adenoma malignum of the uterine cervix: demonstration of gastric phenotypes.

Histochemical staining has shown that so-called adenoma malignum (the mucinous type of minimal deviation adenocarcinoma [mucinous MDA]) of the uterine cervix expresses gastric phenotypes. The present ultrastructural study was undertaken to explore the fine structure and phenotypic expression of this tumor, and to make comparisons with normal cervical glands and gastric pyloric mucosa. Post-embedding, double-immunogold staining for gastric gland mucous cell mucin (HIK1083-reactive mucin) and lysozyme revealed localization exclusively to the matrix and to the core of the mucin granules, respectively, both in mucinous MDA and gastric pyloric mucosa. Mucin granules of normal cervical gland cells lacked core structures and showed no immunoreactivity with HIK1083 or lysozyme. Thus, mucinous MDA was confirmed to be a tumor expressing gastric phenotypes ultrastructurally. Both markers should be useful for the identification of tumor cells.

Adenocarcinoma, Mucinous↗
PubMedDate not supplied

Is adenomyosis an immune disease?

Adenomyosis is characterized as ectopic endometrial tissues within the myometrium in the uterus. The only difference between adenomyosis and endometriosis is the site of endometriotic tissues: inside or outside of the uterus. It is well known that endometriosis is frequently associated with various autoimmune phenomena. This short review covers various aspects of the immune cascade found in adenomyosis. In adenomyosis, a series of immune responses is activated, including changes in both cellular and humoral immunity, i.e. a strong expression of cell surface antigens or adhesion molecules, an increased number of macrophages or immune cells, and deposition of immunoglobulins and complement components. Furthermore, the disease exhibited high frequency of autoantibodies in peripheral blood. Thus, an immunological 'vicious circle' is formed in the endometrium in adenomyosis. Endometrial cells seem to be under immunological stress, protecting themselves by exposing heat shock proteins. It is concluded that the endometrial environment in adenomyosis differs widely from that in normal fertile women. These abnormal immune responses might be involved in poor reproductive performance in adenomyosis.

Autoantibodies↗
PubMedDate not supplied

Traumatic atlantoaxial dislocation causing os odontoideum in infants.

The pathogenesis of os odontoideum is still a subject of debate. The authors encountered two infants who had traumatic atlantoaxial dislocation and in whom os odontoideum later developed. One of the infants died of tardive cervical myelopathy secondary to cord compression. The authors present their concept that postnatal development of this abnormality results from fracture of the odontoid.

Axis, Cervical Vertebra↗
PubMedDate not supplied

Microchimerism and hyporesponsiveness induced by intraportal injection of donor spleen cells in rats.

It is controversial whether or not microchimerism (MC) is responsible for the induction and maintenance of donor-specific tolerance. We have shown that intraportal injection (i.p.) of donor splenocytes induces a long-term graft survival of liver and heart in rats. In this study, we examined by polymerase chain reaction (PCR) the status of MC in the liver, spleen, and blood of rat cardiac recipients following i.p. or intravenous injection (i.v.) of donor splenocytes. Male DA (RT1a) and Wistar (RT1k) rats were used as donors and recipients, respectively. Heterotopic heart transplantation was performed 10 days after i.p. or i.v. injection of 5 x 10(7) DA spleen cells. DA cardiac allografts were rejected with a mean survival time (MST) of 11.9 +/- 1.6 (n = 10) days in nontreated recipients. Injections (i.v.) led to no significant prolongation of graft survival (MST: 11.2 +/- 1.9 days, n = 6), while i.p. or i.v. injection alone resulted in significant MC in these organs throughout the observation time over 60 days. MC was detected in the spleen, liver, and blood of cardiac recipients 7 days after transplantation and also even after cessation of cardiac heartbeat 21 days after transplantation. This was the case with either i.p. or i.v. group, which showed MC on day 7 after transplantation and persistent MC after cessation of the heartbeat. These data suggests that the presence of MC in the liver, spleen and blood of transplant recipients may not be responsible for immunological unresponsiveness to donor antigens.

Animals↗
PubMedDate not supplied

Retroperitoneal malignant fibrous histiocytoma surgically removed six times using a harmonic scalpel.

This paper describes a patient with retroperitoneal malignant fibrous histiocytoma who underwent surgical removal of the tumor 6 times. It is difficult to remove locally recurrent retroperitoneal malignant fibrous histiocytoma many times by repeat surgery, since the tumor tends to adhere tightly to the surrounding scar tissue. In the 5th and 6th operations we conducted on the patient, a harmonic scalpel was useful for separating the tumor from the scar tissue at the previous surgical site.

Cicatrix↗
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Distribution of TNF endogenously induced by various immunopotentiators and Lactobacillus casei in mice.

Intravenous administration of heat-killed Lactobacillus casei YIT 9018 (LC) elicited endogenous cytotoxic factor (CF) production in ICR mice, peaking in serum after 2 h and declining gradually to basal level at 23 h. The endogenous CF production was significantly enhanced by priming with high molecular-weight lignins and glucans, but not by phenylpropenoid precursors or partially hydrolyzed products of glucans. The extent of stimulation of CF production by these priming agents was positively related to that of tumor necrosis factor (TNF) production, as judged by enzyme-linked immunosorbent assay. Endogenously produced TNF was concentrated more in liver, lung and intestine, as well as in serum, than in other organs. Histochemical examination revealed a significant increase in the number and swelling of Kupffer cells and sinusoidal endothelium in the liver of the treated mice.

Adjuvants, Immunologic↗
PubMedDate not supplied

Induction of tumor degeneration by sodium benzylideneascorbate.

Intravenous administration of sodium benzylideneascorbate (SBA) rapidly necrotized inoperable human lung cancer, and induced degeneration of 3'-methyl-4-dimethylaminoazobenzene-induced rat hepatocellular carcinoma (vacuolar, eosinophilic degeneration, nuclear debris) without affecting the serum glutamic oxaloacetic transaminase, gamma-glutamyl transpeptidase and total protein levels. Cultured normal human lung and skin fibroblasts, and human glioma and glioblastoma cell lines were relatively resistant to SBA, when compared to human myelogenous leukemic cell lines. SBA had no apparent host immunopotentiation activity such as stimulation of cytokine action or production; activation of monocyte or polymorphonuclear cells; or modulation of poly (ADP-ribose) glycohydrolase activity. The data suggest that the antitumor activity of SBA might be produced by direct action of authentic SBA or its metabolized form(s), rather than by immunopotentiation of the hosts.

Animals↗
PubMedDate not supplied

Rat hepatocellular carcinogenesis and proliferating cell nuclear antigen expression induced by 3'-methyl-4-dimethylaminoazobenzene.

The experimental conditions for the induction of rat hepatocellular carcinoma by oral administration of 3'-methyl-4-dimethylaminoazobenzene (DAB) were established. Hematoxylin-eosin (HE) staining of the liver sections revealed that precancerous lesions, characterized by small proliferation nest, hyperplastic nodule, oval cell and adenofibrosis, were observed 2 months after DAB administration. The highest incidence of hepatocellular carcinoma, trabecular carcinoma and mixed form of hepatocellular and cholangiocarcinoma was observed after 3-5 months and remained for an additional 2 months, even if the rats were continuously fed with DAB-free fodder. Immunohistochemical study with monoclonal antibody against proliferation cell nuclear antigen (PCNA) revealed that the relative number of PCNA-positive cells increased with the progress of the carcinoma. The present study confirms the previously reported usefulness of the PCNA immunostaining method for prognosis and assessment of the malignancy of carcinoma.

Animals↗
PubMedDate not supplied

Effect of sodium benzylideneascorbate on chemically-induced tumors in rats.

Intravenous administration of sodium benzylideneascorbate (SBA) dose-dependently induced degeneration (vacuolar and eosinophilic degeneration and cell shrinkage and nuclear condensation, which are characteristic of apoptotic cell death) of 3'-methyl-4-dimethylaminoazobenzene-induced rat hepatocellular carcinoma. SBA did not significantly induce lymphocyte infiltration and fibrosis in the liver, nor damage the gross morphology of kidney and spleen cells. SBA failed to stimulate the production of tumor necrosis factor and interleukin-1 beta in both in vitro and in vivo systems. These results may suggest a direct antitumor action of SBA via induction of apoptosis in the tumor. However, SBA did not significantly affect the doubling time, or the extent of invasion and differentiation of dimethylhydrazine-induced colon carcinoma in rats. These data suggest that the conditions of SBA administration should be re-established for each tumor sample to produce maximum antitumor activity.

Animals↗
PubMedDate not supplied

Role of hydrogen peroxide in antitumor activity induction by sodium 5,6-benzylidene-L-ascorbate.

Role of hydrogen peroxide (H2O2) in the induction of antitumor activity against chemically-induced rat hepatocellular carcinoma by sodium 5,6-benzylidene-L-ascorbate (SBA) was investigated. ESR spectroscopy demonstrated that rat liver homogenate of cancerous tissue significantly enhanced the radical intensity of SBA more potently than that of precancerous or normal tissue. The peroxyoxalate chemiluminescence method demonstrated that SBA significantly enhanced the production of H2O2-derived chemiluminescence intensity in the liver homogenates, and the effect of SBA was greater in cancerous tissue than in precancerous or normal tissue. Addition of ascorbic acid, a degradation product of SBA, showed similar but slightly weaker stimulation effects. These data suggest that antitumor activity of SBA in vivo might, at least in part, be due to H2O2 production.

Animals↗