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H Oya

Publications and source records attributed to H Oya.

At least 55 records · Page 3Linked to original sources
PubMed2000

[Pulmonary thromboendarterectomy for chronic pulmonary thromboembolism in three patients with systemic lupus erythematosus and antiphospholipid syndrome].

Pulmonary hypertension (PH) is a serious and often fatal complication of systemic lupus erythematosus (SLE). Several potential mechanisms have been postulated for narrowing of vessels as a result of pulmonary vasculitis and pulmonary thromboembolism caused by antiphospholipid antibodies. Pulmonary thromboendarterectomy for chronic pulmonary thromboembolism is performed to alleviate pulmonary hypertension. We report three rare cases of SLE with antiphospholipid syndrome in patients who presented with PH secondary to chronic pulmonary thromboembolism. Pulmonary thromboendarterectomy was performed, and all patients remained well without deterioration of PH after surgery. Pulmonary thromboendarterectomy should be considered as an effective method of treatment for this disease.

Adult↗
PubMed1999

Mechanisms underlying immunologic states during pregnancy: possible association of the sympathetic nervous system.

NK and extrathymic T cells are abundant in the decidua of the pregnant uterus. To determine how this unique pattern is induced, overall populations of leukocytes were examined in the blood and other tissues in pregnant women. Time-kinetic studies showed that a basal change of leukocytes during pregnancy was granulocytosis and lymphocytopenia in the blood. This change might be due to sympathetic nerve activation during pregnancy, because the administration of catecholamine is known to activate myelopoiesis in the bone marrow. In addition to the numerical change, the functional activation of NK and extrathymic T cells also seemed to be present. This might be due to NK cells and extrathymic T cells (as well as granulocytes), which carry a high density of surface adrenergic receptors. Such functional activation of NK and extrathymic T cells was more prominent in the blood and urine in patients with preeclampsia and hyperemesis gravidarum than in normal pregnant women. The present results suggest that the activation of granulocytes, NK cells, and extrathymic T cells is essential for the maintenance of pregnancy but that overactivation thereof may be responsible for the onset of pregnancy disorders.

Adult↗
PubMed1999

Administration of glucocorticoids markedly increases the numbers of granulocytes and extrathymic T cells in the bone marrow.

Glucocorticoids, steroid hormones, are widely used as an anti-inflammatory drug. However, clinicians have sometimes encountered adverse drug reactions such as ulcers and tissue damage. In this study, we investigated how such adverse reactions of glucocorticoids are evoked, using an experimental mice model. When hydrocortisone (0.5 or 1.0 mg/day/mouse) was administered daily for 2 weeks, severe leukocytopenia was induced in all immune system organs. However, granulocytes (Gr-1(+)Mac-1(+)) were increased in number in the bone marrow and peripheral blood. This seemed to be due to an elevated level of myelopoiesis in the bone marrow. As well as increasing in number, granulocytes were functionally activated as estimated by the Ca2+ influx and superoxide production. The proportion of primordial T cells (CD3(int)IL-2Rbeta+) in the thymus and the number of primordial T cells in the bone marrow also increased. Mice administered hydrocortisone became susceptible to stress. Thus, these mice showed gastric ulcers when they were exposed to restraint stress for 12 h. These results suggest that activated granulocytes and primordial T cells might provide a mechanism involved in steroid ulcers and tissue damage, possibly through the superoxide production of granulocytes and the autoreactivity of primordial T cells.

Animals↗
PubMed1999

Expansion of extrathymic T cells as well as granulocytes in the liver and other organs of granulocyte-colony stimulating factor transgenic mice: why they lost the ability of hybrid resistance.

When we attempted to characterize the immunological state in G-CSF transgenic mice, a large number of not only granulocytes but also lymphoid cells expanded in various immune organs. Such lymphoid cells were present at unusual sites of these organs, e.g., the parenchymal space in the liver. We then determined the phenotype of these lymphoid cells by immunofluorescence tests. It was demonstrated that CD3intIL-2Rbeta+ cells (i.e., extrathymic T cells), including the NK1.1+ subset of CD3int cells (i.e., NKT cells), increased in the liver and all other tested organs. These T cells as well as NK cells mediated NK and NK-like cytotoxicity, especially at youth. However, they were not able to mediate such cytotoxicity in the presence of granulocytes. This result might be associated with deficiency in the hybrid resistance previously ascribed to these mice. In other words, G-CSF transgenic mice had a large number of extrathymic T cells (including NKT cells) and NK cells that mediate hybrid resistance, but their function was suppressed by activated granulocytes. Indeed, these granulocytes showed an elevated level of Ca2+ influx upon stimulation. The present results suggest that, in parallel with overactivation of granulocytes, extrathymic T cells and NK cells are concomitantly activated in number but that their function is suppressed in G-CSF transgenic mice.

Age Factors↗
PubMed1999

Consistent infiltration of thymus-derived T cells into the parenchymal space of the liver in normal mice.

We previously reported that extrathymic T cells (intermediate T-cell receptor cells [TCR(int) cells]) are in situ generated in the parenchymal space of the liver in mice. They subsequently migrate to the sinusoidal lumen. In this study, we characterized how such extrathymic T cells, natural killer (NK) cells, and thymus-derived T cells (high T-cell receptor cells [TCR(high) cells]) localized in the parenchymal space or the sinusoidal lumen of mice. To this end, liver irrigation with physiological saline from the portal vein was performed and the distribution of lymphocyte subsets was compared between the liver (i.e., lymphocytes in the parenchymal space) and the irrigation solution (i.e., lymphocytes in the sinusoidal lumen). Extrathymic T cells and NK cells were found to be abundant in both the liver and sinusoidal lumen. As expected, thymus-derived T cells were abundant in the sinusoidal lumen. However, a significant proportion of thymus-derived T cells were always present in the parenchymal space, even after intensive irrigation with or without collagenase. These results suggest that thymus-derived T cells may consistently infiltrate the parenchymal space from the sinusoidal lumen in normal mice. This possibility was confirmed by (1) the injection of B6 splenic cells (TCR(high) cells) or the thymus graft into B6-nu/nu mice (presence of only TCR(int) cells) and by (2) using parabiotic mice of B6.Ly5.1 and B6.Ly5.2 strains (sharing circulation) in conjunction with immunofluorescence tests and immunohistochemical staining. In other words, inverted routes of migration and homing between extrathymic T cells and thymus-derived T cells exist in the liver.

Animals↗
PubMed1999

The majority of lymphocytes in the bone marrow, thymus and extrathymic T cells in the liver are generated in situ from their own preexisting precursors.

Parabiotic pairs of B6.Ly5.1 and B6.Ly5.2 mice were used to investigate how lymphocytes in various organs and various lymphocyte subsets mixed with partner cells. The origin of partner cells was determined by using anti-Ly5.1 mAb in conjunction with immunofluorescence tests. Parabiosis was also produced after the irradiation of B6.Ly5.2 mice at various doses to prepare an immunosuppressive partner. Irrespective of irradiation, lymphocytes and other hematopoietic cells in the bone marrow and lymphocytes in the thymus showed a low mixture of partner cells in comparison with those of all other organs tested. On the other hand, lymphocytes in the blood, spleen, and lymph nodes became a half-and-half mixture of their own cells and partner cells by 14 days after parabiosis. Among lymphocyte subsets, intermediate CD3 cells (i.e., CD3int cells) and NKT cells (i.e., NK1.1+ subset of CD3int cells) in the liver also showed a low mixture of partner cells. The present results raise the possibility that lymphocytes in the bone marrow and thymus, and extrathymic T cells in the liver might be in situ generated from their own preexisting precursor cells. Another observation was that, after irradiation, partner cells showed accelerated mixture even if they showed a low mixture under non-irradiated conditions. However, only lymphocyte subsets with the same phenotype as those of preexisting cells entered the corresponding sites.

Animals↗
PubMed1998

Genotype-phenotype correlation of patients with multiple endocrine neoplasia type 2 in Japan.

BACKGROUND: Multiple endocrine neoplasia type 2 (MEN 2) is a hereditary syndrome characterized by medullary thyroid carcinoma (MTC), pheochromocytoma and hyperparathyroidism. MEN 2 is caused predominantly by germ-line mutations of the RET proto-oncogene. This study aimed to clarify the genotype-phenotype correlation in MEN 2 patients in Japan in order to modify the clinical management according to the genotype. METHODS: Constitutive DNA of 64 MEN 2 patients (48 kindreds) were searched for mutations at exons 10, 11, 13, 14 and 16 of the RET proto-oncogene using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), direct sequencing and restriction enzyme digestion. The clinical characteristics of the patients were obtained from a previous nationwide questionnaire survey. RESULTS: Overall, 62 (96.9%) out of 64 patients had a germ-line point mutation at the hot spots. MTC and pheochromocytoma occurred equally in every genotype except C630S. Specific genotype had a correlation between tumor size and age at the operation for MTC or extent of MTC, i.e. C618S developed late onset type of MTC as compared with that of C634R, C634Y and M918T. Small MTC in C634R may be less aggressive than those in C634Y and M918T. CONCLUSIONS: DNA testing has good clinical implications for the management of patients with MEN 2 and the timing and operative procedures of thyroidectomy can be modified according to the genotype.

Adrenal Gland Neoplasms↗
PubMed1998

Patients' views on residual blood use for research purposes.

In order to document patients' views on residual blood use for research purposes, a questionnaire survey was conducted at Aichi Cancer Center Hospital in October 1997. Subjects were patients who had undergone blood tests at a central blood sampling room in the morning during the week of the study enrollment. The questionnaire was handed out and collected at a waiting area in front of the blood sampling room. Of the 583 patients to whom we tried to hand out the questionnaire, 558 participated (258 males, 294 females, and 6 of sex unknown) and 25 refused. Those who regarded research to improve health care as important were 76.7% of those sampled. Only 28 patients (5.0%) answered that they would not permit the use of their residual blood for research purposes. Although logistic analysis did not detect significant factors influencing the giving of permission, the percentage who would not permit the use of their residual blood for research purposes was significantly higher in cancer outpatients (6.7%) than in inpatients (1.0%). It seems desirable for hospitals to establish an open policy concerning residual blood use for research purposes.

Blood↗
PubMed1998

[A case of pleuritis caused by strongyloides in a carrier of T-cell lymphoma virus type I (HTLV-I)].

A 73-year-old woman was admitted to our hospital complaining of dyspnea, fever and general edema. Chest roentgenogram showed bilateral pleural effusion and cardiomegaly. Cardiovascular examination demonstrated atrial tachycardia and left ventricle dysfunction, suggesting congestive heart failure. She was sero-positive for human T-cell lymphoma virus I (HTLV-I). The dyspnea and general edema improved after therapy for heart failure. Because the pleural effusion persisted after therapy, thoracentesis was performed. The pleural effusion was an exudate, and Strongyloides sterocoralis was detected by microscopy. Two courses of thiabendazole (1,500 mg/day, 3 days) were given orally. After this therapy, the pleural effusion improved markedly. This case suggests that Strongyloides stercoralis may be a causative agent of pleuritis in HTLV-I endemic areas.

Aged↗
PubMed1996

Changes in gene expression of growth factors and their receptors during castration-induced involution and androgen-induced regrowth of rat prostates.

To find candidates for the mediator of the growth-promoting action of androgen in rat prostates, the changes in the steady-state levels of mRNAs coding for several growth factors and their receptors were examined by Northern blot analysis during castration-induced involution, and subsequent regrowth induced by androgen in the ventral and dorsolateral lobes. The changes in the growth factor systems and a typical secretory protein in the ventral lobe were similar to, but more prominent than, those in the dorsolateral lobe, showing the higher androgen dependency of the ventral lobe. Among the growth factors and their receptors investigated, only epidermal growth factor (EGF) showed apparent positive androgen dependency: EGF mRNA content in the ventral lobe decreased to about 30% of the normal level within 24 hr after castration, and increased, attaining about 200-300% of the normal level 3-5 days after androgen administration to castrated rats. mRNAs coding for all other factors examined, i.e., transforming growth factor-alpha (TGF-alpha), EGF receptor, basic fibroblast growth factor (bFGF), keratinocyte growth factor (KGF), FGF receptor 1, TGF-beta1, TGF-beta type II receptor, hepatocyte growth factor (HGF), and c-MET/HGF receptor, increased after castration in greater or lesser degree, and after a brief pause or a decrease some of them increased again attaining a second peak 3-5 days after androgen replacement. The second increase was evident in TGF-alpha, EGF receptor, KGF, and c-MET mRNAs. These results indicate the possibility that multiple growth factor-receptor systems participate in the androgen-dependent regrowth of castrated rat prostates.

Androgens↗
PubMed1994

Identification of probasin-related antigen as cystathionine gamma-lyase by molecular cloning.

We reported previously that a monoclonal antibody against probasin (rat prostatic secretory protein) recognizes a 40-kDa protein localized in rat liver and kidney. The protein (probasin-related antigen, PRB-RA) may participate in a specific differentiated function of these tissues. To clarify the molecular nature of PRB-RA, a series of cDNA clones coding for the protein were isolated from a rat liver expression library using an affinity-purified polyclonal antibody. The amino acid sequence deduced from the determined cDNA sequence included sequences identical with those of proteolytic fragments of PRB-RA, which covered about 70% of the deduced sequence. Northern blot hybridization of poly(A)+ RNA isolated from rat tissues showed the presence of predominant and minor mRNA species of about 2.0 and 4.3 kilobases, respectively, in the liver and kidney. A sequence homology search revealed that PRB-RA is almost completely identical to rat cystathionine gamma-lyase (cystathionase) and that it does not show overall homology with probasin. Three candidates for an epitope common to probasin and PRB-RA were found on close examination of the amino acid sequences of the two proteins. A synthetic peptide, TYFRRI, corresponding to one of the candidates, neutralized the reactivity of the anti-probasin monoclonal antibody to both probasin and PRB-RA on Western blot analysis. These results show that PRB-RA/cystathionase is neither structurally nor functionally related to probasin except for a common epitope and that cystathionase, a cystein-producing enzyme, is localized in urinary tubular epithelial cells in a highly restricted region of the kidney in addition to in liver parenchymal cells.

Amino Acid Sequence↗
PubMed1994

Development of Babesia ovata in the salivary glands of the nymphal tick, Haemaphysalis longicornis.

The development of Babesia ovata in the salivary glands of nymphal Haemaphysalis longicornis ticks was morphologically studied for 4 days of feeding of tick on rabbits. Babesia ovata showed two forms (sporont and sporozoite) in the budding process. Sporozoites were formed in the acinar cells of salivary glands and released from the hollow cytoplasmic area of these cells by day 4 of feeding.

Animals↗
PubMed1993

Developmental changes in the respiratory chain of Ascaris mitochondria.

The Ascaris larval respiratory chain, particularly complex II (succinate-ubiquinone oxidoreductase), was characterized in isolated mitochondria. Low-temperature difference spectra showed the presence of substrate-reducible cytochromes aa3 of complex IV, c+c1 and b of complex III (ubiquinol-cytochrome c oxidoreductase) in mitochondria from second-stage larvae (L2 mitochondria). Quinone analysis by high-performance liquid chromatography showed that, unlike adult mitochondria, which contain only rhodoquinone-9, L2 mitochondria contain ubiquinone-9 as a major component. Complex II in L2 mitochondria was kinetically different from that in adult mitochondria. The individual oxidoreductase activities comprising succinate oxidase, and fumarate reductase were determined in mitochondria from L2 larvae, from larvae cultured to later stages, and from adult nematodes. The L2 mitochondria exhibited the highest specific activity of cytochrome c oxidase, indicating that L2 larvae have the most aerobic respiratory chain among the stages studied. The Cybs subunit of complex II in L2 and cultured-larvae mitochondria exhibited different reactivities against anti-adult Cybs antibodies. Taken together, these results indicate that the complex II of larvae is different from its adult counterpart. In parallel with this change in mitochondrial biogenesis, biosynthetic conversion of quinones occurs during development in Ascaris nematodes.

Animals↗
PubMed1992

An anti-probasin monoclonal antibody recognizes a novel 40-kDa protein localized in rat liver and a specific region of kidney urinary tubule.

Immunoblotting with a monoclonal antibody against probasin (rat prostatic secretory protein) showed that a 40-kDa protein antigenically related to probasin was localized in rat liver and kidney. The contents of probasin in these organs were negligible. Immunostaining revealed that the 40-kDa protein (probasin-related antigen: PRB-RA) was expressed in the liver parenchymal cells and the kidney urinary tubular epithelial cells in outer stripe. The content of PRB-RA in the kidney was low during 0 to 2 weeks of age, then rapidly increased about 10-fold from 2 to 8 weeks of age. The content in the liver increased about 2-fold during the period, reaching a value of 10-12 ng/micrograms protein, which was ten times higher than that in the kidney. PRB-RA was purified from rat liver by ion-exchange chromatography, gel filtration and fast protein liquid chromatography on a hydroxyapatite column. The purified protein formed insoluble aggregates in the absence of a detergent, and it had a blocked amino terminal. The amino acid sequence of a peptide generated by tryptic digestion of alkylated PRB-RA was determined. Computer analysis showed that there was no protein having a significant homology with the peptide. These results indicate that a novel 40-kDa protein with a structural similarity to probasin is localized in rat liver and kidney, and might bear a function specific to these organs.

Aging↗
PubMed1991

A comparative study of the effects of phebrol on the respiratory chains of rat liver, Biomphalaria glabrata and Oncomelania nosophora.

1. Phebrol (sodium 2,5-dichloro-4-bromophenol), a synthetic molluscicide against Oncomelania nosophora, showed a dual effect on rat liver submitochondria, acting as an uncoupler at low concentrations (approximately 10 microM) and an inhibitor of succinate-cytochrome c reductase at high concentrations. 2. Phebrol also inhibited the enzymes responsible for succinate-fumarate conversion, i.e. the succinate-cytochrome c reductase, fumarate reductase and NADH-cytochrome c reductase of the mitochondrial fraction from Biomphalaria glabrata. 3. Kinetic inhibition studies showed succinate-cytochrome c reductase of B. glabrata and O. nosophora to be more sensitive than that of rat liver toward phebrol. 4. Phebrol accumulated in whole tissues of B. glabrata and O. nosophora and had significant effects on the production of succinate, fumarate and malate by these snails. 5. On the basis of these results, the possible sites of inhibition by phebrol of snail respiratory chains are proposed.

Animals↗