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Biomedical subjects

T Tada

Publications and source records attributed to T Tada.

At least 325 records · Page 18Linked to original sources
PubMed1987

Alterations in the proliferative response of T cells from aged and chimeric mice.

Factors involved in the nonspecific and specific proliferative responses of T cells were examined in the A/J strain of mice that were physiologically aged in the specific pathogen-free condition. In aged A/J mice, the production of IL-1 and IL-2 from optimally stimulated peritoneal macrophages and splenic T cells was significantly decreased, while the production of IL-3 by T cells was increased. T cells from old mice showed a higher threshold for concanavalin A stimulation for the induction of IL-2 receptors. The same T cells responded only slightly in the mixed lymphocyte reaction (MLR) stimulated by allogeneic class II antigens, while they showed a high background stimulation without stimulators. The addition of syngeneic accessory cells did not increase the proliferative response of T cells from aged animals. T cells from bone marrow chimeras constituted by transferring stem cells from young A/J into irradiated old B10.A mice (young A/J----old B10.A chimeras) showed a pattern very similar to that of old A/J T cells, whereas those from the old A/J----young B10.A chimeras exhibited a response pattern comparable to that of normal young A/J cells. These results indicated that the proliferative responses in aged animals are abnormal, partially due to the alterations in the interleukin cascade. Some changes are probably due to the effect of environment where T cells undergo early differentiation, because bone marrow stem cells from aged mice can generate T cells with normal functions when differentiated in the young environment.

Aging↗
PubMed1987

Immunoreactive epidermal growth factor in mouse digestive organs. Use of a sensitive enzyme immunoassay.

A sandwich enzyme immunoassay (ELISA) system for mouse epidermal growth factor (EGF), which has a high sensitivity (500 fg/tube), has been established. It makes it possible to measure minute amounts of immunoreactive EGF in various mouse tissue without pretreatment. The immunoreactive EGF concentrations in digestive tissues of adult mice were much lower than previously reported. A significant sex difference was detected not only in the submandibular gland, but also in the oesophagus and forestomach. Although sialoadenectomy decreased the immunoreactive EGF contents in the alimentary tract to 4.2-23.8% of the pre-operative levels, the duodenal immunoreactive EGF was unaffected. Positive immunostaining was observed in the submandibular and sublingual gland, but not in the other digestive tissues, including the duodenum. These data implied that most of the EGF in the digestive tissues was derived mainly from the saliva and that a small amount of endogenous EGF existed in the duodenum. The physiological role of exogenous salivary EGF in the alimentary tract and the origin of endogenous duodenal EGF are discussed.

Animals↗
PubMed1987

Incidence of atrophic gastritis with age in Japan and Canada.

With methylene blue dye spraying endoscopy 392 Japanese outpatients with gastric diseases, and 253 Japanese and 84 Canadian outpatients free of gross findings in the stomach were investigated on chronic atrophic gastritis in special reference to intestinal metaplasia. Second, with the same technique 176 asymptomatic healthy residents in Kyoto, Japan, were also investigated, in which 50 residents were followed for two years and 32 subjects for four years. In each population subjects, with increasing age the fundic-pyloric (F-P) border shifted cephalad indicating atrophy of the fundic mucosa. Japanese subjects, however, showed greater variation in location of the F-P border, and also greater in symptomatic outpatients than in asymptomatic healthy subjects. The reduction in fundic gland area with aging was followed by intestinal metaplasia. In addition, our follow-up study indicates that atrophic gastritis was most likely to advance gradually with increasing age, even in asymptomatic residents.

Adolescent↗
PubMed1987

Aneurysms of the basilar artery trunk.

Ten cases of basilar artery trunk aneurysms are reported; nine were operated on by a middle subtemporal approach and one by a pterional transsylvian technique. The middle subtemporal approach facilitated clipping of aneurysms located as deep as 25 mm below the posterior clinoid process as seen on the lateral views of the angiogram, such that the junction of the vertebral arteries was visible in most cases. The authors emphasize the usefulness of direct retraction of the trigeminal nerve, the pons, and the aneurysm itself; occasionally, drilling off the pyrimidal edge is also valuable. Surgical results were satisfactory in seven cases and poor in one; two patients died.

Adult↗
PubMed1987

[Combination chemotherapy concurrent with small-dose radiation therapy of small cell carcinoma of the lung].

Forty consecutive patients with small cell carcinoma of the lung were treated with chemotherapy, radiotherapy or both. Of 34 patients treated with chemotherapy, 24 were treated with combination chemotherapy, containing cyclophosphamide vincristine methotrexate and procarbazine, concurrent with small dose radiation therapy (500cGy/5 fraction) as a chemosensitizer (COMPrt). The response rate to this regimen was 81% (29% complete) and the 2 year survival rate was 28.6%. These results have been superior to other regimens and the toxicity was not see to be any higher. After completion of COMPrt regimen, 10 patients were treated with intrathoracic radiation therapy (average dose 3000cGy) and 3 received surgical treatment. Radiation therapy improved the 2-year survival rate (42.2%) when compared with those patients who received no radiation therapy (18.2%). Three patients received surgical treatment were considered to be disease-free for 23, 17, and 9 months respectively, after induction of chemotherapy.

Adult↗
PubMed1987

Endothelial regeneration. IX. Arterial injury followed by rapid endothelial repair induces smooth-muscle-cell proliferation but not intimal thickening.

Rat thoracic aortas were denuded of endothelial cells with a fine nylon filament, which removed a row of endothelium approximately 100 mu in width and caused platelets to adhere to the exposed subendothelium. A further group of rats was subjected to a sham operation where only the abdominal aorta was injured, and another group of rats was used as controls. Each animal was continuously labeled with 3H-thymidine (6.7 Ci/mM, 10 microCi/hr) for 7 days, at which time they were killed and the aortas perfusion-fixed with aldehydes. Sections of each aorta were processed for autoradiography. The thoracic aortas from animals subjected to the nylon filament injury showed no intimal thickening, but there was a significant increase in the thymidine index of the medial smooth muscle cells (SMCs) as compared with aortas from sham operation or control animals (1.02% +/- 0.44% versus 0.19% +/- 0.13% versus 0.15% +/- 0.12%). This experiment showed that continuous administration of 3H-thymidine permitted the detection of a small but significant increase in replication rates that could not be detected by the standard bolus administration of 3H-thymidine, and that selected loss of endothelium with minimal trauma to the vessel wall caused SMC proliferation without intimal thickening. These findings suggest that platelets may indeed provide SMC proliferation, but that migration of these cells into the intima may be controlled by different factor(s).

Animals↗
PubMed1987

[A case of metastasis from a colon carcinoma to an intracranial oligodendroglioma].

The following case of a metastasis from a colon carcinoma to an intracranial oligodendroglioma is reported. Radiologically, it was difficult to diagnose that the colon carcinoma had metastasized to an oligodendroglioma. A craniotomy was then performed. Histologically, it was diagnosed that the tumor was a moderately differentiated adenocarcinoma and oligodendroglioma. Also, in conclusion, a comparison of Japanese and foreign cases of metastasis from tumor to tumor is reviewed.

Adenocarcinoma↗
PubMed1986

The assignment of chain specificities for anti-Ia monoclonal antibodies using L cell transfectants.

The chain specificities of 18 Ak and 26 Ab-reactive anti-Ia monoclonal antibodies have been determined. L cells were transfected with haplotype-matched (A alpha k:A beta k, A alpha b:A beta k) or haplotype-mismatched (A alpha k:A beta b, A alpha b:A beta k) cDNA pairs, lines expressing high levels of surface A complex were selected, and antibody reactivity with a panel of reagents was assessed by cytofluorimetric analysis. Most of the antibodies recognized a determinant specified by one chain, either alpha or (more commonly) beta. A few examples of more complex determinants were also observed. A knowledge of the chain specificities of anti-Ia monoclonal antibodies should prove useful for a variety of studies aimed at dissecting Ia structure-function relationships.

Animals↗
PubMed1986

Serologic heterogeneity in I-J determinants associated with functionally distinct T cell regulatory factors.

Information transfer among regulatory T cell subsets is mediated by biologically active T cell factors. Many of these factors are comprised of two molecules: one that binds antigen, and another that is I-J+ and determines the self recognition capability of the factor (I-J molecule). In the in vitro response to sheep red blood cells, we used three functionally distinct I-J+ factors to study the relationship between polymorphic I-J determinants and the biological activity of these factors. Our study shows that several monoclonal I-J antibodies react with I-J molecules associated with T suppressor-inducer factor (TsiF) and T suppressor-effector factor (TseF), but not with T contrasuppressor inducer factor (TcsiF). In contrast, a different set of monoclonal I-J reagents reacts with TcsiF but not TsiF or TseF. Finally, some monoclonal I-J antibodies distinguish between I-J molecules associated with TsiF and TseF. Thus anti-I-J reagents differentially react with I-J determinants on regulatory factors, and this differential pattern of reactivity correlates with the functional activity of the factors. The possible relationship between I-J heterogeneity and the biological function of I-J molecules in regulation is discussed.

Animals↗
PubMed1986

Ir gene expression on T cells: effect of a monoclonal antibody directed against I region-controlled determinants on T cells.

A monoclonal antibody directed at an I region-controlled epitope uniquely expressed on T cells (Iat) was studied for its in vivo effect on the antibody response under the control of an Ir gene. The antibody was produced by a hybridoma made from A.TH spleen cells immune to A.TL (anti-Ik), that was selected for its reactivity with T but not B cells and macrophages, and thus was designated as anti-IatK. The injection of this anti-Iatk into H-2k, H-2b and H-2k X bF1 mice resulted in the suppression of antibody response to poly-L-(His,Glu)-poly-D,L-Ala--poly-L-Lys [(H,G)-A--L] in H-2k and F1 mice but not that to poly-L-(Tyr,Glu)-poly-D,L-Ala--poly-L-Lys [(T,G)-A--L] both in H-2b and F1 mice. The adoptive cell transfer of the combinations of anti-Iatk- or normal mouse serum-treated T and B cells into irradiated hosts demonstrated that anti-Iatk primarily affected (H,G)-A--L-specific helper T cells but not B cells and macrophages, resulting in the specific elimination of the antibody response. Suppressor T cells were not induced by the treatment with anti-Iatk. The antibody specifically eliminated the (H,G)-A--L-specific but not (T,G)-A--L-specific helper T cells in F1 spleen cells that had been primed with both (H,G)-A--L and (T,G)-A--L. The results indicated that anti-Iatk affected the H-2k-associated Ir gene function born by T cells but not by antigen-presenting cells, which was expressed on F1 helper T cells with apparent exclusion of the other allele, and implied that the Iat antigen on helper T cells is one of the sites of expression of Ir genes.

Animals↗
PubMed1986

Does the deletion within T cell receptor beta-chain gene of NZW mice contribute to autoimmunity in (NZB X NZW)F1 mice?

To determine the transacting genetic factors of NZW contributing to the development of autoimmune disease in (NZB X NZW)F1 (B/W F1) mice, we examined the relationship between the T cell receptor beta chain gene deletion and the severity of autoimmune manifestations in 76 B/W F1 X NZB backcross mice. Very high association between the T cell receptor beta chain gene deletion and the development of autoimmune manifestations including the production of IgG anti-DNA antibodies and circulating retroviral gp70 immune complexes was observed, indicating that a defect in the NZW T cell receptor beta chain gene or a locus closely linked to it contributes to the autoantibody formation in B/W F1.

Animals↗
PubMed1986

Immunohistochemical cell kinetic study of human lung cancer by using monoclonal antibody to bromodeoxyuridine.

In vitro cell kinetic studies of 27 surgically removed human lung cancers were performed by the immunohistochemical procedure using monoclonal antibody to bromodeoxyuridine (BrdU). BrdU was incorporated under hyperbaric oxygenation, and labeled cells were found to be evenly distributed in the tissue blocks. A comparison of the in vitro and in vivo labeling index (L.I.) in human tumors transplanted to nude mice showed good correlation. Surgically resected adenocarcinoma of the human lung had a significantly lower L.I. than squamous cell carcinoma, the mean values being 6.0% and 17.2%, respectively. In adenocarcinoma, L.I. values disclosed a trend toward a higher L.I. in poorly differentiated carcinoma.

Animals↗
PubMed1986

Lymphocyte subsets identified by monoclonal antibodies in healthy children.

The distributions of lymphocyte subsets and monocytes in the peripheral blood mononuclear leukocytes of 72 normal children from 2 months to 13 5/12 yr were examined using quantitative immunofluorescence analysis with monoclonal antibodies. Distinct decreases with age were found in the total leukocyte counts, the percentages and the absolute numbers of peripheral blood mononuclear leukocytes. The percentages of Leu-2a+ cells, Leu-7+ cells, and Leu-M3+ cells significantly increased with age, whereas the percentages of Leu-3a+ cells, Leu-4+ cells, and 2H7+ cells significantly decreased with age. As a result, ratios of Leu-3a+/Leu-2a+ decreased with age. No prominent differences with age were found in the proportions of Leu-10+ cells and HLA-DR+ cells.

Adolescent↗