Search PubMed⌕ Search

Biomedical subjects

K Tsukamoto

Publications and source records attributed to K Tsukamoto.

At least 271 records · Page 15Linked to original sources
PubMed1987

[Chromosomal investigation in infertile cases of azoospermia].

Chromosomal examination in 85 patients with azoospermia revealed 62 patients (73%) with the karyotype 46, XY and 23 patients (27%) with other abnormal karyotypes. In this population, there were 17 patients with 47, XXY. Other anomalies were: 46, XYp+, 46, XXp+, 46, XYp-, 45, X, t (Ynf; 21), 45, XY, t (13q 15q), and 46, XY, r (18). Serum LH and FSH levels were high and testosterone level was low in the patients with 47, XXY compared with the other 6 patients (p less than 0.01). Also the mean value of testicular volume was low in the patients with 47, XXY (p less than 0.05).

Adult↗
PubMed1987

Suppression of pulmonary tumour metastasis in mice by recombinant human interleukin-2: role of asialo GM1-positive cells.

Recombinant human interleukin-2 (rIL-2) suppressed metastatic tumour colony formation in the lungs of C57BL/6 mice bearing Lewis lung carcinoma (3LL). In tumour-bearing mice given rIL-2, non-specific killer cells that were cytotoxic not only against natural killer-sensitive YAC-1 cells but also against 3LL cells in an in vitro 51Cr-release assay were concomitantly induced as tumour metastasis was suppressed. These non-specific killer cells were mostly removed by treatment with anti-Thy 1.2 or anti-asialo GM1 antibody plus complement (C) in vitro but not with anti-Lyt 1.2 or anti-Lyt 2.2 plus C, indicating that they were positive for Thy 1 and asialo GM1 but not for Lyt 1 and Lyt 2. In order to explore the mechanism by which rIL-2 suppressed tumour metastasis, we examined the clearance of intravenously injected 51Cr-labelled 3LL cells in the lungs of mice given rIL-2. The rate of tumour cell clearance was increased. This enhanced clearance was almost completely removed by injecting anti-asialo GM1 antibody. In addition, the injection of anti-asialo GM1 antibody also depleted most of the non-specific killer cells induced by administering rIL-2. These results indicate that asialo GM1-positive cells are not only cytotoxic in vitro but also play a critical role in the clearance of 3LL cells in the lungs in vivo. Our results indicate that asialo GM1-positive cells play an important role as anti-metastatic effector cells in suppressing the metastasis of 3LL cells in mice given rIL-2.

Animals↗
PubMed1987

Monoclonal antibodies against rat brain protein kinase C and their application to immunocytochemistry in nervous tissues.

Three monoclonal antibodies were prepared against rat brain soluble protein kinase C. Two of the antibodies, CKI-97 (IgG2b subclass) and CKII-90 (IgG1 subclass), showed weak binding to native protein kinase C. The third antibody, CKI-33 (IgG2b subclass), showed no binding. However, the mixture of CKI-97, CKII-90, and CKI-33 exhibited much stronger binding activity to this protein kinase than any of the antibodies alone. Although none of these antibodies showed protein kinase C-neutralizing activity, Western blot analysis indicated that these antibodies reacted specifically with protein kinase C, presumably its subspecies, that is present predominantly in nervous tissues. Immunocytochemical studies shows that these antibodies can be used for identification of this enzyme in nervous tissues. In rat Purkinje cells, the immunoreactive material was present throughout the cytoplasm, including dendrites and axons, but was poorly represented in the cell nucleus. In cerebellum, the localization of protein kinase C appears to be very similar to that of cGMP-dependent protein kinase.

Animals↗
PubMed1987

[A case of Werner's syndrome associated with bladder cancer].

A 41-year-old woman was diagnosed as having Werner's syndrome associated with bladder cancer. The patient noticed sudden, total gross hematuria in September, 1985. Cystoscopy revealed a papillary tumor with a stalk that was accompanied by a daughter tumor and concealed the left ureteral orifice. The tumors were 25 X 20 X 10 mm and 15 X 10 X 5 mm. Double contrast cystograms, computed tomography and transurethral echo showed no invasion of muscle layer. Intravesical instillation of mitomycin (10 mg), cylocide (300 mg) and adriacin (30 mg) was carried out 3 times per week for 4 weeks. Tumor size was reduced, and then TUR was performed. High power section of the removed bladder tumor showed pathologically PNT, TCC, grade II, INF alpha, pTla, lyo and v(-). The patient had such clinical manifestations as short stature with low body weight, thin limbs and stocky trunk, senile face, early graying hair, highpitched voice, bilateral cataracts, osteoporosis, sclerodermia-like signs, flat feet, tendency toward diabetes mellitus and parental consanguinity. Hyaluronic acid was not detected in the urine. To the best of our knowledge, this seems to be the 30th report describing the association of malignancy with Werner's syndrome in Japan; besides, only one other case of bladder cancer in Werner's syndrome has been reported to date in the world.

Adult↗
PubMed1986

An improved colorimetric assay for interleukin 2.

Mosmann's method for measuring the number of viable cells with a tetrazolium salt, 3-(4,5-dimethylthiazol-2-yl)-2,5-di-phenyltetrazolium bromide (MTT), was modified to make it possible to measure a large number of interleukin 2 (IL-2) samples at one time with less labor and more accuracy. Each step of the method was examined in detail and modified (the modified MTT method). An IL-2-dependent mouse natural killer cell line, NKC3, was used as an indicator cell line. The incubation period before adding MTT was reduced to 24 h, A solution of 10% sodium dodecyl sulfate-0.01 N HCl was used to dissolve the MTT formazan produced. We have compared the values obtained by the modified MTT method and the conventional [3H]thymidine method (3H-TdR method), and confirmed that the estimates of IL-2 content were almost equal. The variation of IL-2 content measured by both methods was within 5% in terms of the standard error.

Cells, Cultured↗
PubMed1986

Functional and molecular analysis of three distinct HLA-DR4 beta-chains responsible for the MLR between HLA-Dw4, Dw15, and DKT2.

Differences in structure and function of HLA-class II molecules between HLA-DR4-related HLA-D specificities HLA-Dw4, Dw15, and DKT2 were investigated. Anti-HLA-DR framework monoclonal antibody HU-4 completely inhibited the one-way mixed lymphocyte reaction (MLR) between these specificities. HU-4 precipitated a monomorphic alpha-chain and a polymorphic beta-chain of human class II molecules from each B lymphoblastoid cell line (BLCL) homozygous for these three HLA-D specificities. We established IL 2-dependent T cell lines specific for streptococcal cell wall (SCW) antigen from peripheral blood lymphocytes (PBL) from four DR4-positive donors: an HLA-Dw4/DKT2 heterozygote, an HLA-Dw4/Dw12 heterozygote, an HLA-DKT2/D-blank heterozygote, and an HLA-Dw15/D-blank heterozygote. These T cell lines showed a proliferative response to SCW antigen in the presence of autologous or allogeneic antigen-presenting cells (APC) when T cell donors and APC donors shared at least one of the HLA-D specificities. This cooperation between the T cell line and APC was completely blocked by HU-4. We conclude from these data that the T cells could distinguish three distinct DR4 molecules expressed on APC of HLA-Dw4, Dw15, and DKT2 as restriction molecules at the presentation of SCW antigen.

Antibodies, Monoclonal↗
PubMed1986

Characteristics of murine non-specific killer cells induced in vivo by recombinant human interleukin-2.

We have examined the induction of murine non-specific killer cells in vivo and in vitro by purified recombinant human interleukin-2 (rIL-2), and compared their characteristics with respect to killing ability, cell surface phenotypes, and antibody-dependent cell-mediated cytotoxicity (ADCC). C57BL/6 spleen cells cultured with rIL-2 were remarkably cytotoxic against a variety of tumour cells in a 4-hr 51Cr-release assay. Treatment with various antibodies (anti-Thy 1, anti-Lyt 1, anti-Lyt 2, and anti-asialo GM1) plus complement (C) showed that anti-Thy 1 or anti-asialo GM1 antibody plus C removed a majority of killer activity (80% and 66%, respectively). In addition, an increase in ADCC was detected in the spleen cells cultured with rIL-2. These ADCC effector cells were indistinguishable from non-specific killer cells by the cell surface phenotypes. A single administration of rIL-2 in vivo induced only transient and marginal enhancement of non-specific killer activity of spleen cells in C57BL/6 mice. On the other hand, when 10 micrograms of rIL-2 were administered daily by bolus to C57BL/6 mice, the activity increased gradually for about 10 days and reached a plateau. This enhanced non-specific killer activity rapidly decreased and returned to normal by 72 hr after the administration was stopped. The non-specific killer cells induced in vivo in this manner were not only greatly cytotoxic against natural killer (NK)-sensitive tumour cells but were also significantly cytotoxic against NK-resistant tumour cells. Most of the killer activity (more than 90%) was specifically removed by treatment with anti-Thy 1 or anti-asialo GM1 antibody plus C. An increase in ADCC was detected concurrently with an increase in non-specific killer activity in vivo, and both effector cells were indistinguishable by their cell surface phenotypes. These results indicate that a majority of non-specific killer cells induced both in vivo and in vitro by rIL-2 have some common features. Our results also suggest that these cells belong to the same lineage as NK cells, although they are thought to be at different stages from resident NK cells.

Animals↗
PubMed1985

Production of cytotoxic factor(s) in human T cell lines transformed by a human retrovirus.

Human T cell lines, MT-2, TCL-Ter, TCL-Haz, and TCL-Kan which were transformed by a human retrovirus, constitutively produced cytotoxic factor(s) (CF) in the culture supernatants. In these cell lines, MT-2 produced the largest amount of CF. The amount of CF produced by MT-2 was 9-10 or 3-4 times larger than that produced by a human B cell line, RPMI 1788, or normal peripheral blood leukocytes stimulated with mitogens and phorbol ester. The kinetics of the production by MT-2 was similar in media with and without serum. The activity was stable at 56 degrees C for 30 min but was lost at 80 degrees C for 30 min and at pH 2 for 20 hr. On gel filtration, the molecular weight of the factor produced by MT-2 was approximately 90,000. On isoelectric focusing, the activity was recovered in the fraction at pH 6.5-7.0.

Cell Line↗
PubMed1985

Monoclonal antibodies to human interferon-gamma. I. Antibodies to a synthetic carboxyl-terminal peptide.

Two types of hybridomas secreting monoclonal antibodies (MAB) against human interferon-gamma (HuIFN-gamma) were obtained by somatic cell hybridization between mouse myeloma P3U1 cells and spleen cells from BALB/c mice immunized with a conjugate of a synthetic carboxyl-terminal peptide (residues 131-146) of HuIFN-gamma and bovine thyroglobulin. One of the antibodies bound to recombinant HuIFN-gamma produced in E. coli as well as to natural HuIFN-gamma, while the others bound only to recombinant HuIFN-gamma. These 2 types of MAB did not neutralize the anti-viral activity of HuIFN-gamma. They were useful for effectively purifying recombinant HuIFN-gamma and quantitatively determining it by an enzyme-linked immunosorbent assay.

Animals↗
PubMed1985

Establishment of hybridomas secreting human monoclonal antibodies against tetanus toxin and hepatitis B virus surface antigen.

Mouse-human heterohybrids (M X H) were constructed and compared with other cell lines (human or mouse) as parental cells to obtain hybrids secreting human monoclonal antibody (MoAb). One of the M X H lines, HM-5, was far superior to the others and useful for establishing hybrids secreting human MoAb. Using HM-5 as a parental cell line, we have obtained 2 hybrids secreting human anti-tetanus toxoid MoAb with neutralizing activity and a hybrid secreting human anti-hepatitis B virus surface antigen (HBsAg) MoAb which recognizes the a-determinant of HBsAg.

Animals↗