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Biomedical subjects

S Negoro

Publications and source records attributed to S Negoro.

At least 145 records · Page 8Linked to original sources
PubMed1988

Novel receptor-mediated internalization of interleukin 2 in B cells.

Novel IL-2-binding molecules (p70 and p75) mediating internalization and degradation of IL-2 were examined by employing a human B lymphoblastoid line, SKW6-4 cells. High concentrations of IL-2 induced IgM secretion in these cells through a receptor distinct from Tac antigen. The acid-wash technique revealed that more than 60% of 125I-labeled IL-2 bound to the cells became acid-unremovable in the first 30 min of incubation at 37 degrees C and degradation products of 125I-IL-2 increased after 30 min of incubation. Treatment of the cells with NaN3 buffer inhibited the appearance of acid-unremovable 125I-IL-2, suggesting that acid-unremovable 125I-IL-2 was not due to fluid-phase pinocytosis but due to internalization. Loss of labeled bands by incubation of cells with 125I-IL-2 at 37 degrees C before affinity cross-linking demonstrated that 125I-IL-2 was internalized via novel IL-2-binding molecules. These results suggest that novel IL-2-binding molecules are responsible for internalization and may mediate signal transduction in B cells in the absence of Tac antigen.

Azides↗
PubMed1988

Interleukin 2 functions through novel interleukin 2 binding molecules in T cells.

In this report, we examined whether novel interleukin 2 (IL-2) binding molecules (p70/75) are responsible for signal transduction and internalization of IL-2 in T cells by using a monoclonal antibody H-31 to Tac antigens. We found that H-31 inhibited the binding of IL-2 to Tac antigens but not novel IL-2 binding molecules. Scatchard plot analysis revealed that in the presence of H-31, intermediate affinity sites (Kd = 1 to 1.5 nM) were detectable and the number of them was similar to that of high affinity IL-2 receptor (IL-2R) (Kd = 10 to 15 pM) in the absence of H-31. Furthermore, the kinetics of endocytosis of IL-2 via p70/75 showed the same pattern as via high affinity IL-2R. Finally, high doses of IL-2 (100 to 10,000 U/ml) are required for the proliferation of T cells in the presence of H-31, whereas in the absence of H-31, physiologic doses of IL-2 (1 to 100 U/ml) induced the proliferation. These results taken together suggest that novel IL-2 binding molecules are related to signal transduction of IL-2 and that Tac antigens are essential for constructing of high affinity IL-2R, although Tac antigens may not be responsible for signal transduction.

Antibodies, Monoclonal↗
PubMed1988

Age-related changes of proliferative response, kinetics of expression of protooncogenes after the mitogenic stimulation and methylation level of the protooncogene in purified human lymphocyte subsets.

Proliferative responses of highly purified T and B cells from aged persons to the combined stimulation with ionomycin and PMA were more significantly reduced than that from young ones although the degree of the age-related reduction was more significant in T cells than in B cells. In B cells, the levels and kinetics of c-myc gene expression after the stimulation were comparable between aged and young groups. In T cells, the maximum level of c-myc gene expression after the stimulation was comparable between the two age groups but the rate of reduction of c-myc mRNA was significantly retarded in the aged. The results of nuclear run on transcription assay showed the reduction of the rate of c-myc mRNA degradation seemed to be the cause. The levels and kinetics of c-myb gene expression in either T or B cells were comparable between the two age groups. We further examined the level of methylation of Xho I site of c-myc gene. The level of the methylation was significantly lower in the aged T cells and more significant in aged CD 8 positive T cells although that in aged B cells was comparable to that in young ones. The relation between a reduced proliferation, a retarded rate of c-myc mRNA degradation and reduction of methylation level of c-myc gene was discussed.

Aging↗
PubMed1988

Thermostable peroxidase from Bacillus stearothermophilus.

A peroxidase from Bacillus stearothermophilus was purified to homogeneity. The enzyme (Mr 175,000) was composed of two subunits of equal size, and showed a Soret band at 406 nm. On reduction with sodium dithionite, absorption at 434 nm and 558 nm was observed. The spectrum of reduced pyridine haemochrome showed peaks at 418, 526 and 557 nm; the reduced minus oxidized spectrum of pyridine haemochrome showed peaks of 418, 524 and 556 nm with a trough at 452 nm. These results indicate that the enzyme contained protohaem IX as a prosthetic group. The optimum pH was about 6 and the apparent optimum temperature was 70 degrees C. The enzyme was relatively stable up to 70 degrees C; at 30 degrees C it was stable for a month. The enzyme had peroxidase activity toward a mixture of 2,4-dichlorophenol and 4-aminoantipyrine with a Km for H2O2 of 1.3 mM. It also acted as a catalase with a Km for H2O2 of 7.5 mM.

Catalase↗
PubMed1988

Autoantibody to human c-myc oncogene product in autoimmune patients' sera.

Sera from autoimmune diseases including systemic lupus erythematosus, dermatomyositis, progressive systemic sclerosis and Sjögren's disease, were examined for reactivity against human c-myc oncogene product. We first found the presence of the autoantibody to human c-myc oncogene product in sera from autoimmune diseases. No significant correlation between the presence of the anti-c-myc product antibody and disease activity, clinical disease types and other autoantibodies such as antinuclear factor, anti-DNA antibody, anti-RNP antibody and anti-Sm antibody were shown in this study.

Autoantibodies↗
PubMed1988

Expression of novel interleukin 2 binding molecules and their functional roles in human B cell differentiation.

Expressions and functional roles of novel IL-2 binding molecules (p70, 75) in the differentiation of B cells into Ig secreting cells were explored by using human several B cell lines and tonsillar B cells. Affinity-crosslinking studies revealed that five of nine B cell lines expressed p70 and p75 without detectable Tac antigen (p55) expression and the expression was associated with B cell maturation. In tonsillar B cells, small high-density B cells did not express p70 and p75, whereas large low-density B cells, which were thought to be activated in vivo, expressed them. Binding assays of radiolabeled IL-2 showed that the affinity of these molecules was intermediate (kD = 1-3 nM, 700-3,000 sites/cell). Furthermore, high concentrations of IL-2 (greater than 100 U/ml) induced Ig productions in large B cells and two of five cell lines. These results taken together suggest that B cells may express novel IL-2 binding molecules, associated with B cell differentiation and differentiate into Ig secreting cells by IL-2 through novel IL-2 binding molecules.

Antigens, Surface↗
PubMed1988

[Phase II studies of a single agent and a cis-platinum-based two-drug combination in patients with non-small cell lung cancer].

Phase II studies of single agent and CDDP-based two drug combination were performed in 189 patients with inoperable non-small cell lung cancer. Six drug regimens were performed: CDDP alone, VDS alone, Epi-ADM alone, CDDP + VDS, CDDP + CPA, CDDP + ADM. The response rates were 15.4% (6/39) with CDDP alone, 8.0% (2/25) with VDS alone, 6.1% (2/33) with Epi-ADM alone, 26.7% (8/30) with CDDP + VDS, 14.3% (4/28) with CDDP + CPA, 17.6% (6/34) with CDDP + ADM and one CR was performed with CDDP + ADM. In patients with no prior chemotherapy, the response rates were 20.0% (6/30), 11.8% (2/17), 12.5% (2/16), 26.7% (8/30), 16.0% (4/25) and 25.0% (3/12), respectively. The median survival times were 25, 27, 23, 33, 25, and 45 weeks, respectively. The efficacy of CDDP in non-small cell lung cancer patients was re-confirmed, and that of CDDP + VDS, CDDP + ADM was suggested. No death due to toxicity occurred and toxicity was generally tolerable.

Aged↗
PubMed1988

[Chemotherapy of small cell lung cancer].

The recent results of chemotherapy for SCLC were reviewed in this paper. The combination chemotherapy with some highly active drugs can be summarized as follows: response rate 74-94% in limited disease (LD) and 63-90% in extensive disease (ED), complete response 39-57% in LD and 20-48% in ED, median survival 10-21 months in LD and 7-12 months in ED. To overcome drug resistance in the treatment of SCLC, non-cross resistant alternating chemotherapy has been explored. In our institute, a randomized study of continuous vs alternating regimen for SCLC was carried out from August 1982 to March 1985. This resulted in the acknowledged superiority of the alternating regimen in CR rate and the overall response rate, but no differences in survival. A current study comparing the standard chemotherapy with cyclophosphamide, adriamycin and vincristine (CAV) to alternating CAV with etoposide (E) and cisplatin (P) has suggested an advantage for alternating chemotherapy, with a statistically superior response rate and survival. The high-dose (HD) chemotherapy for SCLC is also a new strategy to improve the current treatment results. We are now studying the efficacy of HD-E (1.0-1.5 g/m2) with or without P (80-120 mg/m2) for relapsed SCLC. The result suggested that HD-E and P is an effective treatment modality as a salvage therapy. The search for new active drugs is another important way to improve the treatment results. Since 1986, a phase II study of Carboplatin has been performed in Japan. The ongoing data suggest that Carboplatin is a highly active agent against SCLC. Finally, further research will be necessary to investigate novel modalities in order to achieve a breakthrough in the current status.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

[CD antigens and the differentiation of human lymphocytes].

Many monoclonal antibodies directed against differentiation antigens expressed on human lymphocytes have been produced to study the development and functional difference of human lymphocytes. These monoclonal antibodies were classified to the group of "cluster of differentiation (CD)". We reviewed the functional roles of CD antigens on the activation, proliferation and differentiation of human lymphocytes.

Antibodies, Monoclonal↗
PubMed1988

Proto-oncogene expression and nuclear factor specifically bound to c-myc gene in peripheral blood mononuclear cells from progressive systemic sclerosis patients as the indicator of clinical activity.

In the present study, we examined the expression of various protooncogenes and the specific binding of nuclear factor to c-myc gene in peripheral blood mononuclear cells (PBMC) from progressive systemic sclerosis (PSS) patients. We demonstrated first amplified expression of c-myc and c-myb gene and the existence of a nuclear protein specifically bound to 5'-non-coding fragment of c-myc gene. We then found a positive correlation between the degree of expression and/or affinity for the c-myc gene fragment of the nuclear protein and clinical disease activity. The amount of the factor was significantly reduced along with or prior to the amelioration of clinical symptoms and laboratory abnormalities with treatment. The significance of c-myc and c-myb proto-oncogene expression and nuclear factor specifically bound to c-myc gene is discussed.

Binding, Competitive↗
PubMed1988

[Restorative effect of muroctasin, MDP-Lys (L 18), on leukopenia caused by anticancer chemotherapy in lung cancer--comparative study by envelope method].

Muroctasin, a derivative of MDP, is known to augment the number of WBC via colony-stimulating factor. Muroctasin has been expected to be promising for application to leukopenia caused by anticancer chemotherapy. When WBC decreased to less than or equal to 3,000/mm3 after the 1st course of chemotherapy, 131 patients with lung cancer, who were previously classified by chemotherapy combination, were enrolled in the study and randomized into 3 groups, 200 micrograms (H), 100 micrograms (L) and untreated control (C) groups. The patients were then subcutaneously treated once daily for 6 consecutive days. WBC and its differential count were measured on days 4, 7 and 15 after commencement of the study. WBCs in H and L groups showed greater recovery than in C group. In WBC differential count, the recovery of neutrophil was prominent in muroctasin-treated groups. A portion of immature neutrophil in bone marrow was also increased by muroctasin treatment. In the present study, the usefulness of muroctasin in leukopenia was indicated when administered at dosages of 200 micrograms for 6 days.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1988

[Studies on an appropriate intra thoracic administration of cisplatin and sodium thiosulfate in malignant pleural effusion].

Twenty-eight patients with malignant pleural effusion received instillation of cisplatin (CDDP) into the pleural cavity to examine the pharmacokinetics and side effects of CDDP Thirteen patients received high-dose CDDP (120 mg/m2-160 mg/m2) in combination with sodium thiosulfate (STS), while 15 others received CDDP alone (80 mg/m2). Total Pt and non-protein-bound Pt (free Pt) concentrations in the pleural effusion and plasma were determined by flameless atomic absorption spectrometry. In one patient, Pt concentrations of intact CDDP and STS-bound CDDP were determined using high performance liquid chromatography and flameless atomic absorption spectrometry. Instillation of CDDP at 160 mg/m2 into the pleural cavity was achieved by concurrent use of STS in the large dose (STS 20 g/m2 1 hr later, totalling 625-fold molar ratio to CDDP). When CDDP was combined with STS, there was alleviation in hematological, renal and auditory toxicity but not in nausea, vomiting or anorexia. When CDDP was instillated into the pleural cavity at 150 mg/m2 (in combination with STS equivalent to 200-fold molar ratio to CDDP), a high Pt concentration of intact CDDP could be maintained in the pleural effusion over a prolonged period of time, recording 8.80 micrograms/ml even as late as 12 hr after instillation. On the other hand nearly all of the free Pt concentration for the first 2 hr was considered to be due to intact CDDP. Once systemically administered, STS quickly moved into the pleural effusion, binding with CDDP in the pleural cavity and thus probably reducing its anti-tumor effect. STS did not greatly affect the plasma concentration of total Pt when it was administered at a 100-fold molar ratio to CDDP, yielding only p poor effect. Our findings suggest that malignant pleural effusion could be effectively treated by the instillation of CDDP 80 mg/m2 into the pleural cavity.

Aged↗
PubMed1987

c-fos expression in human skin fibroblasts by reperfusion after oxygen deficiency: a recovery change of human skin fibroblasts after oxygen deficiency stress.

A dramatic and specific induction of c-fos mRNA was observed in human skin fibroblasts in vitro culture by oxygen reperfusion after oxygen deficiency treatment. C-fos mRNA reached a maximum about 30-60 min after oxygen reperfusion and declined to basal level after 120 min. And this phenomenon was duration of oxygen deficiency-dependent, and remarkably observed for 0.5-2 hr of oxygen deficiency. More long duration of oxygen deficiency induced a decreasing tendency of c-fos mRNA overexpression due to essential and irreversible cellular damage. Thus increased c-fos gene expression might be an early event in cellular recovery process in particularly human skin fibroblasts with oxygen deficiency.

Cells, Cultured↗
PubMed1987

Heat-shock protein synthesis by human peripheral mononuclear cells from SLE patients.

Peripheral blood mononuclear cells (PBMC) from systemic lupus erythematosus (SLE) patients have heat shock protein (hsp) 70 and hsp 85 as well as the response to various temperatures of normal PBMC and are inducible for these proteins over about 5-8 levels with heat exposure in short-term culture. Synthesis of hsp 70 and hsp 85 as well as the response to various temperatures and the time course of induction were typical for mammalian cell systems. This enhancement with heat-shock treatment was blocked by actinomycin D added before heat exposure. This demonstration that hsp genes are activated in PBMC from active SLE patients without heat exposure supports the hypothesis that gene activation can serve some roles in these cells and be related to the PBMC function in SLE patients. These observations are at least correlative and consistent with a possible homeostatic function for hsps in this system.

Dactinomycin↗
PubMed1987

Cell surface membrane antigen present on neuroblastoma cells but not fetal neuroblasts recognized by a monoclonal antibody (KP-NAC8).

Neuroblastoma (NB) arises from primitive sympathetic neuroblasts in the adrenal gland or the sympathetic ganglion. NB in situ, sometimes observed in the adrenal glands of autopsied infants, is considered to be a premalignant lesion that may develop into NB. Little is understood about the morphological and biochemical changes that accompany this malignant progression. In this study, a unique monoclonal antibody, KP-NAC8, raised against a human NB cell line is described. This binds to NB cells but not to fetal neuroblasts. The antibody recognizes a Mr 200,000 surface protein on NB cells. KP-NAC8 binds to 15 of 17 human NB cell lines and all 26 fresh NB samples either from tumor tissues or from marrow aspirates involved with tumor. The antibody was found to cross-react with some other tumor cell lines, namely, Ewing's sarcoma (1 of 2), melanoma (1 of 4), lung cancer (3 of 3), and leukemia (2 of 14) cell lines. However, KP-NAC8 did not bind to any rhabdomyosarcoma (0 of 4), Wilms' tumor (0 of 4), retinoblastoma (0 of 2), glioma (0 of 4), and gastric cancer (0 of 2) cell lines examined. Among fetal tissues, KP-NAC8 did not react with normal neuroblasts in the adrenal glands of 5 fetuses. In a further study, the membrane phenotype of fetal adrenal neuroblasts was analyzed by a panel of 12 monoclonal antibodies including KP-NAC8. A comparison of the binding of the same panel of antibodies to fresh NB revealed that antibodies UJ13A, UJ127:11, PI153/3, anti-Thy-1, A2B5, BA-1, BA-2, HSAN1.2, and Leu-7 bound to both fetal adrenal neuroblasts and NB cells. Monoclonal antibodies OKIa-1 and J5 did not bind to either tissues. The only antibody that could distinguish fetal adrenal neuroblasts from NB cells was KP-NAC8. KP-NAC8 may, therefore, define a differentiation-related antigen that may prove helpful in understanding the biological nature of NB and NB in situ.

Adrenal Glands↗