PubMed Health⌕ Search

Biomedical subjects

H Kanda

Publications and source records attributed to H Kanda.

At least 109 records · Page 6Linked to original sources
PubMed1995

Determination of growth fraction index in mammary carcinoma using MIB-1 monoclonal antibody: estimation of whole tumor proliferative potential using biopsy specimens.

We labeled the Ki-67 antigen in mammary carcinomas, using a MIB-1 monoclonal antibody, to evaluate the usefulness of MIB-1 Ki-67 Growth Fraction Indices (GFI; number of Ki-67 positive cells/total number of cells) of biopsy specimens in estimating the proliferative potential of the carcinomas. Formalin-fixed paraffin sections prepared from biopsy material, primary tumors, and axillary lymph nodes of ten invasive mammary carcinomas were chosen for immunohistochemical study. Bound antibody was detected using the avidin-biotin-complex peroxidase method. The GFI of the resected mammary carcinomas was similar to the estimated values based on the GFI of the biopsy specimens. The GFIs of the metastatic nodes in seven of the carcinomas were similar to those of the primary carcinomas, whereas two carcinomas yielded significantly different GFIs in the metastatic foci. These results suggest that the GFI of a mammary carcinoma biopsy specimen may reflect the proliferative ability of the whole carcinoma.

Adult↗
PubMed1994

Construction and expression of chimeric antibodies by a simple replacement of heavy and light chain V genes into a single cassette vector.

A novel vector pMH-gpt, which is proved useful for cloning mouse immunoglobulin heavy and light chain V genes and for expressing mouse-human chimeric antibody, was constructed. The vector contains human genomic C gamma 1 and C kappa genes, cloning sites for immunoglobulin V region genes, murine Ig promoters, a human Ig heavy chain enhancer, and the selection marker gene Eco-gpt. Because VH and V kappa genes can be cloned into a single vector, a chimeric antibody gene is easily constructed by this simple insertion procedure. The usefulness of the vector was confirmed by construction of two mouse-human chimeric antibodies. Mouse monoclonal antibody (MAb) 196-14 recognizes the ovarian cancer-associated antigen (CA125), and MoAb 2-18 reacts with carcinoembryonic antigen (CEA). Mouse-human chimeric 196-14 and 2-18 antibodies were readily constructed and efficiently produced in a mouse myeloma cell line by utilizing the vector. Both chimeric antibodies retained binding activity to their respective antigens. In biodistribution and immunoscintigraphy studies, specificity of radiolabeled chimeric 196-14 antibody was identical to that of its murine counterpart and significant accumulation at the tumor site was observed. The pMH-gpt vector is useful for constructing and producing mouse-human chimeric antibodies.

Amino Acid Sequence↗
PubMed1994

Importance of early gamma interferon production in Propionibacterium acnes-induced resistance to Toxoplasma gondii infection in mice.

Treatment of mice with heat-killed Propionibacterium (P.) acnes conferred transient protection against Toxoplasma infection. To investigate the mechanism of this nonspecific resistance, the production of gamma interferon (IFN-gamma) by P. acnes-injected mice was evaluated in comparison with that by noninjected controls upon infection with Toxoplasma. Mice pretreated with this bacterium produced significantly more IFN-gamma than that produced by control mice up to 24 hr of infection. A single injection of anti-IFN-gamma MAb on day 0 but not later than day 3 of infection resulted in a total abrogation of the resistance conferred by P. acnes. Likewise, daily injection of cyclosporin A (Cs-A), a potent inhibitor of T cell function, during the first 3 days of Toxoplasma infection severely exacerbated the infection, in accordance with a marked suppression of the early IFN-gamma production. In contrast, the administration of Cs-A for 3 consecutive days starting at day 4 had no significant consequence on P. acnes-induced anti-toxoplasma resistance, while it reduced greatly the ability of P. acnes-injected mice to produce IFN-gamma in the later phase of infection. Moreover, no significant increase in mortality and suppression of IFN-gamma production was noted in mice receiving anti-asialo GM1 antibody. These results suggest that the early IFN-gamma production by T cells is an essential event for the establishment of P. acnes-induced anti-toxoplasma resistance in mice.

Animals↗
PubMed1994

Analysis of the genes encoding the variable regions of human IgG rheumatoid factor.

OBJECTIVE: To better understand the immunoglobulin variable (V) region repertoire of rheumatoid factors (RF). METHODS: We characterized the heavy (H) and light (L) chain gene segments utilized in a monospecific IgG RF secreting hybridoma (AEE111F) which were derived from a patient with rheumatoid arthritis (RA). The hybridoma was established by fusion of a mouse myeloma cell line with bone marrow derived mononuclear cells from a patient with RA. First strand complementary DNA (cDNA) was generated and used for a polymerase chain reaction amplification of the H and L chain V domains. The amplified V domains were sequenced and compared with an extensive database of germline and cDNA V gene segments. RESULTS: The VH sequence was found to be 96% homologous to a previously described fetal VH3 cDNA (60P2). The VL sequence was also highly homologous to the previously described V lambda II gene (96%) derived from a patient with systemic lupus erythematosus which correlated with an 8.12 idiotype (Id), and to an antibacterial antibody against the Haemophilus influenzae type b capsular polysaccharide (94.7%). CONCLUSION: The overlap among this RF VL gene and the 2 reported V lambda sequences of antibodies that expressed anti-DNA related Id and an environmental pathogen specificity suggests that a part of the IgG RF isolated from patients with RA may thus be derived from the physiological natural antibody repertoire during an abnormal immune response and then develop high affinity, monospecific RF by the selection of an antigen driven mechanism.

Amino Acid Sequence↗
PubMed1993

Molecular cloning of a human monoclonal antibody reactive to ganglioside GM3 antigen on human cancers.

In this study we report the characterization of a human monoclonal antibody (HuMab), L612, that reacts with ganglioside GM3 and has therapeutic application for the treatment of human neoplasms, particularly melanoma. A permanent IgM-secreting Epstein-Barr virus-transformed B-cell line L612 was established. L612 HuMab bound specifically to neoplastic cell lines in culture and in tissue biopsy specimens such as melanoma, colon, breast, and lung cancer. The antibody did not bind to normal cells or biopsy tissue. HuMab L612 showed the highest reactivity to melanoma cells, particularly to those with high concentrations of GM3. Immunostaining on high-performance thin-layer chromatography plates demonstrated that L612 HuMab bound to GM3 purified from melanoma cells. Removal of the sialic acid from GM3 abolished antibody binding. HuMab L612 also reacted to GM4 purified from egg yolk, indicating that it recognizes an NeuAc alpha 2-3 galactose antigen determinant. HuMab L612 heavy and light chains were sequenced and determined to belong to the mu heavy chain variable subgroup III and kappa chain variable subgroup IV families, respectively. The studies indicate that the L612 HuMab has significant therapeutic potential for a wide variety of human cancers.

Adenocarcinoma↗
PubMed1993

A human/mouse chimeric monoclonal antibody against CA125 for radioimmunoimaging of ovarian cancer.

Murine monoclonal antibody 196-14 recognizes the ovarian-cancer-associated antigen CA125, but the epitope it recognizes is different from that of monoclonal antibody OC125. We developed a human/mouse chimeric 196-14 using the variable regions of the murine 196-14 and human heavy-chain (gamma 1) and light-chain (kappa) constant regions. Cell binding and competitive inhibition assays using chimeric 196-14 labeled with 125I, 111In or 99mTc demonstrated that the in vitro immunoreactivity of the chimeric antibody was identical to that of the parental murine monoclonal antibody. However, in mice bearing human ovarian cancer xenografts, the clearance from blood was faster and absolute levels of accumulation in the tumor were lower for the 125I-labeled or 99mTc-labeled chimeric antibody than for the murine antibody labeled with the corresponding radionuclides. The tumor-to-blood radioactivity ratio was not significantly different between the chimeric antibody and the murine antibody, regardless of the radionuclide used for labeling. Chimeric antibody 196-14 labeled with 131I, 111In or 99mTc is promising for the radioimmunoimaging of ovarian cancer.

Adenocarcinoma↗
PubMed1993

Construction and expression of two mouse-human chimeric antibodies with high specificity and affinity for carcinoembryonic antigen.

We have previously reported that a group of monoclonal antibodies (MAbs) to carcinoembryonic antigen (CEA), designated Group F MAbs, are able to discriminate CEA in tumor tissues from the CEA-related normal antigens and that CEA assay systems utilizing at least one Group F MAb show the improved cancer diagnosis. In this study, we cloned the genes coding for two Group F MAbs (F11-35 and F11-39) and deduced the amino acid sequences of the variable regions for their heavy and light chains. The variable region for the heavy chain of F11-35 contained a possible N-glycosylation site (Asn/Asp/Thr) at amino acid positions 89-91. Then, we constructed two mouse-human chimeric antibodies by using the F11-35 and F11-39 variable region genes of heavy and light chains (VH and V kappa) and human heavy and light chain constant region genes (gamma 1 and kappa) derived from a human plasma cell leukemia line (ARH77). The chimeric gene constructs were sequentially co-transfected into murine non-Ig-producing myeloma (P3-U1) or hybridoma (Sp2/0) cells by electroporation. The resulting chimeric heavy chain of F11-35 showed a slightly but significantly higher molecular weight than that of F11-39, but the molecular weights of their unglycosylated peptides synthesized in the presence of tunicamycin were similar, indicating the glycosylation at the possible N-glycosylation site in the variable region of the Ch F11-35 heavy chain. Both chimeric antibodies exhibited the same specificity and affinity for CEA as those of the parental murine hybridoma antibodies, respectively. Ascites production of Sp2/0 transfectomas is sufficiently high (600-900 micrograms/ml) for initial clinical studies with the chimeric antibodies.

Amino Acid Sequence↗
PubMed1993

Malignant transformation of a mouse liver epithelial cell line by transfection of an activated c-H-ras gene with a point mutation at codon 12.

In order to scrutinize the reason why in mouse liver system only activated H-ras gene with a point mutation at codon 61 but not codon 12 is frequently seen although the latter mutation is highly frequent in methylnitrosourea-induced rat mammary tumors, transforming activity of these two types of mutated H-ras gene was investigated utilizing an immortalized but not fully transformed mouse liver epithelial cell line MLE-10, established in our laboratory. MLE-10 cells were transfected with activated human c-H-ras gene having a point mutation at either codon 12 (PT24) or 61 (PSK2), together with PSV2neo, or with PSV2neo only. G418 resistant colonies, propagated separately, gave rise to 6, 3 and 6 lines respectively. All the PT24 and PSK2-transfected cell lines were growth capable in both soft agar and nude mouse subcutis, with similar growth rate and morphological features whereas none of the cell lines transfected with the PSV2neo only revealed such growth capability. The results thus revealed that c-H-ras with a mutation at codon 12 has oncogenic activity to the mouse hepatocyte, although after immortalization, at the degree similar to the same gene with a mutation at codon 61.

Animals↗
PubMed1993

[Pneumonia due to respiratory syncytial virus diagnosed by transtracheal aspiration in an adult].

A healthy-looking 44-year-old female was admitted to our hospital complaining of fever and hemosputum. The chest roentgenogram on admission showed patchy infiltrates of the segment 3 and 8 of the right lung. Laboratory studies showed a leukocyte count of 9700/microliters, erythrocytes sedimentation rate of 55 mm/hour and C reactive protein of 8.7 mg/dl. The arterial PO2 was 71.9 torr while the patient was breathing room air. Transtracheal aspiration was performed on admission, and strains and culture for bacteria, acid fast bacilli, fungi and mycoplasma were negative. Respiratory syncytial virus was isolated from transtracheal aspirates. The RSV complement fixing antibody titers rose from 1:40 to 1:16. She became afebrile on the fourth day after admission and her chest roentgenogram improved gradually. RSV infection should be considered in the differential diagnosis of atypical adult pneumonias.

Adult↗
PubMed1993

Possible association of p53 overexpression and mutation with high-grade chondrosarcoma.

Overexpression and point mutation of the p53 protein/gene was investigated in a series of chondrosarcoma by an immunohistochemical approach, and direct sequencing of the genomic DNA, respectively. In 2 of the 16 cases studied, both of which were high grade chondrosarcomas (grade III), immunodetectable p53 was identified. Histologically, one was ordinary type and the other a clear cell variant. However, no positivity was observed in the other cases including nine of low grade, ordinary type, three of low grade, clear cell type, and two of extraskeletal myxoid chondrosarcoma. Direct sequencing, following polymerase chain reaction amplification of exons 5-9 of the p53 gene in 14 cases, in which fresh materials were available, successfully demonstrated base substitution mutations in only two cases with detectable p53 overexpression on immunohistochemistry. Their details were GTC (valine) to TTC (phenylalanine) at codon 157 in exon 5, and CGT (arginine) to CAT (histidine) at codon 273 in exon 8. No mutation was detected in the other 12 cases which were negative for p53 immunostaining. These findings strongly suggest that p53 mutation plays a crucial role in the biologically aggressive subtype, and possibly in the process of tumor progression in human chondrosarcoma.

Adult↗
PubMed1993

[Hepatocarcinogenesis in terms of HGF and its receptor].

Hepatocyte growth factor (HGF) is a highly potent growth stimulator of hepatocytes and c-met proto-oncogene has recently been identified as its high-affinity receptor. Since the c-met gene expression is found in many types of cells, carcinogenic and/or transforming activity through autocline or paracline mechanism of HGF-c-met/HGFR system has become point of interest. By transfecting HGF into a unique immortalized mouse hepatocytes (MLE-10), which expresses c-met at high level, we were able to first demonstrate transforming activity of HGF by autocline mechanism.

Animals↗
PubMed1993

Hepatocyte growth factor transforms immortalized mouse liver epithelial cells.

Transforming activity of hepatocyte growth factor (HGF) was demonstrated utilizing immortalized but not fully transformed mouse hepatocytes (MLE-10). Rat HGF cDNA, expressed under the control of a cytomegalovirus promoter, was transfected together with the neomycin resistance gene (PSV2neo) into MLE-10 cells by the calcium phosphate method, and propagated G418-resistant colonies were harvested colony by colony. After checking for integration and expression of exogenous HGF, five cell lines (MLE-10-HGF-1-5) were established. Three cell lines transfected with the vector only (MLE-10-CMV-1-3) were also established in the same manner. All MLE-10-HGF cell lines grew much faster than the MLE-10-CMV and original MLE-10 cells in culture and produced large colonies in soft agar, which colony production was blocked by the addition of anti-HGF antibody to the agar. After addition of HGF, original and MLE-10-CMV lines produced colonies in soft agar. The high-HGF-production lines (MLE-10-HGF-4 and -5) also gave rise to tumors within 2 weeks when implanted into the nude mice subcutis. In contrast, all MLE-10-CMV and original MLE-10 cells were negative in these growth assays. A rough parallelism between the level of HGF expression and the growth rate in both soft agar and nude mice subcutis was evident among MLE-10-HGF cell lines. Those with higher HGF production tended to grow in a scattered fashion in culture. High-affinity HGF receptor, HGFR/met, was expressed in MLE-10 and all the derived cell lines. Since HGF and/or HGFR/met gene expression is seen in various tumors and the serum HGF level is elevated in patients with hepatic disease, the present results indicate a possible significance of HGF and its receptor system in carcinogenesis, most probably via autocrine and/or paracrine mechanisms.

Animals↗
PubMed1992

Efficient amplification of Drosophila simulans copia directed by high-level reverse transcriptase activity associated with copia virus-like particles.

The number of retrotransposon copia per genome in Drosophila melanogaster cultured cells is two to three times higher than that in D. melanogaster embryo cells. Here, we have found that the genome of the related species, Drosophila simulans, contains in cultured cells more efficiently amplified copia DNA (approximately ten fold). Furthermore, we analyzed copia virus-like particles (VLPs) prepared from D. melanogaster and D. simulans cultured cells, which contain copia RNA and reverse transcriptase (RT) activity, and thus, play a major role in copia replication. The RT activity associated with the D. simulans VLPs was 25 times higher than that associated with the D. melanogaster VLPs. Taken together with the fact that copia is believed to transpose through an RNA intermediate, these results suggest that the amplification of copia DNA should relate to copia RNA-mediated transposition, and the higher RT activity associated with the D. simulans VLPs would lead to the efficient amplification of copia DNA. In a comparison between D. melanogaster and D. simulans copia nucleotide (nt) sequences, five nt substitutions, which cause the respective amino acid changes, were found in the copia RT-coding region. Polymerase chain reaction direct sequencing showed that these five substitutions are the vast majority in each Drosophila species. The substitutions, therefore, may be responsible for the high level of the RT activity associated with the D. simulans VLPs.

Amino Acid Sequence↗