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Biomedical subjects

M Kuroki

Publications and source records attributed to M Kuroki.

At least 127 records · Page 7Linked to original sources
PubMed1994

Characterization of a species of non-specific cross-reacting antigen (NCA) expressed by human monocytic cell lines: structure and expression during cell differentiation.

It has been documented that human monocytes/macrophages are reactive with antibodies directed to carcinoembryonic antigen (CEA) and non-specific cross-reacting antigens (NCAs), a group of glycoproteins antigenically cross-reactive with CEA, yet the molecules responsible for this antigenic activity have not been fully clarified. In the present study, among 7 myelomonocytic cell lines tested, 2 monoblastoid lines, U-937 and THP-1, were found to express NCA-50/90, a glycosylphosphatidylinositol-anchored cell-adhesion molecule chiefly expressed on granulocytes. The 2 cell lines showed a reaction pattern with 5 distinct anti-CEA and anti-NCA monoclonal antibodies, similar to that of CHO transfectants expressing recombinant NCA-50/90. Immunoprecipitation and SDS-PAGE analyses identified glycoproteins of about 95 and 55 kDa in U-937 and THP-1 cells, respectively. Deglycosylation of the 2 antigens with N-glycanase gave the same apparent molecular mass of about 45,000, which was also the same as that of the deglycosylated form of the recombinant NCA-50/90. Upon Northern-blot analysis, only one band of approximately 2.5 kb was detected in both cell lines with a cDNA probe for NCA-50/90, which has a broad specificity to the CEA gene family members. cDNA cloning demonstrated that the 2.5-kb clones encode the peptide of NCA-50/90. The expression of NCA-50/90 by U-937 and THP-1 was down-regulated at both the protein and mRNA levels during cell differentiation from monoblastoid to monocyte/macrophage-like cells induced by stimulation with phorbol 12-myristate 13-acetate. Our observations suggest that NCA-50/90 is a differentiation antigen of cells of the monocyte/macrophage lineage as well as of the granulocyte lineage.

Antigens, Differentiation, Myelomonocytic↗
PubMed1994

Radioimmunoscintigraphy of colorectal cancer with technetium-99m-labeled murine anti-carcinoembryonic antigen monoclonal antibody in athymic nude mice.

Technetium-99m(Tc-99m) is an ideal radionuclide for clinical use. A murine monoclonal antibody (Mab) designated F33-104 binds to specific parts of carcinoembyronic antigen (CEA). In the present study, intact Mab F33-104 was labeled with Tc-99m, and the immunoreactivity and biodistribution of Tc-99m-labeled F33-104 were studied in athymic nude mice bearing human colorectal cancer xenografts. Mab F33-104, reduced under optimal conditions, was quickly and stably tagged with Tc-99m without loss of immunoreactivity. Higher tumor uptake of Tc-99m-labeled F33-104 was noted in the biodistribution, resulting in a higher localization index and specific-to-non-specific tumor ratio than those of radioiodinated F33-104. These results suggest the potential of Tc-99m-labeled Mab F33-104 for the radioimmunoimaging of colorectal cancer.

Animals↗
PubMed1994

Passive immunisation against experimental salmonellosis in mice by orally administered hen egg-yolk antibodies specific for 14-kDa fimbriae of Salmonella enteritidis.

Chickens were immunised with a preparation of purified 14-kDa fimbriae of Salmonella serotype Enteritidis (SEF 14) to raise egg-yolk antibodies for protection trials in mice against subsequent challenge-exposure with the homologous strain of Enteritidis. A pronounced specificity of egg-yolk antibodies against the 14-kDa fimbrial antigen was demonstrated by Western blotting analysis. Passive antibody protection was evaluated in a mouse model of experimental salmonellosis: 79 mice (CD 1 strain) were challenged orally with 2 x 10(10) cfu of Enteritidis. Test mice treated with SEF-14 antibodies (titre = 128) had a survival rate of 77.8% compared to 32% survival in control mice fed normal egg-yolk antibodies (titre < 10) (p < 0.01). In-vitro adhesion of Enteritidis to mouse intestinal epithelial cells was reduced by anti-fimbrial antibodies. An indirect immunofluorescence method demonstrated the localisation of Enteritidis along the villous margins of the small intestine of control mice, whereas in test mice adherent bacteria were not detected. Results suggest that 14-kDa fimbriae may influence, enhance or contribute to the overall adhesive properties of Enteritidis and that egg-yolk antibodies directed against these fimbriae may have played a substantial role in protection, possibly by minimising bacterial colonisation and invasion during the early stages of infection.

Administration, Oral↗
PubMed1994

Cushing's disease associated with adrenal myelolipoma, adrenal calcification and thyroid cancer.

A 51-year-old woman with Cushing's disease associated with adrenal myelolipoma is reported. A further characteristic feature was the coexistence of bilateral adrenal calcification and thyroid cancer. Previously several cases of adrenal myelolipoma associated with endocrine dysfunction were reported. The combination of Cushing's disease and adrenal myelolipoma has only been described in two cases of recurrent Cushing's disease but never in an initial occurrence of Cushing's disease. Continued stimulation by excessive adrenocorticotropic hormone (ACTH) not only developed adrenal hyperplasia but also might be involved in the pathogenesis of adrenal myelolipoma.

Adrenal Gland Neoplasms↗
PubMed1994

A rapid colorimetric assay for carcinoembryonic antigen (CEA)-mediated cell adhesion and analysis of CEA domains involved in the adhesion.

A colorimetric microadhesion assay that allows the quantitative determination of carcinoembryonic antigen (CEA)-mediated homophilic cell adhesion to CEA immobilized on 96-well polyvinyl chloride plates is described. Chinese hamster ovary (CHO) cells transfected with a full-length CEA cDNA were used as indicator cells. After dislodging nonadherent cells, specifically bound cells were quantified by a colorimetric analysis based on the ability of live cells to reduce the dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) to a blue formazan product. The domains of CEA responsible for the homophilic cell adhesion were analyzed by inhibition assays using anti-CEA monoclonal antibodies whose reactive domains were already known. The involvement of domain N and possibly subdomain A3 of CEA in the homophilic cell adhesion has been suggested.

Animals↗
PubMed1994

[Mediastinal lymph node dissection in left lung cancer].

It is usually impossible to perform a complete systemic mediastinal lymph node dissection in left-side pulmonary carcinomas because the aortic arch gets in the way. The purpose of this study was to determine if incomplete lymph node dissection influences late mortality. We retrospectively analyzed 222 patients who had complete resection of non-small-cell lung cancer, 141 on the right lung and 81 on the left lung. There were 155 men and 67 women. They ranged in age from 35 to 78 years. 146 patients were in Stage I, 41, in the Stage II and 35, in the Stage III A, except for T3 diseases. The 5-year survival rates of left lung cancer were 82% and 35% in the Stage I group and the Stage II group, respectively. There was no difference when compared with the corresponding groups with right lung cancers. The 3-year survival, however, was 0% in the Stage III A group with left lung cancer excluding T3 diseases; this was significantly lower than that of right lung cancer (p < 0.01). The results recommend extended mediastinal lymph node dissection on the left-side squamous cell carcinoma to improve the survival of patients with left-side N2 diseases, when the tracheobronchial lymph nodes are involved.

Adult↗
PubMed1993

Determination of the specificities of monoclonal antibodies recognizing members of the CEA family using a panel of transfectants.

Carcinoembryonic antigen (CEA), one of the most clinically important tumor markers, is mainly used in the post-surgical surveillance of patients with colorectal carcinomas. CEA belongs to a large protein family, which includes cross-reacting antigens, e.g., non-specific cross-reacting antigens (NCAs) and biliary glycoprotein (BGP) as well as pregnancy-specific glycoproteins (PSGs). The genes encoding these proteins can be subdivided into the CEA and PSG subgroups. The members of the subgroups share antigenic determinants and show high similarity in amino-acid sequences. Their derived secondary structures show them to belong to the immunoglobulin superfamily. Due to the close relationship of the members of the CEA subgroup, it is very difficult to distinguish between the individual members with MAbs. Here we have used flow cytometric analysis of transfectants expressing individual members of the CEA subgroup as an alternative approach to determine the specificities of 13 MAbs. This allows us to examine the specificities of these antibodies for members of the CEA family, even of those which have not yet been characterized at the protein level. In addition, binding of the MAbs to NCAs expressed by polymorphonuclear cells (PMN) was tested by Western-blot analysis, immunoprecipitation and flow cytometry. Four antibodies bound exclusively to NCA-50/90 and one MAb (80H3) only to NCA-95. MAb 4/3/17 recognizes CEA and BGP on the surface of transfectants and NCA-160 from granulocytes. We assume that NCA-160 is a product of the BGP gene. On granulocytes, which do not express CEA, MAb 4/3/17 is specific for NCA-160 (BGP). Mutual inhibition of the MAbs binding to NCA-50/90 revealed 3 different epitope groups.

Antibodies, Monoclonal↗
PubMed1993

Multiple neutralizing B-cell epitopes of human T-cell leukemia virus type 1 (HTLV-1) identified by human monoclonal antibodies. A basis for the design of an HTLV-1 peptide vaccine.

We have generated 153 human mAb reacting with natural envelope glycoprotein-gp46 of human T-cell leukemia virus type-1 (HTLV-1) by the EBV-transformation of B lymphocytes obtained from patients with HTLV-1-associated myelopathy (HAM)/Tropical spastic paraparesis (TSP). Twenty-four of these mAb had neutralizing activity of HTLV-1 as determined by an HTLV-1-induced syncytium formation inhibition assay in vitro. The reactivity of these neutralizing mAb was studied by using 9 different synthetic peptides covering immunodominant regions of the gp46. Thirteen out of these 24 neutralizing mAb reacted with gp46 peptide 175-199, whereas one mAb reacted with gp46 213-236 and another one with gp46 288-317. The other 9 neutralizing mAb did not react with any of these peptides. Fine epitope mapping of the mAb reacting with gp46 peptide 175-199 revealed the presence of 4 distinct neutralizing B-cell epitopes on this region; (1)187-193, (2)191-196, (3)193-199, and (4) continuous conformational B-cell epitope. The competitive antibody-binding inhibition experiments by soluble phase synthetic peptides showed that the binding activity of these neutralizing mAb to the corresponding synthetic peptides is equal to or a little lower than that to native gp46 protein, suggesting that synthetic peptides can form structure very similar to the neutralizing epitopes on native gp46 protein. The present study is the first systematic demonstration of multiple neutralizing B-cell epitopes of HTLV-1 in human HTLV-1 infection. It would be possible to prepare a synthetic peptide vaccine against HTLV-1 based on these newly identified multiple linear neutralizing B-cell epitopes of HTLV-1.

Amino Acid Sequence↗
PubMed1993

An enzyme immunoassay for carcinoembryonic antigen (CEA) with homogeneous reactivity to different CEA preparations and low cross-reactivity with CEA-related normal antigens.

A new sandwich-type solid-phase enzyme immunoassay (EIA) for carcinoembryonic antigen (CEA) was established by using two selected monoclonal antibodies (MAbs). One MAb, F82-61, which is immobilized on polystyrene beads, reacts with an epitope present on the N-terminal domain (N) of the CEA molecule and the other, F11-39, which is conjugated to horseradish peroxidase (HRP), recognizes an epitope present on the C-terminal domain (B3) of the CEA molecule. The assay consists of incubating 0.05 ml of test serum both with F82-61-coated beads and HRP-labeled F11-39 at room temperature for 2 h. The assay system, referred to as New EIA, showed very homogeneous reactivity with purified CEA preparations from different tumors and could discriminate CEA from four CEA-related normal antigens tested; nonspecific cross-reacting antigen (NCA), NCA-2, normal fecal antigen-1 (NFA-1) and NFA-2. The assessment of technical qualities, such as reproducibility, recovery and dilution tests, demonstrated the excellent performance of New EIA. Serum samples (n = 604) from patients with malignant or non-malignant disease, as well as from healthy individuals, were analyzed by New EIA and by two commercial CEA immunoassays which both showed heterogeneous reactivity with different CEA preparations and reacted to a greater or lesser extent with NCA-2 and NFA-2, and it was found that New EIA significantly increased the sensitivity and specificity of tumor diagnosis as compared with the commercial assays.

Animals↗
PubMed1993

Production of anti-cardiolipin antibody in AKR/J mice with streptozocin-induced insulitis and diabetes.

We herein report that anti-cardiolipin antibodies (ACA) were detected in AKR/J mice treated with multiple low doses of streptozocin (STZ)-induced insulitis and diabetes. Daily intraperitoneal (i.p.) injections of 40 mg/kg body wt. of STZ for five consecutive days in the AKR/J mice resulted in hyperglycemia and mononuclear cell infiltrations of islets (insulitis). ACA appeared on day 14, when hyperglycemia began to occur, at a rate of 13.3% (4/30). The rate increased to 83.3% (25/30) on day 21, when diabetes developed, and then fell to 10% (3/30) on day 28. Neither the diabetic AKR/J mice treated with a single high dose of STZ (200 mg/kg body wt.) nor the non-diabetic insulitis free Balb/c mice and B10.S(9R) mice treated with multiple low doses of STZ (40 mg/kg body wt.) produced ACA. The IgG subclass of the ACA belonged mainly to IgG2a. These findings suggest that ACA are produced in association with the development of insulitis, but not induced by either hyperglycemia or STZ.

Animals↗
PubMed1993

Passive protection against bovine rotavirus-induced diarrhea in murine model by specific immunoglobulins from chicken egg yolk.

Chicken egg yolk immunoglobulins (yIg) specific against bovine rotavirus (BRV) serotypes 6 (strain Shimane) and 10 (strain KK-3) were used for oral passive immunization of suckling mice against experimental BRV challenge. The protective capacity of the antibody preparation was tested using different concentrations of yIg against a challenge dose of 10(7.5) TCID50 for Shimane and 10(7.0) TCID50 for KK-3 strain. There was a significant homotypic (P < 0.05) and heterotypic (P < 0.01) protection using 160 anti-Shimane or 160 anti-KK-3 neutralizing antibody titer (NAT) compared to control mice given yIg derived from eggs of mock-immunized (control) hens. The titer of infectious BRV recovered from intestinal tissue or luminal chyme decreased with increasing homotypic yIg NAT. A decrease in degree and duration of BRV antigen localization in the villus epithelial lining was observed in mice treated with homotypic yIg at optimum dose for prevention of diarrhea. The NAT in sera of challenged mice increased with decreasing NAT in the yIg given before challenge suggesting that protection was dose-dependent. The present findings indicate that a passive protection could be achieved by the use of yIg against BRV-induced diarrhea in this murine model.

Animals↗
PubMed1993

Effective purification of nonspecific cross-reacting antigens with phosphatidylinositol-specific phospholipase C.

Two molecular species of nonspecific cross-reacting antigens, NCA-90 and NCA-50 with mol. wts. of 90,000 and 50,000, respectively, were effectively extracted with phosphatidylinositol-specific phospholipase C (PI-PLC) from human lung tissues, followed by extraction with perchloric acid, immunoaffinity chromatography with anti-NCA adsorbent, and gel filtration on a TSK G3000SW column. The yields of NCA were about 2 times more than those obtained by the usual method without PI-PLC. Addition of 0.05 unit of PI-PLC to 1 g of lung tissue and incubation at 37 degrees C for 1 h with continuous shaking seem to be practically sufficient for NCA extraction. The immunochemical properties of the NCAs thus obtained were found to be identical to those of NCAs obtained by the ordinary method.

Antigens↗
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

Transient rise in serum interleukin-8 concentration during acute myocardial infarction.

OBJECTIVE: To determine whether interleukin-8 (IL-8, a potent activator of neutrophils) is involved in tissue injury during ischaemia and reperfusion in patients with acute myocardial infarction. SETTING: Teaching hospital. SUBJECTS: Five consecutive patients with acute Q-wave myocardial infarction, two patients with stable angina who underwent elective percutaneous transluminal coronary angioplasty, and 10 normal controls. MAIN OUTCOME MEASURE: Serum IL-8 concentration measured by enzyme linked immunosorbent assay (ELISA) over time (every four, eight or 12 hours for 36-72 hours). RESULTS: All five patients with acute myocardial infarction had a transient but significant rise in serum IL-8 concentration (13-1100 ng/l) within 22 hours after the onset of symptoms, whereas IL-8 was not detected in any of the samples from patients with angina pectoris or normal controls. One patient who died of pump failure and two patients who had mild congestive heart failure showed the highest values (1100, 920, and 190 ng/l respectively). CONCLUSIONS: Serum IL-8 concentration showed a transient rise during the very early phase of acute myocardial infarction. In combination with several recent lines of evidence indicating the importance of injurious activities of neutrophils as a cause of tissue damage in acute myocardial infarction and the potent stimulation of neutrophils by IL-8, these results strongly suggest that IL-8 is important in the development of myocardial injury in acute myocardial infarction.

Adult↗
PubMed1993

Subclinical carpal tunnel syndrome in acromegaly.

Median nerve conduction was studied in 16 acromegalic patients with asymptomatic carpal tunnel syndrome (CTS) to examine the incidence of subclinical CTS. Thirteen patients (81%) and 23 hands (72%) demonstrated subclinical CTS, 10 bilaterally and three unilaterally in the dominant hand. The incidence reflects the greater sensitivity of the inching method for detecting focal conduction abnormalities. Two of three patients without subclinical CTS showed normal plasma somatomedin-C concentration despite growth hormone hypersecretion. Following adenomectomy, nerve conduction normalized in only six hands (26%). The postoperative persistence of the conduction delay implies that irreversible narrowing of the carpal tunnel rather than reversible soft tissue edema is the principal cause of CTS associated with acromegaly.

Acromegaly↗
PubMed1993

Research note: avidity of chicken yolk antibodies to enterotoxigenic Escherichia coli fimbriae.

The yolk antibodies from chickens and the serum and colostrum antibodies from cows were obtained after immunization of these animals with inactivated bacterin or purified K99 fimbriae from enterotoxigenic Escherichia coli (ETEC). The avidity of anti-K99 fimbriae antibodies produced from either chickens or cows was measured by competitive binding assay of ELISA. The yolk antibodies competed strongly with the serum and colostrum antibodies from immunized cows and inhibited 40 to 80% of the binding of these antibodies. Results demonstrate that the avidity of antibodies obtained from immunized chickens compares with that obtained from immunized cows. Thus, the yolk antibody from immunized chickens, aside from its use for prophylaxis against some infectious diseases, may also serve as effective ligand for purification of biologically active substances such as fimbrial antigens by affinity chromatographic procedures.

Animals↗