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Moore RW, Rudy TA, Lin TM, Ko K, Peterson RE. Abnormalities of sexual development in male rats with in utero and lactational exposure to the antiandrogenic plasticizer Di(2-ethylhexyl) phthalate. ENVIRONMENTAL HEALTH PERSPECTIVES 2001; 109:229-37. [PMID: 11333183 PMCID: PMC1240240 DOI: 10.1289/ehp.01109229] [Citation(s) in RCA: 223] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Several members of the phthalate ester family have antiandrogenic properties, yet little is known about how exposure to these ubiquitous environmental contaminants early in development may affect sexual development. We conducted experiments to determine effects of in utero and lactational exposure to the most prevalent phthalate ester, di(2-ethylhexyl) phthalate (DEHP), on male reproductive system development and sexual behavior. Sprague-Dawley rats were dosed with corn oil or DEHP (0, 375, 750, or 1,500 mg/kg/day, per os) from gestation day 3 through postnatal day (PND) 21. Dose-related effects on male offspring included reduced anogenital distance, areola and nipple retention, undescended testes, and permanently incomplete preputial separation. Testis, epididymis, glans penis, ventral prostate, dorsolateral prostate, anterior prostate, and seminal vesicle weights were reduced at PND 21, 63, and/or 105-112. Additional dose-related effects included a high incidence of anterior prostate agenesis, a lower incidence of partial or complete ventral prostate agenesis, occasional dorsolateral prostate and seminal vesicle agenesis, reduced sperm counts, and testicular, epididymal, and penile malformations. Many DEHP-exposed males were sexually inactive in the presence of receptive control females, but sexual inactivity did not correlate with abnormal male reproductive organs. These results suggest that in utero and lactational DEHP exposure also inhibited sexually dimorphic central nervous system development. No major abnormalities were found in any of eight control litters, but DEHP caused severe male reproductive system toxicity in five of eight litters at 375 mg/kg/day, seven of eight litters at 750 mg/kg/day, and five of five litters at 1,500 mg/kg/day. These results demonstrate that the male reproductive system is far more sensitive to DEHP early in development than when animals are exposed as juveniles or adults. The effects of DEHP on male reproductive organs and sexual behaviors and the lack of significant effects on time to vaginal opening and first estrus in their littermates demonstrate that DEHP (and/or its metabolites) affects development of the male reproductive system primarily by acting as an antiandrogen. The pattern of effects of in utero and lactational DEHP exposure differed from patterns caused by other phthalate esters, and the preponderance of anterior prostate agenesis appears to be unique among all chemicals. These results suggest that DEHP acts partly by mechanisms distinct from those of other antiandrogens.
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Fujii K, Fujioka S, Kato K, Machiki Y, Kutsuna Y, Ishikawa A, Takamizawa J, Ko K, Yoshida K, Nimura Y. Resection of liver metastasis from gastric adenocarcinoma. HEPATO-GASTROENTEROLOGY 2001; 48:368-71. [PMID: 11379310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
BACKGROUND/AIMS To determine the factors influencing the prognosis of patients undergoing resection of liver metastases from gastric adenocarcinoma. METHODOLOGY Over a 10-year period, at Kiryu Kousei General Hospital, 12 patients underwent potentially curative hepatectomy for metastatic adenocarcinoma of gastric origin. Two patients were excluded from this study, one because of postoperative death and one due to insufficient follow-up. We retrospectively examined the following factors: including TNM classification of the primary tumor, disease-free interval between gastric and hepatic resection, number and maximum diameter of the metastases, histological differentiation of the metastases, and the presence of lymphocyte aggregation enclosing the metastatic lesions. Survival rates were estimated by the Kaplan-Meier method and the weighting of each factor was compared by the log-rank test. RESULTS The overall 5-year survival rate of the 10 patients was 10%. The median survival time after hepatectomy was 16.3 months, ranging from 3.1 to 245.7 months. Eight patients died of recurrent cancer and 1 died of unrelated septic shock with no evidence of cancer recurrence. Only one patient was alive without recurrence at the time of maximum follow-up. A significant survival advantage was noted in patients with disease-free interval > or = 1 year, and those with metastatic tumors < 5 cm in maximum diameter and/or enclosed by the aggregated lymphocytes, when compared with patients with disease-free interval < 1 year and those with metastatic tumors > or = 5 cm and/or directly infiltrated hepatic parenchyma. CONCLUSIONS It was suggested that hepatectomy should be attempted in patients where the disease-free interval was > or = 1 year and with metastatic nodules < 5 cm. Lymphocyte aggregation around the metastatic tumor is a good prognostic sign for long-term survival.
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Cameron BA, Gilmour K, Forster R, Ko K, Tufts BL. Unique distribution of the anion exchange protein in the sea lamprey, Petromyzon marinus. J Comp Physiol B 2000; 170:497-504. [PMID: 11128439 DOI: 10.1007/s003600000127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The purpose of the present study was to examine the distribution of the anion exchange protein in the sea lamprey. Southern blots showed that genomic DNA of juvenile lampreys possesses several regions that are similar to segments of the AE gene from other vertebrates. However, physiological experiments examining rapid anion fluxes across the red blood cell (rbc) membrane and molecular experiments examining mRNA transcript levels both indicated that the anion exchange protein is absent in sea lamprey rbcs. In contrast, lamprey kidney, skeletal muscle, liver and heart tissue all appeared to possess mRNA transcripts for an AE protein. Further evidence for the presence of an AE protein in kidney tissue was obtained from Western blots. In order to evaluate the impact of the apparent rbc anion exchange limitations, the bicarbonate permeability of lamprey rbcs was also evaluated using mass spectrometry. The bicarbonate permeability of the lamprey rbc membrane was an order of magnitude lower than that of trout rbcs. Taken together, these results indicate that the gene for the AE protein is indeed present in lampreys, but it is not expressed in the rbc. Moreover, the process of CO2 transport in lamprey probably does not involve bicarbonate transport across the rbc membrane.
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Yoshikawa K, Ogawa T, Baer R, Hemmi H, Honda K, Yamauchi A, Inamoto T, Ko K, Yazumi S, Motoda H, Kodama H, Noguchi S, Gazdar AF, Yamaoka Y, Takahashi R. Abnormal expression of BRCA1 and BRCA1-interactive DNA-repair proteins in breast carcinomas. Int J Cancer 2000; 88:28-36. [PMID: 10962436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Breast cancer is one of the most common malignancies among women. The molecular mechanisms involved in breast carcinogenesis, however, remain to be elucidated. Although somatic mutation of BRCA1 is rare, BRCA1 protein expression is reduced in about 30% of sporadic breast carcinomas (Yoshikawa et al., Clin. Cancer Res., 5:1249-1261, 1999), indicating its possible involvement even in sporadic breast carcinogenesis. Among the BRCA1-interactive proteins are hRAD51 (a human homologue of Escherichia coli rec A protein), BARD1 (BRCA1-associated RING domain 1) and p53, all of which are involved in DNA repair. We have analyzed the expression patterns of the hRAD51, BARD1 and p53 proteins in five breast cancer cell lines, including a BRCA1-deficient cell line, and in 179 breast cancer tissue samples from Japanese women, including 113 sporadic, 47 hereditary (i.e., BRCA1 status unknown), and 19 BRCA1-associated cases. Of the 179 breast carcinomas, fifty-four (30%) exhibited reduced hRAD51 expression, and sixty-two (35%) exhibited p53 overexpression. On the other hand, reduced expression level of BARD1, and of hMSH2 and hMLH1, which are components of DNA mismatch-repair pathway and are involved in colorectal carcinogenesis, was observed respectively in only 10 (6%), 8 (5%) and 3 (2%) cases. The overall frequency of sporadic breast carcinomas with abnormal expression of either BRCA1 or the BRCA1-interactive proteins was 67% (76/113). These results indicate that there may be an important role for the BRCA1-associated DNA-repair pathway, not only in BRCA1-associated breast carcinomas, but also in sporadic breast carcinomas.
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Shinohara H, Zhou J, Yoshikawa K, Yazumi S, Ko K, Yamaoka Y, Mizukami T, Yoshida T, Akinaga S, Tamaoki T, Motoda H, Benedict WF, Takahashi R. Retinoblastoma protein-initiated cellular growth arrest overcomes the ability of cotransfected wild-type p53 to induce apoptosis. Br J Cancer 2000; 83:1039-46. [PMID: 10993652 PMCID: PMC2363552 DOI: 10.1054/bjoc.2000.1411] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The retinoblastoma gene, RB, participates in the regulation of the G1/S-phase transition and in p53-mediated apoptosis. We have previously reported that stably transfected RB functions as a growth and tumour suppressor in HTB9 human bladder carcinoma cells, which carry a mutation of the p53 gene at codon 280 and lack RB expression. To elucidate the potential role of RB in the regulation of p53-mediated apoptosis, we transfected a wt p53 expression plasmid under the control of the human cytomegalovirus promoter into parental and RB-transfected HTB9 cells. The p53(+)/RB(-)cells were susceptible to apoptosis under various experimental conditions: 1) incubation in serum-free culture for 72 h, 2) short-term (6 h) or long-term (48 h) exposure to etoposide, and 3) culturing in soft agar. In contrast, p53(+)/RB(+)cells were significantly resistant to apoptosis under similar conditions and exhibited efficient growth arrest, as measured by laser scanning cytometry. Tumorigenicity in nude mice of parental HTB9 cells was lost by exogenous expression of wt p53. Likewise, none of mice injected subcutaneously with either p53(-)/RB(+)or p53(+)/RB(+)cells developed tumours, indicating that RB allows suppression of tumorigenesis, regardless of p53 status. These results suggest that the growth-inhibitory function of RB may overcome the ability of wt p53 to induce apoptosis.
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Abstract
To correct crooked nail deformity, which results from the partial loss of the distal phalanx, soft-tissue restoration alone is usually not enough to restore the length and shape of the nail structure. The authors treated 10 crooked nail fingertips by modified osteoplastic reconstruction, which included the elevation of the dorsally based volar skin flap and an iliac bone graft covered by an adequate skin flap. During the postoperative follow-up, the nail straightened, although not to the preinjury extent, along the restored distal phalanx with bony support. The authors' osteoplastic reconstruction, which involves the enhancement of the fingertips with composite tissues, presents a practical method for the correction of crooked nail deformity.
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Ko K, Yazumi S, Yoshikawa K, Konda Y, Nakajima M, Chiba T, Takahashi R. Activation of fibroblast-derived matrix metalloproteinase-2 by colon-cancer cells in non-contact Co-cultures. Int J Cancer 2000; 87:165-71. [PMID: 10861469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Stromal fibroblasts interact with invading cancer cells by secreting and activating matrix metalloproteinases (MMPs). To elucidate the mechanisms involved in the expression and activation patterns of MMPs, human colon-cancer cell lines Caco-2 and LoVo and colon-fibroblast cell line CCD18-Co were co-cultivated in non-contact and contact conditions which mimic in vivo interaction between cancer cells and fibroblasts before and after cancer invasion respectively. Gelatin zymography disclosed that MMP-2 was secreted from the fibroblasts but not from the cancer cells. The quantity of fibroblast-derived MMP-2 in conditioned medium was not significantly changed in either the contact or the non-contact co-cultures when compared with that of individual cultures of CCD18-Co fibroblasts. Cancer cells in non-contact co-cultures, however, enhanced the activation of fibroblast-derived MMP-2. Transcripts of membrane-type matrix metalloproteinase-1 (MT1-MMP), which is thought to be present on the cell surface and to work as a candidate activator of MMP-2, were detected in both cancer cell lines. Plasma membrane extracts of cancer cells also activated MMP-2 in conditioned media in cell-free conditions. This activation of MMP-2 may be caused by MT1-MMP of the cancer cells, since it was inhibited by a series of MMP inhibitors, including ethylenediaminetetraacetic acid (EDTA), the tissue inhibitor of metalloproteinase-2 (TIMP-2), and the MMP inhibitor CGS 27023A, but not by TIMP-1. Our data demonstrate that in non-contact co-cultures colon-cancer cells activate fibroblast-derived MMP-2 on their plasma membranes. These findings should help to elucidate the mechanism involved in the initial destruction of basement membrane by cancer cells.
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Yazumi S, Ko K, Watanabe N, Shinohara H, Yoshikawa K, Chiba T, Takahashi R. Disrupted transforming growth factor-beta signaling and deregulated growth in human biliary tract cancer cells. Int J Cancer 2000. [PMID: 10842191 DOI: 10.1002/(sici)1097-0215(20000615)86:6<782::aid-ijc5>3.0.co;2-o] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Biliary tract carcinoma is a common neoplasm in Japan, and its treatment is difficult because it tends to promote fibrosis and easily invades surrounding tissues. To better characterize the biological features of this carcinoma, we investigated abnormalities in the transforming growth factor-beta (TGF-beta) signaling pathway in five human biliary tract cancer cell lines: RBE, KMBC, SK-ChA-1, Mz-ChA-1, and Mz-ChA-2. We stably transfected into these cells the luciferase reporter plasmid carrying promoter of the plasminogen activator inhibitor-1 gene, the expression of which is stimulated by TGF-beta1. Treating the KMBC and Mz-ChA-1 cells with TGF-beta1 neither inhibited cell growth nor stimulated luciferase activity. In contrast, the RBE and Mz-ChA-2 cells responded well to TGF-beta1 treatment. TGF-beta1-treated SK-ChA-1 cells exhibited attenuated luciferase activity and their growth was not inhibited. Smad4 mRNA was not detected in SK-ChA-1 and Mz-ChA-1 cells by Northern blot analysis. Genetic analysis disclosed a nonsense mutation in the Mad homologue 2a domain of the Smad4 gene in the SK-ChA-1 cells and a heterozygous deletion in the TGF-beta type II receptor gene in the KMBC cells. Expression of the exogenous Smad4 gene in the Mz-ChA-1 cells by transient transfection restored their luciferase activity. When these TGF-beta1-insensitive and less-TGF-beta1-sensitive cell lines were xenografted into nude mice, they developed tumors that had more prominent, intervening fibrosis (desmoplasia) than the tumors caused by TGF-beta1-sensitive cells. Thus, a tight correlation between disruption of the TGF-beta signaling pathway and deregulated growth of cancer cells has been demonstrated in biliary tract carcinoma. This seems to be a critical event in this carcinoma and may also be correlated with stromal cell reaction in cancer invasion.
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Ko K, Arora P, Lee W, McCulloch C. Biochemical and functional characterization of intercellular adhesion and gap junctions in fibroblasts. Am J Physiol Cell Physiol 2000; 279:C147-57. [PMID: 10898726 DOI: 10.1152/ajpcell.2000.279.1.c147] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Despite their significance in wound healing, little is known about the molecular determinants of cell-to-cell adhesion and gap junctional communication in fibroblasts. We characterized intercellular adherens junctions and gap junctions in human gingival fibroblasts (HGFs) using a novel model. Calcein-labeled donor cells in suspension were added onto an established, Texas red dextran (10 kDa)-labeled acceptor cell monolayer. Cell-to-cell adhesion required Ca(2+) and was >30-fold stronger than cell-to-fibronectin adhesion at 15 min. Electron micrographs showed rapid formation of adherens junction-like structures at approximately 15 min that matured by approximately 2-3 h; distinct gap junctional complexes were evident by approximately 3 h. Immunoblotting showed that HGF expressed beta-catenin and that cadherins and connexin43 were recruited to the Triton-insoluble cytoskeletal fraction in confluent cultures. Confocal microscopy localized the same molecules to intercellular contacts of acceptor and donor cells. There was extensive calcein dye transfer in a cohort of Texas red dextran-labeled cells, but this was almost completely abolished by the gap junction inhibitor beta-glycyrrhetinic acid and the connexin43 mimetic peptide GAP 27. This donor-acceptor cell model allows large numbers (>10(5)) of cells to form synchronous cell-to-cell contacts, thereby enabling the simultaneous functional and molecular studies of adherens junctions and gap junctions.
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Yazumi S, Ko K, Watanabe N, Shinohara H, Yoshikawa K, Chiba T, Takahashi R. Disrupted transforming growth factor-beta signaling and deregulated growth in human biliary tract cancer cells. Int J Cancer 2000; 86:782-9. [PMID: 10842191 DOI: 10.1002/(sici)1097-0215(20000615)86:6<782::aid-ijc5>3.0.co;2-o] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Biliary tract carcinoma is a common neoplasm in Japan, and its treatment is difficult because it tends to promote fibrosis and easily invades surrounding tissues. To better characterize the biological features of this carcinoma, we investigated abnormalities in the transforming growth factor-beta (TGF-beta) signaling pathway in five human biliary tract cancer cell lines: RBE, KMBC, SK-ChA-1, Mz-ChA-1, and Mz-ChA-2. We stably transfected into these cells the luciferase reporter plasmid carrying promoter of the plasminogen activator inhibitor-1 gene, the expression of which is stimulated by TGF-beta1. Treating the KMBC and Mz-ChA-1 cells with TGF-beta1 neither inhibited cell growth nor stimulated luciferase activity. In contrast, the RBE and Mz-ChA-2 cells responded well to TGF-beta1 treatment. TGF-beta1-treated SK-ChA-1 cells exhibited attenuated luciferase activity and their growth was not inhibited. Smad4 mRNA was not detected in SK-ChA-1 and Mz-ChA-1 cells by Northern blot analysis. Genetic analysis disclosed a nonsense mutation in the Mad homologue 2a domain of the Smad4 gene in the SK-ChA-1 cells and a heterozygous deletion in the TGF-beta type II receptor gene in the KMBC cells. Expression of the exogenous Smad4 gene in the Mz-ChA-1 cells by transient transfection restored their luciferase activity. When these TGF-beta1-insensitive and less-TGF-beta1-sensitive cell lines were xenografted into nude mice, they developed tumors that had more prominent, intervening fibrosis (desmoplasia) than the tumors caused by TGF-beta1-sensitive cells. Thus, a tight correlation between disruption of the TGF-beta signaling pathway and deregulated growth of cancer cells has been demonstrated in biliary tract carcinoma. This seems to be a critical event in this carcinoma and may also be correlated with stromal cell reaction in cancer invasion.
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Fujii K, Fujioka S, Kato K, Machiki Y, Kutsuna Y, Ishikawa A, Takamizawa J, Mizutani T, Ko K, Yoshida K. Factors influencing survival in 33 patients undergoing resection of hepatic metastases from colorectal cancer. HEPATO-GASTROENTEROLOGY 2000; 47:607-11. [PMID: 10918996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
BACKGROUND/AIMS To determine the factors influencing the prognosis of patients undergoing resection of hepatic metastases from colorectal cancer. METHODOLOGY Between December 1981 and March 1998, 33 patients underwent potentially curative hepatic resection for metastatic colorectal cancer at the Kiryu Kousei General Hospital. We retrospectively examined 15 factors, including 3 clinical factors, 5 primary tumor characteristics and 7 metastatic tumor characteristics. Survival rates were estimated by the Kaplan-Meier method, and the weighting of each factor was compared by the log-rank test. We used univariate and multivariate analyses to assess any associations between the factors and mortality. RESULTS The 30-day operative mortality was 0%. The 5-yr survival rate of the 33 patients was 43%. A significant survival advantage was noted in patients with 1 or 2 metastatic lesions (25/33, 76%), patients who underwent systematic anatomical resection (14/33, 42%) and male patients (16/33, 48%), compared with patients with 3 or more lesions (50% and 17%, P = 0.021), patients who underwent non-systematic resection (67% and 23%, P = 0.005) and female patients (65% and 20%, P = 0.011), respectively. No statistical influence on survival was found in the multivariate analysis of these 3 factors. Recurrence was identified in 24 patients (73%) and 19 of them died of recurrent cancer. CONCLUSIONS Surgical resection of hepatic metastases from colorectal cancer is safe and potentially curative in appropriately selected patients.
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Ko K, Habu Y, Kiyota K, Watanabe Y, Inokuchi H. [Symptoms of gastrointestinal reflux disease (including atypical symptoms)]. NIHON NAIKA GAKKAI ZASSHI. THE JOURNAL OF THE JAPANESE SOCIETY OF INTERNAL MEDICINE 2000; 89:21-7. [PMID: 10723913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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Ko K, Ko ZW. In vitro targeting of the Toc36 component of the chloroplast envelope protein import apparatus involves a complex set of information. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1421:198-206. [PMID: 10561484 DOI: 10.1016/s0005-2736(99)00126-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Toc36 is a family of 44-kDa envelope polypeptides previously identified as components of the chloroplast protein import apparatus. Toc36 exists as multiple outer and inner envelope membrane forms. One member, Toc36B (formerly Bce44B), is targeted to the envelope without the typical maturation event. Targeting and assembly into the envelope is thus likely to involve a complex interplay of indigenous signals. These signals were examined by testing the effects of truncations and chimeric fusions on the targeting of Toc36B. The targeting ability of Toc36B appeared unaffected by carboxyl truncations of up to 80% of the protein, but was abolished by N-terminal deletions. The N-terminal 39 residues of Toc36B conferred the same targeting profile to mouse dihydrofolate reductase as that displayed by unaltered Toc36B. However, removal of 18 residues from the carboxyl end of the N-terminal 39-amino acid segment abolished targeting to the chloroplast. Additional information in the remaining Toc36B segment was also apparent based on the import results of chimeric fusions between the transit peptide of the small subunit of ribulose-1,5-bisphosphate carboxylase and Toc36B. The targeting of Toc36B to various destinations in the chloroplast envelope appears to be influenced by information from at least two segments of the protein.
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Gruen MB, Ko K, Nosko MG. Civil war head injury and twentieth-century treatment. THE JOURNAL OF TRAUMA 1999; 47:151-3. [PMID: 10421202 DOI: 10.1097/00005373-199907000-00030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Ko K, Brown S, Düring K, Norelli J, Borejsza-Wysocka E, Aldwinckle H. EFFECT OF MULTIPLE TRANSGENES ON RESISTANCE TO FIRE BLIGHT OF 'GALAXY' APPLE. ACTA ACUST UNITED AC 1999. [DOI: 10.17660/actahortic.1999.489.43] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Norelli J, Borejsza-Wysocka E, Momol M, Mills J, Grethel A, Aldwinckle H, Ko K, Brown S, Bauer D, Beer S, Abdul-Kader A, Hanke V. GENETIC TRANSFORMATION FOR FIRE BLIGHT RESISTANCE IN APPLE. ACTA ACUST UNITED AC 1999. [DOI: 10.17660/actahortic.1999.489.50] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Borejsza-Wysocka E, Norelli J, Aldwinckle H, Ko K. TRANSFORMATION OF AUTHENTIC M.26 APPLE ROOTSTOCK FOR ENHANCED RESISTANCE TO FIRE BLIGHT. ACTA ACUST UNITED AC 1999. [DOI: 10.17660/actahortic.1999.489.44] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Diez-Roux G, Argilla M, Makarenkova H, Ko K, Lang RA. Macrophages kill capillary cells in G1 phase of the cell cycle during programmed vascular regression. Development 1999; 126:2141-7. [PMID: 10207139 DOI: 10.1242/dev.126.10.2141] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Programmed capillary regression occurs during normal development of the eye and serves as a useful model for assessing the forces that drive vascular involution. Using a combination of S-phase labeling and liposome-mediated macrophage elimination, we show that during regression, macrophages induce apoptosis of both pericytes and endothelial cells in a cell cycle stage-dependent manner. Target cells are signaled to die by macrophages approximately 15 hours after S-phase labeling and this corresponds to a point in mid-G1 phase of the cell cycle. The tight correlation between the restriction point of the cell cycle and the point where the macrophage death signal is received suggests that the mitogen, matrix and cytoskeletal signals essential for cell-cycle progression may be inhibited by macrophages as a means of inducing cell death. Furthermore, these experiments show that cells from two distinct lineages are induced to die as a consequence of macrophage action, and this provides evidence that macrophage-induced cell death may be a general phenomenon during development and homeostasis.
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Meeson AP, Argilla M, Ko K, Witte L, Lang RA. VEGF deprivation-induced apoptosis is a component of programmed capillary regression. Development 1999; 126:1407-15. [PMID: 10068634 DOI: 10.1242/dev.126.7.1407] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The pupillary membrane (PM) is a transient ocular capillary network, which can serve as a model system in which to study the mechanism of capillary regression. Previous work has shown that there is a tight correlation between the cessation of blood flow in a capillary segment and the appearance of apoptotic capillary cells throughout the segment. This pattern of cell death is referred to as synchronous apoptosis (Lang, R. A., Lustig, M., Francois, F., Sellinger, M. and Plesken, H. (1994) Development 120, 3395–3404; Meeson, A., Palmer, M., Calfon, M. and Lang, R. A. (1996) Development 122, 3929–3938). In the present study, we have investigated whether the cause of synchronous apoptosis might be a segmental deficiency of either oxygen or a survival factor. Labeling with the compound EF5 in a normal PM indicated no segmental hypoxia; this argued that oxygen deprivation was unlikely to be the cause of synchronous apoptosis. When rat plasma was used as a source of survival factors in an in vitro PM explant assay, inhibition of vascular endothelial growth factor (VEGF) all but eliminated the activity of plasma in suppressing apoptosis. This argued that VEGF was an important plasma survival factor. Furthermore, inhibition of VEGF in vivo using fusion proteins of the human Flk-1/KDR receptor resulted in a significantly increased number of capillaries showing synchronous apoptosis. This provides evidence that VEGF is necessary for endothelial cell survival in this system and in addition, that VEGF deprivation mediated by flow cessation is a component of synchronous apoptosis.
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Habu Y, Kiyota K, Inokuchi H, Sugano Y, Ko K, Waki S. [Evaluation of the efficacy and the cost-effectiveness of proton pump inhibitor-based dual and triple therapy regimens for H. pylori eradication in peptic ulcer disease]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 1999; 57:135-9. [PMID: 10036950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
To evaluate the efficacy and the cost-effectiveness of H. pylori eradication for the treatment of peptic ulcer disease, a randomized controlled trial to compare the efficacy of proton pump inhibitor-based dual and triple regimens was conducted. A decision analysis was also performed to assess H. pylori eradication compared to the conventional maintenance strategy. Two hundred and thirty-four peptic ulcer patients suffering from H. pylori infection were randomly treated with either omeprazole 20 mg bid + amoxicillin 500 mg qid + clarithromycin 400 mg bid (OAC) or with omeprazole 20 mg bid + clarithromycin 400 mg bid (OC) for 14 days. The eradication rate with OAC was 87.6% (92/105) (95% Confidence Interval (CI): 81-94%), which was significantly higher than that with OC (61.9% (60/97) (95% CI: 52-72%)) (p < 0.001, chi 2 test). Both regimens were safe and well tolerated. H. pylori eradication was more effective and less costly than conventional strategy in a long term perspective. OAC was more cost-effective than OC. In conclusion, H. pylori eradication is a cost-effective alternative to conventional treatment. We recommend 2 weeks triple regimen with omeprazole 20 mg bid + amoxicillin 500 mg qid + clarithromycin 400 mg bid (OAC) as a first-line treatment in all patients with peptic ulcers associated with H. pylori infection.
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Ogden AT, Nunes I, Ko K, Wu S, Hines CS, Wang AF, Hegde RS, Lang RA. GRIFIN, a novel lens-specific protein related to the galectin family. J Biol Chem 1998; 273:28889-96. [PMID: 9786891 DOI: 10.1074/jbc.273.44.28889] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The vertebrate lens is a relatively simple cellular structure that has evolved to refract light. The ability of the lens to focus light on the retina derives from a number of properties including the expression at high levels of a selection of soluble proteins referred to as the crystallins. In the present study, we have used differential cDNA display techniques to identify a novel, highly abundant and soluble lens protein. Though related to the family of soluble lectins called galectins, it does not bind beta-galactoside sugars and has atypical sequences at normally conserved regions of the carbohydrate-binding domain. Like some galectin family members, it can form a stable dimer. It is expressed only in the lens and is located at the interface between lens fiber cells despite the apparent lack of any membrane-targeting motifs. This protein is designated GRIFIN (galectin-related inter-fiber protein) to reflect its exclusion from the galectin family given the lack of affinity for beta-galactosides. Although the abundance, solubility, and lens-specific expression of GRIFIN would argue that it represents a new crystallin, its location at the fiber cell interface might suggest that its primary function is executed at the membrane.
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Abstract
Computerized tomography scanning-derived narrow band reflection holograms of patients undergoing craniofacial procedures were created to evaluate the applicability of superimposing these three-dimensional images (3-D) on the operative field during neurological surgery. These sterilized radiological holograms were positioned over the surgical site by using bone sutures as registration points between the skull and the 3-D image to serve as a visual template between the patient and surgeon. Surgeries were then performed with the surgeon looking through the radiological hologram at the patient. Holograms were accurate to within 2 mm (plus or minus) of the actual calvarial anatomy. The use of the holographic image as a visual guide during surgery eliminated intraoperative guesswork or free-handed contouring. To the author's knowledge, this is the first report of the superimposed holographic image used in situ during surgery.
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Pang P, Meathrel K, Ko K. A component of the chloroplast protein import apparatus functions in bacteria. J Biol Chem 1997; 272:25623-7. [PMID: 9325283 DOI: 10.1074/jbc.272.41.25623] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Toc36 is a family of 44-kDa envelope polypeptides previously identified as components of the chloroplast protein import apparatus by virtue of their close physical proximity to translocating proteins. An indication of their function thus remains at large. A heterologous in vivo approach for studying the function of Toc36 was developed in this study by introducing a member of Toc36 into E. coli to assess its effect on bacterial protein translocation. The presence of Toc36 enhances the translocation of two bacterial periplasmic proteins in a manner resembling the chloroplast system. Translocation of the two bacterial periplasmic proteins was less sensitive to sodium azide, resembling more the azide-insensitive nature of the chloroplast protein import process. Mutated Toc36 proteins were not capable of causing the same effect as that observed for unaltered Toc36. Toc36 was also capable of complementing bacterial strains with temperature-sensitive secA mutations that affected protein translocation. The combined results provide evidence that Toc36 plays a central role in the chloroplast protein translocation process.
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Schnell DJ, Blobel G, Keegstra K, Kessler F, Ko K, Soll J. A consensus nomenclature for the protein-import components of the chloroplast envelope. Trends Cell Biol 1997; 7:303-4. [PMID: 17708964 DOI: 10.1016/s0962-8924(97)01111-2] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Matsukawa Y, Tomita Y, Nishinarita S, Horie T, Kato K, Arakawa Y, Ko K, Shimada H, Nakano M, Kitami Y, Kurosaka H. Efficacy of lansoprazole against peptic ulcers induced by non-steroidal anti-inflammatory drugs: endoscopic evaluation of ulcer healing. J Int Med Res 1997; 25:190-5. [PMID: 9283991 DOI: 10.1177/030006059702500403] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Beyond the obvious step of limiting use of non-steroidal anti-inflammatory drugs (NSAIDs), the treatment of ulcers induced by NSAIDs remains controversial. We evaluated the efficacy of the proton-pump inhibitor lansoprazole on NSAID-induced ulcers. Ulcers were endoscopically diagnosed in 47 NSAID users. These patients received 30 mg/day lansoprazole, orally, for 6 or 8 weeks (6 weeks for duodenal ulcers and 8 weeks for other ulcers). Ulcer healing was assessed using an established classification system. The presence of immunoglobulin G antibody against Helicobacter pylori was also evaluated. The antibody was present in the sera of 51% of patients (24/47). Most of the ulcers reached scarring stages S1 (healing) or S2 (good healing), and the S2 healing rate was 35%. Two H. pylori seropositive patients did not reach these stages; their ulcers were improved by H. pylori eradication therapy, followed, in one case, by medication with misoprostol. Lansoprazole seemed to be useful for most patients with NSAID-induced ulcers, but a few needed additional treatments.
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