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Ho J, Joshi V, Elam K, Chin. TK, Talati A. 43 ASSESSMENT OF MYOCARDIAL ABNORMALITY IN PATIENTS WITH VENTRICULAR NONCOMPACTION USING THREE-DIMENSIONAL ECHOCARDIOGRAPHY. J Investig Med 2006. [DOI: 10.2310/6650.2005.x0008.42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Choi BC, Ho J, Arnup G, Freeman MR. Nonequilibrium domain pattern formation in mesoscopic magnetic thin film elements assisted by thermally excited spin fluctuations. PHYSICAL REVIEW LETTERS 2005; 95:237211. [PMID: 16384343 DOI: 10.1103/physrevlett.95.237211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2005] [Indexed: 05/05/2023]
Abstract
The dynamic behavior in the evolving pattern of thermally assisted, nonequilibrium domains in magnetic thin-film elements undergoing ultrafast 180 degrees magnetization reversal was studied. Magnetization reversal enters a fully dynamic regime when the external field conditions are changed much faster than the sample is able to respond. The dynamic pathway develops a complexity not seen in quasistatic reversal but still retains a high level of order with well-developed dynamic domain patterns formed in response to subnanosecond transitions of the external applied magnetic field.
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Ho J. DKA and thrombosis. CMAJ 2005. [DOI: 10.1503/cmaj.1050105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Ho J, Mak J, Ho S, Ip M, Tsang K, Lam W, Chan-Yeung M. P-290 Manganese superoxide dismutase and catalase geneticpolymorphisms, activity levels and lung cancer risk in Chinese in Hong Kong. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)80784-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
Most solid pancreatic tumors are exocrine adenocarcinomas. We presented a patient with primary ALCL of the pancreas masquerading as a carcinoma of the head of pancreas. She was scheduled for a Whipple's operation and the intra-operative frozen section showed anaplastic carcinoma. The proper diagnosis was only derived later with CD30 immunohistochemical study. This carries important implications on the management, as radical surgery is indicated in resectable carcinoma but not for a chemosensitive lymphoma.
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Forbes A, Al-Damluji A, Ashworth S, Bramble M, Herbert K, Ho J, Kang JY, Przemioslo R, Shetty A. Multicentre randomized-controlled clinical trial of Ipocol, a new enteric-coated form of mesalazine, in comparison with Asacol in the treatment of ulcerative colitis. Aliment Pharmacol Ther 2005; 21:1099-104. [PMID: 15854171 DOI: 10.1111/j.1365-2036.2005.02442.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND 5-Aminosalicylates remain important in the treatment of ulcerative colitis, but it is uncertain if the various preparations currently available are equivalent given the different delivery systems that exist. Generic prescription of mesalazine (mesalamine) is therefore inappropriate. Ipocol has recently become available as an alternative to Asacol-MR. AIM To compare the two agents in a controlled trial using a non-inferiority design. METHODS Eighty-eight ulcerative colitis patients with a mild to moderate clinical relapse were randomized to one of the two drugs at a daily dose of 2.4 g for 8 weeks. Safety was the key concern; the primary measured end-point was efficacy as judged from a colitis activity index. RESULTS There were no unexpected adverse events of clinical consequence. The colitis score improved similarly in both patient groups (by 2.3 with Ipocol and by 1.5 with Asacol: not significant), and a similar proportion was in clinical remission at the end of the study (26.1% for Ipocol and 28.6% for Asacol: not significant). Systemic steroids were needed in 11.9% of the Asacol-treated patients compared with 6.5% with Ipocol (not significant). CONCLUSION It appears appropriate to conclude that, while not identical to Asacol-MR, Ipocol offers a safe and similarly effective alternative.
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Ho J, Jevon G, Sanatani S. 102 ANOMALOUS ORIGIN OF THE LEFT CORONARY ARTERY WITH DIFFUSE CORONARY HYPOPLASIA RESULTING IN SUDDEN DEATH. J Investig Med 2005. [DOI: 10.2310/6650.2005.00005.101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Ho J, Lai YH, Benton D, Duffy D, Harrison R, Macnab AJ. 504 EVALUATION OF AN ORAL HEALTH PROMOTION PROGRAM IN A REMOTE FIRST NATIONS COMMUNITY. J Investig Med 2005. [DOI: 10.2310/6650.2005.00005.503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Laflamme C, Lavigne S, Ho J, Duchaine C. Assessment of bacterial endospore viability with fluorescent dyes. J Appl Microbiol 2004; 96:684-92. [PMID: 15012806 DOI: 10.1111/j.1365-2672.2004.02184.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM To validate three fluorescence viability assays designed primarily for vegetative cells on pure Bacillus endospores. METHODS AND RESULTS Purified fresh and gamma-irradiated Bacillus endospores (Bacillus cereus, B. coagulans and two strains of B. subtilis) were used. The viability assays were: 5-cyano-2,3-diotolyl tetrazolium chloride (CTC) to test respiratory activity and early germination, DiBAC4(3) and Live/Dead BacLight to measure membrane energization and permeabilization, respectively. Gamma irradiation treatment completely eliminated spore culturability and was used as negative control. The untreated spores showed respiratory activity after 1 h of incubation and this was characteristic of almost 100% of spores after 24 h. The membrane potential assessment gave no answer about spore viability. A lower proportion of untreated spores had permeabilized membrane compared with gamma-irradiated spores using Live/Dead BacLight (P < 0.02). CONCLUSION It is possible to use CTC and Live/Dead BacLight to rapidly test endospore viability and evaluate the proportion of spores in a preparation that could not be recovered with plate count. SIGNIFICANCE AND IMPACT OF THE STUDY This study shows that fluorescence tests could be applied to assess viability in potentially pathogenic Bacillus spore preparations within 1 h.
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Halperin TJ, Meier JL, Swislocki AL, Noth RH, Lopez JR, Ho J, Siegel D. 255 TRENDS IN DIABETIC MEDICATION UTILIZATION IN A VETERANS AFFAIRS REGION: THE IMPACT OF THIAZOLIDINEDIONE USE ON GLYCEMIC CONTROL. J Investig Med 2004. [DOI: 10.1136/jim-52-suppl1-255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Akanle OA, Ho J, Muhiddin K, Admans L, Croft NM, Spyrou NM. Elemental composition of hair and bone density measurements at diagnosis in paediatric inflammatory bowel disease. J Radioanal Nucl Chem 2004. [DOI: 10.1023/b:jrnc.0000017318.63963.fe] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Wong BCY, Wong WM, Cheung KL, Tong TSM, Rozen P, Young GP, Chu KW, Ho J, Law WL, Tung HM, Lai KC, Hu WHC, Chan CK, Lam SK. A sensitive guaiac faecal occult blood test is less useful than an immunochemical test for colorectal cancer screening in a Chinese population. Aliment Pharmacol Ther 2003; 18:941-6. [PMID: 14616158 DOI: 10.1046/j.1365-2036.2003.01783.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND Colorectal cancer screening by guaiac faecal occult blood test has been shown to reduce the incidence and mortality of colorectal cancer in Western populations. The optimal faecal occult blood test, whether guaiac or immunochemical, for colorectal cancer screening in the Chinese population remains to be defined. AIM To compare the performance characteristics of a sensitive guaiac-based faecal occult blood test (Hemoccult SENSA) and an immunochemical faecal occult blood test (FlexSure OBT) in a Chinese population referred for colonoscopy. METHODS One hundred and thirty-five consecutive patients who were referred for colonoscopy and who met the study inclusion criteria took samples for the two faecal occult blood tests simultaneously from three successive stool specimens, with no dietary restrictions. All tests were developed and interpreted by a single experienced technician who was blind to the clinical diagnosis. The sensitivity, specificity and positive predictive value for the detection of colorectal adenomas and cancers were estimated for the two tests. RESULTS The sensitivity, specificity and positive predictive value for the detection of significant colorectal neoplasia (adenomas > or = 1.0 cm and cancers) were 91%, 70% and 18% for Hemoccult SENSA and 82%, 94% and 47% for FlexSure OBT. The specificity and positive predictive value were significantly higher for FlexSure OBT than for Hemoccult SENSA (P < 0.001 and P = 0.016, respectively). Combining the positive results from both faecal occult blood tests did not improve the accuracy. CONCLUSION The positive predictive value of the immunochemical faecal occult blood test for the detection of significant colorectal neoplasia was 29% better than that of the sensitive guaiac-based test. This may relate to the Chinese diet and requires further study. The poor specificity of the sensitive guaiac-based test, without dietary restriction, makes it less useful for colorectal cancer screening in a Chinese population.
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Ho J, Benchimol S. Transcriptional repression mediated by the p53 tumour suppressor. Cell Death Differ 2003; 10:404-8. [PMID: 12719716 DOI: 10.1038/sj.cdd.4401191] [Citation(s) in RCA: 162] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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Streutker CJ, Huizinga JD, Campbell F, Ho J, Riddell RH. Loss of CD117 (c-kit)- and CD34-positive ICC and associated CD34-positive fibroblasts defines a subpopulation of chronic intestinal pseudo-obstruction. Am J Surg Pathol 2003; 27:228-35. [PMID: 12548170 DOI: 10.1097/00000478-200302000-00012] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Chronic idiopathic intestinal pseudo-obstruction is a syndrome in which symptoms of intestinal obstruction are present in the absence of mechanical obstruction. Lack of normal pacemaker activity, usually generated by the interstitial cells of Cajal (ICC), could account for the apparent obstruction. ICC are normally located around and between the myenteric plexus ganglia and within muscle and also in the deep muscular plexus of the small bowel and the submuscular plexus of the large intestine, just within the circular muscle. ICC can be demonstrated immunohistochemically with CD117 (c-kit) as well as with CD34, although this is less specific. CD34 also stains a population of fibroblasts that are intimately associated with ICC. To determine whether there is a relative deficiency of ICC and CD34-positive fibroblasts in patients with chronic idiopathic intestinal pseudo-obstruction, tissue from 30 patients of large intestine and eight patients with small intestine pseudo-obstruction was obtained. Controls (large intestinal specimens from 12 patients, small intestinal specimens from six patients) were chosen from resections for Crohn's disease and colorectal neoplasia, both with and without dilatation. Examination of pseudo-obstruction cases identified 10 patients (nine large intestinal and one small intestinal) in which both CD117 and CD34 were absent or severely reduced in all three of the examined areas. In contrast, the control cases, including those with preobstructive dilatation, showed relatively constant ICC staining. These results suggest that there is a proportion of pseudo-obstruction cases in which the ICC are markedly reduced. These results also demonstrate that, in these cases, loss of the kit immunoreactivity is correlated with the loss of CD34 staining: this indicates that both the ICC and the CD34-positive fibroblasts associated with the ICC are absent. These findings will allow surgical pathologists to identify this subpopulation of patients with CIIP using tissue obtained by laparoscopic biopsy of the muscularis propria or surgical resection.
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Tamamori Y, Sawada T, Nishihara T, Yamashita Y, Ohira M, Ho J, Kim YS, Hirakawa-Ys Chung K. Granulocyte-colony stimulating factor enhances chimeric antibody Nd2 dependent cytotoxicity against pancreatic cancer mediated by polymorphonuclear neutrophils. Int J Oncol 2002. [DOI: 10.3892/ijo.21.3.649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Lau HKF, Ho J. Regulation of plasminogen activator inhibitor-1 secretion by growth factors in smooth muscle cells. Blood Coagul Fibrinolysis 2002; 13:541-9. [PMID: 12192306 DOI: 10.1097/00001721-200209000-00009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Epithelioid-type vascular smooth muscle cells are metabolically active and secrete many proteases and protease inhibitors. We have previously cloned epithelioid-type smooth muscle cells from rat carotid arteries, and showed that polypeptide growth factors basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) could dose-dependently induce plasminogen activator inhibitor-1 (PAI-1) secretion from these cells. In the present study, we have used these cells to investigate the growth factor-induced signal transduction pathways leading to PAI-1 secretion. We report here that PAI-1 induction was dependent on protein kinase C (PKC) and tyrosine kinase but not on protein kinase A (PKA), ras and phosphoinositol-3-kinase inhibitor. Induction of PAI-1 by bFGF and PDGF was also accompanied by activation of a mitogen-activated protein kinase pathway involving Raf/Mek/Erk1/2, and the family non-receptor tyrosine kinases., another non-receptor tyrosine kinase, on the contrary, behaved differently from in that it was part of a pathway leading to PAI-1 induction by bFGF, but not when PDGF was used as the stimulating reagent. Activation of a PKA-dependent pathway(s) opposed PAI-1 induction. One mechanism for PKA activators to inhibit PAI-1 secretion was that they markedly inhibited the phosphorylations of Mek and mitogen-activated protein kinase that were up-regulated in the presence of bFGF and PDGF.
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Ho J. Easy-to-use multilingual communication over the internet—facilitating “E-Business” for the Hotel Industry. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0010-8804(02)80028-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Chim CS, Shek TWH, Chung LP, Ho J. Gut perforation in MALT lymphoma of colon. Haematologica 2002; 87:EIM15. [PMID: 11940502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
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He X, Tabaczewski P, Ho J, Stroynowski I, Garcia KC. Promiscuous antigen presentation by the nonclassical MHC Ib Qa-2 is enabled by a shallow, hydrophobic groove and self-stabilized peptide conformation. Structure 2001; 9:1213-24. [PMID: 11738047 DOI: 10.1016/s0969-2126(01)00689-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Qa-2 is a nonclassical MHC Ib antigen, which has been implicated in both innate and adaptive immune responses, as well as embryonic development. Qa-2 has an unusual peptide binding specificity in that it requires two dominant C-terminal anchor residues and is capable of associating with a substantially more diverse array of peptide sequences than other nonclassical MHC. RESULTS We have determined the crystal structure, to 2.3 A, of the Q9 gene of murine Qa-2 complexed with a self-peptide derived from the L19 ribosomal protein, which is abundant in the pool of peptides eluted from the Q9 groove. The 9 amino acid peptide is bound high in a shallow, hydrophobic binding groove of Q9, which is missing a C pocket. The peptide makes few specific contacts and exhibits extremely poor shape complementarity to the MHC groove, which facilitates the presentation of a degenerate array of sequences. The L19 peptide is in a centrally bulged conformation that is stabilized by intramolecular interactions from the invariant P7 histidine anchor residue and by a hydrophobic core of preferred secondary anchor residues that have minimal interaction with the MHC. CONCLUSIONS Unexpectedly, the preferred secondary peptide residues that exhibit tenuous contact with Q9 contribute significantly to the overall stability of the peptide-MHC complex. The structure of this complex implies a "conformational" selection by Q9 for peptide residues that optimally stabilize the large bulge rather than making intimate contact with the MHC pockets.
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Abstract
OBJECTIVE Transanal and transvaginal repair of rectocele have been advocated in the treatment of rectocele, with mixed results. The aim of this study was to assess our experience using anterior levatorplasty in the surgical management of rectocele. PATIENTS AND METHODS Sixty of 90 women who had undergone anterior levatorplasty for rectocele over a seven year period were traced, and 44 (33 with rectocele only and 11 with rectocele and faecal incontinence) responded to a standardized questionnaire 6 months to 7 years (mean 3.5 years) after anterior levatorplasty. Results were expressed in general and specific improvement of symptoms and were classified as excellent, good, fair, or poor. The effects on social activities, sexual function, and employment were also assessed. RESULTS General satisfaction with the operation was rated as good or excellent in 27 of 33 (82%) and 18 of 24 (75%) patients with rectocele only at 2 and 3.2 years follow-up, respectively, and in 7 of 11 (64%) and 5 of 11 (45%) patients with rectocele and faecal incontinence at 2 and 4 years follow-up, respectively. 31 (70%) and 34 (77%) of all patients reported an improvement in sensation and the ability to defaecate, respectively. An improvement in social activities, sexual satisfaction and employment was noted in 10 of 21 (48%), 10 of 23 (43%), and 7 of 12 (58%) patients, respectively. CONCLUSION Anterior levatorplasty provides good short and long-term symptomatic improvement in patients with rectocele and avoids complications associated with rectal or vaginal approaches.
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Sze DM, Giesajtis G, Brown RD, Raitakari M, Gibson J, Ho J, Baxter AG, Fazekas de St Groth B, Basten A, Joshua DE. Clonal cytotoxic T cells are expanded in myeloma and reside in the CD8(+)CD57(+)CD28(-) compartment. Blood 2001; 98:2817-27. [PMID: 11675356 DOI: 10.1182/blood.v98.9.2817] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The occurrence of clonal T cells in multiple myeloma (MM), as defined by the presence of rearrangements in the T-cell receptor (TCR)-beta chains detected on Southern blotting, is associated with an improved prognosis. Recently, with the use of specific anti-TCR-variable-beta (anti-TCRV(beta)) antibodies, the presence in MM patients of expanded populations of T cells expressing particular V(beta) regions was reported. The majority of these T-cell expansions have the phenotype of cytotoxic T cells (CD8(+)CD57(+) and perforin positive). Since V(beta) expansions can result from either a true clonal population or a polyclonal response, the clonality of CD8(+)TCRV(beta)(+) T cells was tested by TCRV(beta) complementarity-determining region 3 length analysis and DNA sequencing of the variable region of the TCR. In this report, the CD57(+) and CD57(-) subpopulations within expanded TCRV(beta)(+)CD8(+) cell populations are compared, and it is demonstrated that the CD57(+) subpopulations are generally monoclonal or biclonal, whereas the corresponding CD57(-) cells are frequently polyclonal. The oligoclonality of CD57(+) expanded CD8(+) T cells but not their CD57(-) counterparts was also observed in age-matched controls, in which the T-cell expansions were mainly CD8(-). The CD8(+)CD57(+) clonal T cells had a low rate of turnover and expressed relatively lower levels of the apoptotic marker CD95 than their CD57(-) counterparts. Taken together, these findings demonstrate that MM is associated with CD57(+)CD8(+) T-cell clones, raising the possibility that the expansion and accumulation of activated clonal CD8(+) T cells in MM may be the result of persistent stimulation by tumor-associated antigens, combined with a reduced cellular death rate secondary to reduced expression of the apoptosis-related molecule CD95.
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Andreyev HJ, Norman AR, Cunningham D, Oates J, Dix BR, Iacopetta BJ, Young J, Walsh T, Ward R, Hawkins N, Beranek M, Jandik P, Benamouzig R, Jullian E, Laurent-Puig P, Olschwang S, Muller O, Hoffmann I, Rabes HM, Zietz C, Troungos C, Valavanis C, Yuen ST, Ho JW, Croke CT, O'Donoghue DP, Giaretti W, Rapallo A, Russo A, Bazan V, Tanaka M, Omura K, Azuma T, Ohkusa T, Fujimori T, Ono Y, Pauly M, Faber C, Glaesener R, de Goeij AF, Arends JW, Andersen SN, Lövig T, Breivik J, Gaudernack G, Clausen OP, De Angelis PD, Meling GI, Rognum TO, Smith R, Goh HS, Font A, Rosell R, Sun XF, Zhang H, Benhattar J, Losi L, Lee JQ, Wang ST, Clarke PA, Bell S, Quirke P, Bubb VJ, Piris J, Cruickshank NR, Morton D, Fox JC, Al-Mulla F, Lees N, Hall CN, Snary D, Wilkinson K, Dillon D, Costa J, Pricolo VE, Finkelstein SD, Thebo JS, Senagore AJ, Halter SA, Wadler S, Malik S, Krtolica K, Urosevic N. Kirsten ras mutations in patients with colorectal cancer: the 'RASCAL II' study. Br J Cancer 2001; 85:692-6. [PMID: 11531254 PMCID: PMC2364126 DOI: 10.1054/bjoc.2001.1964] [Citation(s) in RCA: 654] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Researchers worldwide with information about the Kirsten ras (Ki-ras) tumour genotype and outcome of patients with colorectal cancer were invited to provide that data in a schematized format for inclusion in a collaborative database called RASCAL (The Kirsten ras in-colorectal-cancer collaborative group). Our results from 2721 such patients have been presented previously and for the first time in any common cancer, showed conclusively that different gene mutations have different impacts on outcome, even when the mutations occur at the same site on the genome. To explore the effect of Ki-ras mutations at different stages of colorectal cancer, more patients were recruited to the database, which was reanalysed when information on 4268 patients from 42 centres in 21 countries had been entered. After predetermined exclusion criteria were applied, data on 3439 patients were entered into a multivariate analysis. This found that of the 12 possible mutations on codons 12 and 13 of Kirsten ras, only one mutation on codon 12, glycine to valine, found in 8.6% of all patients, had a statistically significant impact on failure-free survival (P = 0.004, HR 1.3) and overall survival (P = 0.008, HR 1.29). This mutation appeared to have a greater impact on outcome in Dukes' C cancers (failure-free survival, P = 0.008, HR 1.5; overall survival P = 0.02, HR 1.45) than in Dukes' B tumours (failure-free survival, P = 0.46, HR 1.12; overall survival P = 0.36, HR 1.15). Ki-ras mutations may occur early in the development of pre-cancerous adenomas in the colon and rectum. However, this collaborative study suggests that not only is the presence of a codon 12 glycine to valine mutation important for cancer progression but also that it may predispose to more aggressive biological behaviour in patients with advanced colorectal cancer.
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Chan TL, Curtis LC, Leung SY, Farrington SM, Ho JW, Chan AS, Lam PW, Tse CW, Dunlop MG, Wyllie AH, Yuen ST. Early-onset colorectal cancer with stable microsatellite DNA and near-diploid chromosomes. Oncogene 2001; 20:4871-6. [PMID: 11521198 DOI: 10.1038/sj.onc.1204653] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2001] [Revised: 02/27/2001] [Accepted: 05/23/2001] [Indexed: 12/25/2022]
Abstract
Colorectal cancer has been described in terms of genetic instability selectively affecting either microsatellite sequences (MIN) or chromosome number and structure (CIN). A subgroup with apparently stable, near-diploid chromosomes and stable microsatellites (MACS) also exists. These distinctions are important, partly because of their value in highlighting different pathways of carcinogenesis, and partly because of their direct relevance to prognosis. Study of early-onset cancer has often proved a fruitful resource for the identification of the nature and function of cancer susceptibility genes. In a study of colorectal cancer with stable microsatellite DNA, we describe 22 early-onset tumours (mean age=33), compared with 16 late-onset tumours (mean age=68). Both groups contained carcinomas with the MACS phenotype, characterized by near diploid DNA content, as defined by flow cytometry, and minimal chromosome arm deletion or amplification (six or less events per genome), determined by comparative genomic hybridization (CGH). Minimal chromosome imbalance correlated strongly with diploid DNA content (P<0.001). The proportion of MACS cancers was significantly greater in early-onset as compared to late-onset tumours (64 vs 13%, P=0.005). Of the chromosome arm imbalances commonly observed in late-onset tumours, only 18q- was observed more than twice amongst the 14 early-onset MACS tumours. Seventy-nine per cent of these MACS tumours were located in the distal colon, and 69% were at advanced clinico-pathological stages (with lymph node or distant metastasis). A positive family history of colorectal or other cancers was elicited in seven patients in the MACS early-onset group, and one additional patient in this group had a metachronous ovarian cancer. The results suggest that MACS cancer may have a genetic basis different from either MIN or CIN, and further studies of these cancers may lead to discovery of new mechanisms of colorectal carcinogenesis and cancer susceptibility.
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Ho J. Mortality and morbidity of the small for gestational age (SGA) very low birth weight (VLBW) Malaysian infant. Singapore Med J 2001; 42:355-9. [PMID: 11764052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To compare the neonatal course of small for gestational age (SGA) and appropriate for gestational age (AGA) preterm infants 1500 g or less birthweight. METHOD A total of 116 infants SGA infants 32 weeks or less were matched with 116 AGA infants of the same gestation, ethnic group, sex and where possible inborn or outborn status. RESULTS Significantly more SGA infants had a 1-minute Apgar scores of 3 or less, odds ratio (OR) 2.54 (95% Confidence Interval (CI) 1.25, 5.20) and a Critical Risk Index in Babies (CRIB) score > 5, OR 2.09 (95% CI 1.07, 4.09). They were significantly more likely to have hypotension, 35.5 versus 22.3%, OR 1.90 (95% CI 1.01, 3.59). There was no difference in the frequency of respiratory distress syndrome, mechanical ventilation, infection or rate of congenital malformation. Mortality before hospital discharge was significantly greater for the SGA infant (52.6 versus 28.4%, OR 2.79 (95% CI 1.56, 5.02)). This difference remained significant after exclusion of congenital abnormalities. Survivors had a longer mean duration of stay, (54.4 versus 41.2 days, p < 0.001). CONCLUSION The higher mortality seen in SGA infants appears to be due to a poorer condition at birth. There is no evidence that SGA infants have more mature lungs so antenatal corticosteroids should not be withheld on these grounds.
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Chow D, Ho J, Nguyen Pham TL, Rose-John S, Garcia KC. In vitro reconstitution of recognition and activation complexes between interleukin-6 and gp130. Biochemistry 2001; 40:7593-603. [PMID: 11412113 DOI: 10.1021/bi010192q] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Gp130 is a shared signal-transducing receptor for a family of four-helix cytokines, of which interleukin-6 is a prototypic member. IL-6-type cytokines activate gp130 to elicit downstream intracellular JAK/STAT signaling cascades through formation of hetero-oligomeric receptor complexes. Interleukin-6 must first complex with its specific alpha-receptor (Ralpha) in order to bind and activate gp130. We have dissected the extracellular activation pathway of human gp130 by human IL-6 through reconstitution of soluble complexes representing intermediate and final states in the hierarchical assembly of the IL-6/IL-6Ralpha/gp130 signaling complex. To isolate these hetero-complexes, we have applied a protein engineering strategy of covalently linking IL-6 to its Ralpha, which results in a "hyperactive" single-chain complex (hyper-IL-6) which we express in both Escherichia coli and insect cells. We have determined that IL-6/IL-Ralpha and the cytokine-binding homology region (CHR) of gp130 (D2D3) form a stable trimolecular "recognition" complex (trimer) consisting of 1IL-6,1 IL-6Ralpha, and 1 gp130-CHR. Addition of the N-terminal (D1) Ig-like domain (IGD) of gp130 to the CHR results in a transition to a hexameric "activation" complex containing 2 IL-6, 2IL-6Ralpha, and 2 gp130. These results clearly demonstrate that the recognition and activation complexes are disparate hetero-oligomeric molecular species linked by the recruitment of the gp130 IGD by the unique site III epitope present on all gp130-class cytokines. The results of these studies are relevant to other members of the IL-6 family of gp130-cytokines and address a longstanding question concerning the respective roles of the gp130 CHR and IGD in assembly of the active signaling oligomer.
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