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Willoughby S, van den Heuvel C, Chin A, Hodge G, Martin J, Nelson A, Worthley M, Kennedy D. Sleep Disordered Breathing in Children is Associated with Increased Platelet Aggregation, Systemic Inflammation and Endothelial Dysfunction. Heart Lung Circ 2011. [DOI: 10.1016/j.hlc.2011.05.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Chin A, Gelwick F, Laurencio D, Laurencio LR, Byars MS, Scoggins M. Linking Geomorphological and Ecological Responses in Restored Urban Pool-Riffle Streams. ECOL RESTOR 2010. [DOI: 10.3368/er.28.4.460] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Naiditch JA, Duerst R, Pillai S, Chin A. Nonoperative management of pneumatosis intestinalis and pneumoperitoneum in a patient with acute lymphoblastic leukemia: case report and review of the literature. Eur J Pediatr Surg 2010; 20:426-9. [PMID: 20623447 DOI: 10.1055/s-0030-1254148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Tantemsapya N, Chin A, Melin-Aldana H, Superina RA. Intrapancreatic duodenal duplication cyst as a cause of chronic pancreatitis in a child. Eur J Pediatr Surg 2010; 20:125-8. [PMID: 19530069 DOI: 10.1055/s-0029-1224192] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Nelson A, Cameron J, Carbone A, Chin A, Willoughby S, Puri R, van den Heuvel C, Martin J, Kennedy D, Worthley S, Worthley M. Teenage Years are Associated with Preferential Stiffening of the Proximal Aorta. Heart Lung Circ 2010. [DOI: 10.1016/j.hlc.2010.06.705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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van Hezewijk M, Creutzberg C, Putter H, Chin A, Willemze R, Marijnen C. 9325 Efficacy of a hypofractionated schedule in electron beam radiotherapy for epithelial skin cancer: analysis of 434 cases. EJC Suppl 2009. [DOI: 10.1016/s1359-6349(09)71969-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Jansen W, Chin A, De Vroome H, Noordijk E. VERIFICATION OF LUNG SHIELDING DURING TOTAL BODY IRRADIATION USING SELF-DEVELOPING RADIOCHROMIC FILM. Radiother Oncol 2009. [DOI: 10.1016/s0167-8140(12)73209-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Kabre R, Chin A, Rowell E, Browne M, Barsness KA, Luck S, Jona J. Hazardous complications of multiple ingested magnets: report of four cases. Eur J Pediatr Surg 2009; 19:187-9. [PMID: 19023855 DOI: 10.1055/s-2008-1038824] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Foreign body ingestion is a common occurrence in the pediatric population. Frequent culprits include coins, toys, sharp objects and bones, which most often pass spontaneously. Magnet ingestion, however, can be a serious matter, especially when more than one is taken in. The extremely strong magnetic force between multiple magnets may result in numerous complications including bowel necrosis, perforation, obstruction, fistula formation, volvulus and death. We present the largest series reported to date, with four cases of multiple magnet ingestion at our institution with varied presentations and findings. We review the literature, and discuss the importance of having a high index of suspicion.
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Evans CT, Hershow RC, Chin A, Foulis PR, Burns SP, Weaver FM. Bloodstream infections and setting of onset in persons with spinal cord injury and disorder. Spinal Cord 2009; 47:610-5. [PMID: 19238165 DOI: 10.1038/sc.2009.2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
STUDY DESIGN A retrospective cohort study. OBJECTIVE Health-care-associated (HCA) bloodstream infection (BSI) has been shown to be a distinct epidemiologic category in the general adult population, but few studies have examined specific patient populations. The objective of this study was to assess characteristics associated with BSI that occurred in the hospital (hospital-acquired, HA BSI), from health-care contact outside the hospital (HCA BSI) or in the community (community-acquired, CA BSI) in veterans with spinal cord injury and disorder (SCI&D). SETTING Two United States Department of Veterans Affairs hospitals. METHODS All patients with SCI&D with a positive blood culture admitted to study hospitals over a 7-year period (1 October 1997 to 30 September 2004). Demographics, medical characteristics and causative organisms were collected. RESULTS Four hundred and thirteen episodes of BSI occurred in 226 patients, with a rate of 7.2 BSI episodes per 100 admissions: 267 (64.7%) were HA BSI, 110 (26.6%) were HCA BSI and 36 (8.7%) were CA BSI. Antibiotic resistance was more common in those with HA BSI (65.5%) compared with that in those with HCA (49.1%, P=0.001) and CA BSI (22.2%, P<0.0001). Methicillin resistance in Staphylococcus aureus was highly prevalent; HA BSI (84.5%), HCA BSI (60.6%) and CA BSI (33.3%). CONCLUSION HCA BSI comprises one-quarter of all BSIs in hospitalized patients with SCI&D. Although those with HCA and CA BSI share similarities, several differences in medical characteristics and causal microorganism are noted. Treatment and management strategies for HCA and CA infections need to vary.
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Paczesny S, Levine J, Hogan J, Crawford J, Braun T, Wang H, Faca V, Zhang Q, Pitteri S, Chin A, Choi S, Kitko C, Krijanovski O, Reddy P, Mineishi S, Whitfield J, Jones D, Hanash S, Ferrara J. Elafin is a Biomarker of Graft Versus Host Disease of the Skin. Biol Blood Marrow Transplant 2009. [DOI: 10.1016/j.bbmt.2008.12.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Chin A, Garcia-Elias M. Combined reverse perilunate and axial-ulnar dislocation of the wrist: a case report. J Hand Surg Eur Vol 2008; 33:672-6. [PMID: 18606628 DOI: 10.1177/1753193408091348] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A 31 year-old professional motorcycle racer had an accident, resulting in an axial-ulnar dislocation of his right dominant wrist with derangement of the trapeziocapitate joint and dorsal dislocation of the capitate together with the triquetrum, the hamate and the corresponding metacarpals. Open reduction and wire fixation obtained excellent functional results at 1 year. This pattern of carpal derangement has not been previously described in the literature.
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Syed M, Syed S, Harrower S, Singh J, Chin A, McLellan D, Parkinson E, Clark L. Gamma tubulin: a powerful indicator of recurrence in human squamous cell carcinoma of the larynx. Clin Otolaryngol 2007. [DOI: 10.1111/j.1749-4486.2007.01568_9.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Tressler R, Kornbrust D, Chin A, Harley C, Behrs M, Elias L. 623 POSTER GRN163L, a telomerase inhibitor under development for cancer treatment: data guiding clinical trial design. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)70628-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Chang H, Noyes N, Lee T, Chin A, Krey L, Grifo J. P-232. Fertil Steril 2006. [DOI: 10.1016/j.fertnstert.2006.07.584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Rutkove S, Chin A, Shiffman C, Aaron R. P22.9 Measurement of muscle anisotropy using electrical impedance myography. Clin Neurophysiol 2006. [DOI: 10.1016/j.clinph.2006.06.426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Shammas MA, Koley H, Tassone P, Neri P, Protopopov A, Gryaznov S, Chin A, Anderson KC, Munshi NC. Novel and potent telomerase antagonist (GRN163L) inhibits telomerase activity, resulting in telomere shortening and apoptosis of multiple myeloma cells. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.6605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Chin A, Bérubé PR. Removal of disinfection by-product precursors with ozone-UV advanced oxidation process. WATER RESEARCH 2005; 39:2136-44. [PMID: 15882889 DOI: 10.1016/j.watres.2005.03.021] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Revised: 03/05/2005] [Indexed: 05/02/2023]
Abstract
The efficacy of using ozone (O3), ultraviolet irradiation (UV) and the combined O3-UV advanced oxidation process (AOP) to remove 2 classes of disinfection by-product (DBP) precursors from raw surface water samples have been evaluated and compared. In particular, trihalomethane and haloacetic acids formation potentials were measured. Laboratory batch scale experiments were carried out as a function of ozone and UV dosage in order to study the removal kinetics. It is concluded that the combined O3-UV AOP is more effective than either the ozone or UV treatment alone. Ozone-UV AOP is capable of mineralizing up to 50% of the total organic carbon from the raw source water at an ozone dose of 0.62+/-0.019 mg O3/mL and a UV dose of 1.61 W s/cm2. In addition, O3-UV AOP can reduce trihalomethane formation potential by roughly 80% and haloacetic acids formation potential by roughly 70% at the same ozone and UV dosage.
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Zhang D, Choi DW, Wanamaker S, Fenton RD, Chin A, Malatrasi M, Turuspekov Y, Walia H, Akhunov ED, Kianian P, Otto C, Simons K, Deal KR, Echenique V, Stamova B, Ross K, Butler GE, Strader L, Verhey SD, Johnson R, Altenbach S, Kothari K, Tanaka C, Shah MM, Laudencia-Chingcuanco D, Han P, Miller RE, Crossman CC, Chao S, Lazo GR, Klueva N, Gustafson JP, Kianian SF, Dubcovsky J, Walker-Simmons MK, Gill KS, Dvorák J, Anderson OD, Sorrells ME, McGuire PE, Qualset CO, Nguyen HT, Close TJ. Construction and evaluation of cDNA libraries for large-scale expressed sequence tag sequencing in wheat (Triticum aestivum L.). Genetics 2005; 168:595-608. [PMID: 15514038 PMCID: PMC1448820 DOI: 10.1534/genetics.104.034785] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A total of 37 original cDNA libraries and 9 derivative libraries enriched for rare sequences were produced from Chinese Spring wheat (Triticum aestivum L.), five other hexaploid wheat genotypes (Cheyenne, Brevor, TAM W101, BH1146, Butte 86), tetraploid durum wheat (T. turgidum L.), diploid wheat (T. monococcum L.), and two other diploid members of the grass tribe Triticeae (Aegilops speltoides Tausch and Secale cereale L.). The emphasis in the choice of plant materials for library construction was reproductive development subjected to environmental factors that ultimately affect grain quality and yield, but roots and other tissues were also included. Partial cDNA expressed sequence tags (ESTs) were examined by various measures to assess the quality of these libraries. All ESTs were processed to remove cloning system sequences and contaminants and then assembled using CAP3. Following these processing steps, this assembly yielded 101,107 sequences derived from 89,043 clones, which defined 16,740 contigs and 33,213 singletons, a total of 49,953 "unigenes." Analysis of the distribution of these unigenes among the libraries led to the conclusion that the enrichment methods were effective in reducing the most abundant unigenes and to the observation that the most diverse libraries were from tissues exposed to environmental stresses including heat, drought, salinity, or low temperature.
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Chin A, Glebe BD, Woo PTK. Humoral response and susceptibility of five full-sib families of Atlantic salmon, Salmo salar L., to the haemoflagellate, Cryptobia salmositica. JOURNAL OF FISH DISEASES 2004; 27:471-481. [PMID: 15291789 DOI: 10.1111/j.1365-2761.2004.00568.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Susceptibility and antibody production against pathogenic and vaccine strains of the haemoflagellate, Cryptobia salmositica were investigated in five full-sib families (A-E) of Atlantic salmon, Salmo salar. Humoral response and susceptibility of families were compared within three treatments: infection, vaccination and vaccination followed by challenge. Parasitaemias caused by the vaccine strain of C. salmositica were considerably lower than those caused by the pathogenic strain. All vaccinated families were protected when challenged with the pathogenic strain. Family B had significantly lower parasitaemias (with both strains) than the other families. When naïve fish were infected with the pathogenic strain, this family had a significantly lower and earlier peak parasitaemia (4.3 +/-1.3 x 10(6) parasites mL(-1) blood at 3 weeks post-infection; w.p.i.) than the other families. Family C had the highest peak (11.1 +/- 1.2 x 10(6) parasites mL(-1) blood), which occurred at 4 w.p.i. Antibodies against C. salmositica were detected earlier in Family B (3 w.p.i.) than in Family C (5 w.p.i.). This demonstrates an association of increased susceptibility with a delayed antibody response. Western immunoblot identified antibodies against 112, 181 and 200 kDa antigens earlier in more resistant fish (Family B). Antigenic stimulation leading to a stronger antibody response was shown with the vaccine strain and in the later stages of infection.
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Wondergem J, Wedekind LE, Bart CI, Chin A, van der Laarse A, Beekhuizen H. Irradiation of mechanically-injured human arterial endothelial cells leads to increased gene expression and secretion of inflammatory and growth promoting cytokines. Atherosclerosis 2004; 175:59-67. [PMID: 15186947 DOI: 10.1016/j.atherosclerosis.2004.02.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2003] [Revised: 02/12/2004] [Accepted: 02/27/2004] [Indexed: 11/18/2022]
Abstract
Radiation therapy is applied to inhibit neointima formation after percutaneous transluminal coronary angioplasty (PTCA). In this study, we evaluated the effect of irradiation on re-endothelialisation of circular denuded tracks made in post-confluent cultures of arterial endothelial cells (ECs) and on cellular factors involved in this process. Image analysis and time-lapse microcinematography revealed cell migration into denuded areas starting 4h after injury. Fifty percent coverage was achieved at 14.8 +/- 2.0 h. Using competitive PCR and flow cytometry techniques, no significant changes in mRNA expression of interleukin-1beta (IL-1beta), interleukin-8 (IL-8), basic fibroblast growth factor (bFGF or FGF-2), transforming growth factor-beta1 (TGF-beta1), platelet-derived growth factor A (PDGF-A), platelet-derived growth factor B (PDGF-B) and tissue factor (TF), and surface molecule expression of anti-intercellular adhesion molecule-1 (ICAM-1), anti-vascular cell adhesion molecule-1 (VCAM-1), anti-platelet/endothelial cell adhesion molecule-1 (PECAM-1), MHC-1, TF and Fas were observed. However, injury did significantly (P < 0.05) elevate the release of IL-8 and FGF-2 protein in the cell culture supernatant, as assessed by ELISA. Radiation (15Gy) given immediately after injury did not affect the kinetics of re-endothelialisation up to 48 h, in spite of the fact that no cell divisions were observed. Thereafter cell density decreased and cultures deteriorated. Compared to cultures exposed to injury alone, radiation induced significant (P < 0.05) increases in mRNA levels of IL-8 (1.35 +/- 0.10-fold increase at 4h), FGF-2 (1.62 +/- 0.10-fold at 4h; 1.76 +/- 0.33-fold at 24h) and IL-1beta (2.76 +/- 0.40-fold at 24h), whereas mRNA levels of TGF-beta1, PDGF-A and PDGF-B increased about 1.2-fold. IL-8 and FGF-2 protein concentrations in the media were higher than those observed in non-irradiated injured cell cultures; however, this difference was not significant. Radiation induced a 2.3 +/- 0.3-fold increase (P < 0.05) in Fas surface expression only. In conclusion, irradiation of mechanically-injured human EC leads to increased gene expression and protein secretion of inflammatory and growth promoting cytokines.
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Mankee A, Ali S, Chin A, Indalsingh R, Khan R, Mohammed F, Rahman R, Sooknanan S, Tota-Maharaj R, Simeon D, Adesiyun A. Bacteriological quality of “doubles” sold by street vendors in Trinidad and the attitudes, knowledge and perceptions of the public about its consumption and health risk. Food Microbiol 2003. [DOI: 10.1016/s0740-0020(03)00032-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Chin A, Radhakrishnan J, Fornell L, John E. Effects of tezosentan, a dual endothelin receptor antagonist, on the cardiovascular and renal systems of neonatal piglets. J Pediatr Surg 2001; 36:1824-8. [PMID: 11733915 DOI: 10.1053/jpsu.2001.28852] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND/PURPOSE Endothelin is a potent biological vasoactive mediator in the cardiovascular and renal systems. Little is known of the effects of endothelin antagonism on the developing heart and kidney, and we hope to show that endothelin does have an important role in the cardiovascular and renal systems of the developing neonate. In this study the authors have examined the effects of tezosentan, a nonselective endothelin-A and endothelin-B receptor antagonist designed for parenteral use, on the cardiovascular and renal systems of healthy neonatal piglets. METHODS Eight, 7- to 10-day old domestic piglets weighing 2.5 to 3.0 kg were anesthetized, intubated, and ventilated with catheters placed into the jugular vein, left ventricle, and femoral artery. Urine output was monitored via a suprapubic cystostomy. After baseline data were obtained the piglets received tezosentan (1 mg/kg/h) for 1 hour. A set of data was collected just before discontinuation of the 1-hour infusion of tezosentan and another set was collected 1 hour after the discontinuation of the drug. Mean arterial pressure (MAP), heart rate (HR), and urine output (UV) were monitored continuously and cardiac index (CI), systemic vascular resistance (SVR), renal blood flow (RBF), and renal vascular resistance (RVR) were calculated from gamma counts obtained from injections of radio-labeled microspheres at end of the different time periods. Glomerular filtration rate (GFR) was obtained by the sodium iothalamate method. Data were averaged and plotted versus time and analyzed statistically by a Student's t test. RESULTS (P <.05 versus baseline*). In our experimental animals the infusion of tezosentan diminished MAP and SVR from baseline values of 94 +/- 7 mm Hg and 0.14 +/- 0.03 mm Hg/mL/min, respectively to TEZO values of 62 +/- 4* mm Hg and 0.07 +/- 0.02* mm Hg/mL/min. CI increased from 278 +/- 58 to 367 +/- 75* mL/min/kg with tezosentan. There also was a statistically significant increase in RBF from 1.16 +/- 0.38 to 1.86 +/- 0.37* mL/min/kg, an increase in UV from 0.57 +/- 0.24 to 0.64 +/- 0.12* mL/min, a decrease in RVR from 4.60 +/- 1.47 to 2.03 +/- 0.36* mm Hg/mL/min, and no change in the GFR. CONCLUSIONS The inhibition of endothelin receptors with tezosentan produced a statistically significant effect on the piglet cardiovascular system with a drop in MAP and SVR and an increase in CI and HR. It also produced a statistically significant increase in RBF and UV and a decrease in RVR without affecting GFR. J Pediatr Surg 36:1824-1828.
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Gryaznov S, Pongracz K, Matray T, Schultz R, Pruzan R, Aimi J, Chin A, Harley C, Shea-Herbert B, Shay J, Oshima Y, Asai A, Yamashita Y. Telomerase inhibitors--oligonucleotide phosphoramidates as potential therapeutic agents. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2001; 20:401-10. [PMID: 11563055 DOI: 10.1081/ncn-100002314] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We have designed, synthesized, and evaluated using physical, chemical and biochemical assays various oligonucleotide N3'-->P5' phosphoramidates, as potential telomerase inhibitors. Among the prepared compounds were 2'-deoxy, 2'-hydroxy, 2'-methoxy, 2'-ribo-fluoro, and 2'-arabino-fluoro oligonucleotide phosphoramidates, as well as novel N3'-->P5' thio-phosphoramidates. The compounds demonstrated sequence specific and dose dependent activity with IC50 values in the sub-nM to pM concentration range.
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Swindale NV, Stjepanovic G, Chin A, Mikelberg FS. Automated analysis of normal and glaucomatous optic nerve head topography images. Invest Ophthalmol Vis Sci 2000; 41:1730-42. [PMID: 10845593] [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] Open
Abstract
PURPOSE To classify images of optic nerve head (ONH) topography obtained by scanning laser ophthalmoscopy as normal or glaucomatous without prior manual outlining of the optic disc. METHODS The shape of the ONH was modeled by a smooth two-dimensional surface with a shape described by 10 free parameters. Parameters were adjusted by least-squares fitting to give the best fit of the model to the image. These parameters, plus others derived from the image using the model as a basis, were used to discriminate between normal and abnormal images. The method was tested by applying it to ONH topography images, obtained with the Heidelberg Retina Tomograph, from 100 normal volunteers and 100 patients with glaucomatous visual field damage. RESULTS Many of the parameters derived from the fits differed significantly between normal and glaucomatous ONH images. They included the degree of surface curvature of the disc region surrounding the cup, the steepness of the cup walls, the goodness-of-fit of the model to the image in the cup region, and measures of cup width and cup depth. The statistics of the parameters were analyzed and were used to construct a classifier that gave the probability, P(G), that each image came from the glaucoma population. Images were classified as abnormal if P(G) > 0.5. The probabilities assigned to each image were in most cases close to 0 (normal) or 1 (abnormal). Eighty-seven percent of the sample was confidently classified with P(G) < 0.3 or P(G) > 0.7. Within this group, the overall classification accuracy was 92%. The overall accuracy of the method (the mean of sensitivity and specificity, which were similar) in the whole sample was 89%. CONCLUSIONS ONH images can be classified objectively and dependably by an automated procedure that does not require prior manual outlining of disc boundaries.
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