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DNA sequence representation by trianders and determinative degree of nucleotides

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2005年第8期6卷 743-755页

作者： DUPLIJ Diana DUPLIJ steven Institute of Molecular Biology and genetics Kiev 03143 UkraineTheory Group Nuclear Physics LaboratoryKharkov National UniversityKharkov 61077 Ukraine

A new version of DNA walks, where nucleotides are regarded unequal in their contribution to a walk is introduced, which allows us to study thoroughly the “fine structure” of nucleotide sequences. The approach is based on the assumption that nucleotides have an inner abstract characteristic, the determinative degree, which reflects genetic code phenomenological prop-erties and is adjusted to nucleotides physical properties. We consider each codon position independently, which gives three separate walks characterized by different angles and lengths, and that such an object is called triander which reflects the “strength” of branch. A general method for identifying DNA sequence “by triander” which can be treated as a unique “genogram” (or “gene passport”) is proposed. The two- and three-dimensional trianders are considered. The difference of sequences fine structure in genes and the intergenic space is shown. A clear triplet signal in coding sequences was found which is absent in the intergenic space and is independent from the sequence length. This paper presents the topological classification of trianders which can allow us to provide a detailed working out signatures of functionally different genomic regions.

关键词： DNA walk Triander Determinative degree Analysis DNA sequences Dystrophin Nucleotide

c-Met signaling in the development of tumorigenesis and chemoresistance: Potential applications in pancreatic cancer

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World Journal of gastroenterology 2014年第26期20卷 8458-8470页

作者： Daniel Delitto Eva Vertes-george steven J Hughes Kevin E Behrns Jose g Trevino Department of Surgery University of Florida-Gainesville Department of Pathology University of Florida-Gainesville

Pancreatic ductal adenocarcinoma is the 4th leading cause of cancer deaths in the United States. The majority of patients are candidates only for palliative chemotherapy, which has proven largely ineffective in halting tumor progression. One proposed mechanism of chemoresistance involves signaling via the mesenchymal-epithelial transition factor protein (MET), a previously established pathway critical to cell proliferation and migration. Here, we review the literature to characterize the role of MET in the development of tumorigenesis, metastasis and chemoresistance, highlighting the potential of MET as a therapeutic target in pancreatic cancer. In this review, we characterize the role of c-Met in the development of tumorigenesis, metastasis and chemoresistance, highlighting the potential of c-Met as a therapeutic target in pancreatic cancer.

关键词： Pancreatic adenocarcinoma c-Met Chemoresistance Receptor tyrosine kinase

Colonic ulcerations may predict steroid-refractory course in patients with ipilimumab-mediated enterocolitis

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World Journal of gastroenterology 2017年第11期23卷 2023-2028页

作者： Animesh Jain Evan J Lipson William H Sharfman steven R Brant Mark g Lazarev Division of gastroenterology and Hepatology Department of Internal MedicineUniversity of North Carolina Chapel Hill Department of Oncology Johns Hopkins University School of Medicine and Sidney Kimmel Comprehensive Cancer Center Division of gastroenterology and Hepatology Department of Internal MedicineJohns Hopkins University School of Medicine

AIM To investigate management of patients who develop ipilimumab-mediated enterocolitis, including association of endoscopic findings with steroid-refractory symptoms and utility of infliximab as second-line *** We retrospectively reviewed all patients at our centerwith metastatic melanoma who were treated with ipilimumab between March 2011 and May 2014. All patients received a standard regimen of intravenous ipilimumab 3 mg/kg every 3 wk for four doses or until therapy was stopped due to toxicity or disease progression. Basic demographic and clinical data were collected on all patients. For patients who developed grade 2 or worse diarrhea(increase of 4 bowel movements per day), additional data were collected regarding details of gastrointestinal symptoms, endoscopic findings and treatment course. Descriptive statistics were *** A total of 114 patients were treated with ipilimumab during the study period and all were included. Sixteen patients(14%) developed ≥ grade 2 diarrhea. All patients were treated with high-dose corticosteroids(1-2 mg/kg prednisone daily or equivalent). Nine of 16 patients(56%) had ongoing diarrhea despite highdose steroids. Steroid-refractory patients received one dose of intravenous infliximab at 5 mg/kg, and all but one had brisk resolution of diarrhea. Fourteen of the patients underwent either colonoscopy or sigmoidoscopy with variable endoscopic findings, ranging from mild erythema to colonic ulcers. Among 8 patients with ulcers demonstrated by sigmoidoscopy or colonoscopy, 7 patients(88%) developed steroidrefractory symptoms requiring infliximab. With a median follow-up of 264 d, no major adverse events associated with prednisone or infliximab were *** In patients with ipilimumab-mediated enterocolitis, the presence of colonic ulcers on endoscopy was associated with a steroid-refractory course.

关键词： Ipilimumab Melanoma Enterocolitis Colitis Infliximab Corticosteroid Colonic ulcer

Hemoglobin Adducts as Biomarkers of Exposure to and metabolic Activation of Carcinogenic Tobacco-Specific Nitrosamines

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Biomedical and Environmental Sciences 1991年第1期4卷 93-103页

作者： STEPHEN S.HECHT steven g.CARMELLA SHARON E.MURPHY Dana Road American Health Foundation ValhallaDana Road American Health Foundation ValhallaDana Road American Health Foundation Valhalla New York 10595New York 10595 New York 10595

The carcinogenic tobacco-specific nitrosamines N-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-l-(3-pyridyl)-l-butanone (NNK) form hemoglobin adducts in laboratory animals and humans. These adducts release 4-hydroxy-l-(3-pyridyl)-l-butanone (HPB) upon mild base hydrolysis. HPB released from human hemoglobin can be quantified by gas chromatography-mass spectrometry. It is the only available biochemical marker for determination of exposure to, and metabolic activation of, carcinogens present only in tobacco. Levels of HPB were highest in snuff-dippers, followed by smokers and nonsmokers. Large interindividual variations in adduct levels were observed. The relationship between HPB levels in globin and DNA of rats treated with NNK has been investigated in order to aid in interpretation of the data from humans. These studies have provided the initial database for understanding the metabolic activation of tobacco-specific nitrosamines in humans.

关键词： Hemoglobin Adducts as Biomarkers of Exposure to and metabolic Activation of Carcinogenic Tobacco-Specific Nitrosamines

Cytomegalovirus retinitis in the highly active anti-retroviral therapy era

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Annals of Eye Science 2022年第1期7卷 42-50页

作者： Ifeoma N.Ude steven Yeh Jessica g.Shantha Morehouse School of Medicine AtlantaGAUSA Francis I.Proctor Foundation University of CaliforniaSan FranciscoCAUSA Truhlsen Eye Institute University of Nebraska Medical CenterOmahaNEUSA

Cytomegalovirus(CMV)retinitis is an opportunistic infection that has traditionally affected those who have HIV/AIDS or immunosuppressed *** retinitis previously infected one-third of AIDS patients in the pre-highly active antiretroviral therapy(HAART)era,but since HAART,Western countries have seen an 80%decrease in the incidence of the *** recently,CMV retinitis has been reported in patients who are immunosuppressed,often due to chemotherapy or immunomodulatory *** diagnosis of CMV retinitis is often suspected based on clinical findings,with polymerase chain reaction for confirmation of CMV,especially in atypical *** active antiretroviral therapy and anti-CMV medications(systemic or local)remain the mainstay of ***,for those who are not responsive to HAART,CMV retinitis remains a challenge,and can still lead to significant vision ***,a regimen of anti-CMV medications can sometimes lead to viral resistance or organ *** such as immune recovery retinitis and rhegmatogenous retinal detachments continue to threaten the vision of patients who develop CMV *** complications can arise following initiation of treatment or if patients show disease *** vision screening for CMV retinitis in immunosuppressed patients at-risk is necessary for early detection and treatment.

关键词： Cytomegalovirus(CMV) retinitis highly active antiretroviral therapy(HAART)

Breath volatile organic compounds for the gut-fatty liver axis: promise, peril, and path forward

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World Journal of gastroenterology 2014年第27期20卷 9017-9025页

作者： steven Francis Solga Solga gastroenterology Bethlehem PA 18015 United States

The worldwide interest in the gut microbiome and its impact on the upstream liver highlight a critical upside to breath research: it can uniquely measure otherwise unmeasurable biology. Bacteria make gases [volatile organic compounds(VOCs)] that are directly relevant to pathophysiology of the fatty liver and associated conditions, including obesity. Measurement of these VOCs and their metabolites in the exhaled breath, therefore, present an opportunity to safely and easily evaluate, on both a personal and a population level, some of our most pressing public health threats. This is an opportunity that must be pursued. To date, however, breath analysis remains a slowly evolving field which only occasionally impacts clinical research or patient care. One major obstacle to progress is that breath analysis is inherently and emphatically mutli-disciplinary: it connects engineering, chemistry, breath mechanics, biology and medicine. Unbalanced or incomplete teams may produce inconsistent and often unsatisfactory results. A second impediment is the lack of a well-known stepwise structure for the development of non-invasive diagnostics. As a result, the breath research landscape is replete with orphaned single-center pilot studies. Often, important hypotheses and key observations have not been pursued to maturation. This paper reviews the rationale and requirements for breath VOC research applied to the gut-fatty liver axis and offers some suggestions for future development.

关键词： Breath Volatile organic compounds Fatty liver gut flora Breath analysis

Eastern Asian endemic seed plant genera and their paleogeographic history throughout the Northern Hemisphere

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Journal of Systematics and Evolution 2009年第1期47卷 1-42页

作者： steven R.MANCHESTER Kazuhiko UEMURA Florida Museum of Natural History University of Florida National Museum of Nature and Science

We review the fossil history of seed plant genera that are now endemic to eastern Asia. Although the majority of eastern Asian endemic genera have no known fossil record at all, 54 genera, or about 9%, are reliably known from the fossil record. Most of these are woody (with two exceptions), and most are today either broadly East Asian, or more specifically confined to Sino-Japanese subcategory rather than being endemic to the Sino-Himalayan area. Of the "eastern Asian endemic" genera so far known from the fossil record, the majority formerly occurred in Europe and/or North America, indicating that eastern Asia served as a late Tertiary or Quaternary refugium for taxa. Hence, many of these genera may have originated in other parts of the Northern Hemisphere and expanded their ranges across continents and former sea barriers when tectonic and climatic conditions al- lowed, leading to their arrival in eastern Asia. Although clear evidence for paleoendemism is provided by the gymnosperms Amentotaxus, Cathaya, Cephalotaxus, Cunninghamia, Cryptomeria, glyptostrobus, ginkgo, Ketel-eeria, Metasequoia, Nothotsuga, Pseudolarix, Sciadopitys, and Taiwania, and the angiosperms Cercidiphyllum, Choerospondias, Corylopsis, Craigia, Cyclocarya, Davidia, Dipelta, Decaisnea, Diplopanax, Dipteronia, Em-menopterys, Eucommia, Euscaphis, Hemiptelea, Hovenia, Koelreuteria, Paulownia, Phellodendron, Platycarya, Pteroceltis, Rehderodendron, Sargentodoxa, Schizophragma, Sinomenium, Tapiscia, Tetracentron, Toricellia, Trapella, and Trochodendron, we cannot rule out the possibility that neoendemism plays an important role especially for herbaceous taxa in the present-day flora of Asia, particularly in the Sino-Himalayan region. In addition to reviewing paleobotanical occurrences from the literature, we document newly recognized fossil occurrences that expand the geographic and stratigraphic ranges previously known for Dipelta, Pteroceltis, and Toricellia.

关键词： Cretaceous eastern Asia endemic paleobotany phytogeography Tertiary

Recent advances in the management of hyponatremia in cancer patients

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Journal of Cancer Metastasis and Treatment 2019年第10期4卷 21-32页

作者： Maryam I.Khan steven g.Waguespack Intekhab Ahmed Division of Endocrinology Diabetes and MetabolismJefferson HealthVoorheesNJ 08043USA Department of Endocrine Neoplasia and Hormonal disorders University of Texas M.D.Anderson Cancer CenterHoustonTX 77030USA Division of Endocrinology Diabetes and MetabolismJefferson HealthPhiladelphiaPA 19107USA.

Hyponatremia is the most frequently encountered electrolyte disorder in cancer patients and is usually multifactorial in its *** this review,we discuss the predisposing factors,pathophysiology,clinical symptomatology,and currently available diagnostic and therapeutic options for the management of *** addition to paraneoplastic syndromes,concurrent chemotherapy and comorbidities predispose oncology patients to the risk of *** symptoms and signs can be subtle and the prompt evaluation and initiation of treatment is of paramount importance to prevent neurocognitive and other *** syndrome of inappropriate antidiuresis(SIAD)is the most common cause of hyponatremia,and the use of serum and urine parameters that distinguish SIAD from other etiologies is *** treatment is preferred depending on the underlying cause and severity of *** treatment of hyponatremia is reviewed and the importance of avoiding rapid overcorrection of the sodium level to reduce the risk of osmotic demyelination syndrome is *** receptor antagonists(vaptans)offer a direct approach to the management of euvolemic and hypervolemic hyponatremia,but the indications for their use and long-term safety need to be *** treatment of hyponatremia is likely to reduce complications and improve survival in cancer patients.

关键词： Hyponatremia electrolyte abnormalities dysnatremias cancer

Type Ⅱ codes over finite rings

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Science China Mathematics 2010年第1期53卷 203-212页

作者： DOUgHERTY steven T Department of Mathematics University of Scranton ScrantonPA 18510 USA

In this paper,we generalize the concept of Type Ⅱ codes to arbitrary finite rings. We focus on Type Ⅱ codes over finite chain rings and use the Chinese Remainder Theorem on these codes to study Type Ⅱ codes over pr... 详细信息

关键词： finite principal ideal rings finite chain rings self-dual codes Type Ⅱ codes