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Search Results: 1 - 10 of 221031 matches for " Alfred C Feller "
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Sensitive and reliable detection of Kit point mutation Asp 816 to Val in pathological material
Christian K?hler, Sabine Didlaukat, Alfred C Feller, Hartmut Merz
Diagnostic Pathology , 2007, DOI: 10.1186/1746-1596-2-37
Abstract: The Kit point mutation Asp 816 to Val is heterozygous which means a problem in detection by PCR because the wild-type allele is also amplified and the number of cells which bear the point mutation is in most of the cases low. Most PCR protocols use probes to block the wild-type allele during amplification with more or less satisfying result. This is why point-mutated forward primers were designed and tested for efficiency in amplification of the mutated allele.One primer combination (A) fits the most for the introduced PCR assay. It was able just to amplify the mutated allele with high specificity from different patient's materials (FFPE or blood) of varying quality and quantity. Moreover, the sensitivity for this assay was convincing because 10 ng of DNA which bears the point mutation could be detected in a total volume of 200 ng of DNA.The PCR assay is able to deal with different materials (blood and FFPE) this means quality and quantity of DNA and can be used for high-througput screening because of its robustness. Moreover, the method is easy-to-use, not labour-intensive, and easy to realise in a standard laboratory.1,000 to 8,000 incidences of human mastocytosis are reported every year in the US [1]. Human mastocytosis is characterised by accumulation of mast cells in different organs. It is a heterogenous group of disorders which can be divided into the categories cutaneous mastocytosis (CM) and systemic mastocytosis (SM) which is commonly seen in adults by histological lesions in the bone marrow and other non-cutaneous organs [2,3]. SM can be further divided into the categories indolent systemic mastocytosis (ISM), SM with an associated clonal hematologic non-mast cell lineage disease (AHNMD), aggressive sytemic mastocytosis (ASM), and mast cell leukemia (MCL). ISM is the most common form which involves skin, bone marrow, and GI tract with good prognosis for the patient. First relations between mastocytosis and activating mutations in the receptor tyrosine kin
Gastrointestinal stromal tumors with pseudocystic change mimicking a pancreatic tumor: two case reports
Ursula Pauser, Sebastian Hinz, Hartmut Merz, Alfred C Feller
Journal of Medical Case Reports , 2009, DOI: 10.1186/1752-1947-3-7592
Abstract: A 51-year-old woman and a 65-year-old man, both German, presented with abdominal cystic lesions suspected to be pancreatic pseudocysts. Both tumors were classified as gastrointestinal stromal tumors, epithelioid subtype. In one case, tumor origin in the gastric wall was confirmed by relaparotomy. In the other case, a point mutation in PDGFRalpha gene, exon 18 proved the diagnosis of gastrointestinal stromal tumor. The tumors were resected and both patients are still alive and disease-free.The differential diagnosis of cystic lesions in the upper abdomen must include gastrointestinal stromal tumors with pseudocystic change. The origin of a large cystic gastrointestinal stromal tumor may be difficult to determine. Epithelioid tumor pattern, weak or absent KIT expression and detection of PDGFRalpha mutation are typical diagnostic parameters of gastric gastrointestinal stromal tumors.Cystic lesions of the pancreas are usually pseudocysts, related to chronic pancreatitis. Some are inflammatory pseudotumors with regressive cystic change; others are solid-pseudopapillary tumors or serous or mucinous cystic neoplasms of the pancreas.The diagnostic spectrum of pancreatic cystic lesions has been well investigated. Recently, we introduced a new entity entitled solid and cystic pancreatic hamartomas with a review of the literature [1]. The diagnoses and malignant potential of cystic lesions are sometimes difficult to predict, but in general, they are simply classified by their histology. The following cases demonstrate pancreatic cystic lesions that secondarily involved the pancreas. The histological, immunohistochemical and molecular investigation led to the diagnosis of gastrointestinal stromal tumor (GIST) with pseudocystic change. The difficulties of tumor diagnosis and tumor origin are discussed.A 51-year-old woman presented with a palpable abdominal mass on physical examination. From a computed tomography (CT) scan, a cystic tumor, 20 cm in diameter, was notes to be prese
P53 expression is significantly correlated with high risk of malignancy and epithelioid differentiation in GISTs. An immunohistochemical study of 104 cases
Ursula Pauser, Nina Schmedt auf der Günne, Günter Kl?ppel, Hartmut Merz, Alfred C Feller
BMC Cancer , 2008, DOI: 10.1186/1471-2407-8-204
Abstract: We investigated 104 KIT positive GISTs from various tumor sites in immunoassays on CD34, Ki67 and particularly on P53, BCL-2 and Cyclin D1. The results were compared with tumor size, mitotic rate, proliferative activity, histological subtype, nuclear atypia and risk assessment according to Fletcher and Miettinen. Occurrence of metastases and survival were also taken into account.The expression of P53 was significantly correlated with high risk criteria towards malignancy and epithelioid differentiation in GISTs. Likewise P53 label correlated significantly with the established prognostic indicators: tumor size, mitotic rate, nuclear atypia and proliferative activity. Regarding the site of tumor presentation, P53 was not a decisive factor. BCL-2 and Cyclin D1 expression was not related to any of the prognostic indicators.The present data identified P53 being a recommendable marker for predicting the risk of malignancy in GISTs. In addition, we found P53 significantly correlated with epithelioid tumor differentiation, independent of tumor site. BCL-2 and Cyclin D1, however, did not prove to be deciding markers for diagnosis and prognosis.In recent years, progress has been achieved in establishing accurate diagnoses of gastrointestinal stromal tumors (GISTs), elucidating their molecular pathogenesis and developing a specific treatment. GISTs are defined as mesenchymal tumors of stomach and intestine that express KIT (CD117) and show either a c-kit mutation or a mutation in the gene that encodes the platelet-derived growth factor receptor alpha (PDGFRα) [1-3]. Mutations in both genes lead to ligand independent dimerization of transmembrane tyrosine kinase receptor type III and to intracytoplasmic signal transduction via phosphorylation of tyrosine kinase [4-7]. The tyrosine kinase receptor inhibitor imatinib (Glivec ?) has proven to be highly successful for the treatment of metastasized GISTs. Currently, (neo-) adjuvant imatinib therapy is being tested in order to minimi
Heterogeneity of CD4 and CD8+ memory T cells in localized and generalized Wegener's granulomatosis
Peter Lamprecht, Anika Erdmann, Antje Mueller, Elena Csernok, Eva Reinhold-Keller, Konstanze Holl-Ulrich, Alfred C Feller, Hilke Bruehl, Wolfgang L Gross
Arthritis Research & Therapy , 2002, DOI: 10.1186/ar610
Abstract: Wegener's granulomatosis (WG) is an autoimmune disease of unknown etiology characterized by granulomatous and vasculitic lesions. Localized WG, in which granulomatous lesions are restricted to the respiratory tract, may precede 'classical' generalized WG. Observation of a disease course of localized WG without progression for several years has remained a rare finding [1]. The disease usually progresses to generalized WG, in which clinical manifestations of frank autoimmune vasculitis prevail, for example pulmonary–renal syndrome. An autoantibody, namely antineutrophil cytoplasmic antibody specific for proteinase 3 (PR3-ANCA), is detected in the vast majority of patients with generalized WG [1,2]. Whereas granulomatous lesions express predominantly T helper type 1 (Th1)-type cytokines in localized WG [3], a shift towards stronger Th2-type cytokine expression is found in granulomatous lesions of the respiratory tract in generalized WG [3,4]. In kidney lesions of generalized WG, the expression of both Th1-type and Th2-type cytokine and chemokine receptors has been described. Thus, the local cytokine milieu might depend on the site and extent of disease activity [4,5]. The shift in the cytokine profile in granulomatous lesions of the respiratory tract might be of importance for disease progression [2,3].The term effector memory T cells has been used to denote memory T cells that display migratory properties, readily produce cytokines and release granular contents [6-8]. These cells show striking tissue selectivity of migration and are preferentially recruited to sites of inflammation [7,8]. The phenotype of memory T cells is heterogeneous. A fraction of CD45RO+ (positive for the short human isoform of CD45) memory T cells reverts to the phenotype CD45RA+ (positive for the long human isoform of CD45) [9]. Antigen-experienced T cells, for example virus-specific T cells, were found to display considerable heterogeneity with regard to their CD45 isoform expression [10,11].
Trends in precipitation and streamwater chemistry in East Creek watershed in southwestern British Columbia, 1971–2008
Michael C. FELLER
Journal of Limnology , 2010, DOI: 10.4081/jlimnol.2010.s1.77
Abstract: Bulk precipitation and streamwater in a small, undisturbed, forested watershed in southwestern British Columbia were sampled regularly and analyzed for dissolved chemical constituents from 1971 to 2008. Concentrations and fluxes of most chemicals in precipitation and streamwater have exhibited considerable yearly variation. Temporal trends, when they have occurred, have rarely been consistent for the entire 1972–2008 time period. Precipitation has exhibited a decline in electrical conductivity, a decline in NH4, inorganic-N, and total-N concentrations and fluxes since the 1980s, an increase in pH, a decline in acid H fluxes since ~1990, and a decrease in SO4 concentrations and fluxes from 1980 until the late 1990s. Streamwater has exhibited an increase in NO3 concentrations and fluxes until the late 1990s, an increase in pH and decrease in acid H fluxes since the early 1990s, a decrease in SO4 concentrations and fluxes from ~1980 until ~2000, and increases in Na and Cl concentrations and fluxes until ~2000. Critical precipitation SO4 and inorganic-N loads have probably been exceeded for most years. East Ck. watershed has continuously experienced net inflows of all forms of N and acid H, and net outflows of dissolved Si, Na, Mg, and Ca. Net inflows of inorganic forms of N and total-N have decreased since the early 1980s. Net acid H inflows have decreased since the early 1990s, while net Na and Cl outflows increased until ~2000. The contribution of nutrient cycling processes within the watershed to the changes is currently unknown.
Application of Tikhonov Regularization Technique to the Kinetic Data of an Autocatalytic Reaction: Pyrolysis of N-Eicosane  [PDF]
Sunday C. Omowunmi, Alfred A. Susu
Engineering (ENG) , 2011, DOI: 10.4236/eng.2011.312145
Abstract: A new technique based on Tikhonov regularization, for converting time-concentration data into concentration-reaction rate data, was applied to a novel pyrolysis investigation carried out by Susu and Kunugi [1]. The reaction which involves the thermal decomposition of n-eicosane using synthesis gas for K2CO3-catalyzed shift reaction was reported to be autocatalytic. This result was confirmed by applying Tikhonov regularization to the experimental data (conversion vs. time) presented by Susu and Kunugi [1]. Due to the ill-posed nature of the problem of obtaining reaction rates from experimental data, conventional methods will lead to noise amplification of the experimental data. Hence, Tikhonov regularization is preferably employed because it is entirely independent of reaction rate model and it also manages to keep noise amplification under control, thus, leading to more reliable results. This is shown by the agreement of the kinetic parameters obtained using the resulting conversion-reaction rate profile, with the Ostwald-type process for autocatalysis suggested by Susu and Kunugi [1].
Oral Squamous Cell Carcinoma: Epidemiology, Clinical Presentation and Treatment  [PDF]
Liviu Feller, Johan Lemmer
Journal of Cancer Therapy (JCT) , 2012, DOI: 10.4236/jct.2012.34037
Abstract: Squamous cell carcinoma accounts for 90% of all oral cancers. It may affect any anatomical site in the mouth, but most commonly the tongue and the floor of the mouth. It usually arises from a pre-existing potentially malignant lesion, and occasionally de novo; but in either case from within a field of precancerized epithelium. The use of tobacco and betel quid, heavy drinking of alcoholic beverages and a diet low in fresh fruits and vegetables are well known risk factors for oral squamous cell carcinoma. Important risk factors related to the carcinoma itself that are associated with a poor prognosis include large size of the tumour at the time of diagnosis, the presence of metastases in regional lymphnodes, and a deep invasive front of the tumour. Squamous cell carcinoma is managed by surgery, radiation, and chemotherapy singularly or in combination; but regardless of the treatment modality, the five-year survival rate is poor at about 50%. This can be attributed to the fact that about two-thirds of persons with oral squamous cell carcinoma already have a large lesion at the time of diagnosis.
Fossil Cynipid
Alfred C. Kinsey
Psyche , 1919, DOI: 10.1155/1919/96156
Abstract:
An African Figitid
Alfred C. Kinsey
Psyche , 1919, DOI: 10.1155/1919/16737
Abstract:
Paucity of immune complexes in skin lesions of lichen planus
Srinivas C,Alfred Sandra
Indian Journal of Dermatology, Venereology and Leprology , 1996,
Abstract:
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