| 1. |
- Andersson, Patiyan, 1978-, et al.
(författare)
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PIK3CA, HRAS and KRAS gene mutations in human penile cancer
- 2008
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Ingår i: Journal of Urology. - New York, USA : Ovid Technologies (Wolters Kluwer Health). - 0022-5347 .- 1527-3792. ; 179:5, s. 2030-2034
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The knowledge of somatic mutations that arise in penile cancer is limited. We examined the dysregulation of components in the phosphatidylinositol 3-kinase and Ras pathways. Materials and Methods: Using single stranded conformational analysis and direct sequencing we performed mutational analysis of the PIK3CA, PTEN, HRAS, KRAS, NRAS and BRAF genes in 28 penile tumors. Results: We identified somatic missense mutations in 11 of the 28 penile cancer samples (39%). In the PIK3CA gene 8 mutations (29%) were identified that were E542K or E545K. In the HRAS gene a G12S and a Q61L mutation were found (7%). The KRAS gene contained 1 mutation (3%), that is a G12S change. PIK3CA mutations were found in all grades and stages, whereas HRAS and KRAS mutations were found in larger and more advanced tumors. The mutations were mutually exclusive, suggesting that dysregulation of either pathway is sufficient for the development and progression of penile carcinoma. Conclusions: The high frequency of mutations in the PIK3CA, HRAS and KRAS genes leads us to believe that dysregulation of the phosphatidylinositol 3-kinase or Ras pathway is significant for the development and progression of penile carcinoma.
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| 2. |
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| 3. |
- Aho, Leena, et al.
(författare)
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Systematic appraisal using immunohistochemistry of brain pathology in aged and demented subjects.
- 2008
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 25:5, s. 423-32
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/AIMS: Abnormal processing of hyperphosphorylated tau (HPtau), amyloid-beta (Abeta) and alpha-synuclein (alphaS) proteins is considered as causative with regard to the clinical symptoms in age-related neurodegenerative diseases.METHODS: In this retrospective, postmortem study applying immunohistochemical methodology, we assessed Alzheimer's-disease (AD)-related HPtau and Abeta pathology in 178 subjects with alphaS pathology.RESULTS: These pathologies were frequently seen concomitantly, i.e. HPtau in 83% and Abeta in 62% of the alphaS-positive cases. Furthermore, the striatum was frequently involved, particularly in subjects with cognitive impairment (65%). The predictive value of widespread HPtau pathology, i.e. stages V-VI, with respect to cognitive impairment was high, since all 18 subjects presenting with this stage were demented. In contrast, the predictive value of widespread alphaS pathology, i.e. stages 5-6 according to Braak's Parkinson disease staging, was debatable. Fifty-three percent of the subjects with widespread alphaS pathology and no or mild AD-related HPtau pathology were cognitively unimpaired. It is noteworthy that striatal Abeta pathology was more often seen in demented subjects independently of HPtau and/or alphaS status.CONCLUSION: The causative pathology in subjects with clinically diagnosed dementia with Lewy bodies needs to be clarified in future studies.
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| 4. |
- Alafuzoff, Irina, et al.
(författare)
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Assessment of alpha-synuclein pathology : a study of the BrainNet Europe Consortium.
- 2008
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Ingår i: Journal of Neuropathology and Experimental Neurology. - : Oxford University Press (OUP). - 0022-3069 .- 1554-6578. ; 67:2, s. 125-43
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Tidskriftsartikel (refereegranskat)abstract
- To determine the reliability of assessment of alpha-synuclein-immunoreactive (alphaS-IR) structures by neuropathologists, 28 evaluators from 17 centers of BrainNet Europe examined current methods and reproducibility of alphaS-IR evaluation using a tissue microarray (TMA) technique. Tissue microarray blocks were constructed of samples from the participating centers that contained alphaS-IR structures. Slides from these blocks were stained in each center and assessed for neuronal perikaryal inclusions, neurites, and glial cytoplasmic inclusions. The study was performed in 2 phases. First, the TMA slides were stained with the antibody of the center's choice. In this phase, 59% of the sections were of good or acceptable quality, and 4 of 9 antibodies used performed consistently. Differences in interpretation and categorization of alphaS-IR structures, however, led to differing results between the laboratories. Prior to the second phase, the neuropathologists participated in a training session on the evaluation of alphaS-IR structures. Based on the results of the first phase, selected antibodies using designated antigen retrieval methods were then applied to TMA slides in the second phase. When the designated methods of both staining and evaluation were applied, all 26 subsequently stained TMA sections evaluated were of good/acceptable quality, and a high level of concordance in the assessment of the presence or absence of specific alphaS-IR structures was achieved. A semiquantitative assessment of alphaS-IR neuronal perikaryal inclusions yielded agreements ranging from 49% to 82%, with best concordance in cortical core samples. These results suggest that rigorous methodology and dichotomized assessment (i.e. determining the presence or absence of alphaS-IR) should be applied, and that semiquantitative assessment can be recommended only for the cortical samples. Moreover, the study demonstrates that there are limitations in the scoring of alphaS-IR structures.
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| 5. |
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| 6. |
- Alafuzoff, Irina, et al.
(författare)
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Inter-laboratory comparison of neuropathological assessments of beta-amyloid protein : a study of the BrainNet Europe consortium.
- 2008
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Ingår i: Acta Neuropathologica. - : Springer Science and Business Media LLC. - 0001-6322 .- 1432-0533. ; 115:5, s. 533-46
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid-beta-protein (Abeta) is generally assessed by neuropathologists in diagnostics. This BrainNet Europe ( http://www.brainnet-europe.org/ ) (15 centres and 26 participants) study was carried out to investigate the reliability of such an assessment. In the first part of this trial, tissue microarray sections were stained with the antibody of each centre's choice. Reflecting the reality, seven antibodies and a plethora of pretreatment strategies were used. Ninety-two percent of the stainings were of good/acceptable quality and the estimation of presence of Abeta aggregates yielded good results. However, a poor agreement was reached particularly regarding quantitative (density) and qualitative (diffuse/cored plaques) results. During a joint meeting, the clone 4G8 was determined to label best the fleecy/diffuse plaques, and thus, this clone and the formic acid pretreatment technique were selected for the second part of this study. Subsequently, all stained sections were of good/acceptable quality and again a high level of concordance of the dichotomized (presence/absence) assessment of plaques and CAA was achieved. However, even when only one antibody was used, the type of Abeta-aggregates (diffuse/cored), type of vessel and Vonsattel grade, were not reliably assigned. Furthermore, the quantification of lesions was far from reliable. In line with the first trial, the agreement while assessing density (some, moderate and many) was unimpressive. In conclusion, we can confirm the utility of immunohistochemical detection of Abeta-protein in diagnostics and research. It is noteworthy that to reach reproducible results a dichotomized assessment of Abeta-immunoreactivity rather than quantification and assignment of various types of lesions should be applied, particularly when comparing results obtained by different neuropathologists.
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| 7. |
- Alafuzoff, Irina, et al.
(författare)
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Staging of neurofibrillary pathology in Alzheimer's disease : a study of the BrainNet Europe Consortium.
- 2008
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Ingår i: Brain Pathology. - : Wiley. - 1015-6305 .- 1750-3639. ; 18:4, s. 484-96
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Tidskriftsartikel (refereegranskat)abstract
- It has been recognized that molecular classifications will form the basis for neuropathological diagnostic work in the future. Consequently, in order to reach a diagnosis of Alzheimer's disease (AD), the presence of hyperphosphorylated tau (HP-tau) and beta-amyloid protein in brain tissue must be unequivocal. In addition, the stepwise progression of pathology needs to be assessed. This paper deals exclusively with the regional assessment of AD-related HP-tau pathology. The objective was to provide straightforward instructions to aid in the assessment of AD-related immunohistochemically (IHC) detected HP-tau pathology and to test the concordance of assessments made by 25 independent evaluators. The assessment of progression in 7-microm-thick sections was based on assessment of IHC labeled HP-tau immunoreactive neuropil threads (NTs). Our results indicate that good agreement can be reached when the lesions are substantial, i.e., the lesions have reached isocortical structures (stage V-VI absolute agreement 91%), whereas when only mild subtle lesions were present the agreement was poorer (I-II absolute agreement 50%). Thus, in a research setting when the extent of lesions is mild, it is strongly recommended that the assessment of lesions should be carried out by at least two independent observers.
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| 8. |
- Bell, Jeanne E, et al.
(författare)
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Management of a twenty-first century brain bank : experience in the BrainNet Europe consortium.
- 2008
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Ingår i: Acta Neuropathologica. - : Springer Science and Business Media LLC. - 0001-6322 .- 1432-0533. ; 115:5, s. 497-507
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Tidskriftsartikel (refereegranskat)abstract
- Collections of human postmortem brains gathered in brain banks have underpinned many significant developments in the understanding of central nervous system (CNS) disorders and continue to support current research. Unfortunately, the worldwide decline in postmortem examinations has had an adverse effect on research tissue procurement, particularly from control cases (non-diseased brains). Recruitment to brain donor programmes partially addresses this problem and has been successful for dementing and neurodegenerative conditions. However, the collection of brains from control subjects, particularly from younger individuals, and from CNS disorders of sudden onset, remains a problem. Brain banks need to adopt additional strategies to circumvent such shortages. The establishment of brain bank networks allows data on, and access to, control cases and unusual CNS disorders to be shared, providing a larger resource for potential users. For the brain banks themselves, inclusion in a network fosters the sharing of protocols and development of best practice and quality control. One aspect of this collective experience concerns brain bank management, excellence in which is a prerequisite not only for gaining the trust of potential donors and of society in general, but also for ensuring equitable distribution to researchers of high quality tissue samples. This review addresses the legal, ethical and governance issues, tissue quality, and health and safety aspects of brain bank management and data management in a network, as well as the needs of users, brain bank staffing, donor programs, funding issues and public relations. Recent developments in research methodology present new opportunities for researchers who use brain tissue samples, but will require brain banks to adopt more complex protocols for tissue collection, preparation and storage, with inevitable cost implications for the future.
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| 9. |
- Blirup, Soren, et al.
(författare)
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Protein standardization V: value transfer. A practical protocol for the assignment of serum protein values from a Reference Material to a Target Material.
- 2008
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Ingår i: Clinical Chemistry and Laboratory Medicine. - 1434-6621. ; Sep 1, s. 1470-1479
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Tidskriftsartikel (refereegranskat)abstract
- Abstract We present a practical protocol for the assignment of values to serum proteins in a Target Material using a Reference Material. This protocol is based on the model of Direct Value Transfer between serum matrices and is intended to improve the value assignment of commercial calibrators using the Reference Material CRM 470 (now labeled ERM-DA 470) or similar reference materials. The procedure describes the general as well as the practical principles involved in the value assignment (with examples). The practical transfer protocol is based on multiple assays of 6 dilutions of the Reference Material and 6 dilutions of the Target Material. The transfer protocol requires several measurements a day repeated on several days, an important prerequisite being that all reconstitutions and dilutions are controlled by weighing thus reducing uncertainty in the transfer. In open systems that allow the use of the Reference Material as calibrator and the Target Material as samples, the proportionality of the two materials (the presence or absence of matrix effects) can now be directly assessed by evaluating a single regression plot. If no matrix effects are found, the regression line will pass through zero with a slope equal to the ratio of the concentrations of the two materials. In closed systems, the dedicated commercial calibrator has to be used as such; the Reference Material and the Target Material are now assayed as samples against this calibrator. Two regression plots are therefore obtained; if no matrix effects are present among the two materials and the calibrator, both the Reference and Target Materials will show zero intercepts, and the ratio of the two slopes will equal the ratio of the concentrations. Clin Chem Lab Med 2008;46.
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| 10. |
- Dahlbom, Ingrid, et al.
(författare)
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Protein A and protein G ELISA for the detection of IgG autoantibodies against tissue transglutaminase in childhood celiac disease
- 2008
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Ingår i: Clinica Chimica Acta. - : Elsevier BV. - 0009-8981 .- 1873-3492. ; 395:1-2, s. 72-6
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate if the detection of celiac disease (CD) in children was improved by using alternative conjugates for assessment of tissue transglutaminase (tTG) autoantibodies. Methods: Serum samples from 108 biopsy confirmed CD children and 42 control subjects were investigated for the presence of autoantibodies with tTG coated microplates using protein A (PA), protein G (PG), anti-IgG, or anti-IgA as conjugates. Results: Of the 108 CD children, 86 (80%) were IgG-tTG positive, 91 (84%) were positive with the PA-conjugate, 94 (87%) were positive with the PG-conjugate, and 103 (95%) were IgA-tTG positive. Among the 42 controls. 4 (10%) were IgG-tTG positive, 5 (12%) were positive with both the PA- and PG conjugates. whereas 3 (7%) were IgA-tTG positive. Compared with IgG-tTG the concordance was 93% for PA and 95% for PG, with a positive correlation between antibody levels (r=0.967 and r=0.975. p< ;0.0001). All but one CD child were found positive by combining IgG-tTG and IgA-tTG detection. Conclusions: The sensitivity of IgG-tTG detection with ELISA increased by protein A or protein G conjugates, whereas the specificity was reduced as compared with anti-IgG conjugate. The combined measurement of IgA-tTG and IgG-tTG still seems to be the optimal procedure when screening children for CD.
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