Amyloid : the international journal of experimental and clinical investigation : the official journal of the International Society of Amyloidosis
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The standardization and clinical validation of the measurement of beta-amyloid(1-42) (Abeta42) in cerebrospinal fluid (CSF), plasma and urine is described using a commercially available sandwich-type ELISA with 21F12 and 3D6 as monoclonal antibodies. The INNOTEST beta-amyloid(1-42) allows the specific and reliable measurement of(1-42) amyloid peptides in CSF and plasma. The Abeta42 concentrations in serum and urine were below the detection limit. ⋯ No correlation was found in AD patients between CSF and plasma concentrations of Abeta42 or between CSF Abeta42 levels and blood-brain-barrier function. The quantitative outcome of the test is in part dependent on confounding factors such as tube type, freeze/thaw cycles, temperature of incubation, standard preparation protocol, and antibody selection. Notwithstanding these aspects, it emerged that Abeta42 is a useful biochemical marker for the diagnosis of AD patients, but there is a need for an international Abeta standard, a universally accepted protocol for CSF preparation, and a thorough evaluation of assay performance in function of the boundary conditions.
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The gene frequency of the transthyretin (TTR) mutation (Val122Ile) was studied in African and African-American populations. The African populations analyzed included the Zulu and Xhosa of South Africa, and Yorubas from the city of Ibadan, Nigeria. ⋯ The Val122Ile TTR mutation was identified in 1 of 55 Zulu, 0 of 34 Xhosa, 0 of 9 Nigerian subjects, 5 of 51 Veteran patients, and 3 of 103 newborns. Assuming the 2.91% prevalence in newborns to be the norm, there is a significant increased prevalence in the VA patient population.
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Case Reports
A novel variant of transthyretin (Glu89Lys) associated with familial amyloidotic polyneuropathy.
We detected a point mutation in the transthyretin (TTR) gene associated with familial amyloidotic polyneuropathy (FAP) in a 57-year old male presenting with sensorimotor polyneuropathy, severe autonomic dysfunction and cardiomyopathy using a non-isotopic RNase cleavage assay (NIRCA). NIRCA suggested that the mutation site was near either amino acid position 58 of mature TTR or the 3' end of exon 3. ⋯ The site of this mutation is near the 3' end of exon 3, consistent with the result of NIRCA. This mutation was also confirmed by polymerase chain reaction-induced mutation restriction analysis (PCR-IMRA).