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We study the non-equilibrium structural dynamics of the incommensurate and nearly commensurate charge-density wave (CDW) phases in 1T- TaS 2 . Employing ultrafast low-energy electron diffraction with 1 ps temporal resolution, we investigate the ultrafast quench and recovery of the CDW-coupled periodic lattice distortion (PLD). Sequential structural relaxation processes are observed by tracking the intensities of main lattice as well as satellite diffraction peaks and the diffuse scattering background. Comparing distinct groups of diffraction peaks, we disentangle the ultrafast quench of the PLD amplitude from phonon-related reductions of the diffraction intensity. Fluence-dependent relaxation cycles reveal a long-lived partial suppression of the order parameter for up to 60 ps, far outlasting the initial amplitude recovery and electron-phonon scattering times. This delayed return to a quasi-thermal level is controlled by lattice thermalization and coincides with the population of zone-center acoustic modes, as evidenced by a structured diffuse background. The long-lived non-equilibrium order parameter suppression suggests hot populations of CDW-coupled lattice modes. Finally, a broadening of the superlattice peaks is observed at high fluences, pointing to a non-linear generation of phase fluctuations. [ABSTRACT FROM AUTHOR]

Background: Primary angiitis of the central nervous system (PACNS) is a rare but serious condition. A fraction of patients suffering from PACNS concurrently exhibit pronounced cerebral amyloid angiopathy (CAA) which is characterized by deposits of amyloid-β (Aβ) in and around the walls of small and medium-sized arteries of the brain. PACNS with CAA has been identified as a distinct disease entity, termed Aβ-related angiitis (ABRA). Evidence points to an immune reaction to vessel wall Aβ as the trigger of vasculitis. Objective: To investigate whether the inflammatory response to Aβ has (1) any effect on the status of immune activation in the brain parenchyma and (2) leads to clearance of Aβ from brain parenchyma. Methods: We studied immune activation and Aβ load by quantitative immunohistochemical analysis in brain parenchyma adjacent to affected vessels in 11 ABRA patients and 10 matched CAA controls. Results: ABRA patients showed significantly increased immune activation and decreased Aβ loads in the brain parenchyma adjacent to affected vessels. Conclusion: Our results are in line with the hypothesis of ABRA being the result of an excessive immune response to Aβ and show that this can lead to enhanced clearance of Aβ from the brain parenchyma by immune-mediated mechanisms. © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Aims/hypothesis: Exercise-induced hyperinsulinism (EIHI) is a hypoglycaemic disorder characterised by inappropriate insulin secretion following anaerobic exercise or pyruvate load. Activating promoter mutations in the MCT1 gene (also known as SCLA16A1), coding for monocarboxylate transporter 1 (MCT1), were shown to associate with EIHI. Recently, transgenic Mct1 expression in pancreatic beta cells was shown to introduce EIHI symptoms in mice. To date, MCT1 has not been demonstrated in insulin-producing cells from an EIHI patient. Methods: In vivo insulin secretion was studied during an exercise test before and after the resection of an insulinoma. The presence of MCT1 was analysed using immunohistochemistry followed by laser scanning microscopy, western blot analysis and real-time RT-PCR of MCT1. The presence of MCT1 protein was analysed in four additional insulinoma patients. Results: Clinical testing revealed massive insulin secretion induced by anaerobic exercise preoperatively, but not postoperatively. MCT1 protein was not detected in the patient's normal islets. In contrast, immunoreactivity was clearly observed in the insulinoma tissue. Western blot analysis and real-time RT-PCR showed a four- to fivefold increase in MCT1 in the insulinoma tissue of the EIHI patient compared with human pancreatic islets. MCT1 protein was detected in three of four additional insulinomas. Conclusions/interpretation: We show for the first time that an MCT1-expressing insulinoma was associated with EIHI and that MCT1 might be present in most insulinomas. Our data suggest that MCT1 expression in human insulin-producing cells can lead to EIHI and warrant further studies on the role of MCT1 in human insulinoma patients. [ABSTRACT FROM AUTHOR]

Copyright of Der Schmerz is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Der Internist is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The apolipoprotein E ε4 allele (APOE, gene; apoE, protein) is widely accepted as a risk factor for Alzheimer's disease (AD). Our previous studies found that APOEε4 promotes AD pathogenesis by fostering the early deposition of the amyloidogenic peptide Aβ in the aging brain. Recent reports suggest that polymorphisms in the upstream promoter region of APOE differentially affect the production of apoE and also may have an important influence on the probability of developing AD. In this study, we asked whether APOE promoter –491 (A/T) variants interact with APOE polymorphisms to modulate the degree of β-amyloid- and tau-related pathology in the medial temporal lobe of the non-demented elderly. Our results confirm that APOEε4 is associated with increased formation of senile plaques, cerebrovascular amyloid, and neurofibrillary tangles in the medial temporal lobe. We also found that homozygosity for A at position –491 of the APOE promoter (–491AA) correlates with increased Aβ17–24 and Aβ42 deposition in APOEε4-positive cases, but not in cases lacking the ε4 allele. In comparison, Aβ burden is significantly less in ε4 carriers with the –491AT and –491TT promoter allelotypes. There was no effect of –491 polymorphisms on Aβ40 deposition (which is relatively sparse in the non-demented elderly), on the number of activated microglia, or on the amount of neurofibrillary tangles. We conclude that the amyloidogenic effects of apoE4 are exacerbated by polymorphisms in the APOE promoter that enhance apoE production. [ABSTRACT FROM AUTHOR]

Presents a case of childhood onset mitochondrial myopathy and lactic acidosis caused by a stop mutation in the mitochondrial cytochrome c oxidase III gene. Key issues of interest; Analysis of pertinent topics and relevant issues; Implications on medical genetics.

The apolipoprotein Eℇ4 allele (ApoEℇ4) is associated with a selective increase in deposition of the 40-amino acid form of the β-amyloid peptide (Aβ40) in end-stage Alzheimer’s disease. To determine how apoE genotype affects the early events in β-amyloid pathogenesis, we analyzed the medial temporal lobes of 244 elderly persons who were not clinically demented using antibodies selective for the C termini of Aβ40 and Aβ42. We found that: (1) the number of both Aβ42- and Aβ40-positive senile plaques increase with age; (2) Aβ42 appears at younger ages, and in more amyloid deposits, than does Aβ40 in all ApoE groups; (3) when compared at similar ages, older persons with ApoEℇ4 are more likely to have Aβ42- and Aβ40-immunoreactive deposits than are persons without ApoEℇ4; (4) Aβ40-containing plaques arise at least a decade later than do Aβ42 plaques, and are seldom found in the medial temporal lobe of older persons lacking ApoEℇ4; and (5) in the absence of overt Alzheimer’s disease, cerebral amyloid angiopathy is rare in the elderly, but in our sample was significantly augmented in ApoEℇ4 homozygotes. We conclude that ApoEℇ4 hastens the onset of Aβ42 deposition in the senescent brain, which in turn fosters the earlier evolution of fibrillar, Aβ40-positive plaques, thereby increasing the risk of Alzheimer’s disease. [ABSTRACT FROM AUTHOR]

The accumulation of neurotoxic amyloid-β (Aβ) peptides within the brain represents a hallmark of Alzheimer's disease (AD). It is proposed to be partly due to reduced elimination of Aβ from the brain into the blood. Diverse mechanisms of Aβ clearance out of the brain have been suggested. As discussed here, several lines of evidence suggest a significant role of the MDR1-P-glycoprotein (ABCB1), which is a major component of the blood-brain barrier (BBB). [ABSTRACT FROM AUTHOR]

A forty-six year old female patient presented with a five months history of numbness in the right foot and right arm caused by a contrast enhancing lesion in the left occipital and parietal lobe. Three years ago a multiple myeloma (MM) (IgG, stage IIIA) had been diagnosed and treated with autologous stem cell transplantation and radiation.A stereotactic biopsy of the CNS lesion revealed an ill-defined demyelinating lesion with relative preservation of axons. Inflammatory infiltrates consisting of macrophages, plasma cells and lymphocytes were found accentuated around small vessels as well as diffusely distributed within the parenchyma. The plasma cells had pleomorphic nuclei and were proliferating when stained for the proliferation marker Ki-67. Polymerase chain reaction (PCR) analysis demonstrated monoclonality of the immunoglobulin heavy chain and the diagnosis of a CNS manifestation of multiple myeloma was made. Intraparenchymal CNS lesions are rare manifestations of multiple myeloma. The presentation of a CNS MM with extensive inflammatory demyelination is believed to be the first reported case. [ABSTRACT FROM AUTHOR]