100,312 research outputs found
Oxidative damage to lymphocyte DNA from AD patients
OBJECTIVE: Several studies show structural and functional alterations in peripheral cells in AD. The purpose of this study was to evaluate oxidative stress in AD lymphocytes.
BACKGROUND: The literature supports the role of reactive oxygen species in the pathogenesis of AD because several markers of oxidative damage have been detected in AD brain.
METHODS: 8-hydroxy-2'-deoxyguanosine (8OHdG), a marker of oxidative stress in DNA, was measured in lymphocytes of AD patients and healthy aged controls with high-pressure liquid chromatography with electrochemical detection, both at basal condition and after acute oxidative stress with hydrogen peroxide.
RESULTS: A significantly higher concentration of 8OHdG in lymphocytes occurred in AD patients compared with controls. In this latter group, 8OHdG increased progressively with age. After acute oxidative stress, levels of formed 8OHdG did not differ between AD patients and controls.
CONCLUSIONS: Our results support that AD is affected by oxidative stress, detectable not only in the brain but also in peripheral cells; oxidative mechanisms may contribute to the pathogenesis of AD. Additional studies in other neurodegenerative diseases are needed to evaluate these findings
Association between apolipoprotein E epsilon4 allele and apathy in probable Alzheimer's disease.
OBJECTIVE:
There have been inconclusive results to date on the association between the Apolipoprotein E (ApoE) genotype and neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD). We investigated whether ApoE epsilon4 allele is associated with NPS in probable AD.
METHOD:
Data for 197 subjects with probable AD were analysed. The Neuropsychiatric Inventory was used to evaluate the frequency and severity of NPS. Multiple logistic regression models were used to test the association between ApoE genotype and NPS in AD.
RESULTS:
The ApoE epsilon3/3 genotype was present in 52.3%, epsilon3/4 in 44.1%, and epsilon4/4 in 3.6% of patients. ApoE epsilon4 carriers showed a higher frequency of apathy than non-carriers. After multiple adjustments, the ApoE epsilon4 allele was significantly associated with apathy.
CONCLUSION:
Our results suggest a relationship between the ApoE epsilon4 allele and apathy in patients with AD
Association between the apolipoprotein e4 allele and apathy in probable Alzheimer's disease
Interaction of CTSD and A2M polymorphisms in the risk for Alzheimer's disease
The proteins cathepsin D, encoded by CTSD gene, and alpha2-macroglobulin, encoded by A2M gene, are involved in the biochemical pathway leading to deposition of beta-amyloid. In these proteins two amino acid polymorphisms (CTSD-Ala/Val C-->T and A2M-Ile/Val A-->G) have been associated with an increased risk for Alzheimer's disease (AD), but conflicting results have been reported. We studied the association and the mutual interactions of the CTSD-C/T and A2M-A/G polymorphisms with sporadic AD in 100 patients with late-onset AD and 136 healthy elderly subjects as controls. The CTSD-T allele and the CTSD-C/T genotype are significantly more frequent in AD than in controls. The odds ratio (OR) for CTSD-T subjects is 1.93 [95% confidence interval (CI)=1.01-3.72], and 2.07 (95% CI=1.01-4.21) after adjustment for age, sex and APOE epsilon4+ status, while no significant association was found for the A2M-A/G polymorphism. The coexistence of the CTSD-T with the A2M-G allele synergistically increased the OR for AD to 2.69 (95% CI=1.13-6.34) [2.82 (95% CI=1.12-7.17) after adjustment], and to 3.29 (95% CI=1.33-8.16) if estimated for the allelic combination. Our data suggest that the CTSD-T allele of the CTSD-C/T polymorphism is associated with an increased relative risk for late-onset AD and, more interestingly, the combination of CTSD-T with the A2M-G allele seems to increase this risk
Letter, [Author unclear] to Paulina T. Merritt
Handwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
Antioxidant profile and early outcome in stroke patients
BACKGROUND AND PURPOSE: Experimental studies provide evidence of an association between ischemic stroke and increased oxidative stress, but data in humans are still limited and controversial. The purpose of this study was to investigate the time course of plasma antioxidant changes in ischemic stroke patients.
METHODS: Plasma antioxidants, including water-soluble (vitamin C and uric acid) and lipid-soluble (vitamins A and E) compounds as well as antioxidant enzyme activities in plasma (superoxide dismutase [SOD] and glutathione peroxidase) and erythrocytes (SOD), were measured by high-performance liquid chromatography (antioxidant vitamins) and by spectrophotometry (antioxidant enzymes) in 38 subjects (25 men and 13 women aged 77.2+/-7.9 years) with acute ischemic stroke of recent onset (<24 hours) on admission, after 6 and 24 hours, and on days 3, 5, and 7. Antioxidant levels in patients on admission were compared with those of age- and sex-matched controls.
RESULTS: Mean antioxidant levels and activities in patients on admission were lower than those of controls and showed a gradual increase over time. Patients with the worst early outcome (death or functional decline) had higher vitamin A and uric acid plasma levels and lower vitamin C levels and erythrocyte SOD activity than those who remained functionally stable.
CONCLUSIONS: These results suggest that the majority of antioxidants are reduced immediately after an acute ischemic stroke, possibly as a consequence of increased oxidative stress. A specific antioxidant profile is associated with a poor early outcom
Handwritten biographical information on Paulina T. McClung Merritt
A handwritten biography of Paulina T. McClung Merritt by an unknown author, 1892.
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
IFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
Dispelling the Myths Behind First-author Citation Counts
We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Pelevin’s Trinity in the novel “t”: author – protagonist – reader
The article attempts to interpret Pelevin's artistic strategy in the novel "T" by exploring its subject organization and addressing the key problems of the author, the protagonist, and the reader as they are seen by the researcher. The article analyzes the peculiarities of constructing the narrative reality in the novel "T", and goes on to discuss Pelevin's philosophic models of the development of the humankind, and the emergence of his new anthropology
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