314 research outputs found
Intepirdine as Adjunctive Therapy to Donepezil for Mild-To-Moderate Alzheimerβs Disease: A Randomized, Placebo-Controlled, Phase 3 Clinical Trial (Mindset)
Introduction: A previous phase 2b study supported the use of the 5-HT6 receptor antagonist intepirdine as adjunctive therapy to donepezil for Alzheimer\u27s disease (AD) dementia. A phase 3 study, MINDSET, was performed to test this hypothesis. Methods: MINDSET was a global, double-blind, randomized, placebo-controlled trial in 1315 mild-to-moderate AD dementia patients on stable donepezil. Patients received 35 mg/day intepirdine or placebo for 24 weeks. The co-primary endpoints were change from baseline to week 24 on the Alzheimer\u27s Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) and Alzheimer\u27s Disease Cooperative Study-Activities of Daily Living (ADCS-ADL). Results: There were no statistically significant differences between intepirdine and placebo groups (adjusted mean [95% confidence interval]) on the co-primary endpoints ADAS-Cog (β0.36 [β0.95, 0.22], P = 0.2249) and ADCS-ADL (β0.09 [β0.90, 0.72], P = 0.8260). Intepirdine demonstrated a favorable safety profile similar to placebo. Discussion: Intepirdine as adjunctive therapy to donepezil did not produce statistical improvement over placebo on cognition or activities of daily living in mild-to-moderate AD dementia patients
Down-regulation of IFN-gamma-producing CD56+ T cells after combined low-dose cyclosporine/prednisone treatment in patients with Behcet's uveitis
PURPOSE: To investigate the effects of combined low-dose cyclosporine and prednisone (Cs/Pd) treatment on circulating CD56+ T cells in patients with Behcet's uveitis. METHODS: Ten patients with Behcet's uveitis and 10 healthy control subjects were prospectively recruited. The patients were treated with Cs/Pd for 2 months. Phenotypic and functional changes in circulating CD56+ T cells were assayed before and after treatment. CD56+ T-cell subsets were determined by flow cytometric analysis with monoclonal antibodies for CD3, CD4, CD8, CD56, pan gammadelta TCR, and Valpha24. The absolute numbers of cells in the lymphocyte subsets were calculated. Cytokine (IFN-gamma, IL-4, and IL-10) expressions were measured by ELISA and by intracellular cytokine staining. RESULTS: The proportions of CD56+ T cells, specifically CD8highCD56+ and CD56+gammadelta T-cell subsets, were significantly higher in active Behcet's uveitis but normalized after treatment, whereas the total T-lymphocyte count and the absolute numbers of CD56- T cells were unaffected by treatment. The levels of IFN-gamma and IL-4 were elevated in aqueous humor and serum in Behcet's uveitis (P < 0.001), whereas IL-10 was not detected. After treatment, serum IL-4 levels markedly increased (P < 0.001), and IFN-gamma production by circulating CD56+ T cells was then suppressed. IL-4 and -10 production by CD56+ T cells was increased by treatment, but in contrast, minimal changes were found in CD56- T cells. CONCLUSIONS: The results imply that Cs/Pd treatment for Behcet's uveitis selectively affects the population of and the cytokine expression in CD56+ T cells, but without significant changes in CD56- T cells, and that IFN-gamma-producing CD56+ T cells are the central pathogenic immune cells in Behcet's uveitis
K-Ras4A splice variant is widely expressed in cancer and uses a hybrid membrane-targeting motif
The KRAS oncogene is mutated more frequently in human cancer than any other. The KRAS transcript is alternatively spliced to give rise to two products, K-Ras4A and K-Ras4B, both of which are oncogenic when KRAS is mutated. We detected significant amounts of each transcript in human tumor cells and colorectal carcinomas. We found that K-Ras4A is targeted to the plasma membrane by dual targeting motifs distinct from those of K-Ras4B. Because interfering with membrane association of Ras proteins remains one of the most attractive approaches to anti-Ras therapy, efforts in this direction will have to disrupt both the K-Ras4A and the K-Ras4B membrane-targeting pathways
Malaria knowledge and agricultural practices that promote mosquito breeding in two rural farming communities in Oyo State, Nigeria
<p>Abstract</p> <p>Background</p> <p>Agricultural practices such as the use of irrigation during rice cultivation, the use of ponds for fish farming and the storage of water in tanks for livestock provide suitable breeding grounds for anthropophylic mosquitoes. The most common anthropophylic mosquito in Nigeria which causes much of the morbidity and mortality associated with malaria is the anopheles mosquito. Farmers are therefore at high risk of malaria - a disease which seriously impacts on agricultural productivity. Unfortunately information relating to agricultural practices and farmers' behavioural antecedent factors that could assist malaria programmers plan and implement interventions to reduce risk of infections among farmers is scanty. Farmers' knowledge about malaria and agricultural practices which favour the breeding of mosquitoes in Fashola and Soku, two rural farming communities in Oyo State were therefore assessed in two rural farming communities in Oyo State.</p> <p>Methods</p> <p>This descriptive cross-sectional study involved the collection of data through the use of eight Focus Group Discussions (FGDs) and the interview of 403 randomly selected farmers using semi-structured questionnaires. These sets of information were supplemented with observations of agricultural practices made in 40 randomly selected farms. The FGD data were recorded on audio-tapes, transcribed and subjected to content analysis while the quantitative data were analyzed using descriptive and inferential statistics.</p> <p>Results</p> <p>Most respondents in the two communities had low level of knowledge of malaria causation as only 12.4% stated that mosquito bite could transmit the disease. Less than half (46.7%) correctly mentioned the signs and symptoms of malaria as high body temperature, body pains, headache, body weakness and cold/fever. The reported main methods for preventing mosquito bites in the farming communities included removal of heaps of cassava tuber peelings (62.3%), bush burning/clearing (54.6%) and clearing of ditches (33.7%). The dumping of cassava tuber peelings which allows the collection of pools of water in the farms storage of peeled cassava tubers soaked in water in uncovered plastic containers, digging of trenches, irrigation of farms and the presence of fish ponds were the observed major agricultural practices that favoured mosquito breeding on the farms. A significant association was observed between respondents' knowledge about malaria and agricultural practices which promote mosquito breeding. Respondents' wealth quintile level was also seen to be associated with respondents' knowledge about malaria and agricultural practices which promote mosquito breeding.</p> <p>Conclusion</p> <p>Farmers' knowledge of malaria causation and signs and symptoms was low, while agricultural practices which favour mosquito breeding in the farming communities were common. There is an urgent need to engage farmers in meaningful dialogue on malaria reduction initiatives including the modification of agricultural practices which favour mosquito breeding. Multiple intervention strategies are needed to tackle the factors related to malaria prevalence and mosquito abundance in the communities.</p
Requirements for Efficient Proteolytic Cleavage of Prelamin A by ZMPSTE24
The proteolytic maturation of the nuclear protein lamin A by the zinc metalloprotease ZMPSTE24 is critical for human health. The lamin A precursor, prelamin A, undergoes a multi-step maturation process that includes CAAX processing (farnesylation, proteolysis and carboxylmethylation of the C-terminal CAAX motif), followed by ZMPSTE24-mediated cleavage of the last 15 amino acids, including the modified C-terminus. Failure to cleave the prelamin A "tail", due to mutations in either prelamin A or ZMPSTE24, results in a permanently prenylated form of prelamin A that underlies the premature aging disease Hutchinson-Gilford Progeria Syndrome (HGPS) and related progeroid disorders.Here we have investigated the features of the prelamin A substrate that are required for efficient cleavage by ZMPSTE24. We find that the C-terminal 41 amino acids of prelamin A contain sufficient context to allow cleavage of the tail by ZMPSTE24. We have identified several mutations in amino acids immediately surrounding the cleavage site (between Y646 and L647) that interfere with efficient cleavage of the prelamin A tail; these mutations include R644C, L648A and N650A, in addition to the previously reported L647R. Our data suggests that 9 of the 15 residues within the cleaved tail that lie immediately upstream of the CAAX motif are not critical for ZMPSTE24-mediated cleavage, as they can be replaced by the 9 amino acid HA epitope. However, duplication of the same 9 amino acids (to increase the distance between the prenyl group and the cleavage site) impairs the ability of ZMPSTE24 to cleave prelamin A.Our data reveals amino acid preferences flanking the ZMPSTE24 cleavage site of prelamin A and suggests that spacing from the farnesyl-cysteine to the cleavage site is important for optimal ZMPSTE24 cleavage. These studies begin to elucidate the substrate requirements of an enzyme activity critical to human health and longevity
The transcription factor 7-like 2 (TCF7L2) polymorphism may be associated with focal arteriolar narrowing in Caucasians with hypertension or without diabetes: the ARIC Study
<p>Abstract</p> <p>Background</p> <p>Transcription factor 7-like 2 (<it>TCF7L2</it>) has emerged as a consistently replicated susceptibility gene for type 2 diabetes, however, whether the <it>TCF7L2 </it>gene also has similar effects on the retinal microvasculature is less clear. We therefore aimed to investigate the association between the transcription factor 7-like 2 (<it>TCF7L2</it>) rs7903146 polymorphism and retinal microvascular phenotypes in the Atherosclerosis Risk in Communities (ARIC) Study (1993-1995).</p> <p>Methods</p> <p>This was a population-based, cross-sectional study of 10,320 middle-aged African American (n = 2,199) and Caucasian (n = 8,121) men and women selected from four United States communities to examine the association between <it>TCF7L2 </it>rs7903146 polymorphism and retinal microvascular signs (retinopathy, focal arteriolar narrowing, arteriovenous nicking, arteriolar and venular calibers). Photographs on one randomly selected eye were graded for presence of retinal microvascular signs and used to measure retinal vessel calibres.</p> <p>Results</p> <p>After adjusting for age, sex, study center, mean arterial blood pressure, total serum cholesterol, triglycerides, and other covariates, few associations of <it>TCF7L2 </it>rs7903146 and retinal microvascular signs were noted. <it>TCF7L2 </it>rs7903146 T risk allele was significantly associated with focal arteriolar narrowing in Caucasians with hypertension [odds ratio (OR)<sub>CT vs. CC </sub>(95% CI) = 1.25 (1.09-1.44); OR<sub>TT vs. CC </sub>= 1.56 (1.18-2.06); <it>P </it>= 0.002] and in Caucasians without diabetes [OR <sub>CT vs. CC </sub>= 1.18 (1.06-1.32); OR <sub>TT vs. CC </sub>= 1.40 (1.12, 1.75); <it>P </it>= 0.003]. No significant association of the <it>TCF7L2 </it>rs7903146 polymorphism and retinal vascular signs was noted among African American individuals.</p> <p>Conclusions</p> <p><it>TCF7L2 </it>rs7903146 is not consistently associated with retinal microvascular signs. However, we report an association between the <it>TCF7L2 </it>rs7903146 polymorphism and focal arteriolar narrowing in Caucasians with hypertension or without diabetes. Further research in other large, population-based studies is needed to replicate these findings.</p
Non-Small Cell Lung Carcinoma Cell Motility, Rac Activation and Metastatic Dissemination Are Mediated by Protein Kinase C Epsilon
Background: Protein kinase C (PKC) e, a key signaling transducer implicated in mitogenesis, survival, and cancer progression, is overexpressed in human primary non-small cell lung cancer (NSCLC). The role of PKCe in lung cancer metastasis has not yet been established. Principal Findings: Here we show that RNAi-mediated knockdown of PKCe in H358, H1299, H322, and A549 NSCLC impairs activation of the small GTPase Rac1 in response to phorbol 12-myristate 13-acetate (PMA), serum, or epidermal growth factor (EGF). PKCe depletion markedly impaired the ability of NSCLC cells to form membrane ruffles and migrate. Similar results were observed by pharmacological inhibition of PKCe with eV1-2, a specific PKCe inhibitor. PKCe was also required for invasiveness of NSCLC cells and modulated the secretion of extracellular matrix proteases and protease inhibitors. Finally, we found that PKCe-depleted NSCLC cells fail to disseminate to lungs in a mouse model of metastasis. Conclusions: Our results implicate PKCe as a key mediator of Rac signaling and motility of lung cancer cells, highlighting its potential as a therapeutic target
Evolutionary and Transmission Dynamics of Reassortant H5N1 Influenza Virus in Indonesia
H5N1 highly pathogenic avian influenza (HPAI) viruses have seriously affected the Asian poultry industry since their recurrence in 2003. The viruses pose a threat of emergence of a global pandemic influenza through point mutation or reassortment leading to a strain that can effectively transmit among humans. In this study, we present phylogenetic evidences for the interlineage reassortment among H5N1 HPAI viruses isolated from humans, cats, and birds in Indonesia, and identify the potential genetic parents of the reassorted genome segments. Parsimony analyses of viral phylogeography suggest that the reassortant viruses may have originated from greater Jakarta and surroundings, and subsequently spread to other regions in the West Java province. In addition, Bayesian methods were used to elucidate the genetic diversity dynamics of the reassortant strain and one of its genetic parents, which revealed a more rapid initial growth of genetic diversity in the reassortant viruses relative to their genetic parent. These results demonstrate that interlineage exchange of genetic information may play a pivotal role in determining viral genetic diversity in a focal population. Moreover, our study also revealed significantly stronger diversifying selection on the M1 and PB2 genes in the lineages preceding and subsequent to the emergence of the reassortant viruses, respectively. We discuss how the corresponding mutations might drive the adaptation and onward transmission of the newly formed reassortant viruses
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