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121.
Cassandra L.A. Hawco Estelle Marchal Md. Imam Uddin Alexander E.G. Baker Dale P. Corkery Graham Dellaire Alison Thompson 《Bioorganic & medicinal chemistry》2013,21(19):5995-6002
To generate the first series of prodigiosene conjugates, the tripyrrolic skeleton was appended to estrone, tamoxifen and porphyrin frameworks by way of ester linkers and various hydrocarbon chain lengths. The ability of the conjugates to inhibit various types of cancer cells was evaluated in vitro. The porphyrin conjugates did not exhibit significant activity. The estrone conjugates exhibited modest activity, for the most part. However, significantly greater growth inhibition activity against certain breast, colon, lung, leukemia, melanoma and prostate cell lines was noted. This unusual effect for this first generation model class of compound warrants further investigation and comparison to cases where estrogens are linked to prodigiosenes via connection points that do not feature in estrogen receptor binding. The 4-hydroxytamoxifen conjugates exhibit nanomolar range activity against the MCF-7 breast cancer cell line, paving the way to expand the scope and connectivity of prodigiosene–tamoxifen conjugates. 相似文献
122.
Thomas T.Y. Wang Alison J. Edwards Beverly A. Clevidence 《The Journal of nutritional biochemistry》2013,24(8):1538-1546
The mechanisms as well the genetics underlying the bioavailability and metabolism of carotenoids in humans remain unclear. To begin to address these questions, we used cluster analysis to examine individual temporal responses of plasma carotenoids from a controlled-diet study of subjects who consumed carotenoid-rich beverages. Treatments, given daily for 3 weeks, were watermelon juice at two levels (20-mg lycopene, 2.5-mg β-carotene, n=23 and 40-mg lycopene, 5-mg β-carotene, n=12) and tomato juice (18-mg lycopene, 0.6-mg β-carotene, n=10). Cluster analysis revealed distinct groups of subjects differing in the temporal response of plasma carotenoids and provided the basis for classifying subjects as strong responders or weak responders for β-carotene, lycopene, phytoene and phytofluene. Individuals who were strong or weak responders for one carotenoid were not necessarily strong or weak responders for another carotenoid. Furthermore, individual responsiveness was associated with genetic variants of the carotenoid metabolizing enzyme β-carotene 15,15'-monooxygenase 1. These results support the concept that individuals absorb or metabolize carotenoids differently across time and suggest that bioavailability of carotenoids may involve specific genetic variants of β-carotene 15,15'-monooxygenase 1. 相似文献
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125.
Ross S. Osgood Brad L. Upham Thomas Hill III Katherine L. Helms Kalpana Velmurugan Pavel Babica Alison K. Bauer 《PloS one》2013,8(6)
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental and occupational toxicants, which are a major human health concern in the U.S. and abroad. Previous research has focused on the genotoxic events caused by high molecular weight PAHs, but not on non-genotoxic events elicited by low molecular weight PAHs. We used an isomeric pair of low molecular weight PAHs, namely 1-Methylanthracene (1-MeA) and 2-Methylanthracene (2-MeA), in which only 1-MeA possessed a bay-like region, and hypothesized that 1-MeA, but not 2-MeA, would affect non-genotoxic endpoints relevant to tumor promotion in murine C10 lung cells, a non-tumorigenic type II alveolar pneumocyte and progenitor cell type of lung adenocarcinoma. The non-genotoxic endpoints assessed were dysregulation of gap junction intercellular communication function and changes in the major pulmonary connexin protein, connexin 43, using fluorescent redistribution and immunoblots, activation of mitogen activated protein kinases (MAPK) using phosphospecific MAPK antibodies for immunoblots, and induction of inflammatory genes using quantitative RT-PCR. 2-MeA had no effect on any of the endpoints, but 1-MeA dysregulated gap junctional communication in a dose and time dependent manner, reduced connexin 43 protein expression, and altered membrane localization. 1-MeA also activated ERK1/2 and p38 MAP kinases. Inflammatory genes, such as cyclooxygenase 2, and chemokine ligand 2 (macrophage chemoattractant 2), were also upregulated in response to 1-MeA only. These results indicate a possible structure-activity relationship of these low molecular weight PAHs relevant to non-genotoxic endpoints of the promoting aspects of cancer. Therefore, our novel findings may improve the ability to predict outcomes for future studies with additional toxicants and mixtures, identify novel targets for biomarkers and chemotherapeutics, and have possible implications for future risk assessment for these PAHs. 相似文献
126.
Caoimhe Cawley Alison Wringe Raphael Isingo Baltazar Mtenga Benjamin Clark Milly Marston Jim Todd Mark Urassa Basia Zaba 《PloS one》2013,8(4)
Background
HIV counselling and testing (HCT) services can play an important role in HIV prevention by encouraging safe sexual behaviours and linking HIV-infected clients to antiretroviral therapy (ART). However, regular repeat testing by high-risk HIV-negative individuals is important for timely initiation of ART as part of the ‘treatment as prevention’ approach.Aim
To investigate HCT use during a round of HIV serological surveillance in northwest Tanzania in 2010, and to explore rates of repeat testing between 2003 and 2010.Methods
HCT services were provided during the fourth, fifth and sixth rounds of serological surveillance in 2003–2004 (Sero-4), 2006–2007 (Sero-5) and 2010 (Sero-6). HCT services have also been available at a government-run health centre and at other clinics in the study area since 2005. Questionnaires administered during sero-surveys collected information on socio-demographic characteristics, sexual behaviour and reported previous use of HCT services.Results
The proportion of participants using HCT increased from 9.4% at Sero-4 to 16.6% at Sero-5 and 25.5% at Sero-6. Among participants attending all three sero-survey rounds (n = 2,010), the proportions using HCT twice or more were low, with 11.1% using the HCT service offered at sero-surveys twice or more, and 25.3% having tested twice or more if reported use of HCT outside of sero-surveys was taken into account. In multivariable analyses, individuals testing HIV-positive were less likely to repeat test than individuals testing HIV-negative (aOR 0.17, 95% CI 0.006–0.52).Discussion/Conclusions
Although HCT service use increased over time, it was disappointing that the proportions ever testing and ever repeat-testing were not even larger, considering the increasing availability of HCT and ART in the study area. There was some evidence that HIV-negative people with higher risk sexual behaviours were most likely to repeat test, which was encouraging in terms of the potential to pick-up those at greatest risk of HIV-infection. 相似文献127.
Alyssa D. Flora Louise D. Teel Mark A. Smith James F. Sinclair Angela R. Melton-Celsa Alison D. O’Brien 《PloS one》2013,8(7)
Ricin is a potent toxin found in the beans of Ricinus communis and is often lethal for animals and humans when aerosolized or injected and causes significant morbidity and occasional death when ingested. Ricin has been proposed as a bioweapon because of its lethal properties, environmental stability, and accessibility. In oral intoxication, the process by which the toxin transits across intestinal mucosa is not completely understood. To address this question, we assessed the impact of ricin on the gastrointestinal tract and organs of mice after dissemination of toxin from the gut. We first showed that ricin adhered in a specific pattern to human small bowel intestinal sections, the site within the mouse gut in which a variable degree of damage has been reported by others. We then monitored the movement of ricin across polarized human HCT-8 intestinal monolayers grown in transwell inserts and in HCT-8 cell organoids. We observed that, in both systems, ricin trafficked through the cells without apparent damage until 24 hours post intoxication. We delivered a lethal dose of purified fluorescently-labeled ricin to mice by oral gavage and followed transit of the toxin from the gastrointestinal tracts to the internal organs by in vivo imaging of whole animals over time and ex vivo imaging of organs at various time points. In addition, we harvested organs from unlabeled ricin-gavaged mice and assessed them for the presence of ricin and for histological damage. Finally, we compared serum chemistry values from buffer-treated versus ricin-intoxicated animals. We conclude that ricin transverses human intestinal cells and mouse intestinal cells in situ prior to any indication of enterocyte damage and that ricin rapidly reaches the kidneys of intoxicated mice. We also propose that mice intoxicated orally with ricin likely die from distributive shock. 相似文献
128.
Elizabeth Dao Jennifer C. Davis Devika Sharma Alison Chan Lindsay S. Nagamatsu Teresa Liu-Ambrose 《PloS one》2013,8(1)
Objectives
To investigate the independent contribution of change in sub-total body fat and lean mass to cognitive performance, specifically the executive processes of selective attention and conflict resolution, in community-dwelling older women.Methods
This secondary analysis included 114 women aged 65 to 75 years old. Participants were randomly allocated to once-weekly resistance training, twice-weekly resistance training, or twice-weekly balance and tone training. The primary outcome measure was the executive processes of selective attention and conflict resolution as assessed by the Stroop Test. Sub-total body fat and lean mass were measured by dual-energy x-ray absorptiometry (DXA) to determine the independent association of change in both sub-total body fat and sub-total body lean mass with Stroop Test performance at trial completion.Results
A multiple linear regression model showed reductions in sub-total body fat mass to be independently associated with better performance on the Stroop Test at trial completion after accounting for baseline Stroop performance, age, baseline global cognitive state, baseline number of comorbidities, baseline depression, and experimental group. The total variance explained was 39.5%; change in sub-total body fat mass explained 3.9% of the variance. Change in sub-total body lean mass was not independently associated with Stroop Test performance (P>0.05).Conclusion
Our findings suggest that reductions in sub-total body fat mass – not sub-total lean mass – is associated with better performance of selective attention and conflict resolution. 相似文献129.
Background
Werner syndrome (WS) is an autosomal recessive genetic instability and progeroid (‘premature aging’) syndrome which is associated with an elevated risk of cancer.Objectives
Our study objectives were to characterize the spectrum of neoplasia in WS using a well-documented study population, and to estimate the type-specific risk of neoplasia in WS relative to the general population.Methods
We obtained case reports of neoplasms in WS patients through examining previous case series and reviews of WS, as well as through database searching in PubMed, Google Scholar, and J-EAST, a search engine for articles from Japan. We defined the spectrum (types and sites) of neoplasia in WS using all case reports, and were able to determine neoplasm type-specific risk in Japan WS patients by calculating standardized incidence and proportionate incidence ratios (SIR and SPIR, respectively) relative to Osaka Japan prefecture incidence rates.Results
We used a newly assembled study population of 189 WS patients with 248 neoplasms to define the spectrum of neoplasia in WS. The most frequent neoplasms in WS patients, representing 2/3 of all reports, were thyroid neoplasms, malignant melanoma, meningioma, soft tissue sarcomas, leukemia and pre-leukemic conditions of the bone marrow, and primary bone neoplasms. Cancer risk defined by SIRs was significantly elevated in Japan-resident WS patients for the six most frequent neoplasms except leukemia, ranging from 53.5-fold for melanoma of the skin (95% CI: 24.5, 101.6) to 8.9 (95% CI: 4.9, 15.0) for thyroid neoplasms. Cancer risk as defined by SPIR was also significantly elevated for the most common malignancies except leukemia.Conclusions
WS confers a strong predisposition to several specific types of neoplasia. These results serve as a guide for WS clinical care, and for additional analyses to define the mechanistic basis for cancer in WS and the general population. 相似文献130.
Rachel B. Slayton George Turabelidze Sarah D. Bennett Colin A. Schwensohn Anna Q. Yaffee Faisal Khan Cindy Butler Eija Trees Tracy L. Ayers Marjorie L. Davis Alison S. Laufer Stephen Gladbach Ian Williams Laura B. Gieraltowski 《PloS one》2013,8(2)