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Search Results: 1 - 10 of 494395 matches for " M. B. McBride "
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Arsenic and Lead Uptake by Vegetable Crops Grown on Historically Contaminated Orchard Soils
M. B. McBride
Applied and Environmental Soil Science , 2013, DOI: 10.1155/2013/283472
Abstract: Transfer of Pb and As into vegetables grown on orchard soils historically contaminated by Pb arsenate pesticides was measured in the greenhouse. Lettuce, carrots, green beans, and tomatoes were grown on soils containing a range of total Pb (16.5–915?mg/kg) and As (6.9–211?mg/kg) concentrations. The vegetables were acid-digested and analyzed for total Pb and As using ICP-mass spectrometry. Vegetable contamination was dependent on soil total Pb and As concentrations, pH, and vegetable species. Arsenic concentrations were the highest in lettuce and green beans, lower in carrots, and much lower in tomato fruit. Transfer of Pb into lettuce and beans was generally lower than that of As, and Pb and As were strongly excluded from tomato fruit. Soil metal concentrations as high as 400?mg/kg Pb and 100?mg/kg As produced vegetables with concentrations of Pb and As below the limits of international health standards. 1. Introduction Arsenic (As) and lead (Pb) have been used historically in pesticides (e.g., calcium arsenate, lead arsenate, and copper arsenate) applied to orchard crops such as apples and peaches, as well as to some other crops such as potatoes. Because Pb is quite immobile, and As is only very slowly leached through soils [1, 2], the cumulative contamination of orchard soils by lead and arsenate beginning in the late 1800s persists today [3]. As old orchard lands are converted from agricultural to residential uses, the potential hazard to human health may be increased from certain exposure pathways arising from gardening and direct contact with soil. The scale of this problem is largely based on estimates that millions of acres across North America have been contaminated by arsenic and lead pesticides. Virginia may have 100,000–300,000 acres of old orchard land [3], and other states with large acreages of impacted orchard land include Washington (188,000 acres), Wisconsin (50,000 acres) and New Jersey (up to 5% of the total agricultural acreage) [2]. The total area of historical soil contamination in New York state is uncertain, but apple production has occupied about 40–50,000 acres in recent decades, with a general long-term decline in orchard acreage and a simultaneous increase in yield. It seems likely, then, that the present apple crop acreage underestimates the total land area that may have been contaminated by As and Pb at some time in the past. The potential transfer of soil Pb and As into vegetable crops is a concern when garden soils are contaminated by these toxic metals. With growing concern about dietary exposure to these two toxic
Metabolic and Physiological Impact of Probiotics or Direct-Fed-Microbials on Poultry: A Brief Review of Current Knowledge
M. Chichlowski,J. Croom,B. W. McBride,G. B. Havenstein
International Journal of Poultry Science , 2007,
Abstract: The poultry industry is facing a ban on the use of antibiotic feed additives in many parts of the world. Consequently, there is a growing interest in finding viable alternatives for disease prevention and growth enhancing supplements. The effects of probiotics or direct fed microbials (DFM) on gut health and performance in poultry as well as other species are presented. The interactions between intestinal microbiota, the gut epithelium and the immune system are important in the competitive exclusion process. The mechanisms by which probiotics operate include spatial exclusion, micro-environmental alterations, production of antimicrobial substances and epithelial barrier integrity. The preponderance of research data in this field suggests the likelihood of a small but additive series of beneficial changes from an animal`s exposure to probiotics. Further investigations will be needed to fully characterize the effects and sustained outcomes of probiotic and DFM treatments in poultry.
The Effects of Direct-fed Microbial, Primalac , or Salinomycin Supplementation on Intestinal Lactate Isomers and Cecal Volatile Fatty Acid Concentrations in Broilers1
J. Croom,M. Chichlowski,M. Froetschel,B.W. McBride
International Journal of Poultry Science , 2009,
Abstract: Direct-Fed Microbials (DFM) are a putative alternative to the feeding of sub-therapeutic levels of antibiotics in the production of poultry and other livestock species. This study was designed to examine the effects of a commercial DFM (Primalac ), or salinomycin (SAL), a commonly used antibiotic and coccidiostat supplement, on fermentation patterns and lactate production in the cecum and the lower intestinal tract of broiler chickens. L-lactate and total lactate concentrations in the digesta fluid of the ileum decreased (P<0.01) with the DFM feeding in comparison to CON and SAL treatments while d-lactate concentration increased (P<0.04) in comparison to CON. Total cecal VFA concentration was lower (P<0.003) with DFM feeding and SAL than the CON. In the present study both dietary supplements, DFM and SAL, altered lactic acid and VFA concentrations in the cecum and intestines of experimental animals; however the full spectrum of mechanisms responsible for antibacterial properties and growth promotion associated with those changes remains to be elucidated.
Direct Fed Microbial, Primalac , Supplementation and Jejunal Glucose and Proline Transport in Broiler Chickens
M. Chichlowski,J. Croom,R. Qui,B.W. McBride
International Journal of Poultry Science , 2008,
Abstract: Direct fed microbials (DFM) are a putative alternative to the feeding of subtherapeutic levels of antibiotics in poultry production. Previous studies with a DFM, Primalac , have suggested that DFM may decrease ileal energy expenditures in broilers. These changes might be related to nutrient transport in the gastrointestinal (GI) tract. The current study examined the effects of supplementing broiler diets with DFM on ileal glucose and proline absorption and their relationships to GI energy expenditures. Twenty-four broiler chickens were fed a standard starter diet (CON) and CON + DFM, (PrimaLac 0.3% w/w) from hatch to 3 wk of age. On d 21, birds were euthanized, ileal tissue was dissected and glucose and proline uptake were estimated. In adjacent tissue, total O2 (TO2) and oubain (Na/K ATPase-sensitive) O2 consumption were estimated. Primalac had no effect (P>0.05) on ileal glucose and proline absorption transport rates as well as oubain sensitive and non-oubain sensitive oxygen consumption rates. Total passive transport of proline across the entire ileum was decreased by Primalac .
Cavitating Mesenteric Lymph Node Syndrome in Association with Coeliac Disease and Enteropathy Associated T-Cell Lymphoma: A Case Report and Review of the Literature
Olivia M. B. McBride,Richard J. E. Skipworth,Derek Leitch,Satheesh Yalamarthi
Case Reports in Medicine , 2010, DOI: 10.1155/2010/478269
Abstract: Cavitating mesenteric lymph node syndrome (CMLNS) is a rare and poorly understood complication of coeliac disease (CD), with only 37 cases reported in the literature. CD is an immune-mediated enteropathy, with alterations seen in the small bowel architecture on exposure to ingested gluten. Those who fail to respond to a strict gluten-free diet are termed to have refractory coeliac disease (RCD). This is associated with serious complications such as enteropathy-associated T-cell lymphoma (EATL). We present the case of a 71-year-old female investigated for weight loss and a palpable intraabdominal mass. Abdominal computed tomographic (CT) scan showed multiple necrotic mesenteric lymph nodes. At operation, multiple cavitating mesenteric lymph nodes, containing milky fluid, were found. An incidental EATL was found at the terminal ileum, which was resected. The patient subsequently tested positive for CD. This is the second case report to document an association between CMLNS and EATL. This paper highlights the varied presentation of CD. In this case, the diagnosis of CD was made retrospectively after the complications were dealt with. This paper is followed by a review of relevant literature.
Blazing a Trail: A Public Health Research Agenda in Genomics and Chronic Disease
Colleen M. McBride, PhD
Preventing Chronic Disease , 2005,
Abstract: Whether and when genomics will lead to public health benefit via reductions in chronic disease burden has provided fodder for debate (1,2). A point of agreement among both proponents and skeptics is that directing genomics research to achieve this end will require integration of knowledge across multiple disciplines and levels of analysis (i.e., biological, behavioral, social, and environmental) (3). Getting started on building these collaborations while the territory is new could temper the disciplinary hegemony that so often presents formidable barriers to transdisciplinary research (4). That said, when it comes to genomics, which has been the bastion of bench scientists and most recently epidemiologists, it may be especially challenging to attract the array of chronic disease researchers with expertise in health education, health psychology, health services delivery, and community-based intervention that will be critical to further this research agenda.
Emerging roles of mitochondria in the evolution, biogenesis, and function of peroxisomes
Abhishek Mohanty,Heidi M. McBride
Frontiers in Physiology , 2013, DOI: 10.3389/fphys.2013.00268
Abstract: In the last century peroxisomes were thought to have an endosymbiotic origin. Along with mitochondria and chloroplasts, peroxisomes primarily regulate their numbers through the growth and division of pre-existing organelles, and they house specific machinery for protein import. These features were considered unique to endosymbiotic organelles, prompting the idea that peroxisomes were key cellular elements that helped facilitate the evolution of multicellular organisms. The functional similarities to mitochondria within mammalian systems expanded these ideas, as both organelles scavenge peroxide and reactive oxygen species, both organelles oxidize fatty acids, and at least in higher eukaryotes, the biogenesis of both organelles is controlled by common nuclear transcription factors of the PPAR family. Over the last decade it has been demonstrated that the fission machinery of both organelles is also shared, and that both organelles act as critical signaling platforms for innate immunity and other pathways. Taken together it is clear that the mitochondria and peroxisomes are functionally coupled, regulating cellular metabolism and signaling through a number of common mechanisms. However, recent work has focused primarily on the role of the ER in the biogenesis of peroxisomes, potentially overshadowing the critical importance of the mitochondria as a functional partner. In this review, we explore the mechanisms of functional coupling of the peroxisomes to the mitochondria/ER networks, providing some new perspectives on the potential contribution of the mitochondria to peroxisomal biogenesis.
Novel Molecular Markers of Malignancy in Histologically Normal and Benign Breast
Aejaz Nasir,Dung-Tsa Chen,Mike Gruidl,Evita B. Henderson-Jackson,Chinnambally Venkataramu,Susan M. McCarthy,Heyoung L. McBride,Eleanor Harris,Nazanin Khakpour,Timothy J. Yeatman
Pathology Research International , 2011, DOI: 10.4061/2011/489064
Abstract: To detect the molecular changes of malignancy in histologically normal breast (HNB) tissues, we recently developed a novel 117-gene-malignancy-signature. Here we report validation of our leading malignancy-risk-genes, topoisomerase-2-alpha (TOP2A), minichromosome-maintenance-protein-2 (MCM2) and “budding-uninhibited-by-benzimidazoles-1-homolog-beta” (BUB1B) at the protein level. Using our 117-gene malignancy-signature, we classified 18 fresh-frozen HNB tissues from 18 adult female breast cancer patients into HNB-tissues with low-grade (HNB-LGMA; ) and high-grade molecular abnormality (HNB-HGMA; ). Archival sections of additional HNB tissues from these patients, and invasive ductal carcinoma (IDC) tissues from six other patients were immunostained for these biomarkers. TOP2A/MCM2 expression was assessed as staining index (%) and BUB1B expression as H-scores (0–300). Increasing TOP2A, MCM2, and BUB1B protein expression from HNB-LGMA to HNB-HGMA tissues to IDCs validated our microarray-based molecular classification of HNB tissues by immunohistochemistry. We also demonstrated an increasing expression of TOP2A protein on an independent test set of HNB/benign/reductionmammoplasties, atypical-ductal-hyperplasia with and without synchronous breast cancer, DCIS and IDC tissues using a custom tissue microarray (TMA). In conclusion, TOP2A, MCM2, and BUB1B proteins are potential molecular biomarkers of malignancy in histologically normal and benign breast tissues. Larger-scale clinical validation studies are needed to further evaluate the clinical utility of these molecular biomarkers. 1. Introduction Despite recent advances in biomarker discovery, no clinically proven biomarkers of increased breast cancer risk have been identified and validated in histologically normal breast. However, there is increasing evidence in the current literature for the presence of specific genetic abnormalities in histologically normal breast tissue in patients with and without breast cancer [1–10]. Such genetic abnormalities are often common to the tumor and their matched histologically normal breast tissues, suggesting their association with subsequent development of breast cancer in those patients. Whether such molecular abnormalities are the cause or the effect of the development of breast cancer is largely unknown. Also the degree of expression and microanatomical distribution of these molecular abnormalities in histologically normal/benign breast tissues is still poorly defined. In order to elucidate the molecular changes of malignancy in HNB tissues, we used the Affymetrix
INTEGRAL and XMM-Newton observations of IGR J16418-4532: evidence of accretion regime transitions in a supergiant fast X-ray transient
S. P. Drave,A. J. Bird,L. Sidoli,V. Sguera,V. A. McBride,A. B. Hill,A. Bazzano,M. E. Goossens
Physics , 2013, DOI: 10.1093/mnras/stt754
Abstract: We report on combined INTEGRAL and XMM-Newton observations of the supergiant fast X-ray transient IGR J16418-4532. The observations targeted the X-ray eclipse region of IGR J16418-4532s orbit with continuous INTEGRAL observations across ~25% of orbital phase and two quasi-simultaneous XMM-Newton observations of length 20ks and 14ks, occurring during and just after the eclipse respectively. An enhanced INTEGRAL emission history is provided with 19 previously unreported outbursts identified in the archival 18-60 keV data set. The XMM-Newton eclipse observation showed prominent Fe-emission and a flux of 2.8*10^-13 erg cm^-2 s^-1 (0.5 - 10 keV). Through the comparison of the detected eclipse and post eclipse flux, the supergiant mass loss rate through the stellar wind was determined as \dot{M}_{w} = 2.3-3.8*10^-7 M_{\odot} yr^-1. The post eclipse XMM-Newton observation showed a dynamic flux evolution with signatures of the X-ray pulsation, a period of flaring activity, structured nH variations and the first ever detection of an X-ray intensity dip, or 'off-state', in a pulsating supergiant fast X-ray transient. Consideration is given to the origin of the X-ray dip and we conclude that the most applicable of the current theories of X-ray dip generation is that of a transition between Compton cooling dominated and radiative cooling dominated subsonic accretion regimes within the 'quasi-spherical' model of wind accretion. Under this interpretation, which requires additional confirmation, the neutron star in IGR J16418-4532 possesses a magnetic field of ~10^14 G, providing tentative observational evidence of a highly magnetised neutron star in a supergiant fast X-ray transient for the first time. The implications of these results on the nature of IGR J16418-4532 itself and the wider SFXT class are discussed.
Discovering a 5.72 Day Period in the Supergiant Fast X-ray Transient AX J1845.0-0433
M. E. Goossens,A. J. Bird,S. P. Drave,A. Bazzano,A. B. Hill,V. A. McBride,V. Sguera,L. Sidoli
Physics , 2013, DOI: 10.1093/mnras/stt1166
Abstract: Temporal analysis of INTEGRAL/IBIS data has revealed a 5.7195\pm0.0007 day periodicity in the supergiant fast X-ray transient (SFXT) source AX J1845.0-0433, which we interpret as the orbital period of the system. The new-found knowledge of the orbital period is utilised to investigate the geometry of the system by means of estimating an upper limit for the size of the supergiant (<27 R_{\sun}) as well as the eccentricity of the orbit (\epsilon<0.37).
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