28,969 research outputs found

    Farm-Level Impacts of Banning Growth- Promoting Antibiotic Use in U.S. Pig Grower/Finisher Operations

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    Antibiotics have been used by pig producers for several decades, and are now used routinely. This study documents the current productivity and economic impacts of the use of antibiotics for growth promotion (AGP) by pig grower/finishers at the farm level. We evaluate the impacts of an AGP ban, and use of AGP by all pig grower/finishers for 61S90 days (a more production-efficient level), using data from the National Animal Health Monitoring System Swine 2000 Survey. Findings indicate that pig productivity improves with AGP. Relative to current use, an AGP ban would decrease producer profits by 1,400per1,020headbarn,andprofitswouldincreaseby1,400 per 1,020-head barn, and profits would increase by 1,992 for each grower/finisher barn when AGP is fed for 61 to 90 days. There is increasing concern about the use of antibiotics in animal production, partly because of the selection for antibiotic resistance. Thus, a careful examination of the value of AGP in pork production is warranted.antibiotics, antimicrobial resistance, growth promotion, pigs, production, Agricultural and Food Policy, Health Economics and Policy, Livestock Production/Industries,

    Functional protection by acute phase proteins alpha(1)-acid glycoprotein and alpha(1)-antitrypsin against ischemia/reperfusion injury by preventing apoptosis and inflammation.

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    BACKGROUND: Ischemia followed by reperfusion (I/R) causes apoptosis, inflammation, and tissue damage leading to organ malfunction. Ischemic preconditioning can protect against such injury. This study investigates the contribution of the acute phase proteins alpha(1)-acid glycoprotein (AGP) and alpha(1)-antitrypsin (AAT) to the protective effect of ischemic preconditioning in the kidney. METHODS AND RESULTS: Exogenous AGP and AAT inhibited apoptosis and inflammation after 45 minutes of renal I/R in a murine model. AGP and AAT administered at reperfusion prevented apoptosis at 2 hours and 24 hours, as evaluated by the presence of internucleosomal DNA cleavage, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling, and the determination of renal caspase-1- and caspase-3-like activity. AGP and AAT exerted anti-inflammatory effects, as reflected by reduced renal tumor necrosis factor-alpha expression and neutrophil influx after 24 hours. In general, these agents improved renal function. Similar effects were observed when AGP and AAT were administered 2 hours after reperfusion but to a lesser extent and without functional improvement. Moreover, I/R elicited an acute phase response, as reflected by elevated serum AGP and serum amyloid P (SAP) levels after 24 hours, and increased hepatic acute phase protein mRNA levels after 18 hours of renal reperfusion. CONCLUSIONS: We propose that the antiapoptotic and anti-inflammatory effects of AGP and AAT contribute to the delayed type of protection associated with ischemic preconditioning and other insults. This mechanism is potentially involved in the course of many clinical conditions associated with I/R injury. Moreover, exogenous administration of these proteins may provide new therapeutic means of treatmen

    PRODUCER INCENTIVES FOR ANTIBIOTIC USE IN U.S. PORK PRODUCTION

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    Antibiotics have been used in animal production for several decades. Antibiotics are used routinely now in pork production (NAHMS 2002). There is increasing concern about the use of antibiotics in animal production. There is no hard evidence supporting the link of antibiotic use in animals to observations of antibiotic resistance infections in people. Nonetheless a careful examination of the value of continued antibiotic use in agricultural, and in pork production in particular is warranted. Therefore, the objective of our study is to validate the productivity and economic impacts of antibiotic use for pig producers at the farm level. We use data from the NAHMS 2000 swine survey. We estimate the combined affects from antibiotics used for growth promotion (AGP) and antibiotics used for disease prevention (ADP) on 4 productivity measures. We also estimate the economic impact of AGP and ADP for individual pig producers. We estimate these 4 productivity measures using seemingly unrelated regression analysis. We evaluate 4 scenarios which ban antibiotic use, and use a simple synthetic firm partial budget to estimate the economic consequences of these scenarios. We find that pig productivity is improved with AGP, but decreased with ADP. A total ban on AGP would cost pig producers 1,271inlostprofitsper1,020headpigbarn.AtotalbanonADPhowever,wouldresultinpigproducersimprovingprofitsslightly.ThisoccursbecauseproductivityisnegativelyinfluencedbyADP.AbanofbothAGPandADPresultsinasmalllossofproducerprofits(1,271 in lost profits per 1,020 head pig barn. A total ban on ADP however, would result in pig producers improving profits slightly. This occurs because productivity is negatively influenced by ADP. A ban of both AGP and ADP results in a small loss of producer profits (376/1,020 head barn) because of the offsetting effects of ADP compared to AGP. Producers have higher profits when AGP and ADP are applied at levels where pig productivity is maximized. In this case, producers gain $4,146 for each 1,020 head barn compared to no antibiotic use.Livestock Production/Industries,

    Parameters of oxidative stress in saliva from patients with aggressive and chronic periodontitis

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    Objectives: Free radicals play an important role in the onset and progression of many diseases. The aim ofthis study was to investigate the contribution of oxidative stress in the pathology of aggressive (AgP) andchronic (CP) periodontitis and its relation with the clinical periodontal status.Methods: Eighty subjects were divided into two groups: 20 patients with AgP and 20 patients with CP withtheir 20 corresponding matched controls, based on clinical attachment loss (CAL), probing pocket depth(PPD), and bleeding on probing (BOP). Saliva reactive oxygen species (ROS), lipid peroxidation, and nonenzymaticantioxidant defences were measured by luminol-dependent chemiluminescence assay, asthiobarbituric acid-reactive substances (TBARs) and total radical-trapping antioxidant potential (TRAP),respectively. Pearson?s correlation and multivariate analysis were used to determine the relationshipbetween ROS and TBARs and the clinical parameters.Results: ROS and TBARs were increased in AgP while TRAP was decreased, comparing with CP. In AgP, astrong and positive correlation was observed between ROS and TBARs and they were closely associatedwith CAL and PPD.Discussion: In AgP, but not in CP, oxidative stress is a high contributor to periodontal pathology and it isclosely associated with the clinical periodontal status.Fil: Acquier, Andrea Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: de Couto Pita, Alejandra Karina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; ArgentinaFil: Busch, Lucila. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; ArgentinaFil: Sanchez, Gabriel A.. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Biofísica; Argentin

    S-Nitrosated alpha-1-acid glycoprotein exhibits antibacterial activity against multidrug-resistant bacteria strains and synergistically enhances the effect of antibiotics

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    Alpha-1-acid glycoprotein (AGP) is a major acute-phase protein. Biosynthesis of AGP increases markedly during inflammation and infection, similar to nitric oxide (NO) biosynthesis. AGP variant A (AGP) contains a reduced cysteine (Cys149). Previously, we reported that S-nitrosated AGP (SNO-AGP) synthesized by reaction with a NO donor, possessed very strong broad-spectrum antimicrobial activity (IC50 = 10−9-10−6 M). In this study, using a cecal ligation and puncture animal model, we confirmed that AGP can be endogenously S-nitrosated during infection. Furthermore, we examined the antibacterial property of SNO-AGP against multidrug-resistant Klebsiella pneumoniae and Pseudomonas aeruginosa to investigate the involvement of SNO-AGP in the host defense system. Our results showed that SNO-AGP could inhibit multidrug efflux pump, AcrAB-TolC, a major contributor to bacterial multidrug resistance. In addition, SNO-AGP decreased biofilm formation and ATP level in bacteria, indicating that SNO-AGP can revert drug resistance. It was also noteworthy that SNO-AGP showed synergistic effects with the existing antibiotics (oxacillin, imipenem, norfloxacin, erythromycin, and tetracycline). In conclusion, SNO-AGP participated in the host defense system and has potential as a novel agent for single or combination antimicrobial therapy

    The Prevalence of Latent Mycobacterium Tuberculosis Infection Based on an Interferon-γ Release Assay: A Cross-Sectional Survey Among Urban Adults in Mwanza, Tanzania.

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    One third of the world's population is estimated to be latently infected with Mycobacterium tuberculosis (LTBI). Surveys of LTBI are rarely performed in resource poor TB high endemic countries like Tanzania although low-income countries harbor the largest burden of the worlds LTBI. The primary objective was to estimate the prevalence of LTBI in household contacts of pulmonary TB cases and a group of apparently healthy neighborhood controls in an urban setting of such a country. Secondly we assessed potential impact of LTBI on inflammation by quantitating circulating levels of an acute phase reactant: alpha-1-acid glycoprotein (AGP) in neighborhood controls. The study was nested within the framework of two nutrition studies among TB patients in Mwanza, Tanzania. Household contacts- and neighborhood controls were invited to participate. The study involved a questionnaire, BMI determination and blood samples to measure AGP, HIV testing and a Quantiferon Gold In tube (QFN-IT) test to detect signs of LTBI. 245 household contacts and 192 neighborhood controls had available QFN-IT data. Among household contacts, the proportion of QFT-IT positive was 59% compared to 41% in the neighborhood controls (p = 0.001). In a linear regression model adjusted for sex, age, CD4 and HIV, a QFT-IT positive test was associated with a 10% higher level of alpha-1-acid glycoprotein(AGP) (10(B) 1.10, 95% CI 1.01; 1.20, p = 0.03), compared to individuals with a QFT-IT negative test. LTBI is highly prevalent among apparently healthy urban Tanzanians even without known exposure to TB in the household. LTBI was found to be associated with elevated levels of AGP. The implications of this observation merit further studies

    Turnitin – The Physiological Responses to Dietary Administration of Zinc Bacitracin and Bacillus Mixture on Low-Weight Day-Old Chicks.

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    This study investigated the responses of low-weight day-old chicks to zinc bacitracin and Bacillus mixture on growth performance, hematology, intestinal selected microbiota populations, and carcass characteristics. A total of 192 unsexed Lohman MB-202 day-old broiler chicks were randomly allotted to four dietary treatment groups of 48 chicks each (6 replicates of 8 chicks) and fed for 35 days. The four treatments were CONT (basal diet without supplementation), AGP (basal diet with 0.04% zinc bacitracin), PROB (basal diet supplemented with 0.5% Bacillus mixture), and PROB+AGP (basal diet supplemented with 0.5% Bacillus mixture and 0.04% zinc bacitracin). There were no significant differences in final body weight, feed intake, and feed conversion ratio of broilers. The relative weight of thymus was higher (P= 0.01) in AGP than that in PROB and PROB+AGP birds. Birds in PROB+AGP had lower (P= 0.04) values of alanine aminotransferase (ALT) enzyme compared to those in CONT and AGP groups, but the difference was not significant when compared with birds in PROB group. Serum creatinine was lower (P < 0.01) in PROB+AGP than in CONT and AGP birds. Birds in AGP group tended (P = 0.09) to have higher globulin concentration in the serum compared to other birds. There was also a tendency (P = 0.07) for PROB+AGP birds to have higher albumin to globulin ratio compared with other birds. There was more lactic acid bacteria in ileal digesta (P = 0.05) in PROB+AGP than in AGP birds, but the difference was not significant when compared to CONT and PROB birds. Birds in AGP group had higher (P = 0.05) relative breast weight compared to other birds. In conclusion, Bacillus mixture did not affect performance and hematological parameters, but increased the intestinal population of lactic acid bacteria in broiler chicks

    Comparison of Methods for the Purification of Alpha-1 Acid Glycoprotein from Human Plasma

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    Alpha-1 acid glycoprotein (AGP) is a highly glycosylated, negatively charged plasma protein suggested to have anti-inflammatory and/or immunomodulatory activities. Purification of AGP could be simplified if methods that exploit its high solubility under chemically harsh conditions could be demonstrated to leave the protein in its native conformation. Procedures involving exposure of AGP to hot phenol or sulphosalicylic acid (SSA) were compared to solely chromatographic methods. Hot phenol-purified AGP was more rapidly cleared from mice in vivo following intravenous injection than chromatographically purified AGP. In contrast, SSA-purified AGP demonstrated an identical in vivo clearance profile and circular dichroism spectrum to chromatographically purified AGP. Similarly, no differences in susceptibility to enzymatic deglycosylation or reactivity with Sambucus nigra lectin were detected between AGP purified via the two methods. Incorporation of the SSA step in the purification scheme for AGP eliminated the need for a large (4 mL resin/mL of plasma) initial chromatographic step and simplified its purification without causing any detectable distortion in the conformation of the protein. Confirmation that this procedure is nondenaturing will simplify AGP purification and investigation of its possible biological roles in laboratory animals

    Facets for Art Gallery Problems

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    The Art Gallery Problem (AGP) asks for placing a minimum number of stationary guards in a polygonal region P, such that all points in P are guarded. The problem is known to be NP-hard, and its inherent continuous structure (with both the set of points that need to be guarded and the set of points that can be used for guarding being uncountably infinite) makes it difficult to apply a straightforward formulation as an Integer Linear Program. We use an iterative primal-dual relaxation approach for solving AGP instances to optimality. At each stage, a pair of LP relaxations for a finite candidate subset of primal covering and dual packing constraints and variables is considered; these correspond to possible guard positions and points that are to be guarded. Particularly useful are cutting planes for eliminating fractional solutions. We identify two classes of facets, based on Edge Cover and Set Cover (SC) inequalities. Solving the separation problem for the latter is NP-complete, but exploiting the underlying geometric structure, we show that large subclasses of fractional SC solutions cannot occur for the AGP. This allows us to separate the relevant subset of facets in polynomial time. We also characterize all facets for finite AGP relaxations with coefficients in {0, 1, 2}. Finally, we demonstrate the practical usefulness of our approach. Our cutting plane technique yields a significant improvement in terms of speed and solution quality due to considerably reduced integrality gaps as compared to the approach by Kr\"oller et al.Comment: 29 pages, 18 figures, 1 tabl

    Comparison of Initial Periodontal Therapy Outcome in Aggressive and Chronic Periodontitis

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    Upalne bolesti parodonta globalni su problem zdravstvene zaštite i jedan su od glavnih uzroka gubitka zuba. Ispitali smo uspješnost inicijalne terapije u oboljelih od kroničnoga parodontitisa (KP) i agresivnoga parodontitisa (AgP), te usporedili klinički odgovor među ispitivanim nskupinama raščlambom dubine sondiranja parodontnih džepova prije i poslije terapije, kao najvažnijega kliničkog indeksa za predikciju daljnje progresije bolesti. Istraživanje je provedeno na 35 pacijenata oboljelih od AgP-a i 71 oboljelog od KP-a. U oboljelih od AgP-a terapija je uključivala sustavski antibiotik i lokalnu irigaciju otopinom klorheksidina. Ispitanici s AgP-om imali su znatno dublje džepove od ispitanika s KP-om (4,49 ± 0,93 mm za AgP i 3,87 ± 0,78 mm za KP). Inicijalna je terapija u objema skupinama znatno smanjila dubinu parodontnih džepova (p < 0,001). U oboljelih od AgP a nađeno je znatno veće smanjenje dubine sondiranja nego u oboljelih od KP-a (1,05 ± 0,80 za AgP i 0,55 ± 0,69 za KP). Kada se razdvoje plitki i duboki džepovi, ta se razlika gubi. Kombinacija mehaničke i antimikrobne terapije u oboljelih od AgP-a poboljšala je klinički status parodonta i pružila zadovoljavajuće kliničke rezultate pa može služiti kao klinički protokol u inicijalnoj terapiji tih bolesnika.Inflammatory periodontal diseases present a global health care problem and are one of the main reasons for tooth loss. We investigated success of the initial periodontal therapy in patients with chronic (CP) and aggressive (AgP) periodontitis, and compared clinical outcome between these groups. We used periodontal pockets probing depth before and after the therapy, being the most important clinical index for prediction of further disease progression. Investigation included 35 patients with AgP, and 71 patients with CP. In the AgP group the therapy included systemic antibiotics and local irrigation with chlorhexidine solution. Subjects with AgP had significantly deeper pockets than subjects with CP (4.49 ± 0.93 mm AgP group, 3.87 ± 0.78 mm CP group). The initial therapy significantly reduced periodontal pocket depth in both groups (p < 0.001). AgP subjects showed significantly higher probing depth reduction than CP subjects (1.05 ± 0.80 za AgP i 0.55 ± 0.69 za CP). When deep and shallow pockets were separated, the difference between the groups was not significant. The combination of mechanical and antimicrobial therapy in the AgP subjects improved clinical periodontal findings, provided good clinical results, and can therefore be used as a clinical protocol for the initial periodontal therapy of these patients
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