77 research outputs found

    Effects of Aluminium–Magnesium Silicate on Newcastle Disease Virus and on recovery of infected chicks

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    Effect of a synthetic Aluminium – Magnesium Silicate (AMS) on Newcastle Disease Virus (NDV) was tested. Equal amounts, of the AMS and of NDV, on a volume to weight (v/w) basis, were incubated for one hour at room temperature, and then centrifuged. The supernatant was tested for NDV titre. Portions of a virulent NDV were similarly incubated with the AMS, and their supernatants tested for morbidity rates on infected chicks. Also, two groups of chicks were infected with virulent NDV intramuscularly (I/m), and by introduction of infected chicks, respectively. Their subgroups were treated by administering AMS through drinking water, to assess its effect on mortality. Incubating NDV with AMS, reduced the viral titre from mean HA, 613 ±86 to 4. 5 ±0.72 (P < 0.05). Also, incubating virulent NDV with the AMS, reduced its morbidity rate from 100% to 20% (P< 0.05) when incubated once, and from 100% to zero, when incubated twice. NDV- infected chicks treated with AMS, had same 100% mortality as the controls, when route of infection was I/m (P > 0.05) but when infection was by introduction of infected chicks, mortality reduced from 20% to zero (P < 0.05).These results suggest AMS as NDV’s antiviral agent

    Mechanistic insight into the sensing of nitroaromatic compounds by metal-organic frameworks

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    There has been extensive research on the sensing of explosive nitroaromatic compounds (NACs) using fluorescent metal-organic frameworks (MOFs). However, ambiguity in the sensing mechanism has hampered the development of efficient explosive sensors. Here we report the synthesis of a hydroxyl-functionalized MOF for rapid and efficient sensing of NACs and examine in detail its fluorescence quenching mechanisms. In chloroform, quenching takes place primarily by exciton migration to the ground-state complex formed between the MOF and the analytes. A combination of hydrogen-bonding interactions and ??????? stacking interactions are responsible for fluorescence quenching, and this observation is supported by single-crystal structures. In water, the quenching mechanism shifts toward resonance energy transfer and photo-induced electron transfer, after exciton migration as in chloroform. This study provides insight into florescence-quenching mechanisms for the selective sensing of NACs and reduces the ambiguity regarding the nature of interactions between the MOF and NACs

    Influenza A Virus Inhibits Type I IFN Signaling via NF-κB-Dependent Induction of SOCS-3 Expression

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    The type I interferon (IFN) system is a first line of defense against viral infections. Viruses have developed various mechanisms to counteract this response. So far, the interferon antagonistic activity of influenza A viruses was mainly observed on the level of IFNβ gene induction via action of the viral non-structural protein 1 (NS1). Here we present data indicating that influenza A viruses not only suppress IFNβ gene induction but also inhibit type I IFN signaling through a mechanism involving induction of the suppressor of cytokine signaling-3 (SOCS-3) protein. Our study was based on the observation that in cells that were infected with influenza A virus and subsequently stimulated with IFNα/β, phosphorylation of the signal transducer and activator of transcription protein 1 (STAT1) was strongly reduced. This impaired STAT1 activation was not due to the action of viral proteins but rather appeared to be induced by accumulation of viral 5′ triphosphate RNA in the cell. SOCS proteins are potent endogenous inhibitors of Janus kinase (JAK)/STAT signaling. Closer examination revealed that SOCS-3 but not SOCS-1 mRNA levels increase in an RNA- and nuclear factor kappa B (NF-κB)-dependent but type I IFN-independent manner early in the viral replication cycle. This direct viral induction of SOCS-3 mRNA and protein expression appears to be relevant for suppression of the antiviral response since in SOCS-3 deficient cells a sustained phosphorylation of STAT1 correlated with elevated expression of type I IFN-dependent genes. As a consequence, progeny virus titers were reduced in SOCS-3 deficient cells or in cells were SOCS-3 expression was knocked-down by siRNA. These data provide the first evidence that influenza A viruses suppress type I IFN signaling on the level of JAK/STAT activation. The inhibitory effect is at least in part due to the induction of SOCS-3 gene expression, which results in an impaired antiviral response

    Bone mineral density in partially recovered early onset anorexic patients - a follow-up investigation

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    <p>Abstract</p> <p>Background and aims</p> <p>There still is a lack of prospective studies on bone mineral development in patients with a history of early onset Anorexia nervosa (AN). Therefore we assessed associations between bone mass accrual and clinical outcomes in a former clinical sample. In addition to an expected influence of regular physical activity and hormone replacement therapy, we explored correlations with nutritionally dependent hormones.</p> <p>Methods</p> <p>3-9 years (mean 5.2 ± 1.7) after hospital discharge, we re-investigated 52 female subjects with a history of early onset AN. By means of a standardized approach, we evaluated the general outcome of AN. Moreover, bone mineral content (BMC) and bone mineral density (BMD) as well as lean and fat mass were measured by dual-energy x-ray absorptiometry (DXA). In a substudy, we measured the serum concentrations of leptin and insulin-like growth factor-I (IGF-I).</p> <p>Results</p> <p>The general outcome of anorexia nervosa was good in 50% of the subjects (BMI ≥ 17.5 kg/m<sup>2</sup>, resumption of menses). Clinical improvement was correlated with BMC and BMD accrual (χ<sup>2 </sup>= 5.62/χ<sup>2 </sup>= 6.65, p = 0.06 / p = 0.036). The duration of amenorrhea had a negative correlation with BMD (r = -.362; p < 0.01), but not with BMC. Regular physical activity tended to show a positive effect on bone recovery, but the effect of hormone replacement therapy was not significant. Using age-related standards, the post-discharge sample for the substudy presented IGF-I levels below the 5<sup>th </sup>percentile. IGF-I serum concentrations corresponded to the general outcome of AN. By contrast, leptin serum concentrations showed great variability. They correlated with BMC and current body composition parameters.</p> <p>Conclusions</p> <p>Our results from the main study indicate a certain adaptability of bone mineral accrual which is dependent on a speedy and ongoing recovery. While leptin levels in the substudy tended to respond immediately to current nutritional status, IGF-I serum concentrations corresponded to the individual's age and general outcome of AN.</p

    Adiposity, hormone replacement therapy use and breast cancer risk by age and hormone receptor status: a large prospective cohort study

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    INTRODUCTION: Associations of hormone-receptor positive breast cancer with excess adiposity are reasonably well characterized; however, uncertainty remains regarding the association of body mass index (BMI) with hormone-receptor negative malignancies, and possible interactions by hormone replacement therapy (HRT) use. METHODS: Within the European EPIC cohort, Cox proportional hazards models were used to describe the relationship of BMI, waist and hip circumferences with risk of estrogen-receptor (ER) negative and progesterone-receptor (PR) negative (n = 1,021) and ER+PR+ (n = 3,586) breast tumors within five-year age bands. Among postmenopausal women, the joint effects of BMI and HRT use were analyzed. RESULTS: For risk of ER-PR- tumors, there was no association of BMI across the age bands. However, when analyses were restricted to postmenopausal HRT never users, a positive risk association with BMI (third versus first tertile HR = 1.47 (1.01 to 2.15)) was observed. BMI was inversely associated with ER+PR+ tumors among women aged ≤49 years (per 5 kg/m2 increase, HR = 0.79 (95%CI 0.68 to 0.91)), and positively associated with risk among women ≥65 years (HR = 1.25 (1.16 to 1.34)). Adjusting for BMI, waist and hip circumferences showed no further associations with risks of breast cancer subtypes. Current use of HRT was significantly associated with an increased risk of receptor-negative (HRT current use compared to HRT never use HR: 1.30 (1.05 to 1.62)) and positive tumors (HR: 1.74 (1.56 to 1.95)), although this risk increase was weaker for ER-PR- disease (Phet = 0.035). The association of HRT was significantly stronger in the leaner women (BMI ≤22.5 kg/m2) than for more overweight women (BMI ≥25.9 kg/m2) for, both, ER-PR- (HR: 1.74 (1.15 to 2.63)) and ER+PR+ (HR: 2.33 (1.84 to 2.92)) breast cancer and was not restricted to any particular HRT regime. CONCLUSIONS: An elevated BMI may be positively associated with risk of ER-PR- tumors among postmenopausal women who never used HRT. Furthermore, postmenopausal HRT users were at an increased risk of ER-PR- as well as ER+PR+ tumors, especially among leaner women. For hormone-receptor positive tumors, but not for hormone-receptor negative tumors, our study confirms an inverse association of risk with BMI among young women of premenopausal age. Our data provide evidence for a possible role of sex hormones in the etiology of hormone-receptor negative tumors

    An Analysis of Benefit and Cost of Local Chicken Production By the Adopters and on– Adopters of ewcastle Disease Vaccination in Kogi – State, Nigeria

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    Newcastle disease (ND) has high seroprevalence rate and inflicts heavy economic losses on poultry as often the case in rural poultry production. This study examined the socialeconomic characteristics of the respondents and the benefit/ cost analysis of rural chicken farmers in two local council areas of Kogi State of igeria which were selected by purposive sampling and 122 respondents were administered structured questionnaires. They comprised 61 farmers’ tagged adopters of immunization against ND by vaccinations and 61 non-adopters. Educational status and farming experience were found to influence adoption of ND vaccination as immunization against ewcastle disease which in turn had positive and significant (P&lt;0.05) influence on the income of rural chicken farmers in Lokoja and Dekina Local Government Areas selected for the study. Flock size of the vaccinated chickens also significantly (P&lt;0.01) influenced income generation. The cost benefit ratio of the adopters was 2.42:1 as against 1.11:1 of non adopters. Cost of transportation for pooling birds to a centre for vaccination was responsible for 9.5% of total variable cost. It is recommended that extension agents should intensify effort to educate farmers on the incremental benefit of vaccination against the disease and that government should organize the rural chicken farmers into co-operative for visitation by veterinary extension specialist to reduce cost of immunization, encourage job creation for an improved rural economy.Key words: Benefit/Cost, Adopters, on-Adopters, ewcastle Disease, Immunizatio
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