65 research outputs found

    The impact of pollen consumption on honey bee (Apis mellifera) digestive physiology and carbohydrate metabolism

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    Carbohydrate-active enzymes play an important role in the honey bee (Apis mellifera) due to its dietary specialization on plant-based nutrition. Secretory glycoside hydrolases (GHs) produced in worker head glands aid in the processing of floral nectar into honey and are expressed in accordance with the age-based division of labor. Pollen utilization by the honey bee has been investigated in considerable detail, but little is known about the metabolic fate of indigestible carbohydrates and glycosides in pollen biomass. Here, we demonstrate that pollen consumption stimulates the hydrolysis of sugars that are toxic to the bee (xylose, arabinose, mannose). GHs produced in the head accumulate in the midgut and persist in the hindgut that harbors a core microbial community composed of approximately 108 bacterial cells. Pollen consumption significantly impacted total and specific bacterial abundance in the digestive tract. Bacterial isolates representing major fermentative gut phylotypes exhibited primarily membrane-bound GH activities that may function in tandem with soluble host enzymes retained in the hindgut. Additionally, we found that plant-originating -galactosidase activity in pollen may be sufficient, in some cases, for probable physiological activity in the gut. These findings emphasize the potential relative contributions of host, bacteria, and pollen enzyme activities to carbohydrate break- down, which may be tied to gut microbiome dynamics and associated host nutrition

    Selective Cholinergic Depletion in Medial Septum Leads to Impaired Long Term Potentiation and Glutamatergic Synaptic Currents in the Hippocampus

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    Cholinergic depletion in the medial septum (MS) is associated with impaired hippocampal-dependent learning and memory. Here we investigated whether long term potentiation (LTP) and synaptic currents, mediated by alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionate (AMPA) and N-methyl-D-aspartate (NMDA) receptors in the CA1 hippocampal region, are affected following cholinergic lesions of the MS. Stereotaxic intra-medioseptal infusions of a selective immunotoxin, 192-saporin, against cholinergic neurons or sterile saline were made in adult rats. Four days after infusions, hippocampal slices were made and LTP, whole cell, and single channel (AMPA or NMDA receptor) currents were recorded. Results demonstrated impairment in the induction and expression of LTP in lesioned rats. Lesioned rats also showed decreases in synaptic currents from CA1 pyramidal cells and synaptosomal single channels of AMPA and NMDA receptors. Our results suggest that MS cholinergic afferents modulate LTP and glutamatergic currents in the CA1 region of the hippocampus, providing a potential synaptic mechanism for the learning and memory deficits observed in the rodent model of selective MS cholinergic lesioning

    Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

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    Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

    Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

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    Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049

    The impact of pollen consumption on honey bee (Apis mellifera) digestive physiology and carbohydrate metabolism

    Get PDF
    Carbohydrate-active enzymes play an important role in the honey bee (Apis mellifera) due to its dietary specialization on plant-based nutrition. Secretory glycoside hydrolases (GHs) produced in worker head glands aid in the processing of floral nectar into honey and are expressed in accordance with the age-based division of labor. Pollen utilization by the honey bee has been investigated in considerable detail, but little is known about the metabolic fate of indigestible carbohydrates and glycosides in pollen biomass. Here, we demonstrate that pollen consumption stimulates the hydrolysis of sugars that are toxic to the bee (xylose, arabinose, mannose). GHs produced in the head accumulate in the midgut and persist in the hindgut that harbors a core microbial community composed of approximately 108 bacterial cells. Pollen consumption significantly impacted total and specific bacterial abundance in the digestive tract. Bacterial isolates representing major fermentative gut phylotypes exhibited primarily membrane-bound GH activities that may function in tandem with soluble host enzymes retained in the hindgut. Additionally, we found that plant-originating -galactosidase activity in pollen may be sufficient, in some cases, for probable physiological activity in the gut. These findings emphasize the potential relative contributions of host, bacteria, and pollen enzyme activities to carbohydrate break- down, which may be tied to gut microbiome dynamics and associated host nutrition

    Sero-Prevalence Of Brucellosis In Smallholder Dairy, Agropastoral, Pastoral, Beef Ranch And Wildlife Animals In Tanzania

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    A total of 2738 livestock sera from smallholder dairy, pastoral and agro-pastoral herds were screened for antibodies for Brucella spp using the Rose Bengal Plate test. Screening for Brucella antibodies was also carried out on 403 cattle sera that were purposively collected from one ranch which had a history of abortion and also from 90 wildlife animals that were darted for various purposes. The results of sero-conversion revealed that cattle, small ruminants and wildlife animals were exposed to Brucella infection, with the sero-prevalence of the infection being 6.2%, 6.5% and 13% respectively. Pastoral farming system had significantly higher Brucella antibodies (

    Adaptive optics for the 6.5 m MMT

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    The adaptive optics system for the 6.5 m MMT conversion telescope will be the first to compensate the aberrated wavefront at the telescope&apos;s secondary mirror. This approach has unique advantages in terms of optical simplicity, high throughput and low emissivity. We report here the present state of construction, and the results of static and dynamic performance tests of the Cassegrain optical package. 1. INTRODUCTION The MMT adaptive optics system is conceived as an integral part of the 6.5 m telescope. Compensation of atmospheric aberration will be done to high order at a deformable secondary mirror, 1 giving a corrected f/15 Cassegrain focus. Wavefront sensing will be done in an opto-mechanical package bolted to the instrument rotator. The lower side of the package presents a flange centered on the corrected beam to which a variety of instruments may be mounted. A number of technological challenges have had to be addressed in the design and construction of the AO system. Firstly,..
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