4,957 research outputs found
Analysis of Phytoestrogens by High Performance Liquid Chromatography
Phytoestrogens are biochemicals synthesized in plants which mimic steroidal estrogen activity in mammals. Analysis of these compounds in the legumes which produce them and in body fluids is important to the study of their physiological effects. High pressure liquid chromatography (HPLC) has been found to be an efficient and sensitive method of identification and quantitation of isoflavonoids, one class of phytoestrogen. Here we report the separation of three isoflavonoids, biochanin A, genistein and daidzein using an HPLC system with a Cg reverse phase column and a linear gradient mobile phase containing acetonitrile and acetic acid/water (10/90, v/v) over 60 minutes. Minimum detection limits for the three isoflavonoids were 0.556 mug/mL, 0.314 mug/mL, and 0.377 mug/mL, respectively. This method was used to measure the concentrations of isoflavonoids in two types of soy meal and in several animal feeds. Projected use of this assay includes studies of reproductive ability following ingestion of these isoflavonoids in domestic ruminants and in wild rodents
PROGNOSTIC VALUE OF MOTOR EVOKED POTENTIALS IN MOTOR FUNCTION RECOVERY OF UPPER LIMB AFTER STROKE
Objective: To determine the prognostic value of clinical assessment and motor evoked potentials for upper limb strength and functional recovery after acute stroke, and to establish the possible use of motor evoked potentials in rehabilitation. Design: A prospective study. Subjects: Fifty-two patients with hemiparesis were enrolled one month post-stroke; 38 patients concluded the study at 12 months. Methods: Motor evoked potentials were recorded at baseline and after one month. Upper limb muscular strength (Medical Research Council Scale, MRC) and functional tests (Frenchay Arm Test, Barthel Index) were used as dependent outcome variables 12 months later. Motor evoked potentials were classified as present or absent. Predictive values of motor evoked potentials and MRC were evaluated. Results: At 12 months, patients with baseline recordable motor evoked potentials showed a good functional recovery (positive predictive value 94%). The absence of motor evoked potentials did not exclude muscular strength recovery (negative predictive value 95%). Motor evoked potentials had a higher positive predictive value than MRC only in patients with MRC < 2. Conclusion: Motor evoked potentials could be a supportive tool to increase the prognostic accuracy of upper limb motor and functional outcome in hemiparetic patients, especially those with severe initial paresis (MRC < 2) and/or with motor evoked potentials absent in the post-stroke acute phase
ERC-ESICM guidelines for prognostication after cardiac arrest: time for an update
About two-thirds of patients who are comatose after resuscitation from cardiac arrest die before hospital discharge, of whom two-thirds die from neurological injury. In these patients, prognostication is crucial in informing clinicians and patient’s relatives. Recently, three studies from different groups of investigators have retrospectively assessed the accuracy of the 2015 ERC-ESICM prognostication algorithm. All these studies consistently confirmed the accuracy of the ERC-ESICM multimodal prognostication strategy in avoiding a falsely pessimistic prediction. Interestingly, this high specificity was confirmed when the 2014 criteria for malignant EEG were replaced with a more recent classification of EEG pattern. Besides improving sensitivity of prediction, this classification also enables a good interrater reliability, favouring guidelines’ implementation
Physician Attitudes Toward the Ethics of Pre-exposure Prophylaxis (PrEP): Cost, Safety, and Resource Allocation
Background: In the United States, human immunodeficiency virus (HIV) remains a substantial public health issue. There is evidence that the use of antiretroviral medications such as pre-exposure prophylaxis (PrEP) can be a safe and effective primary prevention strategy to reduce new cases of HIV infection. Provider practice behavior as it relates to prescribing PrEP and the potential impact on specific vulnerable populations needs increased attention. Few studies have evaluated the attitudes of physicians towards ethical issues related to prescribing PrEP.
Methods: The purpose of the present literature review was to evaluate provider attitudes toward the ethics of prescribing PrEP for individuals at risk of acquiring HIV infection. Searches of the PubMed and Cochrane databases were conducted. Three reviewers independently assessed the relevance of articles and discarded those not directly related to the attitudes of physicians toward ethics of the cost, safety, and resource allocation of PrEP. A total of twenty-one articles were included in the review.
Results: Provider attitudes and perceptions focused on three areas: resource allocation, cost, and safety or effectiveness of PrEP. Providers who were hesitant in prescribing PrEP were concerned with the availability of resources, patient adherence, risk of drug resistance, and toxicity. In the studies reviewed, few providers had prescribed PrEP; however, prescribing practices trended upward with time and awareness.
Conclusions: Realization of the benefits of PrEP will require a utilitarian ethical approach to identifying the populations that will benefit most, monitoring for adverse effects, addressing costs, and educating and training providers to prescribe PrEP responsibly. Ensuring that PrEP fulfills its potential as part of a combination regimen for HIV prevention requires identification of additional evidence, education, support services, and resources that are needed, as well as the regulatory framework and cost scenarios for access to PrEP.
Key words: HIV, pre-exposure prophylaxis, ethics, utilitarianism, PrEP, physicia
Test beam performance of a CBC3-based mini-module for the Phase-2 CMS Outer Tracker before and after neutron irradiation
tBid induces alterations of mitochondrial fatty acid oxidation flux by malonyl-CoA-independent inhibition of carnitine palmitoyltransferase-1.
Recent studies suggest a close relationship between cell metabolism and apoptosis. We have evaluated changes in lipid metabolism on permeabilized hepatocytes treated with truncated Bid (tBid) in the presence of caspase inhibitors and exogenous cytochrome c. The measurement of b-oxidation flux by labeled palmitate demonstrates that tBid inhibits b-oxidation, thereby resulting in the accumulation of palmitoyl-coenzyme A (CoA) and depletion of acetyl-carnitine and acylcarnitines, which is pathognomonic for inhibition of carnitine palmitoyltransferase-1 (CPT-1). We also show that tBid decreases CPT-1 activity by a mechanism independent of both malonyl-CoA, the key inhibitory molecule of CPT-1, and Bak and/or Bax, but
dependent on cardiolipin decrease. Overexpression of Bcl-2, which is able to interact with CPT-1, counteracts the effects exerted by tBid on b-oxidation. The unexpected role of tBid in the regulation of lipid b-oxidation suggests a model in which tBid-induced metabolic decline leads to the accumulation of toxic lipid metabolites such as palmitoyl-CoA, which might become participants in the apoptotic pathway
Beam test performance of a prototype module with Short Strip ASICs for the CMS HL-LHC tracker upgrade
Implementation of an Optimal First-Order Method for Strongly Convex Total Variation Regularization
We present a practical implementation of an optimal first-order method, due
to Nesterov, for large-scale total variation regularization in tomographic
reconstruction, image deblurring, etc. The algorithm applies to -strongly
convex objective functions with -Lipschitz continuous gradient. In the
framework of Nesterov both and are assumed known -- an assumption
that is seldom satisfied in practice. We propose to incorporate mechanisms to
estimate locally sufficient and during the iterations. The mechanisms
also allow for the application to non-strongly convex functions. We discuss the
iteration complexity of several first-order methods, including the proposed
algorithm, and we use a 3D tomography problem to compare the performance of
these methods. The results show that for ill-conditioned problems solved to
high accuracy, the proposed method significantly outperforms state-of-the-art
first-order methods, as also suggested by theoretical results.Comment: 23 pages, 4 figure
Neurophysiological and neuroradiological test for early poor outcome (Cerebral Performance Categories 3\u20135) prediction after cardiac arrest: Prospective multicentre prognostication data
The data presented here are related to our research article entitled \u201cNeurophysiology and neuroimaging accurately predict poor neurological outcome within 24 hours after cardiac arrest: a prospective multicentre prognostication study (ProNeCA)\u201d [1]. We report a secondary analysis on the ability of somatosensory evoked potentials (SEPs), brain computed tomography (CT) and electroencephalography (EEG) to predict poor neurological outcome at 6 months in 346 patients who were comatose after cardiac arrest. Differently from the related research article, here we included cerebral performance category (CPC) 3 among poor outcomes, so that the outcomes are dichotomised as CPC 1\u20132 (absent to mild neurological disability: good outcome) vs. CPC 3\u20135 (severe neurological disability, persistent vegetative state, or death: poor outcome). The accuracy of the index tests was recalculated accordingly. A bilaterally absent/absent-pathological amplitude (AA/AP) N20 SEPs wave, a Grey Matter/White Matter (GM/WM) ratio <1.21 on brain CT and an isoelectric or burst suppression EEG predicted poor outcome with 49.6%, 42.2% and 29.8% sensitivity, respectively, and 100% specificity. The distribution of positive results of the three predictors did not overlap completely in the population of patients with poor outcome, so that when combining them the overall sensitivity raised to 61.2%
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