Sample preparation and EFTEM of meat samples for nanoparticle analysis in food

Nanoparticles are used in industry for personal care products and the preparation of food. In the latter application, their functions include the prevention of microbes' growth, increase of the foods nutritional value and sensory quality. EU regulations require a risk assessment of the nanoparticles used in foods and food contact materials before the products can reach the market. However, availability of validated analytical methodologies for detection and characterisation of the nanoparticles in food hampers appropriate risk assessment. As part of a research on the evaluation of the methods for screening and quantification of Ag nanoparticles in meat we have tested a new TEM sample preparation alternative to resin embedding and cryo-sectioning. Energy filtered TEM analysis was applied to evaluate thickness and the uniformity of thin meat layers acquired at increasing input of the sample demonstrating that the protocols used ensured good stability under the electron beam, reliable sample concentration and reproducibility

Uncertainties of size measurements in electron microscopy characterization of nanomaterials in foods

Electron microscopy is a recognized standard tool for nanomaterial characterization, and recommended by the European Food Safety Authority for the size measurement of nanomaterials in food. Despite this, little data have been published assessing the reliability of the method, especially for size measurement of nanomaterials characterized by a broad size distribution and/or added to food matrices. This study is a thorough investigation of the measurement uncertainty when applying electron microscopy for size measurement of engineered nanomaterials in foods. Our results show that the number of measured particles was only a minor source of measurement uncertainty for nanomaterials in food, compared to the combined influence of sampling, sample preparation prior to imaging and the image analysis. The main conclusion is that to improve the measurement reliability, care should be taken to consider replications and matrix removal prior to sample preparation

Phosphorylation of spore coat proteins by a family of atypical protein kinases

The modification of proteins by phosphorylation occurs in all life forms and is catalyzed by a large superfamily of enzymes known as protein kinases. We recently discovered a family of secretory pathway kinases that phosphorylate extracellular proteins. One member, family with sequence similarity 20C (Fam20C), is the physiological Golgi casein kinase. While examining distantly related protein sequences, we observed low levels of identity between the spore coat protein H (CotH), and the Fam20C-related secretory pathway kinases. CotH is a component of the spore in many bacterial and eukaryotic species, and is required for efficient germination of spores in Bacillus subtilis; however, the mechanism by which CotH affects germination is unclear. Here, we show that CotH is a protein kinase. The crystal structure of CotH reveals an atypical protein kinase-like fold with a unique mode of ATP binding. Examination of the genes neighboring cotH in B. subtilis led us to identify two spore coat proteins, CotB and CotG, as CotH substrates. Furthermore, we show that CotH-dependent phosphorylation of CotB and CotG is required for the efficient germination of B. subtilis spores. Collectively, our results define a family of atypical protein kinases and reveal an unexpected role for protein phosphorylation in spore biology

Early cerebral perfusion pressure augmentation with phenylephrine after traumatic brain injury may be neuroprotective in a pediatric swine model*

Objective: Cerebral perfusion pressureage, and current guidelines recommend maintaining cerebral perfusion pressure between 40 mm Hg–60 mm Hg. Although adult traumatic brain injury studies have observed an increased risk of complications associated with targeting a cerebral perfusion pressure \u3e70, we hypothesize that targeting a cerebral perfusion pressure of 70 mm Hg with the use of phenylephrine early after injury in the immature brain will be neuroprotective. Design: Animals were randomly assigned to injury with a cerebral perfusion pressure of 70 mm Hg or 40 mm Hg. Diffuse traumatic brain injury was produced by a single rapid rotation of the head in the axial plane. Cerebral microdialysis, brain tissue oxygen, intracranial pressure, and cerebral blood flow were measured 30 min–6 hrs postinjury. One hour after injury, cerebral perfusion pressure was manipulated with the vasoconstrictor phenylephrine. Animals were euthanized 6 hrs posttraumatic brain injury, brains fixed, and stained to assess regions of cell injury and axonal dysfunction. Setting: University center. Subject: Twenty-one 4-wk-old female swine. Measurements and Main Results: Augmentation of cerebral perfusion pressure to 70 mm Hg resulted in no change in axonal dysfunction, but significantly smaller cell injury volumes at 6 hrs postinjury compared to cerebral perfusion pressure 40 (1.1% vs. 7.4%, p \u3c .05). Microdialysis lactate/pyruvate ratios were improved at cerebral perfusion pressure 70 compared to cerebral perfusion pressure 40. Cerebral blood flow was higher in the cerebral perfusion pressure 70 group but did not reach statistical significance. Phenylephrine was well tolerated and there were no observed increases in serum lactate or intracranial pressure in either group. Conclusions: Targeting a cerebral perfusion pressure of 70 mm Hg resulted in a greater reduction in metabolic crisis and cell injury volumes compared to a cerebral perfusion pressure of 40 mm Hg in an immature swine model. Early aggressive cerebral perfusion pressure augmentation to a cerebral perfusion pressure of 70 mm Hg in pediatric traumatic brain injury before severe intracranial hypertension has the potential to be neuroprotective, and further investigations are needed

An Intervention to Debunk Facts vs. Myths in Intermittent Fasting: A Quality Improvement Project

Intermittent fasting (IF) is gaining popularity as an eating regimen to promote health and optimize wellbeing. IF is the voluntary avoidance of food over a period and is not a diet, but an eating behavior (Teong et al., 2021). Despite the increased emphasis on obesity and diet-related diseases, IF education remains lacking in formal training programs and can influence HCC’s attitudes and behaviors when engaging in IF dialogue with patients in clinical settings. Evidence suggests that IF is beneficial for weight loss and has been shown to have positive effects on the brain, heart, liver, muscles, intestines, blood, and various other systems. IF has also been shown to reduce risk factors associated with the development and progression of type II diabetes, neurological disorders, and cancers. Additionally, IF may boost the effectiveness of certain medical and cancer treatments (Armutcu, 2019; Phillips, 2019). The main objective is to determine if an evidence-based education program on intermittent fasting will change healthcare clinicians’ knowledge, attitudes, confidence level, perception of knowledge, and behavior in communicating with adult patients about IF. The presentation aims to fill the knowledge gaps with pertinent evidence-based information, debunk common IF myths, and provide effective communication strategies to help improve HCCs knowledge, attitudes, confidence, and behavior of IF in clinical practice settings. The study is a quasi-experimental, pre-test post-test quality improvement (QI) project including 20 HCCs working at the practice site. Potential participants were identified by snow-ball samplings of various units/clinics at the site. Descriptive statistics were used to analyze the data. Results from the project indicate that mean knowledge scores compared from baseline to post-education increased, 6.8 (s.d. 3.77) and 12.65 (s.d. 4.83), respectively. Based on the current evidence and the results from this quality-improvement project, HCC education helps improve knowledge, confidence, perceptions, and behaviors of IF in clinical practice settings to promote safe and effective communication with patients