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Helmet continuous positive airway pressure is a simple, noninvasive respiratory support strategy to treat several forms of acute respiratory failure, such as cardiogenic pulmonary edema and pneumonia. Recently, it has been largely used worldwide during the COVID-19 pandemic. Given the increased use of helmet continuous positive airway pressure in the emergency department, we aimed to provide an updated practical guide for nurses and clinicians based on the latest available evidence. We focus our attention on how to set the respiratory circuit. Moreover, we discuss the interactions between flow generators, filters, and positive end-expiratory pressure valves and the consequences regarding the delivered gas flow, fraction of inspired oxygen, positive end-expiratory pressure, and noise level.

BACKGROUND: When helmet CPAP is performed using a Venturi system, filters are frequently interposed in the respiratory circuit to reduce noise within the helmet. The effect of the interposition of these filters on delivered fresh gas flow and the resulting FIO2 is currently unknown. METHODS: In a bench study, 2 different Venturi systems (WhisperFlow and Harol) were used to generate 3 different gas flow/FIO2 combinations (80 L/min-FIO2 0.6, 100 L/min-FIO2 0.5, 120 L/min-FIO2 0.4). Different combinations of filters were applied at the flow generator input line and/or at the helmet inlet port. Two types of filters were used for this purpose: a heat and moisture exchanger filter and an electrostatic filter. The setup without filters was used as baseline. Gas flow and FIO2 were measured for each setup. RESULTS: Compared to baseline, the interposition of filters reduced the gas flow between 1–13% (P < .001). The application of a filter at the Venturi system or at the helmet generated a comparable flow reduction (-3 ± 2% vs-4 ± 2%, P = .12), whereas a greater flow reduction (-7 ± 4%) was observed when filters were applied at both sites (P < .001). An increase in FIO2 up to 5% was observed with filters applied. A strong inverse linear relationship (P < .001) was observed between the resulting gas flow and FIO2. CONCLUSIONS: The use of filters during helmet CPAP reduced the flow delivered to the helmet and, consequently, modified FIO2. If filters are applied, an adequate gas flow should be administered to guarantee a constant CPAP during the entire respiratory cycle and avoid rebreathing. Moreover, it might be important to measure the effective FIO2 delivered to the patient to guarantee a precise assessment of oxygenation.

Objective: To assess the different effect of filters’ application during helmet-CPAP delivered with three different flow generators on the delivered fresh gas flow, FiO2, and the noise level inside and outside the helmet. Methods: In a bench study, three flow generators (air-oxygen blender, turbine ventilator and Venturi system) were used to generate two different gas flows (60 L/min and 80 L/min), with a fixed FiO2 at 0.6, to perform a helmet-CPAP on a manikin. Three different fixed PEEP valves (7.5, 10, and 12.5 cmH2O) were applied at the expiratory port. Gas flow, FiO2 and noise were recorded for each Flow-generator/Flow/PEEP combination, first without filter interposition and then after positioning a heat and moister exchanger filter (HMEF) at the helmet inlet port. Results: The application of the HMEF lead to a significant difference in the flow variation among the three flow generators (p < 0.001). Compared to baseline, the highest flow reduction was observed with the VENTURI (−13.4 ± 1.2 %, p < 0.001), a slight increase with the BLENDER (1.2 ± 0.5 %, p < 0.001), whereas no difference was recorded with the TURBINE (0.1 ± 0.6 %, p = 0.12). After HMEF was interposed, a significant FiO2 variation was observed only with VENTURI (11.3 ± 1.8 %, p < 0.001). As for the noise, the TURBINE was the least noisy system, both with and without the filter interposition. Conclusions: Flow generators used to deliver helmet-CPAP have different characteristics and responses to HMEF interposition. Users should be aware of the effects on FiO2 and flow of the different devices in order to make a precise setup of the circuit.

Employing qualitative empirical data collected in Italy and England for a doctoral research on small-scale primary food producers in the alternative food economy, this chapter provides an interpretation of the peculiar nature of the entrepreneurialism that characterizes those small-scale farmers who entrust their economic reproduction (at least partially) to short, direct supply chains and alternative food networks (AFNs). The chapter summarizes the strategies implemented by farmers to ‘go alternative' as well as the subsequent transformation of growing and business practices that such a process entails, for then comparing the researcher's empirical results with four studies on farmers' entrepreneurialism. Issues of care, trust, change-orientedness, risk-taking, lifestyle, and autonomy are discussed, and farmers' entrepreneurial spirit is found to be cautious, due to the interplay of a traditional farming business orientation, a more pronounced relational disposition, and the characteristics and requirements of the alternative economy in which farmers are embedded.

Pantothenate kinase-associated neurodegeneration (PKAN) is a neurodegenerative disease belonging to the group of neurodegeneration with brain iron accumulation disorders. It is characterized by progressive impairments in movement, speech and cognition. The disease is inherited in a recessive manner due to mutations in the Pantothenate Kinase-2 (PANK2) gene that encodes a mitochondrial protein involved in Coenzyme A synthesis. To investigate the link between a PANK2 gene defect and iron accumulation, we analyzed primary skin fibroblasts from three PKAN patients and three unaffected subjects. The oxidative status of the cells and their ability to respond to iron were analyzed in both basal and iron supplementation conditions. In basal conditions, PKAN fibroblasts show an increase in carbonylated proteins and altered expression of antioxidant enzymes with respect to the controls. After iron supplementation, the PKAN fibroblasts had a defective response to the additional iron. Under these conditions, ferritins were up-regulated and Transferrin Receptor 1 (TfR1) was down-regulated to a minor extent in patients compared with the controls. Analysis of iron regulatory proteins (IRPs) reveals that, with respect to the controls, PKAN fibroblasts have a reduced amount of membrane-associated mRNA-bound IRP1, which responds imperfectly to iron. This accounts for the defective expression of ferritin and TfR1 in patients cells. The inaccurate quantity of these proteins produced a higher bioactive labile iron pool and consequently increased iron-dependent reactive oxygen species formation. Our results suggest that Pank2 deficiency promotes an increased oxidative status that is further enhanced by the addition of iron, potentially causing damage in cells.

We tried to identify the target/s of autoantibodies to basal ganglia neurons found in a patient with hyperkinetic movement disorders (HMD) characterized by rapid, rhythmic involuntary movements or spasms in both face and neck. Patient and control sera were used in Western blot to probe mouse brain homogenates. Two-dimensional gel electrophoresis (2-DE) SDS-PAGE protein spots recognized by the patient's antibodies were excised and sequenced by mass spectrometry analysis, and the glycolytic enzyme aldolase A was identified as the antigen recognized by the patient's autoantibodies. To assess relevance and specificity of these antibodies to the identified targets as biomarkers of autoimmunity in movement disorders, autoantibody responses to the identified target were then measured by ELISA in various diseases of the central nervous system. Anti-aldolase A autoantibodies were associated mainly with HMD (7/17, 41%) and Parkinson's disease (4/30, 13%) patients, and undetectable in subjects with other inflammatory and non-inflammatory central nervous system diseases. We, thus, identified aldolase A as an autoantigen in a sub-group of patients with HMD, a clinically ill-defined syndrome. Anti-aldolase A antibodies may represent a useful biomarker of autoimmunity in HMD patients.

Human L-ferritin deficiency causes reduced cellular iron availability and increased ROS production with enhanced oxidized proteins, which results in idiopathic generalized seizures and atypical restless leg syndrome., The ubiquitously expressed iron storage protein ferritin plays a central role in maintaining cellular iron homeostasis. Cytosolic ferritins are composed of heavy (H) and light (L) subunits that co-assemble into a hollow spherical shell with an internal cavity where iron is stored. The ferroxidase activity of the ferritin H chain is critical to store iron in its Fe3+ oxidation state, while the L chain shows iron nucleation properties. We describe a unique case of a 23-yr-old female patient affected by a homozygous loss of function mutation in the L-ferritin gene, idiopathic generalized seizures, and atypical restless leg syndrome (RLS). We show that L chain ferritin is undetectable in primary fibroblasts from the patient, and thus ferritin consists only of H chains. Increased iron incorporation into the FtH homopolymer leads to reduced cellular iron availability, diminished levels of cytosolic catalase, SOD1 protein levels, enhanced ROS production and higher levels of oxidized proteins. Importantly, key phenotypic features observed in fibroblasts are also mirrored in reprogrammed neurons from the patient’s fibroblasts. Our results demonstrate for the first time the pathophysiological consequences of L-ferritin deficiency in a human and help to define the concept for a new disease entity hallmarked by idiopathic generalized seizure and atypical RLS.

Background: Antibodies against aquaporin-4 (AQP4), a water channel particularly expressed on perivascular astrocytic podocytes, are proposed as a marker for the diagnosis of neuromyelitis optica (NMO). However, a consensus on seroprevalence and optimal detection method has not yet been reached. Objectives: To investigate the performance of different assays to detect anti-AQP4 antibodies. Methods: We set up five different assays. Two of them were capable to detect perivascular IgG reactivity on brain tissue by immunofluorescence (NMO-IgG). Other three assays have been set to detect anti-AQP4 antibodies: immunofluorescence and flow cytometry on AQP4-expressing cells, and a radioimmunoprecipitation assay. We assessed sensitivity and specificity of these assays by interrogating sera of 33 NMO patients, 13 patients at high risk to develop NMO (hrNMO), 6 patients affected by acute partial transverse myelitis (APTM), 20 patients with multiple sclerosis (MS), and 67 age- and sex-matched healthy controls. Results: We found that the presence of serum NMO-IgG and anti-AQP4 reactivity is almost exclusively restricted to patients with NMO and hrNMO. Seroprevalence and sensitivity ranged from 30 to 47%, depending on the assay. Specificity ranged from 95 to 100%. Comparing results obtained in the five assays, we noticed lack of concordance in some samples. Conclusions: Detection of NMO-IgG or anti-AQP4 antibodies may represent a valuable tool to assist neurologists in the differential diagnosis between patients with NMO, hrNMO, APTM, or MS. The current lack of a gold standard to detect anti-AQP4 antibodies implies the necessity to standardize the detection of these antibodies.