ABSTRACT
Odorant‐binding proteins (OBPs) and chemosensory proteins (CSPs) are regarded as carriers of pheromones and odorants in insect chemoreception. These proteins are typically located in ...antennae, mouth organs and other chemosensory structures; however, members of both classes of proteins have been detected recently in other parts of the body and various functions have been proposed. The best studied of these non‐sensory tasks is performed in pheromone glands, where OBPs and CSPs solubilise hydrophobic semiochemicals and assist their controlled release into the environment. In some cases the same proteins are expressed in antennae and pheromone glands, thus performing a dual role in receiving and broadcasting the same chemical message. Several reports have described OBPs and CSPs in reproductive organs. Some of these proteins are male specific and are transferred to females during mating. They likely carry semiochemicals with different proposed roles, from inhibiting other males from approaching mated females, to marking fertilized eggs, but further experimental evidence is still needed. Before being discovered in insects, the presence of binding proteins in pheromone glands and reproductive organs was widely reported in mammals, where vertebrate OBPs, structurally different from OBPs of insects and belonging to the lipocalin superfamily, are abundant in rodent urine, pig saliva and vaginal discharge of the hamster, as well as in the seminal fluid of rabbits. In at least four cases CSPs have been reported to promote development and regeneration: in embryo maturation in the honeybee, limb regeneration in the cockroach, ecdysis in larvae of fire ants and in promoting phase shift in locusts. Both OBPs and CSPs are also important in nutrition as solubilisers of lipids and other essential components of the diet. Particularly interesting is the affinity for carotenoids of CSPs abundantly secreted in the proboscis of moths and butterflies and the occurrence of the same (or very similar CSPs) in the eyes of the same insects. A role as a carrier of visual pigments for these proteins in insects parallels that of retinol‐binding protein in vertebrates, a lipocalin structurally related to OBPs of vertebrates. Other functions of OBPs and CSPs include anti‐inflammatory action in haematophagous insects, resistance to insecticides and eggshell formation. Such multiplicity of roles and the high success of both classes of proteins in being adapted to different situations is likely related to their stable scaffolding determining excellent stability to temperature, proteolysis and denaturing agents. The wide versatility of both OBPs and CSPs in nature has suggested several different uses for these proteins in biotechnological applications, from biosensors for odours to scavengers for pollutants and controlled releasers of chemicals in the environment.
Odour perception has been the object of fast growing research interest in the last three decades. Parallel to the study of the corresponding biological systems, attempts are being made to model the ...olfactory system with electronic devices. Such projects range from the fabrication of individual sensors, tuned to specific chemicals of interest, to the design of multipurpose smell detectors using arrays of sensors assembled in a sort of artificial nose. Recently, proteins have attracted increasing interest as sensing elements. In particular, soluble olfaction proteins, including odorant-binding proteins (OBPs) of vertebrates and insects, chemosensory proteins (CSPs) and Niemann-Pick type C2 (NPC2) proteins possess interesting characteristics for their use in sensing devices for odours. In fact, thanks to their compact structure, their soluble nature and small size, they are extremely stable to high temperature, refractory to proteolysis and resistant to organic solvents. Moreover, thanks to the availability of many structures solved both as apo-proteins and in complexes with some ligands, it is feasible to design mutants by replacing residues in the binding sites with the aim of synthesising proteins with better selectivity and improved physical properties, as demonstrated in a number of cases.
How I ventilate an obese patient Ball, Lorenzo; Pelosi, Paolo
Critical care (London, England),
05/2019, Letnik:
23, Številka:
1
Journal Article
Recenzirano
Odprti dostop
An increasing number of patients admitted to the intensive care unit are obese 1. Many of them require mechanical ventilation, which may promote ventilator-induced lung injury (VILI) when applied to ...both injured and healthy lungs. Obesity induces functional changes in the respiratory system, resulting in a reduction of the end-expiratory lung volume, increased incidence of airway closure and formation of atelectasis, and alterations in lung and chest wall mechanics 2. These alterations explain the high occurrence of gas exchange impairment, respiratory mechanics alterations, and hemodynamic compromise. To approach to the obese patient requiring mechanical ventilation, we propose a schematic algorithm (i-STAR, Fig. 1) as follows: (1) induction and intubation, (2) setting up initial mechanical ventilation, (3) titrating mechanical ventilation parameters, (4) assessing harmfulness of mechanical ventilation, and (5) rescue strategies.
The World Health Organization defines overweight and obesity as the condition where excess or abnormal fat accumulation increases risks to health. The prevalence of obesity is increasing worldwide ...and is around 20% in ICU patients. Adipose tissue is highly metabolically active, and especially visceral adipose tissue has a deleterious adipocyte secretory profile resulting in insulin resistance and a chronic low-grade inflammatory and procoagulant state. Obesity is strongly linked with chronic diseases such as type 2 diabetes, hypertension, cardiovascular diseases, dyslipidemia, non-alcoholic fatty liver disease, chronic kidney disease, obstructive sleep apnea and hypoventilation syndrome, mood disorders and physical disabilities. In hospitalized and ICU patients and in patients with chronic illnesses, a J-shaped relationship between BMI and mortality has been demonstrated, with overweight and moderate obesity being protective compared with a normal BMI or more severe obesity (the still debated and incompletely understood “obesity paradox”). Despite this protective effect regarding mortality, in the setting of critical illness morbidity is adversely affected with increased risk of respiratory and cardiovascular complications, requiring adapted management. Obesity is associated with increased risk of AKI and infection, may require adapted drug dosing and nutrition and is associated with diagnostic and logistic challenges. In addition, negative attitudes toward obese patients (the social stigma of obesity) affect both health care workers and patients.
Anti-inflammatory properties of anesthetic agents Cruz, Fernanda Ferreira; Rocco, Patricia Rieken Macedo; Pelosi, Paolo
Critical care (London, England),
03/2017, Letnik:
21, Številka:
1
Journal Article
Recenzirano
Odprti dostop
This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2017. Other selected articles can be found online at ...http://ccforum.com/series/annualupdate2017 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901 .
The aim of this study was to conduct a meta-analysis to determine whether percutaneous tracheostomy (PT) techniques are advantageous over surgical tracheostomy (ST), and if one PT technique is ...superior to the others.
Computerized databases (1966 to 2013) were searched for randomized controlled trials (RCTs) reporting complications as predefined endpoints and comparing PT and ST and among the different PT techniques in mechanically ventilated adult critically ill patients. Odds ratios (OR) and mean differences (MD) with 95% confidence interval (CI), and I(2) values were estimated.
Fourteen RCTs tested PT techniques versus ST in 973 patients. PT techniques were performed faster (MD, -13.06 minutes (95% CI, -19.37 to -6.76 (P < 0.0001)); I(2) = 97% (P < 0.00001)) and reduced odds for stoma inflammation (OR, 0.38 (95% CI, 0.19 to 0.76 (P = 0.006)); I(2) = 2% (P = 0.36)), and infection (OR, 0.22 (95% CI, 0.11 to 0.41 (P < 0.00001)); I(2) = 0% (P = 0.54)), but increased odds for procedural technical difficulties (OR, 4.58 (95% CI, 2.21 to 9.47 (P < 0.0001)); I(2) = 0% (P = 0.63)). PT techniques reduced odds for postprocedural major bleeding (OR, 0.39 (95% CI, 0.15 to 0.97 (P = 0.04)); I(2) = 0% (P = 0.69)), but not when a single RCT using translaryngeal tracheostomy was excluded (OR, 0.58 (95% CI, 0.21 to 1.63 (P = 0.30)); I(2) = 0% (P = 0.89)). Eight RCTs compared different PT techniques in 700 patients. Multiple (MDT) and single step (SSDT) dilatator techniques are associated with the lowest odds for difficult dilatation or cannula insertion (OR, 0.30 (95% CI, 0.12 to 0.80 (P = .02)); I(2) = 56% (P = 0.03)) and major intraprocedural bleeding (OR, 0.29 (95% CI, 0.10 to 0.85 (P = 0.02)); I(2) = 0% (P = 0.72)), compared to the guide wire dilatation forceps technique.
In critically ill adult patients, PT techniques can be performed faster and reduce stoma inflammation and infection but are associated with increased technical difficulties when compared to ST. Among PT techniques, MDT and SSDT were associated with the lowest intraprocedural risks and seem to be preferable.
Abstract Since their widespread introduction more than half a century ago, Intensive Care Units (ICUs) have become an integral part of the health care system. While most ICUs are found in high income ...countries, they are increasingly a feature of health care systems in low and middle income countries. The World Federation of Societies of Intensive and Critical Care Medicine (WFSICCM) convened a task force whose objective was to answer the question, “What is an ICU” in an internationally meaningful manner, and to develop a system for stratifying ICUs on the basis of the intensity of the care they provide. We undertook a scoping review of the peer-reviewed and grey literature to assemble existing models for ICU stratification. Based on these, and on discussions amongst task force members by teleconference and two face-to-face meetings, we present a proposed definition and classification of ICUs. An ICU is an organized system for the provision of care to critically ill patients that provides intensive and specialized medical and nursing care, an enhanced capacity for monitoring, and multiple modalities of physiologic organ support to sustain life during a period of life-threatening organ system insufficiency. While an ICU is based in a defined geographic area of a hospital, its activities often extend beyond the walls of the physical space to include the emergency department, hospital ward, and follow-up clinic. A Level One ICU is capable of providing oxygen, non-invasive monitoring, and more intensive nursing care than on a ward, while a Level Two ICU can provide invasive monitoring and basic life support for a short period of time. A Level Three ICU provides a full spectrum of monitoring and life support technologies, serves as a regional resource for the care of critically ill patients, and may play an active role in developing the specialty of intensive care through research and education. A formal definition and descriptive framework for ICUs can inform health care decision-makers in planning and measuring capacity, and provide clinicians and patients with a benchmark to evaluate the level of resources available for clinical care.
Cardiac arrest (CA) is a major cause of morbidity and mortality frequently associated with neurological and systemic involvement. Supportive therapeutic strategies such as mechanical ventilation, ...hemodynamic settings, and temperature management have been implemented in the last decade in post-CA patients, aiming at protecting both the brain and the lungs and preventing systemic complications. A lung-protective ventilator strategy is currently the standard of care among critically ill patients since it demonstrated beneficial effects on mortality, ventilator-free days, and other clinical outcomes. The role of protective and personalized mechanical ventilation setting in patients without acute respiratory distress syndrome and after CA is becoming more evident. The individual effect of different parameters of lung-protective ventilation, including mechanical power as well as the optimal oxygen and carbon dioxide targets, on clinical outcomes is a matter of debate in post-CA patients. The management of hemodynamics and temperature in post-CA patients represents critical steps for obtaining clinical improvement. The aim of this review is to summarize and discuss current evidence on how to optimize mechanical ventilation in post-CA patients. We will provide ten tips and key insights to apply a lung-protective ventilator strategy in post-CA patients, considering the interplay between the lungs and other systems and organs, including the brain.
IMPORTANCE: Infection is frequent among patients in the intensive care unit (ICU). Contemporary information about the types of infections, causative pathogens, and outcomes can aid the development of ...policies for prevention, diagnosis, treatment, and resource allocation and may assist in the design of interventional studies. OBJECTIVE: To provide information about the prevalence and outcomes of infection and the available resources in ICUs worldwide. DESIGN, SETTING, AND PARTICIPANTS: Observational 24-hour point prevalence study with longitudinal follow-up at 1150 centers in 88 countries. All adult patients (aged ≥18 years) treated at a participating ICU during a 24-hour period commencing at 08:00 on September 13, 2017, were included. The final follow-up date was November 13, 2017. EXPOSURES: Infection diagnosis and receipt of antibiotics. MAIN OUTCOMES AND MEASURES: Prevalence of infection and antibiotic exposure (cross-sectional design) and all-cause in-hospital mortality (longitudinal design). RESULTS: Among 15 202 included patients (mean age, 61.1 years SD, 17.3 years; 9181 were men 60.4%), infection data were available for 15 165 (99.8%); 8135 (54%) had suspected or proven infection, including 1760 (22%) with ICU-acquired infection. A total of 10 640 patients (70%) received at least 1 antibiotic. The proportion of patients with suspected or proven infection ranged from 43% (141/328) in Australasia to 60% (1892/3150) in Asia and the Middle East. Among the 8135 patients with suspected or proven infection, 5259 (65%) had at least 1 positive microbiological culture; gram-negative microorganisms were identified in 67% of these patients (n = 3540), gram-positive microorganisms in 37% (n = 1946), and fungal microorganisms in 16% (n = 864). The in-hospital mortality rate was 30% (2404/7936) in patients with suspected or proven infection. In a multilevel analysis, ICU-acquired infection was independently associated with higher risk of mortality compared with community-acquired infection (odds ratio OR, 1.32 95% CI, 1.10-1.60; P = .003). Among antibiotic-resistant microorganisms, infection with vancomycin-resistant Enterococcus (OR, 2.41 95% CI, 1.43-4.06; P = .001), Klebsiella resistant to β-lactam antibiotics, including third-generation cephalosporins and carbapenems (OR, 1.29 95% CI, 1.02-1.63; P = .03), or carbapenem-resistant Acinetobacter species (OR, 1.40 95% CI, 1.08-1.81; P = .01) was independently associated with a higher risk of death vs infection with another microorganism. CONCLUSIONS AND RELEVANCE: In a worldwide sample of patients admitted to ICUs in September 2017, the prevalence of suspected or proven infection was high, with a substantial risk of in-hospital mortality.
PDF
