Coupling nanotechnology to optical affinity sensing: the case of surface plasmon resonance imaging for DNA detection

Surface Plasmon Resonance imaging (SPRi) is an advanced optical transducer for the DNA affinity biosensors. SPRi signal enhancement of a DNA biosensor is a goal in developing innovative devices, especially for clinical applications. Nanoparticles (NPs) play a forefront role in signal enhancement in biosensor-based analysis, using different transduction principles. This work focused on the use of NPs for gold chip surface nanostructuring with the aim to study influence of this modification on DNA-based sensing using SPRi transduction. In particular gold NPs of different size and materials were immobilized through dithiol layer on gold biochip surface and further functionalized with thiolated DNA probe. Plasmon curves were studied for assessing the presence of the nanostructure and the influence of the nanostructure in SPRi signal was evaluated for each structure in hybridization with complementary oligonucleotide

Improving surface plasmon resonance imaging of DNA by creating new gold and silver based surface nanostructures

The use of nanoparticles (NPs) can substantially improve the analytical performance of surface plasmon resonance imaging (SPRi) in general, and in DNA sensing in particular. In this work, we report on the modification of the gold surface of commercial biochips with gold nanospheres, silica-coated gold nanoshells, and silver nanoprisms, respectively. The NPs were tethered onto the surface of the chip and functionalized with a DNA probe. The effects of tethering conditions and varying nanostructures on the SPRi signals were evaluated via hybridization assays. The results showed that coupling between planar surface plasmons and electric fields, generated by localized surface plasmons of the NPs, is mandatory for signal enhancement. Silver nanoprisms gave the best results in improving the signal change at a target DNA concentration of <50 nM by +50 % (compared to a conventional SPRi chip). The limit of detection for the target DNA was 0.5 nM which is 5 times less than in conventional SPRi

Structural modulation of the biological activity of gold nanoparticles functionalized with a carbonic anhydrase inhibitor

Gold nanoparticles (AuNPs) have gained attention for their potential and application in different fields, e.g. nanomedicine. This study explores the surface functionalization of AuNP with inhibitors of carbonic anhydrases (CAs, EC 4.2.1.1). Some CA transmembrane isoforms have been recognized as therapeutic targets for the treatment of hypoxic tumors. Embedding a CA inhibitory function onto a nanosized unit has been proved to enable selective targeting of transmembrane isoforms. We report the preparation in aqueous media, the characterization and CA inhibition tests of AuNPs coated with a sulfonamide (SA) derivative, already known for its inhibitory activity toward CAs. The physico-chemical characterization of SA-coated AuNPs was performed with a combination of scattering and spectroscopic techniques. We detect a threshold effect of the SA concentration on the final hydrodynamic and core sizes of the capped nanoparticles and on their stability over aggregation. These modified nanoparticles were assayed for inhibition of some CA transmembrane isoforms (CA IX and XII) as well as of two cytosolic isoforms (CA I and II), and show interesting inhibitory efficiency in the submicromolar range and some selectivity for transmembrane isoforms

Tracheostomy Timing and Outcome in Severe COVID-19: The WeanTrach Multicenter Study

Background: Tracheostomy can be performed safely in patients with coronavirus disease 2019 (COVID-19). However, little is known about the optimal timing, effects on outcome, and complications. Methods: A multicenter, retrospective, observational study. This study included 153 tracheostomized COVID-19 patients from 11 intensive care units (ICUs). The primary endpoint was the median time to tracheostomy in critically ill COVID-19 patients. Secondary endpoints were survival rate, length of ICU stay, and post-tracheostomy complications, stratified by tracheostomy timing (early versus late) and technique (surgical versus percutaneous). Results: The median time to tracheostomy was 15 (1-64) days. There was no significant difference in survival between critically ill COVID-19 patients who received tracheostomy before versus after day 15, nor between surgical and percutaneous techniques. ICU length of stay was shorter with early compared to late tracheostomy (p &lt; 0.001) and percutaneous compared to surgical tracheostomy (p = 0.050). The rate of lower respiratory tract infections was higher with surgical versus percutaneous technique (p = 0.007). Conclusions: Among critically ill patients with COVID-19, neither early nor percutaneous tracheostomy improved outcomes, but did shorten ICU stay. Infectious complications were less frequent with percutaneous than surgical tracheostomy

Structural modulation of the biological activity of gold nanoparticles functionalized with a carbonic anhydrase inhibitor

Gold nanoparticles (AuNPs) have gained attention for their potential and application in different fields, e.g. nanomedicine. This study explores the surface functionalization of AuNP with inhibitors of carbonic anhydrases (CAs, EC 4.2.1.1). Some CA transmembrane isoforms have been recognized as therapeutic targets for the treatment of hypoxic tumors. Embedding a CA inhibitory function onto a nanosized unit has been proved to enable selective targeting of transmembrane isoforms. We report the preparation in aqueous media, the characterization and CA inhibition tests of AuNPs coated with a sulfonamide (SA) derivative, already known for its inhibitory activity toward CAs. The physico-chemical characterization of SA-coated AuNPs was performed with a combination of scattering and spectroscopic techniques. We detect a threshold effect of the SA concentration on the final hydrodynamic and core sizes of the capped nanoparticles and on their stability over aggregation. These modified nanoparticles were assayed for inhibition of some CA transmembrane isoforms (CA IX and XII) as well as of two cytosolic isoforms (CA I and II), and show interesting inhibitory efficiency in the submicromolar range and some selectivity for transmembrane isoforms

Estimating minimum adult HIV prevalence: A cross-sectional study to assess the characteristics of people living with HIV in Italy

In 2012, we conducted a retrospective cross-sectional study to assess the number of people living with HIV linked to care and, among these, the number of people on antiretroviral therapy. The health authority in each of the 20 Italian Regions provided the list of Public Infectious Diseases Clinics providing antiretroviral therapy and monitoring people with HIV infection. We asked every Public Infectious Diseases Clinic to report the number of HIV-positive people diagnosed and linked to care and the number of those on antiretroviral therapy during 2012. In 2012, 94,146 people diagnosed with HIV and linked to care were reported. The majority were males (70.1%), Italians (84.4%), and aged between 25 and 49 years (63.4%); the probable route of transmission was heterosexual contact in 37.5% of cases, injecting drug use in 28.1%, and male-to-male contact in 27.9%. Among people in care, 20.1% had less than 350 CD4 cells/μl, 87.6% received antiretroviral therapy, and among these, 62.4% had a CD4 cell count higher than 350 cells/μl. The overall estimated prevalence of individuals diagnosed and linked to care in 2012 in Italy was 0.16 per 100 residents (all ages). Adding the estimated proportion of undiagnosed people, the estimated HIV prevalence would range between 0.19 and 0.26 per 100 residents. In Italy, the majority of people diagnosed and linked to care receive antiretroviral therapy. A higher prevalence of individuals diagnosed and linked to care was observed in Northern Italy and among males. More information for developing the HIV care continuum is necessary to improve the entire engagement in care, focusing on test-and-treat strategies to substantially reduce the proportion of people still undiagnosed or with a detectable viral load

Efficacy and adverse events profile of videolaryngoscopy in critically ill patients: subanalysis of the INTUBE study

Background: Tracheal intubation is a high-risk procedure in the critically ill, with increased intubation failure rates and a high risk of other adverse events. Videolaryngoscopy might improve intubation outcomes in this population, but evidence remains conflicting, and its impact on adverse event rates is debated.Methods: This is a subanalysis of a large international prospective cohort of critically ill patients (INTUBE Study) performed from 1 October 2018 to 31 July 2019 and involving 197 sites from 29 countries across five continents. Our primary aim was to determine the first-pass intubation success rates of videolaryngoscopy. Secondary aims were characterising (a) videolaryngoscopy use in the critically ill patient population and (b) the incidence of severe adverse effects compared with direct laryngoscopy.Results: Of 2916 patients, videolaryngoscopy was used in 500 patients (17.2%) and direct laryngoscopy in 2416 (82.8%). First-pass intubation success was higher with videolaryngoscopy compared with direct laryngoscopy (84% vs 79%, P1/40.02). Patients undergoing videolaryngoscopy had a higher frequency of difficult airway predictors (60% vs 40%, P&lt;0.001). In adjusted analyses, videolaryngoscopy increased the probability of first-pass intubation success, with an OR of 1.40 (95% confidence interval [CI] 1.05-1.87). Videolaryngoscopy was not significantly associated with risk of major adverse events (odds ratio 1.24, 95% CI 0.95-1.62) or cardiovascular events (odds ratio 0.78, 95% CI 0.60-1.02).Conclusions: In critically ill patients, videolaryngoscopy was associated with higher first-pass intubation success rates, despite being used in a population at higher risk of difficult airway management. Videolaryngoscopy was not associated with overall risk of major adverse events

Intubation Practices and Adverse Peri-intubation Events in Critically Ill Patients from 29 Countries

Importance: Tracheal intubation is one of the most commonly performed and high-risk interventions in critically ill patients. Limited information is available on adverse peri-intubation events. Objective: To evaluate the incidence and nature of adverse peri-intubation events and to assess current practice of intubation in critically ill patients. Design, Setting, and Participants: The International Observational Study to Understand the Impact and Best Practices of Airway Management in Critically Ill Patients (INTUBE) study was an international, multicenter, prospective cohort study involving consecutive critically ill patients undergoing tracheal intubation in the intensive care units (ICUs), emergency departments, and wards, from October 1, 2018, to July 31, 2019 (August 28, 2019, was the final follow-up) in a convenience sample of 197 sites from 29 countries across 5 continents. Exposures: Tracheal intubation. Main Outcomes and Measures: The primary outcome was the incidence of major adverse peri-intubation events defined as at least 1 of the following events occurring within 30 minutes from the start of the intubation procedure: cardiovascular instability (either: systolic pressure &lt;65 mm Hg at least once, &lt;90 mm Hg for &gt;30 minutes, new or increase need of vasopressors or fluid bolus &gt;15 mL/kg), severe hypoxemia (peripheral oxygen saturation &lt;80%) or cardiac arrest. The secondary outcomes included intensive care unit mortality. Results: Of 3659 patients screened, 2964 (median age, 63 years; interquartile range [IQR], 49-74 years; 62.6% men) from 197 sites across 5 continents were included. The main reason for intubation was respiratory failure in 52.3% of patients, followed by neurological impairment in 30.5%, and cardiovascular instability in 9.4%. Primary outcome data were available for all patients. Among the study patients, 45.2% experienced at least 1 major adverse peri-intubation event. The predominant event was cardiovascular instability, observed in 42.6% of all patients undergoing emergency intubation, followed by severe hypoxemia (9.3%) and cardiac arrest (3.1%). Overall ICU mortality was 32.8%. Conclusions and Relevance: In this observational study of intubation practices in critically ill patients from a convenience sample of 197 sites across 29 countries, major adverse peri-intubation events - in particular cardiovascular instability - were observed frequently