Polarimetric imaging for the detection of synthetic models of SARS-CoV-2: A proof of concept.

Objective: To conduct a proof-of-concept study of the detection of two synthetic models of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using polarimetric imaging. Approach: Two SARS-CoV-2 models were prepared as engineered lentiviruses pseudotyped with the G protein of the vesicular stomatitis virus, and with the characteristic Spike protein of SARS-CoV-2. Samples were prepared in two biofluids (saline solution and artificial saliva), in four concentrations, and deposited as 5-µL droplets on a supporting plate. The angles of maximal degree of linear polarization (DLP) of light diffusely scattered from dry residues were determined using Mueller polarimetry from87 samples at 405 nm and 514 nm. A polarimetric camera was used for imaging several samples under 380-420 nm illumination at angles similar to those of maximal DLP. Per-pixel image analysis included quantification and combination of polarization feature descriptors in 475 samples. Main results: The angles (from sample surface) of maximal DLP were 3° for 405 nm and 6° for 514 nm. Similar viral particles that differed only in the characteristic spike protein of the SARS-CoV-2, their corresponding negative controls, fluids, and the sample holder were discerned at 10-degree and 15-degree configurations. Significance: Polarimetric imaging in the visible spectrum may help improve fast, non-contact detection and identification of viral particles, and/or other microbes such as tuberculosis, in multiple dry fluid samples simultaneously, particularly when combined with other imaging modalities. Further analysis including realistic concentrations of real SARS-CoV-2 viral particles in relevant human fluids is required. Polarimetric imaging under visible light may contribute to a fast, cost-effective screening of SARS-CoV-2 and other pathogens when combined with other imaging modalities.

Prognostic and diagnostic value of eosinopenia, C-reactive protein, procalcitonin, and circulating cell-free DNA in critically ill patients admitted with suspicion of sepsis.

INTRODUCTION: The aims of this study were to assess the reliability of circulating cell-free DNA (cf-DNA) concentrations, compared with C-reactive protein (CRP), procalcitonin (PCT) and eosinophil count, in the diagnosis of infections in patients with systemic inflammatory response syndrome (SIRS) and their prognostic values in a cohort of critically ill patients. METHODS: We conducted a prospective cohort study in a medical-surgical intensive care unit of a university hospital. Eosinophil count and concentrations of cf-DNA, CRP, and PCT were measured in patients who fulfilled SIRS criteria at admission to the intensive care unit (ICU) and a second determination 24 hours later. DNA levels were determined by a PCR method using primers for the human beta-haemoglobin gene. RESULTS: One hundred and sixty consecutive patients were included: 43 SIRS without sepsis and 117 with sepsis. Levels of CRP and PCT, but not cf-DNA or eosinophil count, were significantly higher in patients with sepsis than in SIRS-no sepsis group on days 1 and 2. PCT on day 1 achieves the best area under the curve (AUC) for sepsis diagnosis (0.87; 95% confidence interval = 0.81-0.94). Levels of cf-DNA do not predict outcome and the accuracy of these biomarkers for mortality prediction was lower than that shown by APACHE II score. PCT decreases significantly from day 1 to day 2 in survivors in the entire cohort and in patients with sepsis without significant changes in the other biomarkers. CONCLUSIONS: Our data do not support the clinical utility of cf-DNA measurement in critical care patients with SIRS. PCT is of value especially for infection identification in patients with SIRS at admission to the ICU.

Genetic profile in patients with complicated acute aortic syndrome: the GEN-AOR study.

INTRODUCTION AND OBJECTIVES: Genetic testing is becoming increasingly important for diagnosis and personalized treatments in aortopathies. Here, we aimed to genetically diagnose a group of acute aortic syndrome (AAS) patients consecutively admitted to an intensive care unit and to explore the clinical usefulness of AAS-associated variants during treatment decision-making and family traceability. METHODS: We applied targeted next-generation sequencing, covering 42 aortic diseases genes in AAS patients with no signs consistent with syndromic conditions. Detected variants were segregated by Sanger sequencing in available family members. Demographic features, risk factors and clinical symptoms were statistically analyzed by Fisher or Fisher-Freeman-Halton Exact tests, to assess their relationship with genetic results. RESULTS: Analysis of next-generation sequencing data in 73 AAS patients led to the detection of 34 heterozygous candidate variants in 14 different genes in 32 patients. Family screening was performed in 31 relatives belonging to 9 families. We found 13 relatives harboring the family variant, of which 10 showed a genotype compatible with the occurrence of AAS. Statistical tests revealed that the factors associated with a positive genetic diagnosis were the absence of hypertension, lower age, family history of AAS and absence of pain. CONCLUSIONS: Our findings broaden the spectrum of the genetic background for AAS. In addition, both index patients and studied relatives benefited from the results obtained, establishing the most appropriate level of surveillance for each group. Finally, this strategy could be reinforced by the use of stastistically significant clinical features as a predictive tool for the hereditary character of AAS. CLINICALTRIALS: gov (Identifier: NCT04751058).

Optical imaging spectroscopy for rapid, primary screening of SARS-CoV-2: a proof of concept.

Effective testing is essential to control the coronavirus disease 2019 (COVID-19) transmission. Here we report a-proof-of-concept study on hyperspectral image analysis in the visible and near-infrared range for primary screening at the point-of-care of SARS-CoV-2. We apply spectral feature descriptors, partial least square-discriminant analysis, and artificial intelligence to extract information from optical diffuse reflectance measurements from 5 µL fluid samples at pixel, droplet, and patient levels. We discern preparations of engineered lentiviral particles pseudotyped with the spike protein of the SARS-CoV-2 from those with the G protein of the vesicular stomatitis virus in saline solution and artificial saliva. We report a quantitative analysis of 72 samples of nasopharyngeal exudate in a range of SARS-CoV-2 viral loads, and a descriptive study of another 32 fresh human saliva samples. Sensitivity for classification of exudates was 100% with peak specificity of 87.5% for discernment from PCR-negative but symptomatic cases. Proposed technology is reagent-free, fast, and scalable, and could substantially reduce the number of molecular tests currently required for COVID-19 mass screening strategies even in resource-limited settings.

Hyperspectral image processing for the identification and quantification of lentiviral particles in fluid samples.

Optical spectroscopic techniques have been commonly used to detect the presence of biofilm-forming pathogens (bacteria and fungi) in the agro-food industry. Recently, near-infrared (NIR) spectroscopy revealed that it is also possible to detect the presence of viruses in animal and vegetal tissues. Here we report a platform based on visible and NIR (VNIR) hyperspectral imaging for non-contact, reagent free detection and quantification of laboratory-engineered viral particles in fluid samples (liquid droplets and dry residue) using both partial least square-discriminant analysis and artificial feed-forward neural networks. The detection was successfully achieved in preparations of phosphate buffered solution and artificial saliva, with an equivalent pixel volume of 4 nL and lowest concentration of 800 TU·[Formula: see text]L-1. This method constitutes an innovative approach that could be potentially used at point of care for rapid mass screening of viral infectious diseases and monitoring of the SARS-CoV-2 pandemic.

Impact of age of transfused blood on cerebral oxygenation in male patients with severe traumatic brain injury.

OBJECTIVE: Prolonged erythrocyte storage time might reduce the efficacy of transfusion. In this study, the effects of transfusion of erythrocytes with four different storage periods (<10 days, n = 18; 10-14 days, n = 15; 15-19 days, n = 17; and >19 days, n = 16 patients) on brain tissue oxygen tension (PtiO2) in stable male patients with severe traumatic brain injury were investigated during a 24-hr follow-up period. DESIGN: Prospective, observational study. SETTING: Neurotrauma critical care unit of a university hospital. PATIENTS: Sixty-six male, nonbleeding, hemodynamically stable anemic patients (hemoglobin <95 g/L) with Glasgow Coma Scale score <9. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: PtiO2, cerebral perfusion pressure, mean arterial pressure, intracranial pressure, peripheral oxygen saturation, CO2 pressure at the end of expiration, and intracerebral temperature were recorded in all patients at baseline, immediately after the completion of transfusion, and 1, 2, 3, 4, 5, 6, 12, and 24 hrs posttransfusion. All four groups were homogeneous with respect to multiple baseline variables, except for storage time of transfused erythrocytes (p < .0001). There was a significant short-lasting (3-4 hrs) increase in PtiO2 values after transfusion of erythrocytes stored for <10 days, 10-14 days, or 15-19 days, compared with those at baseline. In contrast, no significant changes in PtiO2 were observed after transfusion of erythrocytes stored >19 days. CONCLUSIONS: Transfusion of erythrocytes increased cerebral oxygenation in patients with severe traumatic brain injury, except in those transfused with erythrocytes stored >19 days.

Red blood cell transfusion in non-bleeding critically ill patients with moderate anemia: is there a benefit?

PURPOSE: This study was undertaken to investigate the efficacy of red blood cell transfusion (RBCT) at reversing the deleterious effects of moderate anemia in critically ill, non-bleeding patients. METHODS: This was a retrospective, pair-matched (ratio 1:1) cohort study. Non-bleeding critically ill patients with moderate anemia (nadir hemoglobin level between 70 and 95 g/l), admitted to the ICU over a 27-month period, were included. Anemic patients were included upon meeting five matching criteria of having the same nadir hemoglobin (±5 g/l), APACHE II score (±5), SOFA score (±2), admission diagnostic group, and age (±5 years). Outcome events occurring over the whole ICU stay and after RBCT were collected. After hospital discharge, all patients had a 2-year follow-up period. RESULTS: Two hundred fourteen non-transfused anemic patients (NTAPs) were successfully matched with 214 transfused anemic patients (TAPs). In addition to the matching criteria, at baseline, both groups were homogenous with respect to multiple comorbidities. Compared with TAPs, NTAPs showed significantly lower rates of hospital mortality (21 vs.13 %, respectively; p < 0.05) and ICU re-admission (7.4 vs. 1.9 %, respectively; p < 0.05). Additionally, NTAPs had significantly lower rates of nosocomial infection (12.9 vs. 6.7 %, respectively; p < 0.05) and acute kidney injury (24.8 vs. 16.7 %, respectively; p < 0.05). Similar results were obtained in subgroup analysis where only more anemic patients (68 matched pairs) or patients with cardiovascular comorbidities (63 matched pairs) were considered. CONCLUSIONS: RBCT does not improve the clinical outcome in non-bleeding critically ill patients with moderate anemia.

Efficacy of the prothrombin complex concentrate prothromplex in patients requiring urgent reversal of vitamin K antagonists or presenting with uncontrolled bleeding: a retrospective, single center study.

The objective of the present study was to investigate the efficacy of a four-factor prothrombin complex concentrate (Prothromplex, PTX) in shortening prolonged international normalized ratio or controlling life-threatening bleeding. The study was a retrospective single-centre study that included 142 patients treated with PTX and allocated in three groups: patients on vitamin K antagonists (VKA) (acenocumarol) and undergoing invasive procedure or presenting with severe bleeding (n = 76), patients treated with VKA presenting with intracranial haemorrhage (n = 22), and patients not on VKA and presenting with uncontrolled bleeding (n = 44). The primary outcome variable was international normalized ratio (INR) return to the norm after PTX infusion. Secondary outcome variables included bleeding control and reduction of transfusion rate. Overall, patients received a median of 1200 IU (≈15 IU/kg) of PTX, and INR decreased from 4 ±â€Š3 to 1.7 ±â€Š1.2 (P < 0.01) in all groups, although it remained at least 1.4 in 38% of patients (29.3% among patients receiving 25 IU/kg vs. 42.6% among those receiving 15 IU/kg; P < 0.05). Patients with initial INR at least 4 benefited the most from treatment. After PTX administration, there was a significant reduction in both transfused blood components units (P < 0.01) and estimated blood loss volume (from 1500 ±â€Š1500 to 200 ±â€Š100 ml; P < 0.01), and only one episode of deep venous thrombosis was observed. Administration of fixed doses of PTX shortened prolonged international normalized ratio and improved life-threatening bleeding in patients with or without VKA therapy. Higher dose attained a more adequate post-infusion INR.

[Toxic megacolon and jejunal perforation due to cytomegalovirus]. / Megacolon tóxico y perforación yeyunal por citomegalovirus.

Cytomegalovirus (CMV) infection is a frequent disease in immunocompromised patients and can affect the gastrointestinal tract in 50% of patients, giving rise to colitis due to CMV. However, a perforated jejunum is not frequent. We present the case of an immunocompromised patient who was diagnosed with colitis due to CMV infection after bowel perforation. Outcome was favorable after surgery and antiviral treatment.