2,2-Diphenyl-1-picrylhydrazyl (DPPH
*
) radical scavenging, the most commonly used antioxidant method with more than seventeen thousand articles cited, is very practical; however, as with most ...assays, it has the major disadvantage of dependence on a spectrophotometer. To overcome this drawback, the colorimetric determination of the antioxidant activity using a scanner and freely available Image J software was developed. In this new method, the mixtures of solutions of DPPH
*
and standard antioxidants or extracts of common medicinal herbs were dropped onto TLC plates, after an incubation period. The spot images were evaluated with Image J software to determine CSC
50
values, the sample concentrations providing 50% colour reduction, which were very similar with the SC
50
values obtained with spectrophotometric method. The advantages of the new method are the use of lower amounts of reagents and solvents, no need for costly spectrophotometers, and thus significantly lowered costs, and convenient implementation in any environment and situation.
Cynarin is a derivative of hydroxycinnamic acid and it has biologically active functional groups constituent of some plants and food. We elucidated the antioxidant activity of cynarin by using ...different in vitro condition bioanalytical antioxidant assays like DMPD
*+
, ABTS
*+
,
, DPPH
*
and H
2
O
2
scavenging effects, the total antioxidant influence, reducing capabilities, Fe
2+
chelating and anticholinergic activities. Cynarin demonstrated 87.72% inhibition of linoleic acid lipid peroxidation at 30 µg/mL concentration. Conversely, some standard antioxidants like trolox, α-tocopherol, butylated hydroxytoluene (BHT), and butylated hydroxyanisole (BHA) exhibited inhibitions of 90.32, 75.26, 97.61, 87.30%, and opponent peroxidation of linoleic acid emulsion at the identical concentration, seriatim. Also, cynarin exhibited effective DMPD
*+
, ABTS
*+
,
, DPPH
*
, and H
2
O
2
scavenging effects, reducing capabilities and Fe
2+
chelating effects. On the contrary, IC
50
and K
i
parameters of cynarin for acetylcholinesterase enzyme inhibition were determined as 243.67 nM (r
2
: 0.9444) and 39.34 ± 13.88 nM, respectively. This study clearly showed that cynarin had marked antioxidant, anticholinergic, reducing ability, radical-scavenging, and metal-binding activities.
Background
Mortality in critically ill patients with coronavirus disease 2019 (COVID‐19) is high, therefore, it is essential to evaluate the independent effect of new‐onset atrial fibrillation (NOAF) ...on mortality in patients with COVID‐19. We aimed to determine the incidence, risk factors, and outcomes of NOAF in a cohort of critically ill patients with COVID‐19.
Methods
We conducted a retrospective study on patients admitted to the intensive care unit (ICU) with a diagnosis of COVID‐19. NOAF was defined as atrial fibrillation that was detected after diagnosis of COVID‐19 without a prior history. The primary outcome of the study was the effect of NOAF on mortality in critically ill COVID‐19 patients.
Results
NOAF incidence was 14.9% (n = 37), and 78% of patients (n = 29) were men in NOAF positive group. Median age of the NOAF group was 79.0 (interquartile range, 71.5‐84.0). Hospital mortality was higher in the NOAF group (87% vs 67%, respectively, P = .019). However, in multivariate analysis, NOAF was not an independent risk factor for hospital mortality (OR 1.42, 95% CI 0.40‐5.09, P = .582).
Conclusions
The incidence of NOAF was 14.9% in critically ill COVID‐19 patients. Hospital mortality was higher in the NOAF group. However, NOAF was not an independent risk factor for hospital mortality in patients with COVID‐19.
The incidence of NOAF is high in critically ill COVID‐19 patients. Hospital mortality is high in severe COVID‐19 patients with NOAF. Patients with NOAF are older and have co‐existing comorbidities.
Pleural fluid pH measurement is recommended for tube thoracostomy decisions in complicated parapneumonic pleural effusions. However, pleural fluid pH may be affected by blood pH in critically ill ...patients with common systemic acid-base disorders. We aimed to investigate the use of pleural fluid lactate to distinguish culture-positive parapneumonic effusions from other pleural effusions.
This prospective observational study included 121 eligible patients (51 female and 70 male). All patients with pleural effusion who underwent thoracentesis were assessed. Pleural fluid lactate was measured by a blood gas analyzer.
Of the 121 patients, 30 (24.8%) were transudate and 91 (75.2%) were exudate. Of the 91 patients with exudative pleural effusion, 61 were diagnosed as culture-negative parapneumonic, 13 as culture-positive parapneumonic, 9 as malignant, and 8 as other exudative effusion. There was a strong positive linear association between serum pH and pleural fluid pH (R = 0.77, P < .001). The post hoc tests for pleural fluid lactate revealed there was a significant difference between culture-positive parapneumonic versus culture-negative parapneumonic groups (P = .004), culture-positive parapneumonic versus transudative effusion groups (P < .001), culture-negative parapneumonic versus transudative effusion groups (P = .008) and lastly; malignant effusion versus transudative effusion groups (P = .001). Receiver operating characteristics curve analysis for culture-positive parapneumonic indicated a cutoff of 4.55 mmol/L for pleural fluid lactate to have a sensitivity of 76.9% and a specificity of 84.3% (positive predictive value: 37%, negative predictive value: 96.8%).
A cutoff of 4.55 mmol/L of pleural fluid lactate can be used as a useful tool to distinguish culture-positive parapneumonic effusions from other effusions in critically ill patients.
Coronavirus disease 2019 (COVID-19) can cause acute respiratory distress syndrome (ARDS). Invasive mechanical ventilation (IMV) support and prone positioning are essential treatments for severe ...COVID-19 ARDS. We aimed to determine the combined effect of prone position and airway pressure release ventilation (APRV) modes on oxygen improvement in mechanically-ventilated patients with COVID-19.
This prospective observational study included 40 eligible patients (13 female, 27 male). Of 40 patients, 23 (57.5%) were ventilated with APRV and 17 (42.5%) were ventilated with controlled modes. A prone position was applied when the PaO
/FiO
ratio <150 mmHg despite IMV in COVID-19 ARDS. The numbers of patients who completed the first, second, and third prone were 40, 25, and 15, respectively. Incident barotrauma events were diagnosed by both clinical findings and radiological images.
After the second prone, the PaO
/FiO
ratio of the APRV group was higher compared to the PaO
/FiO
ratio of the control group 189 (150-237) vs. 127 (100-146) mmHg, respectively, (
=0.025). Similarly, after the third prone, the PaO
/FiO
ratio of the APRV group was higher compared to the PaO
/FiO
ratio of the control group 194 (132-263) vs. 83 (71-136) mmHg, respectively, (
=0.021). Barotrauma events were detected in 13.0% of the patients in the APRV group and 11.8% of the patients in the control group (
=1000). The 28-day mortality was not different in the APRV group than in the control group (73.9% vs. 70.6%, respectively,
=1000).
Using the APRV mode during prone positioning improves oxygenation, especially in the second and third prone positions, without increasing the risk of barotrauma. However, no benefit on mortality was detected.
The prediction of high-flow nasal oxygen (HFNO) failure in patients with coronavirus disease-2019 (COVID-19) having acute respiratory failure (ARF) may prevent delayed intubation and decrease ...mortality.
To define the related risk factors to HFNO failure and hospital mortality.
Retrospective cohort study.
To this study, 85 critically ill patients (≥18 years) with COVID-19 related acute kidney injury who were treated with HFNO were enrolled. Treatment success was defined as the de-escalation of the oxygenation support to the conventional oxygen therapies. HFNO therapy failure was determined as the need for invasive mechanical ventilation or death. The patients were divided into HFNO-failure (HFNO-F) and HFNO-success (HFNO-S) groups. Electronic medical records and laboratory data were screened for all patients. Respiratory rate oxygenation (ROX) index on the first hour and chest computed tomography (CT) severity score were calculated. Factors related to HFNO therapy failure and mortality were defined.
This study assessed 85 patients (median age 67 years, 69.4% male) who were divided into two groups as HFNO success (n = 33) and HFNO failure (n = 52). The respiratory rate oxygenation (ROX) was measured at 1 hour and the computed tomography (CT) score indicated HFNO failure and intubation, with an area under the receiver operating characteristic of 0.695 for the ROX index and 0.628 for the CT score. A ROX index of <3.81 and a CT score of >15 in the first hour of therapy were the predictors of HFNO failure and intubation. Age, Acute Physiology and Chronic Health Evaluation II score, arterial blood gas findings "(i.e., partial pressure of oxygen PaO
, PaO
fraction of inspired oxygen/SO
oxygen saturation ratio)", and D-dimer levels were also associated with HFNO failure; however, based on logistic regression analysis, a calculated ROX on the first hour of therapy of <3.81 (odds ratio OR = 4.78, 95% confidence interval CI = 1.75-13.02,
= 0.001) and a chest CT score of >15 (OR = 2.83, 95% CI = 1.01-7.88,
= <0.001) were the only independent risk factors. In logistic regression analysis, a ROX calculated on the first hour of therapy of <3.81 (OR = 4.78, 95% CI = 1.75-13.02,
= 0.001) and a chest CT score of >15 (OR 2.83, 95% CI = 1.01-7.88,
= <0.001) were the independent risk factors for the HFNO failure. The intensive care unit and hospital mortality rates were 80.2% and 82.7%, respectively, in the HFNO failure group.
The early prediction of HFNO therapy failure is essential considering the high mortality rate in patients with HFNO therapy failure. Using the ROX index and the chest CT severity score combined with the other clinical parameters may reduce mortality. Additionally, multi-centre observational studies are needed to define the predictive value of ROX and chest CT score not only for COVID-19 but also other causes of ARF.
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