Reliability of B-line quantification by different-level observers and a software algorithm using point-of-care lung ultrasound.

Quantification of B-lines on lung ultrasonographs is operator-dependent and considered a semi-quantitative method. To avoid this variability, we designed a software algorithm for counting B-lines. We compared the number of B-lines obtained in real-time by observers with three different levels of experience and by the software algorithm, and analyzed intra-rater variability in terms of the estimated number of B-lines in two successive examinations. Forty mechanically ventilated adult (≥ 18 years) intensive care unit patients were included in this prospective study. All patients underwent two consecutive ultrasound examinations for B-lines detection by three human observers (OB1 = high, OB2 = medium, OB3 = low level of experience) and by the software (OBS). Ultrasound scans were obtained on the anterior right and left thoracic side along the midclavicular line, in the second and fourth intercostal space; B-lines counting for each position lasted 10 s. To assess intra-observer variability, a second ultrasound scan was obtained 15-30 min after the first scan. For all lung zones, the intraclass correlation for B-lines counting between OB1 and OB2 was 0.663; between OB1 and OB3, 0.559; and between OB1 and OBS, 0.710. OBS had a better concordance coefficient (0.752) between the first and the second measurements than did the human observers. Our results show that the software algorithm for B-lines counting is a potentially promising alternative when observers have little lung ultrasound experience.

Decrease of Perforin Expressing Lymphocytes after On-Pump Coronary Artery Bypass Grafting Surgery Irrespective of Carbohydrate Preoperative Oral Feeding.

BACKGROUND: Coronary artery bypass grafting (CABG) surgery continues to be the gold standard for treating the patients with coronary artery disease. CABG surgery can be performed on or off cardiopulmonary bypass, termed as on-pump or off-pump CABG, respectively. It has been shown that CABG surgery, preferably on-pump CABG surgery, leads to the changes of cell immunity during perioperative and early postoperative period. The mechanisms of regulation of the immune response in patients during and early after surgical revascularization are not fully understood. The aim of this study was to investigate the influence of carbohydrate preoperative oral feeding on frequency and perforin expression in peripheral blood lymphocytes in patients after on- or off-pump CABG surgery in early postoperative period. PATIENTS AND METHODS: In this prospective clinical study, 80 patients scheduled for CABG surgery were included in the study. The patients were randomly allocated into four groups (20 in each group): patients in Group 1 underwent on-pump CABG and did not receive carbohydrate preoperative oral feeding; patients in Group 2 underwent on-pump CABG and were preoperatively fed; patients in Group 3 underwent off-pump CABG and did not receive carbohydrate preoperative oral feeding; while patients in Group 4 underwent off-pump CABG and received carbohydrate preoperative oral feeding. Blood samples were collected immediately before (T1), 24 (T2) and 72 (T3) hours after the surgery. Peripheral blood mononuclear cells were isolated by gradient centrifugation and simultaneously labelled by antigens using fluorochrome-conjugated monoclonal antibodies. Frequency of T lymphocytes, NK and NKT cells, their subsets as well as their perforin expression were detected, and analyzed by flow cytometry. RESULTS: There was significant decrease in frequency of CD3+ and CD3+CD4+ cells, as well as perforin expressing CD3+CD8+ cells in patients who underwent on-pump CABG in comparison to patients who underwent off-pump CABG 24 hours after the surgery. Carbohydrate preoperative oral feeding did not effect changes in lymphocytes subpopulations and perforin expression at any time point. CONCLUSION: Decreases of CD3+ cells on account of CD3+CD4+ subsets, and perforin expressing cells on account of CD3+CD8+ perforin+ cells were found in patients who had undergone on-pump CABG, but not in patients who had undergone off-pump CABG surgery, irrespectively of carbohydrate preoperative oral feeding.

Severe Traumatic Brain Injury Induces Early Changes in the Physical Properties and Protein Composition of Intracranial Extracellular Vesicles.

Extracellular vesicles (EVs) are membranous nanostructures that can indicate undergoing processes in organs and thus help in diagnostics and prognostics. They are secreted by all cells, contained in body fluids, and able to transfer proteins, lipids and nucleic acids to distant cells. Intracranial EVs were shown to change their composition after severe traumatic brain injury (TBI) and therefore to have biomarker potential to evaluate brain events. Properties of intracranial EVs early after TBI, however, have not been characterized. Here, we assessed cerebrospinal fluid (CSF) up to seven days after isolated severe TBI for physical properties of EVs and their proteins associated with neuroregeneration. These findings were compared with healthy controls and correlated to patient outcome. The study included 17 patients with TBI and 18 healthy controls. EVs in TBI-CSF were visualized by electron microscopy and confirmed by immunoblotting for membrane associated Flotillin-1 and Flotillin-2. Using nanoparticle tracking analysis, we detected the highest range in EV concentration at day 1 after injury and significantly increased EV size at days 4-7. CSF concentrations of neuroregeneration associated proteins Flotillin-1, ADP-ribosylation Factor 6 (Arf6), and Ras-related protein Rab7a (Rab7a) were monitored by enzyme-linked immunosorbent assays. Flotillin-1 was detected solely in TBI-CSF in about one third of tested patients. Unfavorable outcomes included decreasing Arf6 concentrations and a delayed Rab7a concentration increase in CSF. CSF concentrations of Arf6 and Rab7a were negatively correlated. Our data suggest that the brain response within several days after severe TBI includes shedding of EVs associated with neuroplasticity. Extended studies with a larger number of participants and CSF collected at shorter intervals are necessary to further evaluate neuroregeneration biomarker potential of Rab7a, Arf6, and Flotillin-1.

Frequency and perforin expression of different lymphocyte subpopulations in patients with lower limb fracture and thoracic injury.

INTRODUCTION: Trauma with multiple injuries is associated with a high risk of complications, which may be related to excessive stimulation of inflammatory and anti-inflammatory responses. Although the effects of polytrauma on the immune response have been well established at the cellular and molecular levels, there is little information about the changes in the cytolytic potential of immunocompetent cells, including expression of cytotoxic molecules such as perforin. Therefore, the objective of the present study was to analyse and compare differences in the frequency and perforin expression of leukocyte subpopulations in the peripheral blood of patients with lower limb fracture, thoracic injury, and simultaneous lower limb fracture and thoracic injury. PATIENTS AND METHODS: Forty-five patients with trauma injury (15 patients with lower limb injury, 15 patients with thoracic injury, and 15 patients with simultaneous lower limb and thoracic injury) were included in the study. Peripheral blood of 15 sex- and age-matched healthy volunteers served as the control group. Peripheral blood samples were taken from all subjects included in the study and peripheral blood mononuclear cells were isolated by gradient centrifugation. The frequency of T lymphocytes, natural killer (NK) and NK T cells, and their subsets, as well as their perforin expression levels were simultaneously detected and analysed by flow cytometry. RESULTS: There was a statistically significant decrease in the frequency of T lymphocytes, NK and NK T cells as well as perforin expression in the patients with simultaneous lower limb and thoracic injury compared with the other two groups, with a predominantly marked decrease in NK and NK T cells. CONCLUSION: The decrease in the frequency and cytotoxic potential of peripheral blood lymphocytes is related to the severity of trauma injury, which can explain the underlying mechanism contributing to complication occurrence.