No abstract

In order to prepare optimal platelet and extracellular vesicle (EV)-rich plasma for the treatment of chronic temporal bone inflammation, we studied effects of centrifugation parameters on redistribution of blood constituents in blood samples of 23 patients and 20 volunteers with no record of disease. Concentrations of blood cells and EVs were measured by flow cytometry. Sample content was inspected by scanning electron microscopy. A mathematical model was constructed to interpret the experimental results. The observed enrichment of plasma in platelets and EVs after a single spin of blood depended on the erythrocyte sedimentation rate, thereby indicating the presence of a flow of plasma that carried platelets and EVs in the direction opposite to settling of erythrocytes. Prolonged handling time correlated with the decrease of concentration of platelets and larger EVs in platelet and EV-rich plasma (PVRP), R = −0.538, p = 0.003, indicating cell fragmentation during the processing of samples. In further centrifugation of the obtained plasma, platelet and EV enrichment depended on the average distance of the sample from the centrifuge rotor axis. Based on the agreement of the model predictions with observations, we propose the centrifugation protocol optimal for platelet and EV enrichment and recovery in an individual sample, adjusted to the dimensions of the centrifuge rotor, volume of blood and erythrocyte sedimentation rate.

PurposeTo determine the efficacy of autologous platelet- and extracellular vesicle-rich plasma (PVRP) to treat chronic postoperative temporal bone cavity inflammation (CPTBCI) after exhausting surgical and standard conservative therapies.Materials and MethodsPatients were randomly allocated to treatment with PVRP (PVRP group) or standard conservative methods (control group) in a setting of four once-monthly checkups and subsequent follow-up. The treatment outcome was measured with the Chronic Otitis Media Questionnaire-12 (COMQ-12), CPTBCI focus surface area, and CPTBCI symptom-free time after the fourth checkup.ResultsEleven patients from each group completed the trial; 95% of patients suffered from chronically discharging mastoid cavity (the type of CPTBCI). Within four checkups, the COMQ-12 score decreased statistically significantly in the PVRP group (p < 0.001) but not in the control group (p = 0.339). The CPTBCI foci surface area decreased statistically significantly between the first and second checkups (p < 0.0005) but not between other checkups (p > 0.05) in the PVRP group. No statistically significant differences in CPTBCI foci surface area were detected between checkups in the control group (p = 0.152). Nine patients from the PVRP group and three patients from the control group were CPTBCI symptom-free at the fourth checkup. The median symptom-free time was 9.2 months (95% CI [7.4, 11.9]) in the PVRP group. Cumulatively, 49% of patients in the PVRP group remained CPTBCI symptom-free for 12.7 months after the fourth checkup.ConclusionAutologous PVRP represents a novel additional and successful treatment modality for a chronically discharging radical mastoid cavity when the surgical and standard conservative treatment methods have been exhausted.Trial Numberhttps://clinicaltrials.gov (NCT04281901).

No abstract

Extracellular vesicles (EVs) are gaining increasing amounts of attention due to their potential use in diagnostics and therapy, but the poor reproducibility of the studies that have been conducted on these structures hinders their breakthrough into routine practice. We believe that a better understanding of EVs stability and methods to control their integrity are the key to resolving this issue. In this work, erythrocyte EVs (hbEVs) were isolated by centrifugation from suspensions of human erythrocytes that had been aged in vitro. The isolate was characterised by scanning (SEM) and cryo-transmission electron microscopy (cryo-TEM), flow cytometry (FCM), dynamic/static light scattering (LS), protein electrophoresis, and UV-V spectrometry. The hbEVs were exposed to various conditions (pH (4–10), osmolarity (50–1000 mOsm/L), temperature (15–60 °C), and surfactant Triton X-100 (10–500 μM)). Their stability was evaluated by LS by considering the hydrodynamic radius (Rh), intensity of scattered light (I), and the shape parameter (ρ). The morphology of the hbEVs that had been stored in phosphate-buffered saline with citrate (PBS–citrate) at 4 °C remained consistent for more than 6 months. A change in the media properties (50–1000 mOsm/L, pH 4–10) had no significant effect on the Rh (=100–130 nm). At pH values below 6 and above 8, at temperatures above 45 °C, and in the presence of Triton X-100, hbEVs degradation was indicated by a decrease in I of more than 20%. Due to the simple preparation, homogeneous morphology, and stability of hbEVs under a wide range of conditions, they are considered to be a suitable option for EV reference material.

No abstract

It can be concluded that neither supervisors nor the level of communication between co-workers influence the frequency of adverse event reporting, while safety culture does influence it from an organizational point of view. The presumed factors only partly influence the number of submitted adverse event reports, thus other causes of under-reporting must be sought elsewhere.

Most surgical wounds heal by primary intention, that is, the wound is closed with sutures, clips, or glue. However, some surgical wounds are either left open to heal from the bottom up (“healing by secondary intention”) or break open partially or fully after primary closure. There is little basic knowledge about the occurrence and natural history of surgical wounds healing by secondary intention (SWHSI); therefore, the aim of this survey was to estimate the number of people with SWHSI in Slovenia, the nature of these wounds, and to investigate how they are managed. A multiservice, cross‐sectional survey was carried out over a 2‐week period in the city of Ljubljana, Slovenia (population 288,919). Healthcare professionals across health and social care settings completed one anonymised form for each patient with a SWHSI. Forms were completed for 110 patients. The point prevalence of SWHSI was 0.38 per 1,000 of the population (95% CI: 0.33–0.44). Patients’ mean age was 50.5 years. The majority of SWHSI were planned to heal by secondary intention before surgery (76/110, 69%). Of SWHSI, 83% (92/110) were treated with wound dressings, and 6% were treated with negative pressure wound therapy. Data were missing for 11 cases. This survey is the first to provide essential information about the extent, nature, and treatment of SWHSI in Slovenia. Furthermore, it is one of the latest of a very small number of studies to have contributed to knowledge about SWHSI globally. The results from the survey can be used for planning future research, health resources management, and policy development.