The preparation of autologous platelet and extracellular vesicle-rich plasma (PVRP) has been explored in many medical fields with the aim to benefit from its healing potential. In parallel, efforts are being invested to understand the function and dynamics of PVRP that is complex in its composition and interactions. Some clinical evidence reveals beneficial effects of PVRP, while some report that there were no effects. To optimize the preparation methods, functions and mechanisms of PVRP, its constituents should be better understood. With the intention to promote further studies of autologous therapeutic PVRP, we performed a review on some topics regarding PVRP composition, harvesting, assessment and preservation, and also on clinical experience following PVRP application in humans and animals. Besides the acknowledged actions of platelets, leukocytes and different molecules, we focus on extracellular vesicles that were found abundant in PVRP.

Tularemia is a zoonosis caused by the highly invasive bacterium Francisella tularensis. It is transmitted to humans by direct contact with infected animals or by vectors, such as ticks, mosquitos, and flies. Even though it is well-known as a tick-borne disease, it is usually not immediately recognised after a tick bite. In Slovenia, tularemia is rare, with 1–3 cases reported annually; however, the incidence seems to be increasing. Ulceroglandular tularemia is one of its most common forms, with cervical colliquative lymphadenopathy as a frequent manifestation. The diagnosis of tularemia largely relies on epidemiological information, clinical examination, imaging, and molecular studies. Physicians should consider this disease a differential diagnosis for a neck mass, especially after a tick bite, as its management significantly differs from that of other causes. Tularemia-associated lymphadenitis is treated with antibiotics and surgical drainage of the colliquated lymph nodes. Additionally, tularemia should be noted for its potential use in bioterrorism on behalf of the causative agents’ low infectious dose, possible aerosol formation, no effective vaccine at disposal, and the ability to produce severe disease. This article reviews the recent literature on tularemia and presents a case of an adult male with tick-borne cervical ulceroglandular tularemia.

Platelets are a natural source of signaling molecules, growth factors, cytokines and extracellular vesicles that modify the pericellular microenvironment in favor of tissue healing and regeneration. Autologous platelet-rich products, such as platelet-rich plasma are used in many fields of clinical medicine to benefit from these effects. Platelet-rich products are ideally used in more than a single application, but repetitive harvesting of concentrated platelets is time-consuming and impractical for patients and clinicians. In order to maximize the utility of priorly made products and create a supply of patients’ own preparations, investigations of appropriate storage of platelet products have emerged. Recent explorations of hypothermic preservation, such as cryopreservation or freeze-drying have shown positive results, providing an efficient possibility of platelet-rich product storage retaining their growth factor, cytokine and chemokine activity. Keywords: Platelet-rich plasma, Cryopreservation, Freeze-drying, Platelet storage, Cyto-kines, Growth factors, Healing