Extracellular vesicles from dental pulp mesenchymal stem cells modulate macrophage phenotype during acute and chronic cardiac inflammation in athymic nude rats with myocardial infarction.

BACKGROUND/AIMS: Extracellular vesicles (EVs) derived from dental pulp mesenchymal stem cells (DP-MSCs) are a promising therapeutic option for the treatment of myocardial ischemia. The aim of this study is to determine whether MSC-EVs could promote a pro-resolving environment in the heart by modulating macrophage populations. METHODS: EVs derived from three independent biopsies of DP-MSCs (MSC-EVs) were isolated by tangential flow-filtration and size exclusion chromatography and were characterized by omics analyses. Biological processes associated with these molecules were analyzed using String and GeneCodis platforms. The immunomodulatory capacity of MSC-EVs to polarize macrophages towards a pro-resolving or M2-like phenotype was assessed by evaluating surface markers, cytokine production, and efferocytosis. The therapeutic potential of MSC-EVs was evaluated in an acute myocardial infarction (AMI) model in nude rats. Infarct size and the distribution of macrophage populations in the infarct area were evaluated 7 and 21 days after intramyocardial injection of MSC-EVs. RESULTS: Lipidomic, proteomic, and miRNA-seq analysis of MSC-EVs revealed their association with biological processes involved in tissue regeneration and regulation of the immune system, among others. MSC-EVs promoted the differentiation of pro-inflammatory macrophages towards a pro-resolving phenotype, as evidenced by increased expression of M2 markers and decreased secretion of pro-inflammatory cytokines. Administration of MSC-EVs in rats with AMI limited the extent of the infarcted area at 7 and 21 days post-infarction. MSC-EV treatment also reduced the number of pro-inflammatory macrophages within the infarct area, promoting the resolution of inflammation. CONCLUSION: EVs derived from DP-MSCs exhibited similar characteristics at the omics level irrespective of the biopsy from which they were derived. All MSC-EVs exerted effective pro-resolving responses in a rat model of AMI, indicating their potential as therapeutic agents for the treatment of inflammation associated with AMI.

Trends in pediatric CNS tumors in Armenia: a multicenter retrospective study.

PURPOSE: Central nervous system (CNS) tumors are the most common solid malignancies in children worldwide, including in Armenia. The current study aims to analyze epidemiological data, treatment, and outcomes of children and young adults (≤25 years) with CNS tumors in Armenia during the last 26 years. METHODS: We collected data from pediatric and young adult patients treated in selected sites in Armenia from 1st January 1995 to 31st December 2020. Incidence by sex, age at diagnosis, time from first complaints to diagnosis, histopathology results, treatment strategies, complications, and overall survival (OS) rates were calculated. RESULTS: The multicenter data analysis revealed 149 patients with diagnosed primary CNS tumors over 26 years. Among them, 84 (56.4%) were male. The median age at diagnosis was 7 years (range, 3 months to 25 years), and the median time from the first complaints to diagnosis was 2 months (range, 1 week to 70 months). Medulloblastomas and other embryonal tumors (47), low-grade gliomas (32), and high-grade gliomas (22) were the most commonly diagnosed malignancies. Ependymomas, craniopharyngiomas, germ cell tumors, and other malignancies were observed in 22 patients. For 26 patients, no histopathological or radiological diagnosis was available. Follow-up information was available for 98 (65.8%) patients. The 5-year OS rate for the whole study group was 67.7%. CONCLUSION: Consistent with international data, embryonal tumors, and gliomas were the most commonly diagnosed CNS malignancies in Armenia. Multimodal treatment was often not available in Armenia during the study period, especially for early cases.

Reliable assessment of carbon black nanomaterial of a variety of cell culture media for in vitro toxicity assays by asymmetrical flow field-flow fractionation.

Carbon black nanomaterial (CB-NM), as an industrial product with a large number of applications, poses a high risk of exposure, and its impact on health needs to be assessed. The most common testing platform for engineered (E)NMs is in vitro toxicity assessment, which requires prior ENM dispersion, stabilization, and characterization in cell culture media. Here, asymmetric flow field-flow fractionation (AF4) coupled to UV-Vis and dynamic light scattering (DLS) detectors in series was used for the study of CB dispersions in cell culture media, optimizing instrumental variables and working conditions. It was possible to disperse CB in a non-ionic surfactant aqueous solution due to the steric effect provided by surfactant molecules attached on the CB surface which prevented agglomeration. The protection provided by the surfactant or by culture media alone was insufficient to ensure good dispersion stability needed for carrying out in vitro toxicity studies. On the other hand, cell culture media in combination with the surfactant improved dispersion stability considerably, enabling the generation of shorter particles and a more favourable zeta potential magnitude, leading to greater stability due to electrostatic repulsion. It was demonstrated that the presence of amino acids in the culture media improved the monodisperse nature and stability of the CB dispersions, and resulted in a turn towards more negative zeta potential values when the pH was above the amino acid isoelectric point (IEP). Culture media used in real cell culture scenarios were also tested, and in vitro toxicity assays were developed optimizing the compatible amount of surfactant.

Treating rare tumors with the assistance of the expert virtual consultation system: two cases of juvenile granulosa cell tumors.

BACKGROUND: The lack of internationally recognized guidelines for very rare tumors, such as juvenile granulosa cell tumors (JGCTs), which are nonepithelial, unusual ovarian tumors, is a challenge for pediatric oncologists, especially in developing countries with limited resources and experience in treating rare tumors. METHODS: We report clinical data of 2 girls with JGCTs treated at the Pediatric Cancer and Blood Disorders Center of Armenia with the assistance of the EXPeRT (European Cooperative Study Group for Pediatric Rare Tumors) international cooperation panel. CASE PRESENTATION: Two girls (16 and 15 years old) with JGCTs of the ovaries, stage Ic, underwent surgery and, with consultation through an online advisory board (http://vrt.cineca.it/), received 4 cycles of chemotherapy according to the PEI regimen (cisplatin, etoposide, ifosfamide). CONCLUSION: Very rare tumors, especially in advanced stages, have limited data and a low survival rate. International collaboration with the EXPeRT group is beneficial for physicians with limited experience and facilitates research in pediatric oncology.

Younger age and previous exposure to radiation therapy are correlated with the severity of chemotherapy-induced thrombocytopenia.

BACKGROUND: Chemotherapy-induced thrombocytopenia (CIT) is a significant complication of cancer therapy. Data on the optimal management approaches of this morbidity in children and young adults are still limited. AIM: The aim of the study is to estimate the frequency and severity of CIT and associated clinically significant bleeding in children and young adults with solid tumours and haematologic malignancies. METHODS: For this retrospective, hospital-based study, children (0-18 y) and young adults (19-40 y) with different types of solid tumours and haematologic malignancies who received chemotherapy at the Muratsan Hospital Complex of Yerevan State Medical University were identified from the patients' database and included in the study (overall 122 patients). Thrombocytopenia was defined as a decrease of platelet count below <100 × 109/L. For assessing bleeding, WHO scale had been used. RESULTS: Overall, the whole group of patients received 430 chemotherapy cycles. During 131 (31.6%) chemotherapy cycles, patients developed CIT. The study revealed a statistically significant inversely proportional correlation between the age and the severity of CIT. Another important finding of the study was that the patients, who previously were exposed to radiation therapy, were more likely to develop CIT, than those who have not received radiation therapy (68% and 28.7%, p = 0.001). From 430 cycles of chemotherapy, 31 (7.2%) cycles reported to have bleeding events. CONCLUSION: Our study showed that clinically significant thrombocytopenia and bleeding are quite rare among children and young adults. Younger age and previous exposure to radiation therapy are positively correlated with the severity of thrombocytopenia. Larger studies are needed to investigate these findings.

Denosumab treatment for progressive skull base giant cell tumor of bone in a 14 year old female - a case report and literature review.

BACKGROUND: Giant cell tumor of bone (GCT) is a rare primary bone tumor, which can metastasize and undergo malignant transformation. The standard treatment of GCT is surgery. In patients with unresectable or metastatic disease, additional therapeutic options are available. These include blocking of the receptor activator of NF-kappa B ligand (RANKL) signaling pathway, which plays a role in the pathogenesis of GCT of bone, via the anti-RANKL monoclonal antibody denosumab. CASE PRESENTATION: Herein we report on a female teenager who presented in a very poor clinical condition (cachexia, diplopia, strabismus, dysphonia with palsy of cranial nerves V, VI, VIII, IX, X, XI and XII) due to progressive disease, after incomplete resection and adjuvant radiotherapy, of a GCT which affected the cervical spine (C1 and C2) as well as the skull base; and who had an impressive clinical response to denosumab therapy. To the best of our knowledge, this is the youngest patient ever reported with a skull base tumor treated with denosumab. CONCLUSION: In situations when surgery can be postponed and local aggressiveness of the tumor does not urge for acute surgical intervention, upfront use of denosumab in order to reduce the tumor size might be considered. Principally, the goal of denosumab therapy is to reduce tumor size as much as possible, with the ultimate goal to make local surgery (or as in our case re-surgery) amenable. However, improvement in quality of life, as demonstrated in our patient, is also an important aspect of such targeted therapies.

Treating Adults with Hodgkin Lymphoma in the Developing World: a Hospital-Based Cohort Study from Armenia.

BACKGROUND: With advances in diagnostics and treatment approaches, patients with Hodgkin's lymphoma (HL) in developed countries can nowadays expect to have excellent outcomes. However, information about the characteristics and outcomes in the developing world is very scarce, and this is important given the fact that there are several reports about differences of disease characteristics depending on geographic location and the development level of the country. MATERIALS AND METHODS: In this retrospective study we assessed the features of 36 adult (≥18 years old) patients with HL and their diagnosis and treatment and outcomes in the Clinic of Chemotherapy of Muratsan University Hospital of Yerevan State Medical University, Armenia, between 2008- 2014. RESULTS: All patients had classic HL and among them 19 (53%) had nodular sclerosis subtype, 8 (22%) mixed cellularity and 9 (25%) lymphocyte-rich. 16 (44.5%) patients were at stage II, 13 (36%) stage III and 7 (19.5%) stage IV. Median follow-up time was 24.5 months (range 1-71 months) and during the whole follow- up period only two relapses (early) were documented and there were no deaths. Twenty-three (64%) patients received a BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) regimen, and 13 (36%) ABVD (doxorubicin, bleomycin, vinblastine and dacarbazine) regimen. A total of 25 (69.5%) patients received radiation in addition to chemotherapy. CONCLUSIONS: Although the number of patients involved in the study is small and the median follow-up time was just two years, this retrospective study shows that treatment of HL can be successfully organized in a resource-limited setting.