A Review of Key Regulators of Steady-State and Ineffective Erythropoiesis.

Erythropoiesis is initiated with the transformation of multipotent hematopoietic stem cells into committed erythroid progenitor cells in the erythroblastic islands of the bone marrow in adults. These cells undergo several stages of differentiation, including erythroblast formation, normoblast formation, and finally, the expulsion of the nucleus to form mature red blood cells. The erythropoietin (EPO) pathway, which is activated by hypoxia, induces stimulation of the erythroid progenitor cells and the promotion of their proliferation and survival as well as maturation and hemoglobin synthesis. The regulation of erythropoiesis is a complex and dynamic interaction of a myriad of factors, such as transcription factors (GATA-1, STAT5), cytokines (IL-3, IL-6, IL-11), iron metabolism and cell cycle regulators. Multiple microRNAs are involved in erythropoiesis, mediating cell growth and development, regulating oxidative stress, erythrocyte maturation and differentiation, hemoglobin synthesis, transferrin function and iron homeostasis. This review aims to explore the physiology of steady-state erythropoiesis and to outline key mechanisms involved in ineffective erythropoiesis linked to anemia, chronic inflammation, stress, and hematological malignancies. Studying aberrations in erythropoiesis in various diseases allows a more in-depth understanding of the heterogeneity within erythroid populations and the development of gene therapies to treat hematological disorders.

The Role of Vitamin D Deficiency in Children With Recurrent Wheezing-Clinical Significance.

Recurrent wheezing (RW) in infancy is one of the most frequent reasons for parents to consult health care providers and creates a significant global burden. Clinical course of RW is difficult to predict, also which infants will progress to asthma, since no valid biomarkers have been established. Identification of those infants with RW who are at risk of further recurrences and/or severe acute respiratory tract infection (ARTI) could help pediatricians to improve their therapeutic decisions. Increasing research interest is focused on the extra-skeletal actions of vitamin D (VD) and the clinical impact of VD insufficiency/deficiency. As VD deficiency could be a risk factor for causing RW in children, measurement of their serum level of 25-hydroxycholecalciferol [25(OH)D] is recommended. In the case of deficiency, VD administration is recommended in age-appropriate doses for at least 6 weeks, until achievement of normal blood 25(OH)D level, followed by supplementation as long as exposure to sun is inadequate. Higher doses of VD given in an attempt to prevent asthma development appear to be of no additional benefit. In children with severe ARTI, VD level is recommended to be assess.

Chondroprotective effects of pulsed shortwave therapy in rabbits with experimental osteoarthritis.

INTRODUCTION: Osteoarthritis (OA) represents a public health challenge since the pathogenic treatment, able to induce cartilage regeneration, still remains unknown. Ageing of the population and increasing OA prevalence have led to a lot of research, aiming to identify treatments acting on chondrocytes that play a determinant role in cartilage degeneration÷regeneration balance. Pulsed shortwave therapy (with the classical application form - Diapulse) is a physiotherapy method with anabolic effects demonstrated on nervous, conjunctive and vascular tissues, but its effects on OA cartilage are not known. AIM: Our aim was to demonstrate the effects of Diapulse on the cartilage in experimental induced OA. MATERIALS AND METHODS: Experimental OA was induced in 10 mature female rabbits by anterior cruciate ligament transection (ACLT). Ten weeks after ACLT, rabbits were randomized in a treatment group and a control group. Treatment group was exposed to Diapulse at a frequency of 27.12 MHz, pulse length of 65 µs, pulse frequency of 300 pulses÷s (300 Hz) for 10 minutes÷day. Control group was exposed to sham therapy. After treatment, rabbits were sacrificed and the cartilage was evaluated by histopathological examinations with Hematoxylin-Eosin (HE) staining and transmission electron microscopy (TEM). RESULTS: OA characteristic changes were found in both groups. In the treatment group, we found that Diapulse influenced the degenerative process in the OA cartilage by improving the chondrocyte viability and the capacity to maintain cellular matrix integrity and structure. CONCLUSIONS: Diapulse can be considered a disease modifying therapeutic procedure and could be a reliable option for treatment of OA patients.

Role of PD-L1/PD-1 in the immune response to respiratory viral infections.

Airway epithelial cells are the main cells infected by respiratory viruses including rhinoviruses and respiratory syncytial virus. Virus modulation of inhibitory molecule PD-L1 on epithelial cells may be important in limiting anti-viral effector CD8(+) T cell responses and, consequently, worsening acute virus-induced lung tissue damage.