PRIMARY BENIGN ERYTHROCYTOSIS WITH HIGH ERYTHROPOIETIN LEVELS AND AN EARLY ERYTHROPOIETIN-SENSITIVE POPULATION IN THE PERIPHERAL-BLOOD

Primary erythrocytosis diagnosed in a 10-month-old female and followed for 12 years is described. The erythrocytosis was associated with an abnormally elevated set point of erythropoietin production in which the sensitivity fluctuated independently, but corresponded to the alterations in the oxygen-carrying capacity of the blood, when the hematocrit was lowered by phlebotomies. Extensive work for secondary erythrocytoses failed to demonstrate a recognizable cause for this abnormal erythropoietin production. Erythroid cell cultures from peripheral blood mononuclear cells showed the existence of at least two populations: one consistent with dramatic expansion of the erythron in keeping with enhanced sensitivity to endogenous erythropoietin, and the other consistent with the features of typical colonies derived from burst-forming units-erythroid (BFU-Es), seen in normal peripheral blood on days 12 to 14 of culture. The expanded population was characterized by the appearance of single colonies on days 4 to 6 and enormous response to the increasing amounts of erythropoietin, which enhanced their number, size, and maturation. The combination of clinical and in vitro data as well as the absence of any abnormality in the erythropoiesis of the parents and sibling suggest that the erythrocytosis in this child represents a new form with a benign course

Study of oncogenic transformation in ex vivo expanded mesenchymal cells, from paediatric bone marrow

OBJECTIVES: Mesenchymal stromal cells (MSCs) have attracted considerable interest in both the scientific and clinical fields. In order to obtain a sufficient cell number for application, their in vitro expansion is necessary, but during this process their characteristics may be altered and cells may acquire oncogenic properties. We have investigated properties of MSC that may be related to oncogenesis, a critical parameter that has to be evaluated prior to MSC clinical use. MATERIALS AND METHODS: We studied the expression of p53, p16, RB, H-RAS and human telomerase reverse transcriptase (hTERT) in MSCs from bone marrow of children diagnosed with idiopathic thrombocytopenic purpura (ITP) and autoimmune neutropenia. The same cells were seeded in soft agar to confirm their anchorage dependence and were karyotypically analysed. Finally, MSCs were subcutaneously transplanted into SCID mice and their ectopic osteogenic as well as tumorigenic potential was evaluated. RESULTS: We have shown that MSCs derived from bone marrow of children with ITP and autoimmune neutropenia do not undergo transformation, the cells expressed normal levels of p53, p16, RB and H-RAS. Expression of hTERT was undetectable, chromosome content remained stable, and their anchorage dependence was confirmed. In an in vivo model, when MSCs were subcutaneously transplanted into SCID mice, no tumorigenesis was observed. CONCLUSIONS: These findings suggest that MSCs from bone marrow of children do not have oncogenic properties and, therefore, represent validate candidates for applications in regenerative medicin

Skills of primary healthcare physicians in paediatric cardiac auscultation

Aim To evaluate the performance of primary healthcare physicians in paediatric cardiac auscultation and the impact of a multimedia-based teaching intervention. Methods A total of 106 primary healthcare physicians (77 paediatricians, 14 general practitioners and 15 medical graduates) attended four paediatric cardiac auscultation teaching courses based on virtual patients' presentation (digital phonocardiography). Their auscultatory performance was documented at the beginning of each course and at the end of two of the courses. Results Participants initially detected 73% of abnormal murmurs and 17% of additional sounds, while 22% of innocent murmurs were interpreted as abnormal. Overall cardiac auscultation performance, assessed by a combined auscultation score, was low and independent of training level (graduates: 39.5/trainees: 42.8/board certified: 42.6, p = 0.89) or specialty (paediatricians: 42.7/general practitioners: 43.1, p = 0.89). Multimedia-based teaching was associated with a significant improvement in abnormal murmur (92.5%) and additional sound (40%) detection (p < 0.001), while 25% of innocent murmurs were still interpreted as abnormal (p = 0.127). Conclusion Clinical skills of primary healthcare physicians in paediatric cardiac auscultation, independent of training level or specialty, still leave potential for improvement. Multimedia-based teaching interventions represent an effective means of improving paediatric cardiac auscultatory skills. © 2012 Foundation Acta Pædiatrica