Summary The risk profile of childhood leukaemia in Greece was studied through a case-control investigation that included all 153 incident cases of the disease, ascertained throughout the country during 1993 and 1994, and two hospital controls for every case matched for gender, age and place of residence. The data were analysed using conditional logistic regression and the associations are expressed in terms of adjusted odds ratios (OR) and their 95% confidence intervals. Cases were born to mothers of a higher standard education, the OR for an increment of four schooling years being 1.48 (1.17-1.87) and had higher birth weight, the OR for an increment of 500 g being 1.36 (1.04-1.77). Pet ownership and birth after a pregnancy with anaemia were associated with increased risk, the ORs being 2.18 (1.14-4.16) and 2.60 (1.39-4.86) respectively. From the frequency analyses, indicative inverse associations were found with birth order, household crowding and previous hospitalization with allergic diseases, whereas indicative positive associations were found with diabetes mellitus during pregnancy and with neonatal jaundice. Substantial or significant elevations were not found with respect to maternal smoking and coffee drinking during pregnancy, diagnostic radiography and ultrasonographic examinations or blood transfusions. A significant inverse association with maternal consumption of alcohol could be due to multiple comparisons, but a detrimental effect can probably be excluded. A non-significant positive association with total shots of viral vaccinations and a weak non-significant inverse association with breast feeding were also found. We interpret the findings of this study as being compatible with acute childhood leukaemia being linked with delayed development of herd immunity to fairly common infectious agents, in conjunction with accelerated perinatal and early post-natal growth.

Haemoglobinopathies are the most common hereditary disorders in Greece. Although there is a successful national prevention program, established 35 years ago, there is lack of an official registry and collection of epidemiological data for haemoglobinopathies. This paper reports the results of the first National Registry for Haemoglobinopathies in Greece (NRHG), recently organized by the Greek Society of Haematology. NRHG records all patients affected by thalassaemia major (TM), thalassaemia intermedia (TI), "H" Haemoglobinopathy (HH) and sickle cell disease (SCD). Moreover, data about the annual rate of new affected births along with deaths, between 2000 and 2010, are reported. A total of 4,506 patients are registered all over the country while the number of affected newborns was significantly decreased during the last 3 years. Main causes for still having affected births are: (1) lack of medical care due to financial reasons or low educational level; (2) unawareness of time limitations for prenatal diagnosis (PD); due either to obstetricians' malpractice or to delayed demand of medical care of couples at risk; and (3) religious, social or bioethical reasons. Cardiac and liver disorders consist main causes for deaths while life expectancy of patients lengthened after 2005 (p < 0.01). The NRHG of patients affected by haemoglobinopathies in Greece provides useful data about the haemoglobinopathies in the Greek population and confirms the efficacy of the National Thalassaemia Prevention Program on impressively decreasing the incidence of TM and sickle cell syndromes.

There has been no documented increase in childhood leukaemia following the Chernobyl accident. However, different forms of childhood leukaemia may not be equally susceptible to radiation carcinogenesis. Infant leukaemia is a distinct form associated with a specific genetic abnormality. Outside the former Soviet Union, contamination resulting from the Chernobyl accident has been highest in Greece and Austria and high also in the Scandinavian countries. All childhood leukaemia cases diagnosed throughout Greece since 1 January 1980 have been recorded. Here we report that infants exposed in utero to ionizing radiation from the Chernobyl accident had 2.6 times the incidence of leukaemia compared to unexposed children (95% confidence interval, 1.4 to 5.1; P approximately 0.003), and those born to mothers residing in regions with high radioactive fallout were at higher risk of developing infant leukaemia. No significant difference in leukaemia incidence was found among children aged 12 to 47 months. Preconceptional irradiation had no demonstrable effect on leukaemia risk at any of the studied age groups.

Stem cells are the self-renewing progenitors of several body tissues and are classified according to their origin and their ability to differentiate. Current research focuses on the potential uses of stem cells in medicine and how they can provide effective treatment for a range of diseases. This approach has resulted in the field of medical practice called regenerative medicine. To attain the promises of regenerative medicine, it is necessary to fully understand the biology and properties of stem cells, achieve their successful differentiation into functional tissues, overcome the barriers related to immune responses after administration, and assess any oncogenic properties that limit their use. The availability of human stem cells not only raises hope for cell replacement therapies, but also provides a system for understanding the mechanisms of embryonic development and disease progression. Nevertheless, it raises ethical concerns that need to be addressed before the use of stem cells in clinical practice.