1. Patients treated for idiopathic nephrotic syndrome in the past should undergo regular laboratory tests of atherosclerosis risk factors, including not only cholesterol and its fractions, but also ApoA1, ApoB and HCY. 2. It is necessary to continue systematic check-ups of the intima-media thickness of the carotid arteries among young patients with anamnesis of INS, especially among patients who suffered from numerous relapses of this disease.

Purpose To evaluate the extent to which the population of Polish preadolescents is vitamin D deficient and to assess seasonal variations in vitamin D status. Participants and methods A total of 720 healthy children aged 9-13 years (409 girls, 311 boys) residing in 6 representative geographical locations in Poland were studied. A parental-assisted questionnaire provided data on nutritional habits, vitamin D supplements and sun exposure. Serum concentration of 25-hydroxyvitamin was determined twice, after the winter in March and after the summer in October. Results In March, vitamin D deficiency (25-50 nmol/L) was found in 64%, and severe deficiency (< 25 nmol/L) in 20.2% of children. In October, the deficiency and severe deficiency were still noticed in 25.9 and 0.1% of children, respectively. The mean serum concentration of 25-OHD was 52% higher in October (55.4 ± 14.0 nmol/L) than in March (36.4 ± 13.5 nmol/L), (p < 0.01). In children with 25-OHD < 50 nmol/L in March, their 25-OHD concentration increased by 64% through March to October (32.5 ± 8.2 vs. 53.2 ± 7.9 nmol/L, p < 0.01). An association was found between 25-OHD concentration and regular consumption of vitamin D supplements, cod-liver oil and fish. Conclusions The majority of preadolescent Polish boys and girls show vitamin D deficiency after the winter period, although a distinct amelioration over summertime is found in this age group. There is a need to implement effective prevention and intervention strategies in the management of vitamin D deficiency among schoolchildren in Poland, with the supplementation throughout the entire year.

Mesenchymal chondrosarcoma (MC) is an infrequent, highly malignant neoplasm of the soft tissues and bone. It is very rare in the pediatric age group, especially in the intraspinal location. Only 24 cases have been reported to date. The authors present a case of a 14-year-old boy with an intraspinal MC who died of the disease 50 months from the initial diagnosis and after the third local recurrence. The patient was treated with a combination of chemotherapy, radiotherapy, and surgery. The authors review the clinical presentation, diagnostics, and the efficacy of treatment of pediatric patients with MC reported in the literature from 1978 to 2010.