Kamer Uysal

Platelet activation in congenital heart diseases

The research presented here investigated platelet activation in cyanotic and acyanotic congenital heart diseases (CHD). Children with cyanotic CHD are prone to both thrombosis and hemorrhage. However, patients with acyanotic CHD may also have a mild bleeding disorder. The platelet activation in CHD was investigated in support of a hypothesis that platelet activation may play a role in the hemostatic abnormalities reported in these patients. Platelet activation was determined by using flow cytometry with anti‐CD62 monoclonal antibody (mAb), which has been shown to be a specific marker of platelet activation. Thirteen children with cyanotic CHD, 33 children with acyanotic CHD and 17 healthy children serving as controls were studied. Platelet activation was significantly higher in the cyanotic group and also in the acyanotic group compared with the healthy children (P = 0.0000 and P = 0.019, respectively). In the cyanotic group, platelet activation showed a direct correlation with arterial O2 saturation (SaO2) (P = 0.014). There was no correlation between platelet activation and erythrocyte related parameters in either group. Platelet activation occurs in CHD, particularly in patients with cyanotic CHD (even in patients with no evidence of clinical thrombosis) and it may play a role in the pathogenesis of thrombotic disorders seen in these patients.

Experience of the Izmir Pediatric Oncology Group on Neuroblastoma: IPOG-NBL-92 Protocol

This multicentric study aimed to bring neuroblastoma patients together under IPOG-NBL-92 protocol and evaluate the results within the period between 1992 and 2001 in Izmir. Sixty-seven neuroblastoma patients from 4 pediatric oncology centers in Izmir were included in the study. IPOG-NBL-92 protocol modified from German Pediatric Oncology (GPO)-NB-90 protocol was applied: Patients in stage 1 received only surgery, while surgery plus 4 chemotherapy courses (cisplatin, vincristine, ifosfamide) were given in stage 2 and surgery plus 6 chemotherapy courses (cisplatin, vincristine, ifosfamide, epirubicin, cyclophosphamide) were given in stages 3 and 4 patients. In patients who were kept in complete remission (CR), a maintenance therapy of one year was applied. Radiotherapy was given to the primary site following induction chemotherapy plus surgery in stages 3 and 4 patients with partial remission (PR). The stages of the patients were as follows: 5% in stage 1, 39% in stage 3, 49% in stage 4, and 7% in stage 4S. Primary tumor site was abdomen in 88% of cases. CR rates were as 100% in stage 1, 76% in stage 3, 35% in stage 4, and 75% in stage 4S. Relapse was observed in 32% of patients in a median of 19 months. The median follow-up time for survivors was 33 (17-102) months. Five-year OS rate was 31% and the EFS rate was 30% in all patients. Five-year overall and event-free survival rates were 63 and 30% in stage 3, but 6 and 5%, respectively, in stage 4 patients. Univariate analysis established that the age, stage, primary tumor site, and high LDH and NSE levels conferred a significant difference. The IPOG-NBL-92 protocol has proved to be satisfactory with tolerable toxicity and reasonable CR and survival rates. However, more effective treatments suitable to Turkeys social and economic conditions are urgently needed for children over 1 year of age with advanced neuroblastoma.

Delayed renal excretion of methotrexate after a severe anaphylactic reaction to methotrexate in a child with osteosarcoma.

Although methotrexate is an agent widely used in the practice of pediatric oncology, allergic reactions to methotrexate are most unusual. Most of these reactions typically occur after repeated administration. Here, we report a severe anaphylactoid reaction to the first dose of high-dose methotrexate infusion in a child with osteosarcoma who has also experienced a delayed excretion of methotrexate. Clinicians must be aware of the possibility of a systemic, near-fatal anaphylactic reactions with methotrexate and patients who experience severe anaphylactic reactions should be followed carefully because of the possibility of delayed methotrexate excretion.

Surveillance imaging and cost effectivity in pediatric brain tumors

OBJECTIVE The purpose of this study was to determine the role and cost effectiveness of surveillance imaging at the management of pediatric brain tumors. MATERIALS AND METHODS In this study, the imaging and clinical finding of 59 patients who had been diagnosed and followed by the Dokuz Eylul University Pediatric Oncology Group as primary central nervous system tumors between 1988 and 2000 were retrospectively evaluated. RESULTS We found that the 87.5% of tumor recurrence occurs within 21 months and 93.8% occur within 29 months. About 25% of these recurrences were asymptomatic and these (n=16) could be detected by surveillance imaging with a frequency rate of 1.59%. The cost of imaging for our patients was calculated to be 788 US

Tc-99m MDP, thallium-201 chloride and Tc-99m MAG3 renal uptake in subacute and chronic radiation nephritis compared

(mean) for a follow-up period of 24 months which would have been 739 US

Hyperglycemia and acute parotitis related to L-asparaginase therapy.

if a standard surveillance protocol would have been followed. CONCLUSION Surveillance imaging is an effective follow-up in detecting symptomatic recurrence in pediatric brain tumors.

Prognostic significance of anaplasia and angiogenesis in childhood medulloblastoma: a pediatric oncology group study.

The authors present a comparison of the findings for thallium-201 (Tl-201), Tc-99m MAG3 and Tc-99m MDP in subacute and chronic radiation nephritis in a 9-yr-old boy who was treated by radiation therapy for alveolar rhabdomyosarcoma of the left chest wall by a radiation port that partially included the left kidney. Tl-201 imaging three and six months later showed a cortical defect in the left kidney due to radiation nephritis. Tc-99m MDP scan showed increased uptake on both occasions, but more marked in the subacute period than in the chronic period. Tc-99m MAG3 showed decreased concentration and increased cortical retention three months later. Six months after the radiation therapy, a cortical defect corresponding to the cortical area that showed increased parenchymal retention was more prominent in the Tc-99m MAG3 scan.In the present case, Tc-99m MDP, Tl-201 and Tc-99m MAG3 findings may provide useful information for understanding pathophysiological damage in the kidney after radiation.

Treatment outcome of adolescents with acute lymphoblastic leukemia

In a boy with non-Hodgkins lymphoma (NHL), two different complications developed concurrently associated with L-asparaginase (L-ASP) therapy. A non-ketotic hyperglycemic state was observed simultaneously with bilateral acute parotitis after the patient was subjected to L-ASP. The hyperglycemia with normal insulin levels and the absence of plasma and urine ketones was controlled with insulin therapy and no residual impairment of glucose tolerance was demonstrated later. Bilateral acute parotitis, which is a rare complication associated with L-ASP, resolved spontaneously within a week after cessation of L-ASP. The rarely observed toxic effects of L-ASP, such as parotitis, should be recognized as promptly as the better-known complications, e.g., hyperglycemia, to avoid the continuation of this antineoplastic agent.