Deregulated WNT signaling in childhood T-cell acute lymphoblastic leukemia.

WNT signaling has been implicated in the regulation of hematopoietic stem cells and plays an important role during T-cell development in thymus. Here we investigated WNT pathway activation in childhood T-cell acute lymphoblastic leukemia (T-ALL) patients. To evaluate the potential role of WNT signaling in T-cell leukomogenesis, we performed expression analysis of key components of WNT pathway. More than 85% of the childhood T-ALL patients showed upregulated ß-catenin expression at the protein level compared with normal human thymocytes. The impact of this upregulation was reflected in high expression of known target genes (AXIN2, c-MYC, TCF1 and LEF). Especially AXIN2, the universal target gene of WNT pathway, was upregulated at both mRNA and protein levels in ∼40% of the patients. When ß-CATENIN gene was silenced by small interfering RNA, the cancer cells showed higher rates of apoptosis. These results demonstrate that abnormal WNT signaling activation occurs in a significant fraction of human T-ALL cases independent of known T-ALL risk factors. We conclude that deregulated WNT signaling is a novel oncogenic event in childhood T-ALL.

Cost-effectiveness of cefepime + netilmicin or ceftazidime + amikacin or meropenem monotherapy in febrile neutropenic children with malignancy in Turkey.

Infection remains the major cause of morbidity and mortality in immunocompromised children with malignancy. In addition, the economic impact of antibiotic treatment should always be evaluated, especially in developing countries. In our center between January 1998 and January 1999, 73 children with hematological malignancies [acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML)]; 9 children with solid tumors (rhabdomyosarcoma, neuroblastoma) had 87 febrile neutropenic episodes (related to chemotherapy). These children were randomized prospectively into three treatment groups. The first group (n: 28) received cefepime plus netilmicin, while the second group (n: 29) was treated with ceftazidime plus amikacin and the third (n: 30) with meropenem as monotherapy. The aim of the study was to compare the success rates and cost of fourth generation cephalosporin plus aminoglycoside and monotherapy of meropenem with ceftazidime plus amikacin, which is the standard therapy for febrile neutropenia. Microbiologically documented infections were 29.9%, clinically documented infections were 9.2% and 60.9% of the febrile neutropenic episodes were considered to be FUO. Gram-positive microorganisms were the most commonly isolated agents from blood cultures [MRSA (Methicillin Resistant Staphylococcus aureus) in 6 patients and MSSA (Methicillin Sensitive Staphylococcus aureus) in 4 patients]. The success rates were 78.5%, 79.3% and 73.3 % for the 1st, 2nd and 3rd groups respectively. In 4 patients (4.5%) fever responded only to amphotericin-B therapy. There was no statistically significant difference between the three treatment regimens with respect to efficacy, safety and tolerance (chi2 test, p>0.05), but while the third and fourth generation cephalosporins + aminoglycosides were comparable for cost, the monotherapy regimen was the most expensive. The main determining factors for the choice of treatment of febrile neutropenic children, especially in a developing country, are cost, presence of indwelling catheter and the bacterial flora of the unit, as well as efficacy.

Serum zinc and copper levels in southeastern Turkish children with giardiasis or amebiasis.

Alterations of serum zinc (Zn) and copper (Cu) concentrations are commonly found in patients suffering from gastrointestinal infections and with hepatic, renal, cardiovascular, and malignant diseases. In this study, the serum Zn and Cu levels in 20 children with giardiasis and in 40 children with amebiasis were evaluated. The serum Zn levels showed a significant decrease when compared to controls (p<0.001). After metronidazole therapy, a significant increase in Zn levels was observed (p<0.001). There was no significant difference in serum Cu levels between patients and controls before therapy. Before therapy, the serum Cu/Zn ratio in children with either giardiasis or amebiasis was significantly higher than that of the control group. After therapy, the Cu/Zn ratio was found to be back to normal. There were no significant differences in serum Zn levels and Cu/Zn ratios between children with and without diarrhea and there was no significant difference in children with or without failure to thrive. We concluded that Zn deficiency and elevated Cu/Zn ratio could be acute-phase responses to parasitic infections in children with giardiasis or amebiasis and that a successful treatment of the primary disorder will lead to complete recovery. Further studies are in progress to confirm the benefit of Zn supplementation during the acute phase of the disease, particularly in zinc-deficient regions of the world, such as in the case of Turkey.

Results of rhabdomyosarcoma treatment in a developing country.

Fifty-one children (median age: 4.5 years; 4 months-16 years) diagnosed with rhabdomyosarcoma were treated in our center between 1980-1999. The primary sites were head and neck in 31.4%, the genito-urinary system in 21.6%, and extremities in 9.8% of the patients. The histopathologic subtypes were embryonal in 80.4%, alveolar in 9.8%, and undifferentiated in 9.8%. The majority of the patients were considered group III (47%) and group IV (25.5%) according the criteria of the Intergroup Rhabdomyosarcoma Study (IRS). Primary total tumour resection was performed in only 27.5% of the patients. The patients were treated with assigned regimens of IRS II and IRS III protocols. Radiotherapy was applied to 92.1% of the patients. Thirty-four patients (66.7%) were lost to follow up, and of the remaining 17 patients, 7 patients (41.2%) died, relapse occurred in 9 patients (52.9%) and 10 patients (58.8%) are alive. The percentage of cases lost to follow up during the first 10 years and the following 9 years of the study were 77.4% and 50%, respectively. In compliance with cancer treatment remains a major problem in developing countries.

Protein C and antithrombin III in children with acute leukemia.

In this study Protein C (PC) and antithrombin III (AT III) levels in childhood acute leukemia were investigated. The mean PC activity levels in 19 newly diagnosed cases of acute leukemia were significantly lower as compared with the normal controls (p < 0.05). A significant increase was found (p < 0.01) in the patients in remission. Prior to treatment 78.8 percent of patients had decreased PC activity levels, but all patients had normal PC activity during remission. Decreased PC activity levels were found to be independent of the leukocyte count and liver function. No statistically significant difference was found in the AT III antigen levels between the untreated patients, the patients in remission and the control group. Our results indicate that apart from thrombocytopenia, low PC activity levels and alterations in fibrinolysis and coagulation may be responsible for the hemorrhagic manifestations observed in cases of acute leukemia.

The association between palatal grooves in upper incisors and periodontal complications.

Palatal groove is a rare morphological defect of upper incisors, frequently associated with localized destruction of periodontal tissue with endodontic complications. In this study, a sample of 1,081 male, young adult subjects, aged 20 to 22, palatal grooving was recorded in 11 (1.01%) subjects, affecting 15 incisors. Among 634 adult subjects, aged 35 to 50, with periodontal disease, palatal groove was found in 5 (0.79%) incisors. Second incisors were more frequently (75%) associated with this anomaly. In the young adults, the mean probing pocket depth in the groove region and around other teeth of the intercanine area was 3.8 mm and 1.2 mm, respectively. In the group of periodontal patients, the mean probing pocket depth was significantly greater at the site of palatal groove (8.8 mm vs. 4.0 mm).