Maria Kalmanti

Gonadal function in young patients successfully treated for Hodgkin disease

BACKGROUND Gonadal function in pediatric and young adult survivors of Hodgkin disease is not very well defined. This study evaluates the outcome following the Multiple Drug Protocol (MDP) and the results are compared to the published experience. PROCEDURE Ovarian and testicular function was assessed in 65 patients (36 males) with Hodgkin disease in first or second complete remission after treatment with either radiation (RT, n = 13), chemotherapy (CT, n = 9), or both (n = 43). Chemotherapy consisted of six cycles of the MDP (doxorubicin, procarbazine, prednisone, vincristine, and cyclophosphamide). Median age at diagnosis was 13.1 years (range, 2.4-22.6) and median age at evaluation was 22.6 years (range, 15.1-33.7), which was 6.7 years (range, 2.0-19.8) after the completion of all treatments. For the purpose of analysis, patients were divided into three groups: group A, patients who received only RT that did not include the pelvis (8 females, 5 males); group B, patients who received CT but no pelvic RT (15 females, 25 males); and group C, patients who received CT plus pelvic RT (6 females, 6 males). RESULTS All patients progressed spontaneously through puberty and evaluable patients were found to be sexually mature (Tanner stage IV and V). Serum follicle stimulating hormone (FSH) was increased in 0/5, 13/25, and 5/6 and testicular volume was decreased in 1/3, 4/11, and 2/3 group A, B, and C male patients, respectively. Leydig cell dysfunction was uncommon; 91% and 88% of males had normal serum concentrations of luteinizing hormone (LH) and testosterone, respectively. FSH and LH were increased in 0/8, 3/15, and 2/6 group A, B, and C female patients, respectively, at last follow-up, indicating a 17% prevalence of ovarian dysfunction. Serial data in seven females whose initial levels of FSH/LH were elevated revealed normalization in four. Six females delivered eight normal children. CONCLUSIONS The majority of males who received CT +/- RT have evidence of germ cell dysfunction, while Leydig cell function is unaffected in most. In females, although abnormal function early after the end of treatment was observed, ovarian function remained or returned to normal in most young women. Thus, in females the results of hormone testing performed early after treatment may not be predictive of their eventual reproductive potential.

Stem Cells: Promises Versus Limitations

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.

Altered actin polymerization dynamics in various malignant cell types: evidence for differential sensitivity to cytochalasin B☆

Using the DNase I inhibition assay, fluorimetric measurements, and immunoblot analysis, we studied quantitatively changes in the actin polymerization dynamics in primary cultures of normal and malignant human lymphocytes, normal human endometrial cells, and in various leukemic and endometrial adenocarcinoma cell lines. The G/total-actin ratio of malignant cells was found to be 1.37 to 1.81-fold higher compared to normal cells, indicating that malignant cells express reduced amounts of polymerized actin. The above findings were corroborated by fluorescence measurements of the amounts of rhodamine-phalloidin-labeled F-actin in normal and neoplastic cells, which showed significantly lower F-actin content in malignant cell preparations. Moreover, the total actin content, as quantitated by the DNase I inhibition assay and by immunoblot analysis, was found to be significantly decreased in the primary cultures of malignant human lymphocytes and endometrial cells when compared to the total actin levels in corresponding normal cells. Proliferation and viability measurements of normal and neoplastic cells in culture, treated equally with cytochalasin B (CB), revealed an increased susceptibility of malignant cells to this anticytoskeletal agent. This was not due to increased CB incorporation in neoplastic cells, as indicated by 3H-CB uptake experiments. In addition, fluorescence microscopy, in the presence of graded concentrations of CB, showed destabilization of microfilaments in the poorly differentiated endometrial adenocarcinoma HEC-50 cells, compared to the well-differentiated Ishikawa cells. In conclusion, all investigated malignant cells are characterized by: (a) higher G/total-actin ratio; (b) decreased F- and total-actin content; and (c) lower resistance to CB treatment. These quantitatively determined parameters may represent potential biochemical indicators reflecting malignant transformation. Moreover, it seems worthwhile to explore whether or not the differential sensitivity of malignant cells to anticytoskeletal drugs may provide a valuable approach to the manipulation of malignant cells.

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

Abstract.  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 medicine.

Insulin-like growth factor-I and binding protein-3 in relation to childhood leukaemia

The aetiology of most cases of childhood leukaemia remains unknown, but several studies have indicated that increased birthweight and height are risk factors for the disease. Since insulin‐like growth factor‐I (IGF‐I) mediates the effect of growth hormone and has been positively associated with prostate cancer, we have evaluated the role of this hormone and its principal binding protein, IGFBP‐3, in the aetiology of childhood leukaemia. Incident cases of childhood leukaemia from those recorded by a national network of childhood oncologists were enrolled in our study. Controls were children hospitalised for acute conditions of no more than moderate severity with matching for gender, age and maternal place of residence. Blood measurements of IGF‐I and IGFBP‐3 were undertaken using commercially available radioimmunoassays. Serum IGF‐I values decreased by about 1.7% per month, and the rate of decline was higher, though not significantly so, among cases (2.1% per month) than among controls (1.4%). There was no significant association between IGF‐I and the likelihood of childhood leukaemia, but an increment of 1 μg/ml of IGFBP‐3 was associated with a substantial and statistically significant reduction of childhood leukaemia by 28% (95% confidence interval 7% to 45%). Because IGFBP‐3 is essentially a binding protein, we interpret our findings as indicating that bioavailable IGF‐I may play an important role in the aetiology of childhood leukaemia. The much smaller quantities and the inherent instability of IGF‐I in the blood in comparison to those of IGFBP‐3 are likely to hinder documentation of an underlying positive association of IGF‐I with the disease. Int. J. Cancer80:494–496, 1999.

Comparative study of stemness characteristics of mesenchymal cells from bone marrow of children and adults

BACKGROUND AIMS Age-related changes that could affect the biologic features of mesenchymal stromal cells (MSC), such as a decrease in proliferation and osteoblast differentiation capacity and an increase of senescence markers and apoptosis, have been reported recently. The aim of this study was the evaluation of age-related characteristics and the correlation of age with the functional properties of MSC. METHODS The doubling time (DT), colony-forming unit–fibroblast (CFU-F) colonies and surface antigen expression of MSC isolated from bone marrow (BM) of children (C-MSC) were compared with those from adults (A-MSC). The expression of Oct-4 and Nanog transcripts and the relative telomere length were evaluated in both groups. RESULTS DT values were lower in C-MSC compared with A-MSC, and a higher CFU-F count was observed in children. However, the expression of Oct-4 and Nanog did not differ between C-MSC and A-MSC and was not correlated with the proliferative capacity. The telomere length was significantly higher in C-MSC compared with A-MSC. CONCLUSIONS These data suggest that childrens BM-derived MSC could be a more advantageous source of these cells for tissue engineering and cell therapy.

In vitro fertilization and risk of childhood leukemia in Greece and Sweden.

Cancer risk in children born after in vitro fertilization (IVF) remains largely unknown. We aimed to investigate risk of leukemia and lymphoma following IVF using two nationwide datasets.

Urine Interleukin-8 as a Marker of Vesicoureteral Reflux in Infants

OBJECTIVE. Vesicoureteral reflux (VUR) is a common finding in children presenting with urinary tract infection (UTI) and prenatally diagnosed urinary tract dilatation and in relatives of index patients. Children with VUR are at risk for ongoing renal damage with subsequent infections. Detecting VUR and renal scarring currently depends on imaging modalities with associated problems of radiation, invasiveness, and expense. Noninvasive methods would greatly facilitate diagnosis and would also help in identifying relatives of index cases who should be screened. Interleukin-8 (IL-8) is produced by epithelial cells of the renal tract in response to inflammatory stimuli and has been shown to increase during acute UTI. The objective of this study was to assess the urine levels of IL-8 as a noninvasive marker of VUR in infants in the absence of a recent UTI episode. METHODS. We evaluated urine concentrations of IL-8 in 59 infants aged 1 month to 2 years. All infants were free of UTI for a minimum of 3 weeks before IL-8 evaluation. Infants were divided into 3 groups: group A, subjects with proven VUR (24 infants aged 0.15–1.95 years, median 0.43); group B, subjects with a history of UTI but negative investigation for VUR (14 infants aged 0.32–1.95 years, median 0.57); and group C, subjects without any history of acute or chronic condition that might impair renal function (21 infants aged 0.08–1.92 years, median 0.33). IL-8 concentrations were determined by a commercially available quantitative enzyme-linked immunosorbent assay. To avoid dilution effects, urinary levels of IL-8 were expressed as the ratio of cytokine-to-urinary creatinine. RESULTS. Results were presented as medians and ranges. The Kruskal-Wallis test, the Mann-Whitney rank sum U test, and the Spearman rank order correlation test were performed for the univariate analysis. Two-tailed P values were calculated and the conventional level of significance P < .05 was applied in all cases. Infants in groups A and B had been free of UTI for a period of 3 to 52 weeks (median, 5.0 weeks) and 3 to 78 weeks (median, 4.5 weeks), respectively, before IL-8 determination. No significant difference was noted in the length of the UTI-free period between groups A and B (P = .469). Urine creatinine concentrations did not differ among groups A, B, and C (medians 1.15, 2.25, and 1.15 μmol/mL, respectively; P = .080). The median urine IL-8/creatinine concentrations (pg/μmol) were 40.5 (range, 2.04–3874) in group A, 1.91 (range, 0.001–386) in group B, and 2.47 (range, 0.002–55.6) in group C. Urine IL-8/creatinine concentrations were significantly higher in group A than both in group B (P = .0003) and in group C (P < .0001). No significant difference was observed between groups B and C (P = .749). In group A, no significant correlation was shown between IL-8/creatinine concentrations and the presence of renal parenchymal damage (P = .506), reflux grade (P = .770), or time from UTI (P = .155). A receiver-operator characteristic curve was constructed by plotting the sensitivity versus the specificity for different cutoff concentrations of IL-8/creatinine. With a cutoff concentration of urinary IL-8/creatinine at 5 pg/μmol, the sensitivity of this marker in diagnosing VUR was 88%, the specificity 69%, the positive prognostic value 66%, and the negative prognostic value 89%. In higher cutoff concentrations, specificity of the marker increased but sensitivity rapidly decreased. CONCLUSIONS. We present evidence that urine IL-8 concentrations remain elevated in infants with VUR even in the absence of UTI and that a cutoff of 5 pg/μmol IL-8/creatinine is of high sensitivity and adequate specificity for diagnosing VUR. Elevated urine IL-8 levels in VUR and renal scarring have already been reported; however, the present study is, to our knowledge, the first to confirm significant differences between infants with VUR and infants with a history of UTI alone and healthy controls, and to suggest a reliable cutoff concentration for diagnosing VUR. Our findings additionally suggest that inflammatory process in VUR is ongoing even after UTI has resolved, pointing against the currently held belief that sterile reflux cannot harm kidneys. The chronic inflammatory cell infiltrate associated with reflux nephropathy rather than VUR itself might offer an explanation for the secretion of IL-8, which may well be independent of reflux grade. Using urine IL-8 for diagnosing VUR is not free of limitations, because IL-8 may be elevated as a result of urinary tract manipulation or undetected UTI. In addition, this study focused on infants and not in older children with longstanding VUR. Increased urine IL-8 concentrations after UTI has resolved is a promising noninvasive marker for an initial screening for VUR in infancy with high sensitivity and adequate specificity.

Prophylaxis with urokinase in pediatric oncology patients with central venous catheters.

This study evaluated the effects of urokinase in the prevention of central venous catheter (CVC)-related complications in children with malignancy. Fifteen patients with 16 CVCs (study group A) received an intraluminal application of urokinase (10,000 IU in each catheter lumen for 4 h) once a week. They were monitored prospectively with quantitative blood cultures and ultrasonography (color Doppler ultrasound of the great veins and echocardiography). The rate of complications was compared with that of 15 children with 19 CVCs without thromboprophylaxis, treated the previous year (control group B). The authors found a significantly lower incidence of CVC dysfunction (3/16 versus 13/19), no major thrombosis, fewer CVC-related bacteremias (2/16 versus 8/19), and a higher salvage of CVCs (1/16 versus 5/19 CVC removals due to persistent bacteremia) in the thromboprophylaxis group. Asymptomatic thrombosis rate was also lower (7/16 cases in group A versus 9/11 in group B when sonography was performed). No hemorrhagic complications were noted. Thromboprophylaxis with urokinase seems a safe and effective measure for reducing the rate of CVC-related complications.

Treatment with Recombinant Human Erythropoietin in Children with Malignancies

The effect of recombinant human erythropoietin (rHuEPO) on the anemia of cancer was examined in 15 children with hematologic malignancies (group I) and solid tumors (group II), whose hemoglobin (Hb) was under the third percentile for sex and age. The response to rHuEPO was defined as an increase of Hb to above the 10th percentile following 8 weeks of therapy. The rHuEPO caused an increase in the Hb and hematocrit (Hct) in 46% of children of both groups at a dose of 150 IU/L, in 28.5% of children at a dose of 250 IU/L and in 25.5% of children at a dose of 400 IU/L. Leukocyte and platelet counts were not influenced by the rHuEPO treatment. The red cell transfusion requirement decreased to 66% in both groups after rHuEPO treatment. Erythropoietin (EPO) levels were measured prior to the treatment and then every 4 weeks during rHuEPO treatment. Children who responded to EPO had an initial EPO level of < 100 IU/L, while those who did not respond had an initial EPO level of > 100 IU/L. Erythropoietin was well tolerated in all children, with no side effects.