AIM: We investigated pituitary-ovarian function in young women after treatment for different cancers in prepubertal and pubertal periods, with or without radiotherapy of infradiaphragmatic areas. PATIENTS AND METHODS: We analyzed the values of follicle-stimulating hormone (FSH) luteinizing hormone (LH), estradiol (E2), inhibin B and anti-müllerian hormone (AMH) in the group of 28 young women aged 18.6 +/- 4.7 years, who had been treated for Hodgkin's Lymphoma HL (n=16), nephroblastoma (n=7), soft tissue sarcoma (n=4), neuroblastoma (n=1). Abdominal irradiation was given in fifteen survivors. Control group was composed of ten healthy women at similar age. RESULTS: In the whole group the mean levels of FSH, LH and E2 did not differ from the control group, but in the subgroup irradiated infradiaphragmatically FSH concentration was higher than in the control group (8.06+/-3.28 vs 5.8+/-2.03 mIU/ml) p=0.042, particularly after HL treatment (8.53+/-3.25 mIU/ml), p=0.045. Mean AMH levels were significantly lower in the whole analyzed group than in the control one (22.8+/-16.3 vs 29.4+/-13.2 pmol/l) p=0.036, particularly in the subgroup irradiated for abdomen (17.2+/-14.9 pmol/l) p=0.025. Inhibin B was also lower in the whole group,(27.98+/-17.8 ng/l vs 47.9+/-26.4 ng/l) p=0.035, and in the subgroup with non-irradiated abdomen 25.9+/-14.1 ng/l, p=0.01. We did not observe the influence of age at treatment (prepubertal vs pubertal period) on the values of analyzed hormones. We found a correlation between AMH and inhibin B. CONCLUSIONS: In young women after anti-cancer treatment, with normal menstrual cycles, the signs of ovarian dysfunction and diminished ovarian reserve are observed. This situation can lead to a shorter period of fertility. Those women should be informed about their reproductive potential.

INTRODUCTION: Composed anticancer treatment leads to different late effects, such as ovarian failure, causing infertility or premature menopause. AIM OF THE STUDY: was to analyse ovarian function, particularly anti-mullerian hormone levels, in young females after anticancer treatment. PATIENTS AND METHODS: We analysed FSH, LH, estradiol and anti-mullerian hormone (AMH) levels on days 3-5 of a menstrual cycle in thirty three cancer survivors in mean age 19.1+/-4.7 years treated in age 12.0+/-5.6 years for Hodgkin Lymphoma (HL)(n=16), nephroblastoma (n=7), soft tissue sarcoma (n=4), germinal tumor (n=3), neuroblastoma (n=2), histiocytosis (n=1). Infradiaphragmatic radiotherapy was needed in 16 patients (10 treated for HL). Results were compared with healthy girls of the same age. RESULTS: The mean values of FSH, LH, E2 and AMH did not differ in all survivors comparing to controls. Patients treated for HL with chemo- and radiotherapy presented higher FSH levels than controls (8.53+/-3.25 vs. 5.8+/-2.03 mIU/ml; p=0.045). Mean AMH levels were lower in all patients that received radiotherapy for the infradiaphragmatic region (17.19+/-14.84 pmol/l) than in controls (29.40+/-13.2 pmol/l; p=0.037). Particular analysis of all cases showed higher (>2 SD) FSH levels in 8 patients: 5 patients treated for HL with radiotherapy and higher total doses of procarbazine, nitrogen mustard and vinblastine; 2 patients treated for soft tissue sarcoma and one patient for Wilms tumor (all received radiotherapy). Lowered AMH levels were found in 8 patients treated with chemo- and radiotherapy (4 - for HL, 2 - for Wilms tumor and 2 - for soft tissue sarcoma). CONCLUSION: Composed anticancer treatment, especially radiotherapy, leads to ovarian failure. Decreased AMH values at young adulthood suggest a lower ovarian reserve. All causes and first symptoms of ovary damage should be known to the doctors who take care of the patients after anticancer treatment.

The aim of study was to compare the clinical picture and results of laboratory tests according to the acute lymphoblastic leukaemia (ALL) immunophenotype. The observation was carried out on a group of 67 patients treated in the IIIrd Department of Paediatrics and Department of Children Oncology in the Medical Academy of Białystok from January 1994 to April 2001. This group consists of 4 children with pro-B acute lymphoblastic leukaemia, 52 children with pre-B cell ALL, 1 child with B-cell acute lymphoblastic leukaemia and 9 children with T-cell acute lymphoblastic leukaemia. Haemorrhagic diathesis. splenomegaly, enlargement of peripheral lymph nodes as well as higher values of white blood cells count, blasts count, haemoglobin concentration, haematocrit and LDH activity were observed more frequently in patients with T-cell leukaemia than in others.

Testicular function was evaluated in 59 male (27 prepubertal and 32 pubertal) survivors treated for ALL according to two different protocols. Serum inhibin B, FSH, testosterone, LH, and testicular volume were measured. In both groups the mean values of inhibin B were lower than control, whereas the other analyzed parameters were comparable. The inhibin B-to-FSH ratio was reduced as compared to the control. Testicular volume was lower than in healthy pubertal patients. The results show that treatment for ALL has a negative effect on spermatogenesis, regardless of the age at treatment and type of therapy.

INTRODUCTION: The survival rate after the treatment for Hodgkin lymphoma improved in the last three decades and the late effects of anticancer therapy, particularly gonadal toxicity, became an important problem. THE AIM OF WORK: Assessment of the influence of chemo- and radiotherapy on gonadal function in young male survivors after the treatment for Hodgkin lymphoma (HL). MATERIAL AND METHODS: Levels of inhibin B, testosterone, FSH, LH and testicular volume were measured in 26 HL survivors aged from 15.6 to 25.2, who had been treated for HL in prepubertal (n=8) or pubertal (n=18) period. RESULTS: 1. In all groups, comparing to control one, we found higher FSH concentration (15.2+/-12.3 IU/l vs. 3.3+/-1.2 IU/l); p=0.0004, lower inhibin B (60.9+/-44.5 ng/l vs. 198.1+/-58.1 ng/l); p=0.0001, lower testicular volume (18.2+/-2.6ml vs. 21.3 +/-5.1ml) p=0.01 and normal LH as well as testosterone values. 2. Higher >+2SD FSH and LH were found in 62% and 23%, respectively, and lower <-2SD inhibin B - in 72% of survivors. 3. We did not observe the differences between the patients: a) treated before and during puberty and b) the patients in different stages of disease. 4. Persistently lowered inhibin B concentration and higher, but gradually normalized values of FSH were found >6 years after the end of therapy, 5. Azoospermia was observed in 4/10 patients, oligospermia - in 4/10 and normospermia - only in 2/10. CONCLUSIONS: Anticancer treatment for HL, independently of the age at diagnosis and clinical stage, leads to serious and persistent gonadal dysfunction. The patients should be informed about the problem of gonadal toxicity and possibility of fertility preservation at the moment of diagnosis.

There is a rising interest in the field of immunotherapy in cancer in the last few years. One of the methods is to prevent the immunosuppression accompanying neoplastic diseases including acute lymphoblastic leukaemia (ALL) in children. In healthy people regulatory T cells (Tregs) prevent the autoimmune, destructive activation of T lymphocytes. However, the hyperfunction of Tregs will lead to impairement of the immune system. The aim: of our study was to determine the Tregs (including molecules important for their function) in the peripheral blood of children with ALL. Material and methods: Thirty children were enrolled into our study, the assessment of Tregs was performed with flow cytometry including the following antigens: CD4, CD10, CD19, CD25, CD28, CD45, CD45RA, CD45RO, CD54 (ICAM-1), CD62L, CD69, CD103, CD127, CD134 (OX40), CD152 (CTLA-4), GITR. Results: 1. The percentages of Tregs were higher in the blood of the examined group, however the difference was not statistically significant; 2. In the examined group higher percentage of Tregs with the coexpression of CD45RA, CD134 and CD152 antigens were noted; 3. The percentages of Tregs with coexpression of CD62L (with or without CD103) and CD54 were lower then in the control group; 4. We did not observe differences in Tregs with coexpression of CD11a, CD27, CD28, CD45RO, CD69, CD103, GITR antigens between the examined and the control group. Conclusions: The finding of smaller number and lower percentage of regulatory T cells with coexpression of CD62L or lack expression of CD103 in children with ALL as compared to the control group, may be interpreted as activation of Treg cells and one of the mechanisms of immunosuppression in cancer of children. Further studies in this direction are needed.

The structure, shape, size, growth and mineralization of bones are results of constant bone creation and its' resorption, described as bone turnover. The two first decades of life, when the peak bone mass is gained, seems to be the most important for further skeletal changes. Thus closer examination of such factors as gender, weight, height, bone age, pubertal status, lean body and fat mass, as well as environmental factors at particular age should be conducted. Since there are no clear criteria for small bone mass in the population of children and adolescents, an even more complicated situation for establishing bone status is with the cohort of children with chronic diseases. Childhood cancer and its' treatment are additional negative influences for bone gain and therefore it could contribute to osteopenia and osteoporosis in the adult.

INTRODUCTION: Bone marrow transplantation from HLA identical family donors is the treatment of choice for children with severe aplastic anaemia (SAA). When there is no donor available, combined immunosuppressive therapy is given. AIM: evaluation of results of immunosupressive therapy in children with severe aplastic anaemia. Material and methods: SAA was diagnosed in 105 children (42 girls, 73 boys), aged 2-18 years, in the eleven haematological centres in Poland, between 1993-2007. All patients received the Severe Aplastic Anaemia Working Party of the EBMT protocol which included: antilymphocyte globulin or antithymocyte globulin, cyclosporin A, prednisolone. Granulocyto- or granulocytomacrophagic-cell stimulation factor was additionally administered during deep neutropenia. Haematological response was evaluated on day 84 or 112 and 180 of the therapy. RESULTS: complete remission occurred in 53 patients (51.5%), partial remission in 27 (24.7%), no response was obtained in 25 children (23.8%) on day 180, of the therapy. Period of observation was from 12 months to 12.5 years. During this time relapse occurred in 10 patients (9.5%). We observed 22 deaths: 8 early, during the first 3 months of IS and 14 after the first 3 months of immunosuppresive therapy (IS). At present 70 children (66.6%) are in first remission with lasts from 12 months to 12.5 years. The survival at 12.5-years is 78.6%. During the 12.5 years of follow-up we had two cases with a late clonal complication (PNH and MDS). Transformation to acute nonlymphoblastic leukaemia was observed in two of our patients. CONCLUSIONS: 1. Immunosuppresive therapy (IS) in children with SAA, without bone marrow family donors, is more effective after introduction of combined IS (12.5 years survival in this study was 80% for children with very severe aplastic anaemia (v SAA). 2. In our studies among the children followed up after IS therapy, there were: 1 case of periodic nocturnal haemoglobinuria (PNH), 1 case of myelodysplastic syndrome (MDS) and 2 cases of myeloid leukaemia (probability of incidence was 3.8%).

PURPOSE: Complete treatment for Hodgkin's lymphoma (HL) may disturb functioning of different organs leading to deteriorated quality of future life. Endocrine complications are one of the most common and may be the result of radiotherapy of neck, mediastinal and infradiaphragmatic regions, as well as chemotherapy, especially with alkylating agents. The aim of our study was to analyse gonadal and thyroid disturbances in young adults after the treatment for HL in childhood. MATERIAL AND METHOD: In 36 adolescents and young adults (19 males; mean age 20.5+/-3.1) 5.9+/-3.4 years after treatment for HL, we have examined the thyroid function (TSH, thyroxine-T4, tri-iodothyronine-T3, ultrasound) as well as gonadal function in males: FSH, LH, testosterone, inhibin B and in females: FSH,LH, estradiol, inhibin B and anti-müllerian hormone (AMH). Radiotherapy of supradiaphragmatic region was used in 34/36 patients and for infradiaphragmatic region in 17 patients (7 males). Chemotherapy was composed of B-DOPA and MVPP protocols. RESULTS: 1. Signs of subclinical hypothyroidism (elevated TSH) were found in three survivors (irradiated on upper mediastinum). Ultrasonic abnormalities (simple nodules) were found in three patients after mantle radiotherapy. 2. In males the mean values of FSH were higher than in healthy boys (16.0 mIU/ml+/-13.0 vs 3.9 mIU/ml+/-2.0) p=0.0004, inhibin B- lower (50.1 ng/L +/- 43.5 vs.68.1 ng/L +/- 77.2) p = 0.0001, and testicular volume lower (17,3 ml+/-3.8 vs 18.5 ml+/-4.8) p = 0.05. The mean values of LH and testosterone were normal. Inhibin B<2SD and FSH>2SD in 6/19 males, LH>2SD in 4 cases (irradiated infradiaphragmatically) were found. 3. In females, we observed higher FSH values (8.53 mIU/ml+/-3.25 vs 5.8 mIU/ml+/-2.03) p=0.045; lower AMH (17.19 pmol/L+/-14.84 vs 29.40 pmol/L+/-13.2) p=0.05 and tendency to lower inhibin B (31.47 ng/L+/-18.83 vs 47.9 ng/L+/-26.39) p=0.08 than in control group. LH and estradiol concentrations did not differ in between groups. FSH>2SD, inhibin B and AMH<2SD were found in 5 girls (infradiaphragmatic irradiations in 4 cases). CONCLUSIONS: Our observations show the possibility of different endocrine disturbances after combined treatment for HL, especially gonadal function disturbances. Considering these long-term complications, further follow-up is needed, even in the abscence of clinical symptoms.

The aim of this study was to evaluate the gonadal function in boys with newly-diagnosed acute lymphoblastic leukaemia, prior to therapy. PATIENTS AND METHODS: The analysis was evaluated in 48 boys with acute lymphoblastic leukaemia, at the time of diagnosis; 34 boys were prepubertal - Tanner stage of sexual maturation 1 (group I) and 14 - pubertal - Tanner stage 3-5 (group II). Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), inhibin B, testosterone and testicular volume were determined. RESULTS: In group I no alteration in hormonal status was observed, whereas in group II lower inhibin B was found (68.09 ng/l+/-54.87 vs 152.66 ng/l+/-72.09, p=0.0002). The levels of FSH, LH, testosterone and testicular volume did not differ from healthy adolescents. We did not observe a correlation between inhibin B and FSH concentrations. We did not find the influence of immunophenotype of leukaemic cells, leukocytosis, haemoglobin, platelets levels as well as LDH activity on the values of analyzed hormones. CONCLUSION: In adolescent boys with newly diagnosed leukaemia, lowered inhibin B values may suggest the damage of spermatogenesis even before the start of chemo- and radiotherapy. The small number of examined children requires confirmation on a larger group of patients.

INTRODUCTION: Acute lymphoblastic leukaemia (ALL) is a malignant clonal disease, one of the most common malignancies in childhood. Contemporary protocols ensure high remission rate and long term free survival. The ability of molecular genetic methods help to establish submicroscopic classification and minimal residual disease (MRD) follow up, in major percent responsible for relapse. OBJECTIVE: The aim of the study was to detect the frequency of IgH and TCR gene rearrangements and their correlation with clinical parameters. METHODS: Forty-one children with ALL were enrolled in the study group, with initial diagnosis of IgH and TCR gene rearrangements by polimerase chain reaction (PCR). MRD follow-up was performed in induction phase when morphological remission was expected, and after intensive chemiotherapy. RESULTS: In the study group IgH rearrangement was detected in 82.9% of children at the diagnosis, while TCR rearrangement was seen in 56.1%. On induction day 33, clonal IgH rearrangements persisted in 39% and TCR rearrangements in 36.5% of children. CONCLUSION: Molecular analysis of genetic alterations and their correlation with standard prognostic parameters show the importance of risk stratification revision which leads to new therapy intensification approach. MRD stands out as a precise predictive factor for the relapse of disease.

Many marketed drugs contain fluorine, reflecting its ability to modulate a variety of biological responses. The unique 20S proteasome inhibition profile of fluorosalinosporamide compared to chlorinated anticancer agent salinosporamide A (NPI-0052) is exemplary and relates to each halogen's leaving group potential. Crystal structures of fluoro-, hydroxy-, and bromosalinosporamide in complex with the yeast 20S proteasome core particle (CP) provide mechanistic insights into ligand binding and leaving group elimination and the ability to fine-tune the duration of proteasome inhibition. Fluorosalinosporamide/CP crystal structures determined over time offer striking snapshots of the ligand trapped with an intact fluoroethyl group in anticipation of fluoride elimination, followed by complete nucleophilic displacement of fluoride to give the highly stabilized cyclic ether found for salinosporamide A and bromosalinosporamide. This two-step reaction pathway is consistent with a mechanism for partially reversible proteasome inhibition by fluorosalinosporamide. Proteasome catalyzed fluoride displacement provides preliminary insights into the active site Thr1N pK(a).

There is a rising interest in the field of immunotherapy in cancer in the last few years. One of the methods is to prevent the immunosuppression accompanying neoplastic diseases including acute lymphoblastic leukaemia (ALL) in children. In healthy people regulatory T cells (Tregs) prevent the autoimmune, destructive activation of T lymphocytes. However, the hyperfunction of Tregs will lead to impairement of the immune system. The aim: of our study was to determine the Tregs (including molecules important for their function) in the peripheral blood of children with ALL. Material and methods: Thirty children were enrolled into our study, the assessment of Tregs was performed with flow cytometry including the following antigens: CD4, CD10, CD19, CD25, CD28, CD45, CD45RA, CD45RO, CD54 (ICAM-1), CD62L, CD69, CD103, CD127, CD134 (OX40), CD152 (CTLA-4), GITR. Results: 1. The percentages of Tregs were higher in the blood of the examined group, however the difference was not statistically significant; 2. In the examined group higher percentage of Tregs with the coexpression of CD45RA, CD134 and CD152 antigens were noted; 3. The percentages of Tregs with coexpression of CD62L (with or without CD103) and CD54 were lower then in the control group; 4. We did not observe differences in Tregs with coexpression of CD11a, CD27, CD28, CD45RO, CD69, CD103, GITR antigens between the examined and the control group. Conclusions: The finding of smaller number and lower percentage of regulatory T cells with coexpression of CD62L or lack expression of CD103 in children with ALL as compared to the control group, may be interpreted as activation of Treg cells and one of the mechanisms of immunosuppression in cancer of children. Further studies in this direction are needed.

BACKGROUND: The success rate for chemotherapy of adults with acute lymphoblastic leukaemia in Norway compares favourably with that in international reports, but improvements are still needed. Allogeneic stem cell transplantation is an option for patients up to 60 years and may contribute to improving the outcome for these patients. MATERIAL AND METHODS: Allogen stem cell transplantation was performed in 61 high-risk patients (38 men and 23 women) with acute lymphoblastic leukaemia at Rikshospitalet between 1985 and 2005. 19 patients were transplanted in first remission and 42 at a later stage of the disease. RESULTS: At the end of 2006, 26 patients (43%) were alive; 21 (35%) in complete remission and 5 with relapse. Median survival time was 1.5 years. Relapse was the most important cause of treatment failure (38%), but transplantation-related mortality (25%) was also a substantial problem. Estimated 5-year actuarial leukemia-free survival was 35 %. INTERPRETATION: Our results are in line with international reports on the results of allogen stem cell transplantation in high-risk acute lymphoblastic leukaemia. This treatment offers cure for patients with an otherwise dismal prognosis. A larger number of patients should be offered such treatment during the first remission than what was the case in the 20-year period this study took place.

Fevers, arthritis, myalgia and skin changes are the most typical features of rheumatic diseases, although one should remember that the same symptoms could mask neoplasm. This study shows that some patients with rheumatological symptoms treated in the Department of Lung Diseases and Children Rheumatology, Medical University of Lublin were finally diagnosed with neoplasm. In focus is the initial phase of the patients' illnesses. MATERIAL AND METHODS: We analyzed retrospectively the case histories of all patients admitted to the department between 1997 and 2005 (1560 hospitalizations). An oncological disease was diagnosed in 9 cases: leukemia in 4 children (acute lymphoblastic leukemia-ALL- in 3 cases, acute non-lymphoblastic leukemia-ANLL- in 1 case), Hodgkin's disease in 1 child, bone tumours in 2 children, liver tumour in 1 child and a tumour of the central nervous system in 1 child. CONCLUSIONS: The cases described should draw the physicians' attention to the fact that in the initial phase an oncological disease may be masked by rheumatological symptoms.

BACKGROUND. The determination of prognostic factors in acute lymphoblastic leukaemia (ALL) is increasingly important in establishing a correct treatment. We analyse the overall survival (OS), event free survival (EFS) and prognostic factors in our 16 years experience of treating acute lymphoblastic leukaemia. METHODS. We performed univariate and multivariate analyses of the prognostic factors we considered most significant in our serie of patients. RESULTS. From January 1989 to December 2005, 50 cases of ALL were reported in 58 patients with LA. We analysed a subgroup of 41 patients with LLA as they were included in standard protocols. In this group the EFS was 78% and OS 87.8%. Inmunophenotype is a predictor of prognosis when we compare Common with Others, with a HR of 13.82 (CI95%: 1.019-166.008) p<0.05; Protocol of Treatment of the Paediatric Haematology Oncology Society (SHOP)(94-99/89) with HR of 0.065 (CI95%: 0.005-0.008) p<0.02; and Age (>120 months/12-120 months) with a HR of 13.82 (CI95%: 0.58-329.48) p=0.1. CONCLUSIONS. The OS in our series is similar to that reported in the literature. Inmunophenotype and protocols of treatment are the most significant prognostic factors.

Neutrophilic metabolic activity was studied in 21 children with lymphoblastic leukemia during chemotherapy. After one-year chemotherapy, reduced cell activities of catalase and glutathione reductase were observed in children with septic complications during a follow-up in the presence of lower neutrophilic lactate levels. There was a direct correlation between lactate levels and catalase activity. Since the reduction in the levels of lactate in the neutrophils is attended by their apoptosis, this suggests that there is an association of delayed cell death with a fall in the phagocytic antioxidative defense potential.

AIM: To define incidence of HBV infection in patients with blood diseases caused by blood components transfusion; correlation between infection rate and blood disease nosological entity, intensity of hemoreplacement therapy, time of hepatitis B incubation period in patients with hematological malignancies after the diagnosis and initiation of polychemotherapy (PCT). MATERIAL AND METHODS: In 2000-2007 a prospective clinicoepidemiological trial was made to detect markers of HBV infection among 303 patients 15 to 76 years of age treated in the department of acute leukemia chemotherapy of N.N. Burdenko Military Hospital for acute lymphoid and myeloblastic leukemia, chronic myeloid leukemia in a blastic crisis, myelodysplastic syndrome in blast transformation, lymphoproliferative diseases with bone marrow affection. Statistic processing was performed with standard methods. RESULTS: HBV infection markers were detected in 30 (9.9%) of 303 examinees. Among the infected patients there were 16 (53.4%) patients with different variants of acute myeloblastic leukemia, 12 (40.0%) with different immunophenotypes of acute lymphoblastic leukemia, 1 (3.3%) patient with acute biphenotypical leukemia and 1 (3.3%) with lymphoma/leukemia. HBV infection was registered in patients 2 to 32 months after the beginning of the treatment. Most of the patients - 23 (74%) of 30 - were infected with HBV within the first year after hematological diagnosis and PCT induction course. HBV was diagnosed within treatment year two in 5 (16%) patients and within year three after PCT in 3 (10%). CONCLUSION: High incidence of HBV infection in patients with hematological malignancies points to a high epidemiological risk of hemoreplacement therapy, unsatisfactory quality of donor blood testing and necessity of updating methods of donor infection detection. To lower the risk of HBV infection in patients with hematological malignancies it is necessary to perform vaccine prophylaxis of hepatitis B before PCT.

High dose Methotrexate (MTX) has been extensively used for treatment of acute lymphoblastic leukemia (ALL). To determine the optimal dose of MTX in childhood relapsed ALL, the ALL-REZ BFM Study Group performed this prospective randomized study. A total of 269 children with a first early/late isolated (n=156) or combined (n=68) bone marrow or any isolated extramedullary relapse (n=45) of precursor B-cell (PBC) ALL (excluding very early marrow relapse within 18 months after initial diagnosis) were registered at the ALL-REZ BFM90 trial and randomized to receive methotrexate infusions at either 1g/m(2) over 36h (intermediate dose, ID) or 5g/m(2) over 24h (high dose, HD) during 6 (or 4) intensive polychemotherapy courses. Intensive induction/consolidation therapy was followed by cranial irradiation, and by conventional dose maintenance therapy. Fifty-five children received stem-cell transplants. At a median follow-up of 14.1 years, the 10-year event-free survival probability was .36 +/-.04 for the ID-group (n=141), and .38 +/-.04 for the HD-group (n=128, p=.919). The two groups did not differ in terms of prognostic factors and other therapeutic parameters. Conclusion. Methotrexate infusions at 5 g/m(2)/24h, as compared with 1 g/m(2)/36h, are not associated with increased disease control in relapsed childhood PBC acute lymphoblastic leukemia.

BACKGROUND Sperm aster organization during bovine and human fertilization requires a paternally-derived centriole that must first disengage from the sperm tail connecting-piece. We investigated the participation of the 26S proteasome in this process. METHODS Proteasome localization and enzymatic activity were studied in normal and pathological human spermatozoa by immunocytochemistry and enzyme-substrate assays. The role of proteasomes during bovine zygote development was investigated using a pharmacological proteasome-inhibitor, MG132, and with anti-proteasome antibodies delivered by Streptolysin O-permeabilization or with the Chariot reagent. Human zygotes discarded after ICSI failures (n = 28) were also examined. RESULTS Proteasomes were localized in the sperm acrosome and connecting-piece, as well as in the pronuclei of bovine and human zygotes. Proteasomal enzymatic activities were decreased in defective human spermatozoa. Disrupted sperm aster formation and pronuclear development were found after pharmacological and immunological block of proteasomes in human/bovine spermatozoa and oocytes, as well as in 28 discarded human post-ICSI fertilization failures. CONCLUSIONS Specific proteasome inhibition disrupts sperm aster formation and pronuclear development/apposition in bovine and human zygotes. Human spermatozoa with defective centriolar/pericentriolar structures have decreased proteasomal enzymatic activity. Release of a functional sperm centriole that acts as a zygote microtubule-organizing center probably relies on selective proteasomal proteolysis. These findings suggest an important role of sperm proteasomes in zygotic development.