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Biomedical subjects

F Mazingue

Publications and source records attributed to F Mazingue.

At least 37 records · Page 2Linked to original sources

[Vertebral compression revealing acute lymphoblastic leukemia].

BACKGROUND: Vertebral compression is rarely the first manifestation of acute leukemia (AL) in children. CASE REPORT: Three children, 13, 4 and 13 years of age respectively, suffered from recent and persistent back pain. The first patient was considered as having psychosomatic problems despite thrombocytopenia at the first examination. The second patient was also pale with hematoma on his legs so that AL could be rapidly recognised. An initial diagnosis of Scheuermann disease was proposed for the third patient in whom hemogram was performed due to worsening of his general condition. The three patients had extended vertebral demineralisation on the first X-rays. CONCLUSION: Causes of back pain in children are often organic at this age of life. They must be searched by suitable examinations.

Adolescent↗

Juvenile myelomonocytic leukemia: analyses of treatment results in the EORTC Children's Leukemia Cooperative Group (CLCG).

Forty-six children with juvenile myelomonocytic leukemia (JMML) diagnosed between 1978 and 1993 in 12 centers were retrospectively studied. There is no evidence that any conventional treatment influences the long-term evolution of JMML. Among 28 patients treated without bone marrow transplantation (BMT), 26 died (median survival: 17 months), two are alive, one in complete remission (CR) after intensive chemotherapy. Allogenic BMT is the best treatment: 18 patients underwent BMT, 11 are in CR (at 9, 15, 22, 25, 41, 45, 49, 53, 66, 90 and 108 months). Conditioning regimens using chemotherapy alone may cure some patients (3/6) occasionally despite autologous reconstitution (1/3); if relapse occurs, a second BMT may be curative (2/3). Among the 12 patients conditioned immediately with TBI, six are in CR, one is in relapse, five died (one of them in durable autologus CR from Schwannoma). It is our opinion that splenectomy is of therapeutic value and seems not to have influenced the incidence of infections complications. We found no argument in favor of intensive chemotherapy before conditioning. Results with HLA-matched unrelated donors are satisfactory. One patient relapsed at 4 months after an unrelated BMT and entered a new CR after discontinuation of cyclosporine.

Antineoplastic Combined Chemotherapy Protocols↗

Changes of cerebral biopterin and biogenic amine metabolism in leukemic children receiving 5 g/m2 intravenous methotrexate.

Acute or subacute neurologic disorders can be observed in patients receiving high-dose methotrexate therapy for lymphoblastic leukemia or malignant tumor. Impairment of biopterin metabolism leading to decreased availability of monoamine neurotransmitters has been suggested to explain methotrexate neurotoxicity. To investigate such a mechanism, we have measured prospectively by HPLC the concentrations of total biopterin, homovanillic acid, and 5-hydroxyindolacetic acid in cerebrospinal fluid of 57 children with acute lymphoblastic leukemia. A sequential analysis of cerebrospinal fluid was performed for each patient: cerebrospinal fluid samples were obtained before therapy and after each of the four high-dose methotrexate infusions during the CNS prophylaxis phase. A significant increase of total biopterin concentrations in cerebrospinal fluid was observed after high-dose methotrexate therapy compared with the pretreatment values. No cumulative effect was noted. In contrast, no significant variation of the homovanillic acid and 5-hydroxyindolacetic acid levels was observed in cerebrospinal fluid. However, individual analysis revealed a transient decrease of homovanillic acid and 5-hydroxyindolacetic acid concentrations in cerebrospinal fluid of six children. The increase of total biopterin mimicking that observed in inherited dihydropteridine reductase deficiencies suggests that methotrexate inhibits the regenerating system of biopterin in the brain of patients undergoing high-dose methotrexate therapy.

Adolescent↗

Carboplatin and VP 16 in medulloblastoma: a phase II Study of the French Society of Pediatric Oncology (SFOP).

The purpose of this study is to evaluate the antitumor activity of combination carboplatin and etoposide in measurable medulloblastoma. From January '89 to January '92, 26 patients with medulloblastoma were included in a multicentric phase II study of 2 courses of carboplatin 160 mg/m2/d day 1 to day 5 and VP16 100 mg/m2/d day 1 to day 5. Median age was 10 years (19 months-14.5 years). First treatment was surgery alone in 1 patient, surgery + radiotherapy in 4 patients, surgery + chemotherapy in 2 patients less than 3 years old, surgery + radiotherapy + chemotherapy in 19 patients ("8 drugs in 1 day" based:17, SIOP I:1, SIOP II:1). Previous treatment included cisplatin (20 cases), carboplatin (1 case), and VP16 (7 cases). Measurable disease was evaluated by CT scan, MRI or myelogram and CSF. Response rate (RR) was 72 +/- 10%:8 complete responses (CR), 10 partial responses (PR), 1 objective effect (OE), 6 progressive disease (PD), 1 non-evaluable. Thirty-six courses were evaluated for toxicity. Median duration of WHO grade 4 neutropenia was 8 days (0-23). One patient died at day 18 after the first course because of diffuse haemorrhage during septic aplasia. Five other non-life-threatening septicemias were recorded. Median number of platelet transfusions was 1 (0-4). One child who had achieved a PR after two courses died from CNS bleeding after the third course. This drug combination achieves a high response rate in childhood medulloblastoma. Severe toxicity has been mainly encountered in previously heavily treated patients. Tolerance may be acceptable in newly diagnosed children, but careful hematological follow-up and platelet transfusional support are definitely mandatory.

Adolescent↗

Improved survival for acute lymphoblastic leukaemia in infancy: the experience of EORTC-Childhood Leukaemia Cooperative Group.

Out of 744 newly diagnosed ALL children under the age of 18 years treated according to the EORTC-CLCG protocols 58831 and 58832, 28 (4%) were infants less than 1 year of age. An elevated risk factor, which takes into account the sizes of the liver and spleen and the number of circulating blasts, was present in 25 cases. Most patients had non-common ALL. Among 15 patients studied by cytogenetics, nine present chromosomal abnormalities, six of them having a t(4;11) translocation. Complete remission was achieved in 86% of cases. One patient died in complete remission of therapy-related infection. The overall EFS is 43%. It is not statistically different in very young infants as compared to infants older than 6 months. Except for patients with AUL or with t(4;11) translocation, a continuous complete remission rate above 50% can be achieved with a median follow-up of 4 years. The results obtained in infant ALL with EORTC-CLCG protocols are currently better than those obtained with some other protocols, but remains inferior when compared to the ones obtained in older children. Thus, further improvements are needed and should be evaluated in large cooperative trials.

Age Factors↗

Cerebrospinal fluid drug levels of leukemic children receiving intravenous 5 g/m2 methotrexate.

A multicenter prospective study was conducted in 114 children with acute lymphoblastic leukemia receiving 4 intravenous methotrexate (MTX) courses (5 g/m2 as a 24 hour-infusion) to determine the diffusion of MTX in cerebrospinal fluid (CSF) and to correlate the drug levels to central nervous system (CNS) relapse occurrence. Serum and CSF levels were measured at the end of 446 MTX courses. A significant correlation was found between CSF and serum MTX concentration. CSF MTX level was greater than 1 mumol/l in 66% of the courses. Twelve patients (11%) failed to achieve this potentially cytotoxic drug level at the end of the 4 consecutive MTX courses: only one CNS relapse was observed and the mean age of these children was lower than that of the others. To date 9 (7.8%) children had CNS relapse and no difference was observed in terms of CSF MTX levels when compared to data of children free of CNS relapse. With a median follow up of 32 months, pharmacokinetic data during high-dose MTX therapy do not seem to be an exclusive predictive factor of CNS relapse.

Adolescent↗

2,4-diamino-7-hydroxy-pteridines in biological fluids of patients on high-dose methotrexate.

Concentrations of 2,4-diamino-7-hydroxy-pteridines in plasma and cerebrospinal fluid (CSF) are reported for the 0.5-8 g/m2 dose range of methotrexate in children with acute lymphoblastic leukemia or non-Hodgkin's lymphoma. This experiment has revealed that: (1) there is a wide inter-individual but relatively narrow intra-individual variability of the maximal concentrations of 2,4-diamino-7-hydroxy-pteridines in plasma during consecutive methotrexate cycles; (2) the increase in the level of the metabolites in plasma was related to increments of the methotrexate dose, but not above 5 g/m2: this can be explained by a saturable conversion of methotrexate to 2,4-diamino-7-hydroxy-pteridines; (3) significant correlations were found between simultaneous values of 2,4-diamino-7-hydroxy-pteridines in plasma and CSF; (4) the formation of 2,4-diamino-7-hydroxy-pteridines did not depend on the ages of patients receiving the same dose of methotrexate. The presence of these compounds in plasma and CSF in significant amounts creates the potential for a number of competitive interactions with pteridine-dependent metabolism which may open up new possibilities for understanding the metabolic side-effects of methotrexate therapy.

Adolescent↗

Cerebrospinal fluid neopterin levels in children with central nervous system leukemia.

Cerebrospinal fluid (CSF) neopterin levels were determined by high-pressure liquid chromatography in 48 normal children and in 15 children with meningeal relapse of hematologic malignancies (13 acute lymphoblastic leukemia and 2 high-grade lymphomas). When meningeal relapse was diagnosed, all patients had CSF neopterin levels higher than mean normal value +2 standard deviations. No significant correlation between the blast count in the CSF and neopterin levels was observed. CSF data before relapse were available in 10 children: the neopterin values at relapse were significantly higher than values observed at diagnosis. In 3 patients, elevated neopterin levels preceded the occurrence of neurologic signs and the detection of blast cells in CSF by 15 to 30 days. In the absence of infection, the rise of CSF neopterin levels in patients with hematologic malignancies indicates an active phase of the disease. This could reflect a cell-mediated immunologic process induced by malignant cells. The measurement of CSF neopterin should be helpful in the monitoring of patients to detect early meningeal relapse.

Adolescent↗

Expression of P-glycoprotein restricted to normal cells in neuroblastoma biopsies.

Immunohistological detection of P-glycoprotein (P-gp) with monoclonal antibody C219 was performed on serial sections of 37 neuroblastoma specimens representative of the different forms of the disease, from stage 1 ganglioneuroma to stage 4 neuroblastoma. Malignant cells, irrespective of their degree of maturation varying from neuroblasts to ganglion cells, were negative on all specimens. The expression of P-glycoprotein was detected in nine specimens, but it was restricted to normal cells within the tumour. In four specimens, C219 reacted with normal infiltrating cells in the stroma (i.e. monocytes, histiocytes or fibroblasts) representing 5 to 10% of the total population within the section; in three specimens, the residual adrenal gland was strongly positive, and in two ganglioneuromas, a weak reactivity of C219 was observed on a few satellite cells and schwann cells. Three of 15 biopsies obtained at diagnosis contained normal P-gp positive cells: two were classified as stage 1 ganglioneuromas; one was a typical stage 4 composite tumours with positive histiocytes and fibroblasts in the well-differentiated counterpart. Six of 22 biopsies obtained after patients had received our current protocol of chemotherapy contained normal P-gp positive cells: five were partially differentiated and necrotic under the effect of chemotherapy; only one positive specimen was classified as undifferentiated neuroblastoma. Among negative specimens from previously treated patients, one was obtained from a patient in relapse after high-dose chemotherapy and ABMT, two were obtained from patients who had not responded to induction therapy, and six from patients in partial remission after induction therapy. The clinical evolution was very similar in both groups of patients with P-gp negative or positive biopsies. These findings suggest that the quantitative assessment of MDR RNA by northern blotting on fresh homogenates is likely to overestimate its expression on neuroblastoma cells, and that the mechanism of chemoresistance in widespread neuroblastoma is less likely to be associated with P-gp expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

[High-dose methotrexate and hyperphenylalaninemia].

The occurrence of increased levels of blood phenylalanine after therapeutic administration of folate analogues has been occasionally reported and attributed to the inhibition of dihydropteridine reductase, an enzyme maintaining the cofactor of phenylalanine hydroxylase in its active tetrahydrogenated form (tetrahydrobiopterin). To study further this metabolic effect, 46 patients receiving high dose methotrexate (5 to 8 g/m2) infusions have been studied. Significant increase in serum phenylalanine was observed in 95% of methotrexate cycles, occurring at the end of infusion. In contrast to the large inter-individual variations, maximal phenylalanine concentrations were of the same magnitude in each individual, suggesting individual predispositions. The hypothesis of an inhibition of dihydropteridine reductase by methotrexate was supported by the parallel course of serum biopterin and phenylalanine levels, but in some way contradicted by the rapid return to baseline values of both, 24 hours after the end of methotrexate infusion. This transient and often moderate hyperphenylalaniemia is probably harmless except if it reflects a more general inhibition of pteridine-dependent hydroxylases. Especially, such an inhibition of cerebral tyrosine- and tryptophan-hydroxylase activities might be the reason for transient neurological disturbances observed in some patients on high-dose methotrexate treatment.

Adolescent↗

Severe combined immunodeficiency syndrome associated with autosomal recessive familial multiple gastrointestinal atresias: study of a family.

Hereditary multiple atresias involving the gastrointestinal tract from pylorus to rectum are the most unusual form of intestinal atresia; the type of inheritance was suggested to be autosomal recessive. The inheritance of the severe combined immunodeficiency syndrome can be autosomal recessive or X-linked. We report on 3 sibs with multiple-level intestinal atresias. One sib had severe combined immunodeficiency syndrome and clinical histories of the other 2 sibs strongly suggested a congenital immunodeficiency syndrome. The parents of those children were healthy and nonconsanguineous. To our knowledge, this is the first report of the association of multiple gastrointestinal atresias and immunodeficiency which appears to have an autosomal recessive pattern of transmission. Our family report suggests that, in the presence of multiple gastrointestinal atresias, attention should be given to possible associated immunological disorders.

Abnormalities, Multiple↗

[Non-traumatic circumscribed myositis ossificans in the femoral region].

The authors report the main clinical and radiographic aspects of non-traumatic circumscribed myositis ossificans in a 12 year-old child. These observations provide useful information for making a diagnosis. CT scan showed the presence of two distinct areas, a lucent central area and a dense outer area whose appearance suggest the presence of calcium. The main differential diagnosis concerned tumors in the soft bone tissue which necessitated regular clinical and paraclinical follow-up.

Child↗

[Precocious pseudo-puberty in granulosa cell tumor in children less than 1 year old. 2 cases].

Two cases of isosexual precocity in relation to granulosa cell tumor in 2 girls aged 6 and 9 months respectively are described. In the two cases clinical and biological signs of hyperoestrogenemia were found but in one, acute signs of tumoral rupture were the first symptom. Histologically, the two classical subtypes were found: macrofollicular ("adult" type) and "juvenile". These two children are alive without any sign of recurrence with a follow up of 12 and 18 months. The occurrence of granulosa cell tumors in such young girls seems extremely rare.

Estradiol↗

[Monocyte-macrophage activation syndrome].

The activation of macrophage after stimulations (infectious, immunologic, irritative) is the ability of this cell to destroy intracellular bacteria and tumoral cells. Activated macrophage is characterized by morphological, biological and immunological properties and by its phagocytosis ability. The activation of macrophage can explain most of the signs encountered in several diseases: familial hemophagocytic lymphoreticulosis, accelerated phases of some immunodeficiencies but also protection of the organism against infectious diseases, immunological tolerance and antitumoral immunity.

Animals↗