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Abstract
The expression of the Wilms' tumor gene (wt1) was detected in various tissues during embryonic development. Mutations in the wt1 gene probably play an important role in certain tumors, e.g. the Wilms' tumor. Furthermore the expression of wt1 gene was found in some human leukemias. In the present study we investigated the expression of wt1 gene in several types of childhood leukemia by reverse transcriptase-polymerase chain reaction. Bone marrow or peripheral blood of 61 pediatric patients (48 at initial diagnosis, 13 at first or second relapse) were analyzed. wt1 gene expression was detected in 35/48 patients (73%) with newly diagnosed leukemias and in 12/13 cases (92%) who had suffered from relapse. The expression levels were higher for AML than for ALL. The frequency of wt1 expression in different subtypes of acute leukemia was compared with results found in adult patients. Our results show that the frequency of wt1 gene expression in acute childhood leukemias is similar to previous data reported for adults.
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Abstract
PURPOSE To identify the long-term sequelae of therapy for malignant germ cell tumors (GCTs). PATIENTS AND METHODS Between 1980 and 1998, 1,132 patients were prospectively enrolled onto the German nontesticular GCT studies. A total of 442 patients received chemotherapy using combinations of the drugs cisplatin, ifosfamide, etoposide, vinblastine, and bleomycin, and 174 patients were treated with a combination of chemotherapy and radiotherapy. Median follow-up duration was 38 months (range, 6 to 199 months). RESULTS Six patients developed therapy-related acute myelogenous leukemia (t-AML). There was no t-AML among patients treated with surgery (n = 392) or radiotherapy only (n = 124). The Kaplan-Meier estimates of the cumulative incidence (at 10 years) of t-AML were 1.0% for patients treated with chemotherapy (three of 442) and 4.2% for patients treated with combined chemotherapy and radiotherapy (three of 174). Notably, four of these six patients had been treated according to a standard protocol with modest cumulative chemotherapy doses. Five patients had received less than 2 g/m(2) epipodophyllotoxins, and four patients had received less than 20 g/m(2) ifosfamide. Four patients presented with AML, two with myelodysplasia in transformation to AML. In five patients, cytogenetic aberrations were found, four of which were considered characteristic for t-AML. Four patients died despite antileukemic therapy. One patient is alive but suffered a relapse of his GCT, and one patient is alive and well. No secondary solid neoplasm was observed. CONCLUSION In patients with AML after treatment for GCT, several pathogenetic mechanisms must be considered. AML might evolve from a malignant transformation of GCT components without any influence of the chemotherapy. On the other hand, the use of alkylators and topoisomerase II inhibitors is associated with an increased risk of t-AML. Future studies will show if the reduction of treatment intensity in the current protocol reduces the risk of secondary leukemia in these patients.
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Cerebral venous sinus thrombosis in children with acute lymphoblastic leukemia carrying the MTHFR TT677 genotype and further prothrombotic risk factors. KLINISCHE PADIATRIE 1999; 211:211-4. [PMID: 10472552 DOI: 10.1055/s-2008-1043790] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND The present study was designed to prospectively evaluate the role of prothrombotic risk factors in leukemic children treated according to the ALL-BFM 90/95 study protocols with respect to the onset of cerebral venous sinus thrombosis. PATIENTS 317 consecutive leukemic children aged 6 months to 18 years were enrolled in this study. 288 of the 317 patients were available for thrombosis-free survival analysis. RESULTS In 17 (5.9%) of these 288 patients cerebral venous sinus thrombosis occurred. The overall event-free survival of thrombosis in the central nervous system in patients with at least one prothrombotic defect (n = 12) was significantly reduced compared with patients without a prothrombotic defect (p < 0.0001). 15 patients showed acute clinical symptoms at onset of cerebral venous sinus thrombosis, two were asymptomatic. Three of the 17 patients affected (17.6%) died directly associated with the thrombotic event during induction therapy, the remaining 14 patients did not show prolonged clinical symptoms. CONCLUSIONS Prothrombotic risk factors should be included in a screening program in ALL children treated according to the BFM study protocols. Further prospective studies are recommended to establish adequate prophylactic anticoagulant treatment during ALL (BFM) polychemotherapy.
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Abstract
Aphidicolin is a fungal derived tetracyclic diterpene antibiotic. It is selectively toxic for neuroblastoma (NB) cells in vitro but has no significant effects on the viability of normal human cells and a variety of other tumor entities. We evaluated the antitumoral effects of the water soluble ester aphidicolin glycinate (AphiG) on established human NB xenografts from UKF-NB-3 cells in athymic (nude) mice. Furthermore, we explored the efficacy of direct intraneoplastic and systemic delivery of AphiG. Systemic administration of AphiG (60 mg/kg intraperitoneally, twice per day on 10 consecutive days) significantly suppressed tumor growth but was not able to induce any cures. In contrast, intratumoral AphiG injections (60 or 40 mg/kg/twice a day for 4 days) induced complete tumor regression. Two weeks after the end of treatment no tumor cells were microscopically detectable. Animals were free of tumor for more than 90 days. Histologic examination of inner organs and bone marrow did not reveal any apparent toxic effects of AphiG. These data strongly indicate that AphiG deserves further evaluation as a specific treatment for neuroblastoma.
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Prospective evaluation of the thrombotic risk in children with acute lymphoblastic leukemia carrying the MTHFR TT 677 genotype, the prothrombin G20210A variant, and further prothrombotic risk factors. Blood 1999; 93:1595-9. [PMID: 10029588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
The reported incidence of thromboembolism in children with acute lymphoblastic leukemia (ALL) treated with L-asparaginase, vincristine, and prednisone varies from 2.4% to 11.5%. The present study was designed to prospectively evaluate the role of the TT677 methylenetetrahydrofolate reductase (MTHFR) genotype, the prothrombin G20210A mutation, the factor V G1691A mutation, deficiencies of protein C, protein S, antithrombin, and increased lipoprotein (a) concentrations in leukemic children treated according to the ALL-Berlin-Frankfurt-Muenster (BFM) 90/95 study protocols with respect to the onset of vascular events. Three hundred and one consecutive leukemic children were enrolled in this study. Fifty-five of these 301 subjects investigated had one established single prothrombotic risk factor: 20 children showed the TT677 MTHFR genotype; 5 showed the heterozygous prothrombin G20210A variant; 11 were carriers of the factor V G1691A mutation (heterozygous, n = 10; homozygous, n = 1); 4 showed familial protein C, 4 protein S, and 2 antithrombin type I deficiency; 9 patients were suffering from familially increased lipoprotein (a) [Lp(a)] concentrations (>30 mg/dL). In addition, combined prothrombotic defects were found in a further 10 patients: the FV mutation was combined with the prothrombin G20210A variant (n = 1), increased Lp(a) (n = 3), protein C deficiency (n = 1), and homozygosity for the C677T MTHFR gene mutation (n = 1). Lp(a) was combined with protein C deficiency (n = 2) and the MTHFR TT 677 genotype (n = 2). Two hundred eighty-nine of the 301 patients were available for thrombosis-free survival analysis. In 32 (11%) of these 289 patients venous thromboembolism occurred. The overall thrombosis-free survival in patients with at least one prothrombotic defect was significantly reduced compared with patients without a prothrombotic defect within the hemostatic system (P <.0001). In addition, a clear-cut positive correlation (P <.0001) was found between thrombosis and the use of central lines. However, because the prothrombotic defects diagnosed in the total childhood population studied were all found within the prevalences reported for healthy Caucasian individuals, the interaction between prothrombotic risk factors, ALL treatment, and further environmental factors is likely to cause thrombotic manifestations.
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Dexmedetomidine modulates cardiovascular responses to stimulation of central nervous system pressor sites. Anesth Analg 1999; 88:617-24. [PMID: 10072017 DOI: 10.1097/00000539-199903000-00029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
UNLABELLED Halothane attenuates the alterations in arterial pressure (BP) and heart rate (HR) produced by central nervous svstem (CNS) stimulation. We examined the effects of the alpha2-adrenergic agonist dexmedetomidine, with and without halothane, on cardiovascular regulation during CNS pressor site stimulation in chronically instrumented cats. Stimuli trains via bipolar stimulating electrodes in the hypothalamus and reticular formation elicited pressor responses. Dexmedetomidine-induced (15 microg/kg PO) bradycardia was greater in the presence of halothane. CNS stimulation increased BP and HR, which were dose-dependently attenuated by halothane (hypothalamic stimulation 71 +/- 9 mm Hg at control, 25 +/- 5 and 15 +/- 3 mm Hg at 1.0% and 1.5% halothane, respectively). Although dexmedetomidine alone did not alter pressor responses, halothane plus dexmedetomidine attenuated pressor responses in a potentially synergistic fashion (hypothalamic stimulation 67 +/- 8 mm Hg at control, 2 +/- 1 and 1 +/- 0.4 mm Hg at 1.0% and 1.5% halothane, respectively). These results suggest differences in the disruptive effects of CNS-mediated cardiovascular responses by halothane and dexmedetomidine, and that dexmedetomidine has an anesthetic-sparing effect on these CNS-mediated cardiovascular control mechanisms, potentiating the depressant effect of halothane. IMPLICATIONS A new potential anesthetic adjunct, dexmedetomidine, does not attenuate brain-mediated increases in blood pressure, but the combination of dexmedetomidine and the anesthetic halothane acts to modulate central cardiovascular responses.
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Azidothymidine resistance of H9 human T-cell lymphoma cells is associated with decreased sensitivity to antitumor agents and inhibition of apoptosis. Int J Mol Med 1998; 2:685-91. [PMID: 9850737 DOI: 10.3892/ijmm.2.6.685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Biology of HIV-1 associated neoplasias is modulated by viral and host factors. In addition the development of tumors and their response to therapy may be further influenced by long-term treatment of HIV-1 patients with nucleoside analogs such as AZT (3'-azido-3'deoxythymidine), ddI (2',3'-dideoxyinosine), ddC (2',3'-dideoxycytidine), d4T (2',3'-didehydro-2'3'-dideoxythymidine), and 3TC [(-)-beta-L-2',3'-dideoxy-3'-thiacytidine] alone or in combination. As these compounds can trigger mechanisms involved in chemoresistance, we tested whether prolonged in vitro treatment of H9 cells (T-cell lymphoma) with AZT alters sensitivity of lymphoma cells to antitumor agents used for AIDS-associated malignancies. H9 cells grown for more than two years in medium containing 250 microM AZT developed resistance to the toxic effects of AZT while retaining sensitivity for other nucleoside analogs including ddC or cytosine arabinoside (ARA-C). These cells designated H9rAZT250 were 2 to 10-fold less sensitive to the toxic effects of antitumor agents, including cisplatin (CDDP), vincristine (VCR), doxorubicin (DOX) and etoposide (VP-16), when compared with parental H9 cells. The resistance of H9rAZT250 cells to antitumor agents was associated with inhibition of apoptosis as demonstrated by ultrastructural investigations and DNA-fragmentation assay (ELISA). The expression of the antiapoptotic gene bcl-2 was increased in H9rAZT250 cells while expression of other genes involved in the regulation of apoptosis such as c-myc, p53 and Fas was not changed. These results demonstrate that prolonged in vitro treatment of H9 lymphoma cells with AZT results in the development of resistance to antitumor agents in association with inhibition of apoptosis and increased expression of bcl-2. Therefore AZT long-term treatment of some HIV-1 patients with malignancies may have affected behavior of tumor cells including response to therapy.
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TEL-AML1 fusion transcript in relapsed childhood acute lymphoblastic leukemia. The Berlin-Frankfurt-Münster Study Group. Blood 1998; 91:1716-22. [PMID: 9473238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The cryptic translocation t(12;21)(p13;q22) has been recently recognized as the most common genetic rearrangement in B-lineage childhood acute lymphoblastic leukemia (ALL). The resulting fusion transcript, termed TEL-AML1, has been associated with an excellent prognosis at initial ALL diagnosis. Hence, we postulated that the incidence of TEL-AML1 fusion should be lower in patients with ALL relapse. To address this assumption and to investigate the prognostic significance of TEL-AML1 expression in relapsed childhood ALL, bone marrow samples of 146 children were analyzed by reverse-transcriptase (RT)-polymerase chain reaction (PCR). All children were treated according to Berlin-Frankfurt-Münster (BFM) ALL relapse trial protocols (ALL-REZ BFM 90-96). Their clinical features and outcome were compared with those of 262 patients who could not be tested due to lack of bone marrow samples. Thirty-two of 146 children with relapsed ALL were TEL-AML1-positive. Four of the negative patients had T-lineage and nine Philadelphia chromosome (Ph)-positive leukemia. Thus, the incidence of TEL-AML1 in relapsed Ph1-negative, B-cell precursor ALL is 32 of 133 (24%). The 32 TEL-AML1-positive and 101 negative patients differed significantly with respect to duration of last remission (42.5 v 27 months; P = . 0001) and age at initial diagnosis (53.5 v 74 months; P = .0269). At a median follow-up time of 21.5 months, children positive for TEL-AML1 had a significantly (P = .0011) higher probability of event-free survival (EFS; 0.79 v 0.33). The predominant majority of patients had been treated for initial ALL according to German multicenter BFM (108 of 133) or Cooperative ALL study group (CoALL) (19 of 133) frontline protocols. The comparison of tested and not-tested (N = 262) patients showed no significant difference. TEL-AML1 positivity predicted a favorable short-term outcome; long-term results are unknown. Screening for TEL-AML1 should become routine at relapse diagnosis and might be used for therapy stratification in future trials.
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Persistent human cytomegalovirus infection induces drug resistance and alteration of programmed cell death in human neuroblastoma cells. Cancer Res 1998; 58:367-72. [PMID: 9443419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Infection with human cytomegalovirus (HCMV) is a common and generally asymptomatic affection in childhood. Its role in neuroblastoma (NB) patients has not yet been elucidated. As evidence grows that HCMV interacts with apoptotic signaling due to the interaction of HCMV gene products with cellular proteins of apoptotic pathways, we used human NB cell line UKF-NB-2 persistently infected with HCMV strain AD169 to study the effects of long-term HCMV infection on programmed cell death of neuroectodermal tumor cells. The cells designated UKF-NB-2AD169 continued to produce infectious virus in successive subcultures over a period of more than 1 year. Up to 20% of cells expressed viral genes or produced infectious virus after initiation of infection. UKF-NB-2AD169 cells were significantly less sensitive to the cytotoxic agents cisplatinum and etoposide than parental (noninfected) UKF-NB-2 cells. These effects were associated with decreased ability of UKF-NB-2AD169 cells to undergo apoptosis and continuous viral replication. UKF-NB-2AD169 cells showed increased levels of antiapoptosis Bcl-2 protein (up to 12-fold), whereas expression of p53 and c-myc was not changed. Treatment of UKF-NB-2AD169 cells with ganciclovir, abolishing virus production, reestablished sensitivity to chemotherapy, lowered Bcl-2 expression, and facilitated inducibility of apoptosis to the level of the parental cell line. The results demonstrate that persistent HCMV infection confers resistance to cytotoxic agents on neuroectodermal tumor cells and protects from apoptosis, probably due to increased levels of Bcl-2 protein. Hence, it is conceivable that HCMV infection before or during tumorigenesis may contribute in some NB patients to failure of therapy.
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Fluconazole versus nystatin in the prevention of candida infections in children and adolescents undergoing remission induction or consolidation chemotherapy for cancer. J Antimicrob Chemother 1997; 40:855-62. [PMID: 9462438 DOI: 10.1093/jac/40.6.855] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
An open, prospective, randomized pilot study was performed to assess the efficacy and safety of oral fluconazole 3 mg/kg once daily compared with oral nystatin 50,000 units/kg/day in four divided doses in preventing candida infections in 50 children undergoing remission induction or consolidation therapy for cancer. In 21 of 25 fluconazole-treated and 20 of 25 nystatin-treated patients the overall outcome of prophylaxis was clearly successful. Mild and transient oropharyngeal candidosis was observed in two and three patients in the fluconazole and nystatin groups respectively. One patient randomized to fluconazole and two patients randomized to nystatin required empirical treatment with amphotericin B and one patient assigned to fluconazole developed tissue-proven candida colitis. Initially non-colonized patients remained yeast-free throughout treatment with no differences between the two study arms. Initially colonized patients stayed colonized throughout treatment although at the end of the study, more patients randomized to nystatin were still harbouring yeasts (P = 0.05). Almost exclusively, Candida albicans (95%) was isolated. A change in species was observed in one patient in each arm of the study. Candida krusei or Candida glabrata were not encountered. Transient elevations of hepatic transaminases were more common in the fluconazole group, although not statistically significant (28% vs 12%, P = 0.15). Reversible grade I gastrointestinal and skin symptoms were observed in four patients randomized to fluconazole (16 vs 0%, P < 0.05). Fluconazole was as safe and effective as nystatin in controlling yeast colonization and in preventing superficial and invasive candida infections and the empirical use of amphotericin B in children and adolescents undergoing intensive chemotherapy for cancer.
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Differentialdiagnose pulmonaler Infektionen bei Kindern und Jugendlichen mit neoplastischen Erkrankungen. Monatsschr Kinderheilkd 1997. [DOI: 10.1007/s001120050220] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
Sodium valproate (VPA) belongs to the group of simple branched-chain fatty acids and due its anticonvulsive activity is broadly applied in the treatment of epilepsy. We previously showed that VPA is able to induce cellular differentiation, to enhance immunogenicity and to inhibit proliferation of human neuroblastoma (NB) cells in vitro. Furthermore, we demonstrated that VPA inhibits proliferation, enhances neural cell adhesion molecule expression and decreases CD44 expression of human and rat glioma cells in vitro. In the present study we investigated the antitumoral effects of VPA on established human NB xenografts from UKF-NB-3 human NB cells in athymic (nude) mice. When the animals developed s.c. tumors of about 100 mm3 volume they were treated with 400 or 200 mg/kg/day VPA i.p. At the end of the treatment period (40 days) tumor volumes in animals treated with 400 and 200 mg/kg VPA were about 4- (p < 0.0001) and 2-fold (p < 0.0005) smaller than in the saline-treated control group, respectively. Histological examination of the remnant tumors of treated animals revealed induction of differentiation by induction of stroma-rich tumors and nodules that contained elongated NB cells. Pyknotic nuclei and apoptotic bodies indicated induction of apoptosis. We conclude that VPA is able to abrogate NB growth in vivo and may therefore be useful in the treatment of NB patients.
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[Management of children with oncologic illnesses. Cooperation between the family physician and the clinic]. ZEITSCHRIFT FUR ARZTLICHE FORTBILDUNG UND QUALITATSSICHERUNG 1997; 91:267-75. [PMID: 9312432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Malignancies in infancy and childhood represent rare diseases which in addition distribute to many different entities. Therapy is almost exclusively carried out according to protocols of cooperative multicenter studies which are performed by specialized children hospitals. The intensity of the therapy and, thus, the potential hazards require profound experience in the field. The intention of the therapy is curative in the majority of the cases. The family physician plays an important role in the early diagnosis of the disease and long-term care. The therapy itself is mostly restricted to institutions which are adequately equipped. These institutions will provide ambulatory care as well. The care in final stage causes particular challenges. A substantial part of the parents and children opt for care at home. An increasing engagement of the family physicians in this field is highly appreciated.
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Differential diagnosis based on immunological-phenotyping in suspected malignant bone marrow involvement in childhood. Pediatr Hematol Oncol 1997; 14:29-41. [PMID: 9021811 DOI: 10.3109/08880019709030882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The diagnostic value of immunophenotyping (IP) as a first-line diagnostic method in diseases that infiltrate the childhood bone marrow (BM) or mimic infiltrated BM was examined. Two hundred and fifty unselected BM samples from 250 children suspected to have a malignancy infiltrating their BM were evaluated by means of IP and conventional morophological-cytochemical (MC) studies. We applied the alkaline phosphatase anti-alkaline phosphatase method for IP using a panel of monoclonal antibodies (Mabs) against leukocyte-associated antigens, neuroectodermal antigens, and intermediate filament antigens. Four cases of neuroblastoma, two cases of Ewing sarcoma, and one case of rhabdomyosarcoma were diagnosed by IP but not by MC studies. In nine cases of acute leukemia bone marrow blasts could not be ascribed to a specific lineage on the basis of blast morphology or histochemistry. Eight samples without morphological evidence of malignant infiltration revealed an increased percentage of immature B cell precursors (CD10+, TdT+) suggesting acute lymphoblastic leukemia. None of these children has developed malignant lymphoproliferative disease. Our data suggest that the immunological evaluation of BM in childhood is highly capable of discriminating between different malignant populations but it does not recognize malignancy and therefore supplements but cannot replace conventional methods for diagnosis.
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Thrombolyse bei Neugeborenen und Säuglingen. Hamostaseologie 1996. [DOI: 10.1055/s-0038-1656664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
ZusammenfassungSechzehn Kinder (3 Tage bis 11 Monate, Median 6 Wochen) mit thrombotischen oder embolischen Verschlüssen großer Gefäße wurden mit rt-PA behandelt. Betroffen waren die Nierenvenen beider Seiten oder eine Nierenvene und die V. cava inferior (n = 8), die V. cava superior (n = 3), beide Nierenvenen, die V. cava inferior und die Aorta (n = 1), der linke Ventrikel (n = 1), isoliert die Aorta (n = 1), die A. femoralis (n = 1) und die V. portae (n = 1). Zehn der 16 Okklusionen waren Katheter-assoziiert. Die Thrombolyse wurde mit einem Bolus von 0,1-0,2 mg/kg rt-PA eingeleitet und mit einer Dauerinfusion fortgeführt (0,8-2,4 [-9] mg/kg/24 h). Heparin in niedriger Dosis (100 IE/kg/24 h) begleitete die Therapie. Unmittelbar nach Beendigung der Thrombolyse erfolgte eine Voll-heparinisierung (aPTT 1,5- bis 2fache der Norm). Fünf Patienten erhielten rt-PA lokoregionär durch den liegenden Katheter, die anderen systemisch. Bei 13 Patienten gelang eine vollständige Rekanalisierung, bei zweien eine partielle. Bei einem Patient mußte die Behandlung abgebrochen werden. Zwei Patienten erlitten eine spätere Reokklusion des betroffenen Gefäßes. Blutungen verzeichneten wir bei 3 Patienten, alle aus frischen Punktionsstellen. Die Resultate rechtfertigen die Durchführung einer systematischen multizentrischen Therapiestudie.
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Abstract
Arterial blood pressure and heart rate changes after afferent somatic sensory nerve stimulation are termed the "somatosympathetic reflex" (SSR). Inhibition of the SSR may partially represent an antinociceptive action. This investigation examined the actions of the volatile anesthetic, desflurane, on the SSR evoked by peripheral nerve stimulation. Rats anesthetized with alpha-chloralose (50 mg/kg) and urethane (500 mg/kg) were mechanically ventilated and cannulated with arterial and venous catheters for monitoring arterial pressure and for fluid administration, respectively. The sciatic (n = 7) or tibial (n = 6) nerves were isolated and stimulated at one, two, and four times the voltage threshold required to elicit a change in systemic hemodynamics. These cardiovascular responses were recorded before, during, and after varying concentrations of desflurane, 1.8% (0.25 minimum alveolar anesthetic concentration [MAC]), 3.6% (0.5 MAC), 7.2% (1.0 MAC), and 10.8% (1.5 MAC). Desflurane decreased arterial pressure at 1.0 and 1.5 MAC and heart rate (at more than 0.5 MAC) compared to baseline levels. Tibial nerve stimulation decreased mean arterial pressure (MAP) with no consistent changes in heart rate. Desflurane significantly attenuated this depressor response to tibial nerve stimulation (MAP decrease: control; -20 +/- 2 mm Hg versus 1.0 MAC desflurane; -6 +/- 4 mm Hg). The increases in MAP after sciatic nerve stimulation were also significantly inhibited by increasing concentrations of desflurane. At more than 0.5 MAC desflurane, the pressor response to sciatic nerve stimulation was significantly converted to a depressor response in four of seven rats (MAP: control; increase 24 +/- 2 mm Hg versus 1.0 MAC desflurane; decrease -2 +/- 4 mm Hg). Sciatic nerve stimulation also elicited increases in heart rate which were significantly attenuated by desflurane (control; 37 +/- 6 bpm versus 1.5 MAC desflurane; 0 +/- 2 bpm). These findings demonstrate that desflurane produces dose-dependent cardiovascular depression in rats and, despite previous reports of sympathoexcitation, desflurane significantly attenuated both excitatory and inhibitory types of SSR. The results of this study also support a potential antinociceptive action for this anesthetic.
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Temperature-gradient-double-crucible method for high-temperature solution growth. CRYSTAL RESEARCH AND TECHNOLOGY 1995. [DOI: 10.1002/crat.2170300109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Formation of cytosine arabinoside-5'-triphosphate in different cultured lymphoblastic leukaemic cells with reference to their drug sensitivity. Eur J Cancer 1995; 31A:209-14. [PMID: 7718327 DOI: 10.1016/0959-8049(94)00412-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The accumulation of intracellular cytosine arabinoside-5'-triphosphate (Ara-CTP) is determined in five lymphoblastic cell lines: Molt 4, H9 and three newly established cell lines from paediatric patients, KFB-1, KFB-2, KFT-1. The cell lines KFB-1 and KFB-2 are B-lymphoblastic (B-ALL), the others are T-lymphoblastic leukaemic cells (T-ALL). The Ara-CTP levels were compared with the sensitivity of the cells to Ara-C. The cells were incubated at different concentrations (100 nM-100 microM) of Ara-C for 4 h or incubated for variable times (30 min-11 h) at 0.1, 1 and 10 microM Ara-C to form Ara-CTP. The Ara-CTP-concentrations were measured by high pressure liquid chromatography (HPLC). To determine the sensitivity of the cells to Ara-C, the MTT colorimetric-assay was used. The studies indicate that different B- and T-lymphoblastic leukaemia cell lines accumulate Ara-CTP to a markedly different extent. Ara-CTP plateau levels and sensitivity of the cells to Ara-C correlated well in four of the five cells lines studied.
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Abstracts. J Neurooncol 1994. [DOI: 10.1007/bf01070874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Enhanced thrombin generation, P-von willebrand factor, P-fibrin D-dimer and P-plasminogen activator inhibitor 1: Predictive for venous thrombosis in asparaginase-treated children. ACTA ACUST UNITED AC 1994. [DOI: 10.1016/0268-9499(94)90248-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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[High dosage methotrexate in combination with "8 in 1" in therapy of pediatric grade III/IV brain tumors]. KLINISCHE PADIATRIE 1992; 204:72-7. [PMID: 1583854 DOI: 10.1055/s-2007-1025326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
20 patients with malignant brain tumors in childhood were treated according to a regimen which included initial surgery, preradiation chemotherapy and subsequent irradiation. The chemotherapy consisted of alternating cycles of high-dose methotrexate (12 g/m2) and "8 drugs in 1 day" (Bleyer, 1983). Each cycle was to be given up to six times, as tolerated. The diagnoses were medulloblastoma in 10 cases, astrocytoma in 5 cases, ependymoma and PNET in 2 patients each, and malignant mesenchymoma in 1 case. 15 patients were previously untreated, 5 patients experienced relapse after a different first line therapy and a longer time interval. 8 patients are in continuous complete remission for 13 to 54 months. The toxicity upon the bone marrow, the kidney and the inner ear was tolerable. Long lasting emesis contributed a marked problem to the patients but did not cause abbreviation of the therapy. The neurotoxicity was notably mild. Three episodes of generalized seizures were seen without subsequent sequelae, four cases of peripheral neuropathy were attributable to vincristine. A leukoencephalopathy was neither detected on clinical grounds nor on neuroradiological imaging. Therapy related deaths were not seen. We conclude that the combination of HD-MTX and "8 in 1" markedly contributes to the intensification of the chemotherapy for malignant brain tumors in childhood. In the setting as preradiation chemotherapy the toxicity is tolerable.
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74
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Fatal haemoptysis associated with invasive pulmonary aspergillosis treated with high-dose amphotericin B and granulocyte-macrophage colony-stimulating factor (GM-CSF). Mycoses 1992; 35:67-75. [PMID: 1435849 DOI: 10.1111/j.1439-0507.1992.tb00822.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Opportunistic pulmonary infections are a leading cause of morbidity and mortality in patients with chemotherapeutically treated neoplasias. With increasingly aggressive cytotoxic regimens causing prolonged neutropenia, the risk of systemic mycoses and in particular of invasive pulmonary aspergillosis has increased. We review the case of a 10-year-old child suffering from relapsed lymphoblastic leukaemia and from high-dose amphotericin B-treated invasive pulmonary aspergillosis acquired during long-standing neutropenia in the initial phase of remission induction chemotherapy. The patient died in remission after GM-CSF-induced bone marrow recovery and clinical and radiological improvement with stable plasmatic coagulation and normal thrombocyte count. Peracute massive pulmonary bleeding caused by the simultaneous arrosion of a greater pulmonary artery and a lobar bronchus by a liquefactive fungal focus was responsible. In patients with chemotherapeutically induced neutropenia and invasive aspergillosis, bone marrow recovery may lead to the liquefaction of pulmonary foci, and, in view of the well-known vasotropic nature of the infection, to a potentially lethal arrosion bleeding. With the emerging use of colony-stimulating factors for shortening and overcoming neutropenia, this so far rare complication may become of increasing importance.
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75
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Thrombolytic therapy in children suffering from malignancies — urokinase versus RT-PA. Thromb Res 1992. [DOI: 10.1016/0049-3848(92)90714-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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76
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RT-PA therapy in the first year of life — A new thrombolytic regimen in children. Thromb Res 1992. [DOI: 10.1016/0049-3848(92)90588-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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77
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Local thrombolytic therapy with RT-PA in children — a new therapeutic approach. Thromb Res 1992. [DOI: 10.1016/0049-3848(92)90715-m] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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78
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Outcome of [131I]metaiodobenzylguanidine therapy of neuroblastoma: seven years after. JOURNAL OF NUCLEAR BIOLOGY AND MEDICINE (TURIN, ITALY : 1991) 1991; 35:207-15. [PMID: 1823820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Beginning in 1984 and based on a total of 40 treatments with [131I]metaiodobenzylguanidine (131I-MIBG) in most cases with a follow-up of 5 years or more, it seems to be worthwhile reevaluating our clinical data and draw some final conclusions: We treated 12 children with a neuroblastoma (NB) IV and 3 with a NB III. In no case 131I-MIBG was the primary therapy. The great majority suffered from recurrence. The mean treatment interval after chemotherapy was 6 months (range 0-54). We calculated a median cumulative tumor dose of 77 Gy (range 0-259) in patients with stage III and 30 Gy (range 4-267) in stage IV NB. The tumor half-life time of 131I-MIBG does not significantly differ between stage III (3 days) and IV (2-5 days). Although the median tumor dose of stage III NB exceeded that of stage IV, we found in NB IV a significant tumor remission in 7 out of 12 cases. On the other hand, a slight reduction of tumor size was seen in only 1 case of stage III NB. This indicates a lower radiation sensitivity of stage III NB. Despite this fact, the two patients with stage III NB who presented a sufficient 131I-MIBG-tumor uptake turned to become operable after 131I-MIBG. Stage IV patients improved, too, even if most of them suffered from recurrence with a very poor prognosis: 3 patients of stage IV lived longer than 48-60 month or are still alive. However, no one of this group remitted completely.(ABSTRACT TRUNCATED AT 250 WORDS)
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79
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[Thrombolysis with rt-PA in children with arterial and venous thromboses--a new therapy concept]. KLINISCHE PADIATRIE 1991; 203:359-62. [PMID: 1942942 DOI: 10.1055/s-2007-1025453] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Thrombolytic therapy usually used for thrombosis in the adult has been administered as a therapeutic regiment in pediatric patients (parental consent was sought prior to the treatment with rt-PA). We report our experience with rt-PA in 17 children and adolescents suffering from arterial (n = 4) or venous thrombosis (n = 13) due to local rhabdomyosarcoma, acute lymphoblastic leukemia, chronic myeloblastosis, sickle cell anaemia, parenteral nutrition, haemolytic uremic syndrome, central arterial and venous catheters and septicemia Thrombotic diseases have been diagnosed by Doppler ultrasound, computed tomography, angiography and phlebography. Rt-PA therapy was started immediately after diagnostic procedures had been performed. Rt-PA dose varied from 0.2 mg as a single dose to 0.8 mg/kg bw/d over a three day period in children local thrombolysis was performed. In patients requiring systemic thrombolytic therapy rt-PA was administered from 0.8 mg/kg bw/d in three days to 2.0 mg/kg bw/d over a whole period of three weeks in both groups during thrombolysis low dose heparin was added. When rt-PA infusion was terminated heparin (70 IU - 400 IU/kg bw/d) was administered for 7 to 14 days in order to prevent reocclusion. Later prophylaxis with coumarin derivatives in venous thrombosis and antiplatelet agents in arterial occlusive diseases was performed. In no patient did we see a decrease of fibrinogen and plasminogen during rt-PA therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
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80
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The periodic instability of thermocapillary convection in cylindrical liquid bridges. ACTA ACUST UNITED AC 1991. [DOI: 10.1063/1.858135] [Citation(s) in RCA: 168] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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81
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Metaiodobenzylguanidine (mIBG) in treatment of 47 patients with neuroblastoma: results of the German Neuroblastoma Trial. MEDICAL AND PEDIATRIC ONCOLOGY 1991; 19:84-8. [PMID: 2011100 DOI: 10.1002/mpo.2950190203] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
From 1984 to 1989, 47 children with relapsed, refractory, and/or metastasized neuroblastoma were treated with 131I-metaiodobenzylguanidine (mIBG) in several different treatment combinations. At initial diagnosis, 36 children had Evans stage IV and 11 stage III disease. In 16 of the 47 children, tumor recurred after complete remission prior to mIBG treatment, 26 of 47 progressed from residual or nonresponding tumor, and in 5 of 47 tumor progression during chemotherapy was observed. Altogether the children were treated with a total of 112 courses (range 1-6) with a mean dosage of 8.9 +/- 6.7 mCi/kg body weight/treatment course. Total dose was 283.2 +/- 203.7 mCi for stage III and 388.9 +/- 218.6 mCi for stage IV. Nine of 47 children reached a complete or a very good partial remission (CR and VGPR) from mIBG treatment alone, 13 of 47 achieved partial remission (PR). In an early analysis, 10 patients treated with mIBG in the neuroblastoma trial NB 85 of the German Society of Pediatric Oncology showed no significant difference in survival time compared with 30 conventionally treated children. However, the recent therapy series has been done with higher doses of mIBG, and during improved therapeutic scanning many more bone lesions could be detected than during earlier diagnostic scanning. We conclude that mIBG treatment has not yet fulfilled the expectations for it but still seems for certain indications to be a promising tool to treat neuroblastoma in the future. Moreover, the frontier of neuroblastoma detection is still advancing.
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82
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Abstract
A multi-institutional study was undertaken to define the predictive power for mortality of the Rapid Acute Physiology Score (RAPS) in a large and diverse group of transported patients. RAPS is a truncated version of the Acute Physiology and Chronic Health Evaluation (APACHE II) score that uses definitions and weighting consistent with APACHE II, but is modified to provide a consistent score just before transport, just after transport, and to use the most deranged (worst) physiologic values during the initial 4 h after arrival at the receiving hospital. During an 8-month period, 1,927 patients transported by six helicopter emergency medical service programs were studied. Over 97% (1,881) of the patients had RAPS obtained before and after transport to the receiving hospital and 92.6% (1,785) had APACHE II scoring completed after hospital admission. Receiver operating curves demonstrate similar predictive power for RAPS and APACHE II (both based on the most deranged physiologic values during the initial 24 h after admission). Before- and after-transport RAPS were also highly predictive of mortality. RAPS appears to be a reliable and highly predictive measure of patient severity/physiologic stability before and after transport to critical care.
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83
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Abstract
The purpose of this study was to measure the predictive power of Acute Physiology and Chronic Health Evaluation (APACHE II) with respect to mortality in a group of seriously injured patients and to compare this predictive power with that of the Trauma Score (TS) and the Injury Severity Score (ISS). Six hundred ninety-one helicopter-transported patients were studied. Individual logistic regressions demonstrated that all three scores had significant predictive power when considered individually (TS chi 2 = 136, p less than .0001; APACHE II chi 2 = 171, p less than .0001; ISS chi 2 = 109, p less than .0001). In addition, each severity score added significantly to the predictive power in a stepwise logistic regression (TS chi 2 = 15, p less than .0001; APACHE II chi 2 = 45, p less than .0001; ISS chi 2 = 15, p less than .0001). Areas under the receiver operating curves for the three scores were not significantly different (TS 0.8116, SD 0.0245; APACHE II 0.8515, SD 0.0204; ISS 0.7967; SD 0.0223). APACHE II is a good predictor of mortality, and its predictive power is complemented by TS and ISS.
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84
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Abstract
Severity of illness or injury should be the primary justification for aeromedical transport. To determine whether differences in patient severity were detectable in air transport programs, helicopter-transported patients were examined by three established physiologic scores: the Trauma Score, the Acute Physiology and Chronic Health Evaluation Score, and the Rapid Acute Physiology Score. These scores were obtained prospectively on 1,868 consecutive patient transfer requests from six air medical services for periods ranging from two to six months. A patient meeting strict physiologic criteria was considered critically ill. Overall, 42.6% of the patients (range, 34.8% to 53.3%) were considered critically ill. Patients transported from inpatient hospital units and patients with cardiac disease were less likely to be critically ill than those transported emergently from scenes of accident or from emergency departments. There were also significant differences between programs with regard to the percentage of critically ill patients transported. This study suggests that physiologic scoring may be useful in comparing air ambulance programs and that a majority of patients transported by these services may not be critically ill.
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85
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[Prevention of cytomegalic inclusion disease in leukemia patients with a cytomegalovirus hyperimmune globulin preparation]. KLINISCHE PADIATRIE 1989; 201:322-9. [PMID: 2550700 DOI: 10.1055/s-2008-1026722] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In a randomised study the efficacy of a cytomegalic hyperimmune globulin preparation (CMV-HIGP) which had been treated with beta-propiolactone was analysed. The study included 85 patients with acute lymphoblastic leukemia (ALL) and Non-B-Non-Hodgkin-lymphoma (NHL) who were treated initially or underwent a relapse therapy. During the intense chemotherapeutical period within leukemia treatment the patients were passively immunised by the intravenous route with CMV-HIGP (1 ml per kilogram of body weight) every two to three weeks at the latest. In the initial stages the basic immunisation protection was achieved by the application of double dose CMV-HIGP. The Frankfurt patients were recruited from the BFM-ALL- and the NHL-study since october 1982. When they were admitted their CMV serostatus was determined by means of the ELA-ELISA or IFA-method. Seronegative patients were given the passive immunisation immediately or 48 hours after the first blood transfusions at the latest. The patients who had become CMV-IgG-positive by passive immunisation were randomised when reaching long-term therapy according to the protocol. Because of a 30% cytomegaly disease incidence rate in our patient population a randomisation was unwarrantable at the beginning of leukemia treatment. During randomisation one group of patients were immunised by the intravenous route with CMV-HIGP (2 ml per kg body weight one time in four weeks), the second group was a control group.(ABSTRACT TRUNCATED AT 250 WORDS)
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86
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Determination of m-iodobenzylguanidine in serum and urine by high-performance liquid chromatography. JOURNAL OF CHROMATOGRAPHY 1989; 487:177-82. [PMID: 2715263 DOI: 10.1016/s0378-4347(00)83022-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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87
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Abstract
Chromosome analysis of tumour cells in the bone marrow of a 13.5-year-old girl (without a primary tumour) revealed a pseudo-diploid or pseudo-tetraploid karyotype with a translocation involving the long arms of chromosomes 2 and 13: t(2;13)(q37;q14). This finding enabled the diagnosis of a disseminated alveolar rhabdomyosarcoma (RMS) to be established. The patient was treated by cytotoxic chemotherapy, went into complete remission, but died of relapse 14 months after diagnosis. As several cases with this translocation have been described recently, this additional report confirms that t(2;13) is specific for the alveolar subtype of RMS.
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88
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Late abstracts 186–187. Clin Exp Metastasis 1988. [DOI: 10.1007/bf01888832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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89
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Abstract
Eleven children with neuroblastoma refractory to conventional therapy or relapse of neuroblastoma were treated with 131-metaiodobenzylguanedine (MIBG). The therapeutic results and the side effects were evaluated. In one patient with disseminated bone marrow involvement complete remission was obtained. Partial remission was observed in six patients and stable disease in another. Three patients did not respond to MIBG, in two of them the tumours did not accumulate a sufficient MIBG dose. Clinical and laboratory examinations revealed an excellent tolerance of MIBG in all patients. First attempts to continue cytostasis after MIBG therapy were made. MIBG has a good therapeutic efficacy is sufficiently incorporated into the tumour cell.
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90
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[Initial experiences in the treatment of children with metastatic and recurrent neuroblastoma using meta-iodobenzylguanidine]. KLINISCHE PADIATRIE 1986; 198:230-6. [PMID: 3723987 DOI: 10.1055/s-2008-1026882] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
At four involved hospitals 16 children were treated with Metaiodobenzylguanidine (131J-MIBG). These children had a relapse of neuroblastoma stage III or IV or did not respond sufficiently to chemotherapy. In 10 children extreme bone pain disappeared and they became free of fever during the MIBG-treatment. 10 children responded to the therapy demonstrated either by decrease of the solid tumor part or by decrease of catecholamines in urine or plasma or by decrease of bone-marrow involvement. One patient reached a complete remission continuing up to present time (longer than 180 days). 9 patients died meanwhile of tumor progression. 131J-MIBG is an effective instrument, to get a decrease of the tumor up to a complete remission in extensively pretreated patients with tumor relapse, which are refractory to chemotherapy.
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91
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EXPERIMENTS ON THERMOCAPILLARY CONVECTION WITH APPLICATION TO CRYSTAL GROWTH FROM THE MELT. Ann N Y Acad Sci 1983. [DOI: 10.1111/j.1749-6632.1983.tb19532.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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92
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Immunochemical aspects, molecular and kinetic properties of multiple forms of acetyl-CoA acetyltransferase from rat liver mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 575:112-20. [PMID: 41585 DOI: 10.1016/0005-2760(79)90136-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Acetyl-CoA acetyltransferase (EC 2.3.1.9) from rat liver mitochondria, which catalyzes the first step in the biosynthesis of ketone bodies, exists in two forms, designated transferase A and transferase B. Both transferases showed immunochemical cross-reactivity, but are immunologically unrelated to cytosolic acetyl-CoA acetyltransferase activity and the mitochondrial acetyl-CoA acyltransferase from rat liver. The transferases A and B were estimated to have molecular weights of 151 000 in the absence and 40 000 in the presence of sodium dodecyl sulfate. They differ with respect to charge states and multiplicity of forms as indicated by isoelectric focusing. Transferase A appeared in two forms with isoelectric points of 8.4 and 9.1, whereas transferase B represents a stable protein state with an isoelectric point of 9.0. Kinetic analysis of the reactions leading to acetoacetyl-CoA synthesis revealed saturation curves with multiple intermediary plateaus, indicating a complex kinetic behaviour. The data presented are interpreted as representing a microheterogeneity of forms of the mitochondrial acetyl-CoA acetyltransferase. The kinetic properties exhibited suggest a role for this microheterogeneity in the regulation of ketogenesis.
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