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Biomedical subjects

D Schuler

Publications and source records attributed to D Schuler.

At least 19 recordsLinked to original sources

Treatment of malignant scala posterior brain tumors in children: the chemotherapy of relapsed medulloblastoma with a dibromdulcitol containing drug regime and pharmacokinetic studies of dibromdulcitol in children.

Dibromdulcitol (Elobromol) has favorable pharmacokinetic parameters for the treatment of brain tumors: high spinal fluid/plasma ratio and long half-life in spinal fluid. Oral application makes its administration easy. The drug combination vincristine, procarbazine, and dibromdulcitol proved to be effective in a pilot trial on relapsed medulloblastomas: 8 complete and 4 partial remissions were achieved from 16 cases. The main side effect was granulocytopenia, which was in some cases severe. However, in the dose-schedule we used it did not delay the treatment longer than 1 week.

Adolescent

Paediatric care in Hungary.

In this overview, I have attempted to highlight the problems of medical care, particularly paediatric care, in Hungary and to describe the changing nature of its organisation and financing. We hope that through our efforts we can surmount these difficulties, improve the quality of medical care in our country, and create a more rational economic and scientific basis for future medical development and advances.

Child

Immunoglobulin prophylaxis during intensive treatment of acute lymphoblastic leukemia in children.

60 children with acute lymphoblastic leukemia were sequentially randomized at the time of diagnosis: Immunoglobulin (Endobulin, Immuno) was administered intravenously to 30 patients at a dose 100 mg/kg/week during the first 3 months, followed by 2 x 200 mg/kg/month immunoglobulin during the 4., 5., 6. months. No immunoglobulin was administered to the control patients. We studied the effect of immunoglobulin prophylaxis on the number of days with fever, number of cases with bacteriologically proved infections, length and frequency of antibiotic therapy. Our data confirm the efficacy of immunoglobulin prophylaxis during the intensive phase of leukemia therapy in children.

Child

Value of brainstem acoustic evoked potentials in posterior fossa tumours in childhood.

Brainstem acoustic evoked potentials (BAEPs) were measured in 14 children with different type of posterior fossa tumours several times during the clinical course, in order to assess the value of this simple and non-invasive method in the diagnosis and follow-up of posterior fossa tumours in childhood. Eight children had midline medulloblastoma, three children had lateral astrocytoma, three had intrinsic brainstem glioma. Different BAEP patterns could be detected in different tumour's type: bilateral symmetrical or slightly asymmetrical I-V. IPL prolongation in midline medulloblastomas, unilateral or markedly asymmetrical I.-V. IPL prolongation or wave V. depression on the contralateral side in lateral astrocytomas, and severely distorted asymmetrical waveform in intrinsic brainstem gliomas. The BAEPs were abnormal earlier than CT scan in a case of craniospinal astrocytoma. BAEPs were useful in the follow-up: the effect of the preoperative chemotherapy or the progression of the inoperable tumours could be as well documented by this method, as by the CT scan. BAEPs proved effective in the assessment of postoperative neurological complications: bilateral symmetrical IPL prolongation and wave V. depression with clinical signs of increased intracranial pressure occurred in a case of postoperative occlusive hydrocephalus, unilateral IPL prolongation occurred during irradiation or chemotherapy after medulloblastoma removal as signs of cerebral oedema.

Adolescent

Neuropsychologic and CT examinations in leukemic patients surviving 10 or more years.

Long-term survivors of childhood leukemia were studied to determine their neuropsychologic status. All had had cranial irradiation 10 or more years before. The results were 1. The IQ and academic performance of 56 cured leukemic patients show no significant difference from the normal population. 2. More exact neuropsychological tests (attention, reaction time, visual-motor coordination, memory) reveal important deficits. 3. The frequency of CT aberrations in 33 study patients was 45% and showed no correlation with either the IQ or other neuropsychological results.

Adolescent

Molecular genetics of PKU in eastern Europe: a nonsense mutation associated with haplotype 4 of the phenylalanine hydroxylase gene.

Phenylketonuria (PKU) is a genetic disorder secondary to a deficiency of hepatic phenylalanine hydroxylase (PAH). Several mutations in the PAH gene have recently been reported, and linkage disequilibrium was observed between RFLP haplotypes and specific mutations. A new molecular lesion has been identified in exon 7 of the PAH gene in a Hungarian PKU patient by direct sequencing of PCR-amplified DNA. The C-to-T transition causes the substitution of Arg243 to a termination codon, and the mutant allele is associated with haplotype 4 of the PAH gene. The mutation is present in two of nine mutant haplotype 4 alleles among Eastern Europeans and is not present among Western Europeans and Asians. The rarity of this mutant allele and its restricted geographic distribution suggest that the mutational event occurred recently on a normal haplotype 4 background in Eastern Europe.

Alleles

[The significance of the determination of catecholamines and their metabolites in neuroblastomas].

A method for the determination of catecholamines and their metabolites in the urine was established. The specimens were previously cleaned by ion exchangers and the components were separated by a 'reversed phase' ionic pair chromatography, determined by an electrochemical 'wall-jet'-detector. This method was applied in order to find a diagnostic marker in case of neuroblastoma diseases. In 85 per cent of the patients (n = 13) we stated an increased ejection of dopamine.

Biomarkers, Tumor

[Neurologic tests in children having recovered from leukemia].

56 long-term survivors of childhood ALL have been investigated with CT and neuro-psychological methods. At the CT examination we found that 45.4% of the cured patients had alterations. Short-term memory, attention, visual-motor coordination and IQ were found to be slightly impaired in this group. Nevertheless they didn't influence the social integration and educational achievement of long-term survivors of ALL.

Adolescent

Polymorphic DNA haplotypes at the phenylalanine hydroxylase (PAH) locus in European families with phenylketonuria (PKU).

DNA haplotype data from the phenylalanine hydroxylase (PAH) locus are available from a number of European populations as a result of RFLP testing for genetic counseling in families with phenylketonuria (PKU). We have analyzed data from Hungary and Czechoslovakia together with published data from five additional countries--Denmark, Switzerland, Scotland, Germany, and France--representing a broad geographic and ethnographic range. The data include 686 complete chromosomal haplotypes for eight RFLP sites assayed in 202 unrelated Caucasian families with PKU. Forty-six distinct RFLP haplotypes have been observed to date, 10 unique to PKU-bearing chromosomes, 12 unique to non-PKU chromosomes, and the remainder found in association with both types. Despite the large number of haplotypes observed (still much less than the theoretical maximum of 384), five haplotypes alone account for more than 76% of normal European chromosomes and four haplotypes alone account for more than 80% of PKU-bearing chromosomes. We evaluated the distribution of haplotypes and alleles within these populations and calculated pairwise disequilibrium values between RFLP sites and between these sites and a hypothetical PKU "locus." These are statistically significant differences between European populations in the frequencies of non-PKU chromosomal haplotypes (P = .025) and PKU chromosomal haplotypes (P much less than .001). Haplotype frequencies of the PKU and non-PKU chromosomes also differ significantly (P much less than .001. Disequilibrium values are consistent with the PAH physical map and support the molecular evidence for multiple, independent PKU mutations in Caucasians. However, the data do not support a single geographic origin for these mutations.(ABSTRACT TRUNCATED AT 250 WORDS)

Alleles

Methotrexate administered by 6-h and 24-h infusion: a pharmacokinetic comparison.

The pharmacokinetics of 8 g/m2 methotrexate (MTX) was compared following short (6 h) and long (24 h) infusions of the drug to 11 children with osteogenic sarcoma (OS; 42 infusion) and 28 children with acute lymphoblastic leukemia (ALL: 118 infusions), respectively. No difference was observed in the first-phase half-life, in systemic clearance or in the volume of distribution of the drug (P greater than 0.05). The concentration of MTX at the end of the infusion was approximately 4-fold higher when the drug was given over only 6 h. However, patients receiving 24-h infusions had approximately 9-fold higher levels by 24 h after the beginning of the infusion. The area under the data curve from start of the MTX infusion until the beginning of folinic acid rescue administration was significantly higher in patients with osteogenic sarcoma (6-h infusions), while the area under the log-data curve was significantly longer in the ALL group (24-h infusions) for the same period. The latter parameter is considered to be characteristic for the concentration-time-effect relationship. The longer duration of MTX administration (with delayed rescue) is thought to be more beneficial from the pharmacokinetic aspect. Patients with osteogenic sarcoma had significantly lower concentrations of MTX at the end of their last treatment with MTX than at the end of the first infusion. Patients developing MTX toxicity had shorter half-lives of MTX in the beta phase. It is suggested that cisplatin induced tubular loss of MTX and folinic acid is responsible for these observations. A wider application of clinical pharmacologic findings in the practice of the administration of cytostatics is indicated.

Child

Cytogenetic investigations on children with acute non-lymphocytic leukemia.

Cytogenetic data from 30 children with acute non-lymphocytic leukemia (ANLL) are evaluated in connection with patient's age, morphological type of leukemia and prognosis. In 20 out of 30 patients clonal chromosome aberrations were found. The frequency of chromosome aberrations and the prognostic parameters in the various morphological and age groups proved to be different and no direct relationship could be found in a given group between the frequency of aberrations and the prognosis. A more detailed analysis of data, however, provided some evidence that chromosome aberrations observed at diagnosis had a prognostic value independent of age and the morphological properties of blast cells: the normal karyotype and the pseudodiploidy proved to be of a favorable value but the hyperdiploidy and polyploidy an unfavorable prognostic parameter. Besides the known cytogenetic differences between childhood and adult ANLL, some similarities are also emphasized.

Acute Disease