Interference Of High-Dose Methotrexate In The Metabolism Of Valproate?

A case of tonic-clonic seizure was obserued in a child with acute lymphoblastic leukemia a few hours after a 24-hour infusion of high-dose methotrexate (MTX; 5 g/m²). Because of former epileptic symptoms, the child had been treated with valproic acid for several months. During this and the following high-dose MTX infusion, an acute decline of the serum valproate concentration to about 25% of the pre-MTX value was observed. The pathogenesis of the acute decline of serum valproate concentration is discussed.     

Neonatology in developed and developing nations

Neonatal care has made tremendous improvements in developing countries. However there are number of challenges to be met and neonatal mortality remains unacceptably high. In contrast to this neonatal care in developed nations have moved ahead of a pre-occupation to reducing the neonatal mortality only. The main reasons for this gap are poor infrastructure, resource limitations and lack of systems developed by neonatal units in the developed nations. Though this communication we explore the possibilities of application of health policies in the Australian neonatal units n developing countries.     

Cmogenetic Analysis In The Examination Of Solid Tumors In Children

Although pediatric solid tumors are cytogenetically less well characterized than childhood leukemias, an understanding of the role of chromosomal changes in the development of these neoplasms is emerging. The major clinical importance of chromosome analysis today is diagnostic. Especially in small cell round cell tumors of childhood, the unique karyotypic patterns that characterize some of the differential diagnostic entities make it possible to determine with a high degree of certainty which type of cancer the child has. Molecular studies have revealed that almost all retinoblastomas show homozygous loss of function of the RBI gene in 13q14. At the cytogenetic level, however, aberrations of 13q are seen in less than 25% of retinoblastomas; instead, the presumably progression-related i(6p) and aberrations leading to gain of 1q predominate, each being present in one-third of the tumors. Twenb percent of cytogenetically aberrant Wilms' tumors show structural rearrangements, often deletions, of 11p13 and 11 p15, where the WT1 and WT2 genes map. Other frequent changes are trisomy 12 and duplication of 1q. The most common (80%) cytogenetic abnormality in neuroblastoma is loss of distal 1p, a chromosome segment thought to harbor at least two tumor-suppressor genes of importance in tumorigenesis. Double minute chromosomes or homogeneously staining regions are present in one-third of all neuroblastomas and are associated with MYCN amplification. Loss of 1p material or MYCN amplification predicts a poor outcome. The most common (30%) chromosomal aberration in primitive neuroectodermal tumors of the central nervous system is i(17q). The formation of this isochromosome may help inactivate a tumor-suppressor gene located distal to the TP53 locus on 17p. No specific chromosome abnormality has been detected in gliomas, but monosomy 22 and rearrangements leading to loss of 1p and gain of 1q are recurrent. Few hepatoblastomas with chromosomal changes have been reported, but several potential primary aberrations have been described, including + 2, + 20, and duplication 8q. In Ewing's sarcoma, t(l1;22)(q24;q12) is the primary aberration, with trisomy 8 and gain of 1q being frequent secondary changes. Fibrosarcomas in children often carry only numeric aberrations, especially trisomy for chromosomes 11, 20, 17, and 8. Most osteosarcomas are cytogenetically complex, and no specific abnormality has been detected; the single most common change is loss of chromosome 13, which is observed in half the tumors. In contrast, the low-malignancy parosteal osteosarcomas often display supernumerary ring chromosomes as the sole karyotypic deviation. The cytogenetic profiles of rhabdomyosarcomas differ among the various morphologic subtypes. The alveolar type is characterized by t(2;13)(q35-37;q14), whereas the embryonal form typically has only numeric changes, in. particular +2, + 8, + 11, and +20.     

Neonatology in the 'Pearl of the East'

ABSTRACT Clinicians practising in different regions of the world are often impressed at marked differences in disease patterns witnessed. The bases of most obvious differences are usually socio-economic and genetic, but culture and environment can be equally important. Documenting and assessing such differences is more than just a passing interest. Globalization has resulted in significant movement of people from one area to another. During the past decade, many young Chinese families have emmigratad to Australia, Europe and North America for social and political reasons. Clinicians in these regions will need to be aware of the 'Chinese disease patterns'. The overview highlights some of the more striking differences seen in neonatal medicine between the East (Hong Kong) and the West (Australia/Europe/North America). In addition to the immediate clinical relevance, it is hoped that this review can provide a background from which fruitful research ideas may emerge and to stimulate interest for trainee neonatologists who wish to seek sabbatical experience in Hong Kong.