Initial management of childhood brain tumors: neurosurgical considerations

Intracranial tumors are the most common solid tumors in children. The infratentorial compartment will be the primary site for 60% to 70% of these tumors, including astrocytomas, medulloblastomas, and ependymomas. Several technological advancements have increased our knowledge of the cell biology of pediatric brain tumors, facilitated earlier diagnosis, and improved neurosurgical resections while minimizing neurological deficits. These in turn have not only improved the survival of children with brain tumors but also their quality of life. Current management strategies in most cases rely on surgery coupled with adjuvant therapies, including radiation therapy and chemotherapy. The vulnerability of the immature brain to adjuvant therapies creates many challenges for the treating physician. We review current diagnostic and therapeutic approaches and outcome for children harboring the most common pediatric brain tumors: astrocytomas (low-grade and high-grade glioma), ependymoma, medulloblastoma, and craniopharyngioma. The emphasis will be on the neurosurgical management of children with these tumors.     

Association of HLA class II allele and haplotype frequencies with chronic myelogenous leukemia and age-at-onset of the disease

Chronic myelogenous leukemia (CML) is characterized by the presence of Philadelphia chromosome resulting from bcr/abl translocation. To clarify the association between HLA class II allele and haplotype frequencies in CML, 50 patients referred to Hematology Oncology and Bone Marrow Transplantation (BMT) center, Shariaty Hospital, Tehran, Iran, were randomly selected and compared with a group of 80 unrelated healthy blood donor subjects. HLA class II alleles were determined by PCR-SSP method. The results showed that the frequencies of DQB1*03011 (P=0.01) and DQA1*0505 (P=0.05) were higher, while that of DQB1*03032 (P=0.04) was lower in patients than in the controls. Regarding age-at-onset, the frequency of HLA-DRB1*07 (P=0.03) and -DQA1*0201 (P=0.03) alleles were higher in patients younger than 35 years. The most frequent haplotypes in our CML patients were HLA-DRB1*11/-DQB1*03011/-DQA1*0505 (P=0.01) and HLA-DRB1*04/-DQB1*0302/-DQA1*03011 (P=0.02). In conclusion, it is suggested that positive and negative association in certain HLA alleles and haplotypes exist in Iranian patients with CML.     

Investigation of HSV-1, HSV-2, CMV, HHV-6 and HHV-8 DNA by real-time PCR in surgical resection materials of epilepsy patients with mesial temporal lobe sclerosis

OBJECTIVE: The objective of this study is to investigate the presence of viral DNAs of HSV-1, HSV-2, HHV-6, HHV-8, and CMV in hippocampus of the patients with mesial temporal lobe epilepsy (MTLE) syndrome. METHODS: Pathological specimens were obtained from 33 patients with MTLE undergone temporal lobectomy with amygdalo-hippocampectomy due to intractable seizures. Autopsy materials from the hippocampus of 7 patients without neurological disease were used as controls. The data was also correlated with the clinical history of patients including febrile convulsions, age, and history of CNS infections. Real-time polymerase chain reaction method was performed for detection of DNAs of these viruses. RESULTS: HHV-6, HSV-1 and HHV-8 were detected in the hippocampus of 3, 2 and 1 patients with MTLE respectively. None of the hippocampus of patients with MTLE was positive for DNA of HSV-2 and/or CMV. Three patients with positive HHV-6 DNAs had febrile convulsions and family history for epilepsy. None of our control specimens showed PCR positivity to any of the 5 tested viruses. CONCLUSIONS: Our study is the first to report the presence of HHV-8 viral genome in the brain tissue of patient with MTLE. Viral DNAs were detected in a total of 18% of the patients in this study; we can conclude that activity of the latent virus in patients with hippocampal sclerosis should be more extensively studied to establish its role in active infection.     

Frequency of paraoxonase 192/55 polymorphism in an Iranian population

Paraoxonase (PON1) is a serum enzyme that plays an important role in prevention of atherosclerosis and also protects against organophosphate-induced neurotoxicity. PON1 displays a high variability in human populations. In this study, PON1-192 and -55 polymorphisms and correlation to serum PON1 activity were investigated in 132 healthy Iranian individuals from Isfahan province. The genotype frequencies for PON1-192 were approximately 48% (QQ), 42.% (QR), and 10% (RR) and for PON1-55 17% (MM), 48% (ML), and 35% (LL). Thus, the frequencies of alleles R and L were 0.31 and 0.59, respectively. PON1 activity toward paraoxon was markedly affected in both polymorphic populations in the following order QQ < QR < RR genotype for PON1-192 and MM < ML < LL genotype for PON1-55. Neither polymorphism significantly affected PON1 activity toward phenylacetate. The RR/LL individuals had the highest PON1 activity and QQ/MM individuals the least. The QR/ML haplotype was the most frequent seen in Iranians, and the RR/MM and QR/MM haplotypes were absent in this population. In conclusion, the frequencies of PON1-192 and -55 polymorphisms in this Iranian population were different from those seen in other Asian populations from Japan and China but similar to those for European Caucasians.     

Impact of Global Economic Disparities on Practices and Outcomes of Chronic Peritoneal Dialysis in Children: Insights from the International Pediatric Peritoneal Dialysis Network Registry

Background, Objectives, and METHODS: The number of patients on chronic peritoneal dialysis (CPD) is increasing rapidly on a global scale. We analyzed the International Pediatric Peritoneal Dialysis Network (IPPN) registry, a global database active in 33 countries spanning a wide range in gross national income (GNI), to identify the impact of economic conditions on CPD practices and outcomes in children and adolescents. ? RESULTS: We observed close associations of GNI with the fraction of very young patients on dialysis, the presence and number of comorbidities, the prevalence of patients with unexplained causes of end-stage kidney disease, and the rate of culture-negative peritonitis. The prevalence of automated PD increased with GNI, but was 46% even in the lowest GNI stratum. The GNI stratum also affected the use of biocompatible peritoneal dialysis fluids, enteral tube feeding, calcium-free phosphate binders, active vitamin D analogs, and erythropoiesis-stimulating agents (ESAs). Patient mortality was strongly affected by GNI (hazard ratio per $10 000: 3.3; 95% confidence interval: 2.0 to 5.5) independently of young patient age and the number of comorbidities present. Patients from low-income countries tended to die more often from infections unrelated to CPD (5 of 9 vs 15 of 61, p = 0.1). The GNI was also a strong independent predictor of standardized height (p < 0.0001), adding to the impact of congenital renal disease, anuria, age at PD start, and dialysis vintage. Patients from the lower economic strata (GNI < $18 000) had higher serum parathyroid hormone (PTH) and lower serum calcium, and achieved lower hemoglobin concentrations. No impact of GNI was observed with regard to CPD technique survival or peritonitis incidence. ? CONCLUSIONS: We conclude that CPD is practiced successfully, albeit with major regional variation related to economic differences, in children around the globe. The variations encompass the acceptance of very young patients and those with associated comorbidities to chronic dialysis programs, the use of automated PD and expensive drugs, and the diagnostic management of peritonitis. These variations in practice related to economic difference do not appear to affect PD technique survival; however, economic conditions seem to affect mortality on dialysis and standardized height, a marker of global child morbidity.     

Autosomal Recessive Nonsyndromic Arrhythmogenic Right Ventricular Cardiomyopathy without Cutaneous Involvements: A Novel Mutation

The arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is a genetic disease frequently associated with desmosomal mutations, mainly attributed to dominant mutations in the Plakophilin‐2 (PKP2) gene. Naxos and Carvajal are the syndromic forms of ARVD/C due to recessive mutations. Herein, we report an autosomal recessive form of nonsyndromic ARVD/C caused by a mutation in the PKP2 gene. After examination and implementation of diagnostic modalities, the definite diagnosis of ARVD/C was confirmed by detection of ventricular tachycardia with a left bundle branch configuration and a superior axis, T‐wave inversion in right precordial leads (i.e., V1‐V3) in a 12‐lead electrocardiogram, and a right ventricle outflow tract dilatation. Neither cutaneous involvement nor other abnormalities were observed. Genetic testing was performed during which an intronic mutation of c.2577+1G>T in the PKP2 gene was observed homozygously. The c.2577+1G>T disrupts PKP2 mRNA splicing and causes a nonsyndromic form of ARVD/C.     

Human leukocyte antigen profile in the Zaboli ethnic group living in the South-East region of Iran

The human leukocyte antigen has become a key component in investigating the genetic relationships between populations. The aim of this study was to determine the genetic diversity of HLA class I and II alleles among Zaboli ethnic group of South-east Iran to establish a database for further investigations on ancestry and the genetic factors contributing to complex diseases in this region.Unrelated individuals from the Southeast geographic location throughout Iran were serologically typed using standard microcytotoxicity assays with commercial and local trays. The ethnic background of each individual was self-defined. HLA profiles were determined in 41 Zaboli populations. The most frequent class I alleles of the Zaboli ethnic group being the following: HLA-A1 (34.1%), -A2 (58.5%), -A11 (29.3%), -A24 (23.9%), -B5 (70.7%), -B16 (26.8%), and -Cw4 (24.4%). The class II alleles more frequently observed in this group were HLA-DR1 (26.8%), -DR2 (26.8%), -DR3 (31.7%), -DR4 (29.3%), -DR7 (24.4%), -DR8 (22%), -DR11 (48.8%), -DRw52 (73.2%), -DRw53 (53.7%), -DQ1 (53.7%), -DQ2 (31.7%), and -DQ3 (29.3%). This report utilized a first study of HLA class I and II typed individuals, from widely dispersed areas of Iran. This will help in studies related to disease associations and cadaver organ allocation programmes.