Kanamycin treatment in the pre-symptomatic stage of a Drosophila PD model prevents the onset of non-motor alterations.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor alterations, which is preceded by a prodromal stage where non-motor symptoms are observed. Over recent years, it has become evident that this disorder involves other organs that communicate with the brain like the gut. Importantly, the microbial community that lives in the gut plays a key role in this communication, the so-called microbiota-gut-brain axis. Alterations in this axis have been associated to several disorders including PD. Here we proposed that the gut microbiota is different in the presymptomatic stage of a Drosophila model for PD, the Pink1B9 mutant fly, as compared to that observed in control animals. Our results show this is the case: there is basal dysbiosis in mutant animals evidenced by substantial difference in the composition of midgut microbiota in 8-9 days old Pink1B9 mutant flies as compared with control animals. Further, we fed young adult control and mutant flies kanamycin and analyzed motor and non-motor behavioral parameters in these animals. Data show that kanamycin treatment induces the recovery of some of the non-motor parameters altered in the pre-motor stage of the PD fly model, while there is no substantial change in locomotor parameters recorded at this stage. On the other hand, our results show that feeding young animals the antibiotic, results in a long-lasting improvement of locomotion in control flies. Our data support that manipulations of gut microbiota in young animals could have beneficial effects on PD progression and age-dependent motor impairments. This article is part of the Special Issue on "Microbiome & the Brain: Mechanisms & Maladies".

Detection of sentinel bacteria in mangrove sediments contaminated with heavy metals.

Mangroves in the Northwest Coast of South America are contaminated with heavy metals due to wastewater discharges from industries, affecting the biota from this environment. However, bacteria proliferate in these harsh environmental conditions becoming possible sentinel of these contaminations. In this study, bacterial community composition was analyzed by throughput sequencing of the 16S rRNA gene from polluted and pristine mangrove sediments affected by marked differences in heavy metal concentrations. Core bacteria were dominated by Proteobacteria, Firmicutes, and Bacteroidetes phyla, with strong differences between sites at class and genus levels, correlated with metal levels. Increment of abundance on specific OTUs were associated with either elevated or decreased concentrations of metals and with the sulfur cycle. The abundance of Sulfurovum lithotrophicum, Leptolinea tardivitalis, Desulfococcus multivorans and Aminobacterium colombiense increases when metals rise. On contrary, Bacillus stamsii, Nioella nitrareducens and Clostridiisalibacter paucivorans abundance increases when metal levels are reduced. We propose these OTUs as bacterial sentinels, whose abundance can help monitor the restoration programs of contaminated mangrove sediments in the future.

Successful treatment of metastatic retinoblastoma with high-dose chemotherapy and autologous stem cell rescue in South America.

High-dose chemotherapy (HDC) followed by autologous stem cell rescue (ASCR) is the only curative treatment for metastatic retinoblastoma, but its feasibility in developing countries is unknown. We report 11 consecutive children (six unilateral) treated in three South-American middle-income countries with HDC-ASCR. One patient had metastatic retinoblastoma at diagnosis and the remaining ones had a metastatic relapse. Metastatic sites included BM=6, bone=4, orbit=5 and central nervous system (CNS)=4. All patients received induction with conventional chemotherapy achieving CR at a median of 5.7 months from the diagnosis of metastasis. Conditioning regimens included carboplatin and etoposide with thiotepa in six or with CY in four or melphalan in one patient. All patients engrafted after G-CSF-mobilized peripheral blood ASCR and no toxic deaths occurred. Two children received post-ASCR CNS radiotherapy. Seven children have disease-free survival (median follow-up 39 months). CNS relapse, isolated (n=3) or with systemic relapse (n=1), occurring at a median of 7 months after ASCT was the most common event. In the same period, five children with metastatic retinoblastoma did not qualify for HDC-ASCR and died. We conclude that HDC-ASCR is a feasible and effective treatment for children with metastatic retinoblastoma in middle-income countries.

Ros production by endogenously generated Protoporphyrin IX in murine leukemia cells.

Endogenous production of Protoporphyrin IX (PpIX) is successfully exploited for photodynamic therapy (PDT) on malignant cells, following 5-aminolevulinic acid (ALA) administration and light irradiation. This treatment kills cancer cells by damaging organelles and impairing metabolic pathways via cellular reactive oxygen species (ROS) generation. We studied the efficiency of PpIX synthetized from ALA on ROS generation, in the Vincristine resistant (LBR-V160), Doxorubicin resistant (LBR-D160) and sensitive (LBR-) murine leukemia cell lines. Cells were incubated 4 hr with 1 mM ALA and then irradiated during different times with fluorescent light. One hour later, production of ROS was analyzed by flow cytometry using different fluorescent probes: Hydroethidine (HE) for superoxide anion, 2',7' Dichlorodihydrofluorescein diacetate (DCFH-DA) for hydrogen peroxide; mitochondrial damage was examined with 3,3' Dihexyloxacarbocyanine iodide (DiOC6). We found that superoxide anion production in the three cell lines increased with irradiation time whereas no peroxide hydrogen was detected. Mitochondrial damage also increased in an irradiation time dependent manner, being higher in the Vincristine resistant line. Previous studies have demonstrated that apoptotic cell death increased with irradiation time, which is consistent with these results, indicating that ROS are critical in ALA-PDT efficiency to kill malignant cells.

Registro oncopediátrico hospitalario argentino / The argentina ocopediatric hospital registry

El registro Oncopediátrico Hospitalario Argentino (ROHA). Fundación Laleidos registra pacientes menores de 15 años con nuevo diagnóstico de cáncer desde el año 2000. El primer objetivo fue desarrollar un registro de cáncer infantil siguiendo los lineamientos internacionales (OMS/IARC) conun modelo único. El segundo objetivo fue la coordinación y centralización de la información para análisis estadístico de los datos a nivel local, provincial, regional y nacional. Población y Metodo: Las fuentes de ROHA son las instituciones públicas y privadas que atienden niños con patología oncológíca, registros regionales de cáncer, grupos coopertivos de trabajo, datos de defunciones aportados por la Dirección de Estadísticas e Información de Salud del MInisterio de Salud de la Nación y profesionales que atienden niños con cancer en forma particular. Actualmente ROHA cuenta con 67 fuentes registrantes, 8 registros de Tumores Poblacionales y 2 grupos médicos cooperativos quienes son responsables de la notificación de los casos y del seguimiento activo. Resltados: La estimaición de la cobertura actual de ROHA de los casos registrados en relación con los casos esperados para todo el país es de 92. En el período 2000-2005 se registraron 7583 niños con patología oncológica, promedio anual 1264, el 56 es de sexo masculino, las leucemias representan el 36,7, le siguen en orden de frecuencia los tumores cerebrales con el 18,9. El 86 de los pacientes registrados, se atienden eninstituciones públicas y el 37 deben migrar para realizar parte de su tratamiento. Conclusiones: ROHA alcanzó una cobertura nacional estimada de aproximadamente 92. Existe una concordancia de los resultados generales de RPHA con las publicaciones internacionales. Se observó una desigualdad de oportunidades diagnósticas de sostén y terapéuticas, dependiendo de las instituciones en las diferentes áreas geográficas del país.

Bone metastases from secondary glioblastoma multiforme: a case report.

Extraneural metastases of glioblastoma multiforme (GBM) are a relatively rare occurrence which usually manifest after de novo GBM. We report a case of a patient with an oligodendroastrocytoma who developed over a period of 12 years malignant progression to glioblastoma followed by multiple cytologically confirmed bone metastases. No 1p deletions were detected in the original tumour. GBM cells disclosed the EGFr(+) and p53(-) immunophenotype more characteristic of a primary GBM.

Germ cell tumors of the CNS in children: recent advances in therapy.

Primary germ cell tumors of the central nervous system are rare neoplasms, accounting for no more than 2% of all malignancies in children and young people under 20 in the Western hemisphere. They have unique features related to age at diagnosis and sites of origin, as well as race and gender predilection. Prognosis has been clearly shown to be strongly related to pathological classification as either pure germinoma or nongerminomatous germ cell tumor, although many of these lesions are comprised of mixed elements. The presence of serum or cerebrospinal fluid tumor marker elevation has been an essential determinant of response to treatment. Because of the deleterious effects of irradiation on the immature nervous system, investigators have used chemotherapeutic strategies that either reduce or eliminate radiation therapy. In this article, we review the most recent advances in therapy for CNS germ cell tumors in the pediatric population and highlight the importance of cooperative trials in this setting.

Oncogene expression in tumour cells of pediatric Hodgkin's disease in Argentina--correlation with Epstein Barr virus presence.

A new category of oncogenes regulating apoptosis, p53 and bcl-2, and the Epstein Barr virus (EBV) latent membrane protein-1 (LMP-1) have been related to Hodgkin's disease (HD) pathogenesis. We attempt to determine p53, mdm2, p21waf-1, bcl-2 and LMP-1 immunohistochemical expression in tissue sections from formalin-fixed, paraffin-embedded lymph node biopsies of pediatric HD. P53 was detected in the nucleus of Reed Sternberg cells and their variants (H-RS) in 68% of the HD cases. However, there was no statistically significant association with either clinical stages or with histological subtypes. P21waf-1, an indirect marker of p53 functional status, showed nuclear labelling of H-RS in all the studied cases. MDM2 co-expressed with p53 in 62% of the cases, suggesting that both proteins regulate one another, in HD by a self regulatory loop. Bcl-2 cytoplasmatic expression in H-RS was demonstrated in 65% of the cases. There was co-expression of bcl-2 and p53 in 51%, but it failed to correlate with a poor prognosis. LMP-1 labelling was shown in 51% of the cases, disclosing a statistically significant association with the under 6-year group (p = 0.005, Fisher's exact test). Since LMP-1 induces the expression of bcl-2 in vitro, the relation of both proteins was analysed and found to co-express in 15/37 cases, with a statistically significant association only in the under 6-year group (p = 0.001, Fisher's exact test). Abnormal accumulation of these oncoproteins in tumour cells could play a role in the pathogenesis of a subset of pediatric HD.

Epstein Barr virus in Argentine pediatric Hodgkin's disease.

Since Hodgkin's disease (HD) is an heterogeneous condition with diverse histological and epidemiological subgroups, it seemed worthwhile to investigate the Argentine pediatric pattern. Moreover, the presence of Epstein Barr virus (EBV) infection occurs at different ages depending on the development status of the country. Thus, it was interesting to assess the relation between EBV and HD in the Argentine pediatric population. The age distribution profile of our pediatric HD patients showed a peak in early childhood which declined towards adolescence, closely resembling EBV infection pattern. Male:female ratio of the studied population was 3.2:1 and the histological subtype distribution disclosed that mixed cellularity HD (MCHD) was the most common, an epidemiological profile shared with other developing countries. Fifty percent of assessed HD cases were associated with EBV, showing a significantly higher prevalence in the 3-6 years-old group, indicating a non-random distribution. EBV was also present in most of MCHD cases and in some nodular lymphocyte predominance HD (nLPHD) but entirely absent in nodular sclerosis HD (NSHD). Both EBV subtypes, namely EBV-1 and EBV-2, were detected in studied HD cases. EBV-HD association in the Argentine pediatric population reveals typical epidemiological features indicating EBV as the aetiologic agent or, alternatively as a cofactor in a considerable percentage of such HD cases.

Nuevas perspectivas en la actitud quirurgica ante el niño quemado / Surgical management of burned children: new perspectives

Desde el año 1970 en que Janzekovic preconizo el tratamiento quirurgico precoz de los niños con quemaduras darmicas profundas, podemos afirmar que stas se han convertido en una de las indicaciones quirurgicas por excelencia. En esta patologia, el incremento en las tasas de supervivencia la mejoria en los resultados van estrachamente unidos a una rapida ex resis de los tejidos lesionados y su sustitucion precoz por una cobertura cutanea definitiva. Se presenta la experiencia en el tratamiento quirurgico del niño quemado haciendo hincapi en le manejo de sustitutos temporales del pi (apositos biosintaticos y homoinjertos cutaneos) y coberturas definitivas (autoinjerto y cultivo de queratinocitos)

Nuevas perspectivas en la actitud quirurgica ante el niño quemado / Surgical management of burned children: new perspectives

Desde el año 1970 en que Janzekovic preconizo el tratamiento quirurgico precoz de los niños con quemaduras darmicas profundas, podemos afirmar que stas se han convertido en una de las indicaciones quirurgicas por excelencia. En esta patologia, el incremento en las tasas de supervivencia la mejoria en los resultados van estrachamente unidos a una rapida ex resis de los tejidos lesionados y su sustitucion precoz por una cobertura cutanea definitiva. Se presenta la experiencia en el tratamiento quirurgico del niño quemado haciendo hincapi en le manejo de sustitutos temporales del pi (apositos biosintaticos y homoinjertos cutaneos) y coberturas definitivas (autoinjerto y cultivo de queratinocitos)

Functional adrenal cortical tumors in pediatric patients: a clinicopathologic and immunohistochemical study of a long term follow-up series.

BACKGROUND: Controversy exists as to which variable is a reliable predictor of clinical outcome of adrenal cortical tumors in children. METHODS: Twenty patients with adrenal cortical tumors were studied. Tumor weight, histologic features, and percentage of proliferating cell nuclear antigen (PCNA/cyclin) in tumor cells were analyzed to determine the best predictor of clinical outcome. RESULTS: Eleven patients had Cushing's syndrome with virilization and 9 had virilization without Cushing's syndrome. The mean age at diagnosis was 7.1 +/- 5.2 years (range, 0.4-15.6 years). Sixteen patients, with good outcomes have been followed for 10.7 +/- 7.8 years (range, 3-23 years). All but two patients had a tumor weight of less than 100 g (185 g and 800 g, respectively) (mean 47.7 g +/- 46.4 g). Two patients with large tumors (weighing 1000 g and 780 g, respectively) had poor outcomes; 1 died 3 months after surgery with metastasis and the other presented with lung metastasis 18 months after surgery. Histologic features did not correlate with clinical outcome. Overall, PCNA stained cells were 6.96 +/- 8.2% (range, 0-32.5%). PCNA values were significantly lower in tumors of patients with good outcomes (P < 0.002). Within all tumors, we found a weak correlation between tumor weight and PCNA (r = 0.51; P < 0.02), but a better correlation was found between tumor weight and PCNA in patients with Cushing's syndrome (r = 0.70; P < 0.01). Patients with Cushing's syndrome had higher PCNA values than those with virilization syndrome (10.3 +/- 9.6% vs. 2.8 +/- 3.3%; P < 0.03). CONCLUSIONS: Our data show that small tumors (less than 100 g) are associated with good outcome; the two patients with the poorest prognosis had Cushing's syndrome and large tumors (more than 100 g). Histologic features are not adequate predictors of outcome and PCNA may be useful in tumors of patients with Cushing's syndrome, but this parameter should not be used alone. Two patients had virilization syndrome, large tumors (185 g and 800 g, respectively), and good outcomes, which contradicts with the concept that these tumors are usually associated with poor prognosis.

Presence of Epstein-Barr virus and strain type assignment in Argentine childhood Hodgkin's disease.

Epstein-Barr virus (EBV) has been implicated in the etiology of a large number of malignancies. Most recently several studies have linked EBV to Hodgkin's disease. In this report, formalin-fixed, paraffin-embedded tissues were collected retrospectively from 41 children with Hodgkin's disease treated at our hospital. Lymph node biopsies were examined for the presence of two virus-encoded latent proteins: latent membrane protein (LMP) and Epstein-Barr nuclear antigen-2 (EBNA-2), in Reed-Sternberg (RS) and Hodgkin (H) cells, by peroxidase immunolabeling. Nonisotopic Epstein-Barr encoded RNAs (EBERs) in situ hybridization was also performed and positive labeling in malignant cells was detected. Twenty specimens were EBER+/LMP+, 2 were EBER+/LMP-, and 19 were EBER-/LMP-. However, none of the 41 cases expressed EBNA-2. Twenty-two of 41 (54%) cases were EBV positive including 2 of 6 with lymphocyte predominance, 19 of 25 with mixed cellularity, 0 of 9 with nodular sclerosis, and 1 of 1 with lymphocyte depletion. In the age range of 2 to 6 years, 14 of 17 (82%) samples were EBV-positive, whereas only 8 of 24 (33%) samples from the age range of 7 to 15 years contained EBV. (P = .004), a two-tailed Fisher's test). In 17 samples, polymerase chain reaction amplification was performed using strain specific primers for exon sequences of the EBNA-3C gene of EBV. From 12 positive samples, 8 contained EBV-A and 4 EBV-B. These results support the hypothesis that EBV contributes to the pathogenesis of pediatric Hodgkin's disease, particularly in mixed cellularity Hodgkin's disease and in the younger group.

Epstein-Barr virus (EBV) latent membrane protein (LMP) in tumor cells of Hodgkin's disease in pediatric patients.

Twenty-nine out of 31 consecutive pediatric patients with Hodgkin's disease treated at our hospital from 1988 to 1992 were studied. The selection criterion was the availability of sufficient formalin-fixed, paraffin-embedded tissue for analysis. Patient age ranged from 3 to 15 years with a median age of 7 years. Lymph node biopsies were examined for the presence of Epstein-Barr virus (EBV)-encoded latent membrane protein (LMP) in malignant cells by peroxidase immunolabeling. LMP positivity was present in 10/15 (67%) of mixed cellularity, 1/6 (17%) of lymphocyte predominance, 0/7 (0%) of nodular sclerosis, and 1/1 (100%) of lymphocyte depletion. Positive cases by age range were: 10/12 (83%) for 3-6 years and 2/17 (11%) for 7-15 years. The association between EBV and Hodgkin's disease in children appeared to be more frequent in patients with mixed cellularity and those in the 3-6 age range, through examples of EBV-positive tumors were found in other histologic subtypes, stages and ages. Findings indicate that Hodgkin's disease in children is at least as strongly linked to EBV as in adults. Furthermore, we suggest that the EBV is associated with a subgroup of patients which can be defined on the basis of the age at diagnosis.

N-myc oncogene and urinary catecholamines in children with neuroblastoma.

This paper reports the analysis of N-myc amplification, urinary vanillylmandelic acid (VMA), and norepinephrine (NE) excretion and survival in 22 children with neuroblastoma and 7 with ganglio-neuroblastoma. Five patients had N-myc amplification (from 30 to more than 200 copies), all of whom had advanced-stage disease. The urinary excretion of VMA was normal in all of them, only one showed increased NE excretion. All patients with stage C-D disease and one copy of N-myc had increased VMA urinary excretion and increased (9/14) or normal (5/14) NE urinary excretion. All patients with stage A or B disease had one copy of N-myc. Half of them showed increased VMA urinary levels, while only 3/10 showed increased NE urinary values. Comparison of cumulative survival curves in relation to N-myc amplification and to VMA and NE urinary excretion showed a clear parallelism. Amplification of N-myc corresponded to normal VMA and NE urinary excretion, and was associated with the worst prognosis (P < 0.01), while increased VMA and/or NE excretion was found in patients with only one copy of N-myc.

Molecular epidemiology of Burkitt's lymphoma from South America: differences in breakpoint location and Epstein-Barr virus association from tumors in other world regions.

We have previously shown that the endemic (African) and sporadic (North American) forms of Burkitt's lymphoma (BL) differ at a molecular level. We have now extended our studies to the molecular epidemiology of BL in South America, specifically to two climatic regions: temperate (Argentina and Chile) and tropical (Brazil). We have examined the patterns of chromosomal breakpoint locations in 39 tumors with respect to geography and Epstein-Barr virus (EBV) association. The result of these analyses provide further support for the existence of pathogenetically distinct subtypes of BL in different world regions. The majority of breakpoints on chromosome 8 in South American BL (41%) occurred in the immediate flanking region of c-myc, ie, further 5' of the "typical" sporadic breakpoints, in the first exon/intron region, and further 3' of the "typical" endemic breakpoints, which are usually distant from c-myc. However, the distribution of breakpoints on chromosome 14 in tumors from the temperate and tropical regions of South America is similar to that observed in sporadic and endemic tumors. Interestingly, only one tumor with an unrearranged c-myc gene joined to the S mu region of chromosome 14 was observed. This combination was also rarely observed in our earlier series and presumably is either less readily generated by the mechanism that mediates 8;14 translocation or requires other, infrequent genetic changes to provide the necessary selective advantage for lymphomagenesis. The frequency of EBV association in South American BL (51%) is also intermediate with respect to tumors from the United States (30%) and Africa (100%). No correlation with the breakpoint location on chromosome 8 was discernable. Surprisingly, only 54% of tumors with breakpoint outside c-myc were EBV positive. This is in contrast to endemic tumors and suggests that any pathogenetic contribution of EBV is not dependent on breakpoint location, but is more likely to complement additional pathogenetic elements that differ in different world regions.