Publications by authors named "Luiz Fernando Lopes"

Germ cell tumors (GCTs) constitute diverse neoplasms arising in the gonads or extragonadal locations. Testicular GCTs (TGCTs) are the predominant solid tumors in adolescents and young men. Despite cisplatin serving as the primary therapeutic intervention for TGCTs, 10‑20% of patients with advanced disease demonstrate resistance to cisplatin‑based chemotherapy, and epithelial‑mesenchymal transition (EMT) is a potential contributor to this resistance.

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The TeLeo Program offers a free-access 2-year online learning program to support fellowship programs in pediatric oncology, enhance networking opportunities, and facilitate the exchange of context-specific, educational content within the pediatric oncology community in training in Latin America. In its first edition beginning in 2021, 185 fellows from 40 centers in 12 Latin American countries were enrolled. Additional courses for other healthcare professionals related to oncology in the region were produced to further support the program.

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Article Synopsis
  • Blood culture is a slow and often ineffective method for identifying pathogens in bloodstream infections, particularly concerning for pediatric oncology patients facing febrile neutropenia.
  • Two new High-Resolution Melting (HRM) assays were developed, showing excellent specificity and the ability to detect very low amounts of bacterial DNA, outperforming traditional blood culture methods.
  • The HRM assays demonstrated variable sensitivity in identifying pathogens from blood samples of pediatric cancer patients, indicating their potential as a quicker diagnostic tool for managing infections in this vulnerable group.
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microRNAs (miRNAs) are small endogenous noncoding RNAs, and alterations in their expression may contribute to oncogenesis. Discovering a unique miRNA pattern holds the potential for early detection and novel treatment possibilities in cancer. This study aimed to evaluate miRNA expression in pediatric patients with gonadal germ cell tumors (GCTs), focusing on characterizing the miRNA profiles of each histological subtype and identifying a distinct histological miRNA signature for a total of 42 samples of pediatric gonadal GCTs.

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Retinoblastoma, the most common intraocular tumor in childhood, still faces challenges in diagnosis and treatment, particularly in low- and middle-income countries. Identifying strategies to improve the time to diagnosis and access to treatment is crucial to enhance survival rates and preserve ocular health. We conducted a systematic review to identify interventions that have demonstrated potential in addressing these challenges.

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Background: Germ cell tumors (GCTs) comprise a rare and heterogeneous group of neoplasms presenting different clinical and histological characteristics, leading to a challenging scenario in clinical practice. Diffusion-weighted imaging (DWI) has been suggested as an indirect marker of tumor density and cellularity and could be used to monitor therapeutic response. However, its role in pediatric GCTs needs to be clarified.

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Ovarian germ cell tumors (OGCTs) are rare in adults; indeed, they occur predominantly in children, adolescents, and young adults, and they account for approximately 11% of cancer diagnoses in these groups. Because OGCTs are rare tumors, our current understanding of them is sparse; this is because few studies have investigated the molecular basis of pediatric and adult cancers. Here, we review the etiopathogenesis of OGCTs in children and adults, and we address the molecular landscape of these tumors, including integrated genomic analysis, microRNAs, DNA methylation, the molecular implications of treatment resistance, and the development of in vitro and in vivo models.

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Background/objectives: Surgery is the mainstay of therapy for children with ovarian immature teratoma (IT), whereas adults receive adjuvant chemotherapy, except those with stage-I, grade-1 disease. In Brazil, children with metastatic ovarian IT received postoperative chemotherapy. This practice variation allowed evaluation of the value of chemotherapy, by comparison of Brazilian patients with those in the United States and United Kingdom.

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Malignant extracranial germ cell tumors (GCTs) are rare in pediatric patients and are usually extremely sensitive to chemotherapy. Relapsed or refractory tumors, although rare, established the need for second-line therapies, including high-dose chemotherapy with autologous stem cell transplantation (HDCT/ASCT). However, there are few data on its use in children with GCTs.

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Background: Childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) has been associated with early-life exposures, including birth by cesarean section (C-section), and a deficit of social exposure (first child). These exposures as proxies for microbiome acquisition in infancy are essential to prime the immune system and restrain later dysregulated immune responses that can trigger ALL in susceptible individuals. We tested risk factors pertaining to immune stimulation that may impact BCP-ALL development.

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Article Synopsis
  • - Testicular germ cell tumors (TGCTs) are the most common cancers in young men, but about 10% of patients become resistant to the standard treatment, cisplatin (CDDP), leading to a need for new therapies.
  • - A study established a model for CDDP-resistant TGCT and used NanoString technology to analyze gene expression, discovering key genes linked to DNA repair and cell cycle regulation.
  • - The proteasome inhibitor MG-132 was found to kill TGCT cells and increase their sensitivity to CDDP, suggesting it could be a promising treatment for patients with CDDP-resistant tumors.
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5-Azacitidine has been used before stem cell transplantation in juvenile myelomonocytic leukaemia (JMML) patients. Recently, we have described immunophenotypic features in JMML at diagnosis. Here, our aim was to examine the changes in the immunophenotypic features during azacitidine treatment, correlating it with clinical response.

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This study aimed to evaluate the effects of purple grape juice consumption in pregnancy on oxidative stress parameters in rat fetuses. Twenty-four pregnant rats were divided into five groups: control group, indomethacin group (received a single dose of indomethacin in DG20), group grape juice DG14 (received an amount for 14 days/first and second gestational trim), group grape juice DG20 (received a dose throughout the gestational period), group grape juice two doses (received two doses, at morning and afternoon). On the 20th day of pregnancy (DG20), rats were anesthetized, and a cesarean section was performed to obtain the fetuses.

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Cancer is a leading cause of death by disease in children and the second most prevalent of all causes in adults. Testicular germ cell tumors (TGCTs) make up 0.5% of pediatric malignancies, 14% of adolescent malignancies, and are the most common of malignancies in young adult men.

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Pediatric osteosarcoma outcomes have improved over the last decades; however, patients who do not achieve a full resection of the tumor, even after aggressive chemotherapy, have the worst prognosis. At a genetic level, osteosarcoma presents many alterations, but there is scarce information on alterations at metabolomic levels. Therefore, an untargeted nuclear magnetic resonance metabonomic approach was used to reveal blood serum alterations, when samples were taken from 21 patients with osteosarcoma aged from 12-20 (18, 86%) to 43 (3, 14%) years before any anticancer therapy were collected.

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The diagnosis of juvenile myelomonocytic leukaemia (JMML) is based on clinical, laboratory and molecular features but immunophenotyping [multiparametric flow cytometry (MFC)] has not been used routinely. In the present study, we describe the flow cytometric features at diagnosis with special attention to the distribution of monocytic subsets and the relation between MFC and molecular subgroups. MFC was performed with an eight-colour platform based on Euroflow.

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Germ cell tumors (GCTs) are considered a rare disease but are the most common solid tumors in adolescents and young adults, accounting for 15% of all malignancies in this age group. The rarity of GCTs in some groups, particularly children, has impeded progress in treatment and biologic understanding. The most effective GCT research will result from the interrogation of data sets from historical and prospective trials across institutions.

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It has been suggested that bridging therapy with intensive chemotherapy and/or hypomethylating agents followed by hematopoietic stem cell transplantation (HSCT) can be valuable in the treatment of patients with myelodysplastic syndromes (MDS). However, the influence of this approach on HSCT outcomes remains poorly defined. Therefore, our objective was to investigate the influence of treatment before HSCT in patients with MDS.

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Objectives: Study the clinical characteristics of patients diagnosed with Ewing family tumors (EFTs) and survival analysis based on risk criteria and expression of the surface protein known as insulin-like growth factor (IGFR).

Methods: This was a retrospective cohort study based on clinical data from 77 patients diagnosed with EFTs treated by the Department of Pediatric Oncology at the Barretos Cancer Hospital in a period between 2003 and 2012. Biological samples of patients were examined for the presence of the surface receptor IGFR.

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Testicular germ cell tumors (TGCT) represent the second main cause of cancer-related death in young men. Despite high cure rates, refractory disease results in poor prognosis. Epigenetic reprogramming occurs during the development of seminomas and non-seminomas.

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Osteosarcoma (OS) is the most common primary bone cancer in childhood. OS is an aggressive disease, and metastatic patients evolve with very poor clinical outcomes. Genetically, OSs are extremely complex tumors, and the related metastatic process is not well understood in terms of the biology of the disease.

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Objective: To characterize the hearing loss after cancer treatment, according to the type of treatment, with identification of predictive factors.

Methods: Two hundred patients who had cancer in childhood were prospectively evaluated. The mean age at diagnosis was 6 years, and at the audiometric assessment, 21 years.

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Purpose: We describe the results of a risk-adapted, response-based therapeutic approach from the Brazilian GCT-99 study on germ cell tumors.

Patients And Methods: From May 1999 to October 2009, 579 participants were enrolled in the Brazilian GCT-99 study. Treatment, defined as specific chemotherapy regimen and number of cycles, was allocated by means of risk-group assignment at diagnosis with consideration for stage and primary tumor site.

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The abnormal activation of telomerase, codified by the telomerase reverse transcriptase (TERT) gene, is related to one of cancer hallmarks. Hotspot somatic mutations in the promoter region of TERT, specifically the c.-124:C>T and c.

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