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This work presents a low-cost transcription loop-mediated isothermal amplification (RT-LAMP) instrument for nucleic acid detection, employing an Arduino Nano microcontroller. The cooling system includes customized printed circuit boards (PCBs) that serve as electrical resistors and incorporate fans. An aluminum block is designed to accommodate eight vials. The system also includes two PCB heaters-one for sample heating and the other for vial lid heating to prevent condensation. The color detection system comprises a TCS3200 color 8-sensor array coupled to one side of the aluminum heater body and a white 8-LED array coupled to the other side, controlled by two Multiplexer/Demultiplexer devices. LED light passes through the sample, reaching the color sensor and conveying color information crucial for detection. The top board is maintained at 110 ± 2 °C, while the bottom board is held at 65 ± 0.5 °C throughout the RT-LAMP assay. Validation tests successfully demonstrated the efficacy of the colorimetric RT-LAMP reactions using SARS-CoV-2 RNA amplification as a sample viability test, achieving 100% sensitivity and 97.3% specificity with 66 clinical samples. Our instrument offers a cost-effective (USD 100) solution with automated result interpretation and superior sensitivity compared to visual inspection. While the prototype was tested with SARS-CoV-2 RNA samples, its versatility extends to detecting other pathogens using alternative primers, showcasing its potential for broader applications in biosensing.

This article describes the fabrication of a low-cost Polymerase Chain Reaction (PCR) instrument to detect diseases. In order to reduce the instrument price and simplify construction we developed an alternative fabrication process, transforming conventional printed circuit boards (PCB) in heating elements, avoiding the use of aluminum heating/cooling blocks and Peltier devices. To cool down the reaction a simple computer fan was used. The vial holder was fabricated using two double side PCB boards assembled in a sandwich-like configuration. The bottom PCB has a resistance of 0.9 Ω used to heat the reaction mix, while the top layer has a resistance of 1.1 Ω to heat the vial body, preventing vapor condensation. The top board was maintained at ~ 110 ± 1 °C during all cycles. The final device was able to heat and cool down the reaction at rates of ~ 2.0 °C/s, a rate comparable to commercial thermocyclers. An SMD NTC thermistor was used as temperature sensors, and a PID (proportional-integral-derivative) control algorithm was implemented to acquire and precisely control the temperature. We also discuss how the instrument is calibrated. The device was tested successfully for the amplification of T. pallidum (Syphilis) bacterial DNA and Zika virus RNA samples, showing similar performance to a commercial PCR instrument.

Cafe-au-lait maculae (CALM) are frequently observed in humans, and usually are present as a solitary spot. Multiple CALMs are present in a smaller fraction of the population and are usually associated with other congenital anomalies as part of many syndromes. Most of these syndromes carry an increased risk of cancer development. Previous studies have indicated that minor congenital anomalies may be more prevalent in children with cancer. We investigated the prevalence of CALMs in two samples of Brazilian patients with childhood solid tumors, totaling 307 individuals. Additionally, 176 school children without diagnosis of cancer, or of a cancer predisposing syndrome, were investigated for the presence of CALMs. The prevalence of solitary CALM was similar in both study groups (18% and 19%) and also in the group of children without cancer. Multiple CALMs were more frequently observed in one of the study groups (Z = 2.1). However, when both groups were analyzed together, the significance disappeared (Z = 1.5). The additional morphological abnormalities in children with multiple CALMs were analyzed and compared to the findings observed in the literature. The nosologic entities associated with CALMs are reviewed.

Objectives: Childhood cancer mortality has substantially declined worldwide as a result of significant advances in global cancer care. Because limited information is available in Brazil, we analyzed trends in childhood cancer mortality in five Brazilian regions over 29 years., Methods: Data from children 0-14 years old were extracted from the Health Mortality Information System for 1979 through 2008. Age-adjusted mortality rates, crude mortality rates, and age-specific mortality rates by geographic region of Brazil and for the entire country were analyzed for all cancers and leukemia. Mortality trends were evaluated for all childhood cancers and leukemia using joinpoint regression., Results: Mortality declined significantly for the entire period (1979-2008) for children with leukemia. Childhood cancer mortality rates declined in the South and Southeast, remained stable in the Middle West, and increased in the North and Northeast. Although the mortality rates did not unilaterally decrease in all regions, the age-adjusted mortality rates were relatively similar among the five Brazilian regions from 2006-2008., Conclusions: Childhood cancer mortality declined 1.2 to 1.6% per year in the South and Southeast regions.

Wilms tumour (WT) is a paediatric kidney tumour, composed of blastemal, epithelial and stromal cells, with a relapse rate of approximately 15%. Long-term survival for patients with relapse remains approximately 50%. Current clinical and molecular research is directed towards identifying prognostic factors to define the minimal and intensive therapy for successful treatment of children with low and high risk of relapse, respectively. Blastemal component presents a high level of aggressiveness and responsiveness to chemotherapy. To identify molecular prognostic markers that are predictive of chemotherapy sensitivity in tumour relapse, blastemal-enriched samples from stage III and IV WT, from patients with relapse or without relapse, were analysed for 4608 human genes immobilised on a customised cDNA platform. These analyses revealed 69 differentially expressed genes, and the top nine genes were further evaluated by qRT-PCR in the initial WT samples. TSPAN3, NCOA6, CDO1, MPP2 and MCM2 were confirmed to be down-regulated in relapse WT, and TSPAN3 and NCOA6 were also validated in an independent sample group. Protein expression of MCM2 and NCOA6 were observed in 38% (13 out of 34) and 28% (9 out of 32), respectively, of independent stage III and IV WT blastema samples, without association with relapse. However, a significant association between MCM2 positive staining and chemotherapy as first treatment suggests the involvement of MCM2 with drug metabolism in WT blastemal cells., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Background: The loss of a child is considered the hardest moment in a parent's life. Studies addressing length of survival under pediatric palliative care are rare. The aim of this study was to improve a survival prediction model for children in palliative care, as accurate information positively impacts parent and child preparation for palliative care., Procedure: Sixty-five children referred to a pediatric palliative care team were followed from August 2003 until December 2006. Variables investigated (also included in previous studies) were: diagnosis, home care provider, presence of anemia, and performance status score given by the home care provider. Clinical variables such as symptom number were also used to test the score's ability to predict survival., Results: The length of survival prognostic score was validated using the above variables. The number of symptoms at transition to palliative care does not improve the score's predictive ability. The sum of the single scores gives an overall score for each patient, dividing the population into three groups by probability of 60-day survival: Group A 80.0%, Group B 38.0%, and Group C 28.5% (P < 0.001)., Conclusion: A pediatric palliative care score based on easily accessible variables is statistically significant in multivariate analysis. Factors that increase accuracy of life expectancy prediction enable adequate information to be given to patients and families, contributing to therapeutic decision-making issues.

Acute leukemia is the most frequent cancer in children. Recently, a new hypothesis was proposed for the pathogenesis of childhood acute lymphoblastic leukemia (ALL). The so-called 'adrenal hypothesis' emphasized the role of endogenous cortisol in the etiology of B-cell precursor ALL. The incidence peak of ALL in children between 3 to 5 years of age has been well documented and is consistent with this view. The adrenal hypothesis proposes that the risk of childhood B-cell precursor ALL is reduced when early childhood infections induce qualitative and quantitative changes in the hypothalamus-pituitary-adrenal axis. It suggests that the increased plasma cortisol levels would be sufficient to eliminate all clonal leukemic cells originating during fetal life. Because Brazil is a continental and tropical country, the exposure to infections is diversified with endemic viral and regionally non-viral infections, with some characteristics that support the recent adrenal hypothesis. Here we discuss this new hypothesis in terms of data from epidemiological studies and the possible implications of the diversity of infections occurring in Brazilian children.

Cancer patients receiving chemotherapy are exposed to high doses of cytotoxic and genotoxic drugs which, in some cases, can lead to treatment related leukemia. Since this only occurs in a minority of patients, however, it is possible some individuals are predisposed due to genetic polymorphisms in genes for enzymes that mediate drug metabolism. To address this possibility we measured the genotoxicity of chemotherapeutic agents in patients receiving treatment for ALL by the frequency of the Vgamma/Jbeta trans-rearrangement in their peripheral blood leukocytes and compared this with CYP3A4 genotype. CYP3A4 is the most abundant of the cytochrome P450 (CYP) enzyme in the liver and intestine which contains a common -392A>G substitution in the promoter region (CYP3A4*1B allele). We found a significant increase in the frequency of rearrangements during chemotherapy only in patients homozygous for the wild type CYP3A4*1A allele. This provides a direct link between CYP3A4 genotype and susceptibility to drug genotoxicity thus strengthening the possibility that predisposition to treatment related leukemia may be measurable by simple genetic testing.

Background: This report describes the clinical characteristics of children and adolescents bearers of oncological disease who were admitted to PICU with severe sepsis and septic shock. The predicting factors for mortality and for need of pulmonary mechanical ventilation were also determined., Methods: Thirty-three children diagnosed with severe sepsis and septic shock were evaluated prospectively at the PICU of Hospital do Câncer between June and December of 2001., Results: Thirty-three admissions were analyzed during this period; ages ranged from 1 to 23 years; 16 (48%) were boys and 17 (52%) were girls. Twenty patients had leukemia/lymphoma and 13 patients had solid tumors. Twenty-eight patients had a diagnosis of infectious diseases. In 73% of the patients, infection germs were isolated and gram negative organisms were responsible for 67% of the samples. Respiratory support was necessary for 18 patients (54%), inotropic support for 22 (67%) and dialysis for four patients. The mortality rate was of 41% for patients who needed inotropic support, of 69% for those requiring respiratory support and of 100% for those with an indication for dialysis. The overall mortality rate was of 27%., Conclusions: This research suggests that early intensive treatment for children with cancer exhibiting severe sepsis and/or septic shock could be an important factor to influence the mortality rate of these patients. Moreover, that noninvasive ventilation could be an option to reduce endotracheal intubation and invasive ventilation.

OBJECTIVE: To describe a case of a congenital hepatic hemangioma treated with surgery. METHODS: We report the case of a 6-day-old boy who presented a giant hepatic hemangioma, and describe its evolution. RESULTS: The child developed hemodynamic instability secondary to consumption coagulopathy and respiratory failure. The image studies were inconclusive. He was submitted to surgery with complete resection of the tumor. Pathology confirmed it was hemangioma. The child was discharged after 15 days and is well, without symptoms. CONCLUSIONS: Hepatic hemangiomas should be treated conservatively, with surgery reserved for intractable cardiac failure and/or refractory consumptive coagulopaty.