WHO declared the novel coronavirus (COVID-19) outbreak a global pandemic on 11 March 2020. The establishment of standardized RT-qPCR protocols for respiratory secretions testing, as well as sharing of specimens, data, and information became critical. Here, we investigate the analytical performance of two interim RT-qPCR protocols (Charité and Centers for Disease Control (CDC)) for the qualitative detection of SARS-CoV-2 executed in a fully automated platform. Analytical specificity, PCR amplification efficiency, analytical sensitivity (limit of detection), and cross-reactivity were evaluated using contrived samples. The on-going accuracy was evaluated by retrospective analysis of our test results database (real clinical samples). N1, E, and a modified version of RdRP assays presented adequate analytical specificity, amplification efficiency, and analytical sensitivity using contrived samples. The three assays were applied to all individuals who requested the SARS-CoV-2 molecular test assay in our laboratory and it was observed that N1 gave more positive results than E, and E gave more positive results than RdRP (modified). The RdRP and E were removed from the test and its final version, based on N1 assay only, was applied to 30,699 Brazilian individuals (from 19 February 2020 to 8 May 2020). The aggregated test results available in the database were also presented.

Organotins are a group of chemical compounds that have a tin atom covalently bound to one or more organic groups. The best-studied organotin is tributyltin chloride, which is an environmental pollutant and an endocrine disruptor. Tributyltin chloride has been shown to bind to PPARγ/RXRα and induces adipogenesis in different mammalian cells. However, there are few studies with other organotin compounds, such as dibutyltins. The aim of this study was to investigate the effect of dibutyltins diacetate, dichloride, dilaurate, and maleate on the transcriptional activity of the nuclear PPARγ and RXRα receptors, and on adipogenesis and inflammation. Analogous to tributyltin chloride, in reporter gene assay using HeLa cells, we observed that dibutyltins diacetate, dichloride, dilaurate, and maleate are partial agonists of PPARγ. Unlike tributyltin chloride, which is a full agonist of RXRα, dibutyltins dichloride and dilaurate are partial RXRα agonists. Additionally, the introduction of the C285S mutation, which disrupts tributyltin chloride binding to PPARγ, abrogated the dibutyltin agonistic activity. In 3T3-L1 preadipocytes, all dibutyltin induced adipogenesis, although the effect was less pronounced than that of rosiglitazone and tributyltin chloride. This adipogenic effect was confirmed by the expression of adipogenic markers Fabp4, Adipoq, and Glut4. Exposure of 3T3-L1 cells with dibutyltin in the presence of T0070907, a specific PPARγ antagonist, reduced fat accumulation, suggesting that adipogenic effect occurs through PPARγ. Furthermore, dibutyltins dichloride, dilaurate, and maleate inhibited the expression of proinflammatory genes in 3T3-L1 cells, such as Vcam1, Dcn, Fn1, S100a8, and Lgals9. Additionally, in RAW 264.7 macrophages, tributyltin chloride and dibutyltin dilaurate reduced LPS-stimulated TNFα expression. Our findings indicate that dibutyltins diacetate, dichloride, dilaurate, and maleate are PPARγ partial agonists and that dibutyltins dichloride and dilaurate are also partial RXRα agonists. Furthermore, dibutyltins induce adipogenesis in a PPARγ-dependent manner and repress inflammatory genes in 3T3-L1 and RAW 264.7 cells. Although dibutyltins display some partial PPARγ/RXRα agonistic effects, the translation of cell-based results assays into in vivo effects on inflammation and insulin resistance is not entirely known. Nevertheless, further studies are necessary to address their effects in different periods of life and to elucidate the actions of organostanic compounds in whole-body context.

The World Health Organization declared that COVID-19 outbreak constituted a Public Health Emergency of International Concern and the development of reliable laboratory diagnosis of SARS-CoV-2 became mandatory to identify, isolate and provide optimized care for patients early. RT-qPCR testing of respiratory secretions is routinely used to detect causative viruses in acute respiratory infection. RT-qPCR in-house protocols to detect the SARS-CoV-2 have been described. Validations of these protocols are considered a key knowledge gap for COVID-19, especially if executed in a high throughput format. Here, we investigate the analytical sensitivity and specificity of two interim RT-qPCR protocols for the qualitative detection of SARS-CoV-2 executed in a fully automated platform. Under our conditions, the N1 and RdRP (modified) showed the highest analytical sensitivity for their RNA targets. E assay, in its original concentration, was considered a tertiary confirmatory assay. Taken together, N1, RdRP (optimized) and E presented appropriated analytical sensibility and specificity in our automated RT-qPCR workflow for COVID-19 virus, E being at least 4-fold less sensitive than the others. This study highlights the importance of local validation of in-house assays before its availability to the population. The use of the synthetic RT-qPCR target to investigate novel assays diagnostic parameters in automated workflows is a quick, simple effective way to be prepared for upcoming threats. The proposed assay detected the fisrt SARS-CoV-2 infection in Brazilian Central-West.. CC-BY 4.0 International license It is made available under a author/funder, who has granted medRxiv a license to display the preprint in perpetuity.is the (which was not peer-reviewed) The copyright holder for this preprint .

In February 2020, our laboratory started to offer a RT-qPCR assay for the qualitative detection of severe acute respiratory syndrome coronavirus 2. A few months after the assay was released to our patients, some materials, reagents, and equipment became in short supply. Alternative protocols were necessary in order to avoid stopping testing to the population. However, the suitability of these alternatives needs to be validated before their use. Here, we investigated if saliva is a reliable alternative specimen to nasopharyngeal swabs; if 0.45% saline is a reliable alternative to guanidine hydrochloride as a collection viral transport media; the stability of SARS-COV-2 in guanidine hydrochloride and in 0.45% saline for 10 and 50 days at room temperature; and if the primers/probe concentration and thermocycling times could be reduced so as to overcome the short supply of these reagents and equipment, without a significant loss of the assay performance. We found that saliva is not an appropriated specimen for our method—nasopharyngeal swabs perform better. Saline (0.45%) and guanidine hydrochloride have a similar SARS-CoV-2 diagnostic capability as tube additives. Reliable SARS-CoV-2 RNA detection can be performed after sample storage for 10 days at room temperature (18–23 °C) in both 0.45% saline and guanidine hydrochloride. Using synthetic RNA, and decreasing the concentration of primers by five-fold and probes by 2.5-fold, changed the assay limit of detection (LOD) from 7.2 copies/reaction to 23.7 copies/reaction and the subsequent reducing of thermocycling times changed the assay LOD from 23.7 copies/reaction to 44.2 copies/reaction. However, using real clinical samples with Cq values ranging from ~12.15 to ~36.46, the results of the three tested conditions were almost identical. These alterations will not affect the vast majority of diagnostics and increase the daily testing capability in 30% and increase primers and probe stocks in 500% and 250%, respectively. Taken together, the alternative protocols described here overcome the short supply of tubes, reagents and equipment during the SARS-CoV-2 pandemic, avoiding the collapse of test offering for the population: 105,757 samples were processed, and 25,156 SARS-CoV-2 diagnostics were performed from 9 May 2020 to 30 June 2020.

ObjectiveIn early 2015, an outbreak of an acute exanthematous illness with dengue-like symptoms occurred in northeastern Brazil. By the end of the same year, an unexpected increase in the number of cases of microcephaly was observed in the region. The microcephaly outbreak cause was unknown and rumors pointing to various potential causes arose. Since we were unaware at the time if this scenario would attract the interest of the broader scientific community, due to the neglected regions associated and as often happens with many others health conditions related to infectious diseases in Latin America. This coupled with the fact that diagnostic testing for Zika virus was not available, prompted us to design a study that could demonstrate the correlation between the development of an exanthematous illness with Zika-like symptoms during pregnancy and the delivery of a newborn with congenital microcephaly.ResultsMothers who experienced symptoms associated with the Zika virus during pregnancy had 10 times higher odds of delivering newborns with congenital microcephaly when compared with mothers who did not exhibit Zika-like symptoms. Thus, the acute exanthematous illness outbreak could be associated with the congenital microcephaly outbreak. We could not distinguish which virus caused the acute exanthematous illness in the study subjects (Zika, dengue or chikungunya), but these results could help to reduce the misquided speculation in regards to the cause of the microcephaly and could have expedited public health policies intended for controlling the mosquito vector. In addition to the lower head circumference, microcephalic neonates also had lower thoracic circumference, lower height and lower weight compared to non-microcephalic babies suggesting intrauterine growth restriction. Additionally, we found borderline association between mothers classified as homemakers and, who had past dengue infections with microcephaly. Prior contraction of dengue virus seems to play a role in the risk for the condition reflecting the domestication of the Aedes Aegypti and the enhancement of the Zika virus infection by dengue antibodies, respectively. The limitations of this study are: (a) participants recall bias, (b) absence of laboratory test results for Zika virus and other arboviruses and (c) incomplete test results for other pathogens that could lead to microcephaly.The study protocol was registered at ClinicalTrial.gov under the identifier NCT02741882. Registered on April 13th, 2016Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-017-2796-1) contains supplementary material, which is available to authorized users.

The cell-free genomic DNA (gDNA) concentration in serum ranges from 1500 to 7500 copies/mL within 2 h after phlebotomy (6–24 times the concentration observed in plasma). Here, we aimed to evaluate the gDNA size distribution in serum with time after coagulation and to test if crude serum can be directly used as a source of gDNA for qPCR. Next, we investigated if single nucleotide polymorphisms (SNPs) could be genotyped directly from the crude serum isolated from capillary blood using a hand-powered paper centrifuge. All tested PCR targets (65, 100, 202 and 688 base pairs) could be successfully amplified from DNA extracted from serum, irrespective of their amplicon size. The observed qPCR quantitation cycles suggested that the genomic DNA yield increased in serum with incubation at room temperature. Additionally, only 65 and 101 base pair qPCR targets could be amplified from crude serum soon after the coagulation. Incubation for 4 days at room temperature was necessary for the amplification of PCR targets of 202 base pairs. The 688 base pair qPCR target could not be amplified from serum directly. Lastly, serum was successfully separated from capillary blood using the proposed paper centrifuge and the genotypes were assigned by testing the crude serum using allele-specific qPCR, producing small amplicon sizes in complete agreement with the genotypes assigned by testing the DNA extracted from whole blood. The serum can be used directly as the template in qPCR for SNP genotyping, especially if small amplicon sizes are applied. This shortcut in the SNP genotyping process could further molecular point-of-care diagnostics due to elimination of the DNA extraction step.

Sometimes, the presentation of some diseases can be fulminating. The authors present the case of a 51-year- old male brought to the emergency department visibly drunk and complaining of abdominal pain. Immediately, the diagnosis of hemorrhagic shock due to an accentuated drop of the hemoglobin level was made. After stabilization, he underwent a computed tomography of the abdomen, revealing a hepatocellular carcinoma with rupture of the Glisson capsule and massive intraperitoneal hemorrhage. With this case, the authors want to bring attention to a rare first presentation of hepatocellular carcinoma with a catastrophic result.

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