Seroprevalence of IgG and IgM anti-SARS-CoV-2 among voluntary blood donors in Rio de Janeiro, Brazil

Background: In Brazil, mathematical models for deriving estimates and projections of COVID-19 cases have been developed without data on asymptomatic SARS-CoV-2 infection. We estimated the seroprevalence of antibodies to SARS-CoV-2 among blood donors in the State of Rio de Janeiro. Methods: Data were collected on 2,857 blood donors from April 14 to 27, 2020. We report the crude prevalence of antibodies to SARS-CoV-2, the weighted prevalence by the total state population, and adjusted prevalence estimates for test sensitivity and specificity. To establish the correlates of SARS-CoV-2 prevalence, we used logistic regression models. The analysis included period and site of blood collection, sociodemographic characteristics, and place of residence. Results: The proportion of SARS-Cov-2 positive tests without any adjustment was 4.0% (95% CI 3.3-4.7%), and the weighted prevalence was 3.8% (95% CI 3.1-4.5%). Further adjustment by test sensitivity and specificity produced lower estimates, 3.6% (95% CI 2.7-4.4%) and 3.3% (95% CI 2.6-4.1%), respectively. The variable most significantly associated with the crude prevalence was the period of blood collection: the later the period, the higher the prevalence. Regarding socio-demographic characteristics, the younger the blood donors, the higher the prevalence, and the lower the educational level, the higher the odds of a positive SARS-Cov-2 antibody. Similar results were found for the weighted prevalence. Discussion: Although our findings resulted from a convenience sample, they match some basic premises: the increasing trend over time, since the epidemic curve in the state is still on the rise; the higher prevalence among the youngest who are more likely to circulate; and the higher prevalence among the less educated as they have more difficulties in following the social distancing recommendations. Despite the study limitations, it is possible to infer that protective levels of natural herd immunity to SARS-CoV-2 are far from being reached in Rio de Janeiro

New ways to deal with known preanalytical issues: use of transilluminator instead of tourniquet for easing vein access and eliminating stasis on clinical biochemistry

Introduction: Tourniquet due venous stasis can alter both concentration and/or activity of several blood analytes, but is rarely regarded as an issue of laboratory variability. To overcome the problem transillumination devices (TD) have been proposed for a stasis-free phlebotomy. In this paper the use of a TD in place of tourniquet during blood collection has been evaluated. Materials and methods: Blood was collected from 250 volunteers divided in five homogenous groups of tourniquet times (G1: 30 sec, G2: 60 sec, G3: 90 sec, G4: 120 sec, G5: 180 sec) and compared to blood obtained using TD. All samples were analyzed for glucose (GLU), total protein (TP), albumin (ALB), triglycerides (TRIG), potassium (K), sodium (NA), phosphate (PHOS), calcium (CA), alkaline phosphatase (ALKP) and magnesium (MG). Results: In respect of TD, G1 did not show statistically significant increases in all clinical chemistry tests; G2 showed increases for GLU, TP, ALB, TRIG, K, CA, MG and ALKP. G3 and G4, showed no significant increase only for PHOS. G5 showed significant increases in all the tests evaluated. Moreo-ver, clinically significant variations were observed for TP, ALB, K and CA in G2 to G5; for NA in G3 to G5; for MG in G4 and G5; for GLU, TRIG, ALKP only in G5. Conclusions: These results support the application of TD in blood collection for routine clinical chemistry laboratory tests, suggesting its use should be more diffused

A Novel Assay for the Identification of NOTCH1 PEST Domain Mutations in Chronic Lymphocytic Leukemia

Aims. To develop a fast and robust DNA-based assay to detect insertions and deletions mutations in exon 34 that encodes the PEST domain of NOTCH1 in order to evaluate patients with chronic lymphocytic leukemia (CLL). Methods. We designed a multiplexed allele-specific polymerase chain reaction (PCR) combined with a fragment analysis assay to detect specifically the mutation c.7544_7545delCT and possibly other insertions and deletions in exon 34 of NOTCH1. Results. We evaluated our assay in peripheral blood samples from two cohorts of patients with CLL. The frequency of NOTCH1 mutations was 8.4% in the first cohort of 71 unselected CLL patients. We then evaluated a second cohort of 26 CLL patients with known cytogenetic abnormalities that were enriched for patients with trisomy 12. NOTCH1 mutations were detected in 43.7% of the patients with trisomy 12. Conclusions. We have developed a fast and robust assay combining allele-specific PCR and fragment analysis able to detect NOTCH1 PEST domain insertions and deletions

A Novel Assay for the Identification of NOTCH1 PEST Domain Mutations in Chronic Lymphocytic Leukemia

Aims. To develop a fast and robust DNA-based assay to detect insertions and deletions mutations in exon 34 that encodes the PEST domain of NOTCH1 in order to evaluate patients with chronic lymphocytic leukemia (CLL). Methods. We designed a multiplexed allele-specific polymerase chain reaction (PCR) combined with a fragment analysis assay to detect specifically the mutation c.7544 7545delCT and possibly other insertions and deletions in exon 34 of NOTCH1. Results. We evaluated our assay in peripheral blood samples from two cohorts of patients with CLL. The frequency of NOTCH1 mutations was 8.4% in the first cohort of 71 unselected CLL patients. We then evaluated a second cohort of 26 CLL patients with known cytogenetic abnormalities that were enriched for patients with trisomy 12. NOTCH1 mutations were detected in 43.7% of the patients with trisomy 12. Conclusions. We have developed a fast and robust assay combining allele-specific PCR and fragment analysis able to detect NOTCH1 PEST domain insertions and deletions

Titularização de crédito: um modelo para a banca em Portugal

Assiste-se hoje em dia a constantes mudanças nos mercados financeiros, resltantes do fenómeno da globalização, que teve o seu auge na década de 90 e irá prosseguir na próxima década em contornos e cosequências ainda hoje não totalmente defenidas. Paralelamente ocorrem, movimentos tendentes á desintermediação dos mercados e á competição entre todo o tipo de entidades, quer sejam financeiras ou não...

Melanocitoma do nervo óptico

Trabalho final de mestrado integrado em Medicina área científica de Oftalmologia, apresentado à Faculdade de Medicina da Universidade de CoimbraIntroduction: Melanocytoma is a designation implemented by Zimmerman and Garron in 1962, to describe heavily pigmented lesions of the optic disc, with asymptomatic and benign behavior. Its real prevalence is unknown, and frequently is a hazard finding during routine ophthalmic examination. The differential diagnosis with other pigmented lesions, namely the uveal malignant melanoma with extension to the optic disc, is difficult but imperative due to the different vital prognosis. Purpose: To present the prevalence of optic disc melanocytoma in a Portuguese population. Material and methods: Retrospective study of retinal photographs of a Portuguese population of 77,083 patients with diabetes mellitus, submitted to a screening program for diabetic retinopathy during the past ten years. Different morphological parameters are analyzed such as dimensions and location. In addiction, lesion characterization with several ancillary exams is performed. Results: The mean age at the time of diagnosis was 70 years. There was a male predominance (77.8%). Tumor was asymptomatic in all cases. The mean of greatest dimension was 1.6 mm. Visual acuity was normal in three cases and subnormal in one case, not tumor related. We found visual field defects in two cases. Tumor growth was documented in two cases, with a follow-up of 2 and 9 years, without malignant transformation. Conclusion: The prevalence of optic disc melanocytoma is 10/100,000 in Portuguese populationIntrodução: Melanocitoma é uma designação instituída por Zimmerman e Garron em 1962, que pretende descrever lesões densamente pigmentadas do disco óptico com comportamento assintomático e benigno. A sua prevalência exacta é desconhecida, sendo frequentemente um achado no exame oftalmológico de rotina. O diagnóstico diferencial com outras lesões pigmentadas, nomeadamente com o melanoma maligno uveal com extensão ao disco óptico é difícil, mas mandatório devido ao diferente prognóstico vital. Objectivo: Apresentar a prevalência de melanocitoma do disco óptico encontrada numa população portuguesa. Material e métodos: Estudo retrospectivo de registos retinográficos de uma população portuguesa, de 77.083 doentes, com diabetes mellitus, observada num programa de rastreio de retinopatia diabética durante os últimos 10 anos. São analisados diferentes parâmetros morfológicos, nomeadamente dimensões e localização, além da sua caracterização com vários meios complementares de diagnóstico. Resultados: A idade média na data de diagnóstico era de 70 anos. Houve um predomínio do sexo masculino (77,8%). O tumor era assintomático em todos os casos. A média da maior dimensão dos tumores era 1,6 mm. A acuidade visual era normal em três casos e subnormal num caso, não relacionado com o tumor. Foram observadas alterações campimétricas em dois casos. Foi documentado crescimento tumoral em dois casos, com seguimento de 2 a 9 anos, sem transformação maligna. Conclusão: A prevalência de melanocitoma do disco óptico é de 10/100.000, na população portugues

Improving Supply Chain Visibility With Artificial Neural Networks

The vulnerability of supply chains has been increasing and to properly respond to disruptions, visibility across the supply chain is required. This paper addresses these challenges by relying on the use of artificial neural networks to predict the capacity of a simulated supply chain to fulfil incoming orders and to anticipate which supply chain nodes will receive an order for the next period. To assess the effectiveness of the approach two experiments were conducted. The findings contribute to the understanding of on how artificial neural networks can be applied to reduce the vulnerability of supply chains

Roflumilast n-oxide associated with PGE2 prevents the neutrophil elastase-induced production of chemokines by epithelial cells

International audienceNeutrophil chemotaxis is involved in the lung inflammatory process in conditions such as chronic obstructive pulmonary disease (COPD). Neutrophil elastase (NE), one of the main proteases produced by neutrophils, has an important role in the inflammatory process via the release of chemokines from airway epithelial cells. It was recently shown that roflumilast N-oxide has therapeutic potential in COPD. The aim of the present study was to investigate roflumilast N-oxide's effect on NE-induced chemokine production and signaling pathways in A549 epithelial cells. A549 cells were incubated with NE for 30min, washed with PBS and then cultured for 2h (for measurement of mRNA expression) and 24h (for chemokine release) or for 5 to 30min (for protein phosphorylation assays). Prior to the addition of NE, cells were also pre-incubated with prostaglandin E2 (PGE2), alone and in combination with roflumilast N-oxide. Addition of NE was associated with elevated chemokine production by A549 cells and induction of the p38α pathway. In contrast when combined with PGE2, the roflumilast N-oxide had an additive effect on the inhibition of NE-induced chemokine release and p38α and other kinases activation. In conclusion, we demonstrated that NE is able to increase the release of chemokines from epithelial cells via the activation of p38α MAP-kinase and that roflumilast N-oxide when combined with PGE2 lowers NE-induced kinase activation and chemokine productio