Low-cost, facile droplet modification of screen-printed arrays for internally validated electrochemical detection of serum procalcitonin.

This manuscript presents the design and facile production of screen-printed arrays (SPAs) for the internally validated determination of raised levels of serum procalcitonin (PCT). The screen-printing methodology produced SPAs with six individual working electrodes that exhibit an inter-array reproducibility of 3.64% and 5.51% for the electrochemically active surface area and heterogenous electrochemical rate constant respectively. The SPAs were modified with antibodies specific for the detection of PCT through a facile methodology, where each stage simply uses droplets incubated on the surface, allowing for their mass-production. This platform was used for the detection of PCT, achieving a linear dynamic range between 1 and 10 ng mL-1 with a sensor sensitivity of 1.35 × 10-10 NIC%/ng mL-1. The SPA produced an intra- and inter-day %RSD of 4.00 and 5.05%, with a material cost of £1.14. Internally validated human serum results (3 sample measurements, 3 control) for raised levels of PCT (>2 ng mL-1) were obtained, with no interference effects seen from CRP and IL-6. This SPA platform has the potential to offer clinicians vital information to rapidly begin treatment for "query sepsis" patients while awaiting results from more lengthy remote laboratory testing methods. Analytical ranges tested make this an ideal approach for rapid testing in specific patient populations (such as neonates or critically ill patients) in which PCT ranges are inherently wider. Due to the facile modification methods, we predict this could be used for various analytes on a single array, or the array increased further to maintain the internal validation of the system.

Diagnostic value of heparin-binding protein in the cerebrospinal fluid for purulent meningitis in children

This study aimed to investigate the diagnostic value of heparin-binding protein (HBP) in the cerebrospinal fluid of children with purulent meningitis (PM). This study included 118 children with PM diagnosed at our hospital from January 2018 to January 2020, 110 children with viral meningitis (VM) and 80 children with suspected meningitis who were ruled out by cerebrospinal fluid (CSF) analysis during the same period. HBP and white blood cell (WBC) count in the CSF, and inflammatory factors, including C-reactive protein (CRP), tumor necrosis factor (TNF)-α, and procalcitonin (PCT), were measured. Receiver-operator characteristic curves were used to analyze the predictive value of HBP, CRP, PCT, and TNF-α levels in the diagnosis of PM by CSF analysis. HBP levels in the CSF of children with PM were higher, while the CRP and serum PCT and TNF-α levels were elevated in all groups (P<0.05). In addition, HBP levels in the CSF were more accurate for the diagnosis of PM than traditional diagnostic indexes. HBP levels in the CSF can be used as an important reference for early diagnosis of PM.

Promotion of technological development and determination of biotechnology trends in five selected Latin American countries: an analysis based on PCT patent applications

Background: Science and technology are two desirable elements for the economic and social development of a country. Biotechnology has a particularly important potential for economic development. Nevertheless, patent production in Latin America remains underdeveloped, which creates the need to analyze its trend and the efforts made to promote patent production. Therefore, the purpose of this study was, on the one hand, to determine trends in biotechnology-related PCT (Patent Cooperation Treaty) applications in Chile, Mexico, Argentina, Brazil, and Cuba from 1999 to 2015, and, on the other hand, to determine whether there is a relationship between the gross domestic expenditure on research and experimental development as a percentage of gross domestic product (GERD/GDP) and PCT applications for biotechnological inventions from 2007 to 2015 (in this case, the period under study was limited from 2007 to 2015, due to data availability for GERD/GDP in the five selected countries). Results: The first part of this study shows that the growth in biotechnology PCT applications has been moderate and gradual and the trend was fitted to a linear model. The second set of results shows that GERD/GDP is associated with biotechnology-related PCT applications issued during the study period with a significance level of α = 0.01. Conclusions: Even though results indicate a gradual and modest progress, it is necessary that these five representative Latin American nations continue acting toward the protection of intellectual property in the area of biotechnology, especially by configuring strategies for further progress based on investments on research and development.

Comparison of serum PCT and CRP levels in patients infected by different pathogenic microorganisms: a systematic review and meta-analysis

To avoid the abuse and misuse of antibiotics, procalcitonin (PCT) and C-reactive protein (CRP) have been used as new approaches to identify different types of infection. Multiple databases were adopted to search relevant studies, and the articles that satisfied the inclusion criteria were included. Meta-analyses were conducted with Review Manager 5.0, and to estimate the quality of each article, risk of bias was assessed. Eight articles satisfied the inclusion criteria. The concentrations of both PCT and CRP in patients with bacterial infection were higher than those with non-bacterial infection. Both PCT and CRP levels in patients with G− bacterial infection were higher than in those with G+ bacterial infection and fungus infection. In the G+ bacterial infection group, a higher concentration of CRP was observed compared with fungus infection group, while the difference of PCT between G+ bacterial infection and fungus infection was not significant. Our study suggested that both PCT and CRP are helpful to a certain extent in detecting pneumonia caused by different types of infection.

The expression patterns of bromelain and AcCYS1 correlate with blackheart resistance in pineapple fruits submitted to postharvest chilling stress.

Blackheart is a physiological disorder induced by postharvest chilling storage during pineapple fruit export shipping. The aim of this study was to check the involvement of bromelain, the cysteine protease protein family abundantly present in pineapple fruits, and AcCYS1, an endogenous inhibitor of bromelain, in the development of blackheart. For this we checked the response to postharvest chilling treatment of two pineapple varieties (MD2 and Smooth Cayenne) differing in their resistance to blackheart. Quantitative RT-PCR analyses showed that postharvest chilling treatment induced a down-regulation of bromelain transcript accumulation in both varieties with the most dramatic drop in the resistant variety. Regarding AcCYS1 transcript accumulation, the varieties showed opposite trends with an up-regulation in the case of the resistant variety and a down-regulation in the susceptible one. Taken together our results suggest that the control of bromelain and AcCYS1 expression levels directly correlates to the resistance to blackheart development in pineapple fruits.

Procalcitonina como marcador de procesos infecciosos en cirugía: Conceptos actuales / Procalcitonin as marker of infectious processes in surgery: Current concepts

Objetivo: Revisar conceptos actuales relacionados a la procalcitonina (PCT) para el diagnóstico y seguimiento de infecciones. Sede: Unidad de terapia intensiva Hospital Médica Sur. Diseño: Revisión de la literatura. Material y métodos: Se realizó una búsqueda en la literatura con las palabras clave PCT, infección, cirugía y antibióticos, en los buscadores Ovid, Springer, Sciencedirect, EbscoHost y Pubmed para responder las siguientes preguntas: ¿Qué tan útil es la PCT para el diagnóstico de infección y sepsis en diferentes escenarios quirúrgicos?, ¿qué impacto tiene como factor pronóstico?, ¿en qué guías se ha incluido como parte del algoritmo diagnóstico y de toma de decisiones para iniciar, de-escalar y suspender antibióticos? Resultados: De los 31 artículos incluidos en esta revisión, siete son metaanálisis, siete revisiones sistemáticas, cuatro estudios de no inferioridad, cuatro estudios de cohorte multicéntricos longitudinales, cuatro estudios observacionales experimentales y cinco estudios de casos y controles. Con base en los estudios evaluados, la procalcitonina mostró ser un marcador útil para el diagnóstico de infecciones y sepsis, con una sensibilidad del 75% (95% IC 67-76), especificidad del 80% (95% IC 76-91) con un área bajo la curva de 0.78 (95% IC 0.73-0.83). La especificidad se incrementa a 93.7% (95% IC 0.85-0.97) con puntos de corte por arriba de 2 ng/ml. La terapia antimicrobiana dirigida por PCT disminuye de manera significativa los días de exposición a antibiótico. Conclusiones: Con base en la evidencia científica, la PCT se ha posicionado como un buen marcador para el diagnóstico de infecciones bacterianas y para tomar decisiones en cuanto a la duración de la terapia antimicrobiana.

Objective: To review current concepts related to procalcitonin (PCT) for the diagnosis and follow-up of infections. Setting: Intensive care unit of the Hospital Médica Sur in Mexico City. Design: Review of the literature. Material and methods: We performed literature mining, using as keywords: PCT, infection, surgery and antibiotics, in the following databases: Ovid, Springer, Sciencedirect, EbscoHost, and PubMed, to be able to respond to the following questions: How useful is PCT for the diagnosis of infection and sepsis in different surgical scenarios, what impact does it have as prognostic factor? Which guidelines have included PCT as part of the diagnostic algorithm and as a tool for the decision to start, down-scale, and suspend antibiotics? Results: Of the 31 articles included in this review, seven corresponded to meta-analysis, seven to systematic reviews, four to non-inferiority studies, four to cohort multicentric, longitudinal studies, four to observational studies, and five to case-control studies. Based on the reviewed literature, procalcitonin revealed to be a useful marker for the diagnoses of infections and sepsis, with a 75% sensitivity (95% IC 67-76), 80% specificity (95% IC 76-91), with an area below the curve of 0.78 (95% IC 0.73-0.83). Specificity increases to 93.7% (95% IC 0.85-0.97) with cut-off points above 2 ng/ml. PCT-guided antimicrobial therapy diminishes significantly the days of antibiotic exposure. Conclusions: Based on the scientific evidence, PCT has been positioned as a good biomarker for the diagnosis of bacterial infections and to decide on the duration of antimicrobial therapy.

Determinação do sexo do feto através de uma nova técnica não invasiva baseada em PCR / Determination of fetal sex by a new PCR method non invasive

A determinação do sexo do feto é geralmente realizada pelo procedimento de ultra-som que ocorre no segundo trimestre da gestação, sendo que, quando realizado antes da 13ª semana, esse método se mostra muito incerto.Técnicas moleculares utilizando o PCR já foram descrita, e possuem maior sensibilidade na determinação do sexo. Dentre estas técnicas existentes, as invasivas consistem em amniocentese ou coleta de amostra de vilo coriônico, seguida de PCR para determinar osexo e que representam em aumento de risco na gravidez e as técnicas não invasivas que conseguem detectar o DNA fetal no sangue periférico materno. Foi desenvolvida em nosso laboratório uma técnica capaz de detectar o sexo fetal nas primeiras semanas de gestaçãocom alto índice de acerto. A técnica consistiu em desenhar iniciadores que anelassem em regiões repetitivas espalhadas no cromossomoY e “PCR Nested” para aumentar a acurácia do exame. Os resultados demonstraram que a técnica possui sensibilidade e especificidade de 100%. Além disso, a PCR foi capaz de detectar em uma diluição seriada de uma amostra de DNA genômico masculina, previamente quantificada, a presença do cromossomo Y em amostrascontendo apenas 100 femtogramas de DNA.

The determination of fetal sex is currently carried out by ultrasound that is usually performed in the second trimester. However, it is inaccurate before 13th week of gestation. Molecular techniques such as PCR already had been described and were successful of fetal gender. Among these techniques, there are invasive methods: chorionic villus sampling and amniocentesis that are avoided because it is associated with a risk of fetal loss, and the non-invasive procedures that use of fetal DNA circulating in maternal blood. We report a new Nested PCR method with specific primers for repetitive sequences of the Y-chromossome. Our results indicated that sensitivity and specificity of the method were 100% and we can accurately detect Y-chromossome sequences in samples with only 100 femtograms of DNA template.

Procalcitonina semicuantitativa (PCT-Q) como prueba diagnóstica y marcador pronóstico en niños con sepsis bacteriana / Semiquantitative procalcitonin (PCT-Q) as a diagnostic tool and prognostic marker in children with bacterial sepsis

Introducción. El presente trabajo evalúa la utilidad de la prueba para diagnóstico temprano de infección bacteriana, en pacientes con criterios de síndrome de respuesta inflamatoria sistémica (SRIS) por el método semicuantitativo (PCT-Q®), con otro grupo de pacientes que presenta SRIS sin infección bacteriana. Objetivo: probar el poder diagnóstico de este nuevo marcador PCT-Q® en pacientes con infecciones bacterianas en una fase temprana, además como marcador pronóstico y mortalidad. Material y métodos. Diseño: prueba diagnóstica. Se seleccionaron 2 grupos, uno con 22 pacientes con criterios de SRIS con infección bacteriana, demostrados con hemocultivos positivos (sepsis), y otro con 18 pacientes con criterios de SRIS sin infección bacteriana. Las variables estudiadas: PCT-Q® con punto de corte de > 10 ng/mL y mortalidad. Resultados. Primer día en el grupo de estudio resultaron positivos 18 casos y 2 casos en el grupo de control, con un valor de P =0.00063, altamente significativo. En la mortalidad, al séptimo día, se presentaron 8 casos en el grupo de estudio y 1 caso en el grupo control, con un valor de P =0.04, significativo. En la distribución de sexos, en el grupo de estudio se presentaron 15 casos del sexo masculino, y 5 casos en el grupo control, en el sexo femenino 7 casos en el grupo de estudio y 13 casos en el grupo control, con un valor de P =0.01104 altamente significativo, con un riesgo relativo de 2.1428. La sensibilidad y especificidad en este estudio fue 82 y 89%; VPP de 90% y VPN de 80%. índice de mortalidad de 44.4%. Conclusiones. La PCT-Q® es una herramienta útil en detectar pacientes con sepsis bacteriana en una fase temprana. Niveles persistentes > 10 ng/mL de PCT-Q® en pacientes con sepsis, ponen en correlación la gravedad de la enfermedad y muerte.

Introduction. This study evaluates the utility of the semiquantitative determination of procalcitonin (PCT-Q®) in the early diagnosis of bacterial infection in patients with systemic inflammatory response syndrome (SIRS) and positive bacterial cultures with another group of patients that presented SIRS without positive bacterial cultures. Objective: to evaluate PCT-Q® as a diagnostic tool of this new PCT-Q® marker in patients with bacterial infections in an early phase, besides and as prognostic marker in as prognosis and mortality Scoreboard. Material and methods. Design: comparative and transversal cross sectional study. Two groups were selected. The study group: included 22 patients with SIRS and positive blood cultures, shown with positive blood cultives (sepsis). The control group: included 18 patients with SIRS criteria but negative bacterial cultures. The male to female distribution in both groups included 15/22 in the study group vs 5/18 in the controls; P =0.01104. The studied variables: PCT-Q® with a cut off > 10 ng/mL and mortality. Results. On the first day, 18 cases in the study group and 2 cases in the control group, yielded a highly significant positive value; P =0.00063. By the 7th day, 8 deaths had occurred in the study group and only 1 in the control group; P =0.04. The mortality rate was of the 44.4% with a relative risk of 2.1428; the sensitivity and specificity in this study was 82 and 89% respectively. Conclusions. The PCT-Q® is a useful tool for the early detection of patients with bacterial sepsis. Persistent levels > 10 ng/mL of PCT-Q in patients with sepsis, correlates the severity of the illness and death.