RESUMO
Objective: We aimed to determine the reliability of using the Fibrosis-4 (FIB-4) index in COVID-19 patients without underlying liver illness. Method: We employed multivariate logistic regression to identify variables that exhibited statistically significant influence on the ultimate outcome. Multilayer perceptron analysis was employed to develop a prediction model for the FIB-4 index concerning ICU admission and intubation rates. However, the scarcity of cases rendered the assessment of the mortality rate unfeasible. We plotted ROC curves to analyze the predictive strength of the FIB-4 index across various age groups. Result: In univariate logistic regression, only the FIB-4 index and respiratory rate demonstrated statistical significance on all poor outcomes. The FIB-4 index for mortality prediction had an ROC and AUC of 0.863 (95% CI: 0.781-0.9444). It demonstrates predictive power across age groups, particularly for age ≥65 (AUC: 0.812, 95% CI: 0.6571-0.9673) and age <65 (AUC: 0.878, 95% CI: 0.8012-0.9558). Its sensitivity for intubation and ICU admission prediction is suboptimal. Conclusion: FIB-4 index had promising power in prediction of mortality rate in all age groups.
RESUMO
An amperometric biosensor for the determination of ethanol has been constructed. It comprises a multiwalled carbon nanotubes (MWNTs) conduit, a Nafion binder, and an alcohol dehydrogenase (ADH) function. The measurement of ethanol is based on the signal produced by beta-nicotinamide adenine dinucleotide (NADH), the product of the enzymatic reaction. The MWNTs are cylindrical with an outer diameter in the range 40-60 nm, an inner diameter in the range 2-5 nm, and a length of up to several micrometers. The homogeneity of the resulting nanobiocomposite film was characterized by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The performance of the MWNTs-Nafion-ADH nanobiocomposite modified glassy carbon electrode was examined using cyclic voltammetry and amperometry in presence of NADH and in the presence of ethanol. The electrocatalytic activity of MWNTs towards the oxidation of NADH has allowed an effective low-potential amperometric determination of ethanol. In the case of 6 mgmL(-1) ADH, the MWNTs-Nafion-ADH nanobiocomposite film displayed a sensitivity of 830 nAmM(-1), a linear range up to 0.1 mM, a detection limit of 3 microM, and a response time of about 4 s.
Assuntos
Álcool Desidrogenase/química , Técnicas Biossensoriais , Eletroquímica/métodos , Etanol/química , Polímeros de Fluorcarboneto/química , Nanotecnologia/métodos , Nanotubos de Carbono/química , Álcool Desidrogenase/metabolismo , Materiais Biocompatíveis , Catálise , Eletrodos , Microscopia Eletrônica de Varredura , Modelos Químicos , Oxigênio/química , Silício/químicaRESUMO
Clinical features of Peutz-Jeghers syndrome (PJS), an autosomal dominant disorder, include clusters of melanotic spots on the lips and limbs, polyposis of the gastrointestinal (GI) tract, and propensity to develop neoplasms of the GI tract, ovaries, testes, and other sites. We report twin sisters with PJS who were found to be homozygous, based on analyses of 9 DNA markers containing short tandem repeats (STR). Aberrant expression of a putative tumor suppressor gene, STK11, which encodes a serine threonine kinase, has been suggested as the etiologic factor in PJS. In both of the twin sisters with PJS, mRNA analyses by RT-PCR demonstrated a complete lack of STK11 gene expression. These results provide direct evidence that STK11 gene expression is abnormal in PJS. Detecting abnormal expression of the STK11 gene may serve as a molecular approach to the diagnosis of PJS and may facilitate genotype-phenotype correlations in PJS patients.
Assuntos
Doenças em Gêmeos/genética , Síndrome de Peutz-Jeghers/genética , Proteínas Serina-Treonina Quinases/genética , Quinases Proteína-Quinases Ativadas por AMP , Adulto , Doenças em Gêmeos/diagnóstico , Doenças em Gêmeos/enzimologia , Feminino , Expressão Gênica , Marcadores Genéticos , Homozigoto , Humanos , Perda de Heterozigosidade , Síndrome de Peutz-Jeghers/diagnóstico , Síndrome de Peutz-Jeghers/enzimologia , Proteínas Serina-Treonina Quinases/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Gêmeos Monozigóticos/genéticaRESUMO
Novel electroanalytical sensing nanobiocomposite materials are reported. These materials are prepared by mixing multiwalled carbon nanotubes (MWNTs), a Nafion cation exchanger, and glucose oxidase (GOD) in appropriate amounts. The MWNTs are cylindrical with a diameter in the range 40-60 nm and with a length of up to several micrometers, and they provide electrical conductivity. Nafion acts as a polymer backbone to give stable and homogeneous cast thin films. Both MWNTs and Nafion provide negative functionalities to bind to positively charged redox enzymes such as glucose oxidase. The resulting biosensing composite material is inexpensive, reliable, and easy to use. The homogeneity of the MWNT-Nafion-GOD nanobiocomposite films was characterized by atomic force microscopy (AFM). Amperometric transducers fabricated with these materials were characterized electrochemically using cyclic voltammetry and amperometry in the presence of hydrogen peroxide and in the presence of glucose. Their linear response to hydrogen peroxide was demonstrated. The glucose biosensor sensitivity was strongly influenced by the glucose oxidase concentration within the nanobiocomposite film. The optimized glucose biosensor (2.5 mg/mL GOD) displayed a sensitivity of 330 nA/mM, a linear range of up to 2 mM, a detection limit of 4 microM, and a response time of <3 s.