Comparison of antibody response to SARS-CoV-2 after two doses of inactivated virus and BNT162b2 mRNA vaccines in kidney transplant.

BACKGROUND: Antibody response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) after mRNA or adenoviral vector-based vaccines is weak in kidney transplant (KT) patients. However, few studies have focused on humoral response after inactivated virus-based vaccines in KT. Here, we compare antibody response following vaccination with inactivated virus (CoronaVac®) and BNT162b2 mRNA. METHODS: A national multicentre cross-sectional study was conducted. The study group was composed of patients from all KT centres in Uruguay, vaccinated between 1 and 31 May 2021 (CoronaVac®, n = 245 and BNT162b2, n = 39). The control group was constituted of 82 healthy individuals. Participants had no prior confirmed coronavirus disease 2019 (COVID-19) test. Blood samples were collected between 30 and 40 days after the second dose. Serum-specific immunoglobulin G (IgG) antibodies against the receptor-binding domain (RBD) of SARS-CoV-2 Spike protein were determined using the COVID-19 IgG QUANT ELISA Kit. RESULTS: Only 29% of KT recipients showed seroconversion (36.5% BNT162b2, 27.8% inactivated virus, P = 0.248) in comparison with 100% in healthy control with either vaccine. Antibody levels against RBD were higher with BNT162b mRNA than with inactivated virus [median (interquartile range) 173 (73-554) and 29 (11-70) binding antibody units (BAU)/mL, P < 0.034] in KT and 10 times lower than healthy control [inactivated virus: 308 (209-335) and BNT162b2: 2638 (2608-3808) BAU/mL, P < 0.034]. In multivariate analysis, variables associated with negative humoral response were age, triple immunosuppression, estimated glomerular filtration rate and time post-KT. CONCLUSION: Seroconversion was low in KT patients after vaccination with both platforms. Antibody levels against SARS-CoV-2 were lower with inactivated virus than BNT162b mRNA. These findings support the need for strategies to improve immunogenicity in KT recipients after two doses of either vaccine.

Comparison of artificial neural networks an support vector machines for feature selection in electrogastrography signal processing.

The paper describes a feature selection process applied to electrogastrogram (EGG) processing. The data set is formed by 42 EGG records from functional dyspeptic (FD) patients and 22 from healthy controls. A wrapper configuration classifier was implemented to discriminate between both classes. The aim of this work is to compare artificial neural networks (ANN) and support vector machines (SVM) when acting as fitness functions of a genetic algorithm (GA) that performs a feature selection process over some features extracted from the EGG signals. These features correspond to those that literature shows to be the most used in EGG analysis. The results show that the SVM classifier is faster, requires less memory and reached the same performance (86% of exactitude) than the ANN classifier when acting as the fitness function for the GA.

Validez y confiabilidad de la versión chilena del Alcohol Use Disorders Identification Test (AUDIT) / Assessment of the alcohol use disorders identification test (AUDIT) to detect problem drinkers

Background: AUDIT is a self-reported questionnaire used to detect problem drinkers. It must be translated into Spanish and validated in order to be used in Chile. Aim: To assess the validity of a Chilean version of the AUDIT questionnaire. Material and methods: The English version of the questionnaire was translated into Spanish and adapted to the Chilean cultural environment. Using the Delphi method, an expert group examined the text and then decided on which would be the definitive version. This test was translated to English again and was approved by one of the original authors. It was then applied to 93 subjects aged 37 ± 12 years (60 percent males) consulting at a primary health care center These subjects also answered the Composite International Diagnostic Interview (CIDI), version 2.1 that was used as the gold standard for the diagnosis of hazardous drinking and alcohol dependence. Cronbach alpha and test-retest validity were analyzed. Sensitivity and specificity were determined using receiver operating (ROC) curves. Results: The internal consistency of AUDIT was 0.93, its test re-tests reliability was 0.97 (95 percent confidence intervals 0.96-0.98). Using a cutoff point of 6 for hazardous consumption, its sensitivity and specificity were 83 percent and 88 percent, respectively. The figures for dependence and harmful consumption, using a cutoff point of 9, were 87 percent and 85 percent, respectively. Conclusions: AUDIT is a valid questionnaire to detect problem drinkers.

The Alcohol Use Disorders Identification Test (AUDIT) as a screening instrument for adolescents.

BACKGROUND: The Alcohol Use Disorders Identification Test (AUDIT) is an international screening instrument extensively employed in adult target groups. However, there is scarce information on screening with the AUDIT in adolescent populations. The purpose of this study was to determine the cut-off point for hazardous, harmful, and dependent alcohol use through the validation of the AUDIT in a Chilean adolescent sample. METHODS: The original English version of the AUDIT was translated into Spanish, using the procedure recommended by the World Health Organization. The text was then back-translated and sent to one of the original authors (Thomas Babor), who approved the translation. Students attending public schools in Santiago, Chile, self-administered the AUDIT, and those older than 15 years completed the Composite International Diagnostic Interview-Substance Abuse Module (CIDI-SAM), which served as a gold standard. Between 1 and 4 weeks after the CIDI-SAM, participants answered a second AUDIT. RESULTS: A total of 42 female and 53 male adolescents (mean age: 15.9 [SD=1.2]) completed the AUDIT, with a mean score of 4.3. Reliability according to Cronbach's alpha was 0.83. Test-retest correlation was also satisfactory (intra-class correlation 0.81 [95% CI 0.73-0.87]). Analysis of the receiver operating characteristic (ROC) curve yielded cut-off points for hazardous, harmful, and dependent alcohol use of 3, 5, and 7 points, respectively. CONCLUSIONS: The Chilean version of the AUDIT is a valid and reliable tool for identifying adolescents with hazardous, harmful, and dependent alcohol use. The suggested cut-off points make screening with the AUDIT more accurate for adolescent populations.

[Assessment of the alcohol use disorders identification test (AUDIT) to detect problem drinkers]. / Validez y confiabilidad de la versión chilena del Alcohol Use Disorders Identification Test (AUDIT).

BACKGROUND: AUDIT is a self-reported questionnaire used to detect problem drinkers. It must be translated into Spanish and validated in order to be used in Chile. AIM: To assess the validity of a Chilean version of the AUDIT questionnaire. MATERIAL AND METHODS: The English version of the questionnaire was translated into Spanish and adapted to the Chilean cultural environment. Using the Delphi method, an expert group examined the text and then decided on which would be the definitive version. This test was translated to English again and was approved by one of the original authors. It was then applied to 93 subjects aged 37 +/- 12 years (60% males) consulting at a primary health care center These subjects also answered the Composite International Diagnostic Interview (CIDI), version 2.1 that was used as the gold standard for the diagnosis of hazardous drinking and alcohol dependence. Cronbach alpha and test-retest validity were analyzed. Sensitivity and specificity were determined using receiver operating (ROC) curves. RESULTS: The internal consistency of AUDIT was 0.93, its test re-tests reliability was 0.97 (95% confidence intervals 0.96-0.98). Using a cutoff point of 6 for hazardous consumption, its sensitivity and specificity were 83% and 88%, respectively. The figures for dependence and harmful consumption, using a cutoff point of 9, were 87% and 85%, respectively. CONCLUSIONS: AUDIT is a valid questionnaire to detect problem drinkers.