Sistema de microencapsulação de urease com quitosana - PVA : reatividade e aplicações

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciencias Fisicas e MatematicasNeste trabalho foi investigada a microencapsulação da urease na forma de extrato bruto (EE), através do método de coacervação salina, utilizando-se o sistema polimérico quitosana-PVA. A quitosana foi obtida a partir da quitina, que por sua vez foi extraída da casca do camarão e o EE foi extraído das sementes da Cucurbita pepo (abóbora). Os parâmetros do processo de microencapsulação tais como composição e pH da blenda, temperatura e tempo de coagulação, foram ajustados afim de maximizar a atividade enzimática. Através da comparação do perfil de pH, dependência de temperatura e constante de Michaelis-Menten, demonstrou-se que o uso do EE é uma alternativa em relação à utilização da urease padrão (EP). A microscopia eletrônica de varredura comprovou a encapsulação da urease. As determinações das atividades enzimáticas mostraram que a alta concentração salina, utilizada no processo de microencapsulação, não afetou a atividade da enzima. Os ensaios estatísticos mostraram que a enzima se distribui homogeneamente nas cápsulas durante o processo de microencapsulação e que há reprodutibilidade na determinação da atividade enzimática do EE. A urease microencapsulada mostrou uma reusabilidade de 23 vezes e a estabilidade do EE no processo de estocagem foi maior quando comparada com a EP. Ensaios in vitro mostraram que a determinação do teor de uréia em amostras de sangue e urina, usando-se a urease microencapsulada, são coerentes com os resultados obtidos a partir das mesmas amostras, através do método espectrofotométrico, realizado no Laboratório de Análises Clínicas do Hospital Universitário da UFSC

Modelling Noise and Imprecision in Individual Decisions

When individuals take part in decision experiments, their answers are typically subject to some degree of noise / error / imprecision. There are different ways of modelling this stochastic element in the data, and the interpretation of the data can be altered radically, depending on the assumptions made about the stochastic specification. This paper presents the results of an experiment which gathered data of a kind that has until now been in short supply. These data strongly suggest that the 'usual' (Fechnerian) assumptions about errors are inappropriate for individual decision experiments. Moreover, they provide striking evidence that core preferences display systematic departures from transitivity which cannot be attributed to any 'error' story.Error Imprecision Preferences Transitivity

Cognitive performance and the thymus among HIV-infected subjects receiving HAART

Maria J Miguez-Burbano1, John E Lewis2, Jose Moreno3, Joel Fishman41Robert Stempel School of Public Health & School of Medicine, Florida International University, Miami, FL, USA; 2Department of Psychiatry and Behavioral Sciences, 3Department of Medicine, 4Department of Radiology, University of Miami Miller School of Medicine, Miami, FL, USAObjective: To evaluate the impact of alcohol use, which is widespread in human immunodeficiency virus (HIV)+ individuals, on highly active antiretroviral therapy (HAART)-associated immune and cognitive improvements and the relationship between those two responses.Methods: In a case-control longitudinal study, thymic volume, cognition, and immune responses were evaluated at baseline and after 6 months therapy in HIV+ and HIV- controls. Cognitive performance was evaluated using the HIV Dementia Score (HDS) and the California Verbal Learning Test (CVLT).Results: Prior to HAART, thymic volume varied considerably from 2.7 to 29.3 cm3 (11 ± 7.2 cm3). Thymic volume at baseline showed a significantly inverse correlation with the patient’s number of years of drinking (r2 = 0.207; p < 0.01), as well as HDS and the CVLT scores in both HIV-infected (r2 = 0.37, p = 0.03) and noninfected (r2 = 0.8, p = 0.01). HIV-infected individuals with a small thymic volume scored in the demented range, as compared with those with a larger thymus (7 ± 2.7 vs. 12 ± 2.3, p = 0.005). After HAART, light/moderate drinkers exhibited thymus size twice that of heavy drinkers (14.8 ± 10.4 vs. 6.9 ± 3.3 cm3).Conclusions: HAART-associated increases of thymus volume appear to be negatively affected by alcohol consumption and significantly related to their cognitive status. This result could have important clinical implications.Keywords: thymus, CNS, immune, alcoho

Are Serotonin Alterations the Link between Thrombocytopenia and Poor Immune Status among HIV Infected Individuals?

OBJECTIVE: Thrombocytopenia (TCP<150 × 10(3) cells/mm(3)) has emerged as a relevant factor in the clinical course of HIV. However, the mechanisms mediating such observations have not been well characterized, limiting the possibility of creating targeted interventions. Notably, platelets are the storage and transporter system for serotonin and Brain derived neurotrophic factor (BDNF), which recent laboratory studies associated with viral replication and lymphocyte survival. Thus, we posit that (1) TCP will be associated with reduced levels of BDNF and serotonin (2) That these alterations will lead to poor viro-immune responses to antiretroviral therapy. METHODS: To achieve this goal, a total of 400 people living with HIV were consecutively enrolled to characterize the frequency of thrombocytopenia in hazardous and non-hazardous alcohol user populations in the HAART era. Then, participants underwent immune and laboratory assessments, to determine if TCP was associated with alterations in serotonin (5-HT) and brain derived neurotrophic factor (BDNF). RESULTS: The prevalence of thrombocytopenia in this antiretroviral treated cohort was 14%. Rates were significantly higher in the heavy alcohol users, HAU versus the non HAU group (Heavy: 25% versus HAU: 15% versusnon-HAU: 10%). Multivariate model analyses indicated that having TCP, low BDNF levels (<5000 pg/ml), and number of drinks per day were predictors of serotonin levels. PLWH with TCP had about 2-fold lower PPP-BDNFlevels (5037.4 ± 381 vs. 9137.5 ± 7062 pg/ml p=0.0001). Other significant predictors of BDNF levels at the last visit included receiving selective serotonin reuptake inhibitors and PPP serotonin levels. Multivariate analyses also confirmed that altered serotonin levels were associated withhigh viral loadsboth low CD4 cell counts. CONCLUSIONS: Thrombocytopenia is a relatively frequent complication of HIV, andis particularly prevalent among hazardous alcohol users (HAU). These findings suggest that TCP is associated with altered levels of BDNF and serotonin, suggesting that they may be the bridge linking TCP and poor viro-immune responses observed in this group. These results could have important clinical and therapeutic implications

Alcohol, Brain Derived Neurotrophic Factor and Obesity among People Living with HIV

Introduction In an expanding HAART era, obesity has become a health problem among persons living with HIV (PLWH). Whereas the rising level of obesity has been largely attributed to poor nutrition and exercise habits, differences in biological factors may explain why some individuals gain more weight than others. Thus, our main goal is to prospectively determine in PLWH whether plasma brain-derived neurotrophic factor (BDNF), and hazardous alcohol use (HAU), two overlooked but highly prevalent conditions among PLWH, correlate with an adverse anthropometric profile. Also to test whether these relationships varied in men and women Methods The Platelets mediating Alcohol and HIV Damage Study (PADS) is an ongoing multiethnic study of 400 PLWH receiving regular medical care in South Florida (37% females and 63% males). Semi-annual visits consisted of a medical exam, including anthropometrics to assess both general (body mass index: BMI) and central obesity (waist and hip circumferences). Participants also completed health history questionnaires, and provided a fasting blood sample to obtain BDNF and immune and biochemical assessments. Results A sizable proportion of participants met the National Institutes of Health definition of overweight (BMI = 25?29.9 kg/m2; 26%) and obese (BMI ? 30 kg/m2; 35%). Women were more likely to be obese than men (OR=4.9, 95% CI=2.9?8.2, p=0.0001). Compared to men, women also exhibited the highest mean plasma BDNF levels (9,959 ± 6,578 vs. 7,470 ± 6,068 pg/ml, p=0.0001). Additional analyses indicated that HAU, particularly heavy drinkers, had the smallest waist and hip circumferences if they were males, but the opposite if they were females. High BDNF levels were positively correlated with BMI. Linear regression analysis revealed that gender, BDNF, and HAU were the best predictors of BMI. Conclusion In summary, our findings offer novel insights into the relationships between BDNF, and alcohol use among overweight and obese PLWH. Our results also suggest that these relationships may be inherently different by gender

Molecular dynamics and thermodynamical modelling using SAFT-VR to predict hydrate phase equilibria : application to CO2 hydrates

This work was dedicated to the prediction of the three phase coexistence line (CO2 hydrate–liquid H2Oliquid/vapour CO2) for the H2O+CO2 binary mixture by using (i) molecular dynamics simulations, and (ii) the well known van der Waals-Platteeuw (vdWP) model combined with the SAFT-VR equation of state. Molecular dynamics simulations have been performed using the simulation package GROMACS. The temperature at which the three phases are in equilibrium was determined for different pressures, by using direct coexistence simulations. Carbon dioxide was modelled as a linear-rigid chain molecule with three chemical units, the well-known version TraPPE molecular model. The TIP4P/Ice model was used for water. To perform the thermodynamical modelling, the SAFT-VR EOS was incorporated in the vdWP framework. The values of the cell model parameters were regressed and discussed together with the influence of some assumptions of the vdWP model. Since SAFT-VR can describe most of fluids involved in hydrate modelling (inhibitors, salts…), this study is a first step in the description of hydrate forming conditions of more complex systems. Finally, the three-phase coexistence temperatures obtained with both simulations and theory at different pressures were compared with experimental result

Aligned urns: study of a pre-hispanic funerary context from a sector of the Tucumán lowlands (Argentina)

Se presentan los análisis de un contexto funerario compuesto por cuatro vasijas dispuestas en línea procedente del sitio Anta Yacu 2, ubicado en la zona de Horco Molle (Departamento Yerba Buena, Tucumán). La estrategia metodológica consistió en la excavación y registro de los contenidos internos de las vasijas y el análisis de los materiales recuperados (cerámica, huesos humanos) con el objetivo de establecer las características principales de las prácticas funerarias en este sector del piedemonte tucumano. Los resultados sugieren que los restos óseos de cuatro individuos jóvenes fueron depositados de forma secundaria en dichas vasijas (toscas y sin decoración), las cuales habrían sido enterradas hacia el año 200 a.C. Por último, se revisan e integran otros casos análogos previamente reportados para el piedemonte tucumano-salteño y se postulan algunas implicancias sobre este tipo de inhumaciones.In this paper, we present the analysis of a funerary context composed of four urns arranged in line from the Anta Yacu 2 site, located in the area of ​​ Horco Molle (Department of Yerba Buena, Tucumán). The methodological strategy consisted in the excavation and registration of the internal contents of the urns and the analysis of the recovered materials (pottery, human bones), with the objective of establishing the main characteristics of funerary practices in this sector of the piedmont of Tucumán. The results suggest that these urns (rough and unrefined) contained the skeletal remains of four young individuals, which would have been buried around 200 BC as secondary inhumations. Finally, other similar cases previously reported for the Tucumán-Salta piedmont are reviewed and integrated, and some implications for this type of burials are discussed.Fil: Miguez, Gabriel Eduardo. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Arqueología y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Caria, Mario Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucumán. Instituto Superior de Estudios Sociales; ArgentinaFil: Muntaner, Ana Celina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucumán. Instituto Superior de Estudios Sociales; ArgentinaFil: González Baroni, Lucia Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucumán. Instituto Superior de Estudios Sociales; ArgentinaFil: Guerrero, Rita A.. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Barazzutti, Maria Jose. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Arqueología y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucumán. Instituto Superior de Estudios Sociales; Argentin

Long or complicated mpox in patients with uncontrolled HIV infection

To date, former research about the impact of HIV infection on mpox poor outcomes is still limited and controversial. Therefore, the aim of this study was to assess the impact of HIV on the clinical course of mpox, in a large population of patients from Spain. Nationwide case-series study. Patients from 18 Spanish hospitals, with PCR-confirmed mpox from April 27, 2022 to June 30, 2023 were included in this study. The main outcome was the development of long or complicated (LC) mpox, defined as: (i) duration of the clinical course ≥ 28 days, or; (ii) disseminated disease, or: (iii) emergence of severe complications. One thousand eight hundred twenty-three individuals were included. Seven hundred eighty-six (43%) were people living with HIV (PLWH), of whom 11 (1%) had a CD4 cell count < 200 cells/mm3 and 33 (3%) <350 cells/mm3 . HIV viral load ≥ 1000 cp/mL was found in 27 (3%) PLWH, none of them were on effective ART. Fifteen (60%) PLWH with HIV-RNA ≥ 1000 cp/mL showed LC versus 182 (29%) PLWH with plasma HIV-RNA load < 1000 copies/mL and 192 (24%) individuals without HIV infection (p < 0.001). In multivariate analysis, adjusted by age, sex, CD4 cell counts and HIV viral load at the time of mpox, only plasma HIV-RNA ≥ 1000 cp/mL was associated with a greater risk of developing LC mpox [adjusted OR = 4.06 (95% confidence interval 1.57-10.51), p = 0.004]. PLWH with uncontrolled HIV infection, due to lack of ART, are at a greater risk of developing LC mpox. Efforts should be made to ensure HIV testing is carried out in patients with mpox and to start ART without delay in those tested positive

Remdesivir in Very Old Patients (≥80 Years) Hospitalized with COVID-19: Real World Data from the SEMI-COVID-19 Registry

Background: Large cohort studies of patients with COVID-19 treated with remdesivir have reported improved clinical outcomes, but data on older patients are scarce. Objective: This work aims to assess the potential benefit of remdesivir in unvaccinated very old patients hospitalized with COVID-19; (2) Methods: This is a retrospective analysis of patients >= 80 years hospitalized in Spain between 15 July and 31 December 2020 (SEMI-COVID-19 Registry). Differences in 30-day all-cause mortality were adjusted using a multivariable regression analysis. (3) Results: Of the 4331 patients admitted, 1312 (30.3%) were >= 80 years. Very old patients treated with remdesivir (n: 140, 10.7%) had a lower mortality rate than those not treated with remdesivir (OR (95% CI): 0.45 (0.29-0.69)). After multivariable adjustment by age, sex, and variables associated with lower mortality (place of COVID-19 acquisition; degree of dependence; comorbidities; dementia; duration of symptoms; admission qSOFA; chest X-ray; D-dimer; and treatment with corticosteroids, tocilizumab, beta-lactams, macrolides, and high-flow nasal canula oxygen), the use of remdesivir remained associated with a lower 30-day all-cause mortality rate (adjusted OR (95% CI): 0.40 (0.22-0.61) (p < 0.001)). (4) Conclusions: Remdesivir may reduce mortality in very old patients hospitalized with COVID-19

Maria Jose Miguez: I-Corps: Diagnóstico de uso doméstico de flujo lateral para detección de COVID-19

Descripción de esta presentación: Esta presentación fue hecha por Maria Jose Miguez. El título de la presentación es: "I-Corps: Diagnóstico de uso doméstico de flujo lateral para detección de COVID-19." - Descripción de los seminarios web del CIC: Cada mes, el equipo del Centro de Información de COVID (junto con el Northeast Big Data Innovation Hub) reúne a un grupo de investigadores que estudian diversos aspectos de la pandemia actual, para compartir sus investigaciones y responder preguntas de nuestra comunidad. Los eventos muestran los esfuerzos continuos de los científicos en la lucha contra la COVID-19, incluyendo oportunidades de colaboración