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1.
Braz. j. biol ; 84: e251970, 2024. tab, graf
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1345559

ABSTRACT

Abstract In order to better understand the ossification processes in anurans our study was carried out on tadpoles and adults of Lithobates catesbeianus. In this sense, we characterized the kinetic properties of alkaline phosphatase with p-nitrophenylphosphatase (pNPP) and pyrophosphate (PPi) and evaluated the activities of tartrate-resistant acid phosphatase and acid phosphatase. The enzyme extracts were obtained from tadpoles and adult femurs, which were divided into epiphysis and diaphysis. After homogenization, the samples were submitted to differential centrifugation to obtain cell membranes and, further, to phospholipase C (PIPLC) treatment, to remove membrane-bound proteins anchored by phosphatidylinositol. The average of specific activity for pNPP hydrolysis (at pH 10.5) by alkaline phosphatase released by phosphatidylinositol-specific phospholipase C (PIPLC) from Bacillus cereus among different bone regions at different animal ages was 1,142.57 U.mg-1, while for PPi hydrolysis (at pH 8.0), it was 1,433.82 U.mg-1. Among the compounds tested for enzymatic activity, the one that influenced the most was EDTA, with approximately 67% of inhibition for pNPPase activity and 77% for PPase activity. In the case of kinetic parameters, the enzyme showed a "Michaelian" behavior for pNPP and PPi hydrolysis. The Km value was around 0.6mM for pNPPase activity and ranged from 0.01 to 0.11mM for PPase activity, indicating that the enzyme has a higher affinity for this substrate. The study of pNPP and PPi hydrolysis by the enzyme revealed that the optimum pH of actuation for pNPP was 10.5, while for PPi, which is considered the true substrate of alkaline phosphatase, was 8.0, close to the physiological value. The results show that regardless of the ossification type that occurs, the same enzyme or isoenzymes act on the different bone regions and different life stages of anurans. The similarity of the results of studies with other vertebrates shows that anurans can be considered excellent animal models for the study of biological calcification.


Resumo Para melhor compreender o processo de ossificação em anuros, nosso estudo foi conduzido em girinos e adultos de Lithobates catesbeianus. Nesse sentido, as propriedades cinéticas da fosfatase alcalina com p-nitrofenilfosfato (pNPP) e pirofosfato (PPi) foram caracterizadas, e as atividades enzimáticas das fosfatases ácida e ácida tartarato resistente foram avaliadas. Os extratos enzimáticos foram obtidos de fêmur de girinos e adultos, divididos em epífise e diáfise. Após a homogeneização as amostras foram submetidas à centrifugação diferencial para obter membrana celular e, em seguida, ao tratamento com fosfolipase C (PIPLC), para remover as proteínas de membrana ancoradas por fosfatidilinositol. A média da atividade específica da fosfatase alcalina, liberada pela PIPLC de Bacillus cereus, para a hidrólise de pNPP (pH 10,5) nas diferentes regiões do fêmur e idades dos animais foi de 1.142,57 U.mg-1, enquanto para a hidrólise do PPi (pH 8,0) foi de 1.433,82 U.mg-1. Entre os compostos testados para a atividade enzimática, o de maior influência foi o EDTA, inibindo aproximadamente 67% e 77% das atividades de pNPPase e PPase, respectivamente. Quanto aos parâmetros cinéticos, a enzima apresentou comportamento Michaeliano para a hidrólise dos dois substratos. O valor de Km foi de 0,6 mM para a atividade de pNPPase e variou de 0,01 a 0,11 para a atividade de PPase, indicando uma maior afinidade por esse substrato. O estudo da hidrólise de pNPP e PPi revelou que o pH ótimo aparente de atuação foi de 10,5 para o pNPP e 8,0 para o PPi, próximo ao fisiológico, sendo que esse é considerado o substrato natural da fosfatase alcalina. Os resultados demonstram que, apesar do tipo de ossificação que ocorre, a mesma enzima ou isoenzimas, atuam nos diferentes locais do osso e estágios de vida dos anuros. A similaridade dos estudos com os realizados com outros vertebrados apontam que os anuros podem ser considerados excelentes modelos animais para o estudo da calcificação biológica.


Subject(s)
Animals , Osteogenesis , Alkaline Phosphatase/metabolism , Rana catesbeiana , Bone and Bones/metabolism , Kinetics
2.
Univ. salud ; 23(3): 255-262, sep.-dic. 2021. tab, graf
Article in Spanish | LILACS, COLNAL | ID: biblio-1341772

ABSTRACT

Resumen Introducción: El momento articular durante la marcha se ha relacionado con diferentes procesos clínicos en la población adulto mayor, en Colombia no se cuentan con reportes propios. Objetivo: Analizar el momento aductor de la cadera durante la marcha de adultos mayores asintomáticos. Materiales y métodos: Se evaluó a 110 participantes siguiendo las referencias del software VICON NEXUS 2.8.1 modelo Full Body, se utilizó 2 plataformas de fuerza y el volumen de captura estuvo delimitado por 8 cámaras opto eléctricas Bonita 10. Se incluyó variables antropométricas, sociodemográficas, espaciotemporales y cinéticas durante la fase de apoyo, resaltando los dos picos máximos del momento aductor. Resultados: Las cifras del Pico Momento Aductor 1 y 2 (PMA1 y PMA2) fueron de 0,76 y 0,70 Nm/Kg respectivamente, estos picos se relacionaron con masa, talla e índice de masa corporal. Se construyó así una referencia para el análisis de adultos mayores asintomáticos. Conclusiones: La gráfica del momento aductor de la cadera es similar a la descrita por otros investigadores, pero en menor magnitud que en la población sintomática de coxartrosis.


Abstract Introduction: Although joint moment during waking has been associated with different clinical processes in the elderly population, there is a lack of reports in Colombia. Objective: To analyze the hip adductor moment during gait in asymptomatic older adults. Materials and methods: 110 participants were assessed using the VICON NEXUS 2.8.1. Full Body model software. 2 force platforms were used and the capture volume was delimited through 8 Bonita-10 optoelectronic cameras. Anthropometric, sociodemographic, spatiotemporal, and kinetic variables were included during the support phase, highlighting the two maximum peaks of the adductor moment. Results: The figures for Adductor Moment Peaks 1 and 2 (AMP1 and AMP2) were 0.76 and 0.70 Nm/Kg, respectively, which were related to mass, height and body mass index. Thus, a reference for the analysis of asymptomatic older adults was developed. Conclusion: The hip adductor moment graph is similar to that described by other researchers, but to a lesser extent than the values seen in coxarthrosis symptomatic population.


Subject(s)
Aged , Gait , Kinetics , Hip
3.
Rev. bras. med. esporte ; 27(5): 498-503, July-Sept. 2021. tab, graf
Article in English | LILACS | ID: biblio-1288623

ABSTRACT

ABSTRACT Introduction: As skiers need to complete their movements in high mountains and snow, the athlete's landing's stability is directly related to the movement's success. The stable landing action wins high scores for the athletes' participating actions and protects their safety. Objective: This article analyzes the characteristics of lower limb muscle strength and static balance ability of female freestyle skiing aerials athletes to provide athletes with targeted strength training, evaluation of muscle effects after training, and athlete selection to provide a scientific basis valuable Theoretical reference. Methods: The paper uses isokinetic testing and balance testing methods to study the characteristics of the hip and knee flexor and extensor strengths of the Chinese great female freestyle skiing aerials athletes and the static balance characteristics in four standing positions. Results: The right flexor-extensor force, flexor-extensor force ratio, and average power value of the right hip joint were slightly greater than the left flexor power. The left and right knee joint extensor unit peak weight moments and the left and right average power values were all four indicators. Greater than the flexor, at different test speeds of 60°/s (slow speed) and 240°/s (fast), the peak flexion and extension torque per unit weight, the average power of flexion and extension, the force of flexion and extension, and the average power appear with the increase of the test speed as a significant difference. Conclusions: The research in the thesis recommends reasonable weight control and balanced training of muscle strength, using the condition of moderately increasing exercise speed, to strengthen the training of lower limb extensor strength, provide targeted strength training for athletes, evaluate the muscle effect after training and providing the scientific basis and valuable theoretical reference. Level of evidence II; Therapeutic studies - investigation of treatment results.


RESUMO Introdução: Como os esquiadores precisam completar seus movimentos em altas montanhas e neve, a estabilidade de pouso do atleta está diretamente relacionada ao sucesso do movimento. A ação de pouso constante ganha altas pontuações para os participantes e protege sua segurança. Objetivo: este artigo discute as características da força muscular das extremidades inferiores e habilidade de equilíbrio estático de atletas de esqui estilo livre para fornecer aos atletas treinamento de força específico e avaliação pós-treino dos efeitos musculares em atletas selecionados para fornecer uma base científica de referência teórica valiosa. Métodos: O artigo usa testes isocinéticos e métodos de teste de equilíbrio para estudar as características de força dos flexores e extensores de quadril e joelho de grandes atletas chinesas de esqui estilo livre e as características de equilíbrio estático em quatro posições de pé. Resultados: A força flexor-extensora direita, a relação da força flexor-extensora e o valor médio da potência da articulação do quadril direito foram ligeiramente maiores do que a potência do flexor esquerdo. Os momentos máximos de peso da unidade extensora da articulação do joelho esquerdo e direito e os valores médios das potências esquerda e direita foram os quatro indicadores. Maior que o flexor, em diferentes velocidades de teste de 60 ° / s (velocidade lenta) e 240 ° / s (rápido), o torque máximo de flexão e extensão por unidade de peso, a força média de flexão e extensão, a força de flexão e extensão, e a potência média aparece com o aumento da velocidade de teste como uma diferença significativa. Conclusões: A pesquisa na tese recomenda o controle de peso razoável e o treinamento de força muscular balanceado, utilizando a condição de aumentar moderadamente a velocidade do exercício, para fortalecer o treinamento de força extensora de membros inferiores, fornecer treinamento de força específico para atletas, avaliando o efeito muscular após formar e fornecer a base científica e um valioso referencial teórico. Nível de evidência II; Estudos terapêuticos- investigação dos resultados do tratamento.


RESUMEN Introducción: Como los esquiadores necesitan completar sus movimientos en alta montaña y nieve, la estabilidad del aterrizaje del atleta está directamente relacionada con el éxito del movimiento. La acción de aterrizaje estable gana puntuaciones altas para las participantes y protege su seguridad. Objetivo: Este artículo analiza las características de la fuerza muscular de las extremidades inferiores y la capacidad de equilibrio estático de las atletas de esquí de estilo libre para proporcionar a los atletas un entrenamiento de fuerza específico y una evaluación de los efectos musculares después del entrenamiento en atletas seleccionados para proporcionar una base científica de referencia teórica valiosa. Métodos: El artículo utiliza pruebas isocinéticas y métodos de prueba de equilibrio para estudiar las características de la fuerza de los flexores y extensores de cadera y rodilla de las grandes atletas chinas de esquí de estilo libre femenino y las características del equilibrio estático en cuatro posiciones de pie. Resultados: La fuerza flexora-extensora derecha, la relación de fuerza flexora-extensora y el valor de potencia promedio de la articulación de la cadera derecha fueron ligeramente mayores que la potencia del flexor izquierdo. Los momentos de peso máximo de la unidad extensora de la articulación de la rodilla izquierda y derecha y los valores de potencia promedio izquierda y derecha fueron los cuatro indicadores. Mayor que el flexor, a diferentes velocidades de prueba de 60 ° / s (velocidad lenta) y 240 ° / s (rápido), el par máximo de flexión y extensión por unidad de peso, la potencia promedio de flexión y extensión, la fuerza de flexión y extensión, y la potencia media aparecen con el aumento de la velocidad de prueba como una diferencia significativa. Conclusiones: La investigación en la tesis recomienda un control de peso razonable y un entrenamiento equilibrado de la fuerza muscular, utilizando la condición de aumentar moderadamente la velocidad del ejercicio, para fortalecer el entrenamiento de la fuerza extensora de las extremidades inferiores, proporcionar entrenamiento de fuerza específico para los atletas, evaluar el efecto muscular después del entrenamiento y proporcionar la base científica y una valiosa referencia teórica. Nivel de evidencia II; Estudios terapéuticos- investigación de los resultados del tratamiento.


Subject(s)
Humans , Female , Adult , Young Adult , Skiing/physiology , Postural Balance/physiology , Muscle Strength/physiology , Knee Joint/physiology , Algorithms , Kinetics , Models, Theoretical
4.
Electron. j. biotechnol ; 52: 45-51, July. 2021. ilus, tab, graf
Article in English | LILACS | ID: biblio-1283499

ABSTRACT

BACKGROUND: Acidithiobacillus ferrooxidans is a facultative anaerobe that depends on ferrous ion oxidation as well as reduced sulfur oxidation to obtain energy and is widely applied in metallurgy, environmental protection, and soil remediation. With the accumulation of experimental data, metabolic mechanisms, kinetic models, and several databases have been established. However, scattered data are not conducive to understanding A. ferrooxidans that necessitates updated information informed by systems biology. RESULTS: Here, we constructed a knowledgebase of iron metabolism of A. ferrooxidans (KIMAf) system by integrating public databases and reviewing the literature, including the database of bioleaching substrates (DBS), the database of bioleaching metallic ion-related proteins (MIRP), the A. ferrooxidans bioinformation database (Af-info), and the database for dynamics model of bioleaching (DDMB). The DBS and MIRP incorporate common bioleaching substrates and metal ion-related proteins. Af-info and DDMB integrate nucleotide, gene, protein, and kinetic model information. Statistical analysis was performed to elucidate the distribution of isolated A. ferrooxidans strains, evolutionary and metabolic advances, and the development of bioleaching models. CONCLUSIONS: This comprehensive system provides researchers with a platform of available iron metabolism-related resources of A. ferrooxidans and facilitates its application.


Subject(s)
Acidithiobacillus/metabolism , Iron/metabolism , Kinetics , Knowledge Bases
5.
Electron. j. biotechnol ; 50: 10-15, Mar. 2021. ilus, graf, tab
Article in English | LILACS | ID: biblio-1292308

ABSTRACT

BACKGROUND: LXYL-P1-2 is the first reported glycoside hydrolase that can catalyze the transformation of 7-b-xylosyl-10-deacetyltaxol (XDT) to 10-deacetyltaxol (DT) by removing the D-xylosyl group at the C7 position. Successful synthesis of paclitaxel by one-pot method combining the LXYL-P1-2 and 10- deacetylbaccatin III-10-b-O-acetyltransferase (DBAT) using XDT as a precursor, making LXYL-P1-2 a highly promising enzyme for the industrial production of paclitaxel. The aim of this study was to investigate the catalytic potential of LXYL-P1-2 stabilized on magnetic nanoparticles, the surface of which was modified by Ni2+-immobilized cross-linked Fe3O4@Histidine. RESULTS: The diameter of matrix was 20­40 nm. The Km value of the immobilized LXYL-P1-2 catalyzing XDT (0.145 mM) was lower than that of the free enzyme (0.452 mM), and the kcat/Km value of immobilized enzyme (12.952 mM s 1 ) was higher than the free form (8.622 mM s 1 ). The immobilized form maintained 50% of its original activity after 15 cycles of reuse. In addition, the stability of immobilized LXYL-P1-2, maintained 84.67% of its initial activity, improved in comparison with free form after 30 d storage at 4 C. CONCLUSIONS: This investigation not only provides an effective procedure for biocatalytic production of DT, but also gives an insight into the application of magnetic material immobilization technology.


Subject(s)
Paclitaxel/biosynthesis , Glycoside Hydrolases/metabolism , Kinetics , Enzymes, Immobilized , Nanoparticles , Magnets
6.
Rev. bras. med. esporte ; 27(1): 30-35, Jan.-Mar. 2021. tab, graf
Article in English | LILACS | ID: biblio-1156104

ABSTRACT

ABSTRACT Introduction Swimming starts are an important component for decreasing the total race time, especially in short events. In this phase of swimming, the aim is to increase performance using many different techniques and starting platforms. Objectives The effects of height and slope of the starting block on kick-start performance were assessed in this study. Methods Six male competitive swimmers performed 24 kick-starts using four block settings: 65 cm & 75 cm flat and 65 cm & 75 cm sloped. Two-dimensional kinetic and three-dimensional kinematic data were analyzed, including average and maximum horizontal/vertical forces and impulses; reaction times; movement and block times; and take-off vertical/horizontal velocities. Two-way within-subject design ANOVAs were implemented to test the effects of block height and slope on the kinetic and kinematic variables. Results Block slope was the main factor affecting most of the dependent variables. Shorter block and movement times, greater average and maximum vertical forces, vertical impulse, and maximum horizontal force were found for the sloped settings. An inverse relationship was found between block height and 0-5 m times. Conclusion Based on the results, blocks with height of 75 cm and slope of 10° provided better results in swimmers' performance in the block phase. Level of evidence II, Therapeutic Studies -Investigating the Results of Treatment


RESUMO Introdução As largadas de natação são um componente importante para reduzir o tempo total de competição, especialmente em eventos curtos. Nessa fase da natação, o objetivo é aumentar o desempenho usando várias técnicas e plataformas de largada distintas. Objetivos Neste estudo, foram avaliados os efeitos da altura e da inclinação da plataforma sobre desempenho da saída kick-start. Métodos Seis nadadores de competição do sexo masculino realizaram 24 largadas, usando quatro tipos de bloco de partida (65 cm e 75 cm de altura planos e 65 cm e 75 cm com inclinação). Foram analisados dados cinéticos bidimensionais e cinemáticos tridimensionais, incluindo forças e impulsos horizontais/verticais médios e máximos; tempos de reação, movimento e de bloco; e velocidades vertical/horizontal da decolagem. Empregou-se o método ANOVA bidirecional intraindivíduo para analisar os efeitos da altura e da inclinação do bloco sobre as variáveis cinéticas e cinemáticas. Resultados A inclinação do bloco foi o principal fator que afetou a maioria das variáveis dependentes. Nas plataformas de largada inclinadas, verificou-se que os tempos de bloco e movimento eram mais curtos e as forças verticais médias e máximas, o impulso vertical e a força horizontal máxima foram maiores nas configurações inclinadas. Foi encontrada uma relação inversa entre a altura do bloco e os tempos para as distâncias de 0 a 5 metros. Conclusões Com base nos resultados, os blocos com 75 cm de altura e 10 graus de inclinação forneceram melhores resultados de desempenho dos nadadores na fase de bloco. Nível de Evidência II - Investigação dos resultados do tratamento.


RESUMEN Introducción Las largadas de natación son un componente importante para reducir el tiempo total de competición, especialmente en eventos cortos. En esta fase de natación, el objetivo es aumentar el desempeño usando varias técnicas y plataformas de largada distintas. Objetivos En este estudio, fueron evaluados los efectos de la altura y de la inclinación de la plataforma sobre desempeño de la salida kick-start. Métodos Seis nadadores de competición del sexo masculino realizaron 24 largadas, usando cuatro tipos de bloque de partida (65 cm y 75 cm de altura planos y 65 cm y 75 cm con inclinación). Fueron analizados datos cinéticos bidimensionales y cinemáticos tridimensionales, incluyendo fuerzas e impulsos horizontales/verticales promedios y máximos; tiempo de reacción, movimiento y de bloque; y velocidades vertical/horizontal del despegue. Se empleó el método ANOVA bidireccional intraindividuo para analizar los efectos de la altura y de la inclinación del bloque sobre las variables cinéticas y cinemáticas. Resultados La inclinación del bloque fue el principal factor que afectó a la mayoría de las variables dependientes. En las plataformas de largada inclinadas, se verificó que los tiempos de bloque y movimiento eran más cortos y las fuerzas verticales promedio y máximas, el impulso vertical y la fuerza horizontal máxima fueron mayores en las configuraciones inclinadas. Fue encontrada una relación inversa entre la altura del bloque y los tiempos para las distancias de 0 a 5 metros. Conclusiones Con base en los resultados, los bloques con 75 cm de altura y 10 grados de inclinación proporcionaron mejores resultados de desempeño de los nadadores en la fase de bloque. Nivel de Evidencia II; Investigación de los resultados del tratamiento


Subject(s)
Humans , Male , Posture/physiology , Swimming/physiology , Athletic Performance/physiology , Kinetics
7.
Electron J Biotechnol ; 49: 56-63, Jan. 2021. tab, ilus, graf
Article in English | LILACS | ID: biblio-1291900

ABSTRACT

BACKGROUND: 2R,3R-butanediol dehydrogenase (R-BDH) and other BDHs contribute to metabolism of 3R/3S-Acetoin (3R/3S-AC) and 2,3-butanediol (2,3-BD), which are important bulk chemicals used in different industries. R-BDH is responsible for oxidizing the hydroxyl group at their (R) configuration. Bacillus species is a promising producer of 3R/3S-AC and 2,3-BD. In this study, R-bdh gene encoding R-BDH from Bacillus sp. DL01 was isolated, expressed and identified. RESULTS: R-BDH exerted reducing activities towards Diacetyl (DA) and 3R/3S-AC using NADH, and oxidizing activities towards 2R,3R-BD and Meso-BD using NAD+ , while no activity was detected with 2S,3S-BD. The R-BDH showed its activity at a wide range of temperature (25 C to 65 C) and pH (5.0­8.0). The R-BDH activity was increased significantly by Cd2+ when DA, 3R/3S-AC, and Meso-BD were used as substrates, while Fe2+ enhanced the activity remarkably at 2R,3R-BD oxidation. Kinetic parameters of the R-BDH from Bacillus sp. DL01 showed the lowest Km, the highest Vmax, and the highest Kcat towards the racemic 3R/3S-AC substrate, also displayed low Km towards 2R,3R-BD and Meso-BD when compared with other reported R-BDHs. CONCLUSIONS: The R-BDH from Bacillus sp. DL01 was characterized as a novel R-BDH with high enantioselectivity for R-configuration. It considered NAD+ and Zn2+ dependant enzyme, with a significant affinity towards 3R/3S-AC, 2R,3R-BD, and Meso-BD substrates. Thus, R-BDH is providing an approach to regulate the production of 3R/3S-AC or 2,3-BD from Bacillus sp. DL01.


Subject(s)
Bacillus subtilis/enzymology , Alcohol Oxidoreductases/isolation & purification , Alcohol Oxidoreductases/metabolism , Temperature , Kinetics , Hydrogen-Ion Concentration , Acetoin
8.
Chinese Journal of Biotechnology ; (12): 4215-4230, 2021.
Article in Chinese | WPRIM | ID: wpr-921500

ABSTRACT

Threonine aldolases catalyze the aldol condensation of aldehydes with glycine to furnish β-hydroxy-α-amino acid with two stereogenic centers in a single reaction. This is one of the most promising green methods for the synthesis of optically pure β-hydroxy-α-amino acid with high atomic economy and less negative environmental impact. Several threonine aldolases from different origins have been identified and characterized. The insufficient -carbon stereoselectivity and the challenges of balancing kinetic versus thermodynamic control to achieve the optimal optical purity and yield hampered the application of threonine aldolases. This review summarizes the recent advances in discovery, catalytic mechanism, high-throughput screening, molecular engineering and applications of threonine aldolases, with the aim to provide some insights for further research in this field.


Subject(s)
Amino Acids , Catalysis , Glycine , Glycine Hydroxymethyltransferase/metabolism , Kinetics , Substrate Specificity , Threonine
9.
Article in English | WPRIM | ID: wpr-921355

ABSTRACT

Objective@#The coronavirus disease 2019 (COVID-19) pandemic continues to present a major challenge to public health. Vaccine development requires an understanding of the kinetics of neutralizing antibody (NAb) responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).@*Methods@#In total, 605 serum samples from 125 COVID-19 patients (from January 1 to March 14, 2020) varying in age, sex, severity of symptoms, and presence of underlying diseases were collected, and antibody titers were measured using a micro-neutralization assay with wild-type SARS-CoV-2.@*Results@#NAbs were detectable approximately 10 days post-onset (dpo) of symptoms and peaked at approximately 20 dpo. The NAb levels were slightly higher in young males and severe cases, while no significant difference was observed for the other classifications. In follow-up cases, the NAb titer had increased or stabilized in 18 cases, whereas it had decreased in 26 cases, and in one case NAbs were undetectable at the end of our observation. Although a decreasing trend in NAb titer was observed in many cases, the NAb level was generally still protective.@*Conclusion@#We demonstrated that NAb levels vary among all categories of COVID-19 patients. Long-term studies are needed to determine the longevity and protective efficiency of NAbs induced by SARS-CoV-2.


Subject(s)
Adult , Aged , Aged, 80 and over , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , Female , Humans , Kinetics , Male , Middle Aged , Neutralization Tests , SARS-CoV-2
10.
Article in Chinese | WPRIM | ID: wpr-887992

ABSTRACT

This study aims to investigate metabolic activities of psoralidin in human liver microsomes( HLM) and intestinal microsomes( HIM),and to identify cytochrome P450 enzymes( CYPs) and UDP-glucuronosyl transferases( UGTs) involved in psoralidin metabolism as well as species differences in the in vitro metabolism of psoralen. First,after incubation serial of psoralidin solutions with nicotinamide adenine dinucleotide phosphate( NADPH) or uridine 5'-diphosphate-glucuronic acid( UDPGA)-supplemented HLM or HIM,two oxidic products( M1 and M2) and two conjugated glucuronides( G1 and G2) were produced in HLM-mediated incubation system,while only M1 and G1 were detected in HIM-supplemented system. The CLintfor M1 in HLM and HIM were 104. 3,and57. 6 μL·min~(-1)·mg~(-1),respectively,while those for G1 were 543. 3,and 75. 9 μL·min~(-1)·mg~(-1),respectively. Furthermore,reaction phenotyping was performed to identify the main contributors to psoralidin metabolism after incubation of psoralidin with NADPH-supplemented twelve CYP isozymes( or UDPGA-supplemented twelve UGT enzymes),respectively. The results showed that CYP1 A1( 39. 5 μL·min~(-1)·mg~(-1)),CYP2 C8( 88. 0 μL·min~(-1)·mg~(-1)),CYP2 C19( 166. 7 μL·min~(-1)·mg~(-1)),and CYP2 D6( 9. 1 μL·min~(-1)·mg~(-1)) were identified as the main CYP isoforms for M1,whereas CYP2 C19( 42. 0 μL·min~(-1)·mg~(-1)) participated more in producing M2. In addition,UGT1 A1( 1 184. 4 μL·min~(-1)·mg~(-1)),UGT1 A7( 922. 8 μL·min~(-1)·mg~(-1)),UGT1 A8( 133. 0 μL·min~(-1)·mg~(-1)),UGT1 A9( 348. 6 μL·min~(-1)·mg~(-1)) and UGT2 B7( 118. 7 μL·min~(-1)·mg~(-1)) played important roles in the generation of G1,while UGT1 A9( 111. 3 μL·min~(-1)·mg~(-1)) was regarded as the key UGT isozyme for G2. Moreover,different concentrations of psoralidin were incubated with monkey liver microsomes( MkLM),rat liver microsomes( RLM),mice liver microsomes( MLM),dog liver microsomes( DLM) and mini-pig liver microsomes( MpLM),respectively. The obtained CLintwere used to evaluate the species differences.Phase Ⅰ metabolism and glucuronidation of psoralidinby liver microsomes showed significant species differences. In general,psoralidin underwent efficient hepatic and intestinal metabolisms. CYP1 A1,CYP2 C8,CYP2 C19,CYP2 D6 and UGT1 A1,UGT1 A7,UGT1 A8,UGT1 A9,UGT2 B7 were identified as the main contributors responsible for phase Ⅰ metabolism and glucuronidation,respectively. Rat and mini-pig were considered as the appropriate model animals to investigate phase Ⅰ metabolism and glucuronidation,respectively.


Subject(s)
Animals , Benzofurans , Coumarins , Dogs , Glucuronides , Glucuronosyltransferase/metabolism , Kinetics , Mice , Microsomes, Liver/metabolism , Phenotype , Rats , Species Specificity , Swine , Swine, Miniature/metabolism
11.
Chinese Journal of Biotechnology ; (12): 2513-2521, 2021.
Article in Chinese | WPRIM | ID: wpr-887817

ABSTRACT

Human secreted phospholipase A2 GIIE (hGIIE) is involved in inflammation and lipid metabolism due to its ability of hydrolyzing phospholipids. To reveal the mechanism of substrate head-group selectivity, we analyzed the effect of mutation of hGIIE on its activity and selectivity. hGIIE structural analysis showed that E54 might be related to its substrate head-group selectivity. According to the sequence alignment, E54 was mutated to alanine, phenylalanine, and lysine. Mutated genes were cloned and expressed in Pichia pastoris X33, and the enzymes with mutations were purified with 90% purity by ion exchange and molecular size exclusion chromatography. The enzymatic activities were determined by isothermal microthermal titration method. The Km of mutant E54K towards 1,2-dihexyl phosphate glycerol decreased by 0.39-fold compared with that of wild type hGIIE (WT), and the Km of E54F towards 1,2-dihexanoyl-sn-glycero-3-phosphocholine increased by 1.93-fold than that of WT. The affinity of mutant proteins with phospholipid substrate was significantly changed, indicating that E54 plays an important role in the substrate head-group selectivity of hGIIE.


Subject(s)
Humans , Kinetics , Mutation , Phospholipases A2, Secretory , Phospholipids , Saccharomycetales , Substrate Specificity
12.
Chinese Journal of Biotechnology ; (12): 2435-2442, 2021.
Article in Chinese | WPRIM | ID: wpr-887809

ABSTRACT

The stability of virus-like particles (VLPs) is currently the main factor affecting the quality of foot-and-mouth disease VLPs vaccines. In order to further improve the quality of the VLPs vaccine of foot-and-mouth disease (FMD), three amino acid modification sites were designed and screened through kinetic analysis software, based on the three-dimensional structure of FMDV. The three mutant recombinant plasmids were successfully prepared by the point mutation kit, transformed into Escherichia coli strain BL21 and expressed in vitro. After purification by Ni ion chromatography column, SDS-PAGE proved that the three amino acid mutations did not affect the expression of the target protein. The results of the stability study of three FMD mutant VLPs obtained by in vitro assembly show that the introduction of internal hydrophobic side chain amino acids made the morphology of VLPs more uniform (N4017W), and their stability was significantly improved compared to the other two VLPs. The internal hydrophobic force of the capsid contributes to the formation of VLPs and helps to maintain the stability of the capsid, providing new experimental ideas for improving the quality of VLPs vaccines, and helping to promote the development of VLPs vaccines.


Subject(s)
Amino Acids , Animals , Capsid Proteins/genetics , Foot-and-Mouth Disease/prevention & control , Foot-and-Mouth Disease Virus/genetics , Kinetics , Vaccines, Virus-Like Particle/genetics , Viral Vaccines/genetics
13.
Article in English | WPRIM | ID: wpr-880681

ABSTRACT

OBJECTIVES@#To establish mouse bone marrow transplantation by pretreatment with chemotherapy, and to explore the dynamic changes of immune cells in the early stage of allogeneic transplantation in the spleen of mice.@*METHODS@#Mice were divided into 4 groups (80 mg/kg group, 100 mg/kg group, 120 mg/kg group, and 150 mg/kg group) according to the difference in dose of busulfan. The mice were treated with busulfan and cyclophosphamide combined chemotherapy, and the appropriate dosage was determined by evaluating the myeloablative effect and drug toxicity. According to the type of the genetic transplantation, the mice were also divided into 4 groups: An allogeneic transplantation group, a homogenic transplantation group, a chemotherapy alone group, and a normal control group. The mice were pretreated with busulfan and cyclophosphamide before bone marrow transplantation. In the allogeneic transplantation group, the suspension of splenocytes was prepared at the first day, the 3rd day, the 5th day, and the 8th day after transplantation for flow cytometry detection, and the dynamic changes of splenic immune cells were analyzed. The homogeneic transplantation group served as the concurrent control, the normal control group served as the control of basic value of spleen immune cells, and the chemotherapy alone group was used to evaluate the myeloablative effect.@*RESULTS@#1) The optimal dose of busulfan was 100 mg/kg. The combination of busulfan and cyclophosphamide can restore the hematopoiesis of transplanted mice, and the toxicity associated with pretreatment is small. 2) In the allogeneic transplantation group: The hematopoietic reconstitution and high donor chimerism rate were achieved after transplantation. In the early phase of bone marrow transplantation, the T lymphocytes were the main cell group, while the recovery of B lymphocytes was relatively delayed. The dendritic cells and natural killer cells from donors were the earliest cells to recover and achieve high chimerism rate compared with T cells and B cells. Most T cells were in the initial T cell state within 5 days after allogeneic transplantation. However, in the 5th day after transplantation, these cells were mainly in the effective memory phenotype. The reconstruction of donor-derived naive T cells was slow, but the reconstruction of donor-derived effective memory T cells and regulatory T cells was relatively fast. 3) In the homogeneic transplantation group: The mice could recover hematopoiesis and the recovery of B lymphocytes was delayed. 4) In the chemotherapy alone group: All mice died in 12-15 days after chemotherapy, and the peripheral blood routine showed pancytopenia before death.@*CONCLUSIONS@#Pretreatment with chemotherapy can successfully establish the mouse model of bone marrow transplantation. There are difference in the proportion of T cells, B cells, natural killer cells, dendritic cells, effector memory T cells, initial T cells, and regulatory T cells after transplantation, and the relationship between donor and recipient is also changed.


Subject(s)
Animals , Bone Marrow Cells , Bone Marrow Transplantation , Busulfan , Cell Proliferation , Kinetics , Mice , Mice, Inbred C57BL , Transplantation, Homologous
14.
Article in Chinese | WPRIM | ID: wpr-880171

ABSTRACT

OBJECTIVE@#To explore the kinetics of infiltrated T cell in murine acute graft-versus-host disease (aGVHD) target organs after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and its relationship with tissue pathological damage and aGVHD progress.@*METHODS@#Male C57BL/6 (H-2K@*RESULTS@#Compared with BMT group, the number of infiltrated T cells in aGVHD target organs including liver, lung and gut increased since day 7 in BMT+T group (P<0.05). On day 14, 28, 40 and 47 after transplantation, more infiltrated CD3@*CONCLUSION@#Pathological damage of aGVHD target organs is induced by CD3


Subject(s)
Animals , Bone Marrow Transplantation , Graft vs Host Disease , Kinetics , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , T-Lymphocytes , Transplantation, Homologous
15.
Article in Chinese | WPRIM | ID: wpr-879097

ABSTRACT

Based on the target occupancy mathematical model, the binding kinetic process of potential active ingredients of lowering uric acid in Chrysanthemum morifolium with xanthine oxidase(XOD) was evaluated. The potential active ingredients of lowering uric acid in Ch. morifolium were screened by UPLC-Q-Exactivems MS technology, reference substance identification and in vitro enzymatic kinetics experiments. The binding kinetic parameters of xanthine oxidase and potential inhibitor in Ch. morifolium were determined by surface plasma resonance(SPR). The verified mathematical model of the XOD target occupancy evaluated the kinetic binding process of inhibitors and xanthine oxidase in vivo. According to UPLC-Q-Exactive MS and reference substance identification, 39 potential uric acid-lowering active ingredients in Ch. morifolium extracts were identified and the inhibitory activities of 23 compounds were determined. Three potential xanthine oxidase inhibitors were screened, namely genistein, luteolin, and apigenin. whose IC_(50 )were 1.23, 1.47 and 1.59 μmol·L~(-1), respectively. And the binding rate constants(K_(on)) were 1.26×10~6, 5.23×10~5 and 6.36×10~5 mol·L~(-1)·s~(-1), respectively. The dissociation rate constants(K_(off)) were 10.93×10~(-2), 1.59×10~(-2), and 5.3×10~(-2 )s~(-1), respectively. After evaluation by different administration methods, the three selected compounds can perform rapid and sustained inhibition of xanthine oxidase in vivo under combined administration. This study comprehensively evaluated the target occupancy process of three effective components in different ways of administration in vivo by UPLC-MS, concentration-response method, SPR technology and xanthine oxidase target occupancy model, which would provide a new research idea and method for screening active ingredients in traditional Chinese medicine.


Subject(s)
Chromatography, Liquid , Chrysanthemum , Flavonoids , Kinetics , Pharmaceutical Preparations , Tandem Mass Spectrometry , Xanthine Oxidase/metabolism
16.
Article in Chinese | WPRIM | ID: wpr-878885

ABSTRACT

In this study, Fick's first law and partition equilibrium were used to represent the internal and external mass transfer processes of Salviae Miltiorrhizae Radix et Rhizoma at the macroscopic level, and a mass transfer model was established. The specific surface area was integrated into the mass transfer resistance, which effectively avoided the irregular shape of medicinal materials and expanded the application scope of the model. Meanwhile, the mass transfer model was further combined with the kinetic model of salvia-nolic acid degradation to establish the extraction kinetic models of salvianolic acid B, lithospermic acid and Danshensu. The model was applied to study the extraction process of Salviae Miltiorrhizae Radix et Rhizoma. According to the sensitivity analysis results, the relative error of the model prediction was within 5% near the maximum extraction rate(320 min), and the prediction performance of the model was good. According to the investigation results of different process parameters, stirring could significantly accelerate the mass transfer rate of salvianolic acid B, while the mass transfer resistance and degradation rate constant were not affected by solvent-to-solid ratio. The linear relationship between the reciprocal of temperature and the logarithm of mass transfer resistance was good(R~2=0.996), indicating that the temperature and mass transfer resistance conformed to Arrhenius formula. In addition, we also found that the concentration changes of lithospermic acid and Danshensu were weakly affected by mass transferwhen the extraction temperature was higher than 358 K. This study has provided the basis for the process optimization and quality control of traditional Chinese medicine extraction.


Subject(s)
Drugs, Chinese Herbal , Kinetics , Medicine, Chinese Traditional , Rhizome , Salvia miltiorrhiza
17.
J. bras. pneumol ; 47(5): e20210166, 2021. tab, graf
Article in Portuguese | LILACS | ID: biblio-1340148

ABSTRACT

RESUMO Objetivo O objetivo deste estudo foi avaliar a cinética diafragmática, a função respiratória e a dosagem sérica de leptina e citocinas inflamatórias (IL-6 e TNF-α) em três grupos clínicos: obeso, asmático e saudável. Métodos Estudo clínico-exploratório realizado com 73 jovens (12-24 anos, sendo 42,5% do sexo masculino) alocados em três grupos: obesidade (GO, n = 33), índice de massa corporal (IMC z-score) ≥ + 2 e asmáticos leves controlados (GA, n = 26), classificados pela GINA, e grupo controle saudável (GC, n = 14). Os participantes foram submetidos à ultrassonografia diafragmática, espirometria, pressão respiratória máxima, níveis séricos de leptina e níveis de IL-6 e TNF-α em hemocultura total. Resultados A espessura do diafragma foi maior no GO em comparação ao GA e GC (2,0 ± 0,4 vs 1,7 ± 0,5 e 1,6 ± 0,2, respectivamente, com p < 0,05). A ventilação voluntária máxima (VVM) foi significativamente menor no GO e GA em relação ao GC (82,8 ± 21,4 e 72,5 ± 21,2 vs 102,8 ± 27,3, respectivamente, com p < 0,05). O GO tem a maior taxa de leptina entre todos os grupos (com os outros dois grupos, p < 0,05). Os três grupos tinham níveis semelhantes de TNF-α e IL-6. Conclusão A hipertrofia muscular encontrada no diafragma de indivíduos obesos pode ser justificada pelo aumento do trabalho respiratório imposto pela condição crônica da doença. Esse aumento de espessura não ocorreu em asmáticos leves controlados. Os marcadores IL-6 e TNF-α não detectaram evidências de inflamação muscular, embora fosse esperado que a leptina estivesse alterada em indivíduos obesos. Pacientes obesos e asmáticos apresentaram menor resistência pulmonar do que os saudáveis.


ABSTRACT Objective The aim of this study was to assess the diaphragm kinetics, respiratory function, and serum dosage of leptin and inflammatory cytokines (IL-6 and TNF-α) in three clinical groups: obese, asthmatic, and healthy. Methods This is a clinical exploratory study performed on 73 youths (12-24 years of age, 42.5% male) allocated into three groups: obesity (OG, n=33), body mass index (BMIz-score) ≥ +2, asthmatic (AG, n=26) controlled mild asthmatics, classified by GINA, and Healthy Control Group (CG, n=14). The participants were subjected to diaphragmatic ultrasound, spirometry, maximal respiratory pressure, serum leptin levels, and IL-6 and TNF-α whole blood cell culture levels. Results Diaphragm thickness was higher in OG in comparison to AG and CG (2.0±0.4 vs 1.7±0.5 and 1.6±0.2, both with p<0.05). Maximal voluntary ventilation (MVV) was significantly lower in OG and AG in relation to the CG (82.8±21.4 and 72.5±21.2 vs 102.8±27.3, both with p<0.05). OG has the highest leptin rate among the groups (with the other two groups had p<0.05). All groups had similar TNF-α and IL-6 levels. Conclusion The muscular hypertrophy found in the diaphragm of the obese individuals can be justified by the increase in respiratory work imposed by the chronic condition of the disease. Such increase in thickness did not occur in controlled mild asthmatics. The IL-6 and TNF-α markers detected no evidence of muscle inflammation, even though leptin was expected to be altered in obese individuals. Both obese and asthmatic patients had lower pulmonary resistance than the healthy ones.


Subject(s)
Humans , Male , Female , Adolescent , Young Adult , Asthma , Diaphragm/diagnostic imaging , Kinetics , Tumor Necrosis Factor-alpha , Leptin , Obesity/complications
18.
Braz. arch. biol. technol ; 64: e21210130, 2021. tab, graf
Article in English | LILACS | ID: biblio-1278436

ABSTRACT

Abstract This research aims to compare the classical thin-layer models, stepwise fit regression method (SRG) and artificial neural networks (ANN) in the modelling of drying kinetics of shrimp shell and crab exoskeleton. Thus, drying curves were obtained using a convective dryer (3.0 m/s) at temperatures of 30.45 and 60oC. The results showed a decreasing tendency for the drying time as the temperature increased for both materials. Drying curves modelling of both materials showed fitted results with R 2 adj >0.998 and MRE<13.128% for some thin-layer models. On the other hand, by SRG a simple model could be obtained as a function of time and temperature, with the greatest accuracy being found in the modelling of experimental data of crab exoskeleton, with MRE<10.149%. Finally, the ANNs were employed successfully in the modelling of drying kinetics, showing high prediction quality with the trained recurrent ANN models.


Subject(s)
Crustacea , Animal Shells , Kinetics , Neural Networks, Computer , Models, Anatomic
19.
Braz. arch. biol. technol ; 64: e21200182, 2021. tab, graf
Article in English | LILACS | ID: biblio-1339318

ABSTRACT

Abstract Solvent extraction of red pigments from fermented solids is reported. The pigments were produced by solid-state fermentation of oil palm frond (OPF) biomass with the food-safe fungus Monascus purpureus FTC 5357. The effects of extraction solvent and other operational conditions (pH, temperature, agitation rate, contact time) on the recovery of pigments are discussed. The recovery was maximized using aqueous ethanol (60% ethanol by vol) as solvent at pH 6, 30 °C, with an extraction time of 16 h and an agitation rate of 180 rpm. A fermented solids dry mass of 1 g was used for each 160 mL of solvent during extraction. The kinetics of extraction were assessed by fitting the experimental data to different models. Peleg's model proved to be the best for describing solid-liquid extraction of the pigments under the above specified conditions. The highest extraction yield of red pigments under the above specified optimal conditions was 207(6.08 AU g(1 dry fermented solids.


Subject(s)
Monascus , Coloring Agents , Fermentation , Kinetics
20.
Medicina (B.Aires) ; 80(6): 599-605, dic. 2020. graf
Article in Spanish | LILACS | ID: biblio-1250281

ABSTRACT

Resumen La cinética de la procalcitonina es útil para reducir la duración de la antibioticoterapia en pacientes críticos, pero no se analizó su rol en infecciones por gérmenes multirresistentes. Se realizó un estudio observacional retrospectivo, analizando las curvas de procalcitonina de pacientes con neumonías asociadas a ventilación mecánica (NAVM) y bacteriemias asociadas a catéter (BAC) con rescate bacteriano durante el período 1/11/16 a 1/7/19. Se estudiaron 16 pacientes con infección por gérmenes sensibles (10 BAC y 6 NAVM) y 10 por gérmenes multirresistentes (10 BAC y 10 NAVM). Los pacientes con BAC generadas por gérmenes multirresistentes presentaron valores de procalcitonina mayores que los pacientes con BAC por gérmenes sensibles: (39 ± 30 μg/l vs. 10.7 ± 11 μg/l, p = 0.02). Los pacientes con NAVM generada por gérmenes sensibles y multirresistentes presentaron valores de procalcitonina similares. El descenso de procalcitonina a niveles 80% menores al valor máximo o menores a 0.5 μg/l (con tratamiento antibiótico efectivo) fue más veloz en pacientes con infección por gérmenes sensibles (5 ± 1.8 días vs. 7.2 ± 2.9 días, p = 0.03). En las infecciones por gérmenes multirresistentes, la respuesta inflamatoria medida por procalcitonina fue más intensa y prolongada, aun con un tratamiento antibiótico efectivo. Sin embargo, el descenso se produjo antes de que finalizaran los esquemas antibióticos convencionales. Por este motivo, se considera necesario estudiar la potencial utilidad de protocolos antibióticos guiados por procalcitonina en pacientes con infecciones por gérmenes multirresistentes para reducir la exposición a antibióticos.


Abstract Procalcitonin guidance stimulates a reduction in the duration of antibiotic treatment in critically ill patients with a presumed bacterial infection, but its role in infections caused by multidrug-resistant bacteria has not been sufficiently explored. In this retrospective observational study, we analyzed procalcitonin curves of 32 patients with culture-confirmed ventilation-associated pneumonia (VAP) and catheter-related bloodstream infections (CRBSI) occurred during the period 11/1/2016 to 7/1/2019. Sixteen infections were caused by multidrug-resistant bacteria (10 CRBSI and 6 VAP) and other 16 by sensitive bacteria (10 CRBSI and 6 VAP). CRBSI generated by multidrug-resistant bacteria elicited significantly higher procalcitonin levels than CRBSI infections caused by sensitive bacteria (39 ± 30 μg/l vs. 10.7 ± 11 μg/l, p = 0.02). Patients with VAP caused by sensitive and multidrug-resistant bacteria elicited similar procalcitonin levels. The time to a decrease in procalcitonin level to less than 80% of the peak value or less than 0.5 μg/l upon effective antibiotic treatment was 7.2 ± 2.9 days in multidrug-resistant bacteria vs. 5 ± 1.8 days in sensitive bacteria (p = 0.03). In multidrug-resistant bacteria, the inflammatory response measured by procalcitonin is stronger and longer, even with an effective antibiotic treatment. However, the decline occurs before the conventional antibiotic scheme is completed. The potential application of antibiotic protocols guided by procalcitonin to these groups of patients grants further studies aimed to reduce exposure to antibiotics in critical multidrug-resistant infections.


Subject(s)
Humans , Bacterial Infections/drug therapy , Procalcitonin , Kinetics , Intensive Care Units , Anti-Bacterial Agents/therapeutic use
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