Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
Eur J Cancer Prev ; 33(3): 243-251, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37997910

RESUMEN

Patient characteristics may influence access and acceptance of Prostate Specific Antigen test, and therefore, the timing of prostate cancer (PCa) diagnosis. A group of 361 patients from a cohort (n = 451) diagnosed with PCa in 2018-2020 at the Portuguese Institute of Oncology of Porto was evaluated before treatment, using a structured interview, the Medical Term Recognition Test, and the EORTC Quality of Life Questionnaire QLQ-PR25. PCa prognostic stages (I, II, III, IV) were attributed according to the American Joint Committee on Cancer eighth edition. Multinomial logistic regression was used to compute the odds ratio and 95% confidence interval (OR [95% CI]), considering PCa stage II, the most frequent, as reference. Older age (OR = 4.21 [2.24-7.93]), living outside the Porto Metropolitan Area while having low income (OR = 6.25 [1.53-25.62]), and erectile dysfunction (OR = 2.22 [0.99-4.99]) were associated with stage III, while urination during the night (OR = 3.02 [1.42-6.41]) was associated with stage IV. Urine leakage was less frequent in stage III (OR = 0.23 [0.08-0.68]), and living with a partner (OR = 0.41 [0.19-0.88]) and family history of cancer (OR = 0.25 [0.07-0.86]) in stage IV. Health literacy was not associated with PCa stage but lower education was less frequent in stage I (OR = 0.27 [0.11-0.69]). Patient sociodemographic and clinical characteristics should be considered as targets to improve PCa early detection and prognosis.


Asunto(s)
Alfabetización en Salud , Neoplasias de la Próstata , Masculino , Humanos , Pronóstico , Calidad de Vida , Conductas Relacionadas con la Salud
3.
J Clin Med ; 12(3)2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36769794

RESUMEN

Gingivitis and periodontitis are chronic inflammatory diseases that affect the supporting tissues of the teeth. Although induced by the presence of bacterial biofilms, other factor, such as tobacco smoking, drugs, and various systemic diseases, are known to influence their pathogenesis. Diabetes mellitus and periodontal diseases correspond to inflammatory diseases that have pathogenic mechanisms in common, with the involvement of pro-inflammatory mediators. A bidirectional relationship between type 2 diabetes and periodontitis has been documented in several studies. Significantly less studies have focused on the association between periodontal disease and type 1 diabetes. The aim of the study is to analyze the association between periodontal status and type 1 diabetes mellitus. The "Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines" was used and registered at PROSPERO. The search strategy included electronic databases from 2012 to 2021 and was performed by two independent reviewers. According to our results, we found one article about the risk of periodontal diseases in type 1 diabetes mellitus subjects; four about glycemic control; two about oral hygiene; and eight about pro-inflammatory cytokines. Most of the studies confirm the association between type 1 diabetes mellitus and periodontal diseases. The prevalence and severity of PD was higher in DM1 patients when compared to healthy subjects.

4.
Artículo en Inglés | MEDLINE | ID: mdl-35897487

RESUMEN

Prostate cancer (PCa) is the most prevalent among men, and psychological symptoms may affect many patients. This study aims to describe the prevalence of probable anxiety and depression before PCa treatments and after one year and to identify sociodemographic and clinical factors associated with these outcomes. Between February 2018 and March 2020, 292 patients recently diagnosed with PCa were recruited at the Instituto Português de Oncologia-Porto. The Hospital Anxiety and Depression Scale (HADS) was used to define probable anxiety and depression (cutoff = 11). The prevalence of probable anxiety remained stable from baseline to one year (7.8% vs. 8.5%, p = 0.866) while there was an increase in probable depression (3.1% vs. 6.8%, p = 0.012). After one year, probable depression persisted in 55.6% of patients with probable depression at baseline and 47.8% of those with probable anxiety at the first assessment had normal anxiety scores. At baseline, anxiety was more frequent among dwellers in rural areas (adjusted odds ratio-aOR, 95%CI: 2.80, 0.91-8.58) and less frequent in patients with body mass index 25-29.9 kg/m2 (aOR, 95%CI: 0.33, 0.12-0.91) compared to 18.5-24.9 Kg/m2, while those living alone had higher odds of depression (aOR, 95%CI: 6.35, 1.43-28.30). The frequency of anxiety and depression fluctuated during the course of treatment. Monitoring these symptoms would identify the most affected patients, contributing for a better use of mental health services.


Asunto(s)
Depresión , Neoplasias de la Próstata , Ansiedad/psicología , Trastornos de Ansiedad , Depresión/psicología , Estudios de Seguimiento , Humanos , Masculino , Prevalencia , Neoplasias de la Próstata/epidemiología , Neoplasias de la Próstata/psicología
5.
Cancers (Basel) ; 14(5)2022 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-35267663

RESUMEN

Cognitive impairment is common among patients with different types of cancer, even before cancer treatment, but no data were reported among patients with prostate cancer (PCa), who may be at high risk due to advanced age. This study aims to estimate the prevalence of cognitive impairment before PCa treatment. Between February 2018 and April 2021, the NEON-PC cohort recruited 605 patients with PCa proposed for treatment at the Portuguese Institute of Oncology of Porto. The Montreal Cognitive Assessment (MoCA) was used to assess cognitive performance. Participants with a MoCA < 1.5 standard deviations (SD) of age- and education-specific normative values were considered to have probable cognitive impairment (PCI) and were referred for a comprehensive neuropsychological assessment. Data from the population-based cohort EPIPorto (n = 351 men aged ≥40 years, evaluated in 2013−2015) were used for comparison. The prevalence of PCI was 17.4% in EPIPorto and 14.7% in NEON-PC (age- and education-adjusted odds ratio: 0.82, 95%CI: 0.58,1.18). Neuropsychological assessment was performed in 63 patients with PCa: 54.0% had cognitive impairment. These results suggest that the impact of PCa on cognitive performance could be negligible in the short term, contrary to what other studies have reported regarding other types of cancer.

6.
Med Eng Phys ; 100: 103757, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35144740

RESUMEN

This paper presents the optimization process for the development of an innovative double chamber syringe. Several aspects are involved such as design, functionality, fluid-structure interaction and friction between solids. To assist in the development of this medical device, a numerical based methodology was developed and validated in order to predict the syringe´s functionality, as well as its production by injection molding. The mechanical and flow behavior, during the filling and administration of medicine and washing solutions, were numerically modelled using the commercial software ABAQUS and FLUENT, respectively. The injection molding process was analyzed using the software MOLDFLOW. The aim was to evaluate the feasibility of the proposed concept in terms of mechanical design, fluid flow and production process behavior. By highlighting critical design issues in this way, it was possible to identify promising geometric changes and, consequently, optimize iteratively the syringe's design, until all the defined requirements are fulfilled. This iterative process based on numerical simulations proved to be a powerful tool for product development that generated fast and accurate results without the need to produce multiple prototypes.


Asunto(s)
Preparaciones Farmacéuticas , Jeringas , Cateterismo , Inyecciones
7.
Adv Ther ; 39(3): 1107-1125, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35025061

RESUMEN

Renal cell carcinoma (RCC) comprises a highly heterogeneous group of kidney tumours built upon distinct genetic- and epigenetic-driven mechanisms and molecular pathways. Therefore, responsiveness to treatment is considerably variable across patients, adding an extra layer of complexity to the already challenging therapeutic decision process. The last decade brought an unprecedented shift in the medical approach to advanced or metastatic RCC; in fact, immunotherapy-based combinations have significantly transformed the therapeutic arsenal and clinical outcomes of these patients. These strategies were quickly adopted by international guidelines committees as the new standards of care. However, this enhanced efficacy comes at the expense of tolerability, with a predictable negative impact on patients' quality of life. Moreover, subgroup and post hoc analyses of the major clinical trials have shown that not all patients benefit equally from these innovative approaches. In this context, a group of experts on kidney cancer met and discussed the state of the art in the field, with a special emphasis on the appropriateness of using monotherapy with an anti-angiogenesis tyrosine kinase inhibitor (TKI) to treat specific subgroups of patients with RCC. This article reviews the main topics that were considered to be pertinent for that discussion and establishes the profile of patients for whom TKI monotherapy remains a sensible frontline option by avoiding overtreatment and an unnecessary exposure to treatment-related toxicity.


Asunto(s)
Carcinoma de Células Renales , Neoplasias Renales , Carcinoma de Células Renales/tratamiento farmacológico , Carcinoma de Células Renales/patología , Humanos , Inmunoterapia , Neoplasias Renales/tratamiento farmacológico , Neoplasias Renales/patología , Inhibidores de Proteínas Quinasas/uso terapéutico , Calidad de Vida
8.
Pharmacogenomics ; 22(6): 365-373, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33749329

RESUMEN

Aim & methods: To review the existing literature concerning the relationship between venous thromboembolism (VTE) and prostate cancer (PC) and explore the putative biological and clinical implications of VTE genetic markers on PC patients by screening the PubMed database. Results: Considering the roles of VTE genome-wide association studies-identified genetic determinants in disease development in the general population, these variants might also underlie the susceptibility for PC-related VTE. Therefore, they could help to identify those with a positive benefit-to-harm ratio for thromboprophylaxis approaches during cancer therapy management, thereby improving patient's prognosis. Conclusion: Future studies are mandatory to explore the relationship between VTE and PC and dissect the predictive value of VTE genome-wide association studies-identified genetic determinants in PC patients, given their clinical implications.


Asunto(s)
Marcadores Genéticos , Neoplasias de la Próstata/genética , Tromboembolia Venosa/genética , Bases de Datos Genéticas , Estudio de Asociación del Genoma Completo , Humanos , Masculino , Pronóstico
9.
Mater Sci Eng C Mater Biol Appl ; 120: 111587, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33545809

RESUMEN

Representing a strategy of marine by-products valorization, based on isolation of biocompounds and assessment of biomedical applicability, the potential of blue shark (Prionace glauca (PG)) skin collagen to induce chondrogenic differentiation of human adipose stem cells (hASC) was investigated, with and without exogenous stimulation. For that, a cryogelation method was applied to produce highly interconnected porous 3-dimensional (3D) constructs made of collagen and collagen:hyaluronic acid (20:1). In vitro studies reveal that hASC adhere abundantly to the constructs which then suggests the early chondrogenic differentiation of those cells. These findings are supported by the mRNA expression encoding chondrogenic-related markers like Coll II and Sox-9 that are markedly upregulated at an early stage for both conditions, with and without exogenous stimulation. The introduction of hyaluronic acid (Hya) seems to play a crucial role at later time points, as shown by the evident immunodetection of aggrecan (ACAN), even without exogenous stimulation. It is hypothesized that the PG collagen itself can support chondrogenic differentiation at early time points, but exogenous stimulation is required to ensure phenotype maintenance. The present work highlights the relevance of using blue shark collagen biopolymer as a building block to produce highly effective temporary matrices for cartilage applications.


Asunto(s)
Cartílago , Tiburones , Animales , Diferenciación Celular , Células Cultivadas , Condrocitos , Condrogénesis , Colágeno , Humanos , Regeneración
10.
Artículo en Inglés | MEDLINE | ID: mdl-33187193

RESUMEN

Background: Flushing a venous access device is an important procedure to maintain their patency and prevent malfunctioning and complications. An innovative double-chamber syringe was developed, allowing for the assessment of catheter patency, drug delivery and final flush. This study aims to assess the usability of this new device, considering three development stages (concept, semi-functional prototype, functional prototype). Methods: An iterative methodology based on a mix-method design (qualitative and quantitative) enabled the assessment of the devices' usability by their primary end-users. A usability questionnaire was developed and applied, along with focus groups and individual interviews to nurses. Results: The usability questionnaire integrated 42 items focused on four dimensions (usefulness; ease of use; ease of learning; satisfaction and intention to use). The initial psychometric findings indicate a good internal consistency and the conceptual relevance of the items. The scores seem to be sensitive to the usability evaluation of the medical devices in different stages of product development (with lower values on functional prototype evaluation), and related to nurses' perceptions about functional and ergonomic characteristics. Conclusions: Quantitative and qualitative data provided a comprehensive overview of the double-chamber syringes' usability from the nurses' point of view, informing us of features that must be addressed.


Asunto(s)
Catéteres Venosos Centrales , Sistemas de Liberación de Medicamentos , Proyectos de Investigación , Interfaz Usuario-Computador , Catéteres Venosos Centrales/normas , Sistemas de Liberación de Medicamentos/métodos , Sistemas de Liberación de Medicamentos/normas , Femenino , Grupos Focales , Humanos , Masculino , Enfermeras y Enfermeros , Psicometría , Encuestas y Cuestionarios
11.
Pharmacogenomics ; 21(13): 919-928, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32787509

RESUMEN

Aim: To evaluate the influence of YB-1 rs10493112 variant as a genetic marker for response to second-generation androgen receptor axis-target agents. Methods: A hospital-based cohort study of 78 patients with metastatic castration-resistant prostate cancer was conducted. Genotyping was performed by TaqMan® allelic discrimination technology. Main results: In abiraterone-treated and high-risk patients, YB-1 rs10493112 AA genotype carriers showed lower progression-free survival than C allele genotype patients (4 vs 17 months; p = 0.009). For carriers of AA genotype, multivariate Cox regression analysis revealed a fivefold increased risk of progression (p = 0.035). Conclusion: The study findings suggest that, for metastatic and castration-resistant prostate cancer patients, this polymorphism might be a putative marker for the clinical outcome.


Asunto(s)
Resistencia a Antineoplásicos/genética , Neoplasias de la Próstata Resistentes a la Castración/genética , Receptores Androgénicos/genética , Proteína 1 de Unión a la Caja Y/genética , Anciano , Anciano de 80 o más Años , Androstenos/uso terapéutico , Antineoplásicos/uso terapéutico , Estudios de Cohortes , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico
12.
Acta Neurobiol Exp (Wars) ; 80(2): 129-138, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32602854

RESUMEN

Oxidative stress is now believed to play a crucial role for neurodevelopment disorders such as autism spectrum disorders (ASD) and attention deficit hyperactivity disorder (ADHD). To review the most recent literature regarding the role of oxidative stress for the pathophysiology of ASD and ADHD, we conducted a systematic search of the relevant literature and further discuss the clinical and research implications of this knowledge. A systematic search in PubMed database retrieved 132 articles, of which 33 were included in the review. This review found relevant evidence concerning the role of oxidative status in ASD and ADHD, albeit with some contradictory findings. In order to overcome the incongruities found, more studies are needed in the study of neurodevelopmental disorders, with more thorough study designs and particular attention to the accuracy of the diagnostic tools used for the cases included.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/complicaciones , Atención/fisiología , Trastorno del Espectro Autista/complicaciones , Estrés Oxidativo/fisiología , Conducta/fisiología , Psiquiatría Infantil/métodos , Humanos
13.
PLoS One ; 15(6): e0235087, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32584864

RESUMEN

BACKGROUND: In nursing practice, flushing the catheters pre and post-drug administration is considered an important clinical procedure to prevent complications, and requires the use of several syringes to comply with international standards of care. We envisioned an innovative double-chamber syringe that enables the filling and administration of both solutions. Following current international recommendations, the development of new medical devices should integrate Health Technology Assessment. The Human-centred design is usually used for that assessment purposes, as a method that actively include end-users in the devices development process. METHOD: Application of the Human-Centred Design through the involvement of nurses in the initial stages of the device development in order to accomplish the initial stages of Technology Readiness Level. A multi-method approach was used, including literature/guidelines review, focus groups with end-users and expert panels. RESULTS: The involvement of nurses enabled the definition of user requirements and contexts of use, as well as the evaluation of design solutions and prototypes in order to accomplish with usability and ergonomic features of the medical device. CONCLUSIONS: Significant contributions were made regarding the final design solution of this innovative double-chamber syringe.


Asunto(s)
Enfermeras y Enfermeros , Jeringas , Administración Intravenosa , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Preparaciones Farmacéuticas/administración & dosificación
14.
Artículo en Inglés | MEDLINE | ID: mdl-33561056

RESUMEN

A new double-chamber syringe (DUO Syringe) was developed for intravenous drug administration and catheter flushing. This study presents a protocol for pre-clinical usability tests to validate the golden prototype of this new device, performed in a high-fidelity simulation lab by nurses. A two-steps parallel randomized controlled trial with two arms was designed (with standard syringes currently used in clinical practice and with the DUO Syringe). After randomization, eligible and consented participants will be requested to perform, individually, intravenous drug administration and flushing, following the arm that has been allocated. The procedure will be video-recorded for posterior analyses. After the completion of the tasks, nurses will be asked to answer a demographic survey, as well as an interview about their qualitative assessment of the device. A final focus group with all participants will also be conducted. Primary outcomes will concern the DUO Syringe's effectiveness, efficiency, and safety, while secondary outcomes will focus on nurses' satisfaction and intention of use. The pre-clinical protocol was defined according to the legal requirements and ISO norms and was reviewed and approved by the Ethics Committee of the Health Sciences Research Unit: Nursing of the Nursing School of Coimbra.


Asunto(s)
Administración Intravenosa/instrumentación , Preparaciones Farmacéuticas/administración & dosificación , Ensayos Clínicos Controlados Aleatorios como Asunto , Jeringas/efectos adversos , Diseño de Equipo , Humanos , Resultado del Tratamiento
15.
ChemMedChem ; 14(14): 1325-1328, 2019 07 17.
Artículo en Inglés | MEDLINE | ID: mdl-31162877

RESUMEN

Quadruplex nucleic acids are promising targets for cancer therapy. In this study we used a fragment-based approach to create new flexible G-quadruplex (G4) DNA-interactive small molecules with good calculated oral drug-like properties, based on quinoline and triazole heterocycles. G4 melting temperature and polymerase chain reaction (PCR)-stop assays showed that two of these compounds are selective G4 ligands, as they were able to induce and stabilize G4s in a dose- and DNA sequence-dependent manner. Molecular docking studies have suggested plausible quadruplex binding to both the G-quartet and groove, with the quinoline module playing the major role. Compounds were screened for cytotoxicity against four cancer cell lines, where 4,4'-(4,4'-(1,3-phenylene)bis(1H-1,2,3-triazole-4,1-diyl))bis(1-methylquinolin-1-ium) (1 d) showed the greater activity. Importantly, dose-response curves show that 1 d is cytotoxic in the human colon cancer HT-29 cell line enriched in cancer stem-like cells, a subpopulation of cells implicated in chemoresistance. Overall, this study identified a new small molecule as a promising lead for the development of drugs targeting G4 in cancer stem cells.


Asunto(s)
Antineoplásicos/farmacología , ADN/metabolismo , G-Cuádruplex/efectos de los fármacos , Quinolinas/farmacología , Triazoles/farmacología , Animales , Antineoplásicos/síntesis química , Antineoplásicos/metabolismo , Sitios de Unión , Línea Celular Tumoral , ADN/genética , Diseño de Fármacos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Ratones , Simulación del Acoplamiento Molecular , Quinolinas/síntesis química , Quinolinas/metabolismo , Triazoles/síntesis química , Triazoles/metabolismo
16.
Planta ; 246(6): 1083-1096, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28801786

RESUMEN

MAIN CONCLUSION: The grapevine VvCAX3 mediates calcium transport in the vacuole and is mostly expressed in green grape berries and upregulated by Ca 2+ , Na + and methyl jasmonate. Calcium is an essential plant nutrient with important regulatory and structural roles in the berries of grapevine (Vitis vinifera L.). On the other hand, the proton-cation exchanger CAX proteins have been shown to impact Ca2+ homeostasis with important consequences for fruit integrity and resistance to biotic/abiotic stress. Here, the CAX gene found in transcriptomic databases as having one of the highest expressions in grapevine tissues, VvCAX3, was cloned and functionally characterized. Heterologous expression in yeast showed that a truncated version of VvCAX3 lacking its NNR autoinhibitory domain (sCAX3) restored the ability of the yeast strain to grow in 100-200 mM Ca2+, demonstrating a role in Ca2+ transport. The truncated VvCAX3 was further shown to be involved in the transport of Na+, Li+, Mn2+ and Cu2+ in yeast cells. Subcellular localization studies using fluorescently tagged proteins confirmed VvCAX3 as a tonoplast transporter. VvCAX3 is expressed in grapevine stems, leaves, roots, and berries, especially at pea size, decreasing gradually throughout development, in parallel with the pattern of calcium accumulation in the fruit. The transcript abundance of VvCAX3 was shown to be regulated by methyl jasmonate (MeJA), Ca2+, and Na+ in grape cell suspensions, and the VvCAX3 promotor contains several predicted cis-acting elements related to developmental and stress response processes. As a whole, the results obtained add new insights on the mechanisms involved in calcium homeostasis and intracellular compartmentation in grapevine, and indicate that VvCAX3 may be an interesting target towards the development of strategies for enhancement of grape berry properties.


Asunto(s)
Calcio/metabolismo , Proteínas de Transporte de Catión/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Transporte de Catión/genética , Cationes/metabolismo , Frutas/genética , Frutas/fisiología , Homeostasis , Hojas de la Planta/genética , Hojas de la Planta/fisiología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/genética , Raíces de Plantas/fisiología , Protones , Vacuolas/metabolismo , Vitis/genética , Vitis/fisiología
17.
Eur J Med Chem ; 135: 49-59, 2017 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-28431354

RESUMEN

A series of 9-mer and 13-mer amide-bridged cyclic peptides derived from the linear prototype Ac-PKIIQSVGIS-Nle-K-Nle-NH2 (Toro et al. ChemBioChem2013) has been designed and synthesized by introduction of the lactam between amino acid side chains that are separated by one helical turn (i, i+4). All of these compounds were tested in vitro as both dimerization and enzyme inhibitors of Leishmania infantum trypanothione reductase (Li-TryR). Three of the 13-mer cyclic peptide derivatives (3, 4 and 6) inhibited the oxidoreductase activity of Li-TryR in the low micromolar range and they also disrupted enzyme dimerization. Cyclic analogues 3 and 4 were more resistant to proteases than was the linear prototype. Furthermore, the most potent TryR inhibitors in the linear and cyclic series displayed potent in vitro activity against Leishmania infantum upon conjugation with cationic cell-penetrating peptides. To date, these conjugated peptides can be considered the first example of TryR dimerization inhibitors that are active in cell culture.


Asunto(s)
Antiprotozoarios/farmacología , Inhibidores Enzimáticos/farmacología , Leishmania infantum/efectos de los fármacos , NADH NADPH Oxidorreductasas/antagonistas & inhibidores , Péptidos/farmacología , Antiprotozoarios/síntesis química , Antiprotozoarios/química , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Dimerización , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Leishmania infantum/citología , Leishmania infantum/metabolismo , Simulación de Dinámica Molecular , Estructura Molecular , NADH NADPH Oxidorreductasas/metabolismo , Péptidos/síntesis química , Péptidos/química , Relación Estructura-Actividad
19.
Biotechnol J ; 2(3): 353-60, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17167766

RESUMEN

The surface of an acrylic fibre was modified with a commercial nitrilase (EC 3.5.5.1). The effect of fibre solvents and polyols on nitrilase catalysis efficiency and stability was investigated. The nitrilase action on the acrylic fabric was improved by the combined addition of 1 M sorbitol and 4% N, N-dimethylacetamide. The colour levels for samples treated with nitrilase increased 156% comparing to the control samples. When the additives were introduced in the treatment media, the colour levels increased 199%. The enzymatic conversion of nitrile groups into the corresponding carboxylic groups, on the fibre surface, was followed by the release of ammonia and polyacrylic acid. A surface erosion phenomenon took place and determined the "oscillatory" behaviour of the amount of dye uptake with time of treatment. These results showed that the outcome of the application of the nitrilase for the acrylic treatment is intimately dependent on reaction media parameters, such as time, enzyme activity and formulation.


Asunto(s)
Acrilatos/metabolismo , Aminohidrolasas/metabolismo , Nitrilos/metabolismo , Acetamidas/química , Acetamidas/farmacología , Acrilatos/química , Resinas Acrílicas/química , Resinas Acrílicas/metabolismo , Aminohidrolasas/química , Amoníaco/química , Amoníaco/metabolismo , Catálisis , Hidrólisis/efectos de los fármacos , Nitrilos/química , Sorbitol/química , Sorbitol/farmacología , Propiedades de Superficie , Textiles
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...