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1.
Biol Chem ; 402(4): 513-524, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33938181

RESUMO

Increasing antibiotic resistance in Gram-negative bacteria has mandated the development of both novel antibiotics and alternative therapeutic strategies. Evidence of interplay between several gastrointestinal peptides and the gut microbiota led us to investigate potential and broad-spectrum roles for the incretin hormone, human glucose-dependent insulinotropic polypeptide (GIP) against the Enterobacteriaceae bacteria, Escherichia coli and Erwinia amylovora. GIP had a potent disruptive action on drug efflux pumps of the multidrug resistant bacteria E. coli TG1 and E. amylovora 1189 strains. The effect was comparable to bacterial mutants lacking the inner and outer membrane efflux pump factor proteins AcrB and TolC. While GIP was devoid of direct antimicrobial activity, it has a potent membrane depolarizing effect, and at low concentrations, it significantly potentiated the activity of eight antibiotics and bile salt by reducing MICs by 4-8-fold in E. coli TG1 and 4-20-fold in E. amylovora 1189. GIP can thus be regarded as an antimicrobial adjuvant with potential for augmenting the available antibiotic arsenal.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Enterobacteriaceae/efeitos dos fármacos , Erwinia amylovora/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Peptídeos Semelhantes ao Glucagon/farmacologia , Antibacterianos/química , Peptídeos Semelhantes ao Glucagon/química , Humanos , Testes de Sensibilidade Microbiana
2.
Br J Surg ; 107(9): 1171-1182, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32259295

RESUMO

BACKGROUND: Whether patients who undergo resection of ampullary adenocarcinoma have a survival benefit from adjuvant chemotherapy is currently unknown. The aim of this study was to compare survival between patients with and without adjuvant chemotherapy after resection of ampullary adenocarcinoma in a propensity score-matched analysis. METHODS: An international multicentre cohort study was conducted, including patients who underwent pancreatoduodenectomy for ampullary adenocarcinoma between 2006 and 2017, in 13 centres in six countries. Propensity scores were used to match patients who received adjuvant chemotherapy with those who did not, in the entire cohort and in two subgroups (pancreatobiliary/mixed and intestinal subtypes). Survival was assessed using the Kaplan-Meier method and Cox regression analyses. RESULTS: Overall, 1163 patients underwent pancreatoduodenectomy for ampullary adenocarcinoma. After excluding 187 patients, median survival in the remaining 976 patients was 67 (95 per cent c.i. 56 to 78) months. A total of 520 patients (53·3 per cent) received adjuvant chemotherapy. In a propensity score-matched cohort (194 patients in each group), survival was better among patients who received adjuvant chemotherapy than in those who did not (median survival not reached versus 60 months respectively; P = 0·051). A survival benefit was seen in patients with the pancreatobiliary/mixed subtype; median survival was not reached in patients receiving adjuvant chemotherapy and 32 months in the group without chemotherapy (P = 0·020). Patients with the intestinal subtype did not show any survival benefit from adjuvant chemotherapy. CONCLUSION: Patients with resected ampullary adenocarcinoma may benefit from gemcitabine-based adjuvant chemotherapy, but this effect may be reserved for those with the pancreatobiliary and/or mixed subtype.


ANTECEDENTES: Actualmente se desconoce si la quimioterapia adyuvante ofrece un beneficio en la supervivencia de los pacientes que se someten a resección de un adenocarcinoma ampular. El objetivo de este estudio fue comparar la supervivencia mediante la concordancia estimada por emparejamiento por puntaje de propensión, entre pacientes con y sin quimioterapia adyuvante después de la resección de un adenocarcinoma ampular. MÉTODOS: Se realizó un estudio internacional de cohortes multicéntrico, que incluyó a los pacientes que se sometieron a una duodenopancreatectomía por adenocarcinoma ampular (2006-2017) en 13 centros de seis países. Los puntajes de propensión se usaron para emparejar a los pacientes que recibieron quimioterapia adyuvante con los que no; tanto en la cohorte completa como en dos subgrupos (subtipo pancreaticobiliar / mixto e intestinal). La supervivencia se evaluó utilizando el método de Kaplan-Meier y las regresiones de Cox. RESULTADOS: En total, 1.163 pacientes fueron sometidos a una duodenopancreatectomía por adenocarcinoma ampular. Después de excluir a 179 pacientes, la mediana de supervivencia de los 976 pacientes restantes fue de 67 meses (i.c. del 95%, 56-78), de los cuales un total de 520 pacientes (53%) recibieron quimioterapia adyuvante. En una cohorte de emparejamiento por puntaje de propensión (194 versus 194 pacientes), la mediana de supervivencia fue mejor en los pacientes tratados con quimioterapia adyuvante en comparación con aquellos sin quimioterapia adyuvante (no se alcanzó la mediana de supervivencia versus 60 meses, respectivamente; P = 0,051). En el subtipo pancreaticobiliar/mixto se observó un beneficio en la supervivencia; no se alcanzó la mediana de supervivencia en pacientes que recibieron quimioterapia adyuvante versus 32 meses en el grupo sin quimioterapia, P = 0,020. El subtipo intestinal no mostró beneficio en la supervivencia de la quimioterapia adyuvante. CONCLUSIÓN: Los pacientes con adenocarcinoma ampular resecado pueden beneficiarse de la quimioterapia adyuvante basada en gemcitabina, pero este efecto podría reservarse para aquellos pacientes con subtipo de tumor pancreaticobiliar y/o mixto.


Assuntos
Adenocarcinoma/tratamento farmacológico , Ampola Hepatopancreática , Antimetabólitos Antineoplásicos/uso terapêutico , Quimioterapia Adjuvante/métodos , Neoplasias do Ducto Colédoco/tratamento farmacológico , Desoxicitidina/análogos & derivados , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Idoso , Ampola Hepatopancreática/patologia , Ampola Hepatopancreática/cirurgia , Quimioterapia Adjuvante/mortalidade , Neoplasias do Ducto Colédoco/patologia , Neoplasias do Ducto Colédoco/cirurgia , Desoxicitidina/uso terapêutico , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Pancreaticoduodenectomia , Pontuação de Propensão , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Análise de Sobrevida , Gencitabina
3.
Dis Esophagus ; 30(11): 1-8, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28881905

RESUMO

The treatment of esophageal perforation (EP) remains a significant clinical challenge. While a number of investigators have previously documented efficient approaches, these were mostly single-center experiences reported prior to the introduction of newer technologies: specifically endoluminal stents. This study was designed to document contemporary practice in the diagnosis and management of EP at multiple institutions around the world and includes early clinical outcomes. A five-year (2009-2013) multicenter retrospective review of management and outcomes for patients with thoracic or abdominal esophageal perforation was conducted. Demographics, etiology, diagnostic modalities, treatments, subsequent early outcomes as well as morbidity and mortality were captured and analyzed. During the study period, 199 patients from 10 centers in the United States, Canada, and Europe were identified. Mechanisms of perforation included Boerhaave syndrome (60, 30.1%), iatrogenic injury (65, 32.6%), and penetrating trauma (25, 12.6%). Perforation was isolated to the thoracic segment alone in 124 (62.3%), with 62 (31.2%) involving the thoracoabdominal esophagus. Mean perforation length was 2.5 cm. Observation was selected as initial management in 65 (32.7%), with only two failures. Direct operative intervention was initial management in 65 patients (32.6%), while 29 (14.6%) underwent esophageal stent coverage. Compared to operative intervention, esophageal stent patients were significantly more likely to be older (61.3 vs. 48.3 years old, P < 0.001) and have sustained iatrogenic mechanisms of esophageal perforation (48.3% vs.15.4%). Secondary intervention requirement for patients with perforation was 33.7% overall (66). Complications included sepsis (56, 28.1%), pneumonia (34, 17.1%) and multi-organ failure (23, 11.6%). Overall mortality was 15.1% (30). In contemporary practice, diagnostic and management approaches to esophageal perforation vary widely. Despite the introduction of endoluminal strategies, it continues to carry a high risk of mortality, morbidity, and need for secondary intervention. A concerted multi-institutional, prospectively collected database is ideal for further investigation.


Assuntos
Perfuração Esofágica/cirurgia , Esofagoscopia/métodos , Adulto , Idoso , Canadá , Perfuração Esofágica/etiologia , Esofagoscopia/efeitos adversos , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Reoperação/estatística & dados numéricos , Estudos Retrospectivos , Stents , Resultado do Tratamento , Estados Unidos
4.
Gulf J Oncolog ; 1(45): 91-93, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38774937

RESUMO

Polycythemia vera (PV) is a chronic myeloproliferative disorder characterized by uncontrolled red blood cell production. Megaloblastic anemia is caused by deficiency of cobalamin (vitamin B12) and/or folate (vitamin B9). While B12 deficiency may be caused by insufficient dietary intake or impairment of its utilization, its association with PV is described without exact knowledge of the physiopathology. We herein report the occurrence of megaloblastic anemia due to Vitamin B12 deficiency in an 85-year-old North African woman patient with PV. This case highlights this atypical presentation of PV and challenges that comes with it causing the delay of diagnosis and the complexity of its diagnosis and treatment. Keywords: megaloblastic anemia, polycythemia vera, association, case report.


Assuntos
Anemia Megaloblástica , Policitemia Vera , Humanos , Feminino , Policitemia Vera/complicações , Policitemia Vera/diagnóstico , Idoso de 80 Anos ou mais , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/diagnóstico
5.
Infect Drug Resist ; 17: 2289-2298, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38860227

RESUMO

Introduction: Candida is the primary cause of invasive fungal disease, candidiasis, especially in developed nations. The increasing resistance observed in multiple antibiotics, coupled with the prolonged process of creating new antibiotics from the ground up, emphasizes the urgent requirement for innovative methods and new compounds to combat Candida infections. Employing a treatment strategy that combines antibiotics can improve efficacy, broaden the spectrum of targeted fungal, and reduce the chances of resistance emergence. This approach shows potential in tackling the escalating problem of antibiotic resistance. The objective of this research is to explore the potential synergistic effects of combining 3-hydrazinoquinoxaline-2-thiol and thymoquinone against a variety of Candida isolates. This investigation aims to offer an understanding of the collective antimicrobial action of these compounds. Methods: Broth microdilution was utilized to assess the Minimum Inhibitory Concentrations (MICs) of 3-hydrazinoquinoxaline-2-thiol and thymoquinone for 22 clinical Candida isolates. Following this, a checkerboard assay was employed to analyze the interaction between 3-hydrazinoquinoxaline-2-thiol and thymoquinone, with a specific focus on the Fractional Inhibitory Concentration Index (FICI). Results: The MICs of thymoquinone and 3-hydrazinoquinoxaline-2-thiol were determined for 22 clinical Candida strains, with thymoquinone exhibiting MICs ranging from 64 to 8 µg/mL, and 3-hydrazinoquinoxaline-2-thiol displaying MICs varying from 64 to 8 µg/mL. Notably, the combination of 3-hydrazinoquinoxaline-2-thiol and thymoquinone resulted in a synergistic effect, leading to a significant reduction in MICs, with reductions of up to 64-fold with FICI below 0.5 against tested strains. Conclusion: The prospect of using 3-hydrazinoquinoxaline-2-thiol in combination with thymoquinone as an effective solution against Candida looks encouraging. Nevertheless, to validate its practical applicability, additional comprehensive testing and experiments are imperative.

6.
ACS Omega ; 9(2): 2204-2219, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38250414

RESUMO

Mycobacterium tuberculosis is responsible for tuberculosis (TB) all over the world. Despite tremendous advancements in biomedical research, new treatment approaches, and preventive measures, TB incidence rates continue to ascend. The herbaceous plant Acalypha indica, also known as Indian Nettle, belongs to the Euphorbiaceae family and is known as one of the most important sources of medicines and pharmaceuticals for the medical therapy for a range of ailments. However, the precise molecular mechanism of its therapeutic action is still unknown. In this study, an integrated network pharmacology approach was employed to explore the potential mechanism of A. indica phytochemicals against TB. The active chemical components of A. indica were collected from two independent databases and published sources, whereas SwissTargetPrediction was used to identify the target genes of these phytochemicals. GeneCards and DisGeNET databases were employed to retrieve tuberculosis-related genes and variants. Following the evaluation of overlapped genes, gene enrichment analysis and PPI network analysis were performed using the DAVID and STRING databases, respectively. Later, to identify the potential target(s) for the disease, molecular docking was performed. A. indica revealed 9 active components with 259 potential therapeutic targets; TB attributed 694 intersecting genes from the two data sets; and both TB and A. indica overlapped 44 potential targets. The in-depth analysis based on the degree revealed that AKT1 and EGFR formed the foundation of the PPI network. Moreover, docking analysis followed by molecular dynamics simulations revealed that phytosterol and stigmasterol have higher binding affinities to AKT1 and EGFR to suppress tuberculosis. This study provides a convincing proof that A. indica can be exploited to target TB after experimental endorsement; further, it lays the framework for more experimental research on A. indica's anti-TB activity.

7.
Chem Commun (Camb) ; 59(86): 12899-12902, 2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37819671

RESUMO

Reactions between imines and tungsten alkylidyne complexes are studied. The trianionic pincer ligand supported alkylidyne [tBuOCO]WCC(CH3)3(THF)2 (1) reacts with N-(R)-1-phenylmethanimine (PMI-R, R = Me, Ph, Bn, and TMS) yielding [tBuOC(H)O]W(η2-tBuCCPh)N(R) (4-R), products from metathesis reaction. In contrast, the non-pincer alkylidyne (tBuO)3WCC(CH3)3 does not react with PMI-R imines.

8.
ACS Sens ; 8(2): 712-720, 2023 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-36749605

RESUMO

Common symptoms of food intolerance are caused by chemical components within food that have a pharmacological activity to alter the motility of the gastrointestinal tract. Food intolerance is difficult to diagnose as it requires a long-term process of eliminating foods that are responsible for gastrointestinal symptoms. Enterochromaffin (EC) cells are key intestinal epithelium cells that respond to luminal chemical stimulants by releasing 5-HT. Changes in 5-HT levels have been shown to directly alter the motility of the intestinal tract. Therefore, a rapid approach for monitoring the impact of chemicals in food components on 5-HT levels can provide a personalized insight into food intolerance and help stratify diets. Within this study, we developed a three-dimensional (3D)-printed electrochemical multiwell plate to determine changes in 5-HT levels from intestinal organoids that were exposed to varying chemical components found in food. The carbon black/poly-lactic acid (CB/PLA) electrodes had a linear range in physiological concentrations of 5-HT (0.1-2 µM) with a limit of detection of 0.07 µM. The electrodes were stable for monitoring 5-HT overflow from intestinal organoids. Using the electrochemical multiwell plate containing intestinal organoids, increases in 5-HT were observed in the presence of 0.1 mM cinnamaldehyde and 10 mM quercetin but reduction in 5-HT levels was observed in 1 mM sorbitol when compared to control. These changes in the presence of chemicals commonly found in food were verified with ex vivo ileum tissue measurements using chromatography and amperometry with boron-doped diamond electrodes. Overall, our 3D electrochemical multiwell plate measurements with intestinal organoids highlight an approach that can be a high-throughput platform technology for rapid screening of food intolerance to provide personalized nutritional diet.


Assuntos
Intolerância Alimentar , Serotonina , Humanos , Serotonina/análise , Íleo/química , Mucosa Intestinal/química , Organoides/química
9.
Sci Rep ; 10(1): 13625, 2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32788616

RESUMO

In the current work, a new generalized model of heat conduction has been constructed taking into account the influence of the microscopic structure into the on non-simple thermoelastic materials. The new model was established on the basis of the system of equations that includes three-phase lags of higher-order and two different temperatures, namely thermodynamic and conductive temperature. The two-temperature thermoelastic model presented by Chen and Gurtin (Z Angew Math Phys 19(4):614-627, 1968) and some other previous models have been introduced as special cases from the proposed model. As an application of the new model, we studied the thermoelastic interactions resulting from sudden heating in an isotropic solid subjected to external body force. The influence of the discrepancy parameter and higher-order of the time-derivative has been discussed. This work will enable future investigators to gain insight into non-simple thermoelasticity with different phase delays of higher-order in detail.

10.
Biosens Bioelectron ; 155: 112094, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32090867

RESUMO

A robust amperometric sensor was developed for the lactate detection in the extracellular matrix of cancer cells. The sensor was fabricated by separately immobilizing nicotinamide adenine dinucleotide (NAD+) onto a carboxylic acid group and lactate dehydrogenase (LDH) onto an amine group of bi-functionalized conducting polymer (poly 3-(((2,2':5',2″-terthiophen)-3'-yl)-5-aminobenzoic acid (pTTABA)) composited with N, S-doped porous carbon. Morphological features of the composite layer and sensor performance were investigated using FE-SEM, XPS, and electrochemical methods. The experimental parameters were optimized to get the best results. The calibration plot showed a linear dynamic range between 0.5 µM and 4.0 mM with the detection limit of 112 ± 0.02 nM. The proposed sensor was applied to detect lactate in a non-cancerous (Vero) and two cancer (MCF-7 and HeLa) cell lines. Among these cell lines, MCF-7 was mostly affected by the administration of lactate transport inhibitor, α-cyano-4-hydroxycinnamate (αCHC), followed by HeLa and Vero, respectively. Furthermore, the effect of αCHC concentration and treatment time on the lactate level in the cell lines were demonstrated. Finally, cytotoxicity studies were also performed to evaluate the effect of αCHC on cell viability.


Assuntos
Técnicas Biossensoriais/métodos , Ácido Láctico/análise , Nanotecnologia/métodos , Polímeros , Animais , Técnicas Biossensoriais/normas , Carbono , Linhagem Celular Tumoral , Ácidos Cumáricos/antagonistas & inibidores , Técnicas Eletroquímicas , Enzimas Imobilizadas , Humanos , L-Lactato Desidrogenase , Sondas Moleculares , Nanotecnologia/normas , Reprodutibilidade dos Testes
11.
J Physiol Pharmacol ; 70(6)2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32203939

RESUMO

Sitagliptin (SIT) is an antidiabetic used worldwide to ameliorate the hyperglycemia and insulin insensitivity induced dysmetabolism. In this study, we investigated the effect of sitagliptin and vitamin E on metabolic dysfunction in high-fat diet (HFD) fed rats. Sixty-four male rats were allocated into 8 groups (n = 8) as follow; control, control + vitamin E, control + sitagliptin, control + sitagliptin + vitamin E, HFD, HFD + vitamin E, HFD + sitagliptin and HFD + sitagliptin + vitamin E. Control groups were fed with chow diet for 15 weeks, while HFD groups were fed with HFD for the same duration. Vitamin E and sitagliptin were administered in the last 4 weeks of the study. At the end of the 15th week, body weight, liver weight/body weight ratio, weight gain, glucose, lipid profile, liver enzymes, adiponectin and pro-inflammatory cytokines as interleukin 6 (IL-6), high sensitive C reactive protein (hs-CRP) and tumour necrosis factor-α (TNF-α) were measured. Additionally, gene expressions of senescence marker protein 30 (SMP30), Bcl-2, and Bax were measured. Total antioxidant capacity (TAC) and thiobaribituric acid reactive substances (TBARS) were assayed. HFD increased TBARS, IL-6, hs-CRP and TNF-α significantly and decreased TAC and adiponectin. Sitagliptin produced a comparable result through increasing adiponectin, sitagliptin alone or in combination with vitamin E increased the TAC, and gene expression of SMP30 and Bcl-2 and decreased TBARS with downregulation of the overexpressed Bax. Vitamin E, as a natural antioxidant, ameliorates the oxidative stress with insignificant change in lipid profile and inflammatory cytokine levels. Concomitant sitagliptin and vitamin E reduced the hepatic dysfunction induced by HFD.


Assuntos
Adiponectina/metabolismo , Inflamação/tratamento farmacológico , Fosfato de Sitagliptina/farmacologia , Vitamina E/farmacologia , Animais , Antioxidantes/administração & dosagem , Antioxidantes/farmacologia , Biomarcadores/metabolismo , Citocinas/metabolismo , Dieta Hiperlipídica , Modelos Animais de Doenças , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/farmacologia , Inflamação/patologia , Mediadores da Inflamação/metabolismo , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Fosfato de Sitagliptina/administração & dosagem , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Vitamina E/administração & dosagem
12.
Biosens Bioelectron ; 130: 48-54, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30731345

RESUMO

Enzymatic and non-enzymatic amperometric glucose sensors based on nanostructured Au-Ni alloy were prepared and compared in their performance. The hierarchically structured Au-Ni surface was merely used for the non-enzymatic glucose sensor, while glucose oxidase attached poly-3'(benzoic acid) -2,2':5',2'- terthiophene (pTBA) formed on the alloy surface was used as the enzymatic sensor. The fabricated sensor was characterized using surface analysis and electrochemical experiments. In case of the enzymatic sensor, the anodic current of H2O2 generated from the enzyme reaction was used as the analytical signal, while the direct oxidation of glucose was observed on a mere Au-Ni alloy electrode without enzyme immobilization, which shows an excellent catalytic oxidation of glucose even in physiological pH. The potential pulse pretreatment of the sensor surfaces improved the performance, which allowed both the sensors reproducible and reusable (enzymatic sensor: coefficient of variation = 1.82%, n = 5, non-enzymatic: coefficient of variation = 2.93%). The enzymatic biosensor reveals the advantages of increased sensitivity, selectivity, and stability, compared with the non-enzymatic sensor. The linear range of enzymatic sensor was attained from 1.0 µM to 30.0 mM with a detection limit of 0.29 µM. The reliabilities of the sensors were also demonstrated through the glucose analysis in human blood samples, and the result was compared with the commercially available glucometer.


Assuntos
Técnicas Biossensoriais , Glicemia/isolamento & purificação , Técnicas Eletroquímicas , Nanoestruturas/química , Ligas/química , Glicemia/química , Catálise , Glucose Oxidase/química , Ouro/química , Humanos , Limite de Detecção , Níquel/química , Polímeros/química
13.
Biosens Bioelectron ; 109: 263-271, 2018 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-29571163

RESUMO

The analytical performance of the multi enzymes loaded single electrode sensor (SES) and dual electrode sensor (DES) was compared for the detection of adenosine and metabolites. The SES was fabricated by covalent binding of tri-enzymes, adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), and xanthine oxidase (XO) along with hydrazine (Hyd) onto a functionalized conducting polymer [2,2:5,2-terthiophene-3-(p-benzoic acid)] (pTTBA). The enzyme reaction electrode in DES was fabricated by covalent binding of ADA and PNP onto pTTBA coated on Au nanoparticles. The detection electrode in DES was constructed by covalent binding of XO and Hyd onto pTTBA coated on porous Au. Due to the higher amount (3.5 folds) of the immobilized enzymes and Hyd onto the DES than SES, and the lower Michaelis constant (Km) value for DES (28.7 µM) compared to SES (36.1 µM), the sensitivity was significantly enhanced for the DES (8.2 folds). The dynamic range obtained using DES was from 0.5 nM to 120.0 µM with a detection limit of 1.43 nM ±â€¯0.02, 0.76 nM ±â€¯0.02, and 0.48 nM ±â€¯0.01, for adenosine (AD), inosine (IN), and hypoxanthine (Hypo) respectively. Further, the DES was coupled with an electrochemical potential modulated microchannel for the separation and simultaneous detection of AD, IN, and Hypo in an extracellular matrix of cancerous (A549) and non-cancerous (Vero) cells. The sensor probe confirms a higher basal level of extracellular AD and its metabolites in cancer cells compared to normal cells. In addition, the effect of dipyridamole on released adenosine in A549 cells was investigated.


Assuntos
Adenosina/isolamento & purificação , Técnicas Biossensoriais , Inosina/isolamento & purificação , Neoplasias/diagnóstico , Células A549 , Adenosina/química , Adenosina Desaminase/química , Eletrodos , Humanos , Hipoxantina/química , Inosina/química , Limite de Detecção , Metabolômica/métodos , Neoplasias/metabolismo , Neoplasias/patologia , Purina-Núcleosídeo Fosforilase/química , Xantina Oxidase/química
14.
Biosens Bioelectron ; 116: 108-115, 2018 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-29860089

RESUMO

Brain-derived neurotrophic factor (BDNF) was detected in the extracellular matrix of neuronal cells using a dual probe immunosensor (DPI), where one of them was used as a working and another bioconjugate loading probe. The working probe was fabricated by covalently immobilizing capture anti-BDNF (Cap Ab) on the gold nanoparticles (AuNPs)/conducting polymer composite layer. The bioconjugate probe was modified by drop casting a bioconjugate particles composed of conducting polymer self-assembled AuNPs, immobilized with detection anti-BDNF (Det Ab) and toluidine blue O (TBO). Each sensor layer was characterized using the surface analysis and electrochemical methods. Two modified probes were precisely faced each other to form a microfluidic channel structure and the gap between inside modified surfaces was about 19 µm. At optimized conditions, the DPI showed a linear dynamic range from 4.0 to 600.0 pg/ml with a detection limit of 1.5 ±â€¯0.012 pg/ml. Interference effect of IgG, arginine, glutamine, serine, albumin, and fibrinogene were examined and stability of the developed biosensor was also investigated. The reliability of the DPI sensor was evaluated by monitoring the extracellular release of BDNF using exogenic activators (ethanol, K+, and nicotine) in neuronal and non-neuronal cells. In addition, the effect of nicotine onto neuroblastoma cancer cells (SH-SY5Y) was studied in detail.


Assuntos
Técnicas Biossensoriais , Fator Neurotrófico Derivado do Encéfalo/análise , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Imunoensaio , Nicotina/farmacologia , Animais , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Fator Neurotrófico Derivado do Encéfalo/imunologia , Linhagem Celular Tumoral , Chlorocebus aethiops , Técnicas Eletroquímicas , Ouro/química , Humanos , Nanopartículas Metálicas/química , Nanocompostos/química , Neurônios/efeitos dos fármacos , Polímeros/química , Ratos , Células Vero
15.
East Mediterr Health J ; 13(5): 1098-107, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18290403

RESUMO

A survey was conducted in a low-endemic and in a non-endemic area of Sudan to evaluate the specificity and efficiency of different serological antibody detection techniques for Trypanosoma brucei gambiense. Comparisons were made of the card agglutination test for trypanosomiasis (CATT) on diluted blood, on diluted plasma and on eluates from blood dried on filter paper, the LATEX test on diluted plasma and an ELISA on diluted plasma and filter paper. The specificities of all the serological tests were not significantly different from CATT on diluted blood (99.5%). The specificity of CATT on diluted blood was similar (99.3%). The highest sensitivities (100%) were observed with CATT on diluted blood and with CATT and LATEX on diluted plasma. CATT on diluted blood was more cost-efficient than the classic test, CATT on whole blood.


Assuntos
Testes de Aglutinação/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Testes de Fixação do Látex/métodos , Trypanosoma brucei gambiense/imunologia , Tripanossomíase Africana/diagnóstico , Testes de Aglutinação/economia , Testes de Aglutinação/normas , Animais , Anticorpos Antiprotozoários/sangue , Anticorpos Antiprotozoários/imunologia , Estudos de Casos e Controles , Líquido Cefalorraquidiano/parasitologia , Análise Custo-Benefício , Estudos Transversais , Doenças Endêmicas/estatística & dados numéricos , Ensaio de Imunoadsorção Enzimática/economia , Ensaio de Imunoadsorção Enzimática/normas , Hematócrito , Humanos , Testes de Fixação do Látex/economia , Testes de Fixação do Látex/normas , Linfa/parasitologia , Programas de Rastreamento , Parasitologia/economia , Parasitologia/métodos , Vigilância da População , Estudos Prospectivos , Sensibilidade e Especificidade , Sudão/epidemiologia , Tripanossomíase Africana/sangue , Tripanossomíase Africana/epidemiologia , Tripanossomíase Africana/imunologia
16.
Biosens Bioelectron ; 98: 364-370, 2017 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-28704785

RESUMO

A microfluidic structured-dual electrodes sensor comprising of a pair of screen printed carbon electrodes was fabricated to detect acetylcholine, where one of them was used for an enzyme reaction and another for a detection electrode. The former was coated with gold nanoparticles and the latter with a porous gold layer, followed by electropolymerization of 2, 2:5,2-terthiophene-3-(p-benzoic acid) (pTTBA) on both the electrodes. Then, acetylcholinesterase was covalently attached onto the reaction electrode, and hydrazine and choline oxidase were co-immobilized on the detection electrode. The layers of both modified electrodes were characterized employing voltammetry, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, and quartz crystal microscopy. After the modifications of both electrode surfaces, they were precisely faced each other to form a microfluidic channel structure, where H2O2 produced from the sequential enzymatic reactions was reduced by hydrazine to obtain the analytical signal which was analyzed by the detection electrode. The microfluidic sensor at the optimized experimental conditions exhibited a wide dynamic range from 0.7nM to 1500µM with the detection limit of 0.6 ± 0.1nM based on 3s (S/N = 3). The biomedical application of the proposed sensor was evaluated by detecting acetylcholine in human plasma samples. Moreover, the Ca2+-induced acetylcholine released in leukemic T-cells was also investigated to show the in vitro detection ability of the designed microfluidic sensor. Interference due to the real component matrix were also studied and long term stability of the designed sensor was evaluated. The analytical performance of the designed sensor was also compared with commercially available ACh detection kit.


Assuntos
Acetilcolina/isolamento & purificação , Técnicas Biossensoriais/métodos , Leucemia de Células T/diagnóstico , Nanopartículas Metálicas/química , Acetilcolina/metabolismo , Acetilcolinesterase/química , Cálcio/química , Cálcio/metabolismo , Técnicas Eletroquímicas , Humanos , Leucemia de Células T/patologia , Limite de Detecção , Microfluídica , Linfócitos T/química , Linfócitos T/patologia
17.
AJNR Am J Neuroradiol ; 37(1): 37-43, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26471746

RESUMO

BACKGROUND AND PURPOSE: Texture analysis has been applied to medical images to assist in tumor tissue classification and characterization. In this study, we obtained textural features from parametric (relative CBV) maps of dynamic susceptibility contrast-enhanced MR images in glioblastoma and assessed their relationship with patient survival. MATERIALS AND METHODS: MR perfusion data of 24 patients with glioblastoma from The Cancer Genome Atlas were analyzed in this study. One- and 2D texture feature ratios and kinetic textural features based on relative CBV values in the contrast-enhancing and nonenhancing lesions of the tumor were obtained. Receiver operating characteristic, Kaplan-Meier, and multivariate Cox proportional hazards regression analyses were used to assess the relationship between texture feature ratios and overall survival. RESULTS: Several feature ratios are capable of stratifying survival in a statistically significant manner. These feature ratios correspond to homogeneity (P = .008, based on the log-rank test), angular second moment (P = .003), inverse difference moment (P = .013), and entropy (P = .008). Multivariate Cox proportional hazards regression analysis showed that homogeneity, angular second moment, inverse difference moment, and entropy from the contrast-enhancing lesion were significantly associated with overall survival. For the nonenhancing lesion, skewness and variance ratios of relative CBV texture were associated with overall survival in a statistically significant manner. For the kinetic texture analysis, the Haralick correlation feature showed a P value close to .05. CONCLUSIONS: Our study revealed that texture feature ratios from contrast-enhancing and nonenhancing lesions and kinetic texture analysis obtained from perfusion parametric maps provide useful information for predicting survival in patients with glioblastoma.


Assuntos
Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Glioblastoma/mortalidade , Glioblastoma/patologia , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Feminino , Humanos , Aumento da Imagem/métodos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Modelos de Riscos Proporcionais , Curva ROC
18.
Biosens Bioelectron ; 83: 312-8, 2016 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-27132006

RESUMO

Hypoxia inducible factor 1 alpha (HIF1α) overexpression was detected in cancerous cells using an amperometric immunosensor with a nano-bioconjugate. The sensor probe was fabricated by covalently immobilizing the antibody (anti-HIF1α) onto a composite layer of functionalized conducting polymer [2,2:5,2-terthiophene-3-(p-benzoic acid)] (pTTBA) formed on a layer of gold nanoparticles (AuNPs). A nano-bioconjugate with hydrazine and a secondary antibody of HIF1α (sec-Ab2) attached on AuNPs reveals the immunoreaction at the sensor probe through the catalytic reduction of H2O2 by hydrazine at -0.35V vs. Ag/AgCl. Morphology and performance of the sensor probe were characterized using FE-SEM, XPS, EIS, and cyclic voltammetry. The calibration plot at optimized experimental conditions shows a dynamic range of 25-350pM/mL with a detection limit of 5.35±0.02pM/mL. The reliability of the sensor was evaluated using non-cancerous Vero and cancerous MCF-7 cell lysates, where the HIF1α expression was compared with three cancerous cell lines MCF-7, PC-3, and A549. Furthermore, the sensor probe confirms the stable expression of HIF1α in the A549 lung cancer cells when exposing them to hypoxic mimicking agents Co, Ni, and Mn ions. Of these, Co ions show the highest stabilization effect on HIF1α followed by Ni and Mn ions, respectively.


Assuntos
Anticorpos Imobilizados/química , Técnicas Eletroquímicas/métodos , Subunidade alfa do Fator 1 Induzível por Hipóxia/análise , Neoplasias/patologia , Polímeros/química , Tiofenos/química , Benzoatos/química , Técnicas Biossensoriais/métodos , Linhagem Celular Tumoral , Ouro/química , Humanos , Imunoensaio/métodos , Nanopartículas Metálicas/química , Reprodutibilidade dos Testes
19.
Transplant Proc ; 37(2): 867-70, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15848559

RESUMO

UNLABELLED: Modified release (MR) tacrolimus is an extended release formulation administered once daily (qD). The purpose of this pharmacokinetic (PK) study was to evaluate tacrolimus exposure in stable kidney transplant recipients converted from Prograf twice a day to MR tacrolimus qD. METHODS: This was an open-label, multicenter study with a crossover design. Eligible patients were 18 to 65 years of age, more than 6 months posttransplant with stable renal function, and received stable Prograf doses more than 2 weeks prior to enrollment. Patients received Prograf twice a day through day 7; 24-hour PK profiles were obtained on days 1 and 7. Patients were converted to the same milligram-for-milligram daily dose of MR tacrolimus qD in the morning on day 8; 24-hour PK profiles were obtained for MR tacrolimus on days 8, 14, and 21. Laboratory and safety parameters were also evaluated. RESULTS: Most patients (67 of 70) completed all 5 PK profiles. The 90% confidence intervals (CI) for the MR tacrolimus vs Prograf comparison at steady state (days 14 and 21 vs days 1 and 7) were 90.7 and 99.4 for AUC0-24 and 82.7 and 91.9 for Cmin. MR tacrolimus was well tolerated with a safety profile comparable to that of Prograf. AUC0-24 was highly correlated to Cmin for Prograf (day 1, r = 0.80; day 7, r = 0.84) and MR tacrolimus (day 14, r = 0.92; day 21, r = 0.86). Renal function remained stable after conversion to MR tacrolimus. CONCLUSION: The steady state PK of MR tacrolimus are equivalent to Prograf after a milligram-for-milligram conversion in stable kidney transplant recipients. The results provide evidence to support a safe 1:1 conversion from Prograf twice a day to MR tacrolimus.


Assuntos
Transplante de Rim/imunologia , Tacrolimo/administração & dosagem , Tacrolimo/farmacocinética , Adulto , Idoso , Área Sob a Curva , Estudos Cross-Over , Preparações de Ação Retardada , Esquema de Medicação , Quimioterapia Combinada , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/farmacocinética , Imunossupressores/uso terapêutico , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Tacrolimo/uso terapêutico
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