Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Cancer Immunol Immunother ; 73(6): 109, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38662232

RESUMEN

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a highly immunosuppressive microenvironment. This single-blind, randomized study aimed to evaluate the synergistic immunomodulatory effects of synbiotics (probiotics and inulin prebiotics), as well as their impact on postoperative complications and outcomes, compared to the use of probiotics alone. Ninety patients diagnosed with PDAC were enrolled and randomly assigned into three groups: the placebo group, the probiotics group (receiving a mixture of ten strains of Lactobacillus, Bifidobacterium, and Streptococcus bacteria at a dose of 25 billion CFUs), and the synbiotics group (the same probiotics along with inulin prebiotics). The interventions were administered for 14 days before the surgery and continued for one month postoperatively. Tumor tissue infiltration of CD8 + T cells and the expression of IFN γ were assessed by immunohistochemistry (IHC). Inflammatory cytokines concentrations, including Il 1 B, IL 6, and IL 10, were evaluated as well by ELISA at various time points pre- and postoperative. Furthermore, patients were followed up after the surgery to assess postoperative short-term outcomes. Our results showed a significant elevation of CD8 + T cell proportion and IFN γ expression in the synbiotics group compared to the probiotics group (p = 0.049, p = 0.013, respectively). Inflammatory cytokines showed a significant gradual decrease in the synbiotics group compared to placebo and probiotics-treated groups (p = 0.000 for both). Administration of synbiotics and probiotics significantly decreased the rate of postoperative complications including anastomotic leakage, diarrhea, and abdominal distension (p = 0.032, p = 0.044, p = 0.042, respectively), with a remarkable reduction in bacteremia in the synbiotics group. These results revealed that this synbiotics formulation potentially enhances the immune response and reduces complications associated with surgery.Clinical trial identification: NCT06199752 (27-12-2023).


Asunto(s)
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Simbióticos , Humanos , Simbióticos/administración & dosificación , Masculino , Femenino , Carcinoma Ductal Pancreático/inmunología , Carcinoma Ductal Pancreático/cirugía , Carcinoma Ductal Pancreático/terapia , Carcinoma Ductal Pancreático/patología , Persona de Mediana Edad , Anciano , Neoplasias Pancreáticas/inmunología , Neoplasias Pancreáticas/cirugía , Probióticos/uso terapéutico , Probióticos/administración & dosificación , Método Simple Ciego , Citocinas/metabolismo , Complicaciones Posoperatorias/prevención & control , Linfocitos T CD8-positivos/inmunología
2.
Sci Rep ; 14(1): 7319, 2024 03 27.
Artículo en Inglés | MEDLINE | ID: mdl-38538635

RESUMEN

Compared to other infectious diseases, for which LFT development can take years, SARS-CoV-2 antigen LFTS were developed and deployed within months. LFTS for antigen detection were adopted on an unprecedented scale during the COVID-19 pandemic, but many of them lack the sensitivity especially for samples with low viral load. In our previous work, we developed an enhanced signal strip for detection of SARS CoV-2 SI antigens in saliva. Here we introduce some modification to improve the sensitivity, and specificity, and to lower the cost of the strip, by using biotin streptavidin (BS) system. In the modified BS strip, gold-streptavidin and biotinylated Nanobodies (Nbs) against S1 antigen were externally mixed with the tested samples (saliva or nasopharyngeal swab) before their application on the sample pad of the test strip containing angiotensin converting enzyme (ACE-2), as the capturing probe. The study included 320 individuals, with 180 being positively confirmed by RT-PCR and 140 confirmed negative, as well as, 45 health care workers, who were responsible for screening and handling of surgical cases in General Surgery Department and COVID clinic of TBRI. Our results proved that modified BS strip improved the overall sensitivity and specificity of S1antigen detection in saliva samples (95.21% and 99.29% respectively) compared to our previously developed enhanced LFTS (91.66% and 98.57% respectively). Also, the sensitivity of cases with Ct ≤ 30, Ct ≤ 35, and Ct ≤ 40 using the modified BS strip showed higher values (98.54%, 95.38%, and 88.89% respectively), compared to the corresponding results of our previously developed enhanced LFTS (95.86%, 92.31%, and 82.22% respectively). There were no cross-reactions with either Middle East respiratory syndrome corona virus MERS-CoV or SARS-CoV antigens. Furthermore, we found that the lower viral detection limit (LVD) of BS strip was obviously lower than our previous LVD limit of the enhanced LFTS (0.2 × 104 copies/ml vs. 0.4 × 104 copies/ml, respectively). Our developed BS strip showed that saliva samples gave better results than nasopharyngeal swabs of the same patients. The fact of using smaller amounts of Nbs, and ACE2, as well as the dispensing off of conjugate pad when applying BS strip modifications, justified the expected reduction in the costs of the strip. The implementation of BS strips on saliva samples of 45 health co-workers, who were tested 4 and 6 days after exposure to infection, showed an increase in the sensitivity, starting from the 4th day and reaching its highest level on the 6th day in both high risk and paramedic groups (90.9%, and 80.0%, respectively). This study provides evidence that employment of the modified BS system could increase the sensitivity of the strips, lower their cost, and render them an effective screening tool for early detection of the virus in saliva of suspected Covid-19 patients.


Asunto(s)
Biotina , COVID-19 , Proteínas de Neoplasias , Humanos , Estreptavidina , SARS-CoV-2 , Pandemias , Saliva , COVID-19/diagnóstico , Antígenos Virales , Nasofaringe , Manejo de Especímenes
3.
Sci Rep ; 13(1): 10643, 2023 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-37391465

RESUMEN

Despite the transfer of COVID-19 from the pandemic to control, we are still in a state of uncertainty about long-term success. Therefore, there is a great need for rapid and sensitive diagnostics to sustain the control status. After several optimization trials, we developed lateral flow test (LFT) strips for rapid detection of SARS-CoV-2 spike 1 (S1) antigen in saliva samples. For signal enhancement of our developed strips, we applied dual gold conjugates. Gold-labeled anti-S1 nanobodies (Nbs) were employed as S1 detector conjugate, while gold-labeled angiotensin-converting enzyme 2 (ACE2) was used as S1 capturing conjugate. In a parallel strip design, we used an anti-S1 monoclonal antibody (mAb) as an antigen detector instead of anti-S1 Nbs. Saliva samples were collected from 320 symptomatic subjects (180 RT-PCR confirmed positive cases and 140 confirmed negative cases) and were tested with the developed strips. In early detection for positive samples with cycle threshold (Ct ≤ 30), Nbs-based LFT strips showed higher sensitivity (97.14%) and specificity (98.57%) than mAb-based strips which gave 90.04% sensitivity and 97.86% specificity. Moreover, the limit of detection (LoD) for virus particles was lower for Nbs-based LFT (0.4 × 104 copies/ml) than for the mAb-based test (1.6 × 104 copies/ml). Our results are in favor of the use of dual gold Nbs and ACE2 conjugates in LFT strips. These signal-enhanced strips offer a sensitive diagnostic tool for rapid screening of SARS-CoV-2 S1 antigen in the easily collected saliva samples.


Asunto(s)
COVID-19 , Anticuerpos de Dominio Único , Humanos , SARS-CoV-2 , COVID-19/diagnóstico , Enzima Convertidora de Angiotensina 2 , Saliva , Anticuerpos Monoclonales
4.
Trop Med Infect Dis ; 7(6)2022 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-35736981

RESUMEN

The development of sensitive, non-invasive tests for the detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antigens is imperative, and it is still challenging to manage the extent of infection throughout the population. Here, we designed and optimized a sandwich enzyme-linked immunosorbent assay (ELISA) protocol for SARS-CoV-2 S1 antigen detection in saliva. Both saliva samples and nasopharyngeal swabs were collected from 220 real-time quantitative polymerase chain reaction (RT-qPCR)-confirmed positive and negative cases. S1 protein receptor-binding domain (RBD) nanobodies were efficiently conjugated with 40 nm gold nanoparticles (AuNPs) and employed as antigen detection probes in the developed system, while recombinant S1 monoclonal antibodies (S1mAbs) were employed as antigen capture probes. After checkerboard assays and system optimization, the clinical samples were tested. In saliva, the developed ELISA system showed the highest sensitivity (93.3) for samples with cycle threshold (Ct) values ≤ 30; interestingly, high sensitivity (87.5 and 86%) was also achieved for samples with Ct values ≤ 35 and ≤40, respectively, compared with 90, 80 and 88% sensitivity rates for nasopharyngeal swabs with the same categorized Ct values. However, the specificity was 100%, and no cross-reactions were detected with Middle East respiratory syndrome coronavirus (MERS-CoV) or SARS-CoV antigens. These results reveal that our protocol could be established as an efficient and sensitive, non-invasive diagnostic tool for the early detection of SARS-CoV-2 infection using easily collectable saliva samples.

5.
Exp Clin Transplant ; 20(1): 62-68, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-33928878

RESUMEN

OBJECTIVES: Hepatocellular carcinoma is the fourth leading cause of cancer deaths in the world. Conven - tional methods of cancer therapy are either invasive or have undesirable side effects. Therefore, exploring new therapeutic strategies to control the progression of hepatocellular carcinoma, such as cell-based therapies, is a key issue for prolonging patient survival. In this study, we aimed to evaluate tumor suppressive effects of mesenchymal stem cells on the in vivo pro - gression of hepatocellular carcinoma in murine model. MATERIALS AND METHODS: Hepatocellular carcinoma was induced in 40 rats with diethylnitrosamine. Rats were divided into 4 groups: 1 group injected with diethylnitrosamine only, 1 group injected with diethylnitrosamine and 1 dose of rat bone marrowderived mesenchymal stem cells, 1 group injected with diethylnitrosamine and 2 doses of rat bone marrowderived mesenchymal stem cells, and 1 group was injected with diethylnitrosamine and 3 doses of rat bone marrow-derived mesenchymal stem cells. Rats were killed after 1 month of dose 3. Liver specimens were histopathologically examined, and serum samples were examined for liver function and cytokines. RESULTS: Histopathological examination revealed that mesenchymal stem cell transplant induced liver regeneration. It also improved liver function as revealed by decreased levels of alanine and aspartate aminotransferase. Mesenchymal stem cells also repaired the immunopathology of the liver environment, as it decreased levels of interleukin 2 and 10, tumor necrosis factor α, and interferon γ. CONCLUSIONS: Mesenchymal stem cell infusion significantly enhanced hepatic structure and function of livers in a rat hepatocellular carcinoma model.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas , Animales , Médula Ósea/patología , Carcinoma Hepatocelular/inducido químicamente , Carcinoma Hepatocelular/terapia , Dietilnitrosamina/toxicidad , Modelos Animales de Enfermedad , Humanos , Hígado/patología , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/terapia , Células Madre Mesenquimatosas/patología , Ratones , Pronóstico , Ratas , Resultado del Tratamiento
6.
Dig Dis ; 39(5): 534-539, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33440370

RESUMEN

INTRODUCTION: Malignant ascites results from imbalance between protein in the peritoneal cavity and absorption of fluids via the lymphatic system. More than 20 interleukins (ILs) are known to play an important role in the protection against tumors. MATERIALS AND METHODS: Ascitic fluid IL-1B, IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ levels were assessed in 45 patients with liver cirrhosis and ascites as judged by histopathological and ultrasonographic findings. They were divided into 2 groups according to presence of hepatic focal lesions. Ten patients with focal hepatic lesions were randomly selected and subjected to analysis of serum levels of IL-2 and IL-10. RESULTS: Ascitic fluid IL-4, IL-6 and IL-10 levels were found to be significantly higher in patients with hepatocellular carcinoma (HCC) than patients with cirrhosis. TNF-α, and IFN-γ were also found to be higher in HCC than patients with cirrhosis but with no significance. On the other hand, there was no significant difference in levels of IL-1B and IL-2 between the 2 groups. Ascitic fluid IL-2 and IL-10 levels were found to be higher in ascitic fluid than in serum of the same patients. CONCLUSION: Ascitic fluid levels of IL-4, IL-6 and IL-10 are higher in HCC patients than patients with cirrhosis alone. Levels of ascitic fluid IL-2 and IL-10 proved to be a better prognostic tool than their levels in sera of the same patients. To conclude, patients with cirrhosis may be subjected to scheduled examination of ascitic fluid cytokines to predict transformation into HCC.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Ascitis , Líquido Ascítico , Citocinas , Humanos , Cirrosis Hepática/complicaciones , Pronóstico
7.
Cell Reprogram ; 22(3): 134-146, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32243193

RESUMEN

Mesenchymal stem cell (MSC)-based liver tissue engineering on nanofibrous scaffold holds great promise for cell-based therapy in liver injuries and end-stage liver failure treatments. MSCs were generated from umbilical cord blood. Hepatogenic differentiation was induced on two-dimensional (2D) and three-dimensional (3D) culture system and characterized by morphology, scanning electron microscopy, immunocytochemistry, and gene expression. Albumin and α-1 antitrypsin (AAT) in culture supernatants were measured. Differentiated cells were administered intravenous into a murine model of carbon tetra induced liver cirrhosis. After 12 weeks of injection, liver pathology was examined. The hepatogenic differentiated MSCs stained positively for albumin, alpha fetoprotein, HepPar1, cytokeratin 7 and 18, and OV6 with more mature cells, hexagonal in shape with central nuclei forming large sheets in groups in 3D culture system. AAT secretion and indocyanine green uptake were significantly increased in 3D system. In experimental model, MSC-3D treated group exhibited maximal restoration of liver architecture with absent septal fibrosis and marked improvement of alanine transaminase (ALT) and aspartate transaminase (AST), and mild increase in albumin. Both 3D and 2D culture system are effective in functional hepatogenic differentiation from MSCs and serve as a vehicle in liver tissue engineering. In vivo hepatogenic differentiation is more effective on 3D scaffold, with better functional recovery.


Asunto(s)
Diferenciación Celular , Enfermedad Hepática en Estado Terminal/terapia , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/citología , Animales , Femenino , Sangre Fetal/citología , Hepatocitos/metabolismo , Humanos , Hígado , Células Madre Mesenquimatosas/metabolismo , Ratones , Ratones Endogámicos BALB C , Modelos Teóricos , Regeneración
8.
Exp Clin Transplant ; 17(2): 251-258, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30346265

RESUMEN

OBJECTIVES: Liver transplantation is the well-known treatment for chronic liver diseases; however, postoperative complications and lack of donors continue to be limitations with this treatment. Investigating new modalities for treatment of chronic liver illness is a must. In the present study, we aimed to clarify the effects of an in vitro hepatocyte-differentiated human unrestricted somatic stem cell transplant as a new cell-based therapy in an experimental model of chronic liver failure. MATERIALS AND METHODS: Human umbilical cord blood-derived unrestricted somatic stem cells were isolated, cultured, propagated, and characterized. Cells were directed to differentiate into hepatocyte-like cells. An animal model of carbon tetrachloride cirrhotic liver failure was prepared, and the human in vitro differentiated unrestricted somatic stem cells were transplanted into the experimental model. Animals that did not receive transplant served as the pathologic control group. Animals were euthanized 12 weeks after transplant, and liver functions and histopathology were assessed. RESULTS: Compared with the pathologic control group, the transplant group showed improvements in levels of alanine aminotransferase, aspartate aminotransferase, albumin, and bilirubin. Histopathologic examination of the transplant group also showed improvements in hydropic degeneration and fibrosis. CONCLUSIONS: The use of unrestricted somatic stem cells, isolated and propagated from cord blood and then differentiated into hepatocyte-like cells, improved both fibrosis and normal function of cirrhotic livers. These cells could be considered as a line of cell-based therapy in cases of chronic liver disease.


Asunto(s)
Células Madre Adultas/trasplante , Enfermedad Hepática Inducida por Sustancias y Drogas/cirugía , Trasplante de Células Madre de Sangre del Cordón Umbilical/métodos , Sangre Fetal/citología , Hepatocitos/trasplante , Cirrosis Hepática Experimental/cirugía , Regeneración Hepática , Hígado/patología , Células Madre Adultas/metabolismo , Animales , Biomarcadores/metabolismo , Tetracloruro de Carbono , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Hepatocitos/metabolismo , Humanos , Hígado/metabolismo , Cirrosis Hepática Experimental/inducido químicamente , Cirrosis Hepática Experimental/metabolismo , Cirrosis Hepática Experimental/patología , Ratones Endogámicos BALB C , Fenotipo , Factores de Tiempo
9.
Adv Clin Exp Med ; 27(10): 1329-1339, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30048056

RESUMEN

BACKGROUND: The liver is one of the major target organs for which cell-based therapies are very promising. The limitations of various cellular therapies, including bone marrow (BM)-derived mesenchymal stem cells (MSCs), urges the exploration of stem cell sources more suitable for transplantation. Human umbilical cord blood (HUCB) can overcome these drawbacks with a favorable reparative outcome. OBJECTIVES: The aim of this study was to evaluate the therapeutic potential of MSCs in 2 groups of chronic liver injury experimental models. MATERIAL AND METHODS: Propagation and characterization of MSCs isolated from cord blood (CB) samples were performed and differentiation into osteogenic, adipogenic and hepatogenic lineages was induced. The 1st experimental model group (80 mice) included a negative control, a pathological control and 60 mice infected with Schistosoma mansoni (S. mansoni) and transplanted with MSCs. The 2nd experimental model group (30 hamsters) included 10 healthy hamsters serving as a negative control and 20 hamsters injected with repeated doses of carbon tetrachloride (CCl4) to induce liver fibrosis; 10 of them were treated with an intrahepatic (IH) injection of 3 × 106 MSCs and the other 10 were untreated pathological controls. Mice and hamsters were sacrificed 12 weeks post-transplantation and their liver sections were stained immunohistochemically for the detection of human hepatocyte-like cells. Moreover, the sections were examined for the levels of fibrosis. RESULTS: In both models, the transplantation of CB-derived MSCs (CB-MSCs) resulted in the engraftment of the fibrotic livers with newly formed hepatocytes, as evidenced by positive immunohistochemistry staining with human Hepatocyte Paraffin 1 (Hep Par 1), alpha-fenoprotein (AFP), cytokeratin 18 (CK18), cytokeratin 7 (CK7), and OV6 monoclonal antibody. The transplanted liver sections showed markedly reduced hepatic fibrosis with a significantly lower fibrotic index, as well as significantly improved liver functions compared to the pathological control (p < 0.001). CONCLUSIONS: This data provides hope that human CB-MSCs can be utilized as multipotent stem cells with unlimited potentiality in regenerative medicine and supports the concept of cellular therapy for the cure of hepatic fibrosis.


Asunto(s)
Diferenciación Celular , Cirrosis Hepática/terapia , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/citología , Animales , Sangre Fetal , Hepatocitos/metabolismo , Humanos , Hígado , Células Madre Mesenquimatosas/metabolismo , Ratones , Modelos Teóricos
10.
Exp Clin Transplant ; 16(1): 81-89, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28585911

RESUMEN

OBJECTIVES: Liver transplant is the cornerstone line of treatment for chronic liver diseases; however, the long list of complications and obstacles stand against this operation. Searching for new modalities for treatment of chronic liver illness is a must. In the present research, we aimed to compare the effects of transplant of undifferentiated human mesenchymal stem cells, in vitro differentiated mesenchymal stem cells, and adult hepatocytes in an experimental model of chronic liver failure. MATERIALS AND METHODS: Undifferentiated human cord blood mesenchymal stem cells were isolated, pro-pagated, and characterized by morphology, gene expression analysis, and flow cytometry of surface markers and in vitro differentiated into hepatocyte-like cells. Rat hepatocytes were isolated by double perfusion technique. An animal model of chronic liver failure was developed, and undifferentiated human cord blood mesenchymal stem cells, in vitro hepato-genically differentiated mesenchymal stem cells, or freshly isolated rat hepatocytes were transplanted into a CCL4 cirrhotic experimental model. Animals were killed 3 months after transplant, and liver functions and histopathology were assessed. RESULTS: Compared with the cirrhotic control group, the 3 cell-treated groups showed improved alanine aminotransferase, aspartate aminotransferase, albumin, and bilirubin levels, with best results shown in the hepatocyte-treated group. Histopathologic examination of the treated groups showed improved fibrosis, with best results obtained in the undifferentiated mesenchymal stem cell-treated group. CONCLUSIONS: Both adult hepatocytes and cord blood mesenchymal stem cells proved to be promising candidates for cell-based therapy in liver regeneration on an experimental level. Improved liver function was evident in the hepatocyte-treated group, and fibrosis control was more evident in the undifferentiated mesenchymal stem cell-treated group.


Asunto(s)
Diferenciación Celular , Enfermedad Hepática Inducida por Sustancias y Drogas/cirugía , Trasplante de Células Madre de Sangre del Cordón Umbilical , Enfermedad Hepática en Estado Terminal/cirugía , Hepatocitos/trasplante , Cirrosis Hepática Experimental/cirugía , Trasplante de Hígado/métodos , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas , Animales , Biomarcadores/metabolismo , Tetracloruro de Carbono , Células Cultivadas , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Enfermedad Hepática Inducida por Sustancias y Drogas/fisiopatología , Enfermedad Hepática en Estado Terminal/inducido químicamente , Enfermedad Hepática en Estado Terminal/patología , Enfermedad Hepática en Estado Terminal/fisiopatología , Hepatocitos/metabolismo , Humanos , Cirrosis Hepática Experimental/inducido químicamente , Cirrosis Hepática Experimental/patología , Cirrosis Hepática Experimental/fisiopatología , Regeneración Hepática , Masculino , Células Madre Mesenquimatosas/metabolismo , Ratones Endogámicos BALB C , Fenotipo , Ratas Endogámicas Lew , Recuperación de la Función , Factores de Tiempo
11.
Talanta ; 119: 467-72, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24401442

RESUMEN

Sensitive disposable potentiometric sensors for determination of the organophosphorus pesticide (OPs), ethion and its degradation residues have been constructed. The fabricated screen printed sensors are based on multi-walled carbon nanotube-polyvinyl chloride (MWNT-PVC) composite incorporated with α-cyclodextrin (α-CD) ionophore for butyrylcholine (BuCh) determination. Butyrylcholinesterase (BuChE) activity was measured through monitoring the BuCh hydrolysis using the fabricated sensors. The electrode potential changes linearly with BuChE concentration over the range from 0.04 to 0.4 U in phosphate buffer solution. This approach can also be used to analyze ethion and its degradation products in the concentration range from 0 to 330 ng mL(-1) by measuring the relative inhibition percentage of BuChE. From different ethion degradation products, inhibition by dioxon and monooxon were more potent than the parent pesticide. The proposed method was applied for determination of ethion in different samples with good accuracy and precision. The relative simple fabrication protocol of biosensor, high sensitivity and stability represents a promising approach for determination of environmental pollutants in field conditions.


Asunto(s)
Técnicas Biosensibles , Compuestos Organotiofosforados/análisis
12.
Analyst ; 137(23): 5680-7, 2012 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-23050261

RESUMEN

Miniaturized potentiometric sensors based on ß-cyclodextrins (ß-CDs) are described for determination of metformin (Mf) in pharmaceutical preparations and biological fluids. Electrode matrix compositions are optimized on the basis of the nature and content of sensing ionophore, ionic sites and plasticizers. Coated wire electrodes (CWEs) modified with heptakis(2,3,6-tri-O-methyl)-ß-CD, sodium tetrakis(4-fluorophenyl)borate (NaTFPB) and 2-fluorophenyl 2-nitrophenyl ether (f-NPE), work satisfactorily in the concentration range from 10(-6) to 10(-1) mol L(-1) with Nernstian compliance (55.7 ± 0.4 mV per decade activity) and a detection limit of 8 × 10(-7) mol L(-1). Incorporation of ß-CD as a molecular recognition element improved the electrode sensitivity and selectivity due to encapsulation of Mf into the ß-CD cavity (host-guest interaction). The developed electrodes have been successfully applied for the potentiometric determination of Mf under batch and flow injection analysis (FIA). FIA allows analysis of 90 samples per h offering the advantages of simplicity, accuracy and automation feasibility. The dissolution profile for metformin pharmaceutical samples (Cidophage®) was monitored using the proposed electrode in comparison with the official spectrophotometric methods. Characterization of the formed Mf-ß-CD inclusion complexes is discussed in detail.


Asunto(s)
Líquidos Corporales/química , Metformina/análisis , Potenciometría/métodos , beta-Ciclodextrinas/química , Análisis de Inyección de Flujo/métodos , Humanos , Electrodos de Iones Selectos , Ionóforos , Masculino , Metformina/química , Miniaturización , Preparaciones Farmacéuticas/química , Plastificantes
13.
Talanta ; 97: 96-102, 2012 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-22841052

RESUMEN

A novel carbon paste electrode based on functionlized multi-walled carbon nanotubes/ß-cyclodextrin composite (FMWCNTs/ß-CD-CPE) is described for potentiometric determination of piroxicam (PXM). Improved sensitivity and selectivity was achieved by application of CDs as molecular host-guest recognition elements and MWCNTs. The electrochemical performance of carbon paste electrodes incroporated with FMWCNTs/ß-CD composite was compared to those incroporated with MWCNTs and free CDs. Matrices compositions of each electrode are optimized on the basis of nature and content of the modifier, ionic sites and selected plasticizer. CPEs containing FMWCNTs/ß-CD composite, hyamine (Hy) and 2-fluorophenyl 2-nitrophenyl ether (f-NPE) as electrode plasticizer, work satisfactory in the concentration range from 10(-6) to 10(-2) mol L(-1) with Nernstain compliance (58.7±0.9 mV decade(-1) activity) with fast response time of about 2s and exhibit adequate operational lifetime (16 weeks). The developed electrodes have been applied for the potentiometric determination of PXM in pharmaceutical formulation under batch and flow injection analysis (FIA). FIA allows the analysis of 120 samples h(-1) with the advantage of simplicity, accuracy and automation feasibility.


Asunto(s)
Análisis de Inyección de Flujo/métodos , Nanotubos de Carbono/química , Piroxicam/análisis , Potenciometría/métodos , beta-Ciclodextrinas/química , Electrodos , Análisis de Inyección de Flujo/instrumentación , Ionóforos/química , Pomadas , Piroxicam/química , Potenciometría/instrumentación
14.
J Egypt Soc Parasitol ; 36(3): 945-58, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17153705

RESUMEN

Diagnosis and quantification of Echinococcus granulosus infection in man and animal hosts are centralized to feasible control. This study included 93 serum samples, 25 sure positive hydatid cases confirmed surgically, 7 suspected cases diagnosed by indirect haemagglutination IHA and 41 cases other parasitic infections (15 S. mansoni, 8 Fasciola, 7 Ascaris, 5 H. nana & 6 Ancylostoma) diagnosed by microscopic examination and were negative by ELISA and/or IHA for anti-hydatid antibody. Twenty negative serum samples served as healthy controls. Six types of hydatid fluid antigens (crude, host-free & Con-A purified) of human and camel origin were subjected to electrophoretic separation (SDS-PAGE) and immunoblotting (EITB). The anti-hydatid IgG was detected in sera of the different groups for evaluation of sensitivity, specificity and diagnostic efficacy of each type of antigens. Detection of circulating hydatid antigen (CAg) was performed using anti rabbit hyperimmune sera raised against Con-A purified either human or camel hydatid antigen. SDS-PAGE revealed several bands ranging from 55-185 kDa with 10 kDa band shared by all antigens. The specific bands revealed by EITB for Con-A purified camel and human antigens were at 80, 110 & 55, 110 kDa respectively. ELISA highest sensitivity (96.9%) was by using host-free Con-A purified glycoprotein fraction of human hydatid antigen. Highest specificity (98.4%) was recorded upon use of either Con-A purified camel or human antigen with 94.5% & 97.7% diagnostic efficacy respectively. Detection of circulating antigen by polyclonal antibodies against Con-A purified human hydatid antigen revealed 91.8% specificity.


Asunto(s)
Equinococosis/diagnóstico , Echinococcus granulosus , Proteínas del Helminto , Animales , Anticuerpos Antihelmínticos/sangre , Antígenos Helmínticos/inmunología , Camelus , Echinococcus granulosus/química , Echinococcus granulosus/inmunología , Echinococcus granulosus/aislamiento & purificación , Electroforesis en Gel de Poliacrilamida/métodos , Femenino , Proteínas del Helminto/aislamiento & purificación , Humanos , Immunoblotting/métodos , Inmunoglobulina G/sangre , Masculino , Peso Molecular , Receptores de Concanavalina A , Sensibilidad y Especificidad
15.
J Egypt Soc Parasitol ; 36(3): 993-1006, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17153708

RESUMEN

The evidence based data of hydatid liver disease indicate that the level of evidence was too low to help decide between radical or conservative surgeries (level IV evidence, grade C recommendation). So, there is a need for accurately designed randomized trials with precise goals to compare pericystectomy versus a specific modified endocystectomy technique for the treatment of hepatic hydatid cysts 8 cm or less in diameter in Egyptian patients, regarding the operative time, intra-operative blood loss, complications and long-term recurrence and to test the role of anti-hydatid IgG4 in diagnosis and detection of early recurrence. 60 patients with 131 liver cysts of E. granulosus fulfilling the study criteria were randomly divided to two groups. GI: 32 patients with 69 cysts treated by modified endocystectomy and GII: 28 patients with 62 cysts treated by closed total pericystectomy. GIa included 40 cysts >5 cm in diameter (mean 6.86, SD+/-0.809) & GIb 29 cysts < or = 5 cm in diameter (mean 4.17 SD+/-0.83). GIIa included 37 cysts >5 cm in diameter (mean 7.01 SD+/+0.79) & GIIb 25 cysts < or = 5 cm in diameter (mean 4.04 SD+/-0.93). Preoperative evaluation included history taking, clinical examination, blood tests, specific anti-hydatid IgG4, abdominal sonography and CT scan. The operative time for dealing with each cyst was in minutes. Operative blood loss and need for blood transfusion were estimated for each patient. Specific anti-hydatid IgG4 by ELISA was used to diagnose and to detect early recurrence. Patients were followed up clinically and by ultrasonography every 3 months and for anti-hydatid IgG4 every 6 months for 24-90 months. The mean maximum operative time was in GIIa followed by GIa, GIb, then GIIb. The operative time was significantly lower in GIIb than Ib and in GIa than IIa. Seven patients (GII) had blood transfusion. The intraoperative bleeding in GI was <500 ml/ patient, and 18 patients (GII) each bled >500 ml. No intraperitoneal seedling during the follow up. 5 of 55 patients (9%) were serologically suspected of relapse or incomplete cure. One (GII) showed early recurrence at 3 months. High IgG4 antibodies were detected in patients which decreased gradually after surgery and normal after 18 months post-operation.


Asunto(s)
Pérdida de Sangre Quirúrgica , Equinococosis Hepática/cirugía , Echinococcus granulosus , Complicaciones Posoperatorias/epidemiología , Adulto , Anciano , Animales , Transfusión Sanguínea , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Estudios de Seguimiento , Humanos , Inmunoglobulina G , Masculino , Persona de Mediana Edad , Recurrencia , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...