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Banat R, Daoud S, Taha MO. Ligand-based pharmacophore modeling and machine learning for the discovery of potent aurora A kinase inhibitory leads of novel chemotypes. Mol Divers 2024:10.1007/s11030-024-10814-y. [PMID: 38446372 DOI: 10.1007/s11030-024-10814-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 01/19/2024] [Indexed: 03/07/2024]
Abstract
Aurora-A (AURKA) is serine/threonine protein kinase involved in the regulation of numerous processes of cell division. Numerous studies have demonstrated strong association between AURKA and cancer. AURKA is overexpressed in many cancers, such as colon, breast and prostate cancers. Consequently, AURKA has emerged as promising target for therapeutic intervention in cancer management. Herein, we describe a computational workflow for the discovery of novel anti-AURKA inhibitory leads starting with ligand-based assessment of the pharmacophoric space of six diverse sets of inhibitors. Subsequently, machine learning/QSAR modeling was coupled with genetic function algorithm to search for the best possible combination of machine learner, ligand-based pharmacophore(s) and molecular descriptors capable of explaining variation in anti-AURKA bioactivities within a collected list of inhibitors. Two learners succeeded in achieving acceptable structure/activity correlations, namely, random forests and extreme gradient boosting (XGBoost). Three pharmacophores emerged in the successful ML models. These were then used as 3D search queries to mine the National Cancer Institute database for novel anti-AURKA leads. Top-ranking 38 hits were assessed in vitro for their anti-AURKA bioactivities. Among them, three compounds exhibited promising dose-response curves, demonstrating experimental IC50 values ranging from sub-micromolar to low micromolar values. Remarkably, two of these compounds are of novel chemotypes.
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Affiliation(s)
- Rajaa Banat
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Jordan, Amman, Jordan
| | - Safa Daoud
- Department of Pharmaceutical Chemistry and Pharmacognosy, Faculty of Pharmacy, Applied Sciences Private University, Amman, Jordan
| | - Mutasem Omar Taha
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Jordan, Amman, Jordan.
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Jaradat NJ, Hatmal M, Alqudah D, Taha MO. Computational workflow for discovering small molecular binders for shallow binding sites by integrating molecular dynamics simulation, pharmacophore modeling, and machine learning: STAT3 as case study. J Comput Aided Mol Des 2023; 37:659-678. [PMID: 37597062 DOI: 10.1007/s10822-023-00528-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 07/26/2023] [Indexed: 08/21/2023]
Abstract
STAT3 belongs to a family of seven transcription factors. It plays an important role in activating the transcription of various genes involved in a variety of cellular processes. High levels of STAT3 are detected in several types of cancer. Hence, STAT3 inhibition is considered a promising therapeutic anti-cancer strategy. However, since STAT3 inhibitors bind to the shallow SH2 domain of the protein, it is expected that hydration water molecules play significant role in ligand-binding complicating the discovery of potent binders. To remedy this issue, we herein propose to extract pharmacophores from molecular dynamics (MD) frames of a potent co-crystallized ligand complexed within STAT3 SH2 domain. Subsequently, we employ genetic function algorithm coupled with machine learning (GFA-ML) to explore the optimal combination of MD-derived pharmacophores that can account for the variations in bioactivity among a list of inhibitors. To enhance the dataset, the training and testing lists were augmented nearly a 100-fold by considering multiple conformers of the ligands. A single significant pharmacophore emerged after 188 ns of MD simulation to represent STAT3-ligand binding. Screening the National Cancer Institute (NCI) database with this model identified one low micromolar inhibitor most likely binds to the SH2 domain of STAT3 and inhibits this pathway.
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Affiliation(s)
- Nour Jamal Jaradat
- Department of Medical Laboratory Sciences, Faculty of Applied Health Sciences, The Hashemite University, P.O. Box 330127, Zarqa, 13133, Jordan
| | - Mamon Hatmal
- Department of Medical Laboratory Sciences, Faculty of Applied Health Sciences, The Hashemite University, P.O. Box 330127, Zarqa, 13133, Jordan
| | - Dana Alqudah
- Cell Therapy Center, the University of Jordan, Amman, 11942, Jordan
| | - Mutasem Omar Taha
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Jordan, Amman, Jordan.
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Jaradat NJ, Hatmal M, Alqudah D, Taha MO. Correction to: Computational workflow for discovering small molecular binders for shallow binding sites by integrating molecular dynamics simulation, pharmacophore modeling, and machine learning: STAT3 as case study. J Comput Aided Mol Des 2023; 37:679. [PMID: 37855953 DOI: 10.1007/s10822-023-00540-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Affiliation(s)
- Nour Jamal Jaradat
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, The University of Jordan, Amman, Jordan
| | - Mamon Hatmal
- Department of Medical Laboratory Sciences, Faculty of Applied Health Sciences, The Hashemite University, P.O. Box 330127, Zarqa, 13133, Jordan
| | - Dana Alqudah
- Cell Therapy Center, The University of Jordan, Amman, 1942, Jordan
| | - Mutasem Omar Taha
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, The University of Jordan, Amman, Jordan.
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Jaradat NJ, Alshaer W, Hatmal M, Taha MO. Discovery of new STAT3 inhibitors as anticancer agents using ligand-receptor contact fingerprints and docking-augmented machine learning. RSC Adv 2023; 13:4623-4640. [PMID: 36760267 PMCID: PMC9896621 DOI: 10.1039/d2ra07007c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 01/28/2023] [Indexed: 02/05/2023] Open
Abstract
STAT3 belongs to a family of seven vital transcription factors. High levels of STAT3 are detected in several types of cancer. Hence, STAT3 inhibition is considered a promising therapeutic anti-cancer strategy. In this work, we used multiple docked poses of STAT3 inhibitors to augment training data for machine learning QSAR modeling. Ligand-Receptor Contact Fingerprints and scoring values were implemented as descriptor variables. Escalating docking-scoring consensus levels were scanned against orthogonal machine learners, and the best learners (Random Forests and XGBoost) were coupled with genetic algorithm and Shapley additive explanations (SHAP) to identify critical descriptors that determine anti-STAT3 bioactivity to be translated into pharmacophore model(s). Two successful pharmacophores were deduced and subsequently used for in silico screening against the National Cancer Institute (NCI) database. A total of 26 hits were evaluated in vitro for their anti-STAT3 bioactivities. Out of which, three hits of novel chemotypes, showed cytotoxic IC50 values in the nanomolar range (35 nM to 6.7 μM). However, two are potent dihydrofolate reductase (DHFR) inhibitors and therefore should have significant indirect STAT3 inhibitory effects. The third hit (cytotoxic IC50 = 0.44 μM) is purely direct STAT3 inhibitor (devoid of DHFR activity) and caused, at its cytotoxic IC50, more than two-fold reduction in the expression of STAT3 downstream genes (c-Myc and Bcl-xL). The presented work indicates that the concept of data augmentation using multiple docked poses is a promising strategy for generating valid machine learning models capable of discriminating active from inactive compounds.
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Affiliation(s)
- Nour Jamal Jaradat
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Jordan Amman 11492 Jordan +962 6 5339649 +962 6 5355000 ext. 23305
| | - Walhan Alshaer
- Cell Therapy Center, The University of Jordan Amman 11942 Jordan
| | - Mamon Hatmal
- Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, The Hashemite University P.O. Box 330127 Zarqa 13133 Jordan
| | - Mutasem Omar Taha
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Jordan Amman 11492 Jordan +962 6 5339649 +962 6 5355000 ext. 23305
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Al-Tawil MF, Daoud S, Hatmal MM, Taha MO. Discovery of new Cdc2-like kinase 4 (CLK4) inhibitors via pharmacophore exploration combined with flexible docking-based ligand/receptor contact fingerprints and machine learning. RSC Adv 2022; 12:10686-10700. [PMID: 35424985 PMCID: PMC8982525 DOI: 10.1039/d2ra00136e] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 03/31/2022] [Indexed: 11/21/2022] Open
Abstract
Cdc2-like kinase 4 (CLK4) inhibitors are of potential therapeutic value in many diseases particularly cancer. In this study, we combined extensive ligand-based pharmacophore exploration, ligand–receptor contact fingerprints generated by flexible docking, physicochemical descriptors and machine learning-quantitative structure–activity relationship (ML-QSAR) analysis to investigate the pharmacophoric/binding requirements for potent CLK4 antagonists. Several ML methods were attempted to tie these properties with anti-CLK4 bioactivities including multiple linear regression (MLR), random forests (RF), extreme gradient boosting (XGBoost), probabilistic neural network (PNN), and support vector regression (SVR). A genetic function algorithm (GFA) was combined with each method for feature selection. Eventually, GFA-SVR was found to produce the best self-consistent and predictive model. The model selected three pharmacophores, three ligand–receptor contacts and two physicochemical descriptors. The GFA-SVR model and associated pharmacophore models were used to screen the National Cancer Institute (NCI) structural database for novel CLK4 antagonists. Three potent hits were identified with the best one showing an anti-CLK4 IC50 value of 57 nM. Ligand-based pharmacophores, ligand–receptor contact fingerprints, physicochemical descriptors and machine learning were combined to probe binding of potent CLK4 antagonists. GFA-SVR gave the best model. Virtual screening identified 3 nanomolar hits.![]()
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Affiliation(s)
- Mai Fayiz Al-Tawil
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Jordan Amman 11942 Jordan
| | - Safa Daoud
- Department of Pharmaceutical Chemistry and Pharmacognosy, Faculty of Pharmacy, Applied Sciences Private University Amman Jordan
| | - Ma'mon M Hatmal
- Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, The Hashemite University PO Box 330127 Zarqa 13133 Jordan
| | - Mutasem Omar Taha
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Jordan Amman 11942 Jordan
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Saeed RM, Abdullah M, Ahram M, Taha MO. Novel Ellipsoid Chitosan-Phthalate Lecithin Nanoparticles for siRNA Delivery. Front Bioeng Biotechnol 2021; 9:695371. [PMID: 34395401 PMCID: PMC8355739 DOI: 10.3389/fbioe.2021.695371] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/15/2021] [Indexed: 12/11/2022] Open
Abstract
Small interfering RNA (siRNA) has received increased interest as a gene therapeutic agent. However, instability and lack of safe, affordable, and effective carrier systems limit siRNA's widespread clinical use. To tackle this issue, synthetic vectors such as liposomes and polymeric nanoparticles have recently been extensively investigated. In this study, we exploited the advantages of reduced cytotoxicity and enhanced cellular penetration of chitosan-phthalate (CSP) together with the merits of lecithin (LC)-based nanoparticles (NPs) to create novel, ellipsoid, non-cytotoxic, tripolyphosphate (TPP)-crosslinked NPs capable of delivering siRNA efficiently. The resulting NPs were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM), and were found to be ellipsoid in the shape of ca. 180 nm in size, exhibiting novel double-layer shells, with excellent stability at physiological pH and in serum solutions. MTT assay and confocal fluorescence microscopy showed that CSP-LC-TPP NPs are non-cytotoxic and efficiently penetrate cancer cells in vitro. They achieved 44% silencing against SLUG protein in MDA-MB-453 cancer cells and were significantly superior to a commercial liposome-based transfection agent that achieved only 30% silencing under comparable conditions. Moreover, the NPs protected their siRNA cargos in 50% serum and from being displaced by variable concentrations of heparin. In fact, CSP-LC-TPP NPs achieved 26% transfection efficiency in serum containing cell culture media. Real-time wide-field fluorescence microscopy showed siRNA-loaded CSP-LC-TPP NPs to successfully release their cargo intracellularly. We found that the amphoteric nature of chitosan-phthalate polymer promotes the endosomal escape of siRNA and improves the silencing efficiency.
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Affiliation(s)
- Ramzi Mukred Saeed
- Department of Pharmaceutical Sciences, School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Mohammed Abdullah
- Department of Physiology and Biochemistry, School of Medicine, The University of Jordan, Amman, Jordan
| | - Mamoun Ahram
- Department of Physiology and Biochemistry, School of Medicine, The University of Jordan, Amman, Jordan
| | - Mutasem Omar Taha
- Department of Pharmaceutical Sciences, School of Pharmacy, The University of Jordan, Amman, Jordan
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Taha MO, de Oliveira JV, Dias Borges M, de Lucca Melo F, Gualtieri FG, E Silva Aidar AL, Pacheco RL, de Melo Alexandre E Silva T, Klajner RK, Iuamoto LR, Munhoz Torres L, Morais Mendes de Paula BJ, de Campos K, Oliveira-Junior IS, Fagundes DJ. L-Arginine Modulates Intestinal Inflammation in Rats Submitted to Mesenteric Ischemia-Reperfusion Injury. Transplant Proc 2017; 48:512-5. [PMID: 27109989 DOI: 10.1016/j.transproceed.2015.12.063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 11/30/2015] [Accepted: 12/29/2015] [Indexed: 10/21/2022]
Abstract
BACKGROUND The goal of this study was to investigate whether exogenous offer of L-arginine (LARG) modulates the gene expression of intestinal dysfunction caused by ischemia and reperfusion. METHODS Eighteen Wistar-EPM1 male rats (250-300 g) were anesthetized and subjected to laparotomy. The superior mesenteric vessels were exposed, and the rats were randomized into 3 groups (n = 6): the control group (CG), with no superior mesenteric artery interruption; the ischemia/reperfusion group (IRG), with 60 minutes of ischemia and 120 minutes of reperfusion and saline injections; and the L-arginine group (IRG + LARG), with L-arginine injected in the femoral vein 5 minutes before ischemia, 5 minutes after reperfusion, and after 55 minutes of reperfusion. The total RNA was extracted and purified from samples of the small intestine. The concentration of each total RNA sample was determined by using spectrophotometry. The first-strand complementary DNA (cDNA) was synthesized in equal amounts of cDNA and the Master Mix SYBR Green qPCR Mastermix (SABiosciences, a Qiagen Company, Frederick, Md). Amounts of cDNA and Master Mix SYBR Green qPCR Mastermix were distributed to each well of the polymerase chain reaction microarray plate containing the predispensed gene-specific primer sets for Bax and Bcl2. Each sample was evaluated in triplicate, and the Student t test was applied to validate the homogeneity of each gene expression reaction (P < .05). RESULTS The gene expression of Bax in IRG (+1.48) was significantly higher than in IRG-LARG (+9.69); the expression of Bcl2L1 in IRG (+1.01) was significantly higher than IRG-LARG (+22.89). CONCLUSIONS The apoptotic cell pathway of 2 protagonists showed that LARG improves the gene expression of anti-apoptotic Bcl2l1 (Bcl2-like 1) more than the pro-apoptotic Bax (Bcl2-associated X protein).
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Affiliation(s)
- M O Taha
- Surgical Techniques and Experimental Surgery Division, Surgery Department, São Paulo Federal University-UNIFESP, São Paulo-SP, Brazil
| | - J V de Oliveira
- Surgical Techniques and Experimental Surgery Division, Surgery Department, São Paulo Federal University-UNIFESP, São Paulo-SP, Brazil
| | - M Dias Borges
- Surgical Techniques and Experimental Surgery Division, Surgery Department, São Paulo Federal University-UNIFESP, São Paulo-SP, Brazil
| | - F de Lucca Melo
- Surgical Techniques and Experimental Surgery Division, Surgery Department, São Paulo Federal University-UNIFESP, São Paulo-SP, Brazil
| | - F G Gualtieri
- Surgical Techniques and Experimental Surgery Division, Surgery Department, São Paulo Federal University-UNIFESP, São Paulo-SP, Brazil
| | - A L E Silva Aidar
- Surgical Techniques and Experimental Surgery Division, Surgery Department, São Paulo Federal University-UNIFESP, São Paulo-SP, Brazil
| | - R L Pacheco
- Surgical Techniques and Experimental Surgery Division, Surgery Department, São Paulo Federal University-UNIFESP, São Paulo-SP, Brazil
| | | | - R K Klajner
- Universitary Center São Camilo, São Paulo-SP, Brazil
| | - L R Iuamoto
- University of São Paulo Medical School-USP, São Paulo-SP, Brazil
| | | | | | - K de Campos
- Medical School of University of Mogi, Mogi das Cruzes-SP, Brazil
| | - I S Oliveira-Junior
- Surgical Techniques and Experimental Surgery Division, Surgery Department, São Paulo Federal University-UNIFESP, São Paulo-SP, Brazil
| | - D J Fagundes
- Surgical Techniques and Experimental Surgery Division, Surgery Department, São Paulo Federal University-UNIFESP, São Paulo-SP, Brazil.
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Al-Nadaf AH, Taha MO, Aldal'in HK. Haloperidol inhibits Memapsin 2: innovation by docking simulation and in vitro assay. Pak J Pharm Sci 2015; 28:139-146. [PMID: 25553677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A number of drugs exhibit unexpected pharmacological effects related to their ability to bind more than one receptor in humans. Haloperidol a typical antipsychotic drug appeared in several reports to be used in schizophrenia patients in which the significant of Alzheimer's disease has been reduced. The etiology of the disease is characterized by aggregates of amyloid plaques, largely composed of amyloid-β peptide formed from the amyloid precursor protein cleaved by Memapsin 2. To investigate if haloperidol can bind to Memapsin 2 active site, an initial molecular docking was performed as a preliminary in-silico screening test followed by in vitro enzyme inhibition assay. Haloperidol was found to fit readily in Memapsin binding site with IC(50)value 250mM. Haloperidol can be considered as important lead or important target can be modified for more inhibitory activity, with the intention of protection or treatment for Alzheimer's disease.
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Affiliation(s)
- Afaf Hasan Al-Nadaf
- Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Applied Science University, Amman, Jordan
| | - Mutasem Omar Taha
- Drug Discovery Unit, Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Jordan, Amman, Jordan
| | - Hammad Khalifeh Aldal'in
- Department of Medical Support, Al-Balqa Applied University, Al-Karak University College, Al-Karak, Jordan
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Saurim R, Koike MK, Bonservizi WGS, Felix GAA, Silva SM, Taha MO, Montero EFS. Cardiac effect of ischemic preconditioning and heparin following intestinal ischemia and reperfusion in rats. Transplant Proc 2014; 46:1852-6. [PMID: 25131053 DOI: 10.1016/j.transproceed.2014.05.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
To study the role of heparin and ischemic preconditioning (IPC) in cardiac injury after intestinal ischemia (I) and reperfusion (R), 54 rats underwent 60 minutes of I, which was produced by occlusion of the superior mesenteric artery, and/or 120 minutes of R. The IPC group had the I procedure stimulation for 5 minutes and R for 10 minutes. The control group was subjected to sham surgery only, and the other groups were injected with saline solution (SS; 0.1 mL) or heparin (100 IU/kg) via the inferior cava vein 5 minutes before I and 5 minutes before R and 55 minutes after the R begins in I-R groups. In all animals, cardiac samples were stained with hematoxylin and eosin for optical microscopy analysis, and other sample was processed for lipid peroxidation determination. In I-R groups, both heparin and IPC showed significant protection compared to the SS group; conversely, in animals subjected only to I, no protection was observed. Moreover, when heparin was associated with IPC, I-R protection was compromised and the ischemic injury increased. Data showed that IPC and heparin attenuated cardiac dysfunction caused by intestinal I and I-R, but when used in association did not show beneficial effects.
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Affiliation(s)
- R Saurim
- Escola Paulista de Medicina, Federal University of São Paulo, Brazil
| | - M K Koike
- Laboratory of Clinical Emergencies (LIM 51), Brazil
| | - W G S Bonservizi
- Escola Paulista de Medicina, Federal University of São Paulo, Brazil
| | - G A A Felix
- Escola Paulista de Medicina, Federal University of São Paulo, Brazil
| | - S M Silva
- Escola Paulista de Medicina, Federal University of São Paulo, Brazil
| | - M O Taha
- Operative Technique and Experimental Surgery Division, Escola Paulista de Medicina, Federal University of São Paulo, Brazil
| | - E F S Montero
- Operative Technique and Experimental Surgery Division, Escola Paulista de Medicina, Federal University of São Paulo, Brazil; Laboratory of Surgical Physiopathology (LIM 62), Department of Surgery, University of São Paulo, Federal University of São Paulo, Brazil.
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Al-Otoum R, Abulateefeh SR, Taha MO. Preparation of novel ionotropically crosslinked beads based on alginate-terephthalic acid composites as potential controlled release matrices. Pharmazie 2014; 69:10-18. [PMID: 24601217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Ionotropically crosslinked alginate beads suffer generally from poor drug loading, poor stability in biorelevant media and hence fast (i.e. uncontrolled) drug release profiles. Therefore, the present work aims at addressing these drawbacks by enhancing the stability of these metal ion-crosslinked alginate complexes via the incorporation of terephthalic acid which is proposed to act as a bridging crosslinking aid. In addition to the effect of terephthalic acid, we investigated the effect of curing temperature (4, 25 and 40 degrees C) and curing cross-linking metal ions (zinc, calcium and aluminum) on the characteristics of the resulting beads, i.e., drug loading and release profiles. Methylene blue (MB) was used as loaded drug model. The resulting beads were chemically and physically probed using infrared spectroscopy and differential scanning calorimetry. Interestingly, all prepared alginate-terephthalate beads (i.e., cured with zinc, calcium and aluminum) illustrated higher MB loadings and accessed controlled release profiles compared to their corresponding terephthalate-free alginate counterparts. Calcium-crosslinked alginate-terephthalate beads illustrated enteric release behavior regardless of their curing temperature. On the other hand, zinc-crosslinked alginate-terephthalate beads accessed enteric-like release profiles when only cured at 40 degrees C. However, aluminum-crosslinked alginate-terephthalate beads yielded interesting zero order release profiles regardless of their curing temperatures.
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Affiliation(s)
- R Al-Otoum
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, The University of Jordan, Amman, Jordan
| | - S R Abulateefeh
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, The University of Jordan, Amman, Jordan
| | - M O Taha
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, The University of Jordan, Amman, Jordan
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Taha MO, Miranda-Ferreira R, Chang ACR, Rodrigues AM, Fonseca IS, Toral LB, Cardoso MR, Simões MJ, Oliveira-Junior IS, Monteiro HP, Fagundes DJ, Taha NSA, Caricati-Neto A. Effect of ischemic preconditioning on injuries caused by ischemia and reperfusion in rat intestine. Transplant Proc 2013; 44:2304-8. [PMID: 23026580 DOI: 10.1016/j.transproceed.2012.07.056] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To study whether ischemic preconditioning (IPC) attenuated intestinal dysfunction caused by ischemia (I) and reperfusion (R), rats were underwent 60 minutes of I which was produced by occlusion of the superior mesenteric artery, and/or 120 minutes R. The IPC group had the I procedure previously stimulated for 5 minutes and the R for 10 minutes. IPC and sham groups were injected with saline solution (SS) via the femoral vein 5 minutes before the I and R, and for R. After I or I/R, 2-cm jejunal segments were mounted in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy. Compared with the sham group, jejunal contractions were similar in the IPC + I and the IPC + I/R groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS groups, but not in the IPC groups. These results suggested that ischemic preconditioning attenuated intestinal dysfunction caused by I and I/R.
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Affiliation(s)
- M O Taha
- Department of Pharmacology, Federal University of São Paulo (UNIFESP), São Paulo, Brazil.
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Ghadie MM, Miranda-Ferreira R, Taha NSA, Maroso AS, Moreti RJZ, Andraus MP, Zempulski P, Monteiro HP, Simões MJ, Fagundes DJ, Caricati-Neto A, Taha MO. Study of heparin in intestinal ischemia and reperfusion in rats: morphologic and functional evaluation. Transplant Proc 2013; 44:2300-3. [PMID: 23026579 DOI: 10.1016/j.transproceed.2012.07.055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To study whether treatment with heparin (HEP) attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rats were treated with HEP (100 U/kg intravenously) or saline solution (SS) before I (60 min), which was produced by occlusion of the superior mesenteric artery, and R (120 min). After I or I/R, we mounted 2-cm jejunal segment in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl, using a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy. Compared with the sham group, jejunal contractions were similar in the I + HEP and the I/R + HEP groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS, but not in the I + HEP and the I/R + HEP cohorts. These results suggested that HEP attenuated intestinal dysfunction caused by I and I/R.
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Affiliation(s)
- M M Ghadie
- Department of Pharmacology, Federal University of São Paulo, São Paulo, Brazil
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Campos VF, Miranda-Ferreira R, Taha NSA, Teixeira GD, Souza WTI, Carmo CEF, Silva-Neto LA, Gomes IT, Monteiro HP, Montero EFS, Fagundes DJ, Caricati-Neto A, Taha MO. Atenolol to treat intestinal ischemia and reperfusion in rats. Transplant Proc 2013; 44:2313-6. [PMID: 23026582 DOI: 10.1016/j.transproceed.2012.07.058] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
To study whether treatment with the beta-blocker atenolol (AT) attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rats were treated with AT (1.5 mg · kg(-1), intravenously) or saline solution (SS) prior to I (60 minutes), which was produced by occlusion of the superior mesenteric artery, and/or R (120 minutes). After I or I/R, 2-cm jejunal segments were mounted in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy analysis. Compared to the sham group, jejunal contractions were similar in the I + AT and the I/R + AT groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS groups, but not in the I + AT and the I/R + AT. These results suggest that AT may attenuate intestinal dysfunction caused by I and I/R.
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Affiliation(s)
- V F Campos
- Departments of Pharmacology, Biochemistry, Morphology, and Surgery, Federal University of São Paulo, São Paulo, Brazil
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Taha MO, Miranda-Ferreira R, Fagundes DJ, Simões RS, Monteiro HP, Oliveira-Júnior IS, Oliveira IS, Soares KRM, Martins MCL, Monteiro HP, Balbino AT, Rodrigues FF, Arruda TB, Abrão MS, Jurkiewicz A, Caricati-Neto A. Effects of 5'-adenosine triphosphate on intestinal ischemia-reperfusion in rabbits. Transplant Proc 2010; 42:461-4. [PMID: 20304165 DOI: 10.1016/j.transproceed.2010.01.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To study whether treatment with 5'-adenosine triphosphate (ATP), an agonist of P2 purine receptors, attenuated intestinal dysfunction caused by ischemia (I) and/or reperfusion (R), rabbits were treated with ATP (15 mgxkg(-1), intravenously) or saline solution (SS) 60 minutes before I by occlusion of the superior mesenteric artery and/or R (120 minutes). After I or I/R isolated 2-cm jejunal segments were mounted in an organ bath to study nerve-mediated contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained (hematoxylin and eosin) for optical microscopy. Compared to a sham group, the jejunal contractions were similar to sham hosts among I + ATP, but reduced in I + SS, I/R + SS, and I/R + ATP groups. The jejunal-enteric nerves were damaged in I + SS, I/R + SS, and I/R + ATP, but not the I + ATP group. These results suggested that ATP attenuated intestinal dysfunction produced by I, but not that caused by R.
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Affiliation(s)
- M O Taha
- Department of Pharmacoloy, Federal University São Paulo (UNIFESP), Brazil.
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15
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Taha MO, Miranda-Ferreira R, Paez RP, Simões RS, Boin HC, Martins IA, Versage PFV, Silva HFM, Penzo LDPRS, Fagundes ALN, Oliveira I, Caricati-Neto A, Monteiro HP. Role of L-arginine, a substrate of nitric oxide biosynthesis, on intestinal ischemia-reperfusion in rabbits. Transplant Proc 2010; 42:448-50. [PMID: 20304161 DOI: 10.1016/j.transproceed.2010.01.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
To study whether treatment with L-arginine (ARG), a substrate of nitric oxide biosynthesis, attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rabbits treated with ARG (100 mgxkg(-1), intravenously) or saline solution (SS) prior to I (60 minutes) by occlusion of superior mesenteric artery and/or during R (120 minutes). After I or I/R, 2-cm jejunal segments were isolated and mounted in an organ bath to study of neurogenic contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained (hematoxylin and eosin) for analysis by optical microscopy. Compared to the sham group, jejunal contractions were similar in I + ARG, but reduced in I + SS, I/R + SS, and I/R + ARG groups. The jejunal enteric nerves were damaged in I + SS, I/R + SS, and I/R + ARG, but not in I + ARG group, suggesting that ARG can attenuate intestinal dysfunctions due to I, but not to R.
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Affiliation(s)
- M O Taha
- Department of Pharmacoloy, Federal University of São Paulo (UNIFESP)/Escola Paulista de Medicina, São Paulo, Brazil.
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16
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Bustanji Y, Al-Masri IM, Qasem A, Al-Bakri AG, Taha MO. In silico screening for non-nucleoside HIV-1 reverse transcriptase inhibitors using physicochemical filters and high-throughput docking followed by in vitro evaluation. Chem Biol Drug Des 2009; 74:258-65. [PMID: 19703027 DOI: 10.1111/j.1747-0285.2009.00852.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reverse transcriptase, being the pivot in human immunodeficiency virus replication, is one of the most attractive targets for the development of new antiretroviral agents. We applied a virtual screening workflow based on a combination of physicochemical filters with high-throughput rigid molecular docking to discover novel efficient lead scaffolds for human immunodeficiency virus type 1 reverse transcriptase inhibition. In our protocol, different filters were employed to enrich the lead-likeness and improve the ligands efficiency of the filtered compounds. Out of the 238,819 compounds included in the National Cancer Institute database, 500 virtual screening hits were retrieved employing FILTER and FRED (molecular docking engine) softwares. Four compounds from the 20 highest ranking scored hits tested positive in human immunodeficiency virus type 1 reverse transcriptase using non-radioactive colorimetric assay method. These results demonstrate that our virtual screening protocol is able to enrich novel scaffolds for human immunodeficiency virus type 1 reverse transcriptase inhibition that could be useful for drug development in the area of acquired immune-deficiency syndrome treatment.
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Affiliation(s)
- Yasser Bustanji
- Faculty of Pharmacy, University of Jordan, 11942 Amman, Jordan.
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17
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Qunaibi EA, Disi AM, Taha MO. Phenytoin enhances collagenization in excision wounds and tensile strength in incision wounds. Pharmazie 2009; 64:584-586. [PMID: 19827299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
BACKGROUND Hard-to-heal wounds present a major medical problem. The anticonvulsant drug phenytoin has been shown to have prohealing effects in various types of wounds. In this study we evaluated the effect of phenytoin on some phases of wound healing in a rat excision wound model. METHODS A total of 98 adult male Wistar rats were used in this study. The effect of phenytoin ointment on the time for complete wound closure, as well as its biochemical and histological effects were evaluated in an excision wound. In addition, mechanical effect of phenytoin was evaluated in an incision wound rat model. RESULTS Phenytoin hastened the healing and increased protein and hydroxyproline contents as well as histological collagenization of excision wounds. In addition, it increased the tensile strength in incision wound model. CONCLUSION This study is the first to profile in detail the effects of phenytoin on morphology and biochemistry of excision wounds. We have shown that phenytoin not only shortens the time for wound healing but also improves the quality of the healing tissue. These effects are sought for in various clinical settings in which unaided healing is inconveniently prolonged or where the forming scar is not fully developed, allowing relapse of the wound.
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Affiliation(s)
- E A Qunaibi
- Department of Clinical Pharmacy and Therapeutics, Faculty of Pharmacy, Applied Sciences University, Amman, Jordan.
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18
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Taha MO, Simões MJ, Mendonça MV, Lugo FRC, Carmo-Filho R, Lazarini JL, Bessa MZ, Marconi TD, Magalhães KG, Soares JH, Tersariol ILS, Monteiro HP, Oliveira-Júnior IS, Oliveira I, Jurkiewicz A, Caricati-Neto A. Role of purines on hepatic ischemia-reperfusion lesions in rabbit. Transplant Proc 2009; 41:807-11. [PMID: 19376358 DOI: 10.1016/j.transproceed.2009.01.057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In this work, we evaluate the effects of adenosine 5' triphosphate (ATP) on hepatic lesions caused by ischemia/reperfusion (I/R) in liver rabbit. Rabbits were pretreated with ATP (15 mg/kg IV) or saline solution 0.9% (SS), before the hepatic I/R procedure. We evaluated the effects of ATP on hepatic injury before and after I/R. The warm hepatic I/R procedure caused profound acute liver injury, as indicated by elevated serum aspartate aminotransferase, alanine aminotransferase, and lactic dehydrogenase levels, as well as a high apoptotic cell count. All these changes were attenuate by ATP treatment before the hepatic I/R procedure. These results suggested that ATP exerted protective effects on hepatic I/R lesions in the rabbit. This ATP effect may be related to improved energy metabolism during reperfusion in ischemic livers protecting against functional damage of cellular and subcellular membranes during lipid peroxidation.
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Affiliation(s)
- M O Taha
- Department of Surgery, Federal University of São Paulo, Escola Paulista de Medicina, São Paulo, Brazil.
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19
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Taha MO, Gonçalves PFZRA, Vidigal ROG, Sacchi GPS, Pinheiro FG, Brandão LSG, Feguri S, Moraes-Filho AM, Ghadie MM, Magalhães KG, Simões MJ, Tersariol ILS, Monteiro HP, Oliveira-Júnior IS, Oliveira I, Jurkiewicz A, Caricati-Neto A. Protective effects of heparin on hepatic ischemia and reperfusion lesions in rabbits. Transplant Proc 2009; 41:812-5. [PMID: 19376359 DOI: 10.1016/j.transproceed.2009.02.042] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Because the role of heparin (HEP) in hepatic ischemia/reperfusion (I/R) injury is still not fully understood, we investigated the effects of treatment with HEP on hepatic I/R injury in rabbits. For I/R procedures, the portal vein and hepatic artery were occluded by a metallic clamp to promote ischemia. The clamp was removed after 30 minutes to allow reperfusion. Rabbits undergoing the I/R procedure were treated with HEP (100 U/kg) or saline solution 0.9% (SS). When compared with levels before I/R, the serum aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase, levels were increased by the hepatic I/R procedure, among rabbits treated with SS or HEP. However, the increase in these enzymes was lower among rabbits treated with HEP. Histologic analysis of hepatic tissue of rabbits undergoing I/R and treated with SS showed marked lesions in the central lobule with significant inflammatory infiltration. In contrast, a significant reduction in lesions caused by I/R was observed in the livers of rabbits treated with HEP. After starting reperfusion, we visualized apoptotic cells with nuclear staining among rabbits submitted to I/R and treated with SS, but not those treated with HEP. These results suggested that HEP was able to attenuate hepatic lesions caused by I/R in the livers of rabbits.
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Affiliation(s)
- M O Taha
- Department of Surgery, Federal University of São Paulo, Escola Paulista de Medicina, São Paulo, Brazil.
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Guimarães FAG, Taha MO, Fagundes DJ, Simões RS, Simões MJ, Caricati-Neto A. Heparin and hyperbaric oxygenation in enteric autonomic neuron preservation for transplant. Transplant Proc 2009; 41:824-6. [PMID: 19376362 DOI: 10.1016/j.transproceed.2009.02.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
BACKGROUND Previous studies have suggested that the addition of heparin to a preservation solution attenuated the autonomic dysfunction observed in rat jejunum and in addition that hypothermic hyperbaric oxygenation may play a role as a preservation technique. However, these studies did not address the lesion indices of the autonomic enteric neurons. We sought to investigate whether the autonomic enteric neurons are injured during cold ischemic preservation and whether administration of heparin or hyperbaric oxygenation prevents this lesion. METHODS Jejunal segments (2 cm; n = 20) of Wistar rats (12-16 weeks old) were maintained in lactated Ringer's solution without or with heparin (H- and H+, respectively) at 4 degrees C under normobaric conditions. Other jejunal segments (n = 10) were maintained at 4 degrees C in H- under hyperbaric oxygenation conditions (HBO). After preservation for 12 hours, H-, H+, and HBO preparations fixed in 10% formaldehyde were stained with hematoxylin and eosin. The lesion indices were expressed as the mean number of affected neurons (karyorhexis, nuclear dislocation, cytoplasmic vacuolisation) per 100 neurons present in intramural ganglia. Statistical analysis was performed using the Mann-Whitney test (P < .05). RESULTS The histologic studies showed that enteric autonomic neurons were damaged in H- jejunal segments. The lesion indices observed were: karyorhexis 90/100, nuclear dislocation 85/100, and cytoplasmic vacuolization 82/100. The autonomic neurons in H+ and HBO segments seemed to be normal and significantly well-preserved (P < .001). CONCLUSION Hypothermic hyperbaric oxygenation and heparin prevented lesions in cold ischemic preservation of enteric autonomic neurons.
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Affiliation(s)
- F A G Guimarães
- Departments of Science and Tecnology, Universidade Santa Cecília (UNISANTA), Santos, Brazil.
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Bustanji Y, Taha MO, Al-masri IM, Mohammad MK. Docking Simulations and in Vitro Assay Unveil Potent Inhibitory Action of Papaverine against Protein Tyrosine Phosphatase 1B. Biol Pharm Bull 2009; 32:640-5. [DOI: 10.1248/bpb.32.640] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Yasser Bustanji
- Faculty of Pharmacy, University of Jordan
- Faculty of Pharmacy, Applied Science Private University
| | | | - Ihab Mustafa Al-masri
- Faculty of Pharmacy, Applied Science Private University
- Faculty of Pharmacy, Al-Azhar University
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22
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Taha MO, Fraga MM, Guimarães FA, Jurkiewicz A, Caricati-Neto A. Atenolol Attenuates Autonomic Dysfunction of Rat Jejunum Submitted to Cold Ischemic Preservation. Transplant Proc 2006; 38:1784-8. [PMID: 16908280 DOI: 10.1016/j.transproceed.2006.05.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
In vitro studies have demonstrated that cold ischemic preservation (CIP) employed in small bowel transplantation produces loss of intestinal motility due to severe lesions of autonomic enteric nerves and that this autonomic dysfunction is attenuated by antioxidant agents. In this work, we investigated whether preservation with atenolol attenuated autonomic dysfunction of rat jejunum submitted to long-term CIP. Jejunal segments (2 cm) of Wistar rats (12 to 16 weeks old) were surgically isolated and preserved at 4 degrees C in Ringer's lactate solution without (-) or with (+) 1 mumol/L atenolol (AT). After preservation for 12 hours, AT+ and AT- preparations were mounted in parallel in isolated organ baths containing 10 mL Tyrode's solution at 37 degrees C for the study of neurogenic contractions evoked by electrical field stimulation (EFS; 10 to 30 Hz, 1-ms duration, 60 V) or by stimulation with nicotinic (nicotine, NIC) or muscarinic (carbachol, CCh) cholinoceptor agents as well as nicotine (hexamethonium, HEX) and muscarinic (atropine, ATR) antagonists. Contractions induced by EFS (30 Hz) were 46% higher in AT+ (0.38 +/- 0.02 g) than AT- (0.26 +/- 0.01 g), while contractions induced by NIC (1 mmol/L) were 84% higher in AT+ (0.46 +/- 0.03 g) than in AT- (0.25 +/- 0.02 g). In addition, contractions induced by CCh (1 mmol/L) were 34% higher in AT+ (0.87 +/- 0.06 g) than in AT- (0.65 +/- 0.08 g). EFS-, NIC-, and CCh-induced contractions were inhibited by pretreatment of jejunum with HEX or ATR (1 mumol/30 min), in AT+ and AT-. These results suggest that addition of atenolol in the preservation solution attenuated autonomic dysfunction of rat jejunum submitted to long-term CIP.
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Affiliation(s)
- M O Taha
- Department of Surgery, Federal University of São Paulo, Escola Paulista de Medicina, Rua Botucatu 740, CEP 04023-900 São Paulo-SP, Brazil.
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Guimarães FAG, Taha MO, Simões MJ, Moino CAA, Santos IV, Amador JC, Santos RA, Queiroz RB, Amaro RR, Jesus MAS, Caricati-Neto A. Use of Hyperbaric Oxygenation in Small Bowel Preservation for Transplant. Transplant Proc 2006; 38:1796-9. [PMID: 16908284 DOI: 10.1016/j.transproceed.2006.05.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
INTRODUCTION The aim of this work was to study the effects of hyperbaric oxygenation as a preservation technique for small bowel transplantation. METHODS Twenty 2-month-old male Wistar rats weighting 250 g were divided into two groups: group A (n = 10) in which the small bowel was preserved for 12 hours, and group B (n = 10) in which the small bowel was preserved for 24 hours. After vascular and intraluminal perfusion, 3-cm segments were maintained in Ringer's solution at temperatures between 2 degrees C to 4 degrees C and in normobaric O2 conditions (groups A1, B1) or conditioned in an hyperbaric O2 metal chamber (100% oxygen at 5.5 absolute atmospheres) (groups A2, B2). After this preservation time, we studied intestinal tissue injury and morphometric analysis of the villi. RESULTS Mucosal injury was significantly greater among group A1 compared to group A2 animals. The grade of the lesions was greater among group B1 compared to group B2 animals. Group A1 showed no difference from Group B1. For lesion grade, the range was smaller in group A2 and group B2 animals. The villi height was significantly smaller in groups A1 and B1 compared to the other groups; whereas it was higher in group A2 as compared with B2. CONCLUSION Hyperbaric oxygenation may play a role as a preservation technique. Further research is necessary.
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Affiliation(s)
- F A G Guimarães
- Department of Surgery, Universidade Federal de São Paulo/Escola Paulista de Medicina (UNIFESP-EPM), Rua Botucatu 740, CEP 04023-900 São Paulo-SP, Brazil.
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Guimarães FAG, Taha MO, Simões MJ, Moino CAA, Santos IV, Amador JC, Santos RA, Queiroz RB, Amaro RR, Jesus MAS. A Novel System for Organ and Tissues Preservation: The Refrigerating Hyperbaric Chamber. Transplant Proc 2006; 38:1879-82. [PMID: 16908312 DOI: 10.1016/j.transproceed.2006.06.054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
UNLABELLED This study was designed to investigate the feasibility of building a simple and inexpensive device to preserve organs or tissues in hyperbaric and hypothermic conditions. METHODS The device was built on a 40-cm wide, 28-cm long, and 23-cm deep stainless steel chassis. The pressure vessel was built by a 7.8-cm bore stainless steel cylinder put inside another 12-cm cylinder welded together and closed by a steel plate on the top and bottom. The inferior plate was welded, and the superior one was fixed by manual clasp nut. The cooling system is made up of air compressor, condenser, expansion area, and cooling worm that is located between the cylinders. The temperature-controlling device is a computer processor contained in an integrated-circuit chip, with a on-off system to maintain the chamber temperature between 2 degrees to 4 degrees C. The compression of the chamber is performed by lateral coupling with the oxygen cylinder and is maintained at 5.5 absolute atmospheres and controlled by air pressure gauge. The maximal work pressure was evaluated by spreadsheet. Temperature or pressure changes were evaluated by 12- and 24-hour assays. RESULTS The maximal work pressure permitted was 6.5 absolute atmospheres. Thus, the container was free from danger. The temperature inside the chamber was kept between 2 degrees and 4 degrees C. The production costs of the prototype was US$1000. DISCUSSION The manufacture of the refrigerating hyperbaric chamber is viable, simple, and inexpensive.
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Affiliation(s)
- F A G Guimarães
- Department of Surgery, Universidade Federal de São Paulo/Escola Paulista de Medicina (UNIFESP-EPM), Rua Botucatu 740, CEP 04023-900 São Paulo-SP, Brazil.
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Guimarães FAG, Taha MO, Simões MJ, Moino CAA, Santos IV, Amador JC, Santos RA, Queiroz RB, Amaro RR, Jesus MAS. Apoptosis and Nuclear Proliferation in Rat Small Bowel Submitted to Hypothermic Hyperbaric Oxygenation for Preservation. Transplant Proc 2006; 38:1876-8. [PMID: 16908311 DOI: 10.1016/j.transproceed.2006.06.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
UNLABELLED This study was conducted to assess apoptosis and nuclear proliferation in rat small bowel submitted to hypothermic hyperbaric oxygenation for preservation. METHODS Twenty two-month-old, male Wistar rats, weighing 250 g were divided into two groups: group I (n = 10), in which the small bowel was preserved for 12 hours, and group II (n = 10) in which the small bowel was preserved for 24 hours. After vascular and intraluminal perfusion, 3-cm segments were maintained in Ringer's solution at 2 degrees to 4 degrees C under normobaric conditions (groups Ia and IIa) or conditioned in a small hyperbaric metal chamber with 100% oxygen at 5.5 absolute atmospheres (groups Ib and IIb). After 12 or 24 hours, apoptotic and mitotic indices were evaluated by immunohistochemical methods. RESULTS The apoptotic index was significantly higher in small bowel segments in groups Ia and IIa compared with groups Ib and IIb. The mitotic index was significantly higher among group IIb. CONCLUSION Hypothermic hyperbaric oxygenation reduced intestinal epithelial apoptosis and increased nuclear proliferation during rat small bowel preservation.
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Affiliation(s)
- F A G Guimarães
- Department of Surgery, Universidade Federal de São Paulo/Escola Paulista de Medicina (UNIFESP-EPM), Rua Botucatu 740, CEP 04023-900 São Paulo-SP, Brazil.
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26
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Taha MO, Fraga MM, Guimarães FA, Jurkiewicz A, Caricati-Neto A. Autonomic Dysfunction of Rat Jejunum Submitted to Cold Ischemic Preservation Is Prevented by Heparin. Transplant Proc 2006; 38:1779-83. [PMID: 16908279 DOI: 10.1016/j.transproceed.2006.05.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Previous studies suggest that cold ischemic preservation (CIP) employed in small bowel transplantation promotes loss of intestinal motility due to severe lesions in autonomic enteric nerves. This autonomic dysfunction may be prevented by antioxidant agents. In this work, we investigated whether preservation with heparin prevented autonomic dysfunction of rat jejunum submitted to CIP for a long time. Jejunal segments (2 cm) of Wistar rats (12 to 16 weeks old) were preserved at 4 degrees C in Ringer's lactate solution without (-) or with (+) 100 UI/mL heparin (H). After preservation for 12 hours, H+ and H- preparations were mounted in parallel in isolated organ baths containing 10 mL Tyrode's solution at 37 degrees C for the study of neurogenic contractions evoked by electrical field stimulation (EFS; 10-30 Hz, 1-ms duration, 60 V) or by stimulation of nicotinic (NIC) or muscarinic (carbachol, CCh) cholinoceptors. The effects of NIC (hexamethonium, HEX) and muscarinic (atropine, ATR) antagonists were studied on these contractions. Contractions induced by EFS (30 Hz) were four times greater in H+ (1.02 +/- 0.12 g) versus H- (0.26 +/- 0.07 g), while contractions induced by NIC (1 mmol/L) were also four times higher in H+ (1.07 +/- 0.10 g) than H- (0.25 +/- 0.09 g) preparations. In addition, contractions induced by CCh (1 mmol/L) were two times higher in H+ (1.21 +/- 0.13 g) than in H- (0.65 +/- 0.10 g). EFS, NIC, and CCh contractions were inhibited by pretreatment of jejunum with HEX or ATR (1 mumol/L/30 min), in H+ and H-. These results indicated that addition of heparin to a preservation solution attenuated the autonomic dysfunction of rat jejunum submitted to CIP for a long time.
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Affiliation(s)
- M O Taha
- Department of Surgery, Federal University of São Paulo, Escola Paulista de Medicina, Rua Botucatu 740, CEP 04023-900 São Paulo-SP, Brazil.
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Aiedeh KM, Khatib HA, Taha MO, Al-Zoubi N. Application of novel chitosan derivatives in dissolution enhancement of a poorly water soluble drug. Pharmazie 2006; 61:306-11. [PMID: 16649543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Solid dispersions of the poorly water soluble drug dexamethasone and newly synthesized chitosan derivatives (chitosan succinate, CS, and chitosan phthalate, CP) were prepared by spray drying. The resulting microspheres were evaluated in terms of their drug loading or encapsulation efficiency as well as drug release profile. Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD) and infrared spectroscopy (IR) were used to evaluate the solid dispersion for possible interactions between drug and polymers. The pure drug was evaluated in the same manner for comparison purposes. High loading levels (>74%) were achieved using CP and CS as polymer matrices. Drug release rate was accelerated significantly upon the formation of the solid dispersions; the drug release rate was increased with increasing percentage of the chitosan derivatives in the microspheres. IR studies showed no chemical interaction while the X-ray studies showed a significant change in the crystallinity of the drug upon formation of solid dispersions.
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Affiliation(s)
- K M Aiedeh
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, University of Jordan, Amman, Jordan.
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Taha MO, Aiedeh KM, Al-Hiari Y, Al-Khatib H. Synthesis of zinc-crosslinked thiolated alginic acid beads and their in vitro evaluation as potential enteric delivery system with folic acid as model drug. Pharmazie 2005; 60:736-42. [PMID: 16259119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The aim of this study is to explore the potential of synthetic modifications of alginic acid as a method to enhance the stability of its complexes with divalent cations under physiological conditions. A fraction of algin's carboxylic acid moieties was substituted with thiol groups to different substitution degrees through conjugating alginate to cysteine to produce alginate-cysteine (AC) conjugates. Infrared spectrophotometry and iodometry were used to characterize the resulting polymeric conjugates in terms of structure and degree of substitution. Moreover, zinc ions were used to crosslink the resulting AC polymers. Folic acid loaded beads were prepared from Zinc-crosslinked AC polymers (AC-Zn) of different cysteine substitution degrees. The generated beads were then investigated in vitro for their capacity to modify folic acid release. AC-Zn polymeric beads resisted drug release under acidic conditions (pH 1.0). However, upon transfer to a phosphate buffer solution (pH 7.0) they released most of their contents almost immediately. This change in drug release behavior is most probably due to the sequestering of zinc cations by phosphate ions within the buffer solution to form insoluble chelates and, to a lesser extent, the ionization of the carboxylic acid and thiol moieties. Removal of zinc ions from the polymeric matrix seems to promote polymeric disintegration and subsequent drug release. A similar behavior is expected in vivo due to the presence of natural zinc sequestering agents in the intestinal fluids. AC-Zn polymers provided a novel approach for enteric drug delivery as drug release from these matrices complied with the USP specifications for enteric dosage forms.
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Affiliation(s)
- M O Taha
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Jordan, Amman, Jordan.
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Taha M, Soares J, Venerando P, Gandolfi A, Tsuchya J, Caricati-neto A, Poli de Figueiredo L. Crit Care 2005; 9:P122. [DOI: 10.1186/cc3666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Taha MO, Carvalho CA, Souza HS, Fagundes DJ, Simões MJ, Novo NF, Caricati-Neto A. Cytoprotective effects of alpha-tocopherol on ischemia/reperfusion injury in rat liver: biochemical and histological evaluation. Transplant Proc 2004; 36:276-82. [PMID: 15050133 DOI: 10.1016/j.transproceed.2004.01.076] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- M O Taha
- Surgery Department, Säo Paulo, Brazil.
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Hamdan II, Afifi F, Taha MO. In vitro alpha amylase inhibitory effect of some clinically-used drugs. Pharmazie 2004; 59:799-801. [PMID: 15544061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Twenty six medicinal compounds used for treating various diseases and representing different chemical and pharmacological classes were tested for their potential alpha amylase inhibitory activity in vitro. Three of these (tetracycline, enalapril and captopril) were found to have a substantial alpha amylase inhibitory activity. The effect was shown to be dose dependent and the IC50 was determined (tetracycline = 0.59 mM, enalapril = 0.29 mM, and captopril = 0.78 mM) and compared to that of acarbose (0.0062 = mM). The potential pharmacological implications of this effect are discussed.
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Affiliation(s)
- I I Hamdan
- Department of Pharmaceutical Sciences, University of Jordan, Amman, Jordan.
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Taha MO, Fraga MM, Fagundes DJ, Jurkiewicz A, Caricati-Neto A. Effect of allopurinol on autonomic dysfunction in rat jejunal segments exposed to cold ischemic preservation for transplantation. Transplant Proc 2004; 36:293-5. [PMID: 15050137 DOI: 10.1016/j.transproceed.2004.01.095] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- M O Taha
- Department of Surgery, Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM), São Paulo, Brazil.
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Taha MO, Mueller SF, Fraga MM, Rosseto M, Fagundes DJ, Juliano Y, Caricati-Neto A. Morphologic analysis of the fibular nerve repaired with fibrin adhesive. Transplant Proc 2004; 36:401-3. [PMID: 15050173 DOI: 10.1016/j.transproceed.2004.01.102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- M O Taha
- Department of Surgery, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil.
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Taha MO, Ribeiro EB, Sardinha FLC, Fraga MM, Fagundes DJ, Caricati-Neto A. Interposition of a distal colon segment following 80% jejunum-ileal resection: evaluation of glucose absorption in rats. Transplant Proc 2004; 36:370-2. [PMID: 15050162 DOI: 10.1016/j.transproceed.2004.01.101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- M O Taha
- Department of Surgery, Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM), São Paulo, Brazil.
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Taha MO, Fraga MM, Fagundes DJ, Jurkiewicz A, Caricati-Neto A. Ascorbic acid prevents autonomic dysfunction in rat jejunal submitted to cold ischemic preservation for transplantation. Transplant Proc 2004; 36:289-92. [PMID: 15050136 DOI: 10.1016/j.transproceed.2004.01.077] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- M O Taha
- Surgery Department, Universidade Federal de São Paulo - Escola Paulista de Medicina, São Paulo-SP, Brazil.
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36
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Taha MO, Souza HS, Carvalho CA, Fagundes DJ, Simões MJ, Novo NF, Caricati-Neto A. Cytoprotective effects of ascorbic acid on the ischemia-reperfusion injury of rat liver. Transplant Proc 2004; 36:296-300. [PMID: 15050138 DOI: 10.1016/j.transproceed.2004.01.096] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- M O Taha
- Department of Surgery, Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM), São Paulo, Brazil.
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Taha MO, Rosseto M, Fraga MM, Mueller SF, Fagundes DJ, Novo NF, Caricati-Neto A. Effect of retinoic acid on tibial nerve regeneration after anastomosis in rats: histological and functional analyses. Transplant Proc 2004; 36:404-8. [PMID: 15050174 DOI: 10.1016/j.transproceed.2004.01.100] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- M O Taha
- Department of Surgery, Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM), São Paulo, Brazil.
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Brandão SC, Taha MO, Fagundes DJ, Souccar C, Lapa AJ, da Silva Pias VM. Alpha-tocopherol in the hypothermic preservation of the rat small bowel: a functional study. Transplant Proc 2002; 34:1092-4. [PMID: 12072285 DOI: 10.1016/s0041-1345(02)02813-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- S C Brandão
- Department of Surgery, Federal University of Sao Paulo (UNIFESP), Sao Paulo, Brazil.
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Taha MO, Fraga MM, Fagundes DJ, Bandeira CP, Caricati-Neto A, Jurkiewicz A. Effect of preservation conditions on autonomic transmission in rat small bowel. Transplant Proc 2002; 34:1021-4. [PMID: 12034290 DOI: 10.1016/s0041-1345(02)02698-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- M O Taha
- Department of Surgery, Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina, São Paulo-SP, Brazil
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Guimarães FAG, Taha MO, Simões MJ, Fagundes DJ. Ischemia-reperfusion of the small intestine and hyperbaric oxygen treatment: a morphologic study in rats. Transplant Proc 2002; 34:977-9. [PMID: 12034268 DOI: 10.1016/s0041-1345(02)02726-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- F A G Guimarães
- Department of Surgery, Universidade Federal de Sāo Paulo-Escola Paulista de Medicina, Sāo Paulo, Brazil
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Aiedeh K, Taha MO. Synthesis of iron-crosslinked chitosan succinate and iron-crosslinked hydroxamated chitosan succinate and their in vitro evaluation as potential matrix materials for oral theophylline sustained-release beads. Eur J Pharm Sci 2001; 13:159-68. [PMID: 11297900 DOI: 10.1016/s0928-0987(00)00217-7] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chitosan succinate (CS) and hydroxamated chitosan succinate (HCS) were prepared. The generated semisynthetic polymers were employed in the formation of drug-loaded, iron(III)-crosslinked polymeric beads. Infrared spectroscopy was employed to prove the crosslinking. The produced beads were evaluated in vitro as drug prolonging and potentially orally administered delivery system. Theophylline was used as the loaded model drug. The generated beads proved to be successful in prolonging drug release. Iron leaching from the generated beads was minimal (<2%), and it only took place under acidic conditions (pH 1).
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Affiliation(s)
- K Aiedeh
- Department of Pharmaceutical Technology and Pharmaceutics, Faculty of Pharmacy, University of Jordan, Amman, Jordan.
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Taha MO, Ribeiro MA, de Oliveira Gomes P, Montero Frasson E, Plapler H, Ferreira R, Lapa AJ, Soucar C. Evaluation of the longitudinal musculature of segments of the distal colon interposed following extended jejunum-ileum resection. Microsurgery 2001; 19:306-10. [PMID: 10586192 DOI: 10.1002/(sici)1098-2752(1999)19:7<306::aid-micr2>3.0.co;2-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Several morbid conditions may necessitate extensive intestinal resection, leading to short-bowel syndrome. When clinical treatment becomes inefficient, a surgical approach is necessary. Distal colon interposition is one of the viable techniques. The interposition of colon segments between remnants of the small bowel improved lifestyle, increased transit time, and diminished diarrhea. The aim of this study is to observe the longitudinal muscular contractions after distal colon interposition. Sixteen male Wistar rats (EPM-1) were submitted to an 80% small bowel resection associated with a partial colectomy of the distal colon immediately after the bifurcation of the middle colic artery followed by a 3-cm isoperistaltic distal colon interposition. After 70 days, the animals were submitted to euthanasia and segments of the jejunum, ileum, remnant colon, and interposed colon were prepared for pharmacological tests. The isometric contractions were measured by a polygraph. After 30 minutes, the dose/effect curves were obtained for both metacholine and barium chloride stimulation through the extraluminal surface (serosa). After this period, we observed a significant increase in the length, diameter, and thickness of the intestinal wall. Regarding the sensibility (pD(2)), no difference was found (interposed colon = 7.21 +/- 0.2; remnant colon = 7.65 +/- 0.1; remnant jejunum 7.46 +/- 0.1; and remnant ileum 7.57 +/- 0.1), even though the animals were submitted to different procedures. In relation to the maximal effect (E(max)), the longitudinal muscle contraction responses (interposed colon = 11.79 +/- 0.1; remnant jejunum = 15.42 +/- 0.2; and remnant ileum = 11.48 +/- 0.2) were lower than those of the remnant colon (E(max) = 22.42 +/- 0.1). This means that there was a possible adaptation of colonic segments to their new location.
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Affiliation(s)
- M O Taha
- Department of Surgery, Discipline of Operative Technique and Experimental Surgery, Federal University of São Paulo, Escola Paulista de Medicina, São Paulo, Brazil
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Ribeiro MA, Montero EF, Piva AM, Gualberto E, Nigro AJ, Taha MO, Soucar C, Lapa AJ, Venco FE. Histopathologic changes in rat small intestine during storage in UW or celsior solution with or without a 21-aminosteroid (U74389G) after 12, 18, and 24 hours. Transplant Proc 2000; 32:1261-2. [PMID: 10995938 DOI: 10.1016/s0041-1345(00)01215-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- M A Ribeiro
- Department of Surgery, Division of Experimental Surgery, Federal University of São Paulo, Escola Paulista de Medicina, São Paulo, Brazil
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Taha MO, Aiedeh K. Synthesis of iron-crosslinked hydroxamated alginic acid and its in vitro evaluation as a potential matrix material for oral sustained-release beads. Pharmazie 2000; 55:663-7. [PMID: 11031769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Hydroxamated alginic acid (HAA) was prepared. The generated semisynthetic polymer was employed in the formation of drug-loaded, iron(III)-crosslinked polymeric beads. Infrared spectroscopy was employed to prove the crosslinking. The degree of hydroxamate substitution was determined by acid-base back titration, and it was found to be ca. 20%. The produced beads were evaluated in vitro as orally administered sustained release drug delivery system. Theophylline, paracetamol, and chlorpheniramine maleate were used as model drugs. The generated beads proved to be successful in prolonging drug release, particularly in the case of theophylline. Iron leaching from the generated beads was minimal (< 0.5% of the entire complexed iron), and took place during passage through the simulated gastric fluid.
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Affiliation(s)
- M O Taha
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Jordan, Amman, Jordan
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Aiedeh K, Taha MO. Synthesis of chitosan succinate and chitosan phthalate and their evaluation as suggested matrices in orally administered, colon-specific drug delivery systems. Arch Pharm (Weinheim) 1999; 332:103-7. [PMID: 10228455 DOI: 10.1002/(sici)1521-4184(19993)332:3<103::aid-ardp103>3.0.co;2-u] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The naturally occurring polymer chitosan was reacted separately with succinic and phthalic anhydrides. The resulting semisynthetic polymers were assessed as potential matrices for colon-specific, orally administered drug delivery. Sodium diclofenac was used as the dispersed model drug. The prepared matrices were incorporated into tablets, which were evaluated in vitro. The evaluation included dissolution studies conducted under simulated gastrointestinal conditions of pH and transit times. The percentage fluid uptake was used to indicate the ability of the matrix to protect an embedded drug from gastric juices. The prepared matrices resisted dissolution under acidic conditions. On the other hand, improved drug release profiles were observed under basic conditions. Therefore, the results suggest the suitability of the prepared matrices in colon specific, orally administered drug delivery system. However, future in vivo testing is planned to fully establish the suitability of the prepared polymers for colon-specific drug delivery.
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Affiliation(s)
- K Aiedeh
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, University of Jordan, Amman, Jordan
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Koh IH, Taha MO, Smaili SS, Ferreira RG, Goldenberg S, Jurkiewicz A. Evaluation of the intestinal mucosa barrier by a pharmacological approach. Transplant Proc 1994; 26:1663-4. [PMID: 8030079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- I H Koh
- Department of Surgery, Escola Paulista de Medicina, São Paulo, Brazil
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Taha MO, Jurkiewicz A, Smaili SS, Andrade P, Ferreira RG, Goldenberg S, Koh IH. Use of a functional pharmacological monitor in small bowel preservation. Transplant Proc 1994; 26:1489-90. [PMID: 8030003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- M O Taha
- Department of Surgery, Escola Paulista de Medicina, Técnica Operatória e Cirurgia Experimental, São Paulo, Brazil
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Alhendi H, Özer M, Taha MO. Asymptotic behavior of the Higgs coupling in SU(2) x U(1) theory. Phys Rev D Part Fields 1992; 46:428-430. [PMID: 10014773 DOI: 10.1103/physrevd.46.428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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