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Soares G, Pinto L, Liebl M, Biasotti G, Prospero A, Stoppa E, Bakuzis A, Baffa O, Wiekhorst F, Miranda JRA. Quantitative imaging of magnetic nanoparticles in an unshielded environment using a large AC susceptibility array. J Biol Eng 2022; 16:25. [PMID: 36221096 PMCID: PMC9552418 DOI: 10.1186/s13036-022-00305-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 09/26/2022] [Indexed: 11/29/2022] Open
Abstract
Background Non-invasive magnetic imaging techniques are necessary to assist magnetic nanoparticles in biomedical applications, mainly detecting their distribution inside the body. In Alternating Current Biosusceptometry (ACB), the magnetic nanoparticle's magnetization response under an oscillating magnetic field, which is applied through an excitation coil, is detected with a balanced detection coil system. Results We built a Multi-Channel ACB system (MC-ACB) containing nineteen pick-up coils and obtained 2D quantitative images of magnetic nanoparticle distributions by solving an inverse problem. We reconstructed the magnetic nanoparticles spatial distributions in a field of view of 14 × 14 cm2 with a spatial resolution of 2.0 cm and sensitivity in the milligram scale. A correlation coefficient between quantitative reconstructed and nominal magnetic nanoparticle distributions above 0.6 was found for all measurements. Conclusion Besides other interesting features such as sufficient large field of view dimension for mice and rat studies, portability, and the ability to assess the quantitative magnetic nanoparticles distributions in real-time, the MC-ACB system is a promising tool for quantitative imaging of magnetic nanoparticles distributions in real-time, offering an affordable setup for easy access in clinical or laboratory environments.
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Affiliation(s)
- Guilherme Soares
- Physikalisch-Technische Bundesanstalt, Abbestraße 2-12, 10587, Berlin, Germany. .,Biosciences Institute of Botucatu, São Paulo State University, Botucatu, São Paulo, 18618-689, Brazil.
| | - Leonardo Pinto
- Biosciences Institute of Botucatu, São Paulo State University, Botucatu, São Paulo, 18618-689, Brazil
| | - Maik Liebl
- Physikalisch-Technische Bundesanstalt, Abbestraße 2-12, 10587, Berlin, Germany
| | - Gabriel Biasotti
- Biosciences Institute of Botucatu, São Paulo State University, Botucatu, São Paulo, 18618-689, Brazil
| | - Andre Prospero
- Biosciences Institute of Botucatu, São Paulo State University, Botucatu, São Paulo, 18618-689, Brazil
| | - Erick Stoppa
- Biosciences Institute of Botucatu, São Paulo State University, Botucatu, São Paulo, 18618-689, Brazil
| | - Andris Bakuzis
- Institute of Physics, Federal University of Goiás, Goiânia, 74690-900, Brazil
| | - Oswaldo Baffa
- Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto, Sao Paulo, 14040-900, Brazil
| | - Frank Wiekhorst
- Physikalisch-Technische Bundesanstalt, Abbestraße 2-12, 10587, Berlin, Germany
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Bezerra AT, Pinto LA, Rodrigues DS, Bittencourt GN, Mancera PFDA, Miranda JRDA. Classification of gastric emptying and orocaecal transit through artificial neural networks. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2021; 18:9511-9524. [PMID: 34814356 DOI: 10.3934/mbe.2021467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Classical quantification of gastric emptying (GE) and orocaecal transit (OCT) based on half-life time T$ _{50} $, mean gastric emptying time (MGET), orocaecal transit time (OCTT) or mean caecum arrival time (MCAT) can lead to misconceptions when analyzing irregularly or noisy data. We show that this is the case for gastrointestinal transit of control and of diabetic rats. Addressing this limitation, we present an artificial neural network (ANN) as an alternative tool capable of discriminating between control and diabetic rats through GE and OCT analysis. Our data were obtained via biological experiments using the alternate current biosusceptometry (ACB) method. The GE results are quantified by T$ _{50} $ and MGET, while the OCT is quantified by OCTT and MCAT. Other than these classical metrics, we employ a supervised training to classify between control and diabetes groups, accessing sensitivity, specificity, $ f_1 $ score, and AUROC from the ANN. For GE, the ANN sensitivity is 88%, its specificity is 83%, and its $ f_1 $ score is 88%. For OCT, the ANN sensitivity is 100%, its specificity is 75%, and its $ f_1 $ score is 85%. The area under the receiver operator curve (AUROC) from both GE and OCT data is about 0.9 in both training and validation, while the AUCs for classical metrics are 0.8 or less. These results show that the supervised training and the binary classification of the ANN was successful. Classical metrics based on statistical moments and ROC curve analyses led to contradictions, but our ANN performs as a reliable tool to evaluate the complete profile of the curves, leading to a classification of similar curves that are barely distinguished using statistical moments or ROC curves. The reported ANN provides an alert that the use of classical metrics can lead to physiological misunderstandings in gastrointestinal transit processes. This ANN capability of discriminating diseases in GE and OCT processes can be further explored and tested in other applications.
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Affiliation(s)
- Anibal Thiago Bezerra
- Institute of Exact Sciences, Federal University of Alfenas-MG (UNIFAL-MG), Alfenas-MG 37133-840, Brazil
| | - Leonardo Antonio Pinto
- Institute of Biosciences, São Paulo State University (UNESP), Botucatu-SP 18618-689, Brazil
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The Influence of Omeprazole on the Dissolution Processes of pH-Dependent Magnetic Tablets Assessed by Pharmacomagnetography. Pharmaceutics 2021; 13:pharmaceutics13081274. [PMID: 34452233 PMCID: PMC8399305 DOI: 10.3390/pharmaceutics13081274] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 08/06/2021] [Accepted: 08/12/2021] [Indexed: 12/19/2022] Open
Abstract
Pharmacomagnetography involves the simultaneous assessment of solid dosage forms (SDFs) in the human gastrointestinal (GI) tract and the drug plasmatic concentration, using a biomagnetic technique and pharmacokinetics analysis. This multi-instrumental approach helps the evaluation, as GI variables can interfere with the drug delivery processes. This study aimed to employ pharmacomagnetography to evaluate the influence of omeprazole on the drug release and absorption of metronidazole administered orally in magnetic-coated tablets. Magnetic-coated tablets, coated with Eudragit® E-100 (E100) and containing 100 mg of metronidazole, were produced. For the in vivo experiments, 12 volunteers participated in the two phases of the study (placebo and omeprazole) on different days to assess the bioavailability of metronidazole. The results indicated a shift as the pH of the solution increased and a delay in the dissolution of metronidazole, showing that the pH increase interferes with the release processes of tablets coated with E100. Our study reinforced the advantages of pharmacomagnetography as a tool to perform a multi-instrumental correlation analysis of the disintegration process and the bioavailability of drugs.
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Preisig D, Varum F, Bravo R, Hartig C, Spleiss J, Abbes S, Caobelli F, Wild D, Puchkov M, Huwyler J, Haschke M. Colonic delivery of metronidazole-loaded capsules for local treatment of bacterial infections: A clinical pharmacoscintigraphy study. Eur J Pharm Biopharm 2021; 165:22-30. [PMID: 33971274 DOI: 10.1016/j.ejpb.2021.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/27/2021] [Accepted: 05/01/2021] [Indexed: 12/12/2022]
Abstract
Drug delivery to the colon offers great promise for local treatment of colonic diseases as it allows bypassing systemic absorption in the small intestine, thereby increasing luminal drug concentrations in the colon. The primary objective of this in vivo pharmaco-scintigraphy study was to assess the colon drug targeting accuracy of a metronidazole benzoate colonic drug delivery system intended for local treatment of Clostridioides difficile infections. Additionally, it was assessed if the concept of mucoadhesion would increase colonic residence time and promote higher drug bioavailability. Two different capsule formulations were designed and tested in healthy human subjects. Capsules contained either non-mucoadhesive (NM) or mucoadhesive (M) microgranules, both loaded with 100 mg metronidazole benzoate (antibiotic prodrug) and 5 mg samarium oxide (scintigraphy tracer). Filled capsules were coated with a colonic-targeting technology consisting of two functional layers, which allow for accelerated drug release mediated by the intestinal pH in combination with colonic bacteria. Coated capsules were neutron-activated to yield the radioisotope 153Sm prior to administration to 18 healthy subjects. Gamma-scintigraphy imaging was combined with the measurement of drug plasma levels. Formulation NM showed high colon-targeting accuracy. Initial capsule disintegration within the targeted ileocolonic region was observed in 8 out of 9 subjects (89%) with colonic arrival times in the range of 3.5-12 h and reduced systemic exposure. In contrast, the mucoadhesive formulation M showed some inconsistency regarding the site of initial capsule disintegration (targeting accuracy 56%). Variability of drug release was attributed to self-adhesion and agglomeration of the mucoadhesive microparticles within the capsule. Accurate ileocolonic delivery of metronidazole-loaded microgranules was achieved following oral administration of colonic-targeted capsules. Delayed drug release from NM microparticles in the colon leads to a reduced systemic exposure compared to immediate-release data from literature and presumably elevated drug concentrations in the colonic lumen. This approach offers promising options for the local treatment of colonic diseases.
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Affiliation(s)
- Daniel Preisig
- Department of Pharmaceutical Technology, University of Basel, Basel, Switzerland
| | | | | | | | | | - Sonia Abbes
- Tillotts Pharma AG, Rheinfelden, Switzerland
| | - Federico Caobelli
- Division of Nuclear Medicine, University Hospital Basel, Basel, Switzerland
| | - Damian Wild
- Division of Nuclear Medicine, University Hospital Basel, Basel, Switzerland
| | - Maxim Puchkov
- Department of Pharmaceutical Technology, University of Basel, Basel, Switzerland
| | - Jörg Huwyler
- Department of Pharmaceutical Technology, University of Basel, Basel, Switzerland.
| | - Manuel Haschke
- Clinical Pharmacology & Toxicology, University Hospital Basel, Basel, Switzerland
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Pinto LA, Corá LA, Rodrigues GS, Prospero AG, Soares GA, de Andreis U, de Arruda Miranda JR. Pharmacomagnetography to evaluate the performance of magnetic enteric-coated tablets in the human gastrointestinal tract. Eur J Pharm Biopharm 2021; 161:50-55. [PMID: 33592280 DOI: 10.1016/j.ejpb.2021.02.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 02/05/2021] [Accepted: 02/08/2021] [Indexed: 12/30/2022]
Abstract
A magnetic enteric-coated tablet containing diclofenac sodium was produced, and its performance under physiological and disturbed gastrointestinal motility was assessed through pharmacomagnetography analysis. In vitro studies were performed using conventional methods and in vivo studies were conducted on healthy volunteers before (control) and after domperidone administration. The magnetic tablet's gastrointestinal (GI) transit and disintegration process were monitored using the Alternating Current Biosusceptometry sensors combined with drug plasmatic concentration. The Gastric Residence Time, Colon Arrival Time, Small Bowel Transit Time, Disintegration Time and the pharmacokinetics parameters were calculated. The pH-dependent polymers used to coat the magnetic tablets were able to avoid the premature drug release on gastric or small intestine simulated medium. Gastric Residence Time was accelerated compared with the control group (p < 0.01). No significant differences were found regarding small bowel transit, colon arrival, disintegration process, or pharmacokinetics parameters. A strong correlation between magnetic monitoring and pharmacokinetics parameters analysis was determinant to evaluate the efficiency in the drug delivery at a specific site in the human gastrointestinal tract. In addition, a tablet with a damaged coating was used as a proof of concept to show the suitability of our methodology to evaluate the tablet. Our study showed that pharmacomagnetography is a multi-instrumental approach towards assessing drug delivery and bioavailability.
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Affiliation(s)
- Leonardo Antonio Pinto
- São Paulo State University - UNESP, Department of Biophysics and Pharmacology, Institute of Biosciences, Botucatu, São Paulo 18618-689, Brazil.
| | - Luciana Aparecida Corá
- Alagoas State University of Health Sciences- UNCISAL, Center of Integrative Sciences, Maceio, Alagoas 57010-382, Brazil.
| | - Gustavo Serafim Rodrigues
- São Paulo State University - UNESP, Department of Biophysics and Pharmacology, Institute of Biosciences, Botucatu, São Paulo 18618-689, Brazil.
| | - Andre Gonçalves Prospero
- São Paulo State University - UNESP, Department of Biophysics and Pharmacology, Institute of Biosciences, Botucatu, São Paulo 18618-689, Brazil.
| | - Guilherme Augusto Soares
- São Paulo State University - UNESP, Department of Biophysics and Pharmacology, Institute of Biosciences, Botucatu, São Paulo 18618-689, Brazil.
| | - Uilian de Andreis
- São Paulo State University - UNESP, Department of Biophysics and Pharmacology, Institute of Biosciences, Botucatu, São Paulo 18618-689, Brazil
| | - José Ricardo de Arruda Miranda
- São Paulo State University - UNESP, Department of Biophysics and Pharmacology, Institute of Biosciences, Botucatu, São Paulo 18618-689, Brazil.
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Próspero AG, Soares GA, Moretto GM, Quini CC, Bakuzis AF, de Arruda Miranda JR. Dynamic cerebral perfusion parameters and magnetic nanoparticle accumulation assessed by AC biosusceptometry. BIOMED ENG-BIOMED TE 2020; 65:343-351. [PMID: 31714878 DOI: 10.1515/bmt-2019-0089] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 08/30/2019] [Indexed: 01/25/2023]
Abstract
Cerebral blood flow (CBF) assessment is mainly performed by scintigraphy, computed tomography (CT) and magnetic resonance imaging (MRI). New approaches to assess the CBF through the passage of magnetic nanoparticles (MNPs) to blood-brain barrier (BBB) are convenient to help decrease the use of ionizing radiation and unleash the required MRI schedule in clinics. The development of nanomedicine and new biomedical devices, such as the magnetic particle imaging (MPI), enabled new approaches to study dynamic brain blood flow. In this paper, we employed MNPs and the alternating current biosusceptometry (ACB) to study the brain perfusion. We utilized the mannitol, before the MNPs, injection to modulate the BBB permeability and study its effects on the circulation time of the MNPs in the brain of rats. Also, we characterized a new ACB sensor to increase the systems' applicability to study the MNPs' accumulation, especially in the animals' brain. Our data showed that the injection of mannitol increased the circulation time of MNPs in the brain. Also, the mannitol increased the accumulation of MNPs in the brain. This paper suggests the use of the ACB as a tool to study brain perfusion and accumulation of MNPs in studies of new nano agents focused on the brain diagnostics and treatment.
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Affiliation(s)
- André Gonçalves Próspero
- Department of Physics and Biophysics, UNESP, São Paulo State University, Biosciences Institute of Botucatu, Prof. Antonio Celso Wagner Zanin Street, 18618-689 Botucatu, Brazil
| | - Guilherme Augusto Soares
- Department of Physics and Biophysics, UNESP, São Paulo State University, Biosciences Institute of Botucatu, Botucatu, Brazil
| | - Gustavo Morlin Moretto
- Department of Physics and Biophysics, UNESP, São Paulo State University, Biosciences Institute of Botucatu, Botucatu, Brazil
| | - Caio C Quini
- Department of Physics and Biophysics, UNESP, São Paulo State University, Biosciences Institute of Botucatu, Botucatu, Brazil
| | | | - José Ricardo de Arruda Miranda
- Department of Physics and Biophysics, UNESP, São Paulo State University, Biosciences Institute of Botucatu, Botucatu, Brazil
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Soares GA, Prospero AG, Calabresi MF, Rodrigues DS, Simoes LG, Quini CC, Matos RR, Pinto LA, Sousa-Junior AA, Bakuzis AF, Mancera PA, Miranda JRA. Multichannel AC Biosusceptometry System to Map Biodistribution and Assess the Pharmacokinetic Profile of Magnetic Nanoparticles by Imaging. IEEE Trans Nanobioscience 2019; 18:456-462. [PMID: 30998477 DOI: 10.1109/tnb.2019.2912073] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this paper, the application of a technique to evaluate in vivo biodistribution of magnetic nanoparticles (MNP) is addressed: the Multichannel AC Biosusceptometry System (MC-ACB). It allows real-time assessment of magnetic nanoparticles in both bloodstream clearance and liver accumulation, where a complex network of inter-related cells is responsible for MNP uptake. Based on the acquired MC-ACB images, we propose a mathematical model which helps to understand the distribution and accumulation pharmacokinetics of MNP. The MC-ACB showed a high time resolution to detect and monitor MNP, providing sequential images over the particle biodistribution. Utilizing the MC-ACB instrument, we assessed regions corresponding to the heart and liver, and we determined the MNP transfer rates between the bloodstream and the liver. The pharmacokinetic model resulted in having a strong correlation with the experimental data, suggesting that the MC-ACB is a valuable and accessible imaging device to assess in vivo and real-time pharmacokinetic features of MNP.
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Hauschildt AT, Corá LA, Volpato GT, Sinzato YK, Damasceno DC, Américo MF. Mild diabetes: long-term effects on gastric motility evaluated in rats. Int J Exp Pathol 2018; 99:29-37. [PMID: 29479759 PMCID: PMC5917388 DOI: 10.1111/iep.12262] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 01/04/2018] [Indexed: 12/22/2022] Open
Abstract
Moderate hyperglycaemic levels seem to be related to abnormal gastric motility in diabetes mellitus. However, experimental models designed to evaluate the relationship between motility and diabetes over time are not yet well established. Our objective was to investigate the long-term effects of mild diabetes on gastric motility in rats. Newborn male rats received streptozotocin (mild diabetes groups - MD) or vehicle (control groups - C), and both groups were evaluated after 3 (C3 and MD3) and 6 months (C6 and MD6) postinduction. Mild diabetic animals (MD3 and MD6) showed moderately elevated blood glucose and decreased insulin levels compared with control (C3 and C6). Insulin secretion was enhanced in MD6 compared with MD3, most likely due to partial β-cell regeneration indicated by HOMA-β. In HOMA-IR, it was noticed that MD6 animals had impaired insulin response compared with MD3. Gastric emptying was faster, amplitude of contraction was stronger in MD6 compared with MD3, and in both groups, the differences were significant when compared with control animals. A significant abnormal rhythmic index was calculated for the mild diabetic groups, despite unchanged mean frequency of contraction. In conclusion, despite increased insulin levels over time, constant levels of moderate hyperglycaemia are also related to abnormal gastric motility and impairment of gastric function.
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Affiliation(s)
| | - Luciana A. Corá
- Alagoas State University of Health Sciences – UNCISALMaceió/ALBrazil
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Dall'Agnol DJR, Corá LA, Teixeira MDCB, de Lima MB, Gama LA, Miranda JRDA, Américo MF. Gastrointestinal disorders after immunosuppression: an experimental model to evaluate the influence of monotherapy on motility parameters. Exp Physiol 2017; 102:924-933. [PMID: 28556421 DOI: 10.1113/ep086267] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 05/19/2017] [Indexed: 12/19/2022]
Abstract
NEW FINDINGS What is the central question of this study? The aim was to propose an animal model for investigating the effects of immunosuppressive monotherapy on gastrointestinal motility using a non-invasive biomagnetic technique. What is main finding and its importance? In our experimental study, immunosuppressive drugs currently in use accelerated gastric emptying whilst increasing the frequency and amplitude of gastric contractions after treatment, except for Mycophenolate and azathioprine. Alternating current biosusceptometry is a useful tool to evaluate side-effects of drugs on the gastrointestinal tract, which will help in understanding the symptoms and improving clinical management of patients. The aim was to propose an animal model for investigating the effects of immunosuppressive monotherapy on gastrointestinal motility using a non-invasive biomagnetic technique. Male Wistar rats were randomly distributed into the following treatment groups: ciclosporin, tacrolimus, prednisone, sirolimus, mycophenolate mofetil, everolimus, azathioprine and control. Each animal was treated for 14 days by gavage with dosages ranging from 1 to 20 mg kg-1 day-1 considering the area-to-volume ratio and hepatic metabolism. Gastrointestinal transit and gastric contractility measurements were evaluated by alternating current biosusceptometry before and after treatment. Gastric emptying was faster in animals treated with tacrolimus, prednisone, sirolimus and everolimus compared with control animals (126.7 ± 12.7 min). There was a significant increase in the frequency of contractions after ciclosporin, tacrolimus, azathioprine and sirolimus treatment compared with control animals (4.6 ± 0.3 cycles min-1 ). Increases in the amplitude of contraction were observed after treatment with tacrolimus, sirolimus and everolimus compared with control rats (34.9 ± 6.0 dB). The results showed that our animal model was suitable for demonstrating that most immunosuppressive drugs currently in use impaired at least one gastrointestinal motility parameter. As a non-invasive technique, alternating current biosusceptometry is a potentially useful tool for evaluation of side-effects of drugs in gastrointestinal tract, helping us to understand the symptoms to improve clinical management of patients.
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Affiliation(s)
- Denize Jussara Rupolo Dall'Agnol
- Postgraduate Program in Pharmacology and Biotechnology - São Paulo State University - UNESP, Institute of Biosciences, Botucatu-SP, Brazil
| | | | | | - Maysa Bruno de Lima
- Institute of Biological Sciences and Health - Federal University of Mato Grosso - UFMT, Barra do Garças, Mato Grosso, Brazil
| | - Loyane Almeida Gama
- Postgraduate Program in Pharmacology and Biotechnology - São Paulo State University - UNESP, Institute of Biosciences, Botucatu-SP, Brazil
| | - José Ricardo de Arruda Miranda
- Department of Physics and Biophysics - São Paulo State University - UNESP, Institute of Biosciences - Botucatu/SP, Brazil
| | - Madileine Francely Américo
- Institute of Biological Sciences and Health - Federal University of Mato Grosso - UFMT, Barra do Garças, Mato Grosso, Brazil
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Matos JF, Americo MF, Sinzato YK, Volpato GT, Corá LA, Calabresi MFF, Oliveira RB, Damasceno DC, Miranda JRA. Role of sex hormones in gastrointestinal motility in pregnant and non-pregnant rats. World J Gastroenterol 2016; 22:5761-5768. [PMID: 27433089 PMCID: PMC4932211 DOI: 10.3748/wjg.v22.i25.5761] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/07/2016] [Accepted: 06/02/2016] [Indexed: 02/06/2023] Open
Abstract
AIM: To correlate gastric contractility, gastrointestinal transit, and hormone levels in non-pregnant (estrous cycle) and pregnant rats using noninvasive techniques.
METHODS: Female rats (n = 23) were randomly divided into (1) non-pregnant, (contractility, n = 6; transit, n = 6); and (2) pregnant (contractility, n = 5; transit, n = 6). In each estrous cycle phase or at 0, 7, 14, and 20 d after the confirmation of pregnancy, gastrointestinal transit was recorded by AC biosusceptometry (ACB), and gastric contractility was recorded by ACB and electromyography. After each recording, blood samples were obtained for progesterone and estradiol determination.
RESULTS: In the estrous cycle, despite fluctuations of sex hormone levels, no significant changes in gastrointestinal motility were observed. Days 7 and 14 of pregnancy were characterized by significant changes in the frequency of contractions (3.90 ± 0.42 cpm and 3.60 ± 0.36 cpm vs 4.33 ± 0.25 cpm) and gastric emptying (168 ± 17 min and 165 ± 15 min vs 113 ± 15 min) compared with day 0. On these same days, progesterone levels significantly increased compared with control (54.23 ± 15.14 ng/mL and 129.96 ± 30.52 ng/mL vs 13.25 ± 6.31 ng/mL). On day 14, we observed the highest level of progesterone and the lowest level of estradiol compared with day 0 (44.3 ± 15.18 pg/mL vs 24.96 ± 5.96 pg/mL).
CONCLUSION: Gastrointestinal motility was unaffected by the estrous cycle. In our data, high progesterone and low estradiol levels can be associated with decreased contraction frequency and slow gastric emptying.
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Calabresi MFF, Quini CC, Matos JF, Moretto GM, Americo MF, Graça JRV, Santos AA, Oliveira RB, Pina DR, Miranda JRA. Alternate current biosusceptometry for the assessment of gastric motility after proximal gastrectomy in rats: a feasibility study. Neurogastroenterol Motil 2015; 27:1613-20. [PMID: 26303680 DOI: 10.1111/nmo.12660] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 07/25/2015] [Indexed: 12/12/2022]
Abstract
BACKGROUND This study proposes an experimental model to assess the consequences of gastric surgeries on gastric motility. We investigated the effects of proximal gastrectomy (PG) using a non-invasive technique (alternate current biosusceptometry [ACB]) on gastric contractility (GC), gastric emptying (GE), and orocecal transit (OCT) after the ingestion of liquids and solids in rats. METHODS Twenty-four male rats were subjected to gastric motility assessment before and after the PG procedure. The GE and OCT results are expressed as the mean time of gastric emptying (MGET) and cecum arrival (MCAT). The GC recordings are presented as the frequency and amplitude of contractions. KEY RESULTS Mean time of gastric emptying after solid meals were significantly different (p < 0.001) between control and PG (113 ± 5 to 99 ± 6 min). Mean time of cecum arrival ranged from 265 ± 9 to 223 ± 11 min (p < 0.001) and 164 ± 9 to 136 ± 17 min (p < 0.050) for solid and liquid meals, respectively. The assessment of GC showed that surgery decreased the phasic frequency (4.4 ± 0.4 to 3.0 ± 1.1 cpm, p < 0.050) and increased the amplitude of contractions (3.6 ± 2.7 to 7.2 ± 3.0 V/s, p < 0.050). No significant difference was found in tonic frequency. CONCLUSIONS & INFERENCES The ACB system was able to assess GE, OCT, and GC in gastrectomized rats. Overall, PG accelerated GE and gastrointestinal transit, likely due to the increase in both intragastric pressure and amplitude contraction. Our data presented an efficient model to investigate functional consequences from gastric surgeries that will allow further studies involving different procedures.
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Affiliation(s)
- M F F Calabresi
- Departamento de Física e Biofísica, Instituto de Biociências de Botucatu, UNESP-Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - C C Quini
- Departamento de Física e Biofísica, Instituto de Biociências de Botucatu, UNESP-Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - J F Matos
- Departamento de Física e Biofísica, Instituto de Biociências de Botucatu, UNESP-Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - G M Moretto
- Departamento de Física e Biofísica, Instituto de Biociências de Botucatu, UNESP-Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - M F Americo
- Instituto de Ciências Biológicas e da Saúde, UFMT-Universidade Federal de Mato Grosso, Barra do Garças, Mato Grosso, Brazil
| | - J R V Graça
- Departamento de Fisiologia, Faculdade de Medicina de Sobral, UFC-Universidade Federal do Ceará, Sobral, Ceará, Brazil
| | - A A Santos
- Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, UFC-Universidade Federal do Ceará, Fortaleza, Ceará, Brazil
| | - R B Oliveira
- Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, USP-Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - D R Pina
- Departamento de Doenças Tropicais e Diagnóstico por Imagem, Faculdade de Medicina de Botucatu, UNESP - Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - J R A Miranda
- Departamento de Física e Biofísica, Instituto de Biociências de Botucatu, UNESP-Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
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Teixeira MDCB, Américo MF, Oliveira RB, Miranda JRA, Romeiro FG, Corá LA. Influence of post-transplant immunosuppressive therapy on gastrointestinal transit using biomagnetic method: a pilot study. Dig Dis Sci 2015; 60:174-80. [PMID: 25146844 DOI: 10.1007/s10620-014-3335-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 08/12/2014] [Indexed: 12/28/2022]
Abstract
BACKGROUND Immunosuppressive therapy after kidney transplant is necessary to prevent allograft rejection and it is the cause of several gastrointestinal (GI) disorders that have been scantily studied. OBJECTIVES This study was aimed at investigating the influence of triple immunosuppressive therapy on GI transit in renal transplant patients by employing a biomagnetic technique. METHODS Twenty-one renal transplant patients underwent triple therapy, which included either tacrolimus (TAC) or cyclosporin A (CsA) associated with prednisone and azathioprine. They were all evaluated, and fifteen other healthy individuals formed the control group. After a standardized meal, GI transit of magnetic markers was assessed using Alternating Current Biosusceptometry (ACB). RESULTS Patients taking TAC had significantly accelerated gastric emptying and colonic arrival (p ≤ 0.001) when compared with those taking CsA and those in the control group. However, no differences were observed in small bowel transit among the groups studied. Overall, the inter-subject coefficients of variation for gastrointestinal transit parameters were higher for the TAC group and similar for the CsA and control groups. CONCLUSION This study demonstrated that ACB is a suitable methodology when evaluating the influence of different immunosuppressive therapies on gastrointestinal transit after renal transplantation. Pronounced inter-individual variation was found in patients treated with tacrolimus, thus showing the prokinetic effect of this drug on GI motility. Studies of motility patterns in this population could be useful as complementary information toward determining the mechanisms and the relationship between motility and therapeutic doses.
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Affiliation(s)
- Maria do Carmo B Teixeira
- Centro de Ciências da Saúde, Universidade Estadual de Ciências da Saúde de Alagoas - UNCISAL, Dr Jorge Lima, 113, 57010-382, Maceió, AL, Brazil,
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Marques RG, Americo MF, Spadella CT, Corá LA, Oliveira RB, Miranda JRA. Different patterns between mechanical and electrical activities: an approach to investigate gastric motility in a model of long-term diabetic rats. Physiol Meas 2013; 35:69-81. [PMID: 24345922 DOI: 10.1088/0967-3334/35/1/69] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The relationship between time-courses of mechanical and electrical events in longstanding diabetes was investigated in rats. Magnetic markers and electrodes were surgically implanted in the gastric serosa of male rats. Simultaneous recordings were obtained by AC biosusceptometry, electromyography and electrogastrography one, three and six months after injections of saline (control) or alloxan (diabetic). Frequency and amplitude of contraction, abnormal rhythmic index and half-bandwidth were obtained (ANOVA P < 0.05). Antral hypomotility and gastric motility instability were observed in the signal waveform of diabetic rats at the three time points of study. The mean frequency (4.4 ± 0.4 cpm) was strictly similar, but the mechanical and electrical correlation was lowest for diabetics groups. Decreases in mechanical amplitude were observed for all diabetic groups compared with control; also the ranges of frequency were much wider in diabetes. The half-bandwidth increased since the first month in mechanical recordings and only after the third month in electrical. In diabetic animals, about 40% of gastric activity was abnormal (against 12% in control) and may reach 60% in the sixth month of mechanical recordings. The multi-instrumental approach showed a more substantial deterioration in mechanical activity and created an integrative view of gastric motility for longstanding diabetic model.
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Affiliation(s)
- Rozemeire G Marques
- Faculdade de Medicina de Botucatu, UNESP-Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
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Ferrari PC, Grossklauss DBBDS, Alvarez M, Paixão FC, Andreis U, Crispim AG, Castro ADD, Evangelista RC, Miranda JRDA. A novel automated alternating current biosusceptometry method to characterization of controlled-release magnetic floating tablets of metronidazole. Drug Dev Ind Pharm 2013; 40:1123-31. [DOI: 10.3109/03639045.2013.809537] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Teixeira M, Magalhães I, Galvão P, Souza G, Miranda J, Oliveira R, Corá L. Assessment of Gastrointestinal Motility in Renal Transplant Recipients by Alternate Current Biosusceptometry. Transplant Proc 2012; 44:2384-7. [DOI: 10.1016/j.transproceed.2012.07.048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Paixão FC, Corá LA, Américo MF, de Oliveira RB, Baffa O, Miranda JRA. Development of an AMR-ACB array for gastrointestinal motility studies. IEEE Trans Biomed Eng 2012; 59:2737-43. [PMID: 22996723 DOI: 10.1109/tbme.2012.2208748] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The association between anisotropic magnetoresistive (AMR) sensor and AC biosusceptometry (ACB) to evaluate gastrointestinal motility is presented. The AMR-ACB system was successfully characterized in a bench-top study, and in vivo results were compared with those obtained by means of simultaneous manometry. Both AMR-ACB and manometry techniques presented high temporal cross correlation between the two periodicals signals . The contraction frequencies using AMR-ACB were 73.9 ± 7.6 mHz and using manometry were 73.8 ± 7.9 mHz during the baseline . The amplitude of contraction using AMR-ACB was 396 ± 108 μT·s and using manometry were 540 ± 198 mmHg·s during the baseline. The amplitudes of signals for AMR-ACB and manometric recordings were similarly increased to 86.4% and 89.3% by neostigmine, and also decreased to 27.2% and 21.4% by hyoscine butylbromide in all animals, respectively. The AMR-ACB array is nonexpensive, portable, and has high-spatiotemporal resolution to provide helpful information about gastrointestinal tract.
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Américo MF, Marques RG, Zandoná EA, Andreis U, Stelzer M, Corá LA, Oliveira RB, Miranda JRA. Validation of ACB in vitro and in vivo as a biomagnetic method for measuring stomach contraction. Neurogastroenterol Motil 2010; 22:1340-4, e374. [PMID: 20874731 DOI: 10.1111/j.1365-2982.2010.01582.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND The aim of this study was to validate a biomagnetic method (alternate current biosusceptometry, ACB) for monitoring gastric wall contractions in rats. METHODS In vitro data were obtained to establish the relationship between ACB and the strain-gauge (SG) signal amplitude. In vivo experiments were performed in pentobarbital-anesthetized rats with SG and magnetic markers previously implanted under the gastric serosa or after ingestion of magnetic material. Gastric motility was quantified from the tracing amplitudes and frequency profiles obtained by Fast Fourier Transform. KEY RESULTS The correlation between in vitro signal amplitudes was strong (R = 0.989). The temporal cross-correlation coefficient between the ACB and SG signal amplitude was higher (P < 0.0001) in the postprandial (88.3 ± 9.1 V) than in the fasting state (31.0 ± 16.9 V). Irregular signal profiles, low contraction amplitudes, and smaller signal-to-noise ratios explained the poor correlation between techniques for fasting-state recordings. When a magnetic material was ingested, there was also strong correlation in the frequency and signal amplitude and a small phase-difference between the techniques. The contraction frequencies using ACB were 0.068 ± 0.007 Hz (postprandial) and 0.058 ± 0.007 Hz (fasting) (P < 0.002) and those using SG were 0.066 ± 0.006 Hz (postprandial) and 0.059 ± 0.008 Hz (fasting) (P < 0.005). CONCLUSIONS & INFERENCES In summary, ACB is reliable for monitoring gastric wall contractions using both implanted and ingested magnetic materials, and may serve as an accurate and sensitive technique for gastrointestinal motility studies.
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Affiliation(s)
- M F Américo
- Departamento de Física e Biofísica, Instituto de Biociências, UNESP – Univ Estadual Paulista, Botucatu, São Paulo, Brazil.
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Corá LA, Américo MF, Oliveira RB, Serra CHR, Baffa O, Evangelista RC, Oliveira GF, Miranda JRA. Biomagnetic Methods: Technologies Applied to Pharmaceutical Research. Pharm Res 2010; 28:438-55. [DOI: 10.1007/s11095-010-0285-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Accepted: 09/14/2010] [Indexed: 02/06/2023]
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Varum FJ, Merchant HA, Basit AW. Oral modified-release formulations in motion: The relationship between gastrointestinal transit and drug absorption. Int J Pharm 2010; 395:26-36. [DOI: 10.1016/j.ijpharm.2010.04.046] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 04/30/2010] [Indexed: 10/19/2022]
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