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Prospero AG, Pinto LA, Matos RVR, Soares GA, Oliveira RB, Mascarenhas S, Miranda JRDA. New device for active gastric mechanical stimulation. Neurogastroenterol Motil 2021; 33:e14169. [PMID: 33969918 DOI: 10.1111/nmo.14169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Revised: 04/16/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND Gastroparesis is a chronic stomach disorder and effective treatment is the aim of different strategies. Alternative therapies consist of an electrical stimulation of the stomach to evoke a response in the gastric activity. We present the development and in vivo application of an electromagnet system to induce a mechanical stimulus in the stomach aiming for gastric contractile responses. METHODS The electromagnet system consisted of an implantable magnet and an external drive coil. We implanted the magnet at the greater curvature of the gastric body in rats. We applied an alternating current to the drive coils, inducing mechanical stimulation of the gastric wall. We measured the gastric contraction activity and gastric electrical activity in response to the stimulus using AC biosusceptometry and electrogastrography. Moreover, we used the phenol red to evaluate the stimulus effects on gastrointestinal transit. KEY RESULTS The stimulus increased the spectral intensity and signal-to-noise ratio significantly of gastric contraction activity and gastric electrical activity. Furthermore, we found a lower phenol red retention in the stomach in rats without stimulus. No significant differences were found in frequency and root mean square amplitude. CONCLUSIONS & INFERENCES We developed a new simple electromagnet system that evoked a contraction and gastric electrical response using a mechanical stimulus and decreased gastric emptying time. The system is an accessible tool and may contribute to gastroparesis studies in animals.
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Affiliation(s)
- Andre Gonçalves Prospero
- Departamento de Biofísica e Farmacologia, Laboratório de Biomagnetismo, UNESP/São Paulo State University, Botucatu, Brazil
| | - Leonardo Antonio Pinto
- Departamento de Biofísica e Farmacologia, Laboratório de Biomagnetismo, UNESP/São Paulo State University, Botucatu, Brazil
| | - Ronaldo Vitor Reis Matos
- Departamento de Biofísica e Farmacologia, Laboratório de Biomagnetismo, UNESP/São Paulo State University, Botucatu, Brazil
| | - Guilherme Augusto Soares
- Departamento de Biofísica e Farmacologia, Laboratório de Biomagnetismo, UNESP/São Paulo State University, Botucatu, Brazil
| | - Ricardo Brandt Oliveira
- Faculdade de Medicina de Ribeirão Preto, USP/University of São Paulo, Ribeirão Preto, Brazil
| | | | - José Ricardo de Arruda Miranda
- Departamento de Biofísica e Farmacologia, Laboratório de Biomagnetismo, UNESP/São Paulo State University, Botucatu, Brazil
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2D Quantitative Imaging of Magnetic Nanoparticles by an AC Biosusceptometry Based Scanning Approach and Inverse Problem. SENSORS 2021; 21:s21217063. [PMID: 34770373 PMCID: PMC8587841 DOI: 10.3390/s21217063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 01/08/2023]
Abstract
The use of magnetic nanoparticles (MNPs) in biomedical applications requires the quantitative knowledge of their quantitative distribution within the body. AC Biosusceptometry (ACB) is a biomagnetic technique recently employed to detect MNPs in vivo by measuring the MNPs response when exposed to an alternate magnetic field. The ACB technique presents some interesting characteristics: non-invasiveness, low operational cost, high portability, and no need for magnetic shielding. ACB conventional methods until now provided only qualitative information about the MNPs’ mapping in small animals. We present a theoretical model and experimentally demonstrate the feasibility of ACB reconstructing 2D quantitative images of MNPs’ distributions. We employed an ACB single-channel scanning approach, measuring at 361 sensor positions, to reconstruct MNPs’ spatial distributions. For this, we established a discrete forward problem and solved the ACB system’s inverse problem. Thus, we were able to determine the positions and quantities of MNPs in a field of view of 5×5×1 cm3 with good precision and accuracy. The results show the ACB system’s capabilities to reconstruct the quantitative spatial distribution of MNPs with a spatial resolution better than 1 cm, and a sensitivity of 1.17 mg of MNPs fixed in gypsum. These results show the system’s potential for biomedical application of MNPs in several studies, for example, electrochemical-functionalized MNPs for cancer cell targeting, quantitative sensing, and possibly in vivo imaging.
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Prospero AG, Buranello LP, Fernandes CA, Dos Santos LD, Soares G, C Rossini B, Zufelato N, Bakuzis AF, de Mattos Fontes MR, de Arruda Miranda JR. Corona protein impacts on alternating current biosusceptometry signal and circulation times of differently coated MnFe 2O 4 nanoparticles. Nanomedicine (Lond) 2021; 16:2189-2206. [PMID: 34533056 DOI: 10.2217/nnm-2021-0195] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Background: We evaluated the impacts of corona protein (CP) formation on the alternating current biosusceptometry (ACB) signal intensity and in vivo circulation times of three differently coated magnetic nanoparticles (MNP): bare, citrate-coated and bovine serum albumin-coated MNPs. Methods: We employed the ACB system, gel electrophoresis and mass spectrometry analysis. Results: Higher CP formation led to a greater reduction in the in vitro ACB signal intensity and circulation time. We found fewer proteins forming the CP for the bovine serum albumin-coated MNPs, which presented the highest circulation time in vivo among the MNPs studied. Conclusion: These data showed better biocompatibility, stability and magnetic signal uniformity in biological media for bovine serum albumin-coated MNPs than for citrate-coated MNPs and bare MNPs.
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Affiliation(s)
- Andre Gonçalves Prospero
- Department of Biophysics and Pharmacology, São Paulo State University, Botucatu, São Paulo, 18618-689, Brazil
| | - Lais Pereira Buranello
- Department of Biophysics and Pharmacology, São Paulo State University, Botucatu, São Paulo, 18618-689, Brazil
| | - Carlos Ah Fernandes
- Department of Biophysics and Pharmacology, São Paulo State University, Botucatu, São Paulo, 18618-689, Brazil.,Museum National d'Histoire Naturelle, Institut de Minéralogie, Physique des Matériaux et Cosmochimie, IMPMC, Sorbonne Université, UMR 7590, CNRS, Paris, France
| | - Lucilene Delazari Dos Santos
- Graduate Program in Tropical Diseases, Botucatu Medical School (FMB), São Paulo State University (UNESP), Botucatu, São Paulo, 18618-687, Brazil.,Biotechnology Institute, São Paulo State University, Botucatu, São Paulo, 18607-440, Brazil
| | - Guilherme Soares
- Department of Biophysics and Pharmacology, São Paulo State University, Botucatu, São Paulo, 18618-689, Brazil
| | - Bruno C Rossini
- Biotechnology Institute, São Paulo State University, Botucatu, São Paulo, 18607-440, Brazil
| | - Nícholas Zufelato
- Institute of Physics and CNanoMed, Federal University of Goiás, Goiânia, 74690-900, Brazil
| | | | - Marcos R de Mattos Fontes
- Department of Biophysics and Pharmacology, São Paulo State University, Botucatu, São Paulo, 18618-689, Brazil
| | - José R de Arruda Miranda
- Department of Biophysics and Pharmacology, São Paulo State University, Botucatu, São Paulo, 18618-689, Brazil
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Pinto L, Soares G, Próspero A, Stoppa E, Biasotti G, Paixão F, Santos A, Oliveira R, Miranda J. An easy and low-cost biomagnetic methodology to study regional gastrointestinal transit in rats. ACTA ACUST UNITED AC 2021; 66:405-412. [PMID: 33544465 DOI: 10.1515/bmt-2020-0202] [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: 08/03/2020] [Accepted: 01/19/2021] [Indexed: 12/12/2022]
Abstract
The identification of gastrointestinal (GI) motility disorders requires the evaluation of regional GI transit, and the development of alternative methodologies in animals has a significant impact on translational approaches. Therefore, the purpose of this study was to validate an easy and low-cost methodology (alternate current biosusceptometry - ACB) for the assessment of regional GI transit in rats through images. Rats were fed a test meal containing magnetic tracer and phenol red, and GI segments (stomach, proximal, medial and distal small intestine, and cecum) were collected to assess tracer's retention at distinct times after ingestion (0, 60, 120, 240, and 360 min). Images were obtained by scanning the segments, and phenol red concentration was determined by the sample's absorbance. The temporal retention profile, geometric center, gastric emptying, and cecum arrival were evaluated. The correlation coefficient between methods was 0.802, and the temporal retention of each segment was successfully assessed. GI parameters yielded comparable results between methods, and ACB images presented advantages as the possibility to visualize intrasegmental tracer distribution and the automated scan of the segments. The imaging approach provided a reliable assessment of several parameters simultaneously and may serve as an accurate and sensitive approach for regional GI research in rats.
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Affiliation(s)
- Leonardo Pinto
- Department of Biophysics and Pharmacology, São Paulo State University, Biosciences Institute of Botucatu, Botucatu, Brazil
| | - Guilherme Soares
- Department of Biophysics and Pharmacology, São Paulo State University, Biosciences Institute of Botucatu, Botucatu, Brazil
| | - André Próspero
- Department of Biophysics and Pharmacology, São Paulo State University, Biosciences Institute of Botucatu, Botucatu, Brazil
| | - Erick Stoppa
- Department of Biophysics and Pharmacology, São Paulo State University, Biosciences Institute of Botucatu, Botucatu, Brazil
| | - Gabriel Biasotti
- Department of Biophysics and Pharmacology, São Paulo State University, Biosciences Institute of Botucatu, Botucatu, Brazil
| | - Fabiano Paixão
- Science and Technology Institute, Federal University of São Paulo, São José dos Campos, Brazil
| | - Armênio Santos
- Department of Physiology and Pharmacology, Federal University of Ceará, Fortaleza, Brazil
| | - Ricardo Oliveira
- Ribeirão Preto Medical School, São Paulo University, Ribeirão Preto, Brazil
| | - José Miranda
- Department of Biophysics and Pharmacology, São Paulo State University, Biosciences Institute of Botucatu, Botucatu, 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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Prospero AG, Fidelis-de-Oliveira P, Soares GA, Miranda MF, Pinto LA, Dos Santos DC, Silva VDS, Zufelato N, Bakuzis AF, Miranda JR. AC biosusceptometry and magnetic nanoparticles to assess doxorubicin-induced kidney injury in rats. Nanomedicine (Lond) 2020; 15:511-525. [PMID: 32077357 DOI: 10.2217/nnm-2019-0300] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Aim: This paper aims to investigate a doxorubicin (DOX) chronic kidney disease rat model using magnetic nanoparticles (MNPs) associated with the alternate current biosusceptometry (ACB) to analyze its different perfusion profiles in both healthy and DOX-injured kidneys. Materials & methods: We used the ACB to detect the MNP kidney perfusion in vivo. Furthermore, we performed biochemical and histological analyses, which sustained results obtained from the ACB system. We also studied the MNP biodistribution. Results: We found that DOX kidney injury alters the MNPs' kidney perfusion. These changes became more intense as the disease progressed. Moreover, DOX has an important effect on MNP biodistribution as the disease evolved. Conclusion: This study provides new applications of MNPs in nephrology, instrumentation, pharmacology, physiology and nanomedicine.
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Affiliation(s)
- Andre G Prospero
- Departamento de Física e Biofísica, IBB, Universidade Estadual Paulista, Botucatu, São Paulo, 18618-689, Brazil
| | | | - Guilherme A Soares
- Departamento de Física e Biofísica, IBB, Universidade Estadual Paulista, Botucatu, São Paulo, 18618-689, Brazil
| | - Milena F Miranda
- Departamento de Física e Biofísica, IBB, Universidade Estadual Paulista, Botucatu, São Paulo, 18618-689, Brazil
| | - Leonardo A Pinto
- Departamento de Física e Biofísica, IBB, Universidade Estadual Paulista, Botucatu, São Paulo, 18618-689, Brazil
| | - Daniela C Dos Santos
- Departamento de Patologia, Universidade Estadual Paulista, Botucatu, São Paulo, 18618-687, Brazil
| | - Vanessa Dos S Silva
- Departamento de Clínica Médica, Universidade Estadual Paulista, Botucatu, São Paulo, 18618-687, Brazil
| | - Nicholas Zufelato
- Instituto de Física, Universidade Federal de Goiás, Alameda Palmeiras St, Goiânia, 74690-900, Brazil
| | - Andris F Bakuzis
- Instituto de Física, Universidade Federal de Goiás, Alameda Palmeiras St, Goiânia, 74690-900, Brazil
| | - José Ra Miranda
- Departamento de Física e Biofísica, IBB, Universidade Estadual Paulista, Botucatu, São Paulo, 18618-689, Brazil
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7
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Nunes ADC, Gomes-Silva LA, Zufelato N, Prospero AG, Quini CC, Matos RVR, Miranda JRA, Bakuzis AF, Castro CH. Albumin Coating Prevents Cardiac Effect of the Magnetic Nanoparticles. IEEE Trans Nanobioscience 2019; 18:640-650. [PMID: 31398127 DOI: 10.1109/tnb.2019.2931962] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have showed that surface layer can determine cardiac effects of the magnetic nanoparticles (MNPs). Considering the high binding capacity of albumin and low side-effects, the aim of this study was to evaluate the influence of albumin coating on the cardiovascular effects of two manganese ferrite-based MNPs: citrate-coated and bare MNPs. Isolated rat hearts were perfused with citrate-coated magnetic nanoparticles (CiMNPs), citrate albumin-coated magnetic nanoparticles (CiAlbMNPs), bare magnetic nanoparticles (BaMNPs), and albumin-coated magnetic nanoparticles (AlbMNPs). CiMNPs induce a transient decrease in the left ventricular end-systolic pressure, +dP/dt and -dP/dt. These effects were not worsened by albumin coating. BaMNPs significantly increased the left ventricular end-diastolic pressure and perfusion pressure and decreased the +dP/dt and -dP/dt. These effects were completely absent in hearts perfused with AlbMNPs. None of the MNPs changed heart rate or arterial blood pressure in conscious rats. Magnetic signals in isolated hearts perfused with BaMNPs were significantly higher than AlbMNPs perfused hearts. However, the magnetic signal in heart tissue was similar when the MNPs were infused in conscious rats. These data indicate that albumin-coated can reduce cardiovascular effects of MNPs. These findings suggest a protective effect of albumin surface in MNPs, favoring its future therapeutic applications.
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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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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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Martins ML, Calabresi MF, Quini C, Matos JF, Miranda JR, Saeki MJ, Bordallo HN. Enhancing the versatility of alternate current biosusceptometry (ACB) through the synthesis of a dextrose-modified tracer and a magnetic muco-adhesive cellulose gel. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2015; 48:80-5. [DOI: 10.1016/j.msec.2014.11.059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 11/22/2014] [Indexed: 02/06/2023]
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Bruno AC, Pavan TZ, Baffa O, Carneiro AAO. A hybrid transducer to magnetically and ultrasonically evaluate magnetic fluids. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2013; 60:2004-2012. [PMID: 24658731 DOI: 10.1109/tuffc.2013.2785] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Ultrasound, magnetic fields, and optical techniques have been explored for clinical diagnosis and therapy. However, these techniques have limitations. In this study, we constructed and characterized a transducer to magnetically and ultrasonically investigate samples labeled with magnetic particles. The transducer is a hybrid system consisting of an ac biosusceptometer (ACB) and an ultrasonic transducer. The basic operation principle consisted of measuring the magnetization and microvibrations of ferromagnetic particles (37 and 70 μm) mixed in yogurt and excited by an external alternating magnetic field generated by the ACB's excitation coils. The vibration of the ferromagnetic particles was measured in phantoms using a Doppler ultrasonic transducer; we verified the sensitivity to detecting the vibrations at low concentrations of ferromagnetic material (~1%). The responses of the susceptometer and Doppler ultrasound linearly depended on the voltage level applied to the magnetizing coils at low ferromagnetic particle concentrations (⩽ 5%). We also conducted a repeatability test on the prototype, which indicated a deviation of 0.94% and 0.25% in the Doppler and susceptometric measurements, respectively. We can conclude that the hybrid transducer technique has potential clinical applications.
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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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13
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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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Quini CC, Américo MF, Corá LA, Calabresi MF, Alvarez M, Oliveira RB, Miranda JRA. Employment of a noninvasive magnetic method for evaluation of gastrointestinal transit in rats. J Biol Eng 2012; 6:6. [PMID: 22587220 PMCID: PMC3412735 DOI: 10.1186/1754-1611-6-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 05/15/2012] [Indexed: 02/08/2023] Open
Abstract
AC Biosusceptometry (ACB) was previously employed towards recording gastrointestinal motility. Our data show a reliable and successful evaluation of gastrointestinal transit of liquid and solid meals in rats, considering the methods scarcity and number of experiments needed to endorsement of drugs and medicinal plants. ACB permits real time and simultaneous experiments using the same animal, preserving the physiological conditions employing both meals with simplicity and accuracy.
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Affiliation(s)
- Caio C Quini
- Instituto de Biociências de Botucatu, IBB - Universidade Estadual Paulista - UNESP, Distrito de Rubião Jr s/n, Botucatu, São Paulo, CEP: 18600-000, Brazil.
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Agostinho M, Américo MF, Marques RG, Zandoná EA, Stelzer M, Corá LA, Andreis U, Oliveira RB, Miranda JRA. AC Biosusceptometry as a method for measuring gastric contraction. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2011; 2010:5740-3. [PMID: 21097331 DOI: 10.1109/iembs.2010.5627855] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The aim of this study was to validate the alternate current biosusceptometry (ACB) for monitoring gastric contractions in rats. In vitro data were obtained to establish the relationship between ACB and the strain-gauge (SG) signal amplitude. In vivo experiments were performed on rats with magnetic markers and SGs previously implanted under the gastric serosa. The effects of the prandial state in gastric motility profiles were obtained. The correlation between in vitro signal amplitudes was strong (R = 0.989). The temporal cross-correlation between the ACB and SG signal amplitude was higher in the postprandial than in the fasting state. Irregular signal profiles, low contraction amplitudes, and smaller signal-to-noise ratios explained the poor correlation for fasting-state recordings. The contraction frequencies using ACB were 0.068 ± 0.007 Hz (postprandial) and 0.058 ± 0.007 Hz (fasting) and those using SG were 0.066 ± 0.006 Hz (postprandial) and 0.059 ± 0.008 Hz (fasting) (P < 0.003). When a magnetic tracer was ingested, there was a strong correlation and a small phase-difference between techniques. We conclude that ACB provides an accurate and sensitive technique for studies of GI motility in the rat.
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Américo MF, Ietsugu MV, Romeiro FG, Corá LA, Oliveira RB, Miranda JRA. Effects of meal size and proximal-distal segmentation on gastric activity. World J Gastroenterol 2010; 16:5861-8. [PMID: 21155008 PMCID: PMC3001978 DOI: 10.3748/wjg.v16.i46.5861] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To evaluate the effects of meal size and three segmentations on intragastric distribution of the meal and gastric motility, by scintigraphy.
METHODS: Twelve healthy volunteers were randomly assessed, twice, by scintigraphy. The test meal consisted of 60 or 180 mL of yogurt labeled with 64 MBq 99mTc-tin colloid. Anterior and posterior dynamic frames were simultaneously acquired for 18 min and all data were analyzed in MatLab. Three proximal-distal segmentations using regions of interest were adopted for both meals.
RESULTS: Intragastric distribution of the meal between the proximal and distal compartments was strongly influenced by the way in which the stomach was divided, showing greater proximal retention after the 180 mL. An important finding was that both dominant frequencies (1 and 3 cpm) were simultaneously recorded in the proximal and distal stomach; however, the power ratio of those dominant frequencies varied in agreement with the segmentation adopted and was independent of the meal size.
CONCLUSION: It was possible to simultaneously evaluate the static intragastric distribution and phasic contractility from the same recording using our scintigraphic approach.
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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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Miranda JRA, Corá LA, Américo MF, Romeiro FG. AC biosusceptometry technique to evaluate the gastrointestinal transit of pellets under influence of prandial state. J Pharm Sci 2010; 99:317-24. [PMID: 19431208 DOI: 10.1002/jps.21794] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Multiparticulate dosage forms have been proposed when distal regions of gastrointestinal tract are desirable as target of drugs. It is known that physiological parameters might interfere with the processes related to the drug delivery and absorption and therefore, it is essential to evaluate the behavior of such delivery systems in vivo. The aim of this study was to propose the AC Biosusceptometry technique as a noninvasive and radiation free device to evaluate the gastrointestinal transit of a magnetic multiparticulate dosage form in healthy volunteers under fasting and fed conditions. Magnetic pellets were prepared by the powder layering method of ferrite on nonpareils sugar beads and coated by using Eudragit. Our data showed that the AC Biosusceptometry technique was able to monitoring the gastrointestinal transit of pellets presenting similar profiles as demonstrated by standard techniques. Food intake has markedly influenced the gastric emptying as well as the colon arrival and the small intestine transit of magnetic pellets.
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Affiliation(s)
- José Ricardo A Miranda
- Department of Physics and Biophysics, Biosciences Institute, IBB, Sao Paulo State University, UNESP, PO Box 510, 18618-000 Botucatu, Sao Paulo, Brazil
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Américo MF, Oliveira RB, Corá LA, Marques RG, Romeiro FG, Andreis U, Miranda JRA. The ACB technique: a biomagentic tool for monitoring gastrointestinal contraction directly from smooth muscle in dogs. Physiol Meas 2009; 31:159-69. [DOI: 10.1088/0967-3334/31/2/003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Pharmaceutical applications of AC biosusceptometry. Eur J Pharm Biopharm 2009; 74:67-77. [PMID: 19482083 DOI: 10.1016/j.ejpb.2009.05.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 05/19/2009] [Accepted: 05/22/2009] [Indexed: 12/28/2022]
Abstract
AC Biosusceptometry offers an alternative to investigate noninvasively and without ionizing radiation the behavior of solid dosage forms in vitro and in the human gastrointestinal tract. This versatility allowed applying this technique in a wide field ranging from characterization of the disintegration process to elucidation of how the physiological parameters can interfere with pharmaceutical processes. It is increasingly important to understand how oral solid dosage forms behave in the human gastrointestinal tract. Once labelled, magnetic dosage forms provide an excellent opportunity to investigate complexes' interactions between dosage form and gastrointestinal physiology. In this paper, basic principles of this biomagnetic instrumentation and of the quantification based on magnetic images are reviewed. Also will be presented are some of the most recent applications of AC Biosusceptometry in the pharmaceutical research including oesophageal transit, gastric emptying and transit time of multiparticulate dosage forms, hydrophilic matrices and disintegration of tablets.
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Américo MF, Miranda JRA, Corá LA, Romeiro FG. Electrical and mechanical effects of hyoscine butylbromide on the human stomach: a non-invasive approach. Physiol Meas 2009; 30:363-70. [PMID: 19282558 DOI: 10.1088/0967-3334/30/4/002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Due to the importance of motility in a number of gastrointestinal disorders, efforts have been made to evaluate both gastric motility counterparts: electrical activity and mechanical activity. The present work aimed to propose a new approach, associating AC biosusceptometry (ACB) and electrogastrography (EGG), to noninvasively monitoring mechanical and electrical gastric activity, respectively. Fourteen volunteers ingested a test meal and their gastric activity was evaluated by EGG and ACB at a baseline and after 20 mg of i.v. hyoscine butylbromide. ACB and EGG showed a similar signal pattern and high temporal correlation. Hyoscine butylbromide decreased the mechanical motility index (MI) by 50.9%, while for electrical MI the reduction was 36.5%. Delayed times to onset (mean+/-SD: 50+/-15 versus 40+/-20 s; P<0.01) and the inhibitory effect (16+/-4 versus 14+/-5 min; P<0.01) were calculated for ACB and EGG, respectively. ACB and EGG emerged due to their interesting nature, noninvasiveness and low cost to evaluate gastric motility. Our approach associating ACB and EGG allowed monitoring and quantification of the effects of an anticholinergic drug in gastric electrical activity and contractile activity in humans.
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Affiliation(s)
- Madileine F Américo
- Departamento de Física e Biofísica, Instituto de Biociências, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil
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Andreis U, Américo MF, Corá LA, Oliveira RB, Baffa O, Miranda JRA. Gastric motility evaluated by electrogastrography and alternating current biosusceptometry in dogs. Physiol Meas 2008; 29:1023-31. [PMID: 18698113 DOI: 10.1088/0967-3334/29/9/002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Association techniques could be the answer for evaluating electromechanical coupling and gastric emptying under basal conditions and after administration of drugs. Electrogastrography (EGG) and alternating current biosusceptometry (ACB) emerged due to their interesting nature, noninvasiveness and low cost. The aims were to examine in dogs the effect of erythromycin on gastric emptying by ACB and electrical and motor responses to erythromycin and propranolol by ACB and EGG respectively. Twelve beagle dogs ingested a solid test meal on separate days. Under anesthesia, gastric motility was evaluated by EGG and ACB after erythromycin and propranolol administration. Without anesthesia, gastric emptying was assessed under basal conditions and after erythromycin by ACB. ACB and EGG showed a strong temporal correlation. Erythromycin and propranolol presented the same profile with different power ratios; the amplitude increased whereas frequency decreased. Also, erythromycin administration hastened gastric emptying while reducing the orocaecal transit time. There is a demand for reliable, easy-to-perform and comfortable techniques to record gastric emptying and gastric activity in medicine and veterinary practice. In summary, the association of ACB with EGG accompanied by an appropriate animal model is promising for evaluating effects of drugs in gastric myoelectrical and contractile activity.
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Affiliation(s)
- Uilian Andreis
- Departamento de Física e Biofísica, IBB, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil
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