RESUMO
PURPOSE: To describe an experimental surgical model in rats using a dual-plane technique for evaluation of biomaterials in an in-vivo silicone implant coverage. METHODS: This study was developed following the ISO 10993-6 standard. In this study, 40 male Wistar rats weighing between 250 and 350 g were used, distributed into two groups: experimental, biomaterial superimposed on the minimammary prosthesis (MP); and control, MP without implantation of the biomaterial, with eight animals at each biological point: 1, 2, 4, 12, and 26 weeks. Thus, at the end of biological points (1, 2, 4, 12, and 26 weeks; n = 8 animals per week), the tissue specimens achieved were fixed in buffered formalin and stained with hematoxylin-eosin. RESULTS: Macroscopically, throughout the study, no postoperative complications were apparent. In the histological analysis, it was possible to observe the evolution of the inflammatory response, tissue repair, and fibrous capsule during the biological points. CONCLUSIONS: The experimental model described in this study proved to be suitable for evaluating the biomaterial used in the coverage of breast silicone implants.
Assuntos
Materiais Biocompatíveis , Implantes de Mama , Ratos Wistar , Géis de Silicone , Animais , Masculino , Ratos , Teste de Materiais , Modelos Animais , Silicones , Fatores de TempoRESUMO
PURPOSE: To compare the endothelial coverage of different stents in porcine carotid arteries. Research problem: How effective are polyurethane stents (PU) and PU + rapamycin (PU + RAPA) compared to bare-metal stents on endothelial coverage by neointima in pigs after 28 days? METHODS: The methodology had two phases for an interventional, experimental, prospective study, with three Moura pigs, 12 weeks old and weighing between 19 and 22.5 kg. In phase I, eight stents were implanted in carotid arteries; three stents coated with PU, three coated with PU + RAPA, and two without coating. After 28 days, phase II was carried out, consisting of euthanasia, removal of the stents, to evaluate the exposed area of the stent struts, and the percentage of endothelialization through optical microscopy and scanning electron microscopy. RESULTS: The eight stents implanted with ultrasound sizing and post-dilation with a larger diameter balloon were analyzed by Doppler ultrasound, intravascular ultrasound, and angiography after 28 days. CONCLUSIONS: This study showed complete endothelial coverage by the endoluminal neointima of the stent struts, good integration and coverage with the arterial wall, with no exposed struts showing the presence of intimal hyperplasia (whitish tissue).
Assuntos
Stents Farmacológicos , Sirolimo , Animais , Sirolimo/administração & dosagem , Sirolimo/farmacologia , Suínos , Artérias Carótidas/cirurgia , Artérias Carótidas/efeitos dos fármacos , Neointima/patologia , Microscopia Eletrônica de Varredura , Poliuretanos , Estudos Prospectivos , Endotélio Vascular/efeitos dos fármacos , Reprodutibilidade dos Testes , Polímeros , Modelos Animais , Fatores de Tempo , Materiais Revestidos BiocompatíveisAssuntos
Alternativas ao Uso de Animais , Bem-Estar do Animal , Animais , Humanos , Alternativas aos Testes com Animais/ética , Alternativas aos Testes com Animais/tendências , Alternativas ao Uso de Animais/ética , Alternativas ao Uso de Animais/tendências , Bem-Estar do Animal/ética , Bem-Estar do Animal/tendências , Modelos Animais , United States Food and Drug Administration/legislação & jurisprudência , Estados UnidosRESUMO
Ex situ lung perfusion (ESLP) is used for organ reconditioning, repair, and re-evaluation prior to transplantation. Since valid preclinical animal models are required for translationally relevant studies, we developed a 17 mL low-volume ESLP for double- and single-lung application that enables cost-effective optimal compliance "reduction" of the 3R principles of animal research. In single-lung mode, ten Fischer344 and Lewis rat lungs were subjected to ESLP and static cold storage using STEEN or PerfadexPlus. Key perfusion parameters, thermal lung imaging, blood gas analysis (BGA), colloid oncotic pressure (COP), lung weight gain, histological work-up, and cytokine analysis were performed. Significant differences between perfusion solutions but not between the rat strains were detected. Most relevant perfusion parameters confirmed valid ESLP with homogeneous lung perfusion, evidenced by uniform lung surface temperature. BGA showed temperature-dependent metabolic activities with differences depending on perfusion solution composition. COP is not decisive for pulmonary oedema and associated weight gain, but possibly rather observed chemokine profile and dextran sensitivity of rats. Histological examination confirmed intact lung architecture without infarcts or hemorrhages due to optimal organ procurement and single-lung application protocol using our in-house-designed ESLP system.
Assuntos
Pulmão , Perfusão , Ratos Endogâmicos F344 , Ratos Endogâmicos Lew , Animais , Ratos , Perfusão/métodos , Pulmão/fisiologia , Preservação de Órgãos/métodos , Transplante de Pulmão/métodos , Modelos Animais , Masculino , Experimentação AnimalRESUMO
I outline the perspective that searching the contents of memory is a form of mental time travel (MTT) in non-humans that is relatively tractable because it focuses on the contents of memory. I propose that an animal model of MTT requires three elements: (i) the animal remembers multiple events using episodic memory, (ii) the order of events in time is included in the representation, and (iii) the sequence of events can be searched to find a target that occurred at a particular time. I review experiments suggesting that rats represent multiple items in episodic memory (element 1) in order of occurrence (element 2) and engage in memory replay to search representations in episodic memory in sequential order to find information at particular points in the sequence (element 3). The cognitive building blocks needed for MTT may be quite old in the evolutionary timescale.This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.
Assuntos
Memória Episódica , Animais , Ratos , Modelos Animais , CogniçãoRESUMO
PURPOSE: This study aimed to introduce and evaluate two new microvascular anastomosis techniques compared to the conventional method in a rat renal transplant model. METHODS: Using a Fisher-to-Lewis rat kidney transplantation model, the renal artery anastomosis was performed using the interrupted (I) suture technique, Y-shaped continuous (Y) suture technique, and anterior-interrupted and posterior-continuous (I-C) suture technique. The rats were then divided into three groups: I group, Y group, and I-C group. Parameters such as arterial anastomosis time, warm ischemia time, seven-day survival rate of the rats, and vessel histopathology were assessed. RESULTS: The mean arterial anastomosis time, blood leakage scores, and warm ischemia time were significantly reduced in groups Y and I-C compared to group I. Moreover, the seven-day survival rate was significantly higher in the I-C group compared to the other two groups. Arterial histopathology demonstrated vessel wall recovery without damage in all three groups, suggesting the safety of both Y and I-C techniques. CONCLUSIONS: The anterior-interrupted and posterior-continuous suture method is particularly beneficial for small artery reconstruction in organ transplantation.
Assuntos
Anastomose Cirúrgica , Transplante de Rim , Ratos Endogâmicos Lew , Artéria Renal , Técnicas de Sutura , Animais , Transplante de Rim/métodos , Anastomose Cirúrgica/métodos , Masculino , Artéria Renal/cirurgia , Ratos Endogâmicos F344 , Fatores de Tempo , Ratos , Modelos Animais , Isquemia Quente/métodos , Reprodutibilidade dos Testes , Sobrevivência de EnxertoRESUMO
In an interview with Neuron, Cori Bargmann discusses C. elegans as a model organism, the importance of considering the animal's own world (thinking like a worm), choosing a scientific problem, and her experience as head of science at the Chan Zuckerberg Initiative and co-chair of the BRAIN Initiative.
Assuntos
Caenorhabditis elegans , Animais , Neurociências/história , Humanos , Modelos Animais , História do Século XXI , História do Século XXRESUMO
The widely used insecticide chlorpyrifos (CP) is known to inhibit acetylcholinesterase (AChE) activity attributed to result in various neurological disorders and acetylcholine-dependent organ functions including heart, skeletal muscle, lung, gastrointestinal tract, and central nervous systems. Enzyme reactivators, such as oximes, are known to restore AChE activity and mitigate adverse effects. The identification of compounds that reactivate AChE constitute agents with important therapeutic beneficial effects in cases of pesticide poisoning. However, the screening of novel drugs using traditional models may raise ethical concerns. This study aimed to investigate the potential of Drosophila melanogaster as a model organism for screening AChE reactivators, with a focus on organophosphate poisoning. The efficacy of several oximes, including pralidoxime, trimedoxime, obidoxime, methoxime, HI-6, K027, and K048, against CP-induced AChE activity inhibition in D. melanogaster was determined in silico, in vitro, and in vivo experiments. Molecular docking studies indicated a strong interaction between studied oximes and the active-site gorge of AChE. Data showed that selected oximes (100 µM) are effective in the reactivation of AChE inhibited by CP (10 µM) in vitro. Finally, in vivo investigations demonstrated that selected oximes, pralidoxime and K048 (1.5 ppm), reversed the locomotor deficits, inhibition of AChE activity as well as lowered the mortality rates induced by CP (0.75 ppm). Our findings contribute to utilization of D. melanogaster as a robust model for determination of actions of identified new AChE inhibitory agents with more effective therapeutic properties that those currently in use in the clinical practice in treatment of AChE associated disorders.
Assuntos
Acetilcolinesterase , Clorpirifos , Reativadores da Colinesterase , Drosophila melanogaster , Simulação de Acoplamento Molecular , Oximas , Animais , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/enzimologia , Reativadores da Colinesterase/farmacologia , Clorpirifos/toxicidade , Acetilcolinesterase/metabolismo , Oximas/farmacologia , Modelos Animais , Inseticidas/toxicidade , Inibidores da Colinesterase/toxicidadeRESUMO
Third-party punishment (TPP) is an altruistic behavior or sense willing to punish transgressors as a third party not directly involved in the transgression. TPP is observed worldwide, regardless of tradition and culture, and is essential for morality in human society. Moreover, even preverbal infants display TPP-like judgement, suggesting that TPP is evolutionarily conserved and innate. Thus, it is possible that non-human animals display TPP-like behavior, although TPP has been said to be human-specific. We investigated whether or not male mature Wistar rats displayed TPP-like behaviors when they witnessed deadly aggression by an unknown aggressive mouse toward another unknown victim mouse. Normally reared rats did not display TPP-like behaviors, but rats reared with extensive affectionate handling by human caretakers as beloved pets contacted the unknown aggressive mice in a gentle manner leading to reduced aggression toward the unknown victim mice, even when the aggressive mice fought back. Furthermore, the handled rats touched unknown rat pups that were drowning in water and anesthesia-induced comatose rats more frequently than control rats. These findings suggest a possibility that TPP is not in fact human-specific and innate but rather an acquired behavior that flourishes in affectionate circumstances.
Assuntos
Agressão , Comportamento Animal , Punição , Ratos Wistar , Animais , Punição/psicologia , Masculino , Ratos , Agressão/psicologia , Camundongos , Humanos , Modelos Animais , AltruísmoRESUMO
AIMS: In cardiac device implantation, having both surgical skills and ability to manipulate catheter/lead/wire is crucial. Few cardiologists, however, receive formal surgical training prior to implanting. Skills are mostly acquired directly on-the-job and surgical technique varies across institutions; suboptimal approaches may increase complications. We investigated how novel proficiency-based progression (PBP) simulation training impacts the surgical quality of implantations, compared to traditional simulation (SIM) training. METHODS AND RESULTS: In this international prospective study, novice implanters were randomized (blinded) 1:1 to participate in a simulation-based procedure training curriculum, with proficiency demonstration requirements for advancing (PBP approach) or without (SIM). Ultimately, trainees performed the surgical tasks of an implant on a porcine tissue that was video-recorded and then scored by two independent assessors (blinded to group), using previously validated performance metrics. Primary outcomes were the number of procedural Steps Completed, Critical Errors, Errors (non-critical), and All Errors Combined. Thirty novice implanters from 10 countries participated. Baseline experiences were similar between groups. Compared to SIM-trained, the PBP-trained group completed on average 11% more procedural Steps (P < 0.001) and made 61.2% fewer Critical Errors (P < 0.001), 57.1% fewer Errors (P = 0.140), and 60.7% fewer All Errors Combined (P = 0.001); 11/15 (73%) PBP trainees demonstrated the predefined target performance level vs. 3/15 SIM trainees (20%) in the video-recorded performance. CONCLUSION: Proficiency-based progression training produces superior objectively assessed novice operators' surgical performance in device implantation compared with traditional (simulation) training. Systematic PBP incorporation into formal academic surgical skills training is recommended before in vivo device practice. Future studies will quantify PBP training's effect on surgery-related device complications.
Assuntos
Competência Clínica , Treinamento por Simulação , Humanos , Estudos Prospectivos , Feminino , Masculino , Suínos , Currículo , Animais , Análise e Desempenho de Tarefas , Implantação de Prótese/educação , Gravação em Vídeo , Educação de Pós-Graduação em Medicina/métodos , Curva de Aprendizado , Erros Médicos/prevenção & controle , Adulto , Desfibriladores Implantáveis , Cardiologistas/educação , Modelos AnimaisRESUMO
BACKGROUND: Limited treatment options exist for damaged nerves and despite impressive advances in tissue engineering, scientists and clinicians have yet to fully replicate nerve development and recruitment. Innervation is a critical feature for normal organ function. While most organs are innervated prior to birth, a rare example of postnatal nerve recruitment occurs in the natural development of secondary teeth during adolescence. Many animals undergo postnatal shedding of deciduous teeth with development and eruption of secondary teeth, a process requiring recruitment of nerve and vasculature to each tooth pulp for viability. Here, the investigators created a novel model for the study of postnatal innervation by exploiting the natural phenomenon of tooth-driven nerve recruitment. METHODS: The investigators theorized that developing teeth possess a special capacity to induce innervation which could be harnessed in a clinical setting for nerve regeneration, and hyptothesized that a transplant model could be created to capture this phenomenon. In this descriptive study, a rat model of autologous tooth transplantation and de novo nerve recruitment was developed by surgically transferring whole developing molars to the autologous tibia. RESULTS: Downstream histological analysis performed 6 to 14 weeks after surgery demonstrated integration of molar into tibia in 81% of postoperative rats, with progressive pulpal expression of nerve marker ß-tubulin III suggestive of neuronal recruitment. CONCLUSIONS: These findings provide a novel model for the study of organ transplantation and support the theory that developing dental tissues may retain nerve-inductive properties postnatally.
Assuntos
Transplante Autólogo , Animais , Ratos , Polpa Dentária/inervação , Polpa Dentária/citologia , Dente Molar , Modelos Animais , Regeneração Nervosa/fisiologia , Tíbia/cirurgia , Ratos Sprague-DawleyRESUMO
Microtus genus is the herbivorous animal with multiple stomachs, and some of them possess a mating system similar to human and thereby has been expected as a model animal for the large herbivory and human mating system model, respectively. Thus, it is significant to maintain Microtus as an animal genetic resource. We have studied the establishment of assisted reproductive technologies in Alexandromys. montebelli (formerly as Microtus motebelli: A. motebelli), and here, we investigated the effects of hypotaurine treatment to frozen-thawed (FT) spermatozoa and modified timing of nonsurgical artificial insemination (AI) on the number of offspring. As the results, regardless of without or with hypotaurine treatment, when the timing of nonsurgical AI was made closer to the estimated ovulation time (at 7-9 h post coitus), the total number of offspring derived from FT spermatozoa (27 and 28 pups, respectively) increased compared with AI at 4-6 h (five and six pups, respectively) and was equivalent to those of fresh spermatozoa (43 pups) or natural mating (33 pups). These results will lead to further dissemination of nonsurgical AI and could support the "3R principle," which is the standard philosophy of animal experiment because the procedure declines the stress and the recipient can be used repeatedly.
Assuntos
Arvicolinae , Criopreservação , Inseminação Artificial , Preservação do Sêmen , Espermatozoides , Animais , Feminino , Masculino , Arvicolinae/fisiologia , Criopreservação/veterinária , Criopreservação/métodos , Inseminação Artificial/veterinária , Inseminação Artificial/métodos , Modelos Animais , Ovulação , Preservação do Sêmen/veterinária , Preservação do Sêmen/métodos , Espermatozoides/fisiologia , Fatores de TempoRESUMO
Research directly on human embryos has gone through cycles of interest and neglect. The recent revitalization, including the making of 'human developmental biology', depended on fresh supplies of material and demand for medically relevant work. Human studies relied on mice but rejected simple extrapolation from this model mammal. Now, it is time to take stock while scanning the horizon for further change. Will research on human development be facilitated or frustrated? Will comparative approaches bring a greater variety of animal models into the picture? Will human stem-cell-based embryo models secure ever larger roles as exemplars of vertebrate development?
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Biologia do Desenvolvimento , Humanos , Biologia do Desenvolvimento/tendências , Animais , Modelos Animais , Camundongos , Desenvolvimento Embrionário , História do Século XXIAssuntos
Canal Anal , Reto , Animais , Suínos , Reto/cirurgia , Canal Anal/cirurgia , Transplante Autólogo , Modelos AnimaisRESUMO
A transition from nonhuman animal models to engineered microphysiological systems (MPS), such as organoids and organ-on-a-chip technologies, would signal a paradigm shift in biomedical research. Despite MPS' potential to more accurately model human physiology, reduce high failure rates of drugs in clinical trials, and limit unnecessary animal use, widespread adoption is hampered by public opinion and lack of scalability, standardization, and current regulatory uptake. This article suggests how 5 key concepts (awareness, access, education, application, and rewards) could help address these barriers. These concepts are part of a framework that underscores a need to integrate MPS into mainstream biomedical research and to better promote ethical responsibility for the means of biomedical innovation.
Assuntos
Pesquisa Biomédica , Modelos Animais , Pesquisa Biomédica/ética , Humanos , Animais , Organoides , Dispositivos Lab-On-A-Chip , Conscientização , Recompensa , Experimentação Animal/ética , Opinião Pública , Sistemas MicrofisiológicosRESUMO
Although urine bladder transplantation is currently being conducted, the procedure is an incompletely resolved problem in clinical transplantology. A small number of en bloc bladder and kidney transplants from pediatric donors to adult recipients in humans have been reported. A small number of bladder transplants with and without combinations with kidneys have also been performed in experiments on different animal models. Here, we aimed to highlight the experiences of various scientists in bladder transplantation in humans and animals. We also presented our small experience in conducting transplant of 1 kidney, ureters, and a segment of the bladder in an experiment on pigs in 2023 (5 cases), which is a promising direction for further successful development of this technology in humans. In 2024, we plan to conduct another 10 transplants of a single block ofthe kidney and bladderin pigs, results of which will be published after the completion of the experimental work.
Assuntos
Transplante de Rim , Bexiga Urinária , Transplante de Rim/efeitos adversos , Animais , Humanos , Bexiga Urinária/cirurgia , Resultado do Tratamento , Suínos , Adulto , Criança , Doadores de Tecidos/provisão & distribuição , Sobrevivência de Enxerto , Modelos AnimaisRESUMO
The aim of the present study was to evaluate the photothermal effects of a subdermal high-power diode laser at a wavelength (λ) of 1470 nm in the skin of rats. Twenty male Wistar rats were used, divided into 2 groups: placebo laser (PL) and active laser (AL). A high-power diode laser equipment was applied to 5 subdermal vectors on the animal's back region. The results demonstrated that active laser animals showed a better arrangement of collagen fiber bands, an increase in the thickness of the dermis and the number of vessels. Furthermore, animals treated with active laser showed an increased immunoexpression of TGF-ß and VEGF compared to the placebo. The present work demonstrated that the subdermal high-power diode laser increases the vascularization and the expression of factors that enhance skin regeneration and may be promising resource in the esthetic and dermatology clinical treatment of skin rejuvenation.
Assuntos
Lasers Semicondutores , Ratos Wistar , Pele , Animais , Masculino , Ratos , Lasers Semicondutores/uso terapêutico , Pele/efeitos da radiação , Pele/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Rejuvenescimento , Modelos AnimaisRESUMO
BACKGROUND: Junior OB/GYN residents lack opportunities for fundamental surgical skills training of cesarean section, and most OB/GYN residents lack the experience of cervical laceration suturing due to its low incidence. METHODS: A porcine stomach simulation model was designed for obstetrics surgical training. The surface of the stomach simulated the uterus, and the pylorus and cardia simulated the cervical canal. EXPERIENCE: Materials are available from the nearby market. The total cost of the model isï¿¥41. This model can be used in the training in uterus incision and repair of cesarean section and training in cervical laceration suturing. CONCLUSION: The porcine stomach simulation model is pragmatic and realistic. They can be applied in the OB/GYN skill courses to introduce the fundamental obstetrics process to medical students and residents.
Assuntos
Cesárea , Lacerações , Treinamento por Simulação , Estômago , Técnicas de Sutura , Animais , Suínos , Cesárea/educação , Técnicas de Sutura/educação , Feminino , Lacerações/cirurgia , Estômago/cirurgia , Estômago/lesões , Humanos , Gravidez , Obstetrícia/educação , Colo do Útero/cirurgia , Colo do Útero/lesões , Modelos Animais , Competência Clínica , Modelos AnatômicosRESUMO
AIM: Aging and age-related diseases are an ever-increasing social and public health problem. Allostatic load (AL) shows great potential as an interdisciplinary tool for assessing the aging of human beings but as yet lacks investigation in animal models which is our study focus at. METHODS: Here a continuous study of AL was conducted on naturally aging rats. Blood samples were collected from the rats at ages of 5, 8, 14, 18, and 21 months. Dozens of blood biochemical indicators, including serum corticosterone, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, C-reactive protein, interleukin-6, 25-hydroxyvitamin D, free fatty acid, CD3+ T cell count, CD4+/CD3+ T cell ratio, CD8+/CD3+ T cell ratio, and CD3/4/8+ T cell apoptosis, were determined. RESULTS: AL was scored from those indicators, and we found that AL score gradually increased with age. CONCLUSIONS: AL can reliably reveal the cumulative and systemic changes in aging. Geriatr Gerontol Int 2024; 24: 1077-1084.
Assuntos
Envelhecimento , Alostase , Animais , Ratos , Alostase/fisiologia , Envelhecimento/fisiologia , Masculino , Proteína C-Reativa/metabolismo , Proteína C-Reativa/análise , Corticosterona/sangue , Interleucina-6/sangue , Triglicerídeos/sangue , Vitamina D/sangue , Vitamina D/análogos & derivados , Modelos Animais de Doenças , Colesterol/sangue , Modelos AnimaisRESUMO
Current research using animal models to investigate retinal cell biology and model retinal degenerative diseases largely utilize small mammals that are nocturnal and lack the ability to restore lost vision. In contrast, the Mongolian gerbil (Meriones) is a diurnal rodent with good photopic vision, and the spiny mouse (Acomys) is a small desert-dwelling rodent with remarkable regenerative capabilities. The goal of this study was to identify antibodies that detect retinal cell classes in Meriones and Acomys, and to describe the retinal anatomy of these two species in comparison to outbred laboratory mice (Mus musculus). Immunohistochemistry was performed on retinal sections with antibodies for various retinal cell types. Sections were imaged by light, fluorescence, and confocal microscopy. Cell density, morphology, and placement were compared between species qualitatively and quantitatively. Our analyses revealed a classic assembly of retinal cells in Meriones and Acomys, with a few deviations compared to Mus. Meriones displayed the highest density of cones and Acomys the lowest. A higher density of bipolar cell bodies in the proximal portion of the inner nuclear layer was observed in both Acomys and Meriones compared to Mus, and both species exhibited an increase in amacrine cell density compared to Mus. Our results provide a foundation for future research into the visual system adaptations of these interesting species.