Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
Nano Lett ; 24(9): 2894-2903, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38407042

RESUMO

Harnessing the potential of tumor-associated macrophages (TAMs) to engulf tumor cells offers promising avenues for cancer therapy. Targeting phagocytosis checkpoints, particularly the CD47-signal regulatory protein α (SIRPα) axis, is crucial for modulating TAM activity. However, single checkpoint inhibition has shown a limited efficacy. In this study, we demonstrate that ferrimagnetic vortex-domain iron oxide (FVIO) nanoring-mediated magnetic hyperthermia effectively suppresses the expression of CD47 protein on Hepa1-6 tumor cells and SIRPα receptor on macrophages, which disrupts CD47-SIRPα interaction. FVIO-mediated magnetic hyperthermia also induces immunogenic cell death and polarizes TAMs toward M1 phenotype. These changes collectively bolster the phagocytic ability of macrophages to eliminate tumor cells. Furthermore, FVIO-mediated magnetic hyperthermia concurrently escalates cytotoxic T lymphocyte levels and diminishes regulatory T cell levels. Our findings reveal that magnetic hyperthermia offers a novel approach for dual down-regulation of CD47 and SIRPα, reshaping the tumor microenvironment to stimulate immune responses, culminating in significant antitumor activity.


Assuntos
Hipertermia Induzida , Neoplasias , Humanos , Antígeno CD47 , Regulação para Baixo , Imunoterapia , Fagocitose , Fenômenos Magnéticos , Neoplasias/patologia , Microambiente Tumoral
2.
J Hepatol ; 80(6): 928-940, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38336346

RESUMO

BACKGROUND & AIMS: Men are more prone to develop and die from liver fibrosis than women. In this study, we aim to investigate how sex-determining region Y gene (SRY) in hepatocytes promotes liver fibrosis. METHODS: Hepatocyte-specific Sry knock-in (KI), Sry knockout (KO), and Sry KI with platelet-derived growth factor receptor α (Pdgfrα) KO mice were generated. Liver fibrosis was induced in mice by bile duct ligation for 2 weeks or carbon tetrachloride treatment for 6 weeks. In addition, primary hepatocytes, hepatic stellate cells (HSCs), and immortalized cell lines were used for in vitro studies and mechanistic investigation. RESULTS: Compared to females, the severity of toxin- or cholestasis-induced liver fibrosis is similarly increased in castrated and uncastrated male mice. Among all Y chromosome-encoded genes, SRY was the most significantly upregulated and consistently increased gene in fibrotic/cirrhotic livers in male patients and in mouse models. Sry KI mice developed exacerbated liver fibrosis, whereas Sry KO mice had alleviated liver fibrosis, compared to age- and sex-matched control mice after bile duct ligation or administration of carbon tetrachloride. Mechanistically, both our in vivo and in vitro studies illustrated that SRY in hepatocytes can transcriptionally regulate Pdgfrα expression, and promote HMGB1 (high mobility group box 1) release and subsequent HSC activation. Pdgfrα KO or treatment with the SRY inhibitor DAX1 in Sry KI mice abolished SRY-induced HMGB1 secretion and liver fibrosis. CONCLUSIONS: SRY is a strong pro-fibrotic factor and accounts for the sex disparity observed in liver fibrosis, suggesting its critical role as a potentially sex-specific therapeutic target for prevention and treatment of the disease. IMPACT AND IMPLICATION: We identified that a male-specific gene, sex-determining region Y gene (SRY), is a strong pro-fibrotic gene that accounts for the sex disparity observed in liver fibrosis. As such, SRY might be an appropriate target for surveillance and treatment of liver fibrosis in a sex-specific manner. Additionally, SRY might be a key player in the sexual dimorphism observed in hepatic pathophysiology more generally.


Assuntos
Células Estreladas do Fígado , Hepatócitos , Cirrose Hepática , Camundongos Knockout , Proteína da Região Y Determinante do Sexo , Animais , Masculino , Feminino , Camundongos , Cirrose Hepática/genética , Cirrose Hepática/metabolismo , Cirrose Hepática/fisiopatologia , Humanos , Hepatócitos/metabolismo , Proteína da Região Y Determinante do Sexo/genética , Proteína da Região Y Determinante do Sexo/metabolismo , Células Estreladas do Fígado/metabolismo , Caracteres Sexuais , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Tetracloreto de Carbono/toxicidade , Tetracloreto de Carbono/efeitos adversos , Colestase/genética , Colestase/metabolismo , Colestase/fisiopatologia , Modelos Animais de Doenças
3.
J Surg Oncol ; 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38894619

RESUMO

OBJECTIVES: The objective of the current study was to characterize prognostic factors related to long-term recurrence-free survival after curative-intent resection of intrahepatic cholangiocarcinoma (ICC). METHODS: Data on patients who underwent curative-intent resection for ICC between 2000 and 2020 were collected from an international multi-institutional database. Prognostic factors were investigated among patients who recurred within 5 years versus long-term survivors who survived more than 5 years with no recurrence. RESULTS: Among 635 patients who underwent curative-intent resection for ICC, 104 (16.4%) patients were long-term survivors with no recurrence beyond 5 years after surgery. Patients who survived for more than 5 years with no recurrence were more likely to have less aggressive tumor features, as well as have undergone an R0 resection versus patients who recurred within 5 years after resection. On multivariable analysis, tumor size (>5 cm) (HR: 1.535, 95% CI: 1.254-1.879), satellite lesions (HR: 1.253, 95% CI: 1.003-1.564), and lymph node metastasis (HR: 1.733, 95% CI: 1.349-2.227) were independently associated with recurrence within 5 years. Patients who recurred beyond 5 years (n = 23), 2-5 years (n = 60), and within 2 years (n = 471) had an incrementally worse post-recurrence survival (PRS, 28.0 vs. 20.0 vs. 12.0 months, p = 0.032). Among patients with N0 status, tumor size (>5 cm) (HR: 1.612, 95% CI: 1.087-2.390) and perineural invasion (PNI) (HR: 1.562,95% CI: 1.081-2.255) were risk factors associated with recurrence. Among patients with N1 disease, only a minority (5/128, 3.9%) of patients survived with no recurrence to 5 years. CONCLUSION: Roughly 1 in 6 patients survived for more than 5 years with no recurrence following curative-intent resection of ICC. Among N0 patients, tumor recurrence was associated with tumor size and PNI. Only a small subset of N1 patients experienced long-term survival.

4.
BMC Gastroenterol ; 24(1): 20, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38182996

RESUMO

BACKGROUND: To investigate the feasibility of a deformable self-assembled magnetic anastomosis ring (DSAMAR), designed and developed by us, for endoscopic gastrointestinal bypass anastomosis. METHODS: Ten experimental pigs were used as model animals. The DSAMAR comprises 10 trapezoidal magnetic units, arranged in a straight line under the constraint of a guide wire. When the desired anastomosis site is reached under the guidance of an endoscope, the catheter pushes the magnetic unit along the guide wire. The linear DSAMAR can be assembled into a circular DSAMAR. Two DSAMARs were inserted, one at the end of the duodenum and the other into the stomach successively. They attracted each other and compressed the wall of the stomach and duodenum to establish gastrointestinal bypass anastomosis. The experimental pigs were euthanized 4 weeks after the operation, and the gastrointestinal bypass anastomosis specimens were obtained. The anastomosis formation was evaluated by the naked eye and histology. RESULTS: Gastrointestinal bypass anastomosis with DSAMARs was successfully performed. The average operation time under an endoscope was 70.30 ± 19.05 min (range: 43-95 min). The DSAMARs were discharged through the anus 10-17 days after surgery. There were no complications such as gastrointestinal bleeding, perforation, anastomotic fistula, and gastrointestinal obstruction during and after the operation. Gastroscopy and gross specimen of the anastomosis showed a well-formed magnetic anastomosis. Histological observation showed good continuity of the serous membrane and the mucosa of magnetic anastomosis. CONCLUSION: The DSAMAR is a safe and feasible device for fashioning gastrointestinal bypass anastomosis in this animal model.


Assuntos
Gastroscopia , Estômago , Suínos , Animais , Anastomose Cirúrgica , Estômago/cirurgia , Duodeno , Fenômenos Magnéticos
5.
BMC Med Imaging ; 24(1): 112, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38755567

RESUMO

Accurate preoperative differentiation of the chronic rhinosinusitis (CRS) endotype between eosinophilic CRS (eCRS) and non-eosinophilic CRS (non-eCRS) is an important topic in predicting postoperative outcomes and administering personalized treatment. To this end, we have constructed a sinus CT dataset, which comprises CT scan data and pathological biopsy results from 192 patients of chronic rhinosinusitis with nasal polyps (CRSwNP), treated at the Second Affiliated Hospital of Shantou University Medical College between 2020 and 2022. To differentiate CRSwNP endotype on preoperative CT and improve efficiency at the same time, we developed a multi-view fusion model that contains a mini-architecture with each network of 10 layers by modifying the deep residual neural network. The proposed model is trained on a training set and evaluated on a test set. The multi-view deep learning fusion model achieved the area under the receiver-operating characteristics curve (AUC) of 0.991, accuracy of 0.965 and F1-Score of 0.970 in test set. We compared the performance of the mini-architecture with other lightweight networks on the same Sinus CT dataset. The experimental results demonstrate that the developed ResMini architecture contribute to competitive CRSwNP endotype identification modeling in terms of accuracy and parameter number.


Assuntos
Aprendizado Profundo , Pólipos Nasais , Rinite , Sinusite , Tomografia Computadorizada por Raios X , Humanos , Tomografia Computadorizada por Raios X/métodos , Sinusite/diagnóstico por imagem , Rinite/diagnóstico por imagem , Pólipos Nasais/diagnóstico por imagem , Pólipos Nasais/cirurgia , Pólipos Nasais/patologia , Doença Crônica , Redes Neurais de Computação , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Curva ROC
6.
J Environ Sci (China) ; 145: 117-127, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38844312

RESUMO

Atmospheric particulate matter (PM) exacerbates the risk factor for Alzheimer's and Parkinson's diseases (PD) by promoting the alpha-synuclein (α-syn) pathology in the brain. However, the molecular mechanisms of astrocytes involvement in α-syn pathology underlying the process remain unclear. This study investigated PM with particle size <200 nm (PM0.2) exposure-induced α-syn pathology in ICR mice and primary astrocytes, then assessed the effects of mammalian target of rapamycin inhibitor (PP242) in vitro studies. We observed the α-syn pathology in the brains of exposed mice. Meanwhile, PM0.2-exposed mice also exhibited the activation of glial cell and the inhibition of autophagy. In vitro study, PM0.2 (3, 10 and 30 µg/mL) induced inflammatory response and the disorders of α-syn degradation in primary astrocytes, and lysosomal-associated membrane protein 2 (LAMP2)-mediated autophagy underlies α-syn pathology. The abnormal function of autophagy-lysosome was specifically manifested as the expression of microtubule-associated protein light chain 3 (LC3II), cathepsin B (CTSB) and lysosomal abundance increased first and then decreased, which might both be a compensatory mechanism to toxic α-syn accumulation induced by PM0.2. Moreover, with the transcription factor EB (TFEB) subcellular localization and the increase in LC3II, LAMP2, CTSB, and cathepsin D proteins were identified, leading to the restoration of the degradation of α-syn after the intervention of PP242. Our results identified that PM0.2 exposure could promote the α-syn pathological dysregulation in astrocytes, providing mechanistic insights into how PM0.2 increases the risk of developing PD and highlighting TFEB/LAMP2 as a promising therapeutic target for antagonizing PM0.2 toxicity.


Assuntos
Astrócitos , Autofagia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Proteína 2 de Membrana Associada ao Lisossomo , Lisossomos , Camundongos Endogâmicos ICR , Material Particulado , alfa-Sinucleína , Animais , Astrócitos/efeitos dos fármacos , alfa-Sinucleína/metabolismo , Autofagia/efeitos dos fármacos , Camundongos , Lisossomos/metabolismo , Lisossomos/efeitos dos fármacos , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Proteína 2 de Membrana Associada ao Lisossomo/metabolismo , Material Particulado/toxicidade , Poluentes Atmosféricos/toxicidade
7.
Rev Cardiovasc Med ; 24(10): 294, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39077580

RESUMO

Background: The risk of sudden cardiac death (SCD) after coronary revascularization in patients with left ventricular (LV) systolic dysfunction has not been characterized completely. This study aims to evaluate the incidence and time course of SCD after revascularization in such patients. The determinants of SCD within 3 months after revascularization were also assessed. Methods: A cohort study of patients with reduced ejection fraction (EF ≤ 40%), who underwent revascularization was performed. The incidence of SCD was estimated to account for the competing risk of deaths due to other causes. Results: 2317 patients were enrolled. With a median follow-up of 3.5 years, 162 (32.1%) of the 504 deaths were due to SCD. The risk of SCD was highest in the first 3 months after revascularization, with an incidence rate of 0.37%/month. The event rate decreased to 0.12%/month, 0.08%/month, 0.09%/month, 0.14%/month, and 0.19%/month at 3-6 months, 6-12 months, 1-3 years, 3-5 years, and 5-10 years, respectively. A history of ventricular tachycardia/ventricular fibrillation (hazard ratio [HR], 5.55; 95% confidence interval [CI], 1.33-23.19; p = 0.019) and triple vessel disease (HR, 3.90; 95% CI, 1.38-11.05; p = 0.010) were associated with the risk of SCD within 3 months. However, preoperative EF (in 5% increments) was not predictive (HR per 5% increase, 0.98; 95% CI, 0.62-1.55; p = 0.935). Conclusions: For patients with LV dysfunction, the risk of SCD was the highest during the first 3 months after revascularization. Further risk classification and treatment strategy are warranted. Clinical Trial Registration: The name of the registry: Coronary Revascularization in Patients with Ischemic Heart Failure and Prevention of Sudden Cardiac Death. Registration number: ChiCTR2100044378.

8.
World J Gastrointest Surg ; 16(3): 860-870, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38577092

RESUMO

BACKGROUND: Despite much work having been conducted on magnetic compression anastomosis (MCA) in the digestive tract, there are no reports on the influence of magnetic force on the anastomosis. AIM: To investigate the effect of different magnetic force magnets on the MCA of the digestive tract. METHODS: Two groups of magnets of the same sizes but different magnetic forces were designed and produced. A total of 24 Sprague-Dawley rats were randomly assigned into two groups (powerful magnet group and common magnet group), with 12 rats in each group. Two types of magnets were used to complete the colonic side-to-side anastomosis of the rats. The operation time and magnet discharge time were recorded. The anastomotic specimens were obtained 4 wk after the operation and then the burst pressure and diameter of the anastomosis were measured, and the anastomosis was observed via the naked eye and subjected to histological examination. RESULTS: The magnetic forces of the powerful and common magnet groups at zero distance were 8.26 N and 4.10 N, respectively. The colonic side-to-side anastomosis was completed in all 24 rats, and the operation success rate and postoperative survival rate were 100%. No significant difference was noted in the operation time between the two groups. The magnet discharge time of the powerful magnet group was slightly longer than that of the common magnet group, but the difference was not statistically significant (P = 0.513). Furthermore, there was no statistical difference in the burst pressure (P = 0.266) or diameter of magnetic anastomosis (P = 0.095) between the two groups. The gross specimens of the two groups showed good anastomotic healing, and histological observation indicated good mucosal continuity without differences on healing. CONCLUSION: In the rat colonic side-to-side MCA model, both the powerful magnet with 8.26 N and the common magnet with 4.10 N showed no significant impact on the anastomosis establishment process or its effect.

9.
Sci Rep ; 14(1): 1865, 2024 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-38253773

RESUMO

Magnetic compression anastomosis has been reported to have remarkable clinical outcomes. Here, we tested the applicability of a Y-Z deformable magnetic ring (DMR) for non-surgical manipulation of rectal stenosis (RS) in a beagle dog model under a transanal single-access condition. RS was modeled in 8 beagle dogs using partial ligation with silk thread. Under X-ray guidance, the Y-Z DMR was positioned at the proximal and distal ends of the RS, and the magnetic ring was bent into an "O" shape, such that the two rings were magnetically attracted. Operation time, complications during or after operation, and discharge time of the magnetic rings were recorded. The anastomosis bursting pressure was measured two weeks after removing the rings, and its formation was assessed through gross and histological examination. Partial ligation with a silk thread successfully established the canine RS model. After Y-Z DMR installation, the magnetic ring was successfully reconfigured from an "S" to an "O" shape. Strong attraction existed between the rings. The operation time was 9-15 min (average: 11.75 ± 1.98 min). No rectal bleeding or perforation occurred during or after operation. The ring was naturally expelled 7-10 days after surgery. A pressure of > 300 mmHg was recorded at the point of anastomosis rupture. The rectal anastomosis appeared to have healed properly on the surface, which was confirmed histologically, signifying the success of this procedure. A Y-Z DMR facilitated the successful recanalization of transanal single-channel RS without needing surgery in an animal model.


Assuntos
Fenômenos Magnéticos , Seda , Animais , Cães , Constrição Patológica/cirurgia , Fenômenos Físicos , Anastomose Cirúrgica
10.
World J Gastroenterol ; 30(6): 599-606, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38463020

RESUMO

BACKGROUND: Treatment of postoperative anastomotic stenosis for colorectal cancer is often challenging, especially for patients who do not respond well to endoscopy. In cases where patients have undergone an enterostomy, the stenosis can be easily resolved through magnetic compression. However, common magnetic compression techniques cannot be performed on those without enterostomy. We designed a novel Y-Z deformable magnetic ring (Y-Z DMR) and successfully applied it to a patient with a stenosis rectal anastomosis and without enterostomy after rectal cancer surgery. CASE SUMMARY: We here report the case of a 57-year-old woman who had undergone a laparoscopic radical rectum resection (Dixon) for rectal cancer. However, she started facing difficulty in defecation 6 months after surgery. Her colonoscopy indicated stenosis of the rectal anastomosis. Endoscopic balloon dilation was performed six times on her. However, the stenosis still showed a trend of gradual aggravation. Because the patient did not undergo an enterostomy, the conventional endoscopic magnetic compression technique could not be performed. Hence, we implemented a Y-Z DMR implemented through the anus under single channel. The magnetic ring fell off nine days after the operation and the rectal stenosis was relieved. The patient was followed up for six months and reported good defecation. CONCLUSION: The Y-Z DMR deformable magnetic ring is an excellent treatment strategy for patients with rectal stenosis and without enterostomy.


Assuntos
Laparoscopia , Neoplasias Retais , Humanos , Feminino , Pessoa de Meia-Idade , Constrição Patológica/cirurgia , Constrição Patológica/etiologia , Neoplasias Retais/complicações , Neoplasias Retais/cirurgia , Reto/diagnóstico por imagem , Reto/cirurgia , Laparoscopia/efeitos adversos , Anastomose Cirúrgica/efeitos adversos , Complicações Pós-Operatórias/etiologia , Fenômenos Magnéticos , Estudos Retrospectivos
11.
Sci Rep ; 14(1): 7907, 2024 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575669

RESUMO

Vesicovaginal fistula lacks a standard, established animal model, making surgical innovations for this condition challenging. Herein, we aimed to non-surgically establish vesicovaginal fistula using the magnetic compression technique, and the feasibility of this method was explored using eight female Beagle dogs as model animals. In these dogs, cylindrical daughter and parent magnets were implanted into the bladder and vagina, respectively, after anesthesia, and the positions of these magnets were adjusted under X-ray supervision to make them attract each other, thus forming the structure of daughter magnet-bladder wall-vaginal wall-parent magnet. Operation time and collateral damage were recorded. The experimental animals were euthanized 2 weeks postoperatively, and the vesicovaginal fistula gross specimens were obtained. The size of the fistula was measured. Vesicovaginal fistula was observed by naked eye and under a light microscope. Magnet placement was successful in all dogs, and remained in the established position for the reminder of the experiment. The average operation time was 14.38 min ± 1.66 min (range, 12-17 min). The dogs were generally in good condition postoperatively and were voiding normally, with no complications like bleeding and urine retention. The magnets were removed from the vagina after euthanasia. The vesicovaginal fistula was successfully established according to gross observation, and the fistula diameters were 4.50-6.24 mm. Histological observation revealed that the bladder mucosa and vaginal mucosa were in close contact on the internal surface of the fistula. Taken together, magnetic compression technique is a simple and feasible method to establish an animal model of vesicovaginal fistula using Beagle dogs. This model can help clinicians study new surgical techniques and practice innovative approaches for treating vesicovaginal fistula.


Assuntos
Fístula Vesicovaginal , Humanos , Cães , Animais , Feminino , Fístula Vesicovaginal/cirurgia , Fístula Vesicovaginal/etiologia , Bexiga Urinária/cirurgia , Vagina/cirurgia , Magnetismo , Fenômenos Magnéticos
12.
Sci Rep ; 14(1): 10602, 2024 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719935

RESUMO

Although the application of magnetic compression anastomosis is becoming increasingly widespread, the magnets used in earlier studies were mostly in the shape of a whole ring. Hence, a deformable self-assembled magnetic anastomosis ring (DSAMAR) was designed in this study for gastrointestinal anastomosis. Furthermore, its feasibility was studied using a beagle model. The designed DSAMAR comprised 10 trapezoidal magnetic units. Twelve beagles were used as animal models, and DSAMARs were inserted into the stomach and colon through the mouth and anus, respectively, via endoscopy to achieve gastrocolic magnamosis. Surgical time, number of failed deformations, survival rate of the animals, and the time of magnet discharge were documented. A month later, specimens of the anastomosis were obtained and observed with the naked eye as well as microscopically. In the gastrocolic anastomosis of the 12 beagles, the procedure took 65-120 min. Although a deformation failure occurred during the operation in one of the beagles, it was successful after repositioning. The anastomosis was formed after the magnet fell off 12-18 days after the operation. Naked eye and microscopic observations revealed that the anastomotic specimens obtained 1 month later were well-formed, smooth, and flat. DSAMAR is thus feasible for gastrointestinal anastomosis under full endoscopy via the natural orifice.


Assuntos
Anastomose Cirúrgica , Estudos de Viabilidade , Animais , Cães , Anastomose Cirúrgica/métodos , Estômago/cirurgia , Imãs , Magnetismo , Cirurgia Endoscópica por Orifício Natural/métodos , Cirurgia Endoscópica por Orifício Natural/instrumentação , Colo/cirurgia , Masculino
13.
Heliyon ; 10(15): e35646, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39170310

RESUMO

Introduction: Traditional/ritual/medical circumcision can be associated with considerable intraoperative blood loss and a prolonged postoperative healing course. This study investigated the feasibility of the magnetic compression technique (MCT) for circumcision in beagle dogs. Methods: A set of magnetic rings including a daughter magnetic ring (DMR) and a parent magnetic ring (PMR) were designed for circumcision. In eight beagle dogs as the animal model, the DMR was placed between the penis and the foreskin through the glans, and then the PMR was placed outside the penis. The DMR and PMR automatically attracted together to compress the foreskin. The necrosis of the prepuce of the anterior penis was observed daily. The operation time and time to magnetic ring shedding were recorded. Healing of the foreskin stump was visually observed. Results: The magnetic rings were successfully installed in all eight dogs, and the operation process was without complication. The average operation time was 3.13 ± 0.92 min (range, 2-4.5 min). Postoperative X-rays showed good attraction of the magnetic rings. Daily post-operative observation showed progressive ischemic necrosis of the anterior foreskin and mild edema of the proximal foreskin. The dogs were generally in good condition and urinated freely. The magnetic rings fell off spontaneously 8-12 days after the operation, and the stump of the foreskin healed well. Conclusion: The MCT may be a new approach for circumcision in a canine model, which suggests its potential for use in humans.

14.
Sci Rep ; 14(1): 12462, 2024 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-38816430

RESUMO

Various surgical methods have so far been developed for treating rectovaginal fistula (RVF), each with its own advantages and disadvantages. The lack of standardized animal models of RVF is a major reason for the failure to establish a unified and effective surgical method for the treatment of RVF. This study aimed to explore the feasibility of an RVF animal model by magnetic compression and compare it with the traditional modeling method. Thirty-two female Japanese white rabbits were randomly divided into four groups: A, B, C, and D, based on how the rectovaginal septum was treated. The operation time, intraoperative blood loss, and model success rate of each group were determined. The experimental animals were euthanized 2 weeks after the operation. Their rectovaginal septum specimens were obtained. RVF was observed by the naked eye. The fistula size was measured. Histological changes of fistula were observed by hematoxylin and eosin and Masson staining. All rabbits completed the RVF model and survived 2 weeks after the operation. Groups A and B had no bleeding, while groups C and D had < 0.5 mL of bleeding. The magnet detached in 4-6 days in group A, while it remained in place for 2 weeks after surgery in group B. Only one group D rabbit had a plastic hose for 2 weeks after surgery. The RVFs of groups A and C healed by themselves. In group B, the fistula was well formed. In group D, fistula healing was observed in three animals and the diameter of the fistulas was only 2.82-4.64 mm in the other four animals. Groups B and D had a scar on the inner surface of fistulas. Our study shows that the magnetic compression technique based on the T-shaped magnet is a highly useful method to establishing a continuous and stable RVF model in rabbits.


Assuntos
Modelos Animais de Doenças , Fístula Retovaginal , Animais , Coelhos , Feminino , Fístula Retovaginal/cirurgia , Fístula Retovaginal/patologia
15.
World J Gastroenterol ; 30(16): 2272-2280, 2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38690021

RESUMO

BACKGROUND: The magnetic compression technique has been used to establish an animal model of tracheoesophageal fistula (TEF), but the commonly shaped magnets present limitations of poor homogeneity of TEF and poor model control. We designed a T-shaped magnet system to overcome these problems and verified its effectiveness via animal experiments. AIM: To investigate the effectiveness of a T-shaped magnet system for establishing a TEF model in beagle dogs. METHODS: Twelve beagles were randomly assigned to groups in which magnets of the T-shaped scheme (study group, n = 6) or normal magnets (control group, n = 6) were implanted into the trachea and esophagus separately under gastroscopy. Operation time, operation success rate, and accidental injury were recorded. After operation, the presence and timing of cough and the time of magnet shedding were observed. Dogs in the control group were euthanized after X-ray and gastroscopy to confirm establishment of TEFs after coughing, and gross specimens of TEFs were obtained. Dogs in the study group were euthanized after X-ray and gastroscopy 2 wk after surgery, and gross specimens were obtained. Fistula size was measured in all animals, and then harvested fistula specimens were examined by hematoxylin and eosin (HE) and Masson trichrome staining. RESULTS: The operation success rate was 100% for both groups. Operation time did not differ between the study group (5.25 min ± 1.29 min) and the control group (4.75 min ± 1.70 min; P = 0.331). No bleeding, perforation, or unplanned magnet attraction occurred in any animal during the operation. In the early postoperative period, all dogs ate freely and were generally in good condition. Dogs in the control group had severe cough after drinking water at 6-9 d after surgery. X-ray indicated that the magnets had entered the stomach, and gastroscopy showed TEF formation. Gross specimens of TEFs from the control group showed the formation of fistulas with a diameter of 4.94 mm ± 1.29 mm (range, 3.52-6.56 mm). HE and Masson trichrome staining showed scar tissue formation and hierarchical structural disorder at the fistulas. Dogs in the study group did not exhibit obvious coughing after surgery. X-ray examination 2 wk after surgery indicated fixed magnet positioning, and gastroscopy showed no change in magnet positioning. The magnets were removed using a snare under endoscopy, and TEF was observed. Gross specimens showed well-formed fistulas with a diameter of 6.11 mm ± 0.16 mm (range, 5.92-6.36 mm), which exceeded that in the control group (P < 0.001). Scar formation was observed on the internal surface of fistulas by HE and Masson trichrome staining, and the structure was more regular than that in the control group. CONCLUSION: Use of the modified T-shaped magnet scheme is safe and feasible for establishing TEF and can achieve a more stable and uniform fistula size compared with ordinary magnets. Most importantly, this model offers better controllability, which improves the flexibility of follow-up studies.


Assuntos
Modelos Animais de Doenças , Imãs , Traqueia , Fístula Traqueoesofágica , Animais , Cães , Fístula Traqueoesofágica/cirurgia , Fístula Traqueoesofágica/patologia , Fístula Traqueoesofágica/etiologia , Traqueia/cirurgia , Traqueia/patologia , Esôfago/cirurgia , Esôfago/patologia , Esôfago/diagnóstico por imagem , Gastroscopia/instrumentação , Gastroscopia/métodos , Duração da Cirurgia , Masculino , Magnetismo/instrumentação , Desenho de Equipamento , Humanos
16.
Sci Rep ; 14(1): 14265, 2024 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-38902360

RESUMO

With the increasing application of magnetic compression anastomosis (MCA) in gastrointestinal anastomosis, we identified an interesting phenomenon that an anastomosis is more prone to stenosis after endoscopic gastrointestinal MCA. We hypothesized that the increase in tissue tension during endoscopic procedures is the cause of anastomotic stenosis. In this study, we investigated the effect of tissue tension on gastroduodenal bypass MCA in Sprague-Dawley (SD) rats. Twenty SD rats were divided into the study group (high-tension group, n = 10) and control group (no tension group, n = 10), wherein the rats underwent complete gastroduodenal bypass magnetic anastomosis under high tension and no tension of the digestive tract, respectively. Anastomotic specimens were obtained 4 weeks after the operation, and anastomotic diameters of the two groups were observed and measured. The histological difference was observed by hematoxylin & eosin and Masson staining. The operation was successfully completed in all rats, and all survived until 4 weeks postoperatively. Anastomotic measurements revealed that the anastomosis diameter was significantly smaller in the study group than in the control group, and there were three cases of severe anastomotic stenosis. Histological observation showed that the amount of collagen fibers in the anastomosis was greater in the study group than in the control group. The results suggest that the high-tension state of the digestive tract is an important factor leading to anastomotic stenosis, and thus, we put forward the Yan-Zhang's Tissue Tension Theory of MCA to explain this phenomenon.


Assuntos
Anastomose Cirúrgica , Ratos Sprague-Dawley , Animais , Anastomose Cirúrgica/métodos , Ratos , Masculino , Trato Gastrointestinal/cirurgia , Constrição Patológica/cirurgia , Magnetismo
17.
Bioelectrochemistry ; 158: 108726, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38733722

RESUMO

Mucus hypersecretion resulting from excessive proliferation and metaplasia of goblet cells in the airways is the pathological foundation for Chronic obstructive pulmonary disease (COPD). Clinical trials have confirmed the clinical efficacy of pulsed electric field ablation (PFA) for COPD, but its underlying mechanisms is poorly understood. Cellular and animal models of COPD (rich in goblet cells) were established in this study to detect goblet cells' sensitivity to PFA. Schwan's equation was adopted to calculate the cells' transmembrane potential and the electroporation areas in the cell membrane. We found that goblet cells are more sensitive to low-intensity PFA (250 V/cm-500 V/cm) than BEAS-2B cells. It is attributed to the larger size of goblet cells, which allows a stronger transmembrane potential formation under the same electric field strength. Additionally, the transmembrane potential of larger-sized cells can reach the cell membrane electroporation threshold in more areas. Trypan blue staining confirmed that the cells underwent IRE rate was higher in goblet cells than in BEAS-2B cells. Animal experiments also confirmed that the airway epithelium of COPD is more sensitive to PFA. We conclude that lower-intensity PFA can selectively kill goblet cells in the COPD airway epithelium, ultimately achieving the therapeutic effect of treating COPD.


Assuntos
Eletroporação , Células Caliciformes , Doença Pulmonar Obstrutiva Crônica , Células Caliciformes/patologia , Doença Pulmonar Obstrutiva Crônica/patologia , Doença Pulmonar Obstrutiva Crônica/metabolismo , Doença Pulmonar Obstrutiva Crônica/terapia , Animais , Humanos , Eletroporação/métodos , Linhagem Celular , Potenciais da Membrana , Masculino , Técnicas de Ablação/métodos , Eletricidade , Camundongos
18.
World J Gastrointest Surg ; 16(5): 1443-1448, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38817285

RESUMO

BACKGROUND: The treatment of postoperative anastomotic stenosis (AS) after resection of colorectal cancer is challenging. Endoscopic balloon dilation is used to treat stenosis in such cases, but some patients do not show improvement even after multiple balloon dilations. Magnetic compression technique (MCT) has been used for gastrointestinal anastomosis, but its use for the treatment of postoperative AS after colorectal cancer surgery has rarely been reported. CASE SUMMARY: We report a 72-year-old man who underwent radical resection of colorectal cancer and ileostomy one year ago. An ileostomy closure was prepared six months ago, but colonoscopy revealed a narrowing of the rectal anastomosis. Endoscopic balloon dilation was performed three times, but colonoscopy showed no significant improvement in stenosis. The AS was successfully treated using MCT. CONCLUSION: MCT is a minimally invasive method that can be used for the treatment of postoperative AS after colorectal cancer surgery.

19.
Biomaterials ; 309: 122599, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38703409

RESUMO

Development of bioadhesives that can be facilely delivered by endoscope and exhibit instant and robust adhesion with gastric tissues to promote gastric ulcer healing remains challenging. In this study, an advanced bioadhesive is prepared through free radical polymerization of ionized N-acryloyl phenylalanine (iAPA) and N-[tris (hydroxymethyl) methyl] acrylamide (THMA). The precursory polymer solution exhibits low viscosity with the capability for endoscope delivery, and the hydrophilic-hydrophobic transition of iAPA upon exposure to gastric acid can trigger gelation through phenyl groups assisted multiple hydrogen bonds formation and repel water molecules on tissue surface to establish favorable environment for interfacial interactions between THMA and functional groups on tissues. The in-situ formed hydrogel features excellent stability in acid environment (14 days) and exhibits firm wet adhesion to gastric tissue (33.4 kPa), which can efficiently protect the wound from the stimulation of gastric acid and pepsin. In vivo studies reveal that the bioadhesive can accelerate the healing of ulcers by inhibiting inflammation and promoting capillary formation in the acetic acid-induced gastric ulcer model in rats. Our work may provide an effective solution for the treatment of gastric ulcers clinically.


Assuntos
Úlcera Gástrica , Cicatrização , Animais , Úlcera Gástrica/tratamento farmacológico , Úlcera Gástrica/induzido quimicamente , Cicatrização/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Ratos , Ratos Sprague-Dawley , Masculino , Hidrogéis/química , Adesivos Teciduais/química , Adesivos Teciduais/farmacologia , Fenilalanina/química
20.
iScience ; 27(6): 110029, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38883844

RESUMO

Sorafenib, a first-line drug for advanced hepatocellular carcinoma (HCC), unfortunately encounters resistance in most patients, leading to disease progression. Traditional approaches to counteract this resistance, particularly those targeting the RAF-MEK-ERK pathway, often face clinical feasibility limitations. Magnetic hyperthermia (MH), unlike conventional thermal therapies, emerges as a promising alternative. It uniquely combines magnetothermal effects with an increase in reactive oxygen species (ROS). This study found the potential of intracellular MH enhanced the efficacy of sorafenib, increased cellular sensitivity to sorafenib, and reversed sorafenib resistance by inhibiting the RAF-MEK-ERK pathway in an ROS-dependent manner in a sorafenib-resistant HCC cell. Further, in a sorafenib-resistant HCC mouse model, MH significantly sensitized tumors to sorafenib therapy, resulting in inhibited tumor growth and improved survival rates. This presents a promising strategy to overcome sorafenib resistance in HCC, potentially enhancing therapeutic outcomes for patients with this challenging condition.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA