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1.
Proc Natl Acad Sci U S A ; 120(36): e2221704120, 2023 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-37639604

RESUMEN

While deep learning has enabled significant advances in many areas of science, its black-box nature hinders architecture design for future artificial intelligence applications and interpretation for high-stakes decision-makings. We addressed this issue by studying the fundamental question of how deep neural networks process data in the intermediate layers. Our finding is a simple and quantitative law that governs how deep neural networks separate data according to class membership throughout all layers for classification. This law shows that each layer improves data separation at a constant geometric rate, and its emergence is observed in a collection of network architectures and datasets during training. This law offers practical guidelines for designing architectures, improving model robustness and out-of-sample performance, as well as interpreting the predictions.

2.
Eur Radiol ; 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38869639

RESUMEN

OBJECTIVES: To assess MR-based radiomic analysis in preoperatively discriminating small (< 2 cm) pancreatic ductal adenocarcinomas (PDACs) from neuroendocrine tumors (PNETs). METHODS: A total of 197 patients (146 in the training cohort, 51 in the validation cohort) from two centers were retrospectively collected. A total of 7338 radiomics features were extracted from T2-weighted, diffusion-weighted, T1-weighted, arterial phase, portal venous phase and delayed phase imaging. The optimal features were selected by the Mann-Whitney U test, Spearman's rank correlation test and least absolute shrinkage and selection operator method and used to construct the radiomic score (Rad-score). Conventional radiological and clinical features were also assessed. Multivariable logistic regression was used to construct a radiological model, a radiomic model and a fusion model. RESULTS: Nine optimal features were identified and used to build the Rad-score. The radiomic model based on the Rad-score achieved satisfactory results with AUCs of 0.905 and 0.930, sensitivities of 0.780 and 0.800, specificities of 0.906 and 0.952 and accuracies of 0.836 and 0.863 for the training and validation cohorts, respectively. The fusion model, incorporating CA19-9, tumor margins, pancreatic duct dilatation and the Rad-score, exhibited the best performance with AUCs of 0.977 and 0.941, sensitivities of 0.914 and 0.852, specificities of 0.954 and 0.950, and accuracies of 0.932 and 0.894 for the training and validation cohorts, respectively. CONCLUSIONS: The MR-based Rad-score is a novel image biomarker for discriminating small PDACs from PNETs. A fusion model combining radiomic, radiological and clinical features performed very well in differentially diagnosing these two tumors. CLINICAL RELEVANCE STATEMENT: A fusion model combining MR-based radiomic, radiological, and clinical features could help differentiate between small pancreatic ductal adenocarcinomas and pancreatic neuroendocrine tumors. KEY POINTS: Preoperatively differentiating small pancreatic ductal adenocarcinomas (PDACs) and pancreatic neuroendocrine tumors (PNETs) is challenging. Multiparametric MRI-based Rad-score can be used for discriminating small PDACs from PNETs. A fusion model incorporating radiomic, radiological, and clinical features differentiated small PDACs from PNETs well.

3.
Proc Natl Acad Sci U S A ; 118(43)2021 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-34675075

RESUMEN

In this paper, we introduce the Layer-Peeled Model, a nonconvex, yet analytically tractable, optimization program, in a quest to better understand deep neural networks that are trained for a sufficiently long time. As the name suggests, this model is derived by isolating the topmost layer from the remainder of the neural network, followed by imposing certain constraints separately on the two parts of the network. We demonstrate that the Layer-Peeled Model, albeit simple, inherits many characteristics of well-trained neural networks, thereby offering an effective tool for explaining and predicting common empirical patterns of deep-learning training. First, when working on class-balanced datasets, we prove that any solution to this model forms a simplex equiangular tight frame, which, in part, explains the recently discovered phenomenon of neural collapse [V. Papyan, X. Y. Han, D. L. Donoho, Proc. Natl. Acad. Sci. U.S.A. 117, 24652-24663 (2020)]. More importantly, when moving to the imbalanced case, our analysis of the Layer-Peeled Model reveals a hitherto-unknown phenomenon that we term Minority Collapse, which fundamentally limits the performance of deep-learning models on the minority classes. In addition, we use the Layer-Peeled Model to gain insights into how to mitigate Minority Collapse. Interestingly, this phenomenon is first predicted by the Layer-Peeled Model before being confirmed by our computational experiments.


Asunto(s)
Aprendizaje Profundo , Redes Neurales de la Computación , Heurística Computacional , Bases de Datos Factuales/estadística & datos numéricos , Humanos , Dinámicas no Lineales , Procesos Estocásticos
4.
Wound Repair Regen ; 31(4): 489-499, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37129099

RESUMEN

Immunosuppressive medications, which interfere with the activation and proliferation of T and B cells, increase the risk of wound healing complications. To address it, this study aimed to validate the feasibility of drug suspending during wound healing, whilst exploring the mechanisms exerted by T cells, which are important in the wound healing process. For this, a mouse skin wound model was set up. Tacrolimus (FK506) and fingolimod (FTY720) were both administered intraperitoneally prior to wounding to inhibit the T cell activation and migration, respectively. Flow-cytometric analysis subsequently revealed the functional T cell subtypes detected during the healing process. A CD8a antibody was also administered to deplete CD8+ T cells in vivo to verify their specific function. It was found that FK506 or FTY720 administration delayed the early phase of wound healing by reducing collagen production, which was also supported by the downregulation of col1a1, col3a1 and tgfb1. However, there was no significant difference in the total healing period. Both spleen- and skin-derived CD8+ T cells were proliferated and activated after injury without intervention, whereas CD4+ T cells showed no significant changes. Furthermore, selectively depleting CD8+ T cells retarded the healing process by downregulating collagen production-associated genes (col1a1, col3a1, tgfß1 and en1) and proteins (collagen type 1 and 3). In addition, the CD8a antibody decreased the expression of genes lta, tnfa, il13 and il13ra, and protein interleukin-13Rα. In conclusion, suspending immunosuppressive drugs during wound healing was shown to be feasible through restraining the migration of activated T cells. CD8+ T cells represented the primary functional subtype positively associated with wound healing.


Asunto(s)
Linfocitos T CD8-positivos , Cicatrización de Heridas , Ratones , Animales , Linfocitos T CD8-positivos/metabolismo , Tacrolimus/farmacología , Tacrolimus/metabolismo , Preparaciones Farmacéuticas/metabolismo , Clorhidrato de Fingolimod/farmacología , Clorhidrato de Fingolimod/uso terapéutico , Colágeno/metabolismo , Terapia de Inmunosupresión
5.
BMC Endocr Disord ; 23(1): 99, 2023 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-37143054

RESUMEN

BACKGROUND: The optimal therapeutic approach for cystic prolactinomas remains unclear. This study aimed to evaluate the remission rates of prolactinoma patients after surgical treatment and the risk factors affecting postoperative remission in cystic prolactinoma patients. METHODS: The clinical data were retrospectively compiled from 141 patients with prolactinomas (including 41 cases of cystic prolactinomas, 21 cases of solid microprolactinomas and 79 cases of solid macroprolactinomas) who underwent transsphenoidal surgery (TSS) between April 2013 and October 2021 at the First Affiliated Hospital of Sun Yat-sen University. RESULTS: Early postoperative remission was achieved in 65.83% (n = 27/41) of cystic prolactinomas, 80.95% (n = 17/21) of solid microprolactinomas and 40.51% (n = 32/79) of solid macroprolactinomas. The mean length of follow up in all patients was 43.95 ± 2.33 months (range: 6-105 months). The follow-up remission rates were 58.54%, 71.43% and 44.30% in cystic, solid micro- and solid macroprolactinomas, respectively. For cystic prolactinomas, the early postoperative remission rates in the patients with preoperative dopamine agonists (DA) treatment were significantly higher than those without preoperative DA treatment (p = 0.033), but the difference in the follow-up remission rates between these two groups was not significant (p = 0.209). Multivariate stepwise logistic regression analysis indicated that tumor size and preoperative prolactin (PRL) levels < 200 ng/ml were independent predictors for early postoperative remission in cystic prolactinomas. CONCLUSION: For cystic prolactinomas, tumor size and preoperative PRL levels were independent predictors of early postoperative remission. Preoperative DA therapy combined with TSS may be more beneficial to cystic prolactinoma patients.


Asunto(s)
Neoplasias Hipofisarias , Prolactinoma , Humanos , Prolactinoma/tratamiento farmacológico , Prolactinoma/cirugía , Estudios Retrospectivos , Neoplasias Hipofisarias/cirugía , Neoplasias Hipofisarias/tratamiento farmacológico , Resultado del Tratamiento , Prolactina , Agonistas de Dopamina/uso terapéutico
6.
Sensors (Basel) ; 22(13)2022 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-35808288

RESUMEN

Scientific injection molding technologies involve the integration and collaboration of cyber-physical systems and smart manufacturing. In order to achieve adaptive process control and production optimization, injection molding systems with real-time sensing have gradually become the development- and application-trend of smart injection molding. At the same time, this technology is a highly non-linear process in which many factors affect the product quality during long-run fabrication processes. Therefore, in order to grasp changes in the characteristics of plastic materials and product quality monitoring, the injection process has become an important research topic. We installed sensors in the molding machine (injection barrel, nozzle, and mold-cavity) to collect the melting pressure and used different materials (semi-crystalline and amorphous polymer; the melting-fill-index (MFI) is unified to 14.5 ± 0.5 g/10 min) to explore the influences of melting pressure variation and its viscosity index on the quality characteristics of molded products. The experiment reveals that a combination of barrel, nozzle, and mold-cavity sensing on the melt-pressure trend-based injection process-control incorporated with viscosity index monitoring can confirm the weight and shrinkage variation of the injection product. At the same time, the pressure and viscosity index value measured and calculated during the melt-filling of two materials with similar MI resulted in significant variations in the amorphous polymer. This study showed the possibility of mastering and controlling the rheology (barrel position) and shrinkage properties of polymers and successful application in various product-quality monitoring platforms.


Asunto(s)
Polímeros , Polímeros/química , Reología , Viscosidad
7.
J Reconstr Microsurg ; 38(9): 703-710, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35292954

RESUMEN

BACKGROUND: Ischemic preconditioning of the forehead flap prior to pedicle division helps to improve angiogenesis. Clamping the pedicle by a clamped rubber band with vessel forceps is often clinically applied. However, the severe pain and unstable blocking effect influenced the preconditioning process. In this study, we described an innovative device designed for ischemic preconditioning and compared its efficacy with the clamped rubber band. METHODS: The device consists of a self-locking nylon cable tie with a buckle and a rubber tube. The rubber tube is fed over the cable tie to act as a soft outer lining and the cable tie is tightened across the pedicle to block the perfusion for ischemic preconditioning. This device and the standard clamped rubber band were applied respectively before division surgery. The constriction effect, reliability, reproducibility, and the patients' pain tolerance were compared. RESULTS: A total of 20 forehead flaps were included. The cable tie had less incidence of loosening (7.7% vs. 16.6%, p < 0.05) and maintained the pressure more effectively. The pain score for the nylon cable tie was significantly lower than the clamped rubber band (4.25 ± 1.02 vs. 6.75 ± 1.12, p < 0.05), especially for 10 pediatric patients (4.50 ± 0.85 vs. 8.10 ± 1.20, p < 0.01). All 20 pedicles were successfully divided at 19 to 22 days with no surgical complications. CONCLUSION: Compared with the clamped rubber band, the cable tie produces a more reliable and reproducible ischemic preconditioning effect. It is also better tolerated by the patients. Therefore, we recommend using the nylon cable tie as the preferred device for ischemic preconditioning of the forehead flap.


Asunto(s)
Frente , Precondicionamiento Isquémico , Humanos , Niño , Frente/cirugía , Reproducibilidad de los Resultados , Nylons , Dolor
8.
Environ Sci Technol ; 54(8): 5031-5040, 2020 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-32204592

RESUMEN

As the earth's third most abundant element with various industrial applications, aluminum (Al) has received increasing concerns over its potential adverse health effects. Although Al exposure has been suggested to increase the risks of type 2 diabetes, little has been done to explore Al exposure in pregnant women and potential impact on the incidence of gestational diabetes mellitus (GDM). Our present study demonstrated positive associations between Al concentrations in maternal plasma collected in the first trimester of pregnancy and GDM risks (Ptrend < 0.001) based on a nested case-control study from Wuhan, China, including 305 GDM cases and 305 healthy controls. The highest tertile of plasma Al concentrations corresponded to an odds ratio of 4.03 (95% confidence interval: [2.14, 7.58]) relative to the lowest tertile, after the adjustment for established GDM risk factors and other plasma metals. We also observed significant correlations between plasma Al and several plasma polyunsaturated fatty acids (PUFA; e.g., linoleic acid 18:2 n-6) levels. In addition, mediation effects on the associations of Al exposure with GDM risks were observed for n-6 PUFAs (estimated mediation percentage: 48.3%) and total PUFAs (48.9%). Our study is not only by far the largest study of its kind to demonstrate maternal Al exposure and the association with GDM risks, but it also offers an insight into the potential mediation roles of n-6 PUFAs in an epidemiological setting. These findings contribute to a better understanding of perinatal Al exposure and GDM risks.


Asunto(s)
Diabetes Mellitus Tipo 2 , Diabetes Gestacional , Aluminio , Estudios de Casos y Controles , China , Ácidos Grasos Omega-6 , Ácidos Grasos Insaturados , Femenino , Humanos , Embarazo
9.
J Reconstr Microsurg ; 34(2): 77-86, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28992648

RESUMEN

BACKGROUND: The vascularization of the distal portions of transferred tissue represents the most critical factor in the success of reconstructive surgery. In recent years, indocyanine green (ICG) fluorescence imaging techniques have been applied during surgery to evaluate flap perfusion. However, this investigation has found that there is little consensus regarding the standard dose of ICG as well as the pre-operative requirements of ICG allergy testing. The aim of this study is to summarize the applications of ICG to tissue transfers and safe dosing practices and to provide insight to the possible adverse effects of ICG on flap surgery with the goal of helping clinicians apply ICG safely and efficiently to tissue transfer procedures. METHODS: A literature search was performed using, Wiley InterScience, and Springer with the key words, 'Flap,' 'indocyanine green,' 'surgery,' and related mesh words for all publications between 2005 and 2015. Title and abstract screening was performed using predefined in- and exclusion criteria. RESULTS: Seventy-three articles were included. These were classified as "application of ICG in flap surgery" and "the security of applying ICG in flap surgery". CONCLUSIONS: ICG fluorescence imaging preoperatively facilitates the detection of perforators in tissue flaps with thickness <20 mm, aids in the evaluation of flap microcirculation and perfusion, and allows surgeons to select dominant cutaneous nerves while evaluating the quality of vascular anastomoses and locating thromboses. The literature also concluded that potential allergic reactions to ICG should be taken into consideration.


Asunto(s)
Colorantes , Verde de Indocianina , Microcirculación/fisiología , Procedimientos de Cirugía Plástica/métodos , Colgajos Quirúrgicos/trasplante , Angiografía con Fluoresceína/métodos , Humanos , Imagen de Perfusión/métodos , Colgajos Quirúrgicos/irrigación sanguínea
10.
Biochem J ; 465(2): 315-23, 2015 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-25317587

RESUMEN

Menin regulates distinct cellular functions by regulating gene transcription through its interaction with partner transcription factors, but the exact mechanisms that control menin levels remain largely unknown. In the present study we report that Men1 mRNA, encoding menin, is a novel target of miR-29b and that miR-29b/Men1 mRNA association regulates menin expression post-transcriptionally in rat intestinal epithelial cells (IECs). Overexpression of a miR-29b precursor lowered the levels of Men1 mRNA modestly, but reduced new synthesis of menin robustly; conversely, antagonism of miR-29b enhanced menin protein synthesis and steady-state levels. The repressive effect of miR-29b on menin expression was mediated through a single binding site in the coding region of Men1 mRNA, because point mutation of this site prevented miR-29b-induced repression of menin translation. Increasing cellular polyamines due to overexpression of ornithine decarboxylase (ODC) enhanced menin translation by reducing miR-29b, whereas polyamine depletion by inhibiting ODC increased it, thus suppressing menin expression. Moreover, an increase in menin abundance in an miR-29b-silenced population of IECs led to increased sensitivity to apoptosis, which was prevented by silencing menin. These findings indicate that miR-29b represses translation of Men1 mRNA, in turn affecting intestinal epithelial homoeostasis by altering IEC apoptosis.


Asunto(s)
Regulación de la Expresión Génica/fisiología , Mucosa Intestinal/metabolismo , MicroARNs/metabolismo , Biosíntesis de Proteínas/fisiología , ARN Mensajero/metabolismo , Factores de Transcripción/biosíntesis , Animales , Apoptosis/fisiología , Poliaminas Biogénicas/metabolismo , Línea Celular , Silenciador del Gen , MicroARNs/genética , Ornitina Descarboxilasa/genética , Ornitina Descarboxilasa/metabolismo , ARN Mensajero/genética , Ratas , Factores de Transcripción/genética
11.
J Reconstr Microsurg ; 32(5): 411-4, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27128261

RESUMEN

Background Reconstruction of the central facial subunits is a complex and challenging task. In cases in which both the nasal and upper lip subunits are involved, a technique that can reconstruct both aesthetic units with tissue of similar color and texture from a single donor site will be ideal. In this article we present our experience with the bipedicled preexpanded forehead flap for simultaneous nasal and upper lip resurfacing. Patients and Methods Between January 2012 and January 2015 we used this technique in the simultaneous reconstruction of total nasal and upper lip subunits in five patients. All cases were for burns scar resurfacing. Results Good aesthetic results were achieved in each of our five cases to date and no complications were encountered. All donor sites closed primarily with aesthetically pleasing well-concealed linear scars. In all cases small modifications such as philtral shaping and further flap thinning were performed under local anesthesia between 6 and 12 months postoperatively Conclusion The preexpanded forehead flap provides an unparalleled color and texture match when it comes to facial resurfacing. When both total nasal and upper lip resurfacings are required, it is possible to achieve this in a single sitting from a single donor site by using a bipedicled preexpanded forehead flap.


Asunto(s)
Traumatismos Faciales/cirugía , Frente/cirugía , Labio/cirugía , Nariz/cirugía , Procedimientos de Cirugía Plástica , Colgajos Quirúrgicos , Adolescente , Adulto , Quemaduras/patología , Quemaduras/cirugía , Cicatriz/patología , Cicatriz/cirugía , Estética , Traumatismos Faciales/patología , Femenino , Humanos , Labio/lesiones , Masculino , Persona de Mediana Edad , Nariz/lesiones , Resultado del Tratamiento , Adulto Joven
12.
Aesthet Surg J ; 35(5): 600-10, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25825422

RESUMEN

BACKGROUND: Research has investigated the decrease in human skin sebum after the application of botulinum toxin. Few studies of the mechanism and objective assessments of this phenomenon have been conducted and the correlation between the sebum production and injection dosages or techniques remains unclear. OBJECTIVES: We prospectively investigated the sebum regulation and its gradient around the injection site in patients who received intramuscular injections of botulinum toxin A (BTX-A) for forehead rhytides, comparing two injection doses. METHODS: Forty-two female volunteers with rhytides on the forehead region were randomly assigned to receive 10 or 20 units of BTX-A, which was administered in five standard injection sites. The baseline and post-treatment sebum production was measured using a Sebumeter. RESULTS: Treatment with BTX-A exhibited significant sebum alteration at the injection site of both groups, with a sebum gradient surrounding the injection point. The efficacy did not improve at higher injection doses, with the four-unit regimen generally not being more potent than the two-unit regimen. The sebum production recovered to normal levels at the 16 week follow-up for both treatment groups, indicating that a higher dosage (four units) did not result in a longer duration until relapse compared with the two-unit dose. CONCLUSIONS: We determined that the sebum production has a positive correlation with the distance away from the injection point. Intramuscular injection of BTX-A significantly reduces sebum production at the injection site but increases the sebum production of the surrounding skin at a radius of 2.5 cm at the 2, 4, and 8 week follow-ups. LEVEL OF EVIDENCE: 2 Therapeutic.


Asunto(s)
Toxinas Botulínicas Tipo A/administración & dosificación , Fármacos Neuromusculares/administración & dosificación , Sebo/metabolismo , Envejecimiento de la Piel/efectos de los fármacos , Adulto , Toxinas Botulínicas Tipo A/efectos adversos , China , Método Doble Ciego , Femenino , Frente , Humanos , Inyecciones Intramusculares , Persona de Mediana Edad , Fármacos Neuromusculares/efectos adversos , Estudios Prospectivos , Factores de Tiempo , Resultado del Tratamiento
13.
Aesthetic Plast Surg ; 38(6): 1116-30, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25338712

RESUMEN

BACKGROUND: There are many methods of measuring the breast and their clinical applications are well described in the literature. However, there has been no attempt to compare these various methods to allow the user to have a broad overview of the subject. The authors have attempted to summarise all the available methods to measure the breast in this article to provide a useful reference for all. METHODS: A comprehensive literature search of PubMed was performed, and the resulting articles were screened and reviewed. The data regarding the methods' mechanism, reliability, time and cost were evaluated and compared. RESULTS: A total of 74 articles dating from 1970 to 2013 were included in this study. All of the methods can be classified into those that measure (1) volume, (2) shape and (3) surface area. Each category consists of several methods that work through different mechanisms and they vary in their reliability and feasibility. Based on their mechanism, the volume measurement methods were further grouped into the natural shape methods, the stereological method, the geometrical methods and the mathematical modelling method. CONCLUSIONS: More objective breast evaluation can be achieved if all three dimensions (volume, shape and surface area) are considered. In the volume measurements, 3D modelling and the MRI are the most reliable tools. Linear measurement (geometry) and mathematical modelling are less accurate but are more economical. In the shape measurements, besides the traditional linear measurement, 3D methods that can deliver colour-coded maps and Swanson's 2D photographic measurement system are capable of depicting and tracking breast shape changes after surgery. Although the surface area metric has not been used extensively, it has potential in clinical and research applications. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.


Asunto(s)
Antropometría/métodos , Mama/anatomía & histología , Medicina Basada en la Evidencia , Algoritmos , Puntos Anatómicos de Referencia , Mama/fisiología , Densitometría/métodos , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética/métodos
14.
Int J Mol Sci ; 15(12): 22786-800, 2014 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-25501333

RESUMEN

Applying Ethosomal Gels (EGs) in transdermal drug delivery systems has evoked considerable interest because of their good water-solubility and biocompatibility. However, there has not been an explicit description of applying EGs as a vehicle for hypertrophic scars treatment. Here, a novel transdermal EGs loaded with 5-fluorouracil (5-FU EGs) was successfully prepared and characterized. The stability assay in vitro revealed that 5-FU EGs stored for a period of 30 days at 4 ± 1 °C had a better size stability than that at 25 ± 1 °C. Furthermore, using confocal laser scanning microscopy, EGs labeled with Rhodamine 6 G penetrated into the deep dermis of the hypertrophic scar within 24 h in the rabbit ear hypertrophic model suggested that the EGs were an optional delivery carrier through scar tissues. In addition, the value of the Scar Elevation Index (SEI) of 5-FU EGs group in the rabbit ear scar model was lower than that of 5-FU Phosphate Buffered Saline gel and Control groups. To conclude, these results suggest that EGs delivery system loaded 5-fluorouracil is a perfect candidate drug for hypertrophic scars therapy in future.


Asunto(s)
Antimetabolitos/administración & dosificación , Cicatriz Hipertrófica/tratamiento farmacológico , Fluorouracilo/administración & dosificación , Inmunosupresores/administración & dosificación , Administración Cutánea , Animales , Línea Celular , Química Farmacéutica , Cicatriz Hipertrófica/genética , Cicatriz Hipertrófica/metabolismo , Cicatriz Hipertrófica/patología , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Modelos Animales de Enfermedad , Estabilidad de Medicamentos , Femenino , Geles , Humanos , Liposomas , Conejos
15.
Cell Transplant ; 33: 9636897241233040, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38400732

RESUMEN

Spinal cord injury (SCI) severely affects the quality of life and autonomy of patients, and effective treatments are currently lacking. Autophagy, an essential cellular metabolic process, plays a crucial role in neuroprotection and repair after SCI. Glycoprotein non-metastatic melanoma protein B (GPNMB) has been shown to promote neural regeneration and synapse reconstruction, potentially through the facilitation of autophagy. However, the specific role of GPNMB in autophagy after SCI is still unclear. In this study, we utilized the spinal cord transection method to establish SCI rats model and overexpressed GPNMB using adenoviral vectors. We assessed tissue damage using hematoxylin and eosin (H&E) and Nissl staining, and observed cell apoptosis using TUNEL staining. We evaluated the inflammatory response by measuring inflammatory factors using enzyme-linked immunosorbent assay (ELISA). In addition, we measured reactive oxygen species (ROS) levels using 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA), and assessed oxidative stress levels by measuring malondialdehyde (MDA) and glutathione (GSH) using ELISA. To evaluate autophagy levels, we performed immunofluorescence staining for the autophagy marker Beclin-1 and conducted Western blot analysis for autophagy-related proteins. We also assessed limb recovery through functional evaluation. Meanwhile, we induced cell injury using lipopolysaccharide (LPS) and added an autophagy inhibitor to verify the impact of GPNMB on SCI through autophagy modulation. The results demonstrated that GPNMB alleviated the inflammatory response, reduced oxidative stress levels, inhibited cell apoptosis, and promoted autophagy following SCI. Inhibiting autophagy reversed the effects of GPNMB. These findings suggest that GPNMB promotes neural injury repair after SCI, potentially through attenuating the inflammatory response, reducing oxidative stress, and inhibiting cell apoptosis.


Asunto(s)
Melanoma , Receptores Fc , Traumatismos de la Médula Espinal , Animales , Humanos , Ratas , Apoptosis , Autofagia , Glutatión/metabolismo , Glicoproteínas/farmacología , Melanoma/metabolismo , Melanoma/patología , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/farmacología , Calidad de Vida , Ratas Sprague-Dawley , Recuperación de la Función/fisiología , Médula Espinal/patología , Traumatismos de la Médula Espinal/patología
16.
Kaohsiung J Med Sci ; 40(2): 161-174, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37873881

RESUMEN

Temozolomide (TMZ) resistance presents a significant challenge in the treatment of gliomas. Although lysine demethylase 4A (KDM4A) has been implicated in various cancer-related processes, its role in TMZ resistance remains unclear. This study aims to elucidate the contribution of KDM4A to TMZ resistance in glioma cells and its potential implications for glioma prognosis. We assessed the expression of KDM4A in glioma cells (T98G and U251MG) using qRT-PCR and Western blot assays. To explore the role of KDM4A in TMZ resistance, we transfected siRNA targeting KDM4A into drug-resistant glioma cells. Cell viability was assessed using the CCK-8 assay and the TMZ IC50 value was determined. ChIP assays were conducted to investigate KDM4A, H3K9me3, and H3K36me3 enrichment on the promoters of ROCK2 and HUWE1. Co-immunoprecipitation confirmed the interaction between HUWE1 and ROCK2, and we examined the levels of ROCK2 ubiquitination following MG132 treatment. Notably, T98G cells exhibited greater resistance to TMZ than U251MG cells, and KDM4A displayed high expression in T98G cells. Inhibiting KDM4A resulted in decreased cell viability and a reduction in the TMZ IC50 value. Mechanistically, KDM4A promoted ROCK2 transcription by modulating H3K9me3 levels. Moreover, disruption of the interaction between HUWE1 and ROCK2 led to reduced ROCK2 ubiquitination. Inhibition of HUWE1 or overexpression of ROCK2 counteracted the sensitization effect of si-KDM4A on TMZ responsiveness in T98G cells. Our findings highlight KDM4A's role in enhancing TMZ resistance in glioma cells by modulating ROCK2 and HUWE1 transcription and expression through H3K9me3 and H3K36me3 removal.


Asunto(s)
Neoplasias Encefálicas , Glioma , Humanos , Temozolomida/farmacología , Temozolomida/uso terapéutico , Histonas/metabolismo , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Antineoplásicos Alquilantes/farmacología , Antineoplásicos Alquilantes/uso terapéutico , Línea Celular Tumoral , Glioma/genética , Metilación , Resistencia a Antineoplásicos/genética , Histona Demetilasas con Dominio de Jumonji/genética , Histona Demetilasas con Dominio de Jumonji/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Quinasas Asociadas a rho/genética , Quinasas Asociadas a rho/metabolismo
17.
J Reconstr Microsurg ; 29(4): 255-62, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23322538

RESUMEN

BACKGROUND: The achievement of a normal-appearing face after surgical resurfacing remains an elusive goal. This is due in part to insufficient color matching, restoration of contours, and the persistence of visible scars. Flap prefabrication is a staged procedure that provides an independent axial blood supply to local expanded tissues. We describe a new reconstructive alternative with superior reconstructive surgical options for facial resurfacing that better matches damaged or discarded facial tissues. METHODS: A superficial temporal fascial flap was harvested as the vascular supply of the prefabricated neck flap and located in a subcutaneous neck pocket over a tissue expander. After a 5-month period for expansion and maturation, the prefabricated skin flap was raised, islanded, and rotated to resurface the facial defect. RESULTS: Four patients with hemifacial postburn contracture and two patients affected by hemifacial vascular malformations aged 17 to 42 years (mean 29 years) were successfully treated with no major complication after a mean period of 15 months. CONCLUSION: Prefabricated neck-expanded skin flap demonstrated an excellent color and texture match with facial skin that surrounded the repair sites, and optimal aesthetic results were obtained. Importantly, facial expression was completely maintained due to thinness and pliability of the rotated skin.


Asunto(s)
Cara/cirugía , Procedimientos de Cirugía Plástica/métodos , Trasplante de Piel/métodos , Colgajos Quirúrgicos/trasplante , Expansión de Tejido/métodos , Adolescente , Adulto , Quemaduras/cirugía , Contractura/cirugía , Estética , Cara/irrigación sanguínea , Expresión Facial , Traumatismos Faciales/cirugía , Fascia/irrigación sanguínea , Fascia/trasplante , Femenino , Estudios de Seguimiento , Humanos , Cuello/cirugía , Complicaciones Posoperatorias , Pigmentación de la Piel/fisiología , Colgajos Quirúrgicos/irrigación sanguínea , Arterias Temporales/trasplante , Dispositivos de Expansión Tisular , Recolección de Tejidos y Órganos/métodos , Malformaciones Vasculares/cirugía , Adulto Joven
18.
Polymers (Basel) ; 15(3)2023 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-36771911

RESUMEN

The injection-molding process is a non-linear process, and the product quality and long-term production stability are affected by several factors. To stabilize the product quality effected by these factors, this research establishes a standard process parameter setup procedure and an adaptive process control system based on the data collected by a nozzle pressure sensor and a tie-bar strain gauge to achieve this goal. In this research, process parameters such as the V/P switchover point, injection speed, packing pressure, and clamping force are sequentially optimized based on the characteristics of the pressure profile. After the optimization process, this research defines the standard quality characteristics through the optimized process parameters and combines it with the adaptive process control system in order to achieve the purpose of automatic adjustment of the machine and maintain high-quality production. Finally, three different viscosity materials are used to verify the effectiveness of the optimization procedure and the adaptive process control system. With the system, the variation of product weight was reduced to 0.106%, 0.092%, and 0.079%, respectively.

19.
ACS Appl Bio Mater ; 6(12): 5854-5863, 2023 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-37948755

RESUMEN

It is challenging to treat peripheral nerve injury (PNI) clinically. As the gold standard for peripheral nerve repair, autologous nerve grafting remains a critical limitation, including tissue availability, donor-site morbidity, immune rejection, etc. Recently, conductive hydrogels (CHs) have shown potential applications in neural bioengineering due to their good conductivity, biocompatibility, and low immunogenicity. Herein, a hybrid electrically conductive hydrogel composed of acrylic acid derivatives, gelatin, and heparin with sustained nerve growth factor (NGF) release property was developed. The rat sciatic nerve injury (SNI) model (10 mm long segment defect) was used to investigate the efficacy of these hydrogel conduits in facilitating peripheral nerve repair. The results showed that the hydrogel conduits had excellent conductivity, mechanical properties, and biocompatibility. In addition, NGF immobilized in the hydrogel conduits had good sustained release characteristics. Finally, functional recovery and electrophysiological evaluations, together with histological analysis, indicated that the hydrogel conduits immobilizing NGF had superior effects on motor recovery, axon growth, and remyelination, thereby significantly accelerating the repairing of the sciatic nerve. This study demonstrated that hybrid electrically conductive hydrogels with local NGF release could be effectively used for PNI repair.


Asunto(s)
Hidrogeles , Traumatismos de los Nervios Periféricos , Ratas , Animales , Hidrogeles/farmacología , Factor de Crecimiento Nervioso/farmacología , Factor de Crecimiento Nervioso/metabolismo , Nervio Ciático/patología , Nervio Ciático/fisiología , Traumatismos de los Nervios Periféricos/terapia , Regeneración Nerviosa/fisiología
20.
Cell Death Discov ; 9(1): 310, 2023 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-37620304

RESUMEN

Reprogramming of metabolic genes and subsequent alterations in metabolic phenotypes occur widely in malignant tumours, including glioblastoma (GBM). FOXM1 is a potent transcription factor that plays an oncogenic role by regulating the expression of many genes. As a SET domain containing protein, SET7 is a protein lysine methyltransferase which monomethylates histone proteins and other proteins. The epigenetic modification of histones regulates gene expressions by epigenetically modifying promoters of DNAs and inter vening in tumor development. Activation of FASN increased de novo fatty acid (FA) synthesis, a hallmark of cancer cells. Here, we report that FOXM1 may directly promote the transcription of SET7 and activate SET7-H3K4me1-FASN axis, which results in the maintenance of de novo FA synthesis.

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