Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
Nanoscale Horiz ; 9(5): 718-730, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38533801

RESUMEN

Chemical synthesis typically yields the most thermodynamically stable ordered arrangement, a principle also governing surface synthesis on an atomically level two-dimensional (2D) surface, fostering the creation of structured 2D formations. The linear connection arising from energetically stable chemical bonding precludes the generation of a 2D random network comprised of one-dimensional (1D) convoluted stripes through on-surface synthesis. Nonetheless, we underscored that on-surface synthesis possesses the capability not solely to fashion a 2D ordered linear network but also to fabricate a winding 2D network employing a precursor with a soft ring and intermediate state bonding within the Ullmann reaction. Here, on-surface synthesis was exhibited on Cu(111) employing a 2D self-assembled monolayer array of 4,4',5,5'-tetrabromodibenzo[18]crown-6 ether (BrCR) precursors. These precursors were purposefully structured, with a crown ether ring at the core and Br atoms positioned at the head and tail ends, facilitating preferential connections along the elongated axis to foster a 1D stripe configuration. We illustrate how adjustments in the quantities of the intermediate state, serving as a primary linkage, can yield a labyrinthine, convoluted winding 2D network of stripes. The progression of growth, underlying mechanisms, and electronic structures were scrutinized using an ultrahigh vacuum low-temperature scanning tunneling microscopy and spectroscopy (STM/STS) setup combined with density functional theory (DFT) calculations. This experimental evidence opens a novel functionality in leveraging on-surface synthesis for the formation of a 2D random network. This discovery holds promise as a pioneering constituent in the construction of a ring host supramolecule, augmenting its capability to ensnare guest atoms, molecules, or ions.

2.
J Am Chem Soc ; 145(39): 21378-21386, 2023 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-37733877

RESUMEN

Stimuli-responsive molecular crystals have attracted considerable attention as promising smart materials with applications in various fields such as sensing, actuation, and optoelectronics. Understanding the structure-mechanical property relationships, however, remains largely unexplored when it comes to functionalizing these organic crystals. Here, we report three polymorphic crystals (Forms A, B, and C) formed by the non-threaded complexation of a dibenzo[18]crown-6 (DB18C6) ether ring and an azobenzene-based ammonium cation, each exhibiting distinct thermal phase transitions, photoinduced deformations, and mechanical behavior. Structural changes on going from Form A to Form B and from Form C to Form B during heating and cooling, respectively, are observed by single-crystal X-ray crystallography. Form A shows photoinduced reversible bending, whereas Form B exhibits isotropic expansion. Form C displays uniaxial negative expansion with a remarkable increase of 44% in thickness under photoirradiation. Force measurements and nanoindentation reveal that the soft crystals of Form A with a low elastic modulus demonstrate a significant photoresponse, attributed to the non-threaded molecular structure, which permits flexibility of the azobenzene unit. This work represents a significant advance in the understanding of the correlation between structure-thermomechanical and structure-photomechanical properties necessary for the development of multi-stimulus-responsive materials with tailored properties.

3.
ACS Appl Mater Interfaces ; 15(32): 38846-38856, 2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37537978

RESUMEN

This paper presents facile photoresponsive actuators comprising ferrocene as a guest chromophore and poly(butyl methacrylate) (PBMA) as a host matrix. The ferrocene-doped PBMA film exhibits mechanical expansion and contraction when a 445 nm laser is turned on and off, respectively. The photoresponsive film is attached by a commercially available acetylcellulose adhesive tape, which exhibits a bending motion that is controlled by turning the laser on and off. Thereafter, the double-layer film is employed to fabricate a table-shaped lifting machine (0.7 mg) that lifts a 10.5 mg object up and down by turning the laser on and off, respectively, and the mechanical force offered by the double-layer film is recorded. Additionally, the film is coated with gold and applied to an electric circuit that serves as a reversible photoresponsive switch. This film preparation technique is applied to other chromophores (e.g., Coumarin 343, Rhodamine 6G, Sudan Blue II, and Solvent Green 3) to independently control the motions of the films with 445, 520, and 655 nm lasers. The ferrocene-containing films also exhibit photoinduced healing from mechanical damage. Finally, the photoirradiation-accompanied morphological changes in the film are observed via small-angle X-ray scattering.

4.
J Formos Med Assoc ; 121(1 Pt 2): 395-401, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34120802

RESUMEN

BACKGROUND/PURPOSE: Redo operation for mitral valve surgery carries higher risks than first time cardiac surgery. The adhesion between sternum and heart, and also the complexity of second time operation make the redo operation more difficult. The robotic surgery carries some benefit in terms of magnification, assisted by the scope view and precise movement of the instruments. We compared the results of our robotic redo mitral valve surgeries with those of conventional re-sternotomy. METHODS: Medical records of patients who underwent redo mitral valve surgeries between 2012 and 2019 at our hospital were retrospectively analyzed. Demographic data, patients' medical histories, presenting symptoms, image analyses, echocardiogram data, operative procedures and postoperative clinical outcomes were collected through chart review. RESULTS: A total of 67 redo mitral valve surgeries, including 23 robotic and 44 re-sternotomy procedures were performed. There were no differences in age, previous operation times, and intervals to previous surgery. Comorbidities of both groups were similar. There was no surgical mortality in the robotic group, and it was 9.0% in the re-sternotomy group (p = 0.287). Operation time was shorter in the robotic group (176 vs. 321 min; robotic vs. re-sternotomy, p=0.0279). Blood transfusion was lower in the robotic group (1 vs. 2 units; robotic vs. re-sternotomy, p = 0.01189). The ventilation time, ICU stay time, and recheck bleeding rate were similar in both groups. CONCLUSION: In select patients, robotic redo mitral valve surgery is safe and feasible. It could offer low operative mortality. It is associated with shorter operative times, than re-sternotomy and provides equal immediate operative results.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Procedimientos Quirúrgicos Robotizados , Humanos , Válvula Mitral/cirugía , Estudios Retrospectivos , Esternotomía
5.
Chem Sci ; 12(11): 3871-3875, 2021 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-34163655

RESUMEN

This work describes unique molecular motions of ferrocene-containing interlocked molecules observed by single-crystal X-ray crystallography. The rotational flexibility of ferrocene is achieved using combinations of ferrocene-tethered ammonium and 30-membered ring dibenzo-crown ether. By contrast, ferrocene was locked in the complex with an 18-membered ring dibenzo-crown ether and CH2Cl2. When the complex was heated at 358 K, CH2Cl2 was removed from the complex, which led to drastic structural changes, including a semieclipsed-to-disordered transition of ferrocene and flipping of the dibenzo-crown ether.

6.
ACS Appl Mater Interfaces ; 12(44): 50002-50010, 2020 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-33089689

RESUMEN

This work describes the design and characterization of photoresponsive dynamic pseudorotaxane crystals composed of azobenzene and ferrocenyl groups in an ammonium cation axle component threaded through dibenzo[24]crown-8 ether rings. Pseudorotaxanes provide flexibility for cis and trans isomerization of azobenzene groups in a crystal state, enabling reversible bending motions under alternating 360 and 445 nm laser irradiation. For such bending motions, strained azobenzene structures were essential; these motifs were obtained by increasing the bulkiness of the substituents on the axle and ring molecules. In addition, the crystals showed photosalient effects, such as jumping motions, under 445 nm laser irradiation. These motions were assisted by the photoabsorption of the ferrocenyl group, which converted 445 nm laser light into heat. The maximum lifting weight accompanied by the photoinduced mechanical motion of a particular crystal was estimated to be 9600 times the crystal weight. These pseudorotaxane crystals exhibit promising features for applications in micro-nanometer-sized miniature mechanical devices.

7.
BMC Med Educ ; 20(1): 129, 2020 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-32345306

RESUMEN

BACKGROUND: Each year, more than 200 international dental graduates start U.S. specialty trainings to become specialists. It is unknown if their life satisfaction is associated with any dental career-related factor before residencies (e.g. dental school class rank, research experience, or private practice experience) and after residencies (e.g. staying in the U.S., teaching status, workplace, or board certification). This cross-sectional study aimed to identify these potential factors by surveying Taiwanese dental graduates who pursued U.S. residencies. METHODS: Life satisfaction was measured with a structured questionnaire, Satisfaction With Life Scale (SWLS), which includes five statements on a 5-point Likert scale. Online surveys were sent out to 290 Taiwanese dental graduates who were known to pursue U.S. residencies. T-test, one way analysis of variance, and multivariable adjusted generalized linear model (GLM) were used to assess the differences of mean SWLS scores from different variables. RESULTS: Surveys were completed by 158 dentists. Mean SWLS score of 125 specialists was higher (p = 0.0007) than the score of 33 residents. For the 125 specialists, multivariable adjusted GLM demonstrated better life satisfaction was positively associated with multiple independent factors, such as having research experience, being ranked in the top 26 ~ 50% of the class in dental school, starting U.S. residency within 4 years after dental school, starting residency before year 1996, and specializing in endodontics (vs. periodontics). Life satisfaction was not associated with any factors after residency (e.g. staying in the U.S. afterwards, teaching status, or workplace), but better mean life satisfaction score was significantly associated with being American specialty board certified (p < 0.001) for the specialists in the 26 ~ 75% of their class in dental school. For the 33 residents, better mean life satisfaction score was associated with better dental school class rank in both bivariate (p = 0.020) and multivariable adjusted GLM (p = 0.004) analyses. CONCLUSIONS: The life satisfaction of Taiwanese dental graduates pursuing U.S. residencies might be associated with some professional factors, such as research experience, dental school class rank, residency timing, specialty type, and specialty board certification. We hope our results may provide some objective information on making career decisions for international dental graduates/students who are preparing for U.S. residency.


Asunto(s)
Certificación/estadística & datos numéricos , Educación de Posgrado en Odontología/normas , Odontología General/educación , Internado y Residencia/normas , Satisfacción Personal , Pautas de la Práctica en Odontología/normas , Adulto , Selección de Profesión , Estudios Transversales , Femenino , Odontología General/normas , Humanos , Masculino , Facultades de Odontología/organización & administración , Especialidades Odontológicas/educación , Taiwán , Estados Unidos
8.
Biochim Biophys Acta Mol Cell Res ; 1866(8): 1282-1297, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30935967

RESUMEN

Fas-associated factor 1 (FAF1) was originally isolated as a Fas-associated factor and was subsequently found to interact with numerous other proteins that are involved in various cellular events including Fas-mediated apoptosis, nuclear factor (NF)-κB, Wnt/ß-catenin, and transforming growth factor (TGF)-ß signaling pathways, mineralocorticoid receptor (MR)-mediated transactivation, and ubiquitin-dependent processes. Herein, we defined two small ubiquitin-like modifier (SUMO)-interacting motifs (SIMs) within FAF1 and demonstrated to be crucial for transcriptional modulation of the MR. Our study demonstrated that the SIMs of FAF1 do not play a significant role in regulating its subcellular localization, Fas-mediated apoptosis, or NF-κB or Wnt/ß-catenin pathways. Remarkably, FAF1 interacts with the sumoylated MR and represses aldosterone-activated MR transactivation in a SIM-dependent manner. Moreover, silencing of endogenous FAF1 in cells resulted in an increase in the induction of MR target genes by aldosterone, indicating that FAF1 functions as an MR co-repressor. We further provide evidence to suggest that the mechanisms of FAF1/SIM-mediated MR transrepression involve inhibition of MR N/C interactions and promotion of MR polyubiquitination and degradation. Sumoylation has been linked to impacting of repressive properties on several transcription factors and cofactors. Our findings therefore provide mechanistic insights underlying SUMO-dependent transcriptional repression of the MR.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Receptores de Mineralocorticoides/metabolismo , Transcripción Genética , Proteínas Adaptadoras Transductoras de Señales/genética , Aldosterona/farmacología , Secuencias de Aminoácidos , Animales , Proteínas Reguladoras de la Apoptosis , Células COS , Chlorocebus aethiops , Células HEK293 , Células HeLa , Humanos , Transporte de Proteínas , Receptores de Mineralocorticoides/agonistas , Receptores de Mineralocorticoides/genética , Proteínas Modificadoras Pequeñas Relacionadas con Ubiquitina/genética , Proteínas Modificadoras Pequeñas Relacionadas con Ubiquitina/metabolismo , Sumoilación/efectos de los fármacos , Sumoilación/genética
9.
Ann Plast Surg ; 78(3 Suppl 2): S135-S138, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28166140

RESUMEN

BACKGROUND: Human cadaveric skin grafts are considered as the "gold standard" for temporary wound coverage because they provide a more conductive environment for natural wound healing. Lyophilization, packing, and terminal sterilization with gamma-ray can facilitate the application of cadaveric split-thickness skin grafts, but may alter the adhesion properties of the grafts. In a pilot study, we found that 500 Gy γ-irradiation seemed not to reduce the adherence between the grafts and wound beds. AIM AND OBJECTIVES: We conducted this experiment to compare the adherences of lyophilized, 500-Gy γ-irradiated skin grafts to that of lyophilized, nonirradiated grafts. MATERIALS AND METHODS: Pairs of wounds were created over the backs of Sprague- Dawley rats. Pairs of "lyophilized, 500-Gy γ-irradiated" and "lyophilized, nonirradiated" cadaveric split-thickness skin grafts were fixed to the wound beds. Adhesion strength between the grafts and the wound beds was measured and compared. RESULTS: On post-skin-graft day 7 and day 10, the adhesion strength of γ-irradiated grafts was greater than that of the nonirradiated grafts. CONCLUSIONS: Because lyophilized cadaveric skin grafts can be vascularized and the collagen of its dermal component can be remodeled after grafting, the superior adhesion strength of 500-Gy γ-irradiated grafts can be explained by the collagen changes from irradiation.


Asunto(s)
Adhesión Celular/efectos de la radiación , Liofilización , Trasplante de Piel/métodos , Piel/efectos de la radiación , Esterilización/métodos , Técnicas de Cierre de Heridas , Animales , Cadáver , Rayos gamma , Humanos , Proyectos Piloto , Ratas , Ratas Sprague-Dawley
10.
Ann Plast Surg ; 78(3 Suppl 2): S148-S152, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28129211

RESUMEN

BACKGROUND: Although tendon-exposed or bone-exposed wounds can be resurfaced with flaps, such surgeries may not be feasible in patients with poor general or local conditions. Biosynthetic artificial skin is an alternative for critical wound coverage. We designed a new artificial skin bilayer to close difficult wounds permanently. AIM AND OBJECTIVES: This study compares incorporation and wound contraction between silicone acellular porcine dermis (SAPD) and the Integra graft (Integra Life Sciences Corp., Billerica, Mass) in a rat model. MATERIALS AND METHODS: The SAPD was manufactured according to our previously described standard procedures. Integra grafts were obtained commercially. We included 24 male adult Sprague-Dawley rats and divided them into 2 groups. After creating a 3 × 4-cm full-thickness wound on the back, we transplanted the same-sized SAPD and Integra grafts onto the rat wounds. Autologous full-thickness skin (FTS) was grafted onto the acellular porcine dermal matrix (APDM) of the SAPD and the Integra dermal matrix (IDM) 2 weeks later. We measured the wound size and contraction rate of recipient wounds, studied the incorporation of FTS on the dermal matrix, and did pathological examination. Generalized estimating equations were used to assess the data from repeated wound and scar contraction measurements using SAS v9.2. RESULTS: The sizes of wounds of both groups decreased over time. No difference in wound contraction was observed between the SAPD and Integra groups at weeks 2, 4, or 6 after grafting. However, the contraction rates in both groups increased significantly. The pathological examination showed that the FTS was well incorporated in the APDM and IDM. The recipient wounds showed new vessels and cell infiltration in the new matrix, but no severe inflammation. Skin appendages were regenerating in the FTS. There was no rejection sign. CONCLUSIONS: Both SAPD and Integra are double-layered artificial skin products. Our results demonstrate that APDM and IDM are good templates and show excellent incorporation with autologous FTS graft. The results also demonstrated gradual wound contraction over time, but the contraction rate was not different between SAPD and Integra 6 weeks after grafting in a rat model.


Asunto(s)
Sulfatos de Condroitina/farmacología , Colágeno/farmacología , Trasplante de Piel/métodos , Técnicas de Cierre de Heridas , Cicatrización de Heridas/fisiología , Dermis Acelular , Animales , Cicatriz/patología , Contractura/patología , Modelos Animales de Enfermedad , Masculino , Ratas , Ratas Sprague-Dawley , Porcinos , Trasplante Autólogo
11.
Mol Ther ; 22(11): 1890-9, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25048216

RESUMEN

Mutations in fukutin-related protein (FKRP) gene cause a wide spectrum of disease phenotypes including the mild limb-girdle muscular dystrophy 2I (LGMD2I), the severe Walker-Warburg syndrome, and muscle-eye-brain disease. FKRP deficiency results in α-dystroglycan (α-DG) hypoglycosylation in the muscle and heart, which is a biochemical hallmark of dystroglycanopathies. To study gene replacement therapy, we generated and characterized a new mouse model of LGMD2I harboring the human mutation leucine 276 to isoleucine (L276I) in the mouse alleles. The homozygous knock-in mice (L276I(KI)) mimic the classic late onset phenotype of LGMD2I in both skeletal and cardiac muscles. Systemic delivery of human FKRP gene by AAV9 vector in the L276I(KI) mice, at either neonatal age or at the age of 9 months, rendered body wide FKRP expression and restored glycosylation of α-DG in both skeletal and cardiac muscles. FKRP gene therapy ameliorated dystrophic pathology and cardiomyopathy such as muscle degeneration, fibrosis, and myofiber membrane leakage, resulting in restoration of muscle and heart contractile functions. Thus, these results demonstrated that the treatment based on FKRP gene replacement was effective.


Asunto(s)
Terapia Genética/métodos , Corazón/fisiopatología , Distrofia Muscular de Cinturas/terapia , Proteínas/genética , Animales , Modelos Animales de Enfermedad , Técnicas de Inactivación de Genes , Humanos , Ratones , Distrofia Muscular de Cinturas/genética , Distrofia Muscular de Cinturas/fisiopatología , Distrofia Muscular Animal/terapia , Pentosiltransferasa
12.
Int J Mol Sci ; 15(3): 4393-414, 2014 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-24625664

RESUMEN

Glioblastoma multiforme (GBM) is the most malignant cancer in the central nervous system with poor clinical prognosis. In this study, we investigated the therapeutic effect of an anti-cancer protein, decorin, by delivering it into a xenograft U87MG glioma tumor in the brain of nude mice through an adeno-associated viral (AAV2) gene delivery system. Decorin expression from the AAV vector in vitro inhibited cultured U87MG cell growth by induction of cell differentiation. Intracranial injection of AAV-decorin vector to the glioma-bearing nude mice in vivo significantly suppressed brain tumor growth and prolonged survival when compared to control non-treated mice bearing the same U87MG tumors. Proteomics analysis on protein expression profiles in the U87MG glioma cells after AAV-mediated decorin gene transfer revealed up- and down-regulation of important proteins. Differentially expressed proteins between control and AAV-decorin-transduced cells were identified through MALDI-TOF MS and database mining. We found that a number of important proteins that are involved in apoptosis, transcription, chemotherapy resistance, mitosis, and fatty acid metabolism have been altered as a result of decorin overexpression. These findings offer valuable insight into the mechanisms of the anti-glioblastoma effects of decorin. In addition, AAV-mediated decorin gene delivery warrants further investigation as a potential therapeutic approach for brain tumors.


Asunto(s)
Neoplasias Encefálicas/terapia , Diferenciación Celular/fisiología , Decorina/fisiología , Terapia Genética/métodos , Glioblastoma/terapia , Animales , Western Blotting , Encéfalo/metabolismo , Encéfalo/patología , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Diferenciación Celular/genética , Línea Celular Tumoral , Decorina/genética , Decorina/metabolismo , Dependovirus/genética , Electroforesis en Gel Bidimensional , Vectores Genéticos/administración & dosificación , Vectores Genéticos/genética , Glioblastoma/genética , Glioblastoma/patología , Humanos , Ratones Desnudos , Proteoma/metabolismo , Proteómica/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Análisis de Supervivencia , Transducción Genética , Carga Tumoral/genética , Ensayos Antitumor por Modelo de Xenoinjerto
13.
Mol Ther ; 21(10): 1832-40, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23817215

RESUMEN

Mutations in the FKRP gene are associated with a wide range of muscular dystrophies from mild limb-girdle muscular dystrophy (LGMD) 2I to severe Walker-Warburg syndrome and muscle-eye-brain disease. The characteristic biochemical feature of these diseases is the hypoglycosylation of α-dystroglycan (α-DG). Currently there is no effective treatment available. In this study, we examined the adeno-associated virus serotype 9 vector (AAV9)-mediated gene therapy in the FKRP mutant mouse model with a proline to leucine missense mutation (P448L). Our results showed that intraperitoneal administration of AAV9-FKRP resulted in systemic FKRP expression in all striated muscles examined with the highest levels in cardiac muscle. Consistent with our previous observations, FKRP protein is localized in the Golgi apparatus in myofibers. Expression of FKRP consequently restored functional glycosylation of α-DG in the skeletal and cardiac muscles. Significant improvement in dystrophic pathology, serum creatine kinase levels and muscle function was observed. Only limited FKRP transgene expression was detected in kidney and liver with no detectable toxicity. Our results provided evidence for the utility of AAV-mediated gene replacement therapy for FKRP-related muscular dystrophies.


Asunto(s)
Dependovirus/genética , Distroglicanos/metabolismo , Terapia Genética/métodos , Músculo Esquelético/fisiología , Distrofia Muscular de Cinturas/terapia , Distrofia Muscular Animal/terapia , Proteínas/genética , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Vectores Genéticos , Glicosilación , Inyecciones Intraperitoneales , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Distrofia Muscular de Cinturas/metabolismo , Distrofia Muscular de Cinturas/fisiopatología , Pentosiltransferasa , Proteínas/metabolismo , Transferasas , Transgenes
14.
Biol Chem ; 394(4): 561-75, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23241588

RESUMEN

To look for oral proteasome inhibitors, daily injested food is the best source for cancer chemoprevention. A combination of active components from vegetables, coffee, tea, and fruit could be more efficient to inhibit 26S proteasome activities for preventing cancer diseases. Tannic acid and quercetin have been shown to strongly inhibit 26S proteasome activity, but the molecular target involved remains unknown. Overlay assay, peptide assay, Western blot, and 2-D gels were used to assess the combination of quercetin and tannic acid as a potential inhibitor. Here, we demonstrated that the combination of quercetin and tannic acid (1) synergistically suppresses chymotrypsin-, caspase-, and trypsin-like proteolytic activities, (2) are tightly binding substrates, (3) do not perturb the proteasome structure, (4) inhibit the 26S proteasome affected by ubiquitin, ATP, or ß-casein, and (5) inhibit ß-casein degradation by the 26S proteasome in vitro. Finally, the inhibition of the proteasome by a combination of quercetin plus tannic acid in Hep-2 cells resulted in the induction of S5a at low dose, accumulation of ubiquitin, and the cleavage of pro-caspase-3, followed by the induction of apoptotic cell death. Evaluating the combination of quercetin and tannic acid as an oral drug to prevent cancer may provide a pharmacological rationale to pursue preclinical trials of this combination.


Asunto(s)
Complejo de la Endopetidasa Proteasomal/efectos de los fármacos , Quercetina/farmacología , Taninos/farmacología , Ubiquitina/metabolismo , Animales , Apoptosis/efectos de los fármacos , Humanos , Leupeptinas/farmacología , Estructura Molecular
15.
Am J Pathol ; 178(1): 261-72, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21224063

RESUMEN

Limb-girdle muscular dystrophy 2I (LGMD2I) is caused by mutations in the fukutin-related protein (FKRP) gene. Unlike its severe allelic forms, LGMD2I usually involves slower onset and milder course without defects in the central nervous system. The lack of viable animal models that closely recapitulate LGMD2I clinical phenotypes led us to use RNA interference technology to knock down FKRP expression via postnatal gene delivery so as to circumvent embryonic lethality. Specifically, an adeno-associated viral vector was used to deliver short hairpin (shRNA) genes to healthy ICR mice. Adeno-associated viral vectors expressing a single shRNA or two different shRNAs were injected one time into the hind limb muscles. We showed that FKRP expression at 10 months postinjection was reduced by about 50% with a single shRNA and by 75% with the dual shRNA cassette. Dual-cassette injection also reduced a-dystroglycan glycosylation and its affinity to laminin by up to 70% and induced α-dystrophic pathology, including fibrosis and central nucleation, in more than 50% of the myofibers at 10 months after injection. These results suggest that the reduction of approximately or more than 75% of the normal level of FKRP expression induces chronic dystrophic phenotypes in skeletal muscles. Furthermore, the restoration of about 25% of the normal FKRP level could be sufficient for LGMD2I therapy to correct the genetic deficiency effectively and prevent dystrophic pathology.


Asunto(s)
Técnicas de Silenciamiento del Gen/métodos , Músculo Esquelético/patología , Distrofia Muscular de Cinturas/genética , Proteínas/genética , Interferencia de ARN , Adenoviridae , Animales , Línea Celular Tumoral , Modelos Animales de Enfermedad , Distroglicanos/metabolismo , Vectores Genéticos , Glicosilación , Ratones , Ratones Endogámicos ICR , Músculo Esquelético/metabolismo , Distrofia Muscular de Cinturas/metabolismo , Distrofia Muscular de Cinturas/patología , Pentosiltransferasa , ARN Interferente Pequeño/genética , Transferasas
16.
Hum Gene Ther ; 21(1): 87-97, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19719401

RESUMEN

The peripheral nervous system (PNS), including peripheral nerves and dorsal root ganglion (DRG), is involved in numerous neurological disorders, such as peripheral neuropathies (diabetic neuropathy, chronic pain, etc.) and demyelination diseases (multiple sclerosis, congenital muscular dystrophy, Charcot-Marie-Tooth disease, etc.). Effective clinical interventions for those diseases are very limited. Gene therapy represents a novel therapeutic strategy for the PNS diseases, especially with simply and minimally invasive delivery methods. Previously, we have shown that adeno-associated virus type 8 (AAV8) can efficiently transduce muscles body wide by a simple intraperitoneal injection in neonatal mice. In this study, we investigated the capacity of AAV8 in transducing PNS in neonatal mice by intraperitoneal injection and also in adult mice by intramuscular injection. Efficient and long-term gene transfer was found in the white matter of the spinal cord, DRG neurons, and peripheral nerves in both groups, treated either as neonates or as adults, particularly neonates. In the adult mice injected with AAV8 in tibialis anterior and gastrocnemius muscles in one of the hind legs, more neurons were transduced in the lower part of the spinal cord than in the upper part; the DRG neurons were transduced more on the vector-injected side than in the contralateral uninjected side. Few cells in the gray matter of the spinal cord were transduced regardless of the delivery methods and age of the mice. These results support the mechanism of vector retrograde transport and suggest that AAV8 crosses blood-nerve barrier poorly. Our finding should have important implications in gene therapy for peripheral neurological disorders.


Asunto(s)
Dependovirus/metabolismo , Ganglios Espinales/virología , Vectores Genéticos/administración & dosificación , Vectores Genéticos/metabolismo , Músculos/virología , Médula Espinal/virología , Animales , Animales Recién Nacidos , Transporte Biológico , Dependovirus/clasificación , Técnica del Anticuerpo Fluorescente , Ganglios Espinales/citología , Inyecciones Intramusculares , Ratones , Neuronas/citología , Neuronas/virología , Serotipificación , Médula Espinal/citología , Transducción Genética , beta-Galactosidasa/metabolismo
17.
Am J Chin Med ; 36(6): 1061-70, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19051336

RESUMEN

In order to provide a faster and easier way for outcome prediction of sepsis, this study aimed to characterize the pattern of arterial pulse spectrum by a rat cecum ligation and puncture (CLP) model and explore whether specific harmonic components of pulse spectrum are associated with the mortality of CLP rats, followed by the comparison of accuracy between these specific variables and IL-6. Nineteen Sprague-Dawley rats receiving CLP were analyzed. Femoral artery of each rat was catheterized for blood pressure recording and blood sampling in the first 24 hours after CLP. The former was for off-line pulse spectrum analysis, and the latter for IL-6 assay. These rats were observed for 3-day mortality after CLP, and were divided into survivor or non-survivor groups. Differences of the hemodynamic profile, IL-6, and changes of the harmonics between the 2 groups were analyzed by using the Mann-Whitney test. Kaplan-Meier curves were constructed to characterize cumulative survival with the best prognostic cutoff point. The characteristic changes of pulse spectrum were different between survivors and non-survivors. The percentage differences of the 2nd harmonic proportion (C2) increased significantly from the 10th hour after CLP, and was higher in the non-survivors. Serum levels of IL-6 were also higher in the non-survivor group. Analyzed by Kaplan-Meier survival curve for 3-day mortality, C2 had a higher accuracy than IL-6 as a predictor. The pulse spectrum analysis may be applied to evaluate the prognosis of CLP rats, and the rapidly and highly elevated C2 harmonic had a strong association with the 3-day mortality of CLP rats.


Asunto(s)
Medicina Tradicional China , Pulso Arterial , Sepsis/diagnóstico , Sepsis/fisiopatología , Animales , Presión Sanguínea , Modelos Animales de Enfermedad , Frecuencia Cardíaca , Humanos , Interleucina-6/sangre , Masculino , Valor Predictivo de las Pruebas , Ratas , Ratas Sprague-Dawley , Sepsis/mortalidad
18.
J Surg Res ; 132(1): 46-51, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16297404

RESUMEN

BACKGROUND: The inflammatory response plays an important role in the pathogenesis of sepsis, and the prognosis is known to be affected by the pro-inflammatory and anti-inflammatory cytokines. Therefore, a simple and reliable outcome prediction function that derived from IL-6 and IL-10 was hypothesized. MATERIAL AND METHODS: We used 27 Sprague-Dawley rats, weighing 250 to 300 g, underwent cecal ligation and puncture (CLP) procedures and femoral arterial catheterization. When the heart rates reached 1.15, 1.25, and 1.35 times that of the baseline heart rate, blood sampling was done for IL-6 and IL-10. The prognosis was followed up for 3 days after CLP, and all rats were then divided into survival or non-survival groups. Finally, the relationships among survival condition, heart rate, IL-6, and IL-10 were analyzed by two-way ANOVA and multiple comparison. A linear discriminant function for the prognosis of sepsis was developed by IL-6 and IL-10 at different heart rates. RESULTS: IL-6 elevated continuously with the increment of the heart rate in the non-survival group, but in the survival group, the IL-6 elevation started to fall when the heart rate reached 1.25 times; a similar trend was found in the change of IL-10. The prediction rate was 68.33% when the heart rate reached 1.15 times, and increased to 93.33% and 95.45% when heart rates reached 1.25 and 1.35 times, respectively. CONCLUSION: This linear discriminant function developed on the basis of IL-6 and IL-10 might be adopted as a simple and reliable indicator and further become a critical tool for the outcome prediction of sepsis.


Asunto(s)
Frecuencia Cardíaca/fisiología , Interleucina-10/sangre , Interleucina-6/sangre , Sepsis/inmunología , Sepsis/terapia , Abdomen , Animales , Biomarcadores/sangre , Ciego , Análisis Discriminante , Modelos Animales de Enfermedad , Frecuencia Cardíaca/inmunología , Masculino , Valor Predictivo de las Pruebas , Ratas , Ratas Sprague-Dawley , Sepsis/sangre , Sobrevida
19.
J Autoimmun ; 21(3): 247-54, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14599849

RESUMEN

Various therapeutic strategies have been developed to tolerize autoreactive T cells and prevent autoimmune pathology in type 1 diabetes. 4-1BB, a member of the tumor necrosis factor receptor (TNFR) superfamily, is a costimulatory receptor primarily expressed on activated T cells. The administration of an agonistic anti-4-1BB antibody (2A) dramatically reduced the incidence and severity of experimental autoimmune encephalomyelitis (EAE). Treatment with the same antibody in Fas-deficient MRL/lpr mice blocked lymphadenopathy and lupus-like autoimmune processes. Paradoxically, transgenic non-obese diabetic (NOD) mice overexpressing membrane-bound agonistic single-chain anti-4-1BB Fv in pancreatic beta cells developed more severe diabetes than their non-transgenic littermates, with earlier onset, faster diabetic processes, and higher mortality. Forty percent of transgenic mice developed diabetes by 4 weeks of age, compared with their control littermates, which first exhibited diabetes at 14 weeks. The frequency of diabetes in female transgenics reached 70% by 8 weeks of age. Most female transgenic mice died around 12 weeks. Consistent with this, transgenic mice developed earlier and more severe insulitis and showed stronger GAD-specific T-cell responses, compared with age-matched control littermates. Our results indicate an adverse effect of transgenic anti-4-1BB scFv in NOD mice and suggest a potential risk of this anti-4-1BB-based immunotherapy for autoimmune diseases.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Inmunoterapia/efectos adversos , Receptores de Factor de Crecimiento Nervioso/inmunología , Receptores del Factor de Necrosis Tumoral/inmunología , Animales , Antígenos CD , Células 3T3 BALB , Glucemia/análisis , Southern Blotting , Diabetes Mellitus Tipo 1/etiología , Diabetes Mellitus Tipo 1/patología , Modelos Animales de Enfermedad , Femenino , Expresión Génica , Tamización de Portadores Genéticos , Vectores Genéticos/genética , Glutamato Descarboxilasa/inmunología , Glucosuria/orina , Humanos , Fragmentos de Inmunoglobulinas/genética , Fragmentos de Inmunoglobulinas/farmacología , Región Variable de Inmunoglobulina/genética , Insulina/genética , Isoenzimas/inmunología , Activación de Linfocitos/inmunología , Masculino , Ratones , Ratones Endogámicos NOD , Ratones Transgénicos , Páncreas/patología , Fragmentos de Péptidos/inmunología , Fragmentos de Péptidos/farmacología , Regiones Promotoras Genéticas/genética , Receptores de Superficie Celular/genética , Receptores de Factor de Crecimiento Nervioso/agonistas , Receptores del Factor de Necrosis Tumoral/agonistas , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/farmacología , Factores Sexuales , Bazo/citología , Transfección , Miembro 9 de la Superfamilia de Receptores de Factores de Necrosis Tumoral
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA