Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Opt Express ; 31(13): 21419-21433, 2023 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-37381242

RESUMEN

Laser damage performance of DKDP (KD2xH2(1-x)PO4) crystal is largely determined by the surface microstructures generated in the manufacturing process, more specifically, single point diamond fly-cutting process. However, because of the lack of knowledge about the formation mechanism and damage performance of the microstructures, laser induced damage of DKDP crystal remains a key issue limiting the output energy of the high power laser systems. In this paper, the influence of fly-cutting parameters on the generation of DKDP surface and the underlying material deformation mechanism have been investigated. Except for cracks, two kinds of new microstructures, namely micro grains and ripples, have been found on the processed DKDP surfaces. GIXRD, nano-indentation and nano-scratch test results prove that the micro grains are generated by the slip motion of the crystal, while the simulation results show that the cracks are induced by the tensile stress formed behind the cutting edge. Moreover, the formation of micro grains can facilitate the plastic chip flow through the mechanism of grain boundary sliding, which will further lead to a periodic fluctuation of the chip separation point and the formation of micro ripples. Finally, laser damage test results demonstrate that cracks will degrade the damage performance of DKDP surface significantly, while the formation of micro grains and micro ripples has little impact. The results of this study can deepen the understanding of the formation mechanism of the DKDP surface during the cutting process and provide guidance to improve the laser-induced damage performance of the crystal.

2.
Clin Oral Investig ; 27(12): 7437-7450, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37848582

RESUMEN

OBJECTIVES: This study aimed to investigate the site-specific characteristics of rat mandible periosteal cells (MPCs) and tibia periosteal cells (TPCs) to assess the potential application of periosteal cells (PCs) in bone tissue engineering (BTE). MATERIALS AND METHODS: MPCs and TPCs were isolated and characterized. The potential of proliferation, migration, osteogenesis and adipogenesis of MPCs and TPCs were evaluated by CCK-8, scratch assay, Transwell assay, alkaline phosphatase staining and activity, Alizarin Red S staining, RT‒qPCR, and Western blot (WB) assays, respectively. Then, these cells were cocultured with human umbilical vein endothelial cells (HUVECs) to investigate their angiogenic capacity, which was assessed by scratch assay, Transwell assay, Matrigel tube formation assay, RT‒qPCR, and WB assays. RESULTS: MPCs exhibited higher osteogenic potential, higher alkaline phosphatase activity, and more mineralized nodule formation, while TPCs showed a greater capability for proliferation, migration, and adipogenesis. MPCs showed higher expression of angiogenic factors, and the conditioned medium of MPCs accelerated the migration of HUVECs, while MPC- conditioned medium induced the formation of more tubular structure in HUVECs in vitro. These data suggest that compared to TPCs, MPCs exert more consequential proangiogenic effects on HUVECs. CONCLUSIONS: PCs possess skeletal site-specific differences in biological characteristics. MPCs exhibit more eminent osteogenic and angiogenic potentials, which highlights the potential application of MPCs for BTE. CLINICAL RELEVANCE: Autologous bone grafting as the main modality for maxillofacial bone defect repair has many limitations. Constituting an important cell type in bone repair and regeneration, MPCs show greater potential for application in BTE, which provides a promising treatment option for maxillofacial bone defect repair.


Asunto(s)
Fosfatasa Alcalina , Osteogénesis , Humanos , Ratas , Animales , Medios de Cultivo Condicionados/farmacología , Medios de Cultivo Condicionados/metabolismo , Fosfatasa Alcalina/metabolismo , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Huesos , Células Cultivadas , Diferenciación Celular
3.
Bioorg Med Chem Lett ; 76: 128989, 2022 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-36150638

RESUMEN

Using small molecules to induce readthrough of premature termination codons is a promising therapeutic approach to treating genetic diseases and cancers caused by nonsense mutations, as evidenced by the widespread use of ataluren to treat nonsense mutation Duchene muscular dystrophy. Herein we describe a series of novel guanidino quinazoline and pyrimidine scaffolds that induce readthrough in both HDQ-P1 mammary carcinoma cells and mdx myotubes. Linkage of basic, tertiary amines with aliphatic, hydrophobic substituents to the terminal guanidine nitrogen of these scaffolds led to significant potency increases. Further potency gains were achieved by flanking the pyrimidine ring with hydrophobic substituents, inducing readthrough at concentrations as low as 120 nM and demonstrating the potential of these compounds to be used either in combination with ataluren or as stand-alone therapeutics.


Asunto(s)
Codón sin Sentido , Quinazolinas , Quinazolinas/farmacología , Pirimidinas/farmacología , Guanidinas , Nitrógeno , Aminas
4.
RNA ; 23(4): 567-577, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28096517

RESUMEN

Nonsense mutations resulting in a premature stop codon in an open reading frame occur in critical tumor suppressor genes in a large number of the most common forms of cancers and are known to cause or contribute to the progression of disease. Low molecular weight compounds that induce readthrough of nonsense mutations offer a new means of treating patients with genetic disorders or cancers resulting from nonsense mutations. We have identified the nucleoside analog clitocine as a potent and efficacious suppressor of nonsense mutations. We determined that incorporation of clitocine into RNA during transcription is a prerequisite for its readthrough activity; the presence of clitocine in the third position of a premature stop codon directly induces readthrough. We demonstrate that clitocine can induce the production of p53 protein in cells harboring p53 nonsense-mutated alleles. In these cells, clitocine restored production of full-length and functional p53 as evidenced by induced transcriptional activation of downstream p53 target genes, progression of cells into apoptosis, and impeded growth of nonsense-containing human ovarian cancer tumors in xenograft tumor models. Thus, clitocine induces readthrough of nonsense mutations by a previously undescribed mechanism and represents a novel therapeutic modality to treat cancers and genetic diseases caused by nonsense mutations.


Asunto(s)
Antimetabolitos Antineoplásicos/farmacología , Materiales Biomiméticos/farmacología , Codón sin Sentido/efectos de los fármacos , Furanos/farmacología , Nucleósidos/farmacología , Neoplasias Ováricas/tratamiento farmacológico , Nucleósidos de Pirimidina/farmacología , Proteína p53 Supresora de Tumor/agonistas , Animales , Antimetabolitos Antineoplásicos/síntesis química , Antimetabolitos Antineoplásicos/metabolismo , Apoptosis/efectos de los fármacos , Materiales Biomiméticos/síntesis química , Materiales Biomiméticos/metabolismo , Línea Celular Tumoral , Femenino , Furanos/síntesis química , Furanos/metabolismo , Genes Reporteros , Humanos , Luciferasas/genética , Luciferasas/metabolismo , Ratones , Ratones Desnudos , Nucleósidos/síntesis química , Nucleósidos/metabolismo , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/patología , Biosíntesis de Proteínas , Nucleósidos de Pirimidina/síntesis química , Nucleósidos de Pirimidina/metabolismo , Transducción de Señal , Activación Transcripcional , Carga Tumoral/efectos de los fármacos , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto
5.
Proc Natl Acad Sci U S A ; 113(44): 12508-12513, 2016 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-27702906

RESUMEN

A premature termination codon (PTC) in the ORF of an mRNA generally leads to production of a truncated polypeptide, accelerated degradation of the mRNA, and depression of overall mRNA expression. Accordingly, nonsense mutations cause some of the most severe forms of inherited disorders. The small-molecule drug ataluren promotes therapeutic nonsense suppression and has been thought to mediate the insertion of near-cognate tRNAs at PTCs. However, direct evidence for this activity has been lacking. Here, we expressed multiple nonsense mutation reporters in human cells and yeast and identified the amino acids inserted when a PTC occupies the ribosomal A site in control, ataluren-treated, and aminoglycoside-treated cells. We find that ataluren's likely target is the ribosome and that it produces full-length protein by promoting insertion of near-cognate tRNAs at the site of the nonsense codon without apparent effects on transcription, mRNA processing, mRNA stability, or protein stability. The resulting readthrough proteins retain function and contain amino acid replacements similar to those derived from endogenous readthrough, namely Gln, Lys, or Tyr at UAA or UAG PTCs and Trp, Arg, or Cys at UGA PTCs. These insertion biases arise primarily from mRNA:tRNA mispairing at codon positions 1 and 3 and reflect, in part, the preferred use of certain nonstandard base pairs, e.g., U-G. Ataluren's retention of similar specificity of near-cognate tRNA insertion as occurs endogenously has important implications for its general use in therapeutic nonsense suppression.


Asunto(s)
Codón sin Sentido/genética , Oxadiazoles/farmacología , ARN de Transferencia/genética , Ribosomas/efectos de los fármacos , Células HEK293 , Humanos , Biosíntesis de Proteínas/efectos de los fármacos , Estabilidad del ARN/efectos de los fármacos , ARN de Transferencia/metabolismo , Ribosomas/genética , Ribosomas/metabolismo , Transcripción Genética/efectos de los fármacos
6.
Immun Inflamm Dis ; 12(6): e1310, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38888464

RESUMEN

BACKGROUND: The PI3K/Akt/mTOR pathway and autophagy are important physiological processes. But their roles in eCRSwNP remains controversial. METHODS: In this study, we used the eCRSwNP mouse model, PI3K/Akt/mTOR pathway inhibitors, and autophagy inhibitors and activators to investigate the regulatory effects of the PI3K/Akt/mTOR pathway on autophagy, and their effects on eosinophilic inflammation, and tissue remodeling. The role of ILC2s in eCRSwNP was also studied, and the relationship between ILC2s and autophagy was preliminarily determined. RESULTS: Our results show that eosinophilic inflammation in eCRSwNP mice could be inhibited by promoting the autophagy; otherwise, eosinophilic inflammation could be promoted. Meanwhile, inhibition of the PI3K/Akt/mTOR pathway can further promote autophagy and inhibit eosinophilic inflammation. Meanwhile, inhibiting the PI3K/Akt/mTOR pathway and promoting autophagy can reduce the number of ILC2s and the severity of tissue remodeling in the nasal polyps of eCRSwNP mice. CONCLUSIONS: We conclude that the PI3K/Akt/mTOR pathway plays roles in eosinophilic inflammation and tissue remodeling of eCRSwNP, in part by regulating the level of autophagy. The downregulation of autophagy is a pathogenesis of eCRSwNP; therefore, the recovery of normal autophagy levels might be a new target for eCRSwNP therapy. Furthermore, autophagy might inhibit eosinophilic inflammation and tissue remodeling, in part by reducing the number of ILC2s.


Asunto(s)
Autofagia , Inmunidad Innata , Linfocitos , Pólipos Nasales , Fosfatidilinositol 3-Quinasas , Proteínas Proto-Oncogénicas c-akt , Transducción de Señal , Sinusitis , Serina-Treonina Quinasas TOR , Animales , Serina-Treonina Quinasas TOR/metabolismo , Ratones , Sinusitis/inmunología , Sinusitis/patología , Sinusitis/metabolismo , Autofagia/inmunología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Linfocitos/inmunología , Linfocitos/metabolismo , Enfermedad Crónica , Pólipos Nasales/inmunología , Pólipos Nasales/patología , Modelos Animales de Enfermedad , Eosinofilia/inmunología , Eosinofilia/patología , Eosinófilos/inmunología , Eosinófilos/patología , Eosinófilos/metabolismo , Ratones Endogámicos BALB C
7.
World Allergy Organ J ; 17(2): 100852, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38298830

RESUMEN

Background: Roles of ILC2s in allergic rhinitis (AR) and local allergic rhinitis (LAR) are unclear. In this study, we are determined to find the levels of autophagy and mitophagy of ILC2s in allergic nasal inflammation. Methods: ELISA was used to detect type 2 inflammatory cytokines. Hematoxylin and eosin (H&E) staining were used to compare the eosinophil (EOS) infiltration of nasal tissue specimens. Flow cytometry was used to detect the levels of ILC2s and Th2 cells. Immunohistochemistry (IHC) and Western blot (WB) were used to detect the levels of Beclin1, LC3, p62, PINK1, Parkin, FUNDC1, and BNIP3 in nasal mucosa. The levels of autophagy related proteins and mitophagy related proteins of the ILC2s were detected by WB. The number of autophagosomes of ILC2s was observed by transmission electron microscopy. The co-localization levels of GFP-LC3 and Mito tracker in ILC2s were observed by confocal microscopy using immunofluorescence. Results: We found that the level of type 2 inflammation in AR and LAR mice was significantly increased. The levels of autophagy and mitophagy of AR and LAR mice in nasal mucosa and ILC2s were both increased. Conclusions: ILC2s may be associated with the occurrence and development of nasal allergic inflammation. The abnormal increase of autophagy and mitophagy levels in the nose may be associated with the incidence of AR and LAR. Abnormal autophagy and mitophagy levels of ILC2s cells may be one of the causes of allergic nasal inflammation.

8.
World J Clin Cases ; 12(15): 2627-2635, 2024 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-38817239

RESUMEN

BACKGROUND: Multiple endocrine neoplasia type 2 (MEN2) is a rare, autosomal dominant endocrine disease. Currently, the RET proto-oncogene is the only gene implicated in MEN2A pathogenesis. Once an RET carrier is detected, family members should be screened to enable early detection of medullary thyroid carcinoma, pheochromocytoma, and hyperparatitity. Among these, medullary thyroid carcinoma is the main factor responsible for patient mortality. Accordingly, delineating strategies to inform clinical follow-up and treatment plans based on genes is paramount for clinical practitioners. CASE SUMMARY: Herein, we present RET proto-oncogene mutations, clinical characteristics, and treatment strategies in a family with MEN2A. A family study was conducted on patients diagnosed with MEN2A. DNA was extracted from the peripheral blood of family members, and first-generation exon sequencing of the RET proto-oncogene was conducted. The C634Y mutation was identified in three family members spanning three generations. Two patients were sequentially diagnosed with pheochromocytomas and bilateral medullary thyroid carcinomas. A 9-year-old child harboring the gene mutation was diagnosed with medullary thyroid carcinoma. Surgical resection of the tumors was performed. All family members were advised to undergo complete genetic testing related to the C634Y mutation, and the corresponding treatments administered based on test results and associated clinical guidelines. CONCLUSION: Advancements in MEN2A research are important for familial management, assessment of medullary thyroid cancer invasive risk, and deciding surgical timing.

9.
Nature ; 447(7140): 87-91, 2007 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-17450125

RESUMEN

Nonsense mutations promote premature translational termination and cause anywhere from 5-70% of the individual cases of most inherited diseases. Studies on nonsense-mediated cystic fibrosis have indicated that boosting specific protein synthesis from <1% to as little as 5% of normal levels may greatly reduce the severity or eliminate the principal manifestations of disease. To address the need for a drug capable of suppressing premature termination, we identified PTC124-a new chemical entity that selectively induces ribosomal readthrough of premature but not normal termination codons. PTC124 activity, optimized using nonsense-containing reporters, promoted dystrophin production in primary muscle cells from humans and mdx mice expressing dystrophin nonsense alleles, and rescued striated muscle function in mdx mice within 2-8 weeks of drug exposure. PTC124 was well tolerated in animals at plasma exposures substantially in excess of those required for nonsense suppression. The selectivity of PTC124 for premature termination codons, its well characterized activity profile, oral bioavailability and pharmacological properties indicate that this drug may have broad clinical potential for the treatment of a large group of genetic disorders with limited or no therapeutic options.


Asunto(s)
Codón sin Sentido/genética , Enfermedades Genéticas Congénitas/tratamiento farmacológico , Enfermedades Genéticas Congénitas/genética , Oxadiazoles/farmacología , Oxadiazoles/uso terapéutico , Biosíntesis de Proteínas/efectos de los fármacos , Alelos , Animales , Disponibilidad Biológica , Distrofina/biosíntesis , Distrofina/genética , Enfermedades Genéticas Congénitas/sangre , Humanos , Ratones , Ratones Endogámicos mdx , Oxadiazoles/administración & dosificación , Oxadiazoles/farmacocinética , Fenotipo , Biosíntesis de Proteínas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Especificidad por Sustrato
10.
Front Bioeng Biotechnol ; 11: 1209652, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37744250

RESUMEN

The effects of the menstrual cycle and sex hormones on knee kinematics remain unclear. The purpose of the study was to investigate the effects of the menstrual cycle and serum sex hormone concentrations on knee kinematic parameters of the 90°cutting in female college soccer athletes. Three female college soccer teams (53 subjects) participated in the study. During the first menstrual cycle, a three-step method was used to exclude subjects with anovulatory and luteal phase-deficient (LPD) (12 subjects). The subjects' menstrual cycle was divided into the menstrual phase, late-follicular phase, ovulatory phase, and mid-luteal phase (group 1, 2, 3, 4). In each phase of the second menstrual cycle, we used a portable motion analysis system to enter the teams and tested the sex hormones concentrations and knee kinematics parameters in three universities in turn. We found that subjects had a lower maximum knee valgus in group 4 compared with other groups. This meant that subjects had a lower biomechanical risk of non-contact anterior cruciate ligament (ACL) injury in the mid-luteal phase. There was no significant correlation between serum estrogen, progesterone concentration, and knee kinematic parameters. This meant that sex hormones did not have a protective effect. Future studies need to incorporate more factors (such as neuromuscular control, etc.) to investigate.

11.
Zhongguo Zhen Jiu ; 43(3): 282-6, 2023 Mar 12.
Artículo en Zh | MEDLINE | ID: mdl-36858389

RESUMEN

OBJECTIVE: To evaluate the effect of transcutaneous acupoint electrical stimulation (TEAS) at Neiguan (PC 6) on general anesthesia under preserving spontaneous breathing in thoracoscopic lobectomy. METHODS: A total of 66 patients of primary lung cancer undergoing thoracoscopic lobectomy were divided to an observation group (33 cases, 1 case discontinued) and a control group (33 cases). In the observation group, TEAS at Neiguan (PC 6) was used 30 min before anesthesia induction till the end of surgery. The surgery time, maximum value of partial pressure of end-tidal carbon dioxide (PETCO2) and minimum value of oxygen saturation (SpO2) of the two groups were recorded. The dosage of propofol, sufentanil, remifentanil and dexmedetomidine were analyzed. Separately, before induction (T0), at the start of surgery (T1), thoracic exploration (T2) and lobectomy (T3), as well as 30 min (T4) and 60 min (T5) after lobectomy, the mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), serum cortisol (Cor) and norepinephrine (NE) were measured. The time of post anesthesia care unit (PACU) stay, ambulation, flatus, chest drainage and the incidence of nausea and vomiting were compared between the two groups. RESULTS: The maximum value of PETCO2, the dosage of propofol and remifentanil in the observation group were lower than those in the control group (P < 0.05, P < 0.01), the minimum value of SpO2 in the observation group was higher than that of the control group (P < 0.01). At T1-T5, the MAP, HR, serum Cor and NE levels in the observation group were all lower than those in the control group (P < 0.05). The ambulation time, the time for the flatus, chest drainage time, and the incidence of nausea and vomiting in the observation group were all lower than those in the control group (P<0.001, P < 0.01). CONCLUSION: For the general anesthesia under preserving spontaneous breathing in thoracoscopic surgery, TEAS at Neiguan (PC 6) relieves stress response, reduces opioids dosage and promotes postoperative recovery.


Asunto(s)
Puntos de Acupuntura , Propofol , Humanos , Dióxido de Carbono , Flatulencia , Remifentanilo , Anestesia General , Náusea , Norepinefrina , Estimulación Eléctrica
12.
Neurochem Int ; 168: 105566, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37339717

RESUMEN

The 5-hydroxytryptamine 7 receptor (5-HT7R) is one of the most recently cloned serotonin receptors which have been implicated in many physiological and pathological processes including drug addiction. Behavioral sensitization is the progressive process during which re-exposure to drugs intensified the behavioral and neurochemical responses to drugs. Our previous study has demonstrated that the ventrolateral orbital cortex (VLO) is critical for morphine-induced reinforcing effect. The aim of the present study was to investigate the effect of 5-HT7Rs in the VLO on morphine-induced behavioral sensitization and their underlying molecular mechanisms. Our results showed that a single injection of morphine, followed by a low challenge dose could induce behavioral sensitization. Microinjection of the selective 5-HT7R agonist AS-19 into the VLO during the development phase significantly increased morphine-induced hyperactivity. Microinjection of the 5-HT7R antagonist SB-269970 suppressed acute morphine-induced hyperactivity and the induction of behavioral sensitization, but had no effect on the expression of behavioral sensitization. In addition, the phosphorylation of AKT (Ser 473) was increased during the expression phase of morphine-induced behavioral sensitization. Suppression of the induction phase could also block the increase of p-AKT (Ser 473). In conclusion, we demonstrated that 5-HT7Rs and p-AKT in the VLO at least partially contribute to morphine-induced behavioral sensitization.


Asunto(s)
Morfina , Serotonina , Ratas , Animales , Serotonina/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas Sprague-Dawley , Corteza Prefrontal/metabolismo
13.
Front Psychol ; 13: 1033439, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36507022

RESUMEN

The influence mechanism for brand experience in virtual sports brand communities is the subject of many studies, but these studies do not feature a holistic consideration of antecedents and consequences, and the moderating role of brand attachment is unclear. Drawing on the value co-creation theory, this study determines the impact of brand experience and its mechanism using the data from 508 virtual sports brand communities. The empirical test results show that value co-creation (i.e., corporate-initiated value co-creation and customer-initiated value co-creation) has a positive effect on the brand experience and that the brand experience has a positive effect on the purchase intention. Brand attachment does not have a moderating role between brand experience and purchase intention so as the degree of brand attachment increases, the brand experience does not increase the purchase intention through a brand attachment. This study determines the antecedents and consequences of brand experience in virtual sports brand communities from a value co-creation perspective, to determine the impact and mechanisms of virtual sports brand communities to guide the marketing practices of virtual sports brand communities.

14.
Macromol Biosci ; 22(2): e2100265, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34705332

RESUMEN

Massive oral and maxillofacial bone defect regeneration remains a major clinical challenge due to the absence of functionalized bone grafts with ideal mechanical and proregeneration properties. In the present study, Laponite (LAP), a synthetic nanosilicate, is incorporated into polycaprolactone (PCL) to develop a biomaterial for bone regeneration. It is explored whether LAP-embedded PCL would accelerate bone regeneration by orchestrating osteoblasts to directly and indirectly induce bone regeneration processes. The results confirmed the presence of LAP in PCL, and LAP is distributed in the exfoliated structure without aggregates. Incorporation of LAP in PCL slightly improved the compressive properties. LAP-embedded PCL is biocompatible and exerts pronounced enhancements in cell viability, osteogenic differentiation, and extracellular matrix formation of osteoblasts. Furthermore, osteoblasts cultured on LAP-embedded PCL facilitate angiogenesis of vessel endothelial cells and alleviate osteoclastogenesis of osteoclasts in a paracrine manner. The addition of LAP to the PCL endows favorable bone formation in vivo. Based upon these results, LAP-embedded PCL shows great potential as an ideal bone graft that exerts both space-maintaining and vascularized bone regeneration synergistic effects and can be envisioned for oral and maxillofacial bone defect regeneration.


Asunto(s)
Células Endoteliales , Osteogénesis , Materiales Biocompatibles/química , Regeneración Ósea , Diferenciación Celular , Osteoblastos , Poliésteres/química , Andamios del Tejido/química
15.
Eur J Med Chem ; 244: 114826, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36242990

RESUMEN

Dihydroorotate dehydrogenase (DHODH) is the enzyme that catalyzes a rate-determining step during the de novo synthesis of uridine, an important source of cellular pyrimidine nucleotides. Ability to modulate the activity of this enzyme may be used to control diseases associated with rapid, out-of-control cell growth in oncology, immunology, and virology. Emvododstat (PTC299) is a tetrahydro-ß-carboline DHODH inhibitor discovered through the GEMS technology (Gene Expression Modulation by Small-Molecules). Described in this paper is the lead optimization campaign that culminated in the discovery of this highly potent DHODH inhibitor.


Asunto(s)
Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Dihidroorotato Deshidrogenasa , Inhibidores Enzimáticos/farmacología , Carbamatos
16.
World J Clin Cases ; 10(33): 12319-12327, 2022 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-36483813

RESUMEN

BACKGROUND: Acute intermittent porphyria (AIP) is a rare autosomal dominant porphyrin metabolic disease caused by a mutation in the hydroxymethylbilane synthase (HMBS) gene. This study aimed to explore the clinical manifestations of a patient with AIP, to identify a novel HMBS gene mutation in the proband and some of her family members, and to confirm the pathogenicity of the variant. CASE SUMMARY: A 22-year-old Chinese woman developed severe abdominal pain, lumbago, sinus tachycardia, epileptic seizure, hypertension, and weakness in lower limbs in March, 2018. Biochemical examinations indicated hypohepatia and hyponatremia. Her last menstrual period was 45 d prior to admission, and she was unaware of the pregnancy, which was confirmed by a pregnancy test after admission. Sunlight exposure of her urine sample for 1 h turned it from yellow to wine red. Urinary porphyrin test result was positive. Based on these clinical manifestations, AIP was diagnosed. After increasing her daily glucose intake (250-300 g/d), abdominal pain was partially relieved. Three days after hospitalization, spontaneous vaginal bleeding occurred, which was confirmed as spontaneous abortion; thereafter, her clinical symptoms completely resolved. Genetic testing revealed a novel heterozygous splicing variant of the HMBS gene in exon 10 (c.648_651+1delCCAGG) in the proband and four other family members. The pathogenicity of the variant was verified through bioinformatic methods and a minigene assay. CONCLUSION: We identified a novel HMBS gene mutation in a Chinese patient with AIP and confirmed its pathogenicity.

17.
Regen Biomater ; 8(1): rbaa045, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33732491

RESUMEN

Guided bone regeneration in inflammatory microenvironments of osteoporotic patients with large alveolar bone defects remains a great challenge. Macrophages are necessary for alveolar bone regeneration via their polarization and paracrine actions. Our previous studies showed that Cu-bearing Ti6Al4V alloys are capable of regulating macrophage responses. When considering the complexity of oral microenvironments, the influences of Cu-bearing Ti6Al4V alloys on osteoporotic macrophages in infectious microenvironments are worthy of further investigations. In this study, we fabricated Ti6Al4V-Cu alloy by selective laser melting technology and used Porphyromonas gingivalis lipopolysaccharide (P.g-LPS) to imitate oral pathogenic bacterial infections. Then, we evaluated the impacts of Ti6Al4V-Cu on osteoporotic macrophages in infectious microenvironments. Our results indicated that Ti6Al4V-Cu not only inhibited the P.g-LPS-induced M1 polarization and pro-inflammatory cytokine production of osteoporotic macrophages but also shifted polarization towards the pro-regenerative M2 phenotype and remarkably promoted anti-inflammatory cytokine release. In addition, Ti6Al4V-Cu effectively promoted the activity of COMMD1 to potentially repress NF-κB-mediated transcription. It is concluded that the Cu-bearing Ti6Al4V alloy results in ameliorated osteoporotic macrophage responses to create a favourable microenvironment under infectious conditions, which holds promise to develop a GBR-barrier membrane for alveolar bone regeneration of osteoporosis patients.

18.
Zhongguo Zhen Jiu ; 41(6): 598-602, 2021 Jun 12.
Artículo en Zh | MEDLINE | ID: mdl-34085474

RESUMEN

OBJECTIVE: To observe the protective effect of electroacupuncture (EA) at Neiguan (PC 6) on pulmonary function during one-lung ventilation (OLV) in patients with lobectomy, and explore its action mechanism. METHODS: Sixty patients with lobectomy were randomly divided into an observation group and a control group, 30 cases in each one. The patients in the control group were treated with general anesthesia, and OLV was given when surgery began; when the surgery finished, air was removed from the thoracic cavity and two-lung ventilation was performed. On the basis of the treatment in the control group, the patients in the observation group were treated with EA (disperse-dense wave, 2 Hz/100 Hz of frequency) at Neiguan (PC 6) 30 min before anesthesia induction until the end of the surgery. The pulmonary function indexes [arterial partial pressure of oxygen (PaO2), oxygenation index (OI), compliance of lung (CL), respiratory index (RI)] and serum levels of superoxide dismutase (SOD), malondialdehyde (MDA), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were observed before surgery (T0), 30 min into OLV (T1), 60 min into OLV (T2) and after operation (T3). The total incidence of complications, pressing times of postoperative patient-controlled analgesia pump in 48 h after surgery and hospital stay were compared between the two groups. RESULTS: Compared with T0, the PaO2, OI, CL and serum SOD at T1, T2 and T3 in the two groups were decreased (P<0.05), and those in the observation group were higher than those in the control group (P<0.05). The RI and serum levels of MDA, IL-6, TNF-α at T1, T2 and T3 in the two groups were increased, and those in the observation group were lower than those in the control group (P<0.05). The total incidence of complications in the observation group was lower than that in the control group [3.3% (1/30) vs 23.3% (7/30), P<0.05]. The pressing times of postoperative patient-controlled analgesia pump in 48 h after surgery and hospital stay in the observation group were less than those in the control group (P<0.05). CONCLUSION: EA at Neiguan (PC 6) has protective effects on lung injury induced by OLV after lobectomy, and its mechanism may be related to the improvement of oxidative stress and inflammatory response.


Asunto(s)
Electroacupuntura , Lesión Pulmonar , Ventilación Unipulmonar , Anestesia General , Humanos , Pulmón
19.
Regen Biomater ; 8(6): rbab061, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34858634

RESUMEN

Critical oral-maxillofacial bone defects, damaged by trauma and tumors, not only affect the physiological functions and mental health of patients but are also highly challenging to reconstruct. Personalized biomaterials customized by 3D printing technology have the potential to match oral-maxillofacial bone repair and regeneration requirements. Laponite (LAP) nanosilicates have been added to biomaterials to achieve biofunctional modification owing to their excellent biocompatibility and bioactivity. Herein, porous nanosilicate-functionalized polycaprolactone (PCL/LAP) was fabricated by 3D printing technology, and its bioactivities in bone regeneration were investigated in vitro and in vivo. In vitro experiments demonstrated that PCL/LAP exhibited good cytocompatibility and enhanced the viability of bone marrow mesenchymal stem cells (BMSCs). PCL/LAP functioned to stimulate osteogenic differentiation of BMSCs at the mRNA and protein levels and elevated angiogenic gene expression and cytokine secretion. Moreover, BMSCs cultured on PCL/LAP promoted the angiogenesis potential of endothelial cells by angiogenic cytokine secretion. Then, PCL/LAP scaffolds were implanted into the calvarial defect model. Toxicological safety of PCL/LAP was confirmed, and significant enhancement of vascularized bone formation was observed. Taken together, 3D-printed PCL/LAP scaffolds with brilliant osteogenesis to enhance bone regeneration could be envisaged as an outstanding bone substitute for a promising change in oral-maxillofacial bone defect reconstruction.

20.
J Nanosci Nanotechnol ; 9(2): 1263-7, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19441502

RESUMEN

In this study, nanostructured transition metal oxides, such as Co3O4, NiO and MnO2 were comprehensively studied and reported as promising electrode materials for electrochemical capacitors. The materials have been obtained by solution or spray solution techniques, which are cost-effective and promising for industry application. All materials feature a large specific surface area, which can reach up to 270 m2/g. The high surface area is a compulsory condition for high capacitance. The best MnO2 materials yielded up to 406 F/g.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA