Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
1.
J Am Chem Soc ; 145(18): 10431-10440, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37099266

RESUMO

Great success in synthetic chemistry is motivated by the development of novel and reactive linchpins for carbon-carbon and carbon-heteroatom bond formation reactions, which has dramatically altered chemists' approach to building molecules. Herein, we report the ready synthesis of aryl sulfonium salts, a versatile electrophilic linchpin, via a novel Cu-mediated thianthrenation and phenoxathiination of commercially available arylborons with thianthrene and phenoxathiine, providing a series of aryl sulfonium salts in high efficiency. More importantly, by leveraging the sequential Ir-catalyzed C-H borylation and Cu-mediated thianthrenation of arylborons, the formal thianthrenation of arenes is also achieved. The Ir-catalyzed C-H borylation with undirected arenes normally occurred at the less steric hindrance position, thus providing a complementary method for thianthrenation of arenes in comparison with electrophilic thianthrenation. This process is capable of late-stage functionalization of a series of pharmaceuticals, which might find wide synthetic applications in both industry and academic sectors.

2.
Org Biomol Chem ; 15(4): 984-990, 2017 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-28067385

RESUMO

The first DBU-catalyzed Michael/Pinner/isomerization cascade reaction of 3-hydrooxindoles with isatylidene malononitriles was developed, and the corresponding highly functionalized bispirooxindoles containing a fully substituted dihydrofuran motif were obtained in up to 92% yields. This protocol also provides an efficient method for the synthesis of an α-cyano-γ-butyrolactone bispirooxindole. In addition, a one-pot three-component cascade reaction was conducted. Also, the asymmetric version of the cascade reaction was achieved.

3.
World J Gastrointest Oncol ; 16(3): 991-1005, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38577443

RESUMO

BACKGROUND: The precise role of mitochondrial carrier homolog 2 (MTCH2) in promoting malignancy in gastric mucosal cells and its involvement in gastric cancer cell metastasis have not been fully elucidated. AIM: To determine the role of MTCH2 in gastric cancer. METHODS: We collected 65 samples of poorly differentiated gastric cancer tissue and adjacent tissues, constructed MTCH2-overexpressing and MTCH2-knockdown cell models, and evaluated the proliferation, migration, and invasion of human gastric epithelial cells (GES-1) and human gastric cancer cells (AGS) cells. The mitochondrial membrane potential (MMP), mitochondrial permeability transformation pore (mPTP) and ATP fluorescence probe were used to detect mitochondrial function. Mitochondrial function and ATP synthase protein levels were detected via Western blotting. RESULTS: The expression of MTCH2 and ATP2A2 in gastric cancer tissues was significantly greater than that in adjacent tissues. Overexpression of MTCH2 promoted colony formation, invasion, migration, MMP expression and ATP production in GES-1 and AGS cells while upregulating ATP2A2 expression and inhibiting cell apoptosis; knockdown of MTCH2 had the opposite effect, promoting overactivation of the mPTP and promoting apoptosis. CONCLUSION: MTCH2 can increase the malignant phenotype of GES-1 cells and promote the proliferation, invasion, and migration of gastric cancer cells by regulating mitochondrial function, providing a basis for targeted therapy for gastric cancer cells.

4.
J Hematol ; 13(1-2): 12-22, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38644985

RESUMO

Background: Polycythemia vera (PV) is a myeloproliferative neoplasm. Ropeginterferon alfa-2b is a new-generation polyethylene glycol-conjugated proline-interferon. It is approved for the treatment of PV at a starting dose of 100 µg (50 µg for patients receiving hydroxyurea (HU)) and dose titrations up to 500 µg by 50 µg increments. The study was aimed at assessing its efficacy and safety at a higher starting dose and simpler intra-patient dose escalation. Methods: Forty-nine patients with PV having HU intolerance from major hospitals in China were treated biweekly with an initial dose of 250 µg, followed by 350 µg and 500 µg thereafter if tolerated. Complete hematological response (CHR) was assessed every 12 weeks based on the European LeukemiaNet criteria. The primary endpoint was the CHR rate at week 24. The secondary endpoints included CHR rates at weeks 12, 36 and 52, changes of JAK2V617F allelic burden, time to first CHR, and safety assessments. Results: The CHR rates were 61.2%, 69.4% and 71.4% at weeks 24, 36, and 52, respectively. Mean allele burden of the driver mutation JAK2V617F declined from 58.5% at baseline to 30.1% at 52 weeks. Both CHR and JAK2V617F allele burden reduction showed consistent increases over the 52 weeks of the treatment. Twenty-nine patients (63.0%) achieved partial molecular response (PMR) and two achieved complete molecular response (CMR). The time to CHR was rapid and median time was 5.6 months according to central lab results. The CHRs were durable and median CHR duration time was not reached at week 52. Mean spleen index reduced from 55.6 cm2 at baseline to 50.2 cm2 at week 52. Adverse events (AEs) were mostly mild or moderate. Most common AEs were reversible alanine aminotransferase and aspartate aminotransferase increases, which were not associated with significant elevations in bilirubin levels or jaundice. There were no grade 4 or 5 AEs. Grade 3 AEs were reversible and manageable. Only one AE led to discontinuation. No incidence of thromboembolic events was observed. Conclusion: The 250-350-500 µg dosing regimen was well tolerated and effectively induced CHR and MR and managed spleen size increase. Our findings demonstrate that ropeginterferon alfa-2b at this dosing regimen can provide an effective management of PV and support using this dosing regimen as a treatment option.

5.
Comp Immunol Microbiol Infect Dis ; 72: 101514, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32634650

RESUMO

Hepatozoon canis, transmitted by Rhipicephalus sanguineus, is a tick-borne pathogen and causes canine hepatozoonosis. Until now, only limited previous studies were conducted on the molecular detection and characterization of Hepatozoon sp. in dogs in China. Blood samples were collected from 93 sick dogs that were clinically diagnosed as babesiosis but tested negative for Babesia, and 103 apparently healthy dogs, as well as their infesting ticks in Xi'an and Hanzhong cities, Shaanxi province of China. PCR amplifying partial 18S rRNA gene was used to detect the DNA of Hepatozoon sp. Genetic and phylogenetic analysis were performed to determine the Hepatozoon species. Our results demonstrated that H. canis was identified from the sick dogs and the infested ticks in Hanzhong, with no significant differences of prevalence between both genders and ages. No positive blood or tick samples were found in Xi'an. Moreover, all the 18S rRNA gene sequences recovered from both dogs and the infested ticks showed a high genetic similarity with each other, and also presented a close relationship with other known sequences in and outside China. In conclusion, H. canis was identified in babesiosis-suspected dogs and ticks infesting them in Shaanxi, China, although the association between clinical signs and H. canis need further study.


Assuntos
Coccidiose/veterinária , Doenças do Cão , Eucoccidiida , Animais , China/epidemiologia , Coccidiose/epidemiologia , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Cães , Eucoccidiida/genética , Eucoccidiida/isolamento & purificação , Feminino , Masculino , Filogenia
6.
Infect Genet Evol ; 74: 103927, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31220612

RESUMO

Anaplasma bovis, causative agent of bovine anaplasmosis, is usually identified by nested-PCR amplifying the rrs gene. However, it is difficult to determine the genetic relationship among different variants within A. bovis using this gene because of high conservation. In this study, two tick species, identified as Rhipicephalus microplus and Haemaphysalis longicornis based on morphological and molecular methods by analyzing COI gene, were collected from cattle, goat or sheep. Subsequently, A. bovis was initially detected by PCR amplifying the rrs gene in ticks in Shaanxi Province, China. The sequencing and Blast results showed that some false positive samples were found when only based on the amplification of partial rrs gene, presenting these sequences resembled those of other Alphaproteobacteria rather than A. bovis. Although major surface proteins genes were proposed and used successfully to identify members within Anaplasmataceae, these genes were unavailable for A. bovis. Hence, primers targeting the groEL gene were designed and a PCR assay was developed. The PCR products were sequenced and similarity and phylogenetic analysis suggested all these sequences are the groEL gene of A. bovis. In addition, phylogenetic analysis based on the groEL gene also revealed the genetic diversity of A. bovis worldwide, as well as in Shaanxi Province of China, which wasn't reflected by analyzing the rrs gene. In sum, groEL gene is important for molecular detection and phylogenetic analysis of A. bovis.


Assuntos
Anaplasma/classificação , Proteínas de Choque Térmico/genética , Tipagem Molecular/normas , Carrapatos/microbiologia , Anaplasma/genética , Anaplasma/isolamento & purificação , Animais , Proteínas de Bactérias/genética , Bovinos/parasitologia , China , Variação Genética , Cabras/parasitologia , Filogenia , Reação em Cadeia da Polimerase/normas , Análise de Sequência de DNA/métodos , Ovinos/parasitologia , Carrapatos/classificação
7.
Oral Oncol ; 82: 1-7, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29909882

RESUMO

OBJECTIVE: This study aimed to (a) assess the differences in the delineation of target volumes and organs-at-risk (OARs) by different physicians designing an intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC) and (b) analyze the impact of these differences on the treatment plan optimization. MATERIALS AND METHODS: The planning target volumes (PTVs) and OARs for radiotherapy were manually delineated from computed tomography images of a patient with NPC, and a standard delineation was determined using the STAPLE algorithm of ABAS software. IMRT was designed using one standard plan and 10 individual plans based on the same constraints and field conditions. The maximum/minimum ratio (MMR) of the PTV and OAR volumes and the coefficient of variation (CV) for the different groups were evaluated and compared to the volume of the standard contour. RESULTS: Significant differences were seen in the PTVs of the nasopharynx (PTVnx), neck lymph node (PTVnd) and the OARs manually delineated by different physicians. Compared to the standard plan, the mean dose-related parameters of various OARs in different individual plans were not significantly different, while that of most organs in different individual plans were reduced. However, a significant difference in the dose at each organ was noted in different individual plans. CONCLUSION: Significant differences were noted in the PTV and OAR delineations by different physicians in radiotherapy of NPC, and their dosimetric parameters were significantly different from the standard planned parameters. Therefore, multicenter trials should pay attention to the impact of these differences on the clinical evaluation.


Assuntos
Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/radioterapia , Variações Dependentes do Observador , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/métodos , Idoso , Humanos , Masculino , Carcinoma Nasofaríngeo/diagnóstico por imagem , Neoplasias Nasofaríngeas/diagnóstico por imagem , Radioterapia de Intensidade Modulada/efeitos adversos , Tomografia Computadorizada por Raios X
8.
Huan Jing Ke Xue ; 29(7): 2012-7, 2008 Jul.
Artigo em Zh | MEDLINE | ID: mdl-18828393

RESUMO

Using the indoor simulating method of dynamic and static exposure respectively, the toxic effects of TBBPA on the antioxidant enzyme defense systems and Glutathione-S-transferase (GST) activity of tubifex Monopylephorus limosus were examined. The activity of superoxide dismutase (SOD) and catalase (CAT) with time was also examined. The results showed that after an 8 d exposure, the SOD activity was enhanced at first and then inhibited gradually, at last enhanced again. The highest activity of SOD (p < 0.01) was examined under 0.05 mg/L concentration of TBBPA. And the activity of SOD was much higher than that of control (1.5-7.8 times more than that of the control). The activity of CAT showed a tendency of induction firstly and then inhibition, then induction again and at last inhibition, reached the highest value under 0.5 mg/L of TBBPA. Furthermore, the CAT activity was higher than that of the control (1.1-1.9 times more than that of the control) except that under 0.005 mg/L and 0.25 mg/L of TBBPA. Moreover, the highest activity of GST (p < 0.01) was observed under 0.25 mg/L of TBBPA. The activity of GST was enhanced gradually at first and then inhibited. As the same as SOD, the activity of GST was induced significantly (p < 0.05). The changes in the SOD activity showed an "M" trend,while that in the CAT activity showed an "N" trend. And the activity of SOD is steadier than that of CAT. Thus, changes in the activity of SOD and GST, especially SOD, can better reflect the toxic effects of pollutants on tubifex.


Assuntos
Estresse Oxidativo/efeitos dos fármacos , Bifenil Polibromatos/toxicidade , Poliquetos/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Catalase/metabolismo , Glutationa Transferase/metabolismo , Poliquetos/enzimologia , Superóxido Dismutase/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA