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1.
Front Pediatr ; 12: 1390856, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38803636

RESUMO

Background: Intestinal malrotation is a rare condition, and its delayed diagnosis can lead to fatal consequences. This study aimed to investigate the identification and treatment of malrotation in children. Methods: Clinical data, imaging, operative findings, and early postoperative outcomes of 75 children with malrotation were retrospectively analyzed. Results: The mean age was 6.18 ± 4.93 days and 51.26 ± 70.13 months in the neonatal group (56 patients) and non-neonatal group (19 patients), respectively. Sixty-seven patients were under the age of 1 year at the time of diagnosis. The occurrence of bilious vomiting and jaundice was significantly higher in the neonatal group (89.29%) than that in the non-neonatal group (37.5%), p < 0.05 and p < 0.01, respectively. The incidence of abnormal ultrasound (US) findings was 97.30% and 100%, respectively, and the sensitivities of the upper gastrointestinal series were 84.21% and 87.5%, respectively. Sixty-six (88%) patients had midgut volvulus, including in utero volvulus (two patients) and irreversible intestinal ischemia (four patients). Most neonates (89.29%) underwent open Ladd's procedure with a shorter operative time (p < 0.01). Reoperation was performed for postoperative complications (four patients) or missed comorbidities (two patients). Conclusions: Non-bilious vomiting was the initial symptom in >10% of neonates and nearly 40% of non-neonates. This highlights the importance for emergency physicians and surgeons to be cautious about ruling out malrotation in patients with non-bilious vomiting. Utilizing US can obviate the need for contrast examinations owing to its higher diagnostic accuracy and rapid diagnosis and can be recommended as a first-line imaging technique. Additionally, open surgery is still an option for neonatal patients.

2.
Biomed Rep ; 20(4): 68, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38533389

RESUMO

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous family of myeloid cells that suppress T cell immunity in tumor-bearing hosts. The present study aimed to examine roles of T and MDSC subsets in lung malignancy. The study analyzed 102 cases with lung malignancy and 34 healthy individuals. Flow cytometry was performed for identification of T cell and MDSC subsets and their phenotypic characteristics in peripheral blood. The lung malignancy cases exhibited lower frequencies of granulocyte-like MDSCs (G-MDSCs) expressing PD-L2 and PD-L1 than healthy controls (P=0.013 and P<0.001, respectively). Additionally, there was a higher frequency of monocyte-like MDSCs (M-MDSCs) expressing PD-L1 in the peripheral blood of patients with lung malignancy than healthy controls (P<0.001). The frequencies of G-MDSCs and M-MDSCs were positively correlated with proportions of PD-1+ and CTLA-4+ regulatory T cells (Tregs). In vitro co-culture assay demonstrated M-MDSCs of lung malignancy enhanced naive T cell apoptosis and promoted Treg subset differentiation compared with M-MDSCs of healthy controls. The findings suggested accumulation of MDSC subsets in lung malignancy and MDSCs expressing PD-L2 and PD-L1 induced Treg expansion by binding to PD-1 on the surface of Tregs.

3.
Front Genet ; 14: 1289346, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38155713

RESUMO

The prevalence of Anaplastic Lymphoma Kinase gene (ALK) fusion is about 5% among patients with lung adenocarcinoma, underscoring the importance of pinpointing distinct fusion variants for optimizing treatment approaches. This is the first reported case of a 74-year-old female with stage IV lung adenocarcinoma, featuring a novel Kinesin Family Member 13A (KIF13A)-ALK fusion, identified via next-generation sequencing (NGS) and confirmed with fluorescence in situ hybridization (FISH). Initially undergoing chemotherapy and then crizotinib, she achieved a partial response (PR) before progressing with multiple bone metastases. However, subsequent treatment with alectinib as a third-line option yielded positive results. A stable disease state persisted for an impressive 31 months of progression-free survival (PFS), accompanied by minimal toxicity symptoms. Up until now, a remarkable near 4-year span of overall survival (OS) has been consistently observed and monitored. This report of a KIF13A-ALK fusion case benefit significantly from alectinib with extensive follow-up. The case diversifies the array of ALK fusion partners and holds clinical relevance in refining therapeutic choices for KIF13A-ALK fusion-associated lung cancer.

4.
PLoS One ; 18(9): e0291455, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37756307

RESUMO

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) have been reported to expand and have a potent ability in the expansion of regulatory T cells in malignant and infectious disease. The current study was performed to investigate the role of MDSCs and possible immune mechanisms in dampening immune responses of community acquired pneumonia (CAP). METHODS: This was a single-center cross-sectional study. The distribution of MDSCs subsets, the PD-1/PD-L1(L2) level of MDSCs subsets and Tregs in the peripheral blood of adult CAP patients and healthy control were measured by flow cytometry analysis. RESULTS: Peripheral blood mononuclear cells (PBMCs) from 63 adult CAP patients contained an elevated frequency of both G-MDSC (4.92±0.30 vs 2.25±0.21,p<0.0001) and M-MDSC (19.40±1.30 vs 9.64±0.57,p<0.001) compared to healthy controls. Treg in the peripheral blood of CAP patients exhibited increased expression of PD-1 and CTLA-4, accompanied by no difference of their frequency. Moreover, up-regulated expression of PD-L1 on MDSC subsets in the peripheral blood of CAP patients was also revealed. Of note, the frequency of circulating MDSCs subset displayed a positive correlation with neutrophil count percentage in blood in CAP patients. CONCLUSIONS: In summary, the significant expansion of circulating MDSCs subsets and the up-regulated expression of PD-1/PD-L1 level in CAP patients may suggest the possible involvement of PD-1/PD-L1axis in MDSCs mediated immune regulation on Treg at least partially in CAP patients.


Assuntos
Infecções Comunitárias Adquiridas , Células Supressoras Mieloides , Pneumonia , Humanos , Adulto , Regulação para Cima , Antígeno B7-H1 , Estudos Transversais , Leucócitos Mononucleares , Receptor de Morte Celular Programada 1
5.
Biomed Rep ; 19(2): 55, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37560314

RESUMO

The roles of myeloid-derived suppressor cells (MDSCs) and regulatory T-cells (Tregs) in acute myocardial infarction (AMI) remain elusive. The present study aimed to analyze the proportions of the granulocytic and monocytic populations of MDSCs (G-MDSCs and M-MDSCs, respectively), and Tregs in the peripheral blood mononuclear cells (PBMCs) of patients with AMI. The present study recruited 34 patients with AMI and 37 healthy controls without clinical signs of myocardial ischemia. PBMCs were isolated from the peripheral blood samples of patients with AMI within 24 h following admission to the hospital and from those of the healthy controls during a physical examination. Two subsets of MDSCs, G-MDSCs (CD15+CD33+CD11b+CD14-HLA-DRlow) and M-MDSCs (CD14+CD15-CD11b+HLA-DRlow), and Tregs (CD3+CD4+CD25highCD127low T-cells) in the PBMCs derived from the patients with AMI and healthy controls were analyzed using flow cytometry. The effects of MDSCs derived from patients with AMI on naïve CD4+ T-cells were examined in the co-culture system. The results revealed that the proportions of G-MDSCs and M-MDSCs were higher in the peripheral blood of patients with AMI than in that of the healthy controls. The patients with AMI had significantly higher numbers of programmed death-ligand (PD-L)1- and PD-L2-positive G-MDSCs and M-MDSCs compared with the healthy controls (P<0.05). The MDSCs could acquire a granulocytic phenotype following AMI, and the G-MDSCs and M-MDSCs would be more likely to express PD-L2 and PD-L1, respectively. The ratios of Tregs to CD4+ T-cells and PD-1+ Tregs in the peripheral blood of patients with AMI were significantly higher than those in the healthy controls (P<0.05). The results of flow cytometry demonstrated an increase in the numbers of inducible Tregs in the co-culture system with the G-MDSCs derived from patients with AMI compared with the G-MDSCs derived from the healthy controls (P<0.01). On the whole, the findings presented herein demonstrate the accumulation of MDSCs, and the upregulation of PD-L1 and PD-L2 expression on the surface of MDSCs in patients with AMI. MDSCs can induce the expansion of Tregs by binding PD-1 on the surface of Tregs, thus playing a crucial role in AMI.

6.
Exp Ther Med ; 20(3): 2099-2105, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32782522

RESUMO

The aim of the present study was to evaluate the effectiveness of interventional treatment of primary tracheal tumors through flexible bronchoscopy. The clinical data of 38 patients with primary tracheal tumours who underwent flexible bronchoscopy intervention therapy between January 2011 and January 2017 were retrospectively analyzed. The average time interval from onset of symptoms to the appearance of actual clinical manifestations in the 38 patients ranged from 0 to 60 months, with an average of 8.1±11.6 months and a median of 4.2 months. The rate of misdiagnosis at the first visit was 36.8% (14/38). After interventional treatment, the overall efficiency (complete + partial response) of airway stenosis recanalization in the 38 patients was 89.5%. In 3 patients with benign tumors, the anhelation score was reduced following treatment (1.00±0.77 vs. 3.13±1.21 at the pre-treatment stage; P<0.001). The overall survival rates of the 35 patients at 1, 3 and 5 years were 69.3, 48.7 and 20.3%, respectively. Therefore, flexible bronchoscopic intervention may effectively smoothen the airways of patients and relieve the symptoms of anhelation. Combining radiotherapy and chemotherapy may improve patient prognosis and safety.

7.
Technol Health Care ; 28(S1): 207-216, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32364153

RESUMO

BACKGROUND: The aircraft cockpit is a highly intensive human-computer interaction system, and its design directly affects flight safety. OBJECTIVE: To optimize the display interface design in complex flight tasks, the present study aimed to propose a dynamic conceptual framework and a timeline task analysis method for the quantization of the dynamic time effect of mental workload and the influencing factors of task types in the mental workload prediction model. METHODS: The multi-factor mental workload prediction model based on attention resource allocation was integrated to establish the dynamic prediction model of mental workload. The ergonomics simulation experiment was carried out by recording the data on the performance of embedded subtasks, National Aeronautics and Space Administration-Task Load Index (NASA-TLX) subjective evaluation, and eye tracking. RESULTS: The results indicated that the prediction model had a good prediction accuracy and effectiveness under different simulated interfaces and complex tasks, and the real-time monitoring of pilots' mental workload state was realized. CONCLUSION: In conclusion, the prediction model and the experimental method could be applied to avoid the overload of the pilot throughout the flight phase by optimizing the display interface and adjusting the flight task.


Assuntos
Fadiga Mental/fisiopatologia , Pilotos , Adulto , Atenção , Ergonomia , Movimentos Oculares , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Análise e Desempenho de Tarefas , Fatores de Tempo , Carga de Trabalho/psicologia , Adulto Jovem
9.
J Biomed Nanotechnol ; 15(12): 2305-2320, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31748013

RESUMO

Verteporfin photodynamic therapy (PDT) has been approved for the treatment of exudative age-related macular degeneration (AMD) for over a decade. However, its extensive application has been impeded by inevitably collateral tissue damage and immediate induction of angiogenesis, in addition to the need of multiple treatments. In order to develop prospective photosensitizers for clinical use, a triphenyl phosphonium-modified cationic liposomal hypocrellin B (TPP cationic LHB) for angiogenic targeting and endothelial internalization was constructed. With optimal PDT parameters, TPP cationic LHB can lead to death of choroid-retinal vascular endothelial cells while cause negligible damage to collateral retinal pigment epithelium cells. This is likely due to the mitochondria targeting and effective intracellular singlet oxygen generation of TPP cationic LHB in vascular endothelial cells. Additionally, in vivo chick chorioallantoic membrane assay indicated the elevated neovessel-targeting ability and photo-induced anti-angiogenic activity of TPP cationic LHB. Furthermore, TPP cationic LHB PDT is able to maintain neovessel occlusion for an extended period of time compared with verteporfin PDT, without inducing significant increased expression of some angiogenic factors, such as vascular endothelial growth factor and integrin αvß3. This study describes a facile strategy that may be useful for developing new-generation photosensitizers to circumvent the limitations of PDT treatment of exudative AMD.


Assuntos
Degeneração Macular , Perileno/análogos & derivados , Fotoquimioterapia , Quinonas/uso terapêutico , Animais , Neovascularização de Coroide , Células Endoteliais , Lipossomos , Degeneração Macular/tratamento farmacológico , Perileno/uso terapêutico , Fármacos Fotossensibilizantes , Estudos Prospectivos , Fator A de Crescimento do Endotélio Vascular
10.
RSC Adv ; 9(19): 10927-10936, 2019 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-35515302

RESUMO

Lung cancer is the most frequent cause of cancer deaths in the world, and smoking is considered as one of the major causes. Small cell lung carcinoma (SCLC) represents a highly malignant and particularly aggressive form, with properties of widespread metastases and poor prognosis. Herein, twenty-five Scolopendra subspinipes mutilans L. Koch Oligopeptides (SSMOs) were isolated and their structures were identified, and the anti-proliferative activity against lung cancer cell lines was evaluated. Results showed that SSMO-5 induced the production of reactive oxygen species (ROS) markedly in NCI-H446 cells. Furthermore, SSMO-5 decreased the mitochondrial membrane potential (MMP) and enhanced the mitochondria-related apoptosis. These results demonstrate that in NCI-H446 cells, the apoptotic and cytotoxic effects of SSMO-5 are mediated by the intrinsic mitochondria-mediated apoptotic pathway, which in turn causes the activation of caspases and increases Bax expression, while decreases Bcl-2 and Bcl-xL expressions and regulates the interaction of p53/MDM2. In conclusion, a ROS-mediated mitochondrial pathway plays an important role in the process of SSMO-5-induced apoptosis against SCLC.

11.
Entropy (Basel) ; 21(6)2019 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-33267333

RESUMO

The performance of a 300 kW organic Rankine cycle (ORC) prototype was experimentally investigated for low-grade waste heat recovery in industry. The prototype employed a specially developed single-stage radial turbine that was integrated with a semi-hermetic three-phase asynchronous generator. R245fa was selected as the working fluid and hot water was adopted to imitate the low-grade waste heat source. Under approximately constant cooling source operating conditions, variations of the ORC performance with diverse operating parameters of the heat source (including temperature and volume flow rate) were evaluated. Results revealed that the gross generating efficiency and electric power output could be improved by using a higher heat source temperature and volume flow rate. In the present experimental research, the maximum electric power output of 301 kW was achieved when the heat source temperature was 121 °C. The corresponding turbine isentropic efficiency and gross generating efficiency were up to 88.6% and 9.4%, respectively. Furthermore, the gross generating efficiency accounted for 40% of the ideal Carnot efficiency. The maximum electric power output yielded the optimum gross generating efficiency.

12.
World J Gastroenterol ; 22(19): 4757-65, 2016 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-27217707

RESUMO

AIM: To explore Chinese physicians' perceptions towards fecal microbiota transplantation (FMT) and to provide information and an assessment of FMT development in China. METHODS: A self-administered questionnaire was developed according to the FMT practice guidelines and was distributed to physicians in hospitals via Internet Research Electronic Data Capture (REDcap) software and electronic mails to assess their attitudes toward and knowledge of FMT. The questionnaire included a brief introduction of FMT that was followed by 20 questions. The participants were required to respond voluntarily, under the condition of anonymity and without compensation. Except for the fill-in-the-blank questions, all of the other questions were required in the REDcap data collection systems, and the emailed questionnaires were completed based on eligibility. RESULTS: Up to December 9, 2014, 844 eligible questionnaires were received out of the 980 distributed questionnaires, with a response rate of 86.1%. Among the participants, 87.3% were from tertiary hospitals, and there were 647 (76.7%) gastroenterologists and 197 (23.3%) physicians in other departments (non-gastroenterologists). Gastroenterologists' awareness of FMT prior to the survey was much higher than non-gastroenterologists' (54.3 vs 16.5%, P < 0.001); however, acceptance of FMT was not statistically different (92.4 vs 87.1%, P = 0.1603). Major concerns of FMT included the following: acceptability to patients (79.2%), absence of guidelines (56.9%), and administration and ethics (46.5%). On the basis of understanding, the FMT indications preferred by physicians were recurrent Clostridium difficile infection (86.7%), inflammatory bowel disease combined with Clostridium difficile infection (78.6%), refractory ulcerative colitis (70.9%), ulcerative colitis (65.4%), Crohn's disease (59.4%), chronic constipation (43.7%), irritable bowel syndrome (39.1%), obesity (28.1%) and type 2 diabetes (23.9%). For donor selection, the majority of physicians preferred individuals with a similar gut flora environment to the recipients. 76.6% of physicians chose lower gastrointestinal tract as the administration approach. 69.2% of physicians considered FMT a safe treatment. CONCLUSION: Chinese physicians have awareness and a high acceptance of FMT, especially gastroenterologists, which provides the grounds and conditions for the development of this novel treatment in China. Physicians' greatest concerns were patient acceptability and absence of guidelines.


Assuntos
Atitude do Pessoal de Saúde , Transplante de Microbiota Fecal , Gastroenteropatias/terapia , Conhecimentos, Atitudes e Prática em Saúde , Percepção , Médicos/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Conscientização , China , Feminino , Gastroenteropatias/diagnóstico , Gastroenteropatias/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Especialização , Inquéritos e Questionários , Adulto Jovem
13.
Science ; 348(6235): 690-3, 2015 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-25954008

RESUMO

Photosynthetic splitting of water into oxygen by plants, algae, and cyanobacteria is catalyzed by the oxygen-evolving center (OEC). Synthetic mimics of the OEC, which is composed of an asymmetric manganese-calcium-oxygen cluster bound to protein groups, may promote insight into the structural and chemical determinants of biological water oxidation and lead to development of superior catalysts for artificial photosynthesis. We synthesized a Mn4Ca-cluster similar to the native OEC in both the metal-oxygen core and the binding protein groups. Like the native OEC, the synthetic cluster can undergo four redox transitions and shows two magnetic resonance signals assignable to redox and structural isomerism. Comparison with previously synthesized Mn3CaO4-cubane clusters suggests that the fourth Mn ion determines redox potentials and magnetic properties of the native OEC.


Assuntos
Cálcio/química , Manganês/química , Mimetismo Molecular , Oxigênio/química , Fotossíntese , Complexo de Proteína do Fotossistema II/química , Água/química
14.
Photochem Photobiol Sci ; 14(5): 972-81, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25793654

RESUMO

Photodynamic therapy (PDT) has been successfully implemented as a treatment for wet age-related macular degeneration (AMD), but very few photosensitizers have been developed for clinical use. Herein, we describe a novel formulation of liposomal hypocrellin B (LHB) that was prepared by high-pressure homogenization. The encapsulation efficiency and PDT efficacy in vitro of this new preparation were found to remain nearly constant over 1 year. Moreover, LHB is rapidly cleared from the blood, with a half-life of 2.319 ± 0.462 h and a very low serum concentration at 24 h after injection. Testing in a rat model of choroidal neovascularization (CNV) showed that leakage of blood vessels in CNV lesions was significantly reduced when LHB PDT was given at a dose of 1 mg kg(-1) along with yellow laser irradiation; the damage to the collateral retina and the retinal pigment epithelium was minimal. Skin phototoxicity assays showed that only two of the 200 mice given a 4 mg per kg dose of LHB experienced an inflammatory reaction in the auricle irradiated at 24 h after dosing. These data collectively indicate that LHB may be a safe and effective photosensitizer for vascular-targeted PDT of AMD.


Assuntos
Perileno/análogos & derivados , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/administração & dosagem , Quinonas/administração & dosagem , Degeneração Macular Exsudativa/terapia , Animais , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Células Cultivadas , Neovascularização de Coroide , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Orelha/patologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/fisiologia , Células Endoteliais/efeitos da radiação , Feminino , Lipossomos/síntese química , Pulmão/irrigação sanguínea , Masculino , Camundongos , Microvasos/efeitos dos fármacos , Microvasos/fisiologia , Microvasos/efeitos da radiação , Tamanho do Órgão , Perileno/administração & dosagem , Perileno/síntese química , Perileno/farmacocinética , Perileno/toxicidade , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/farmacocinética , Fármacos Fotossensibilizantes/toxicidade , Quinonas/síntese química , Quinonas/farmacocinética , Quinonas/toxicidade , Ratos , Retina/efeitos dos fármacos , Retina/patologia , Retina/efeitos da radiação , Pele/efeitos dos fármacos , Pele/patologia , Pele/efeitos da radiação , Degeneração Macular Exsudativa/patologia
15.
Dalton Trans ; 44(10): 4431-5, 2015 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-25662151

RESUMO

A novel family of heteronuclear Mn(IV)Ca-oxido complexes containing Mn(IV)Ca-oxido cuboidal moieties and reactive water molecules on Ca(2+) have been synthesized and characterized to mimic the oxygen-evolving complex (OEC) of photosystem II (PSII) in nature.


Assuntos
Materiais Biomiméticos/química , Cálcio/química , Complexos de Coordenação/química , Manganês/química , Oxigênio/química , Complexo de Proteína do Fotossistema II/química , Materiais Biomiméticos/síntese química , Complexos de Coordenação/síntese química , Modelos Moleculares , Água/química
16.
J Photochem Photobiol B ; 142: 169-77, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25543550

RESUMO

State transition and non-photochemical fluorescence quenching in cyanobacteria are short-term adaptations of photosynthetic apparatus to changes in light quality and intensity, however, the kinetic details and relationship are still not clear. In this work, time-dependent 77K fluorescence spectra were monitored for cyanobacterium Synechocystis PCC 6803 cells under blue, orange and blue-green light in a series of intensities. The characteristic fluorescence signals indicated state transition taking place exclusively under 430-450 or 580-600nm light or 480-550nm light at the intensities ⩽150µEm(-2)s(-1) to achieve a conserved level with variable rate constant. Under 480-500nm or 530-550nm light at the intensities ⩾160µEm(-2)s(-1), state transition took place at first but stopped as soon as the fluorescence quenching appeared. The dependence of appearance, induction period, level and rate constant for the quenching on light intensity suggests that a critical concentration of photo-activated OCPs is necessary and may be achieved by a dynamic equilibrium between the activation and deactivation under light.


Assuntos
Luz , Synechocystis/efeitos da radiação , Transferência de Energia , Recuperação de Fluorescência Após Fotodegradação , Cinética , Complexo de Proteína do Fotossistema I/química , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema II/química , Complexo de Proteína do Fotossistema II/metabolismo , Ficocianina/química , Synechocystis/metabolismo
17.
J Photochem Photobiol B ; 138: 249-55, 2014 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-24995991

RESUMO

The high-affinity chloride ion (Cl(-)) is known to play a key role in water oxidation in photosystem II (PSII). Recent crystallographic studies revealed two Cl(-) binding sites in PSII. To examine whether these two Cl(-) ions are correlated to the high-affinity Cl(-), we prepared Cl(-)/Br(-)/I(-)-substituted PSII samples from both higher plants and cyanobacteria by using two different protocols: one was the method used in the crystallographic study (Type 1) and the other was a method developed recently to ensure the efficient replacement of Cl(-) (Type 2). While only minor effects were observed in the Type 1 preparation, efficient Br(-)/I(-)substitution by the Type 2 protocol led to significant changes in the EPR properties of the oxygen-evolving complex (OEC) and the TyrZ, as well as in oxygen-evolving activities. These results are discussed in terms of the binding site of the high-affinity Cl(-) relative to the two Cl(-) ions revealed by the recent X-ray structural data.


Assuntos
Brometos/química , Iodetos/química , Oxigênio/química , Complexo de Proteína do Fotossistema II/metabolismo , Cloretos/química , Cianobactérias/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Íons/química , Luz , Complexo de Proteína do Fotossistema II/química , Plantas/metabolismo , Estrutura Terciária de Proteína
18.
Chem Commun (Camb) ; 50(66): 9263-5, 2014 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-24816273

RESUMO

A novel heterometallic MnSr complex containing the Mn3SrO4 cuboidal moiety and all types of µ-O(2-) moieties observed in the oxygen-evolving complex (OEC) in Sr(2+)-containing photosystem II (PSII) has been synthesized and characterized, which provides a new synthetic model of the OEC.


Assuntos
Modelos Moleculares , Oxigênio/química , Complexo de Proteína do Fotossistema II/química , Estrôncio/química , Espectroscopia de Ressonância de Spin Eletrônica
19.
Photodiagnosis Photodyn Ther ; 11(2): 204-12, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24534694

RESUMO

BACKGROUND: Photodynamic therapy (PDT) is an approved therapeutic procedure that exerts cytotoxic activity toward tumor cells by irradiating photosensitizers with light exposure to produce reactive oxygen species (ROS). An ideal photosensitizer is a crucial element to PDT. In the current study, we evaluated the photodynamic activity of a novel photosensitizer, the derivative of hypocrellin B (HB), 17-(3-amino-1-pentanesulfonic acid)-substituted hypocrellin B Schiff-base (PENSHB), both in vitro and in vivo. METHODS: Physicochemical characteristics of the novel photosensitizer were compared with that of its parent HB. The intracellular distribution of photosensitizers and mitochondrial membrane potential were detected with laser scanning confocal microscopy. The pathway of cell death was analyzed by flow cytometry. The release of proapoptotic proteins was evaluated by Western blot. S180 tumor model was used to evaluate the antitumor effects of PENHB-mediated PDT. RESULTS: Compared with its parent HB, water solubility of the derivative was improved enormously (6.6 mg/ml vs. 4.6 µg/ml), rendering its intravenous injection feasible without auxiliary solvent. The derivative had better PDT effect than HB in vitro under similar dark cytotoxicity. Moreover, PENSHB-mediated PDT was able to induce mitochondrial inner membrane permeabilisation, cytochrome c release, caspase-3 activation and subsequent apoptotic death. In vivo study showed that more than half of tumor bearing mice were cured by PENSHB-mediated PDT. CONCLUSIONS: In vitro and in vivo studies suggest that PENSHB is an effective photosensitizer for PDT to tumors. Therefore, PENSHB as a novel photosensitizer has a good prospect of clinical application.


Assuntos
Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Perileno/análogos & derivados , Fotoquimioterapia/métodos , Quinonas/síntese química , Quinonas/uso terapêutico , Animais , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Humanos , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos C57BL , Perileno/síntese química , Perileno/uso terapêutico , Fármacos Fotossensibilizantes/uso terapêutico , Bases de Schiff/química , Resultado do Tratamento
20.
Asian Pac J Cancer Prev ; 13(7): 3465-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22994779

RESUMO

AIM: Platinum agents have shown to be effective in the treatment of colorectal cancer. We assessed whether single nucleotide polymorphisms (SNPs) in GSTP1, ERCC1 Asn118Asn and ERCC2 Lys751Gln might predict the overall survival in patients receiving oxaliplatin-based chemotherapy in a Chinese population. METHODS: SNPs of GSTP1, ERCC1 Asn118Asn and ERCC2 Lys751Gln in 335 colorectal cancer patients were assessed using TaqMan nuclease assays. RESULTS: At the time of final analysis on Nov. 2011, the median follow-up period was 37.7 months (range from 1 to 60 months). A total of 229 patients died during follow-up. Our study showed GSTP1 Val/Val (HR=0.44, 95% CI=0.18-0.98), ERCC1 C/C (HR=0.20, 95% CI=0.10-0.79) and ERCC2 G/G (HR=0.48, 95% CI=0.19-0.97) to be significantly associated with better survival of colorectal cancer. GSTP1 Val/Val, ERCC1 C/C and ERCC2 G/G were also related to longer survival among patients with colon cancer, with HRs (95% CIs) of 0.41 (0.16-0.91), 0.16 (0.09-0.74) and 0.34 (0.16-0.91), respectively. CONCLUSION: GSTP1, GSTP1, ERCC1 Asn118Asn and ERCC2 Lys751Gln genotyping might facilitate tailored oxaliplatin-based chemotherapy for colorectal cancer patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Proteínas de Ligação a DNA/genética , Endonucleases/genética , Glutationa S-Transferase pi/genética , Proteína Grupo D do Xeroderma Pigmentoso/genética , Idoso , Povo Asiático/genética , Quimioterapia Adjuvante/métodos , Neoplasias Colorretais/metabolismo , Proteínas de Ligação a DNA/biossíntese , Endonucleases/biossíntese , Feminino , Seguimentos , Genótipo , Glutationa S-Transferase pi/biossíntese , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Organoplatínicos/administração & dosagem , Oxaliplatina , Polimorfismo de Nucleotídeo Único , Resultado do Tratamento , Proteína Grupo D do Xeroderma Pigmentoso/biossíntese
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