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1.
Sci Rep ; 14(1): 14057, 2024 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890451

RESUMO

This study aimed to explore the mediating effects of ADL and depression on the relationship between sleep quality and HRQOL among older people in rural China, while also exploring the moderating impact of loneliness. The study gathered data from a household survey conducted among 1587 Chinese rural older adults (mean age = 73.63 years). The collected data was analyzed using SPSS version 23.0 software (IBM, New York, USA) and the PROCESS macro version 4.0 program. The findings indicated a significant correlation between sleep quality, ADL, depression, loneliness and HRQOL. ADL and depression exhibited a chain mediation effect on the relationship between sleep quality and HRQOL. Notably, the association between sleep quality and HRQOL was entirely mediated by ADL and depression. Additionally, loneliness acted as a moderator in the relationship between ADL and HRQOL. The findings of this study suggest that interventions focusing on sleep quality should prioritize strategies for enhancing older adults' ADL and depression as integral components of promoting older adults' HRQOL.


Assuntos
Atividades Cotidianas , Depressão , Qualidade de Vida , Qualidade do Sono , Humanos , Idoso , Depressão/psicologia , Masculino , Feminino , Idoso de 80 Anos ou mais , China/epidemiologia , Solidão/psicologia , Pessoa de Meia-Idade , População Rural , Inquéritos e Questionários
2.
Nucleic Acids Res ; 51(19): 10782-10794, 2023 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-37702119

RESUMO

Phosphorothioate (PT)-modification was discovered in prokaryotes and is involved in many biological functions such as restriction-modification systems. PT-modification can be recognized by the sulfur binding domains (SBDs) of PT-dependent restriction endonucleases, through coordination with the sulfur atom, accompanied by interactions with the DNA backbone and bases. The unique characteristics of PT recognition endow SBDs with the potential to be developed into gene-targeting tools, but previously reported SBDs display sequence-specificity for PT-DNA, which limits their applications. In this work, we identified a novel sequence-promiscuous SBDHga from Hahella ganghwensis. We solved the crystal structure of SBDHga complexed with PT-DNA substrate to 1.8 Å resolution and revealed the recognition mechanism. A shorter L4 loop of SBDHga interacts with the DNA backbone, in contrast with previously reported SBDs, which interact with DNA bases. Furthermore, we explored the feasibility of using SBDHga and a PT-oligonucleotide as targeting tools for site-directed adenosine-to-inosine (A-to-I) RNA editing. A GFP non-sense mutant RNA was repaired at about 60% by harnessing a chimeric SBD-hADAR2DD (deaminase domain of human adenosine deaminase acting on RNA), comparable with currently available RNA editing techniques. This work provides insights into understanding the mechanism of sequence-specificity for SBDs and for developing new tools for gene therapy.


Assuntos
Edição de RNA , Humanos , Adenosina Desaminase/metabolismo , DNA/química , Edição de Genes , RNA/metabolismo , Enxofre/química
3.
Chiropr Man Therap ; 31(1): 14, 2023 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-37226172

RESUMO

BACKGROUND: Spinal manipulative therapy (SMT) is a guideline-recommended treatment option for spinal pain. The recommendation is based on multiple systematic reviews. However, these reviews fail to consider that clinical effects may depend on SMT "application procedures" (i.e., how and where SMT is applied). Using network meta-analyses, we aim to investigate which SMT "application procedures" have the greatest magnitude of clinical effectiveness for reducing pain and disability, for any spinal complaint, at short-term and long-term follow-up. We will compare application procedural parameters by classifying the thrust application technique and the application site (patient positioning, assisted, vertebral target, region target, Technique name, forces, and vectors, application site selection approach and rationale) against: 1. Waiting list/no treatment; 2. Sham interventions not resembling SMT (e.g., detuned ultrasound); 3. Sham interventions resembling SMT; 4. Other therapies not recommended in clinical practice guidelines; and 5. Other therapies recommended in clinical practice guidelines. Secondly, we will examine how contextual elements, including procedural fidelity (whether the SMT was delivered as planned) and clinical applicability (whether the SMT is similar to clinical practice) of the SMT. METHODS: We will include randomized controlled trials (RCT) found through three search strategies, (i) exploratory, (ii) systematic, and (iii) other known sources. We define SMT as a high-velocity low-amplitude thrust or grade V mobilization. Eligibility is any RCT assessing SMT against any other type of SMT, any other active or sham intervention, or no treatment control on adult patients with pain in any spinal region. The RCTs must report on continuous pain intensity and/or disability outcomes. Two authors will independently review title and abstract screening, full-text screening, and data extraction. Spinal manipulative therapy techniques will be classified according to the technique application and choice of application sites. We will conduct a network-meta analysis using a frequentist approach and multiple subgroup and sensitivity analyses. DISCUSSION: This will be the most extensive review of thrust SMT to date, and will allow us to estimate the importance of different SMT application procedures used in clinical practice and taught across educational settings. Thus, the results are applicable to clinical practice, educational settings, and research studies. PROSPERO registration: CRD42022375836.


Assuntos
Osteopatia , Manipulação da Coluna , Adulto , Humanos , Metanálise em Rede , Coluna Vertebral , Dor , Metanálise como Assunto
4.
BMC Bioinformatics ; 23(1): 483, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376802

RESUMO

Microorganisms in the human body have a great impact on human health. Therefore, mastering the potential relationship between microorganisms and diseases is helpful to understand the pathogenesis of diseases and is of great significance to the prevention, diagnosis, and treatment of diseases. In order to predict the potential microbial disease relationship, we propose a new computational model. Firstly, a bi-directional heterogeneous microbial disease network is constructed by integrating multiple similarities, including Gaussian kernel similarity, microbial function similarity, disease semantic similarity, and disease symptom similarity. Secondly, the neighbor information of the network is learned by random walk; Finally, the selection model is used for information aggregation, and the microbial disease node pair is analyzed. Our method is superior to the existing methods in leave-one-out cross-validation and five-fold cross-validation. Moreover, in case studies of different diseases, our method was proven to be effective.


Assuntos
Algoritmos , Biologia Computacional , Humanos , Biologia Computacional/métodos , Semântica
5.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-990594

RESUMO

Objective:To investigate the clinical value of totally laparoscopic exclusion of splenic artery aneurysm combined with pericardial devascularization for portal hypertension com-plicated with splenic aneurysm.Methods:The retrospective and descriptive study was conducted. The clinicopathological data of 17 patients with portal hypertension complicated with splenic aneurysm who were admitted to 2 medical centers (15 cases in Shenzhen University General Hospital and 2 cases in Wuhan First Hospital) from January 2013 to May 2020 were collected. There were 7 males and 10 females, aged (59±14)years. All patients underwent totally laparoscopic exoclusion of splenic artery aneurysm combined with pericardial devascularization. Observation indicators : (1) surgical and postoperative conditions; (2) complications; (3) follow-up. Follow-up was conducted by out-patient examiantion and telephone interview to detect the effect of exclusion of arterial tumor, and blood re-flow, portal vein thrombosis and survival of patients 3 months after operation. The follow-up was up to December 2020. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M(range). Results:(1) Surgical and postoperative conditions. All 17 patients successfully completed the operation, without perioperative death. The operation time, volume of intraoperative blood loss of 17 patients were (181±30)minutes, 187(range, 90?420)mL. The white blood cell count, red blood cell count, hemoglobin, serum albumin were (9±4)×10 9/L, (3.5±0.9)×10 12/L, (86±17)g/L, (36±7)g/L on the postoperative day 3. Time to postoperative abdominal drainage tube removal and duration of post-operative hospital stay were (7±4)days and (11±4)days. (2) Complications. All 17 patients had ascites after surgery, which were improved after oral treatment with diuretics. There was no complication such as intra-abdominal hemorrhage, gastrointestinal fistula, pleural effusion, infection, abscess formation, fever and vascular embolism. (3) Follow-up. All the 17 patients were followed up for 28.6(range, 7.0?84.0)months. During the follow-up, the splenic aneurysm cavity of all patients was completely isolated, no blood re-flow and no portal vein thrombosis was observed, and no patient died. Conclusion:Totally laparoscopic exclusion of splenic artery aneurysm combined with pericardial devascularization is safe and feasible in the treatment of portal hypertension complicated with splenic aneurysm.

6.
Toxicol Rep ; 8: 657-667, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33868952

RESUMO

Oxidative stress is considered to be one of main pathophysiological mechanisms in myocardial ischemia/reperfusion (I/R) injury. Lycium barbarum polysaccharides (LBP), the main ingredient of Lycium barbarum, have potential antioxidant activity. We aimed to investigate the effects of LBP on myocardial I/R injury and explore the underlying mechanisms. Myocardial I/R group was treated with or without LBP to evaluate oxidative stress markers and the role of Nrf2 signal pathway. Our results showed that I/R increased infarct size and the activities of creatine kinase (CK) and lactate dehydrogenase (LDH) when compared with control group. Meanwhile, the levels of reactive oxygen species (ROS), malondialdehyde (MDA), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were enhanced and the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) were decreased. These changes were associated with a significant increase in myocardial apoptosis, ultimately leading to cardiac dysfunction. LBP reduced infarct size (38.4 ± 2 % versus 19.4 ± 1.8 %, p < 0.05), CK and LDH activities and myocardial apoptotic index. Meanwhile, LBP suppressed the production of ROS and restored redox status. Additionally, LBP increased protein level of nuclear Nrf2 in vivo (2.1 ± 0.3 versus 3.8 ± 0.4, p < 0.05) and in vitro (1.9 ± 0.2 versus 3.8 ± 0.1, p < 0.05) and subsequently upregulated heme oxygenase 1 and NADPH dehydrogenase quinone 1 compared to I/R group. Interestingly, Nrf2 siRNA abolished the protective effects of LBP. LBP suppressed oxidative stress damage and attenuated cardiac dysfunction induced by I/R via activation of the Nrf2 antioxidant signal pathway.

7.
Nucleic Acids Res ; 48(15): 8755-8766, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32621606

RESUMO

The sulfur atom of phosphorothioated DNA (PT-DNA) is coordinated by a surface cavity in the conserved sulfur-binding domain (SBD) of type IV restriction enzymes. However, some SBDs cannot recognize the sulfur atom in some sequence contexts. To illustrate the structural determinants for sequence specificity, we resolved the structure of SBDSpr, from endonuclease SprMcrA, in complex with DNA of GPSGCC, GPSATC and GPSAAC contexts. Structural and computational analyses explained why it binds the above PT-DNAs with an affinity in a decreasing order. The structural analysis of SBDSpr-GPSGCC and SBDSco-GPSGCC, the latter only recognizes DNA of GPSGCC, revealed that a positively charged loop above the sulfur-coordination cavity electrostatically interacts with the neighboring DNA phosphate linkage. The structural analysis indicated that the DNA-protein hydrogen bonding pattern and weak non-bonded interaction played important roles in sequence specificity of SBD protein. Exchanges of the positively-charged amino acid residues with the negatively-charged residues in the loop would enable SBDSco to extend recognization for more PT-DNA sequences, implying that type IV endonucleases can be engineered to recognize PT-DNA in novel target sequences.


Assuntos
Enzimas de Restrição do DNA/genética , Proteínas de Ligação a DNA/genética , DNA/genética , Enxofre/química , Sequência de Aminoácidos/genética , Cristalografia por Raios X , DNA/química , Enzimas de Restrição do DNA/química , Proteínas de Ligação a DNA/química , Escherichia coli/genética , Ligação de Hidrogênio , Ligação Proteica/genética , Domínios Proteicos/genética , Streptomyces/enzimologia
8.
J Biochem Mol Toxicol ; 34(5): e22467, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32040235

RESUMO

Oxidative stress induced by long-term cyclosporine A (CsA) administration is a major cause of chronic nephrotoxicity, which is characterized by tubular atrophy, tubular cell apoptosis, and interstitial fibrosis in the progression of organ transplantation. Although hydrogen-rich water (HRW) has been used to prevent various oxidative stress-related diseases, its underlying mechanisms remain unclear. This study investigated the effects of HRW on CsA-induced nephrotoxicity and its potential mechanisms. After administration of CsA (25 mg/kg/day), rats were treated with or without HRW (12 mL/kg) for 4 weeks. Renal function and vascular activity were investigated. Histological changes in kidney tissues were analyzed using Masson's trichrome and terminal deoxynucleotidyl transferase dUTP nick-end labeling stains. Oxidative stress markers and the activation of the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway were also measured. We found that CsA increased the levels of reactive oxygen species (ROS) and malonaldehyde (MDA), but it reduced glutathione (GSH) and superoxide dismutase (SOD) levels. Such alterations induced vascular dysfunction, tubular atrophy, interstitial fibrosis, and tubular apoptosis. This was evident secondary to an increase in urinary protein, serum creatinine, and blood urea nitrogen, ultimately leading to renal dysfunction. Conversely, HRW decreased levels of ROS and MDA while increasing the activity of GSH and SOD. This was accompanied by an improvement in vascular and renal function. Moreover, HRW significantly decreased the level of Keap1 and increased the expression of Nrf2, NADPH dehydrogenase quinone 1, and heme oxygenase 1. In conclusion, HRW restored the balance of redox status, suppressed oxidative stress damage, and improved kidney function induced by CsA via activation of the Keap1/Nrf2 signaling pathway.


Assuntos
Ciclosporina/efeitos adversos , Hidrogênio/farmacologia , Imunossupressores/efeitos adversos , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Substâncias Protetoras/farmacologia , Insuficiência Renal/induzido quimicamente , Transdução de Sinais/efeitos dos fármacos , Água/farmacologia , Animais , Apoptose/efeitos dos fármacos , Nitrogênio da Ureia Sanguínea , Creatinina/sangue , Creatinina/urina , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Insuficiência Renal/urina , Superóxido Dismutase/metabolismo , Água/química
9.
Cell Tissue Bank ; 20(4): 557-568, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31583486

RESUMO

The purpose of this paper is to analyze the properties of porcine cartilage type II collagen scaffolds crosslinked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxy-succinamide (EDC/NHS) under different conditions. The porous EDC/NHS-crosslinked scaffolds were obtained through a two-step freeze-drying process. To determine the optimal crosslinking condition, we used different solvents and various crosslinking temperatures to prepare the scaffolds. Three crosslinking solutions were prepared with different solvents, photographs were taken with a flash in the darkroom, and light transmission was observed. Type II collagen was crosslinked on a horizontal shaker at a speed of 60 r/min according to the above grouping conditions, and then the structural change of the scaffold in each group was observed. To investigate the swelling ratio and the in vitro degradation of the collagen scaffold, tests were also carried out by immersion of the scaffolds in a PBS solution and digestion in type II collagenase, respectively. The influence of the scaffolds on the proliferation of chondrocytes was assessed by the methyl thiazolyl tetrazolium colorimetric assay. The morphology of the crosslinked scaffolds cocultured with chondrocytes was characterized by a scanning electron microscope. The results proved that 75% alcohol and a crosslinking temperature of 37 °C are recommended. Collagen fibrils are more densely packed after crosslinking with EDC/NHS and have a more uniform structure than that of noncrosslinked ones. The EDC-crosslinked scaffolds possessed excellent mechanical property and biocompatibility.


Assuntos
Colágeno Tipo II/química , Reagentes de Ligações Cruzadas/química , Succinimidas/química , Alicerces Teciduais/química , Animais , Proliferação de Células , Células Cultivadas , Condrócitos/citologia , Liofilização , Coelhos , Suínos , Engenharia Tecidual
10.
Natl Sci Rev ; 6(1): 145-154, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34691840

RESUMO

In this paper, we will give a general introduction to the Ali CMB Polarization Telescope (AliCPT) project, which is a Sino-US joint project led by the Institute of High Energy Physics and involves many different institutes in China. It is the first ground-based Cosmic Microwave Background (CMB) polarization experiment in China and an integral part of China's Gravitational-wave Program. The main scientific goal of the AliCPT project is to probe the primordial gravitational waves (PGWs) originating from the very early Universe. The AliCPT project includes two stages. The first stage, referred to as AliCPT-1, is to build a telescope in the Ali region of Tibet at an altitude of 5250 meters. Once completed, it will be the highest ground-based CMB observatory in the world and will open a new window for probing PGWs in the northern hemisphere. The AliCPT-1 telescope is designed to have about 7000 transition-edge sensor detectors at 95 GHz and 150 GHz. The second stage is to have a more sensitive telescope (AliCPT-2) with more than 20 000 detectors. Our simulations show that AliCPT will improve the current constraint on the tensor-to-scalar ratio r by one order of magnitude with three years' observation. Besides the PGWs, AliCPT will also enable a precise measurement of the CMB rotation angle and provide a precise test of the CPT symmetry. We show that three years' observation will improve the current limit by two orders of magnitude.

11.
World J Clin Cases ; 7(24): 4226-4233, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31911903

RESUMO

BACKGROUND: Branches of the lateral circumflex femoral artery (LCFA) stretch across the surgical field during a direct anterior total hip arthroplasty. It is an anatomical marker in direct anterior approach. As an important vessel around the hip joint, this vessel was ligated in most situations. Although ligation of the vascular pedicle of the LCFA is a common, traditional procedure used to decrease bleeding, the ligation of the pedicle of the vessel is tedious and time-consuming. AIM: To explore whether this ligation is truly necessary in a direct anterior approach to total hip arthroplasty. METHODS: This single-center, single-surgeon, prospective study was performed to compare patients' bleeding undergoing ligation of the branches of the LCFA pedicle (group A) vs those treated with electrocautery from the branches of the LCFA (group B). In both groups, the pedicles were identified in the intermuscular plane between the tensor fasciae lata and the rectus femoris muscles. In group A, the pedicles were ligated with a silk ligature. In group B, the branches coming off the LCFA were controlled with electrocautery. We compared preoperative vs postoperative changes in blood hemoglobin levels, intraoperative blood loss, operative time, rates of transfusion, re-bleeding, and hematoma between the two groups. RESULTS: The reduction of hemoglobin in group A was 20.9 ± 7.0, and in group B it was 21.2 ± 4.9. There was no statistically significant difference between the two groups (P > 0.05). The actual calculated blood loss in group A was 784 ± 125 mL, and in group B it was 722 ± 153 mL. There was a trend in group A having more blood loss (P = 0.078). The estimated blood loss in group A was 344 ± 88 mL, and in group B it was 346 ± 73 mL. There was no statistically significant difference between the two groups (P = 0.883). In addition, there were no significant differences in the rates of postoperative transfusion (10% vs 6.7%, P > 0.05), postoperative hematomas (6.7% vs 13.3%, P > 0.05), or re-bleeding (13.3% vs 20%, P > 0.05) between the two groups. CONCLUSION: Ligation of the pedicle of the LCFA has no advantage in preventing or decreasing bleeding during or after a total hip arthroplasty using the direct anterior approach. Ligation of the pedicle of the vessel is a cumbersome, unnecessary procedure and can be replaced by electrocautery control of the branches off this artery that course through the surgical field.

12.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-797809

RESUMO

Objective@#To explore the application value of laparoscopic gastric plication (LGP) combined with duodeno-jejunal omega switch (DJOS) in modified adjustable gastric banding.@*Methods@#The retrospective and descriptive study was conducted. The clinical data of a female 46-year-old patient who had failure to undergo the adjustable gastric banding in the Hospital of Ludwig Maximilian University from December 2016 to December 2018 were collected. LGP and DJOS were performed in two-stages after completion of preoperative examinations. Observation indicators: (1) surgical and postoperative situations; (2) follow-up. Follow-up using outpatient examiantion and telephone interview was performed to collect the information of body mass index (BMI), insulin therapy, and long-term complications until December 2018. Count data were represented as absolute numbers.@*Results@#(1) Surgical and postoperative situations: the patient underwent LGP in the first stage and DJOS in the second stage successfully. For the LGP, the operation time, time of intestinal reconstruction, volume of intraoperative blood loss, time to first flatus, time to drainage tube removal, time to resume to normal diet, and duration of postoperative hospital stay were 96 minutes, 58 minutes, 210 mL, 32 hours, 48 hours, 42 days, and 3 days, respectively. For the DJOS, the above indicators were 148 minutes, 117 minutes, 260 mL, 47 hours, 72 hours, 21 days, and 7 days, respectively. There was no complication occurred in either LGP or DJOS. (2) Follow-up: the patient was followed up for 24 months after LGP. The BMI of this patient decreased to 45.3 kg/m2 at 6 months after LGP, and decreased to 37.2 kg/m2 at 18 months after DJOS. Insulin therapy was discontinued. There was no long-term complication such as malnutrition, dumping syndrome, or biliary reflux.@*Conclusion@#LGP combined with DJOS can enrich treatment methods of obese patient with BMI >50 kg/m2, which offers a safer surgical procedure option for patients after gastric binding.

13.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-790091

RESUMO

Objective To explore the application value of laparoscopic gastric plication (LGP) combined with duodeno-jejunal omega switch (DJOS) in modified adjustable gastric banding.Methods The retrospective and descriptive study was conducted.The clinical data of a female 46-year-old patient who had failure to undergo the adjustable gastric banding in the Hospital of Ludwig Maximilian University from December 2016 to December 2018 were collected.LGP and DJOS were performed in two-stages after completion of preoperative examinations.Observation indicators:(1) surgical and postoperative situations;(2) follow-up.Follow-up using outpatient examiantion and telephone interview was performed to collect the information of body mass index (BMI),insulin therapy,and long-term complications until December 2018.Count data were represented as absolute numbers.Results (1) Surgical and postoperative situations:the patient underwent LGP in the first stage and DJOS in the second stage successfully.For the LGP,the operation time,time of intestinal reconstruction,volume of intraoperative blood loss,time to first flatus,time to drainage tube removal,time to resume to normal diet,and duration of postoperative hospital stay were 96 minutes,58 minutes,210 mL,32 hours,48 hours,42 days,and 3 days,respectively.For the DJOS,the above indicators were 148 minutes,117 minutes,260 mL,47 hours,72 hours,21 days,and 7 days,respectively.There was no complication occurred in either LGP or DJOS.(2) Follow-up:the patient was followed up for 24 months after LGP.The BMI of this patient decreased to 45.3 kg/m2 at 6 months after LGP,and decreased to 37.2 kg/m2 at 18 months after DJOS.Insulin therapy was discontinued.There was no long-term complication such as malnutrition,dumping syndrome,or biliary reflux.Conclusion LGP combined with DJOS can enrich treatment methods of obese patient with BMI >50 kg/m2,which offers a safer surgical procedure option for patients after gastric binding.

14.
Mol Microbiol ; 110(3): 484-497, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30184284

RESUMO

Streptomyces species have been valuable models for understanding the phenomenon of DNA phosphorothioation in which sulfur replaces a non-bridging oxygen in the phosphate backbone of DNA. We previously reported that the restriction endonuclease ScoMcrA from Streptomyces coelicolor cleaves phosphorothioate DNA and Dcm-methylated DNA at sites 16-28 nucleotides away from the modification sites. However, cleavage of modified DNA by ScoMcrA is always incomplete and accompanied by severe promiscuous activity on unmodified DNA. These features complicate the studies of recognition and cleavage of phosphorothioate DNA. For these reasons, we here characterized SprMcrA from Streptomyces pristinaespiralis, a much smaller homolog of ScoMcrA with a rare HRH motif, a variant of the HNH motif that forms the catalytic center of these endonucleases. The sulfur-binding domain of SprMcrA and its phosphorothioation recognition site were determined. Compared to ScoMcrA, SprMcrA has higher specificity in discerning phosphorothioate DNA from unmodified DNA, and this enzyme generally cuts both strands at a distance of 11-14 nucleotides from the 5' side of the recognition site. The HRH/HNH motif has its own sequence specificity in DNA hydrolysis, leading to failure of cleavage at some phosphorothioated sites. An R248N mutation of the central residue in HRH resulted in 30-fold enhancement in cleavage activity of phosphorothioate DNA and altered the cleavage efficiency at some sites, whereas mutation of both His residues abolished restriction activity. This is the first report of a recognition domain for phosphorothioate DNA and phosphorothioate-dependent and sequence-specific restriction activity.


Assuntos
Enzimas de Restrição do DNA/metabolismo , DNA Bacteriano/metabolismo , Streptomyces/enzimologia , Enxofre/metabolismo , Sítios de Ligação , Ligação Proteica
15.
Phys Rev Lett ; 118(18): 181301, 2017 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-28524695

RESUMO

The morphological properties of the large scale structure of the Universe can be fully described by four Minkowski functionals (MFs), which provide important complementary information to other statistical observables such as the widely used 2-point statistics in configuration and Fourier spaces. In this work, for the first time, we present the differences in the morphology of the large scale structure caused by modifications to general relativity (to address the cosmic acceleration problem), by measuring the MFs from N-body simulations of modified gravity and general relativity. We find strong statistical power when using the MFs to constrain modified theories of gravity: with a galaxy survey that has survey volume ∼0.125(h^{-1} Gpc)^{3} and galaxy number density ∼1/(h^{-1} Mpc)^{3}, the two normal-branch Dvali-Gabadadze-Porrati models and the F5 f(R) model that we simulated can be discriminated from the ΛCDM model at a significance level ≳5σ with an individual MF measurement. Therefore, the MF of the large scale structure is potentially a powerful probe of gravity, and its application to real data deserves active exploration.

16.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-607147

RESUMO

Objective To investigate the safety and efficacy of stent insertion combined with high-intensity focused ultrasound(HIFU) ablation for malignant obstructive jaundice caused by pancreatic carcinoma.Methods From January 2013 to February 2017,a total of 80 patients with malignant obstructive jaundice caused by pancreatic carcinoma underwent biliary stent insertion in our center,who were divided into combined treatment(stent insertion with HIFU ablation) group(n=38) and solitary stent insertion group(n=42).The stent patency time and survival time were compared between the two groups.Results Relief of jaundice were archived in all patients in both groups.Cholangitis was observed in 7 cases in both two groups.Reobstruction of stent was observed in 15 patients in both two groups.The median stent patency time was 179 days in combined treatment group and 119 days in solitary stent insertion group(P<0.01);the median survival time was 209 days in combined treatment group and 145 days in solitary stent insertion group,the differences were significant(P<0.01).Based on the univariate and multivariate Cox regression analyses,the predictors of prolonging survival included subsequent HIFU ablation after stent insertion and earlier tumor stage(P<0.05).Conclusion Combined biliary stent insertion and HIFU ablation is a safe and effective method for malignant obstructive jaundice caused by pancreatic carcinoma,and seems to extend stent patency time and survival when compared with biliary stent only.

17.
Sci Rep ; 6: 39675, 2016 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-28000775

RESUMO

Modified pyrimidine monophosphates such as methyl dCMP (mdCMP), hydroxymethyl dUMP (hmdUMP) and hmdCMP in some phages are synthesized by a large group of enzymes termed as thymidylate synthases (TS). Thymidylate is a nucleotide required for DNA synthesis and thus TS is an important drug target. In the biosynthetic pathway of the nucleoside fungicide mildiomycin isolated from Streptomyces rimofaciens ZJU5119, a cytidylate (CMP) hydroxymethylase, MilA, catalyzes the conversion of CMP into 5'-hydroxymethyl CMP (hmCMP) with an efficiency (kcat/KM) of 5-fold faster than for deoxycytidylate (dCMP). MilA is thus the first enzyme of the TS superfamily preferring CMP to dCMP. Here, we determined the crystal structures of MilA and its complexes with various substrates including CMP, dCMP and hmCMP. Comparing these structures to those of dCMP hydroxymethylase (CH) from T4 phage and TS from Escherichia coli revealed that two residues in the active site of CH and TS, a serine and an arginine, are respectively replaced by an alanine and a lysine, Ala176 and Lys133, in MilA. Mutation of A176S/K133R of MilA resulted in a reversal of substrate preference from CMP to dCMP. This is the first study reporting the evolution of the conserved TS in substrate selection from DNA metabolism to secondary nucleoside biosynthesis.


Assuntos
Proteínas de Bactérias/metabolismo , Monofosfato de Citidina/metabolismo , Citosina/análogos & derivados , Desoxicitidina/química , Streptomyces/química , Timidilato Sintase/metabolismo , Alanina/química , Sítios de Ligação , Domínio Catalítico , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Cristalografia por Raios X , Citosina/biossíntese , Cinética , Lisina/química , Espectrometria de Massas , Mutagênese Sítio-Dirigida , Mutação , Ribose/química , Especificidade por Substrato
18.
Phys Rev Lett ; 117(5): 051101, 2016 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-27517761

RESUMO

In this Letter, we report the observational constraints on the Hu-Sawicki f(R) theory derived from weak lensing peak abundances, which are closely related to the mass function of massive halos. In comparison with studies using optical or x-ray clusters of galaxies, weak lensing peak analyses have the advantages of not relying on mass-baryonic observable calibrations. With observations from the Canada-France-Hawaii-Telescope Lensing Survey, our peak analyses give rise to a tight constraint on the model parameter |f_{R0}| for n=1. The 95% C.L. is log_{10}|f_{R0}|<-4.82 given WMAP9 priors on (Ω_{m}, A_{s}). With Planck15 priors, the corresponding result is log_{10}|f_{R0}|<-5.16.

19.
Phys Rev Lett ; 116(17): 171301, 2016 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-27176512

RESUMO

Sound waves from the primordial fluctuations of the Universe imprinted in the large-scale structure, called baryon acoustic oscillations (BAOs), can be used as standard rulers to measure the scale of the Universe. These oscillations have already been detected in the distribution of galaxies. Here we propose to measure BAOs from the troughs (minima) of the density field. Based on two sets of accurate mock halo catalogues with and without BAOs in the seed initial conditions, we demonstrate that the BAO signal cannot be obtained from the clustering of classical disjoint voids, but it is clearly detected from overlapping voids. The latter represent an estimate of all troughs of the density field. We compute them from the empty circumsphere centers constrained by tetrahedra of galaxies using Delaunay triangulation. Our theoretical models based on an unprecedented large set of detailed simulated void catalogues are remarkably well confirmed by observational data. We use the largest recently publicly available sample of luminous red galaxies from SDSS-III BOSS DR11 to unveil for the first time a >3σ BAO detection from voids in observations. Since voids are nearly isotropically expanding regions, their centers represent the most quiet places in the Universe, keeping in mind the cosmos origin and providing a new promising window in the analysis of the cosmological large-scale structure from galaxy surveys.

20.
The Journal of Practical Medicine ; (24): 566-568,569, 2016.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-603207

RESUMO

Objective To investigate the expression of microRNA (miRNA) in placenta tissue, explore the function of miRNA in pathogenesis of gestational diabetes mellitus (GDM). Methods Placenta tissue from pregnant women with GDM and normal controls were selected from January 2013 to January 2014. Expression of miRNAs were detected by sequencing technique and quantity real time PCR(qRT-PCR). Target genes of miRNA were analyzed by KEGG. Results 52 insulin signaling pathway related miRNAs including 47 up-regulated and 5 down-regulated were differentially expressed in GDM compared with normal control. Expression of placental hsa-miR-548am-5p and hsa-miR-95-5p were significantly increased , but hsa-miR-1246 was significantly lower (P <0.05) in GDM group than normal control; all the results were consistent with sequencing results. Key points of insulin signaling pathway could regulate expression of targets such as PI3K. Conclusion miRNA expression in GDM placenta was abnormal.A variety of exp ressions of miRNAs were involved in the pathogenesis of GDM by regulating insulin signaling pathway.

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