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1.
Immunity ; 44(2): 355-67, 2016 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-26872699

RESUMO

Normal repair of skeletal muscle requires local expansion of a special population of Foxp3(+)CD4(+) regulatory T (Treg) cells. Such cells failed to accumulate in acutely injured muscle of old mice, known to undergo ineffectual repair. This defect reflected reduced recruitment of Treg cells to injured muscle, as well as less proliferation and retention therein. Interleukin-33 (IL-33) regulated muscle Treg cell homeostasis in young mice, and its administration to old mice ameliorated their deficits in Treg cell accumulation and muscle regeneration. The major IL-33-expressing cells in skeletal muscle displayed a constellation of markers diagnostic of fibro/adipogenic progenitor cells and were often associated with neural structures, including nerve fibers, nerve bundles, and muscle spindles, which are stretch-sensitive mechanoreceptors important for proprioception. IL-33(+) cells were more frequent after muscle injury and were reduced in old mice. IL-33 is well situated to relay signals between the nervous and immune systems within the muscle context.


Assuntos
Envelhecimento/imunologia , Interleucina-33/metabolismo , Músculo Esquelético/fisiologia , Células-Tronco/imunologia , Linfócitos T Reguladores/imunologia , Adipogenia/imunologia , Animais , Biomarcadores/metabolismo , Proliferação de Células , Células Cultivadas , Homeostase , Humanos , Mecanotransdução Celular , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Esquelético/inervação , Fibras Nervosas/fisiologia , Neuroimunomodulação , Regeneração/imunologia , Cicatrização
2.
Eur Phys J E Soft Matter ; 47(3): 18, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38457022

RESUMO

The viscoelasticity of a carbon nanotube (CNT)-laden air-water interface was characterized using two different experimental methods. The first experimental method used a Langmuir-Pockels (LP) trough coupled with a pair of oscillating barriers. The second method is termed the Bicone-Trough (BT) method, where a LP trough was custom-built and fit onto a rheometer equipped with a bicone fixture to standardize the preparation and conditioning of a particle-laden interface especially at high particle coverages. The performance of both methods was evaluated by performing Fast Fourier Transform (FFT) analysis to calculate the signal-to-noise ratios (SNR). Overall, the rheometer-based BT method offered better strain control and considerably higher SNRs compared to the Oscillatory Barriers (OB) method that oscillated barriers with relatively limited positional and speed control. For a CNT surface coverage of 165 mg/m2 and a frequency of 100 mHz, the interfacial shear modulus obtained from the OB method increased from 39 to 57 mN/m as the normal strain amplitude increased from 1 to 3%. No linear viscoelastic regime was experimentally observed for a normal strain as small as 0.5%. In the BT method, a linear regime was observed below a shear strain of 0.1%. The interfacial shear modulus decreased significantly from 96 to 2 mN/m as the shear strain amplitude increased from 0.025 to 10%.

3.
S Afr J Psychiatr ; 30: 2222, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38628902

RESUMO

Background: Women charged with violent offences may be referred by courts for forensic psychiatric assessment to determine whether mental disorder or intellectual disability impacts their fitness to stand trial and/or criminal responsibility. The profile of these women is a poorly researched area in South Africa. Aim: This study examined the socio-demographic, offence-related, and clinical profile of South African women charged with violent offences referred for forensic assessment. Setting: Fort England Hospital (FEH), a forensic psychiatric institution in the Eastern Cape. Methods: The clinical records of 173 women referred by courts for forensic psychiatric evaluation over a 24-year period (1993-2017) to FEH were systematically reviewed. Results: Most women were single, black mothers with dependent children, who were unemployed and socio-economically impoverished. Many had backgrounds of pre-offence mental illness, alcohol use and alleged abuse. The majority were first-time offenders whose victims were known to them. Most child victims were biological children killed by their mothers. Likely primary motives for violence were related to psychopathology in half of cases, and interpersonal conflict in a third. Forensic assessment most frequently confirmed psychotic disorders and dual diagnoses. Half the cases were fit to stand trial and under half were criminally responsible. Conclusion: Violent female offending occurs within a gendered context, with high rates of prior trauma, alcohol use and psychosocial distress in perpetrators. An emphasis on gender-sensitive psychosocial interventions is required. Contribution: This study highlights the nature and context of violent offending by women referred for forensic psychiatric assessment in South Africa.

4.
Inorg Chem ; 61(13): 5201-5214, 2022 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-35073478

RESUMO

Mercury is in some sense an enigmatic element. The element and some of its compounds are a natural part of the biogeochemical cycle; while many of these can be deadly poisons at higher levels, environmental levels in the absence of anthropogenic contributions would generally be below the threshold for concern. However, mercury pollution, particularly from burning fossil fuels such as coal, is providing dramatic and increasing emissions into the environment. Because of this, the environmental chemistry and toxicology of mercury are of growing importance, with the fate of mercury being vitally dependent upon its speciation. X-ray absorption spectroscopy (XAS) provides a powerful tool for in situ chemical speciation, but is severely limited by poor spectroscopic energy resolution. Here, we provide a systematic examination of mercury Lα1 high energy resolution fluorescence detected XAS (HERFD-XAS) as an approach for chemical speciation of mercury, in quantitative comparison with conventional Hg LIII-edge XAS. We show that, unlike some lighter elements, chemical shifts in the Lα1 X-ray fluorescence energy can be safely neglected, so that mercury Lα1 HERFD-XAS can be treated simply as a high-resolution version of conventional XAS. We present spectra of a range of mercury compounds that may be relevant to the environmental and life science research and show that density functional theory can produce adequate simulations of the spectra. We discuss strengths and limitations of the method and quantitatively demonstrate improvements both in speciation for complex mixtures and in background rejection for low concentrations.


Assuntos
Mercúrio , Espectroscopia por Absorção de Raios X
5.
Afr J Reprod Health ; 25(1): 114-121, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34077117

RESUMO

The high rate of foetal alcohol spectrum disorders, which results from alcohol consumption during pregnancy, is of concern in South Africa. The aims of this research were to establish the prevalence, patterns and factors associated with alcohol use amongst pregnant women attending antenatal clinics in two former township areas of Buffalo City, South Africa. A survey was conducted using a structured questionnaire that included socio-demographic questions, and the Alcohol Use Test (AUDIT). The questionnaire was administered in English, Afrikaans or isiXhosa by healthcare providers trained in its administration. Consecutive sampling was used, with all willing women presenting at public clinics offering antenatal care in the two townships being invited to participate. Of the 18 clinics operating in the two townships, 16 were willing to participate, resulting in a sample of 1028 women over a nine-month period. Data were analysed in Medcalc using descriptive statistics, one-way analysis of variance, independent samples t-test and a multivariable binary logistic regression analysis. Two-thirds of the sample did not drink alcohol, but results showed high levels of risky alcohol use: 20.1% on the total AUDIT scale, and 16.8% on the AUDIT-C scale. The following variables were found to be significantly associated with risky drinking: age; race; report of intimate partner violence (IPV); and other regular drinker in the home. Employment status, education status, relationship status, parity and gestation were not associated with risky drinking. Interventions aimed at reducing alcohol use during pregnancy should address: drinking youth cultures; drinking norms within the home; and intimate partner violence. Future studies should include additional mental and physical health variables.


Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Violência por Parceiro Íntimo/psicologia , Gestantes/psicologia , Adolescente , Adulto , Consumo de Bebidas Alcoólicas/psicologia , Feminino , Humanos , Violência por Parceiro Íntimo/estatística & dados numéricos , Gravidez , Cuidado Pré-Natal , Prevalência , Fatores de Risco , Fatores Socioeconômicos , África do Sul/epidemiologia , Inquéritos e Questionários , Adulto Jovem
6.
Inorg Chem ; 59(23): 16824-16828, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-33200921

RESUMO

The synthesis, properties, X-ray structures, and catalytic sulfur-atom-transfer (SAT) reactions of W2(µ-S)(µ-S2)(dtc)2(dped)2 [1; dtc = S2CNR2-, where R = Me, Et, iBu, and Bn; dped = S2C2Ph22-] and W2(µ-S)2(dtc)2(dped)2 (2) are reported. These complexes represent the oxidized (1) and reduced (2) forms of anaerobic SAT catalysts operating through the bidirectional, ligand-based half-reaction (µ-S)(µ-S2) ↔ (µ-S)2 + S0. The catalysts are deactivated in air through the formation of catalytically inactive oxo complexes, (dtc)WO(µ-S)(µ-dped)W(dtc)(dped) (3), prompting us to recommend that group 6 SAT activity be assessed under strictly anaerobic conditions.

7.
Environ Sci Technol ; 54(24): 15946-15957, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33258596

RESUMO

The use of nontherapeutic broad-spectrum antimicrobial agents triclosan (TCS) and benzalkonium chloride (BC) can contribute to bacterial resistance to clinically relevant antibiotics. Antimicrobial-resistant bacteria within wastewater may reflect the resistance burden within the human microbiome, as antibiotics and pathogens in wastewater can track with clinically relevant parameters during perturbations to the community. In this study, we monitored culturable and resistant wastewater bacteria and cross-resistance to clinically relevant antibiotics to gauge the impact of each antimicrobial and identify factors influencing cross-resistance profiles. Bacteria resistant to TCS and BC were isolated from wastewater influent over 21 months, and cross-resistance, taxonomy, and monthly changes were characterized under both antimicrobial selection regimes. Cross-resistance profiles from each antimicrobial differed within and between taxa. BC-isolated bacteria had a significantly higher prevalence of resistance to "last-resort antibiotic" colistin, while isolates resistant to TCS exhibited higher rates of multidrug resistance. Prevalence of culturable TCS-resistant bacteria decreased over time following Food and Drug Administration (FDA) TCS bans. Cross-resistance patterns varied according to sampling date, including among the most clinically important antibiotics. Correlations between strain-specific resistance profiles were largely influenced by taxonomy, with some variations associated with sampling date. The results reveal that time, taxonomy, and selection by TCS and BC impact features of cross-resistance patterns among diverse wastewater microorganisms, which could reflect the variety of factors influencing resistance patterns relevant to a community microbiome.


Assuntos
Anti-Infecciosos , Águas Residuárias , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Bactérias , Farmacorresistência Bacteriana , Resistência a Múltiplos Medicamentos , Humanos , Testes de Sensibilidade Microbiana
8.
Clin Infect Dis ; 69(3): 421-427, 2019 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-30403768

RESUMO

BACKGROUND: Infection with the gram-negative bacterium Burkholderia pseudomallei can result in melioidosis, a life-threatening disease that can be difficult to diagnose. Culture remains the gold standard for diagnosis but requires laboratory resources not available in many endemic regions. A lateral flow immunoassay has shown promise for POC diagnostics but suffers from low sensitivity when used on blood samples. PCR also has low sensitivity on blood, attributed to the low bacterial numbers in blood observed in melioidosis patients, even when bacteraemic. METHODS: A prototype i-STAT cartridge was developed to utilize the monoclonal antibody specific for the capsule of pathogenic Burkholderia species employed on the LFI. The resulting POC assay was evaluated on 414 clinical specimens from Darwin, Australia and Cambodia. RESULTS: The i-STAT assay accurately distinguished Australian blood culture positive melioidosis patients from Australian patients hospitalized with other infections (AUC = 0.91, 95% CI 0.817 - 1.0). We derived an assay cutoff with 76% sensitivity and 94% specificity that correctly classified 88% (n = 74) of the Australian patients. Interestingly, only 46% (6/13) of the culture-positive melioidosis patients in Cambodia were classified correctly. Of great importance however, the assay detected capsule from blood samples for 32% of blood culture negative melioidosis patients in both cohorts and previously undiagnosed melioidosis patients in Cambodia. In addition the assay showed high sensitivity and specificity for urine, pus and sputum. CONCLUSIONS: Diagnostic tools that are not dependent upon the growth kinetics or the levels of bacteremia of B. pseudomallei represent the next-generation of diagnostics and must be pursued further.


Assuntos
Anticorpos Monoclonais/imunologia , Burkholderia pseudomallei/imunologia , Imunoensaio/instrumentação , Melioidose/diagnóstico , Testes Imediatos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos de Bactérias/imunologia , Austrália , Biomarcadores/sangue , Hemocultura , Camboja , Feminino , Humanos , Imunoensaio/métodos , Masculino , Melioidose/imunologia , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Adulto Jovem
9.
J Chem Phys ; 151(12): 124907, 2019 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-31575212

RESUMO

The dynamics and rheology of semidilute polymer solutions in strong flows are of great practical relevance. Processing applications can in principle be designed utilizing the relationship between nonequilibrium polymer conformations and the material properties of the solution. However, the interplay between concentration, flow, hydrodynamic interactions (HIs), and topological interactions which govern semidilute polymer dynamics is challenging to characterize. Brownian dynamics (BD) simulations are particularly valuable as a way to directly visualize how molecular interactions arise in these systems and are quantitatively comparable to single-molecule experiments. However, such simulations are often computationally intractable and are limited by the need to calculate the correlated Brownian noise via decomposition of the diffusion tensor. Previously, we have introduced an iterative conformational averaging (CA) method for BD simulations which bypasses these limitations by preaveraging the HI and Brownian noise in an iterative procedure. In this work, we generalize the CA method to flowing semidilute solutions by introducing a conformation dependent diffusion tensor and a strain dependent approximation to the conformationally averaged Brownian noise. We find that this approach nearly quantitatively reproduces both transient and steady state polymer dynamics and rheology while achieving an order of magnitude computational acceleration. We then utilize the CA method to investigate the concentration and flow rate dependence of polymer dynamics in planar extensional flows. Our results are consistent with previous experimental and simulation studies and provide a detailed view of broad conformational distributions in the semidilute regime. We observe interconversion between stretched and coiled states at steady state, which we conjecture occur due to the effect of concentration on the conformation dependent polymer drag. Additionally, we observe transient flow-induced intermolecular hooks in the startup of flow which lead to diverse and unique stretching pathways.

10.
Immunogenetics ; 70(9): 553-562, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29862454

RESUMO

Mastitis is a detrimental disease in the dairy industry that decreases milk quality and costs upwards of $2 billion annually. Often, mastitis results from bacteria entering the gland through the teat opening. Streptococcus uberis is responsible for a high percentage of subclinical and clinical mastitis. Following an intramammary experimental challenge with S. uberis on Holstein cows (n = 40), milk samples were collected and somatic cell counts (SCC) were determined by the Dairy Herd Improvement Association Laboratory. Traditional genome-wide association studies (GWAS) have utilized test day SCC or SCC lactation averages to identify loci of interest. Our approach utilizes SCC collected following a S. uberis experimental challenge to generate three novel phenotypes: (1) area under the curve (AUC) of SCC for 0-7 days and (2) 0-28 days post-challenge; and (3) when SCC returned to below 200,000 cells/mL post-challenge (< 21 days, 21-28 days, or > 28 days). Polymorphisms were identified using Illumina's BovineSNP50 v2 DNA BeadChip. Associations were tested using Plink software and identified 16 significant (p < 1.0 × 10-4) single-nucleotide polymorphisms (SNPs) across the phenotypes. Most significant SNPs were in genes linked to cell signaling, migration, and apoptosis. Several have been recognized in relation to infectious processes (ATF7, SGK1, and PACRG), but others less so (TRIO, GLRA1, CELSR2, TIAM2, CPE). Further investigation of these genes and their roles in inflammation (e.g., SCC) can provide potential targets that influence resolution of mammary gland infection. Likewise, further investigation of the identified SNP with mastitis and other disease phenotypes can provide greater insight to the potential of these SNP as genetic markers.


Assuntos
Leucócitos/fisiologia , Mastite Bovina/genética , Mastite Bovina/microbiologia , Polimorfismo de Nucleotídeo Único , Infecções Estreptocócicas/veterinária , Animais , Bovinos , Feminino , Estudo de Associação Genômica Ampla , Leite/citologia , Fenótipo , Infecções Estreptocócicas/genética , Infecções Estreptocócicas/microbiologia , Streptococcus/patogenicidade
11.
Biochim Biophys Acta Mol Basis Dis ; 1864(5 Pt A): 1622-1633, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29410027

RESUMO

Anterior gradient 2 (AGR2), an endoplasmic reticulum (ER)-resident protein-disulfide isomerase (PDI), is associated with cancer development and malignant progression. Here, we show that high level of AGR2 promotes the aggressive phenotype of prostate cancer (PCa) mouse models developed by either patient-derived xenografts or surgical intra-prostate implantation of PCa cells, associated with enrichment of the blood vessel network in tumor tissues. Angiogenesis markers VEGFR2 and CD34, accompanied with the invasive marker Vimentin, were predominantly stained in metastatic liver tissues. Secreted AGR2 was defined to enhance VEGFR2 activity as evidenced by physical interaction of purified recombinant human AGR2 (rhAGR2) with rhVEGFA through the formation of a disulfide bond. Mutant or deleted thioredoxin motif in rhAGR2 was also unable to bind to rhVEGFA that led to the significant abolishment in the vessel formation, but partially affecting the aggressive process, implicating alternative mechanisms are required for AGR2-conferring metastasis. Cytosolic AGR2 contributed to cell metastasis ascribed to its stabilizing effect on p65 protein, which subsequently activated the NF-κB and facilitated epithelial to mesenchymal transition (EMT). Importantly, GSH and cabozantinib, but not bevacizumab, effectively blocked the pro-angiogenic effect of rhAGR2 in vitro and in vivo, providing evidence that secreted AGR2 acts as a predictive biomarker for selection of angiogenesis-targeting therapeutic drugs based on its levels in the circular system.


Assuntos
Bevacizumab/farmacologia , Proteínas de Neoplasias , Neovascularização Patológica , Neoplasias da Próstata , Proteínas , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição RelA , Fator A de Crescimento do Endotélio Vascular , Animais , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Mucoproteínas , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Proteínas Oncogênicas , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Proteínas/genética , Proteínas/metabolismo , Proteínas/farmacologia , Transdução de Sinais/genética , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
12.
J Chem Phys ; 149(17): 174904, 2018 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-30408996

RESUMO

The dynamics of semidilute polymer solutions are important to many polymer solution processing techniques such as fiber spinning and solution printing. The out-of-equilibrium molecular conformations resulting from processing flows directly impact material properties. Brownian dynamics (BD) simulations are a standard technique for studying this connection between polymer conformations in solution and processing flows because they can capture molecular-level polymer dynamics. However, BD simulations of semidilute polymer solutions are computationally limited by the calculation of hydrodynamic interactions (HIs) via an Ewald summed diffusion tensor and stochastic Brownian displacements via the decomposition of the diffusion tensor. Techniques based on the Cholesky decomposition scale with the number of particles N as O(N 3) and approximations in the literature have reduced this scaling to as low as O(N). These methods still require continuous updating of the diffusion tensor and Brownian displacements, resulting in a significant constant per-time step cost. Previously, we introduced a method that avoids this cost for dilute polymer solutions by iterative conformational averaging (CA) of intramolecular HIs. In this work, we extend the CA method to semidilute solutions by introducing a grid-space average of intermolecular HIs and a pairwise approximation to the Brownian displacements based on the truncated expansion ansatz of Geyer and Winter. We evaluate our method by first comparing the computational cost with that of other simulation techniques. We verify our approximations by comparison with expected results for static and dynamic properties at equilibrium and use our method to demonstrate the concentration dependence of HI screening.

13.
Inorg Chem ; 56(9): 5189-5202, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28414431

RESUMO

Orange Tp*WSCl2 has been synthesized from the reactions of Tp*WOCl2 with boron sulfide in refluxing toluene or Tp*WS2Cl with PPh3 in dichloromethane at room temperature. Mononuclear sulfido-tungsten(V) complexes, Tp*WSXY {X = Y = Cl, OPh, SPh, SePh; X = Cl, Y = OPh; XY = toluene-3,4-dithiolate (tdt), quinoxaline-2,3-dithiolate (qdt); and Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate} were prepared by metathesis of Tp*WSCl2 with the respective alkali metal salt of X-/XY2-, or [NHEt3]2(qdt). The complexes were characterized by microanalysis, mass spectrometry, electrochemistry, and infrared (IR), electron paramagnetic resonance (EPR) and electronic absorption spectroscopies. The molecular structures of Tp*WS(OPh)2, Tp*WS(SePh)2, and Tp*WS(tdt) have been determined by X-ray crystallography. The six-coordinate, distorted-octahedral W centers are coordinated by terminal sulfido (W≡S = 2.128(2) - 2.161(1) Å), terdentate facial Tp*, and monodentate/bidentate O/S/Se-donor ligands. The sulfido-W(V) complexes are characterized by lower energy electronic transitions, smaller giso, and larger Aiso(183W) values, and more positive reduction potentials compared with their oxo-W(V) counterparts. This series has been probed by sulfur K-edge X-ray absorption spectroscopy (XAS), the spectra being assigned by comparison to Tp*WOXY (X = Y = SPh; XY = tdt, qdt) and time-dependent density functional theoretical (TD-DFT) calculations. This study provides insight into the electronic nature and chemistry of the catalytically and biologically important sulfido-W unit.

14.
BMC Infect Dis ; 17(1): 751, 2017 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-29207945

RESUMO

BACKGROUND: We report the first adult case of Neisseria meningitidis W-135 presenting with meningococcal arthritis and myopericarditis concomitantly, without other classical features of meningococcal disease. CASE PRESENTATION: A 67-year-old Caucasian man presented with acute-onset polyarthralgia, myalgia, and fever. On examination he had polyarticular synovitis. An electrocardiogram (ECG) demonstrated ST-elevation in leads I, II, III, aVF, and V2-V6 without reciprocal depression, and a high-sensitivity troponin level was significantly elevated. Cardiac magnetic resonance (CMR) imaging on day five of admission demonstrated patchy pericardial enhancement. Neisseria meningitidis W-135 was isolated from both synovial fluid and blood cultures. The clinical outcome was favourable with intravenous ceftriaxone and myopericarditis treatment (colchicine and ibuprofen). CONCLUSIONS: We conclude that this is a rare case of disseminated Neisseria meningitidis W-135 presenting with acute polyarticular septic arthritis and myopericarditis, without other classical features of systemic meningococcal disease. The earlier described entity of primary meningococcal arthritis (PMA) can present in patients with meningococcal bacteraemia, and may not be distinct from disseminated meningococcal disease, but rather an atypical presentation of this.


Assuntos
Artrite Infecciosa/diagnóstico , Meningite Meningocócica/diagnóstico , Miocardite/diagnóstico , Idoso , Artrite Infecciosa/tratamento farmacológico , Artrite Infecciosa/microbiologia , Hemocultura , Ceftriaxona/uso terapêutico , Eletrocardiografia , Humanos , Imagem Cinética por Ressonância Magnética , Masculino , Meningite Meningocócica/tratamento farmacológico , Meningite Meningocócica/microbiologia , Miocardite/tratamento farmacológico , Miocardite/microbiologia , Neisseria meningitidis/isolamento & purificação , Líquido Sinovial/microbiologia
15.
J Chem Phys ; 147(2): 024904, 2017 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-28711045

RESUMO

Brownian Dynamics (BD) simulations are a standard tool for understanding the dynamics of polymers in and out of equilibrium. Quantitative comparison can be made to rheological measurements of dilute polymer solutions, as well as direct visual observations of fluorescently labeled DNA. The primary computational challenge with BD is the expensive calculation of hydrodynamic interactions (HI), which are necessary to capture physically realistic dynamics. The full HI calculation, performed via a Cholesky decomposition every time step, scales with the length of the polymer as O(N3). This limits the calculation to a few hundred simulated particles. A number of approximations in the literature can lower this scaling to O(N2 - N2.25), and explicit solvent methods scale as O(N); however both incur a significant constant per-time step computational cost. Despite this progress, there remains a need for new or alternative methods of calculating hydrodynamic interactions; large polymer chains or semidilute polymer solutions remain computationally expensive. In this paper, we introduce an alternative method for calculating approximate hydrodynamic interactions. Our method relies on an iterative scheme to establish self-consistency between a hydrodynamic matrix that is averaged over simulation and the hydrodynamic matrix used to run the simulation. Comparison to standard BD simulation and polymer theory results demonstrates that this method quantitatively captures both equilibrium and steady-state dynamics after only a few iterations. The use of an averaged hydrodynamic matrix allows the computationally expensive Brownian noise calculation to be performed infrequently, so that it is no longer the bottleneck of the simulation calculations. We also investigate limitations of this conformational averaging approach in ring polymers.

16.
Acta Pharmacol Sin ; 37(6): 814-24, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27133304

RESUMO

AIM: Jungermannenone A and B (JA, JB) are new ent-kaurane diterpenoids isolated from Chinese liverwort Jungermannia fauriana, which show anti-proliferation activities in cancer cells. In this study we investigated the mechanisms underlying the anticancer action of JA and JB in PC3 human prostate cancer cells in vitro. METHODS: A panel of 9 human cancer cell lines was tested. Cell proliferation was assessed with a real-time cell analyzer and MTT assay. Cell apoptosis, cell cycle distribution and ROS levels were measured using cytometry. Mitochondrial damage was examined by transmission electron microscopy. DNA damage was detected with comet assay. Apoptotic, DNA damage- and cell cycle-related proteins were analyzed using Western blotting. The expression of DNA repair genes was measured with qRT-PCR. RESULTS: Both JA and JB exerted potent anti-proliferative action against the 9 cancer cell lines, and PC3 cells were more sensitive with IC50 values of 1.34±0.09 and 4.93±0.20 µmol/L, respectively. JA (1.5 µmol/L) and JB (5 µmol/L) induced PC3 cell apoptosis, which was attenuated by the caspase inhibitor Z-VAD. Furthermore, both JA and JB caused mitochondrial damage and ROS accumulation in PC3 cells, whereas vitamin C blocked the ROS accumulation and attenuated the cytotoxicity of JA and JB. Moreover, both JA and JB induced DNA damage, accompanied by downregulated DNA repair proteins Ku70/Ku80 and RDA51. JA induced marked cell cycle arrest at the G0/G1 phase, which was related to c-Myc suppression, whereas JB enforced the cell cycle blockade in the G2/M phase, which associated with activation of the JNK signaling. CONCLUSION: Both JA and JB induce prostate cancer apoptosis via ROS accumulation and induction of cell cycle arrest.


Assuntos
Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Diterpenos do Tipo Caurano/química , Diterpenos do Tipo Caurano/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Linhagem Celular Tumoral , Hepatófitas/química , Humanos , Masculino , Próstata/efeitos dos fármacos , Próstata/metabolismo , Próstata/patologia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Espécies Reativas de Oxigênio/metabolismo
17.
Pharm Biol ; 54(2): 364-74, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26017567

RESUMO

CONTEXT: Bisbibenzyl compounds have gained our interests for their potential antitumor activity in malignant cell-types. OBJECTIVE: The objective of this study is to investigate the effect of bisbibenzyl compounds riccardin C (RC), marchantin M (MM), and riccardin D (RD) on androgen receptor (AR) in prostate cancer (PCa) cells. MATERIALS AND METHODS: After exposure to 10 µM of the compounds for 24 h, cell cycle and cell survival analyses were performed using FACS and MTT assay to confirm the effect of these bisbibenzyls on PCa LNCaP cells. Changes in the AR expression and function, as the result of exposure to the compounds, were investigated using real-time PCR, ELISA, transient transfection, western blotting (WB), immunoprecipitation, and immunofluorescence staining (IF). Chemical-induced autophagy was examined by WB, IF, and RNAi. RESULTS: RC, MM, and RD reduced the viability of LNCaP cells accompanied with arrested cell cycle in the G0/G1 phase and induction of apoptosis. Further investigation revealed that these compounds significantly inhibited AR expression at mRNA and protein levels, leading to the suppression of AR transcriptional activity. Moreover, inhibition of proteasome activity by bisbibenzyls, which in turn caused the induction of autophagy, as noted by induction of LC3B expression, conversion, and accumulation of punctate dots in treated cells. Co-localization of AR/LC3B and AR/Ub suggested that autophagy contributed to the degradation of polyubiquitinated-AR when proteasome activity was suppressed by the bisbibenzyls. DISCUSSION AND CONCLUSION: Suppression of proteasome activity and induction of autophagy were involved in bisbibenzyl-mediated modulation of AR activities and apoptosis, suggesting their potential in treating PCa.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Autofagia/efeitos dos fármacos , Bibenzilas/farmacologia , Neoplasias da Próstata , Inibidores de Proteassoma/farmacologia , Receptores Androgênicos/genética , Transcrição Gênica/efeitos dos fármacos , Antineoplásicos Fitogênicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Bibenzilas/isolamento & purificação , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Éteres Cíclicos/isolamento & purificação , Éteres Cíclicos/farmacologia , Expressão Gênica/efeitos dos fármacos , Hepatófitas/química , Humanos , Masculino , Éteres Fenílicos/isolamento & purificação , Éteres Fenílicos/farmacologia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Inibidores de Proteassoma/isolamento & purificação , Transporte Proteico/efeitos dos fármacos , Receptores Androgênicos/metabolismo , Estilbenos/isolamento & purificação , Estilbenos/farmacologia
18.
Inorg Chem ; 54(13): 6386-96, 2015 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-26046577

RESUMO

Reaction of Tp(iPr)Mo(VI)OS(OAr) with cobaltocene in toluene results in the precipitation of brown, microcrystalline oxosulfido-Mo(V) compounds, [CoCp2][Tp(iPr)Mo(V)OS(OAr)] (Cp(-) = η(5)-C5H5(-), Tp(iPr)(-) = hydrotris(3-isopropylpyrazol-1-yl)borate, OAr(-) = phenolate or 2-(s)Bu, 2-(t)Bu, 3-(t)Bu, 4-(s)Bu, 4-Ph, 3,5-(s)Bu2, 2-CO2Me, 2-CO2Et or 2-CO2Ph derivative thereof). The compounds are air- and water-sensitive and display ν(Mo═O) and ν(Mo[Formula: see text]S) IR absorption bands at ca. 890 and 435 cm(-1), respectively, 20-40 cm(-1) lower in energy than the corresponding bands in Tp(iPr)MoOS(OAr). They are electrochemically active and exhibit three reversible cyclovoltammetric waves (E(Mo(VI)/Mo(V)) = -0.40 to -0.66 V, E([CoCp2](+)/CoCp2) = -0.94 V and E(CoCp2/[CoCp2](-)) = -1.88 V vs SCE). Structural characterization of [CoCp2][Tp(iPr)MoOS(OC6H4CO2Et-2)]·2CH2Cl2 revealed a distorted octahedral Mo(V) anion with Mo═O and Mo[Formula: see text]S distances of 1.761(5) and 2.215(2) Å, respectively, longer than corresponding distances in related Tp(iPr)MoOS(OAr) compounds. The observation of strong S(1s) → (S(3p) + Mo(4d)) S K-preedge transitions indicative of a d(1) sulfido-Mo(V) moiety and the presence of short Mo═O (ca. 1.72 Å) and Mo[Formula: see text]S (ca. 2.25 Å) backscattering contributions in the Mo K-edge EXAFS further support the oxosulfido-Mo(V) formulation. The compounds are EPR-active, exhibiting highly anisotropic (Δg 0.124-0.150), rhombic, frozen-glass spectra with g1 close to the value observed for the free electron (ge = 2.0023). Spectroscopic studies are consistent with the presence of a highly covalent Mo[Formula: see text]S π* singly occupied molecular orbital. The compounds are highly reactive, with reactions localized at the terminal sulfido ligand. For example, the compounds react with cyanide and PPh3 to produce thiocyanate and SPPh3, respectively, and various (depending on solvent) oxo-Mo(V) species. Reactions with copper reagents also generally lead to desulfurization and the formation of oxo-Mo(V) or -Mo(IV) complexes.


Assuntos
Molibdênio/química , Compostos Organometálicos/química , Compostos Organometálicos/isolamento & purificação , Sulfetos/química , Sulfetos/isolamento & purificação , Cristalografia por Raios X , Modelos Moleculares , Espectroscopia por Absorção de Raios X
19.
Int J Clin Pract ; 74(3): e13486, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32100457
20.
BMC Cancer ; 14: 276, 2014 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-24755270

RESUMO

BACKGROUND: E2F1 transcription factor plays a vital role in the regulation of diverse cellular processes including cell proliferation, apoptosis, invasion and metastasis. E2F1 overexpression has been demonstrated in small cell lung cancer (SCLC), and extensive metastasis in early phase is the most important feature of SCLC. In this study, we investigated the involvement of E2F1 in the process of invasion and metastasis in SCLC by regulating the expression of matrix metalloproteinases (MMPs). METHODS: Immunohistochemistry was performed to evaluate the expression of E2F1 and MMPs in SCLC samples in a Chinese Han population. The impact of E2F1 on invasion and metastasis was observed by transwell and wound healing experiments with depletion of E2F1 by specific siRNA. The target genes regulated by E2F1 were identified by chromatin immunoprecipitation (ChIP)-to-sequence, and the expressions of target genes were detected by real time PCR and western blotting. The dual luciferase reporter system was performed to analyze the regulatory relationship between E2F1 and MMPs. RESULTS: E2F1 is an independent and adverse prognosis factor that is highly expressed in SCLC in a Chinese Han population. Knockdown of E2F1 by specific siRNA resulted in the downregulation of migration and invasion in SCLC. The expressions of MMP-9 and -16 in SCLC were higher than other MMPs, and their expressions were most significantly reduced after silencing E2F1. ChIP-to-sequence and promoter-based luciferase analysis demonstrated that E2F1 directly controlled MMP-16 expression via an E2F1 binding motif in the promoter. Although one E2F1 binding site was predicted in the MMP-9 promoter, luciferase analysis indicated that this binding site was not functionally required. Further study demonstrated that E2F1 transcriptionally controlled the expression of Sp1 and p65, which in turn enhanced the MMP-9 promoter activity in SCLC cells. The associations between E2F1, Sp1, p65, and MMP-9 were validated by immunohistochemistry staining in SCLC tumors. CONCLUSIONS: E2F1 acts as a transcriptional activator for MMPs and directly enhances MMP transcription by binding to E2F1 binding sequences in the promoter, or indirectly activates MMPs through enhanced Sp1 and NF-kappa B as a consequence of E2F1 activation in SCLC.


Assuntos
Fator de Transcrição E2F1/genética , Metaloproteinase 16 da Matriz/biossíntese , Metaloproteinase 9 da Matriz/biossíntese , Proteínas Quinases/metabolismo , Carcinoma de Pequenas Células do Pulmão/genética , Fator de Transcrição RelA/metabolismo , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Proliferação de Células , Fator de Transcrição E2F1/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Metástase Neoplásica/genética , Proteínas Quinases/genética , RNA Interferente Pequeno , Carcinoma de Pequenas Células do Pulmão/patologia , Fator de Transcrição RelA/genética
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