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1.
BMC Surg ; 24(1): 312, 2024 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-39407237

RESUMO

INTRODUCTION: To mitigate gastroparesis as well as other post-operative complications, we undertook a prospective multicenter study to assess the feasibility, safety, and efficacy in the short-term outcomes of laparoscopic and thoracoscopic whole stomach esophagectomy with preoperative pyloric balloon dilatation. METHODS: A prospective descriptive study on 37 patients with laparoscopic and thoracoscopic whole stomach esophagectomy with preoperative pyloric balloon dilatation from January 2019 to March 2023. The perioperative indications, clinical data, intra-operative index, pathological postoperative specimens, postoperative complications, and follow-up results were retrospectively evaluated. RESULTS: In our study, all patients were male, with dysphagia as the predominant symptom (45.9%). Esophageal cancer incidence was similar between middle and lower thirds. Nodules were the primary finding on esophagoscopy (48.6%). Preoperative pyloric dilation averaged 31.2 min without complications. Surgical duration ranged from 225 to 400 min (mean 305). Gastric tube fluid volume averaged 148.9 ± 110.66 ml per day. Among 34 post-operative cases underwent gastric transit scans, most had non-dilated stomachs with efficient pyloric drug circulation. Three cases required prolonged ventilation, precluding pyloric circulation scans. Four patients developed chylous fistula, one requiring chest tube embolization. Recurrent laryngeal nerve damage occurred in 10.8% of cases. CONCLUSION: After evaluating esophageal cancer patients undergoing laparoscopic whole-stomach esophagectomy with preoperative pyloric balloon dilatation, it was found that this procedure is safe, effective, and significantly reduces postoperative gastroparesis and related complications.


Assuntos
Neoplasias Esofágicas , Esofagectomia , Laparoscopia , Complicações Pós-Operatórias , Cuidados Pré-Operatórios , Toracoscopia , Humanos , Masculino , Esofagectomia/métodos , Neoplasias Esofágicas/cirurgia , Pessoa de Meia-Idade , Estudos Prospectivos , Laparoscopia/métodos , Toracoscopia/métodos , Idoso , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/etiologia , Cuidados Pré-Operatórios/métodos , Resultado do Tratamento , Dilatação/métodos , Piloro/cirurgia , Estudos de Viabilidade , Adulto , Gastroparesia/etiologia , Gastroparesia/prevenção & controle , Feminino
2.
J Am Chem Soc ; 144(26): 11608-11619, 2022 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-35700317

RESUMO

NMR spectroscopy is a powerful tool to investigate molecular structure and dynamics. The poor sensitivity of this technique, however, limits its ability to tackle questions requiring dilute samples. Low-concentration photochemically induced dynamic nuclear polarization (LC-photo-CIDNP) is an optically enhanced NMR technology capable of addressing the above challenge by increasing the detection limit of aromatic amino acids in solution up to 1000-fold, either in isolation or within proteins. Here, we show that the absence of NMR-active nuclei close to a magnetically active site of interest (e.g., the structurally diagnostic 1Hα-13Cα pair of amino acids) is expected to significantly increase LC-photo-CIDNP hyperpolarization. Then, we exploit the spin-diluted tryptophan isotopolog Trp-α-13C-ß,ß,2,4,5,6,7-d7 and take advantage of the above prediction to experimentally achieve a ca 4-fold enhancement in NMR sensitivity over regular LC-photo-CIDNP. This advance enables the rapid (within seconds) detection of 20 nM concentrations or the molecule of interest, corresponding to a remarkable 3 ng detection limit. Finally, the above Trp isotopolog is amenable to incorporation within proteins and is readily detectable at a 1 µM concentration in complex cell-like media, including Escherichia coli cell-free extracts.


Assuntos
Proteínas , Triptofano , Aminoácidos , Marcação por Isótopo , Espectroscopia de Ressonância Magnética/métodos , Triptofano/química
3.
BMC Med Inform Decis Mak ; 20(1): 108, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32546157

RESUMO

BACKGROUND: Predictive patient stratification is greatly emerging, because it allows us to prospectively identify which patients will benefit from what interventions before their condition worsens. In the biomedical research, a number of stratification methods have been successfully applied and have assisted treatment process. Because of heterogeneity and complexity of medical data, it is very challenging to integrate them and make use of them in practical clinic. There are two major challenges of data integration. Firstly, since the biomedical data has a high number of dimensions, combining multiple data leads to the hard problem of vast dimensional space handling. The computation is enormously complex and time-consuming. Secondly, the disparity of different data types causes another critical problem in machine learning for biomedical data. It has a great need to develop an efficient machine learning framework to handle the challenges. METHODS: In this paper, we propose a fast-multiple kernel learning framework, referred to as fMKL-DR, that optimise equations to calculate matrix chain multiplication and reduce dimensions in data space. We applied our framework to two case studies, Alzheimer's disease (AD) patient stratification and cancer patient stratification. We performed several comparative evaluations on various biomedical datasets. RESULTS: In the case study of AD patients, we enhanced significantly the multiple-ROIs approach based on MRI image data. The method could successfully classify not only AD patients and non-AD patients but also different phases of AD patients with AUC close to 1. In the case study of cancer patients, the framework was applied to six types of cancers, i.e., glioblastoma multiforme cancer, ovarian cancer, lung cancer, breast cancer, kidney cancer, and liver cancer. We efficiently integrated gene expression, miRNA expression, and DNA methylation. The results showed that the classification model basing on integrated datasets was much more accurate than classification model basing on the single data type. CONCLUSIONS: The results demonstrated that the fMKL-DR remarkably improves computational cost and accuracy for both AD patient and cancer patient stratification. We optimised the data integration, dimension reduction, and kernel fusion. Our framework has great potential for mining large-scale cohort data and aiding personalised prevention.


Assuntos
Doença de Alzheimer , Aprendizado de Máquina , Doença de Alzheimer/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Neoplasias/diagnóstico por imagem
4.
Nucleic Acids Res ; 45(16): 9481-9502, 2017 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-28934495

RESUMO

Developmentally programmed genome rearrangement accompanies differentiation of the silent germline micronucleus into the transcriptionally active somatic macronucleus in the ciliated protozoan Tetrahymena thermophila. Internal eliminated sequences (IES) are excised, followed by rejoining of MAC-destined sequences, while fragmentation occurs at conserved chromosome breakage sequences, generating macronuclear chromosomes. Some macronuclear chromosomes, referred to as non-maintained chromosomes (NMC), are lost soon after differentiation. Large NMC contain genes implicated in development-specific roles. One such gene encodes the domesticated piggyBac transposase TPB6, required for heterochromatin-dependent precise excision of IES residing within exons of functionally important genes. These conserved exonic IES determine alternative transcription products in the developing macronucleus; some even contain free-standing genes. Examples of precise loss of some exonic IES in the micronucleus and retention of others in the macronucleus of related species suggest an evolutionary analogy to introns. Our results reveal that germline-limited sequences can encode genes with specific expression patterns and development-related functions, which may be a recurring theme in eukaryotic organisms experiencing programmed genome rearrangement during germline to soma differentiation.


Assuntos
Proteínas de Protozoários/metabolismo , Tetrahymena thermophila/genética , Transposases/metabolismo , Cromossomos/genética , Éxons , Rearranjo Gênico , Heterocromatina/genética , Sequências Repetidas Invertidas , Macronúcleo/genética , Micronúcleo Germinativo , Proteínas de Protozoários/genética , Interferência de RNA , Transposases/genética
5.
Phys Rev Lett ; 115(10): 107003, 2015 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-26382698

RESUMO

Density functional plus dynamical mean field calculations are used to show that in transition metal oxides, rotational and tilting (GdFeO(3)-type) distortions of the ideal cubic perovskite structure produce a multiplicity of low-energy optical transitions which affect the conductivity down to frequencies of the order of 1 or 2 mV (terahertz regime), mimicking non-Fermi-liquid effects even in systems with a strictly Fermi-liquid self-energy. For CaRuO(3), a material whose measured electromagnetic response in the terahertz frequency regime has been interpreted as evidence for non-Fermi-liquid physics, the combination of these band structure effects and a renormalized Fermi-liquid self-energy accounts for the low frequency optical response which had previously been regarded as a signature of exotic physics. Signatures of deviations from Fermi-liquid behavior at higher frequencies (∼100 meV) are discussed.

6.
Org Biomol Chem ; 12(12): 1942-56, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24531242

RESUMO

Developing new compounds targeting virulence factors (e.g., inhibition of pilus assembly by pilicides) is a promising approach to combating bacterial infection. A high-throughput screening campaign of a library of 17 500 small molecules identified 2-amino-3-acyl-tetrahydrobenzothiophene derivatives (hits 2 and 3) as novel inhibitors of pili-dependent biofilm formation in a uropathogenic Escherichia coli strain UTI89. Based on compounds 2 and 3 as the starting point, we designed and synthesized a series of structurally related analogs and investigated their activity against biofilm formation of E. coli UTI89. Systematic structural modification of the initial hits provided valuable information on their SARs for further optimization. In addition, small structural changes to the parent molecules resulted in low micromolar inhibitors (20-23) of E. coli biofilm development without an effect on bacterial growth. The hit compound 3 and its analog 20 were confirmed to prevent pili formation in a hemagglutination (HA) titer assay and electron microscopy (EM) measurements. These findings suggest that 2-amino-3-acyl-tetrahydrobenzothiophenes may serve as a new class of compounds for further elaboration as antibacterial agents with antivirulence activity.


Assuntos
Anilidas/farmacologia , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Tiofenos/farmacologia , Fatores de Virulência/antagonistas & inibidores , Anilidas/síntese química , Anilidas/química , Antibacterianos/síntese química , Antibacterianos/química , Biofilmes/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Triagem em Larga Escala , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade , Tiofenos/síntese química , Tiofenos/química
7.
Pediatr Neurol ; 155: 177-181, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38669800

RESUMO

BACKGROUND: Despite extensive research on Guillain-Barré syndrome (GBS) in adults and children, there is a lack of comparison regarding short-term outcomes in various age groups. Our study aims to elucidate the differences in clinical features and short-term outcomes in Vietnam. METHODS: After retrospective data collection, we compared clinical features in patients with GBS aged ≤16 years at Children's Hospital 2 and aged >16 years at University Medical Center Ho Chi Minh City from 2017 to 2021. A positive short-term outcome was recorded if patients had a GBS Disability Score of 0 to 2 at hospital discharge. RESULTS: We analyzed 109 adults (58.7% males; mean age 50.6 ± 17.7) and 111 children (58.6% males; mean age 7.2 ± 4.9). Comparable antecedent infection and immunization incidence in both groups were observed (35.8% vs 45.9%, P > 0.05). Pain and sensory disturbance were the most common onset symptom in adults (57.8%), whereas lower limb weakness predominated in children (61.3%). Ophthalmoplegia (18.3% vs 5.4%), pain, sensory disturbance (85.3% vs 67.6%), ataxia (33.0% vs 15.3%) were more prevalent in adults (P < 0.05). The axonal subtype was prominent in both adults (51.4%) and children (53.2%). Patients were classified into: classic GBS (49.5% and 68.5%), GBS variants (11.0% and 15.3%), classic Miller Fisher syndrome (MFS) (1.8% and 1.8%), MFS variants (2.8% and 0%), and GBS/MFS overlap (34.9% and 14.4%). Short-term outcomes did not significantly differ based on age. CONCLUSIONS: Age-related variations in clinical features were observed, but adults and children exhibited similar short-term functional outcomes.


Assuntos
Síndrome de Guillain-Barré , Humanos , Síndrome de Guillain-Barré/epidemiologia , Síndrome de Guillain-Barré/fisiopatologia , Síndrome de Guillain-Barré/diagnóstico , Vietnã/epidemiologia , Masculino , Feminino , Estudos Retrospectivos , Criança , Adulto , Pessoa de Meia-Idade , Adolescente , Pré-Escolar , Adulto Jovem , Idoso , Fatores Etários
8.
Ann Med Surg (Lond) ; 86(1): 580-587, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38222770

RESUMO

Introduction: Mesenchymal chondrosarcoma (MC) is a rapidly progressive sarcoma that predominantly impacts the bones. Making up only 3% of chondrosarcomas, about one-third of these tumours develop in extra-skeletal sites. Case presentation: The authors present a clinical case of a 42-year-old patient who was diagnosed with MC 8 years ago, now admitted to the hospital with a palpable epigastric mass. Clinical and laboratory examinations showed consistent results for MC tumours, with metastasis to the body and tail of the pancreas and invasion of the splenic vein. Surgical resection and systemic screening were performed to ensure that there were no lesions elsewhere. Regular follow-up has found no localized lesions or complications after 15 months. Clinical discussion: Metastatic extra-skeletal mesenchymal chondrosarcoma of the pancreas is exceptionally rare. To our current understanding, only 14 such cases have been documented in medical literature. The symptoms of pancreatic metastasis are diverse and the radiographic features of metastatic mesenchymal chondrosarcoma are not typically distinct. Conclusions: Although MC tumours do not frequently occur in sites other than the axial system, a tumour presenting later in a patient with a history of MC should be reviewed to confirm the diagnosis of metastatic MC. Treatment can vary between surgery, radiation therapy and systemic therapy.

9.
World J Pediatr Congenit Heart Surg ; 15(3): 287-297, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38263638

RESUMO

BACKGROUND: This article aims to demonstrate the morphology of 261 total anomalous pulmonary venous connection (TAPVC) cases operated at Children's Hospital 1 with in-hospital mortality of 19.5% (51/261). METHODS: All the surgical protocols of TAPVC cases repaired between 2008 and June 2023 were reviewed. The descriptions of TAPVC were based on operative findings by surgeons. RESULTS: A total of 261 TAPVC patients were operated, including 124 (47.5%) supra, 83 (31.8%) intra, 41 (15.7%) infra, and 13 (5%) mixed cases. The in-hospital mortality was 19.5% (51/261). Fifteen cases are associated with other anomalies of the heart. Four subtypes of 124 supra TAPVC were found, with 42 (33.9%) obstructed cases. The standard was all pulmonary veins (PVs) forming a common vein (CV) and draining into the innominate veins, then going to the superior vena cava (SVC) (100/124, 80.6%). Eleven supra TAPVC cases were vascular vise type. Ten cases had the vertical vein running from the right of the CV and draining directly into the SVC. Of 83 intracardiac TAPVCs with 9 (10.8%) obstructed cases, the most common was all PVs draining directly into the coronary sinus (60/83, 72.3%). The second was all PVs draining directly into the right atrium (RA) via separated ostia or forming a CV before entering the RA (17/83, 20.5%). Also, there were three cases with rare variants and 100% obstruction when the diagnosis was explored. The in-hospital mortality of intracardiac type was 13.3% (11/83) 41 infra TAPVC with obstructed rate of 61% (25/41) and in-hospital mortality of 29.3% (12/41). Thirteen mixed TAPVCs were repaired, with most cases having three PVs forming a CV. CONCLUSION: This article provides valuable information about the morphology of TAPVC types in Asian patients.


Assuntos
Mortalidade Hospitalar , Veias Pulmonares , Síndrome de Cimitarra , Humanos , Feminino , Masculino , Síndrome de Cimitarra/cirurgia , Síndrome de Cimitarra/mortalidade , Vietnã/epidemiologia , Estudos Retrospectivos , Veias Pulmonares/anormalidades , Veias Pulmonares/cirurgia , Lactente , Recém-Nascido , Pré-Escolar , Procedimentos Cirúrgicos Cardíacos/métodos , Criança
10.
Bioorg Chem ; 49: 24-32, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23856367

RESUMO

Endocannabinoids appear to be involved in a variety of physiological processes. Lipoxygenase activity has been known to be affected by unsaturated fatty acids or phenolic compounds. In this study, we examined whether endocannabinoids containing both N-acyl group and phenolic group can affect the activity of soybean lipoxygenase (LOX)-1, similar to mammalian 15-lipoxygenase in physicochemical properties. First, N-arachidonoyl dopamine and N-oleoyl dopamine were found to inhibit soybean LOX-1-catalyzed oxygenation of linoleic acid in a non-competitive manner with a Ki value of 3.7 µM and 6.2 µM, respectively. Meanwhile, other endocannabinoids failed to show a remarkable inhibition of soybean LOX-1. Separately, N-arachidonoyl dopamine and N-arachidonoyl serotonin were observed to inactivate soybean LOX-1 with Kin value of 27 µM and 24 µM, respectively, and k3 value of 0.12 min(-1) and 0.35 min(-1), respectively. Furthermore, such an inactivation was enhanced by ascorbic acid, but suppressed by 13(S)-hydroperoxy-9,11-octadecadienoic acid. Taken together, it is proposed that endocannabinoids containing polyunsaturated acyl moiety and phenolic group may be efficient for the inhibition as well as inactivation of 15-lipoxygenase.


Assuntos
Endocanabinoides/farmacologia , Inibidores Enzimáticos/farmacologia , Glycine max/enzimologia , Lipoxigenase/metabolismo , Biocatálise/efeitos dos fármacos , Relação Dose-Resposta a Droga , Endocanabinoides/química , Inibidores Enzimáticos/química , Estrutura Molecular , Relação Estrutura-Atividade
11.
Chem Pharm Bull (Tokyo) ; 61(10): 1002-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24088692

RESUMO

Jasmonates are lipid-based stress hormones that are critical for the defense of plants against insects. Two naturally occurring jasmonates, jasmonic acid and methyl jasmonate, have recently been explored for their efficacy as anti-cancer agents. Furthermore, certain synthetic jasmonates (e.g., the cyclopentenone isoprostane J2) exert anti-inflammatory actions in lipopolysaccharide (LPS)-challenged murine macrophages via down-regulation of chemokines and other inflammatory mediators. Chemokines participate in the development and progression of many inflammatory disorders, such as atopic dermatitis (AD) and Crohn's disease, as exemplified by the role of macrophage-derived chemokine (MDC/CCL22) in the pathology of AD. The current study therefore investigated the impact of jasmonate derivatives (jasmonic acid and methyl jasmonate) and their synthetic analogues (J2 and J7) on the expression of MDC in interferon (IFN)-γ- and tumor necrosis factor (TNF)-α-stimulated HaCaT human keratinocytes, as well as the attendant mechanism of action. Jasmonic acid, methyl jasmonate, and J2 failed to inhibit the cytokine-stimulated production of MDC. By contrast, J7 suppressed the mRNA and protein expression levels of MDC in a dose-dependent manner. Moreover, J7 diminished the activation of signal transducers and activators of transcription 1 (STAT1), but had no inhibitory effect on the nuclear factor kappa B (NF-κB) or mitogen-activated protein kinase (MAPK) pathways. These results demonstrate that J7 impairs IFN-γ- and TNF-α-induced inflammatory chemokine production by targeting the STAT1 pathway.


Assuntos
Anti-Inflamatórios/farmacologia , Antineoplásicos/toxicidade , Quimiocinas/metabolismo , Ciclopentanos/química , Ciclopentanos/farmacologia , Regulação para Baixo/efeitos dos fármacos , Ácidos Graxos Insaturados/química , Oxilipinas/farmacologia , Fator de Transcrição STAT1/metabolismo , Animais , Anti-Inflamatórios/química , Antineoplásicos/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Quimiocinas/genética , Ácidos Graxos Insaturados/farmacologia , Humanos , Mediadores da Inflamação/metabolismo , Interferon gama/farmacologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Lipopolissacarídeos/toxicidade , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Oxilipinas/química , RNA Mensageiro/metabolismo , Fator de Transcrição STAT1/agonistas , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia
12.
Polymers (Basel) ; 15(5)2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36904320

RESUMO

Injection molding has become an increasingly widely used method in the production of plastic parts. The injection process can be separated into five steps: mold closure, filling, packing, cooling, and product ejection. Before the melted plastic is loaded into the mold, the mold needs to be raised to a specified temperature, in order to increase the mold's filling capacity and improve the resultant product quality. One of the easy methods used to control a mold's temperature is to provide hot water through a cooling channel in the mold, to raise the temperature. In addition, this channel can be used for cooling the mold with cool fluid. This is simple, effective, and cost efficient, involving uncomplicated products. To improve the heating effectiveness of the hot water, a conformal cooling-channel design is considered in this paper. Through heat-transfer simulation using the CFX module in the Ansys software, an optimal cooling channel was defined according to the simulation result, using the Taguchi method integrated with principal component analysis. The comparison of traditional vs. conformal cooling channels revealed higher temperature rises in the first 100 s in both molds. During heating, conformal cooling produced higher temperatures compared with traditional cooling. Conformal cooling demonstrated better performance, with average temperature peaking at 58.78 °C and a range of 63.4 °C (max) to 54.66 °C (min). Traditional cooling resulted in an average steady-state temperature of 56.63 °C and a range of 61.74 °C (max) to 53.18 °C (min). Finally, the simulation results were verified experimentally.

13.
Microorganisms ; 11(2)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36838456

RESUMO

Locus-specific gene amplification and genome-wide endoreplication generate the elevated copy number of ribosomal DNA (rDNA, 9000 C) and non-rDNA (90 C) chromosomes in the developing macronucleus of Tetrahymena thermophila. Subsequently, all macronuclear chromosomes replicate once per cell cycle during vegetative growth. Here, we describe an unanticipated, programmed switch in the regulation of replication initiation in the rDNA minichromosome. Early in development, the 21 kb rDNA minichromosome is preferentially amplified from 2 C to ~800 C from well-defined origins, concurrent with genome-wide endoreplication (2 C to 8-16 C) in starved mating Tetrahymena (endoreplication (ER) Phase 1). Upon refeeding, rDNA and non-rDNA chromosomes achieve their final copy number through resumption of just the endoreplication program (ER Phase 2). Unconventional rDNA replication intermediates are generated primarily during ER phase 2, consistent with delocalized replication initiation and possible formation of persistent RNA-DNA hybrids. Origin usage and replication fork elongation are affected in non-rDNA chromosomes as well. Despite the developmentally programmed 10-fold reduction in the ubiquitous eukaryotic initiator, the Origin Recognition Complex (ORC), active initiation sites are more closely spaced in ER phases 1 and 2 compared to vegetative growing cells. We propose that initiation site selection is relaxed in endoreplicating macronuclear chromosomes and may be less dependent on ORC.

14.
J Biol Chem ; 286(37): 32424-35, 2011 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-21799014

RESUMO

Accurate DNA replication requires a complex interplay of many regulatory proteins at replication origins. The CMG (Cdc45·Mcm2-7·GINS) complex, which is composed of Cdc45, Mcm2-7, and the GINS (Go-Ichi-Ni-San) complex consisting of Sld5 and Psf1 to Psf3, is recruited by Cdc6 and Cdt1 onto origins bound by the heterohexameric origin recognition complex (ORC) and functions as a replicative helicase. Trypanosoma brucei, an early branched microbial eukaryote, appears to express an archaea-like ORC consisting of a single Orc1/Cdc6-like protein. However, unlike archaea, trypanosomes possess components of the eukaryote-like CMG complex, but whether they form an active helicase complex, associate with the ORC, and regulate DNA replication remains unknown. Here, we demonstrated that the CMG complex is formed in vivo in trypanosomes and that Mcm2-7 helicase activity is activated by the association with Cdc45 and the GINS complex in vitro. Mcm2-7 and GINS proteins are confined to the nucleus throughout the cell cycle, whereas Cdc45 is exported out of the nucleus after DNA replication, indicating that nuclear exclusion of Cdc45 constitutes one mechanism for preventing DNA re-replication in trypanosomes. With the exception of Mcm4, Mcm6, and Psf1, knockdown of individual CMG genes inhibits DNA replication and cell proliferation. Finally, we identified a novel Orc1-like protein, Orc1b, as an additional component of the ORC and showed that both Orc1b and Orc1/Cdc6 associate with Mcm2-7 via interactions with Mcm3. All together, we identified the Cdc45·Mcm2-7·GINS complex as the replicative helicase that interacts with two Orc1-like proteins in the unusual origin recognition complex in trypanosomes.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Núcleo Celular/metabolismo , Replicação do DNA/fisiologia , DNA de Protozoário/biossíntese , Complexo de Reconhecimento de Origem/metabolismo , Proteínas de Protozoários/metabolismo , Trypanosoma brucei brucei/metabolismo , Proteínas de Ciclo Celular/genética , Núcleo Celular/genética , DNA de Protozoário/genética , Técnicas de Silenciamento de Genes , Complexo de Reconhecimento de Origem/genética , Proteínas de Protozoários/genética , Trypanosoma brucei brucei/genética
15.
Bioorg Med Chem Lett ; 22(9): 3126-9, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22483395

RESUMO

Four new cytochalasin derivatives (1-4), together with cytochalasin B (5), were isolated from the fungus Phoma sp. obtained from the giant jellyfish Nemopilema nomurai. The planar structure and relative stereochemistry were established by analysis of 1D and 2D NMR data. The absolute configuration was defined by the modified Mosher's method. The compounds showed significant cytotoxicity against a small panel of human solid tumor cell lines (A549, SK-OV-3, SK-MEL-2, XF 498, and HCT15) with IC(50) values in the range of 0.5-30 µM. The cytochalasin B (5) showed obvious cytotoxicity with IC(50) of 7.9 µM against HeLa human cervical carcinoma cells.


Assuntos
Ascomicetos/química , Citocalasinas/farmacologia , Cifozoários/microbiologia , Animais , Antineoplásicos/química , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Citocalasinas/química , Relação Dose-Resposta a Droga , Detecção Precoce de Câncer , Humanos , Concentração Inibidora 50 , Estrutura Molecular
16.
Bioorg Med Chem ; 20(13): 4109-16, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22633122

RESUMO

A chlorinated methyl jasmonate analog (J7) was elaborated as an in vitro anti-inflammatory lead. However, its in vitro efficacy profile was not reproduced in a subsequent in vivo evaluation, presumably due to its rapid enzymatic hydrolysis in a biological system. In an attempt to improve the metabolic stability of the lead J7 by replacement of its labile methyl ester with reasonable ester groups, several analogs resistant to enzymatic hydrolysis were synthesized. In vivo evaluation of the stability-improved analogs showed that these compounds displayed higher efficacy than the lead J7, suggesting that these new jasmonate analogs may serve as potential anti-inflammatory leads.


Assuntos
Anti-Inflamatórios/síntese química , Ciclopentanos/química , Ciclopentanos/síntese química , Ácidos Graxos Insaturados/síntese química , Oxilipinas/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Ciclopentanos/farmacologia , Ácidos Graxos Insaturados/química , Ácidos Graxos Insaturados/farmacologia , Camundongos , Óxido Nítrico/metabolismo , Oxilipinas/síntese química , Oxilipinas/farmacologia , Relação Estrutura-Atividade
17.
Ann Med Surg (Lond) ; 78: 103785, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35734662

RESUMO

Background: Biliary cystadenoma is a rare cystic neoplasm of the liver. The clinical signs and symptoms are nonspecific, and treatment strategy is variable. Case presentation: In this study, we presented a case of a 32-year-old female with multilocular biliary cystadenoma. The patient underwent partial removal of the hepatic cyst two times in two different hospitals for two years and that the histopathological results were biliary cystic adenoma but was successfully treated by radical resection after the second recurrence. The patient underwent a J-shaped laparotomy. The giant cystic mass measuring 20 cm × 15 cm was below the position of the right anterior segment. This lesion pushed the liver parenchyma to both sides and compressed the hepatic hilum, causing dilatation of the intrahepatic bile ducts. The patient underwent complete resection of cystic mass. During the dissection, a 0.5mm-diameter fistula of left hepatic duct with the cyst was found. It was sutured using absorbable polydioxanone (PDS 6.0) and the cystic duct tube (C tube) (6 Fr) was inserted via the cystic duct into the left hepatic duct due to drain the bile fluid. Discussion: A biliary cystadenoma (BCA) primary origin is occasionally rare. Although imaging modalities such as ultrasound, computed tomography and magnetic resonance imaging could be suggestive, however, the definitive diagnosis is depended on the histological examination. Despite of being a benign tumor, it has a high risk of recurrence after conservative treatment. The potential risk for malignant is also present. Therefore, complete resection of the tumors is the treatment of choice. Conclusion: We herein present a report of a rare case with had a giant biliary cystadenoma (BCA) primary origin. This report aims to improve the understanding of the diagnosis and management of this uncommon disease.

18.
Plant Mol Biol ; 77(6): 537-45, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22038093

RESUMO

Mini-chromosome maintenance (MCM) proteins form heterohexameric complex (MCM2-7) to serve as licensing factor for DNA replication to make sure that genomic DNA is replicated completely and accurately once during S phase in a single cell cycle. MCMs were initially identified in yeast for their role in plasmid replication or cell cycle progression. Each of six MCM contains highly conserved sequence called "MCM box", which contains two ATPase consensus Walker A and Walker B motifs. Studies on MCM proteins showed that (a) the replication origins are licensed by stable binding of MCM2-7 to form pre-RC (pre-replicative complex) during G1 phase of the cell cycle, (b) the activation of MCM proteins by CDKs (cyclin-dependent kinases) and DDKs (Dbf4-dependent kinases) and their helicase activity are important for pre-RC to initiate the DNA replication, and (c) the release of MCMs from chromatin renders the origins "unlicensed". DNA replication licensing in plant is, in general, less characterized. The MCMs have been reported from Arabidopsis, maize, tobacco, pea and rice, where they are found to be highly expressed in dividing tissues such as shoot apex and root tips, localized in nucleus and cytosol and play important role in DNA replication, megagametophyte and embryo development. The identification of six MCM coding genes from pea and Arabidopsis suggest six distinct classes of MCM protein in higher plant, and the conserved function right across the eukaryotes. This overview of MCMs contains an emphasis on MCMs from plants and the novel role of MCM6 in abiotic stress tolerance.


Assuntos
Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Ciclo Celular/fisiologia , Replicação do DNA/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ciclo Celular/genética , Replicação do DNA/genética
19.
Plant Mol Biol ; 76(1-2): 19-34, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21365356

RESUMO

The eukaryotic pre-replicative complex (Pre-RC), including heterohexameric minichromosome maintenance (MCM2-7) proteins, ensures that the DNA in genome is replicated only once per cell division cycle. The MCMs provide DNA unwinding function during the DNA replication. Since MCM proteins play essential role in cell division and most likely are affected during stress conditions therefore their overexpression in plants may help in stress tolerance. But the role of MCMs in abiotic stress tolerance in plants has not been reported so far. In this study we report that: a) the MCM6 transcript is upregulated in pea plant in response to high salinity and cold stress and not with ABA, drought and heat stress; b) MCM6 overexpression driven by a constitutive cauliflower mosaic virus-35S promoter in tobacco plants confers salinity tolerance. The T(1) transgenics plants were able to grow to maturity and set normal viable seeds under continuous salinity stress, without yield penalty. It was observed that in salt-grown T(1) transgenic plants the Na(+) ions is mostly accumulated in mature leaves and not in seeds of T(1) transgenic lines as compared with the wild-type (WT) plants. T(1) transgenic plants exhibited better growth status under salinity stress conditions in comparison to WT plants. Furthermore, the T(1) transgenic plants maintained significantly higher levels of leaf chlorophyll content, net photosynthetic rate and therefore higher dry matter accumulation and yield with 200 mM NaCl as compared to the WT plants. Tolerance index data showed better salt tolerance potential of T(1) transgenic plants in comparison to WT. These findings provide first direct evidence that overexpression of single subunit MCM6 confers salinity stress tolerance without yield loss. The possible mechanism of salinity tolerance is discussed. These findings suggest that DNA replication machinery can be exploited for promoting stress tolerance in crop plants.


Assuntos
Pisum sativum/crescimento & desenvolvimento , Pisum sativum/genética , Proteínas de Plantas/genética , Tolerância ao Sal/genética , Ácido Abscísico/farmacologia , Sequência de Aminoácidos , Temperatura Baixa , Secas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Temperatura Alta , Dados de Sequência Molecular , Filogenia , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/classificação , Plantas Geneticamente Modificadas , Subunidades Proteicas/classificação , Subunidades Proteicas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Plântula/genética , Plântula/crescimento & desenvolvimento , Homologia de Sequência de Aminoácidos , Cloreto de Sódio/farmacologia
20.
Bioorg Med Chem ; 19(4): 1520-7, 2011 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-21257314

RESUMO

A series of endogenous fatty acid amides and their analogues (1-78) were prepared, and their inhibitory effects on pro-inflammatory mediators (NO, IL-1ß, IL-6, and TNF-α) in LPS-activated RAW264.7 cells were evaluated. Their inhibitory activity on the pro-inflammatory chemokine MDC in IFN-γ-activated HaCaT cells was also examined. The results showed that the activity is strongly dependent on the nature of the fatty acid part of the molecules. As expected, the amides derived from enone fatty acids showed significant activity and were more active than those derived from other types of fatty acids. A variation of the amine headgroup also altered bioactivity profile remarkably, possibly by modulating cell permeability. Regarding the amine part of the molecules, N-acyl dopamines exhibited the most potent activity (IC(50) ∼2 µM). This is the first report of the inhibitory activity of endogenous fatty acid amides and their analogues on the production of nitric oxide, cytokines (IL-1ß, IL-6, and TNF-α) and the chemokine MDC. This study suggests that the enone fatty acid-derived amides (such as N-acyl ethanolamines and N-acyl amino acids) and N-acyl dopamines may be potential anti-inflammatory leads.


Assuntos
Amidas/química , Amidas/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Ácidos Graxos/química , Animais , Linhagem Celular , Humanos , Camundongos , Óxido Nítrico/biossíntese
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