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Cascade molecular events in complex systems are of vital importance for enhancing molecular diagnosis and information processing. However, the conversion of a cascaded biosensing system into a multilayer encrypted molecular keypad lock remains a significant challenge in the development of molecular logic devices. In this study, we present a photocleavable DNA nanotube-based dual-amplified resonance Rayleigh scattering (RRS) system for detecting microRNA-126 (miR-126). The cascading dual-amplification biosensing system provides a multilayer-encrypted prototype with the functionality of a molecular computing cascade keypad lock. RRS signals were greatly amplified by using photocleavable DNA nanotubes and enzyme-assisted strand displacement amplification (SDA). In the presence of miR-126, enzyme-assisted SDA produced numerous identical nucleotide fragments as the target, which were then specifically attached to magnetic beads through the DNA nanotube by using a Y-shaped DNA scaffold. Upon ultraviolet irradiation, the DNA nanotube was released into the solution, resulting in an increase in the intensity of the RRS signal. This strategy demonstrated a low limit of detection (0.16 fM) and a wide dynamic range (1 fM to 1 nM) for miR-126. Impressively, the enzyme-assisted SDA offers a molecular computing model for generating the target pool, which serves as the input element for unlocking the system. By cascading the molecular computing process, we successfully constructed a molecular keypad lock with a multilevel authentication technique. The proposed system holds great potential for applications in molecular diagnosis and information security, indicating significant value in integrating molecular circuits for intelligent sensing.
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Ranking among the most effective anticancer drugs, anthracyclines represent an important family of aromatic polyketides generated by type II polyketide synthases (PKSs). After formation of polyketide cores, the post-PKS tailoring modifications endow the scaffold with various structural diversities and biological activities. Here we demonstrate an unprecedented four-enzyme-participated hydroxyl regioisomerization process involved in the biosynthesis of kosinostatin. First, KstA15 and KstA16 function together to catalyze a cryptic hydroxylation of the 4-hydroxyl-anthraquinone core, yielding a 1,4-dihydroxyl product, which undergoes a chemically challenging asymmetric reduction-dearomatization subsequently acted by KstA11; then, KstA10 catalyzes a region-specific reduction concomitant with dehydration to afford the 1-hydroxyl anthraquinone. Remarkably, the shunt product identifications of both hydroxylation and reduction-dehydration reactions, the crystal structure of KstA11 with bound substrate and cofactor, and isotope incorporation experiments reveal mechanistic insights into the redox dearomatization and rearomatization steps. These findings provide a distinguished tailoring paradigm for type II PKS engineering.
Assuntos
Aminoglicosídeos/biossíntese , Antraciclinas/metabolismo , Proteínas de Bactérias/metabolismo , Enzimas/metabolismo , Aminoglicosídeos/química , Antraciclinas/química , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Biocatálise , Vias Biossintéticas , Enzimas/química , Enzimas/genética , Micromonospora/genética , Micromonospora/metabolismo , Modelos Moleculares , Estrutura Molecular , Mutação , Domínios Proteicos , EstereoisomerismoRESUMO
Recent research has indicated that Long noncoding RNAs (LncRNAs) are crucial in many disorders, especially tumors. However, the exact role of LncRNA XLOC_006786 (LncRNA-SPIDR-2:1) in malignancies, especially in human osteosarcoma, is unclear. The results of RTâqPCR, western blotting, CCK-8 assays, and Transwell assays showed that LncRNA XLOC_006786 inhibited osteosarcoma cell proliferation, invasion, and migration, indicating that it may be a tumor suppressor gene in osteosarcoma. We found that LncRNA XLOC_006786 negatively regulated NOTCH3, which is an oncogenic gene in osteosarcoma, as we previously reported. Bioinformatics analysis showed that miR-491-5p may be a direct target of LncRNA XLOC_006786, while NOTCH3 is a key target of miR-491-5p. Then, we verified that LncRNA XLOC_006786 could prevent lung metastatic osteosarcoma in vivo. Taken together, our research showed that LncRNA XLOC_006786 suppresses osteosarcoma proliferation, invasion, and metastasis through the NOTCH3 signaling pathway by targeting miR-491-5p.
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There are varying definitions of women at high risk of breast cancer across different institutions, and there are reports suggesting that the breast cancer risk assessment tools have not been well integrated into clinical practice. In this study, we tried to investigate the perceived importance of different breast cancer risk factors by physicians in China. A cross-sectional survey involving 386 anonymous physicians was conducted using a 20-item, 5-point Likert scale questionnaire. The Kruskal-Wallis test and post-hoc pairwise comparisons were used to compare the differences in response. Most of the respondents were either breast surgeons/specialists (n=161; 41.7%) or medical oncologists (n=151; 39.1%), and the results showed that the breast cancer risk factors were not perceived as equally important. The weighting of each risk factor also varied depending on the physician's medical specialty, location of practice, and the number of years of clinical experience. This study provides a more updated insight into the perceptions of physicians in China toward the breast cancer risk factors, as well as underlines the potential improvements in breast cancer risk assessment strategies that can be done.
Assuntos
Neoplasias da Mama , Detecção Precoce de Câncer/psicologia , Oncologistas/psicologia , Médicos/psicologia , Cirurgiões/psicologia , Adulto , Atitude do Pessoal de Saúde , China , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade , Padrões de Prática Médica/estatística & dados numéricos , Inquéritos e QuestionáriosRESUMO
In the screening of 11 E. coli strains overexpressing recombinant oxidoreductases from Bacillus sp. ECU0013, an NADPH-dependent aldo-keto reductase (YtbE) was identified with capability of producing chiral alcohols. The protein (YtbE) was overexpressed, purified to homogeneity, and characterized of biocatalytic properties. The purified enzyme exhibited the highest activity at 50°C and optimal pH at 6.5. YtbE served as a versatile reductase showing a broad substrate spectrum towards different aromatic ketones and keto esters. Furthermore, a variety of carbonyl substrates were asymmetrically reduced by the purified enzyme with an additionally coupled NADPH regeneration system. The reduction system exhibited excellent enantioselectivity (>99% ee) in the reduction of all the aromatic ketones and high to moderate enantioselectivity in the reduction of α- and ß-keto esters. Among the ketones tested, ethyl 4,4,4-trifluoroacetoacetate was found to be reduced to ethyl (R)-4,4,4-trifluoro-3-hydroxy butanoate, an important pharmaceutical intermediate, in excellent optical purity. To the best of our knowledge, this is the first report of ytbE gene-encoding recombinant aldo-keto reductase from Bacillus sp. used as biocatalyst for stereoselective reduction of carbonyl compounds. This study provides a useful guidance for further application of this enzyme in the asymmetric synthesis of chiral alcohol enantiomers.
Assuntos
Oxirredutases do Álcool/metabolismo , Bacillus/enzimologia , Oxirredutases do Álcool/química , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/isolamento & purificação , Aldeído Redutase , Aldo-Ceto Redutases , Bacillus/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Estabilidade Enzimática , Escherichia coli/genética , Expressão Gênica , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Análise de Sequência de DNA , Estereoisomerismo , Especificidade por Substrato , TemperaturaRESUMO
The interaction of a water-soluble cationic porphyrin, meso-tetrakis (4-N,N,N-trimethylanilinium) porphyrin (TMAP), with two proteins, bovine serum albumin (BSA) and human serum albumin (HSA), was studied by UV-vis absorption spectroscopy, fluorescence spectroscopy, fluorescence anisotropy and synchronous fluorescence spectroscopy at neutral aqueous solutions. Free base TMAP bound to proteins as monomers and no aggregation was observed. The binding of TMAP quenched the fluorescence of the protein. On the contrary, the fluorescence of TMAP was enhanced and the fluorescence anisotropy increased due to the binding. The direct static binding mechanism could account for the quenching by TMAP and the binding constants were calculated. TMAP showed a higher quenching efficiency and binding constant of HSA than BSA. The binding of TMAP had no obvious effect on the molecular conformation of the protein. There was only one binding site for TMAP and it was located on the surface of the protein molecule. Electrostatic force played an important role in the binding due to the opposite charges on porphyrin and the proteins.
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Porfirinas/metabolismo , Soroalbumina Bovina/metabolismo , Albumina Sérica/metabolismo , Análise Espectral/métodos , Água/química , Animais , Sítios de Ligação , Cátions/química , Bovinos , Polarização de Fluorescência , Humanos , Concentração de Íons de Hidrogênio , Porfirinas/química , Ligação Proteica , Conformação Proteica , Solubilidade , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Eletricidade EstáticaRESUMO
Interest in the interaction between cationic porphyrins, particularly derivatives of meso-tetra(N-methylpyridinium-4-yl) porphyrin(TMPyP), and DNA abounds because they are versatile DNA-binding agents that could find application in photodynamic therapy, cancer detection, artificial nucleases, virus inhibition and so on. The interaction of two water-soluble cationic porphyrins, meso-tetrakis(4-N, N, N-trimethylanilinium) porphyrin (TMAP) and 5-phenyl-10,15,20-tris[4-(N-methyl) pyridinium]porphyrin (TriMPyP), with calf thymus DNA (ctDNA) was studied by UV-Vis absorption spectroscopy, fluorescence spectroscopy and resonance light scattering technique. TriMPyP forms aggregate in water due to the molecular asymmetry while TMAP exists as monomers. At lower concentrations of ctDNA (R > 1, R = c(TMAP)/c(DNA) base pair), the interaction of TMAP with DNA leads to significant hypochromicity and bathochromic shift of absorption spectra. And the fluorescence of TMAP was quenched while it showed enhanced resonance light scattering signals. But the extent of enhancement of resonance light scattering signals is very small, so the aggregate of TMAP is not very high. These observations indicate the self-stacking of TMAP along the DNA surface. At higher concentrations of ctDNA (R < 1), TMAP association with DNA is via outside binding which is accompanied with hyperchromic effect and fluorescence enhancement while the resonance light scattering signals is reduced. DNA addition decreases the fluorescence intensity of TriMPyP and it shifts the peak to the higher wavelengths (red shift). The interaction with DNA promotes the aggregation of TriMPyP and no simple outside binding is observed even at higher concentrations of ctDNA. The steric effect of molecular distortion constrains the intercalation or further binding to DNA. The effect of ionic strength on the interaction was investigated at two DNA concentrations, 1.2 and 24.0 micromol x L(-1), for TMAP. The Interactions of both porphyrins with DNA show high sensitivity to ionic strength. By addition of NaCl, electrostatic attraction is decreased, resulting in the change of binding mode.
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DNA/metabolismo , Porfirinas/química , Porfirinas/metabolismo , Absorção , Animais , Bovinos , Luz , Concentração Osmolar , Espalhamento de Radiação , Solubilidade , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Água/químicaRESUMO
In the present paper, the binding characteristics and spectral behavior of interaction of meso-tetra-(3, 5-dibromo-4-hydroxyphenyl) porphyrin [T(DBHP)P] as a new-style probe with protein were studied by the techniques of spectrophotometry. The experiment showed that Tween-80 microemulsion was efficiently used to enhance the sensibility and stability of the system at pH 4. 17(Britton-Robinson buffer solution). Under optimum conditions, the characteristics of absorption spectral of meso-tetra-(3,5-dibromo-4-hydroxyphenyl) porphyrin-protein were investigated, the maximum absorption was located at 425 nm, and the reducing value of absorbance A was in proportion to the concentration of proteins in the range 0.50-6.00 microg x mL(-1) for bovine serum albumin, 0.05-0.60 microg x mL(-1) for ovalbumin, and the limits of detection were 0.106 microg x mL(-1) for bovine serum albumin and 0.039 microg x mL(-1) for ovalbumin. The experiments indicated that the proposed method featured high sensitivity and good selectivity and stability, and was simple and relatively free from interference of coexistent substances. It has been applied to the determination of protein in milk samples with satisfactory. The recovery for the investigated protein from milk was 99.56%-100.2% and the relative standard deviations were less than 2.2%. The sensitive method for the quantitative determination of proteins was proposed and may be applicable to the determination of ultra amounts of protein in food analysis. The effect of ionic strength on the system was investigated, and the result indicated that the binding force between meso-tetra-(3, 5-dibromo-4-hydroxyphenyl) porphyrin and protein was judged as electrostatic force. The influence of protein denaturation was also studied, under higher temperature the structure of protein was destroyed, and thermodynamic movement of the molecular of protein was intensified as the heating time extended.
Assuntos
Proteínas/análise , Espectrofotometria/métodos , Animais , Bovinos , Leite/química , Porfirinas/química , Sensibilidade e Especificidade , TermodinâmicaRESUMO
Studies on the binding mechanism between protein and small molecules could give us lots of useful information. For example, a detailed characterization of drug-protein binding properties was essential for understanding the function of delivery, hence, interest in the mechanism of the interaction between them has attracted much research using different methods. In the present paper, the interaction mechanism between meso-tetra-(3,5-dibromo-4-hydroxyphenyl) porphyrin [T(DBHP)P] and bovine serum albumin (BSA) was investigated using fluorescence method. Based on the mechanisms of fluorescence quenching of BSA caused by T(DBHP)P, the binding constants between T(DBHP)P and BSA were measured at different temperatures. The experiment showed that T(DBHP)P and BSA have strong interactions. The binding constants of the reaction at 27 and 48 degrees C were calculated by fluorescence method, respectively. The binding constants are K = 1.30 x 10(6) L x mol(-1) at 27 degrees C, and K = 6. 32 x 10(5) L x mol(-1) at 48 degrees C. Because the binding constants decreased with increasing the temperature, the sort of quenching between T(DBHP)P and BSA was determined as static quenching. By the theory of Forster non-radiation energy transfer, the binding distance and the energy transfer efficiency at 27 degrees C between T(DBHP)P (accepter of energy) and BSA (donor of energy) were obtained to be 2.39 nm and 0.91, respectively. The binding distance was less than 7 nm, therefore, the interaction was similar to the non-radiation energy transfer, and the static quenching was further proved. According to the thermodynamic parameters, the main sorts of binding force between T(DBHP)P and BSA could be judged as electrostatic force when deltaG <0, deltaH <0 and deltaS >0. Using the synchronous fluorescence spectra, the effect of T(DBHP)P on the conformation of BSA was studied. The results indicated that the conformation of BSA was changed when T(DBHP)P was added, and the hydrophobic properties of the environment of residues in BSA decreased. It was proved that fluorescence quenching of BSA was induced by static quenching and non-radiation energy transfer.
Assuntos
Porfirinas/química , Espectrometria de Fluorescência/métodos , Ligação Proteica , Soroalbumina Bovina/química , TermodinâmicaRESUMO
BACKGROUND: The aim of this study was to explore the associations of haplotypes of the glucose transporter 9 (SLC2A9) genes with type 2 diabetes mellitus (T2DM) complicated with hyperuricemia (HUA). METHODS: Overall, 608 Chinese males, enrolled from the Affiliated Hospital of Medical College of Qingdao University in 2009-2012, were genotyped. The subjects included 167 withT2DM (average age of onset (58.07±11.82 yr), 198 with HUA subjects (average age of onset (39.20±9.73) yr), 115 with T2DM complicated with HUA (average age of onset (51.24±10.09) yr), and 128 control subjects (average age (41.92±10.01) yr). Patients genotypes of the SNPs; including rs734553 was determined by PCR method. Each genotype was regressed assuming the co-dominant, dominant and the recessive models of inheritance with covariates of duration of total glucose, uric acid, urea nitrogen, triglyceride, cholesterol, and creatinine levels. RESULTS: Chi-square test revealed that rs734553polymorphism was both significantly associated with HUA as well as T2DM complicated HUA, but not with pure T2DM. After adjustment for age and gender, analysis showed that people with C allele had higher risk of HUA and T2DM complicated HUA than those without C allele. And none of the subjects had the homozygous genotype for SLC2A9 (CC). CONCLUSION: The SLC2A9 mutation increases the risk for T2DM complicated HUA in Chinese population, which suggested that intron variants between two relatively conserved exons could also be associated with diseases. In patients of T2DM complicated with HUA, the diagnosis and detection of SLC2A9 gene variants should be caused enough attention.
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The binding characteristics of meso-tetra-(3, 5-dibromo-4-hydroxphenyl) porphyrin [T(DBHP)P] with calf thymus DNA (ct DNA) in pH 4.92 HAc-NaAc buffer solution were studied by the techniques of spectrophotometry. At the maxium absorption wavelength for T(DBHP)P, the decrease in the absorbance was linear with the amount of ct DNA. The experiments indicated that under optimum conditions, ct DNA obeys Beer's law in the range of 0.20-1.80 microg x mL(-1), and the limit of detection is 0.024 microg x mL(-1). Tween-80 microemulsion was commended in the experiment for better sensitivity. Furthermore, the association number is also determined by molar ratio method. The interactional mechanism between ct DNA and (T(DBHP)P was investigated as well.
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DNA/química , Porfirinas/análise , Espectrofotometria/métodos , Animais , Bovinos , Porfirinas/químicaRESUMO
Porphyrin and metalloporphyrin distribute widely in nature and they play an important role in the life. Synthesis of porphyrin compounds with special function has been the focus of attention. In the present paper, porphyrin and metalloporphyrin compound were synthesized by the following method: by one-step synthesis, tetra-(dimethylaminophenyl) porphyrin (T(DMAP) P) was synthesized with propionic acid, acetic acid and nitrobenzene as solvent and 4-dimethylaminobenzaldehyde and pyrrole as raw material. The yield was 24.24%. The complexes of T(DMAP)P with Zn2+, Mn2+ and Tb3+ were synthesized by solvent of chloroform-N, N dimethylformamide (1 : 1). The effects of solvent, temperature and reaction time on the reaction were discussed. Optimum proportion between porphyrin and metallic salts was studied also and the molar ratios of T(DMAP)P to Zn (CH3COO)2 x 2H2O, T(DMAP)P to MnCl2 x 4H2O, and T(DMAP)P to TbCl3 were 1 : 1.2, 1 : 1.4, 1 : 1.5, respectively. The synthesis of metalloporphyrins under mild conditions is simper with high yield (94.2%, 91.7% and 90.5% for T(DMAP) P combined with Zn2+ , Mn2+ and Tb3+ respectively) and the unstability of metalloporphyrin could be avoided. The constitution and structures of these compounds were studied by elemental analyses, infrared spectrum (IR), and ultraviolet-visible spectrum (UV-Vis). The conductivity of porphyrin compound with different concentration and temperature was studied. It was found that the molar conductivity of T(DMAP)P-TbCl(74.6 s x cm(-2) mol(-1)) was greater than that of T(DMAP)P-Zn (8. 8 s x cm(-2) x mol(-1)) and T(DMAP)P-Mn (25.8 s X cm(-2) mol(-1)). So T(DMAP) P-TbCl could be regarded as the 1 : 1 electrolyte compound while T(DMAP)P-Zn and T(DMAP)P-Mn were non-electrolyte compounds. The influences of different metal ions on the reaction were investigated. The discussion was concentrated on the molecular spectra of porphyrin and metalloporphyrin. Compared with tetraphenyl porphyrin, the absorption of T(DMAP) P and its metal complexes had red-shifts due to the substituent groups and metal ions. When the porphyrin rings were occupied by metal ions, the number of Q band decreased and the absorption peak intensity decreased. Among these metalloporphyrin compounds, the maximum absorption of T(DMAP)P-TbCl had the biggest red-shifts and could be used as ideal photosensitizer.
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Metaloporfirinas/síntese química , Metais/química , Porfirinas/síntese química , Metaloporfirinas/química , Porfirinas/química , Análise EspectralRESUMO
The mechanism of interaction between bovine serum albumin (BSA) and trihydroxylphenylfluorone (TH-PF)-Mo(VI) complex in neutral solution was studied by fluorimetric method. The mechanism of fluorescence quenching of BSA caused by (TH-PF)-Mo(VI) complex probe was investigated and the binding constants under different temperature were measured. The binding constants of the reaction at 25 degrees C and 40 degrees C were calculated by fluorimetric method to be 4.78 x 10(4) L x mol(-1) and 3.72 x 10(4) L x mol(-1), respectively. According to the theory of Forster non-radiation energy transfer, the binding distance and transfer efficiency at 25 degrees C were calculated to be 2.89 nm and 0.314, respectively. Furthermore, the thermodynamic parameters were measured and the results indicated that electrostatic force played a major role in the interaction between TH-PF-Mo(VI) complex and BSA.
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Fluoresceínas/química , Fluorometria , Molibdênio/química , Soroalbumina Bovina/química , Animais , BovinosRESUMO
Kosinostatin (KST), an antitumor antibiotic, features a pyrrolopyrrole moiety spirally jointed to a five-membered ring of an anthraquinone framework glycosylated with a γ-branched octose. By a combination of in silico analysis, genetic characterization, biochemical assay, and precursor feeding experiments, a biosynthetic pathway for KST was proposed, which revealed (1) the pyrrolopyrrole moiety originates from nicotinic acid and ribose, (2) the bicyclic amidine is constructed by a process similar to the tryptophan biosynthetic pathway, and (3) a discrete adenylation enzyme and a peptidyl carrier protein (PCP) are responsible for producing a PCP-tethered building block parallel to type II polyketide synthase (PKS) rather than for the PKS priming step by providing the starter unit. These findings provide an opportunity to further explore the inexplicable enzymatic logic that governs the formation of pyrrolopyrrole moiety and the spirocyclic skeleton.
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Aminoglicosídeos/biossíntese , Antibacterianos/biossíntese , Antineoplásicos/metabolismo , Pirróis/química , Aminoglicosídeos/química , Antibacterianos/química , Antineoplásicos/química , Sequência de Bases , Clonagem Molecular , Espectroscopia de Ressonância Magnética , Micromonospora/genética , Micromonospora/metabolismo , Conformação Molecular , Dados de Sequência Molecular , Família Multigênica , Peptídeo Sintases/metabolismo , Policetídeo Sintases/genética , Policetídeo Sintases/metabolismoRESUMO
A new reductase, CgKR2, with the ability to reduce ethyl 2-oxo-4-phenylbutyrate (OPBE) to ethyl (R)-2-hydroxy-4-phenylbutyrate ((R)-HPBE), an important chiral precursor for angiotensin-converting enzyme (ACE) inhibitors, was discovered. For the first time, (R)-HPBE with >99% ee was produced via bioreduction of OPBE at 1 M without external addition of cofactors. The space-time yield (700 g·L(-1)·d(-1)) was 27 times higher than the highest record.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/síntese química , Oxirredutases/metabolismo , Fenilbutiratos/síntese química , Inibidores da Enzima Conversora de Angiotensina/química , Inibidores da Enzima Conversora de Angiotensina/metabolismo , Candida/enzimologia , Escherichia coli/efeitos dos fármacos , Estrutura Molecular , Paracoccus pantotrophus/enzimologia , Fenilbutiratos/química , Fenilbutiratos/metabolismo , EstereoisomerismoRESUMO
OBJECTIVE: To investigate the risk factors related with distant metastases (DM) from head and neck squamous cell carcinomas (HNSCC). METHODS: A retrospective study was carried out to review the histopathological data from 532 HNSCC patients treated in Bethune International Peace Hospital from February 1978 to February 1998. The incidence and the risk factor for DM were evaluated in a model that included the following factors: sex, age, clinical staging, T and N staging, site of primary tumor, depth of primary tumor infiltration, histological grade of primary tumor, presence of cervical lymph node metastasis, number of positive neck nodes and levels involved, and presence of extracapsular nodal spread. Univariate chi2 test and multivariate stepwise logistic regression model were used for the analysis. Statistical analysis of overall survival was performed using Kaplan-Meier method. RESULTS: Sixty cases (11.3%) presented distant metastases in 532 patients of head and neck squamous cell carcinomas. In a univariate analysis, it was confirmed that the following variables correlated to DM, i.e., clinical staging (P = 0.0126), T classification (P = 0.0082), site of primary tumor (P = 0.0011), depth of primary tumor infiltration (P = 0.0005) , presence of cervical metastasis (P = 0.0057), number of positive neck nodes (P = 0.0149) and levels involved (P = 0.0034), presence of extracapsular nodal spread (P = 0.0118). In a multivariate analysis, the most significant risk factors for DM were the site of primary tumor and the depth of primary tumor infiltration. Kaplan-Meier analysis showed that overall survival rates of 60 HNSCC patients who presented distant metastases were 51.7% at 1 year, 13.3% at 3 years, 6.5% at 5 years, respectively. CONCLUSION: The site of primary tumor and the depth of primary tumor infiltration are the key risk factors in determining the development of DM in HNSCC patients. Patients with laryngeal and hypopharyngeal carcinomas and patients with primary tumor infiltrating muscular, bone or cartilage level have the highest risk of developing DM.
Assuntos
Carcinoma de Células Escamosas/secundário , Neoplasias de Cabeça e Pescoço/patologia , Linfonodos/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pescoço , Metástase Neoplásica , Estudos Retrospectivos , Fatores de RiscoRESUMO
A facile and efficient approach for the fabrication of mesoporous spherical aggregates of anatase nanocrystals is reported in this paper. Cetyltrimethylammonium bromide was used as the structure-directing agent, and the interaction between cyclohexane microdroplets and the cetyltrimethylammonium bromide self-assemblies led to the assembly of 4-5-nm-sized anatase nanocrystals into spherical aggregates with mesoporous structures. The as-prepared anatase powders exhibited high photocatalytic activity and could be effectively used as the catalyst for the room-temperature photodegradation of a variety of organic dye pollutants in aqueous media including methyl orange, bromopyrogallol red, and methylene blue.
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OBJECTIVE: To investigate the risk clinicopathological factors of primary tumor in the prediction of cervical lymph node metastases and the cervical lymph node prognostic factors in hypopharyngeal squamous cell carcinoma. METHODS: A retrospective study was carried out to review the histopathological data from 98 hypopharyngeal squamous cell carcinoma patients. The relationship between histopathological parameters and cervical lymph node metastases were evaluated by means of a univariate chi2 test and multivariate stepwise logistic regression model. And the Cox regression model was used to define possible pathological parameters of neck node affecting survival including N staging, presence of cervical lymph node metastases and extracapsular nodal spread, size and number of positive neck nodes, and levels of positive neck nodes. RESULTS: The overall 5-year survival rate of patients with hypopharyngeal carcinoma was 28.6%. In a univariate and multivariate analysis, it was confirmed that size and growth pattern of primary tumor correlated to cervical lymph node metastases. In a multivariate Cox regression analysis, the most significant prognostic factors of cervical lymph node were the size of positive neck nodes and level involved. CONCLUSIONS: Cervical lymph node metastases were one of the most significant prognostic factors of hypopharyngeal carcinoma. The identification of patients at risk for cervical lymph node metastases and the management of the neck by coping with pathological factors of cervical lymph node affecting survival are very important to improve the treatment and prognosis of hypopharyngeal carcinoma.