Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Chemistry ; 29(65): e202303433, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37933716

RESUMO

Invited for the cover of this issue are Sudipta Roy and co-workers at the Indian Institute of Science Education and Research (IISER) Tirupati. The image depicts the rearrangement of cyclic alkyl(amino) carbene (cAAC)-supported chloro-phosphinidenes affording two ligands, of which one was used for the solid-state isolation of three cyclic alkyl(amino-boryl) phosphaalkenes and two coinage metal clusters. Read the full text of the article at 10.1002/chem.202302120.

2.
Chemistry ; 29(65): e202302120, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37665314

RESUMO

Two-electron reduction of cyclic alkyl(amino) carbene (cAAC)-supported chloro-phosphinidene cAAC=P-Cl (1) followed by unprecedented thermal rearrangements afforded the alkali metal complexes of (aryl)-(cyclic alkyl(imino)) phosphides 3 a-3 c, 4 a-4 b through migration of the 2,6-diisopropylphenyl (dipp) group from N to the P centre, and the (aryl)-(cyclic alkyl(phosphaalkene)) amide 5 through cleavage of the CMe2 -N bond followed by energetically favoured 5-exo-tet ring-closure in the presence of the alkali metals Cs (3 a-3 c), K (4 a, 4 b), and Li (5). Compound 3 a was found to be photoluminescent (PL), emitting bright orange light under a laboratory UV lamp of wavelength 365 nm with PL quantum yield (ϕPL ) of 2.6 % (λem =600 nm), and an average lifetime (τ) of 4.8 µs. Reaction of 3 a with CuCl and AgOTf afforded (aryl)-(cyclic alkyl(imino)) phosphide-stabilized tetra-nuclear CuI (6), and octa-nuclear AgI (7) clusters, respectively. Moreover, complexes 3 a-3 c provided a direct route for the stabilization of cyclic alkyl(aminoboryl) phosphaalkenes 8 a-8 c when treated with 1-bromo-N,N,N',N'-tetraisopropylboranediamine.

3.
Int J Immunogenet ; 50(5): 249-255, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37658479

RESUMO

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease. Chronic HCV infection is also an important cause of hepatic fibrosis, cirrhosis and hepatocellular carcinoma (HCC). HCV has the capacity to evade immune surveillance by altering the host immune response. Moreover, variations in immune-related genes can lead to differential susceptibility to HCV infection as well as interfere on the susceptibility to the development of hepatic fibrosis, cirrhosis and HCC. The human leucocyte antigen G (HLA-G) gene codes for an immunomodulatory protein known to be expressed in the maternal-foetal interface and in immune-privileged tissues. The HLA-G 3' untranslated region (3'UTR) is important for mRNA stability, and variants in this region are known to impact gene expression. Studies, mainly focusing in a 14 bp insertion/deletion polymorphism, have correlated HLA-G 3'UTR with susceptibility to viral infections, but other polymorphic variants in the HLA-G 3'UTR might also affect HCV infection as they are inherited as haplotypes. The present study evaluated HLA-G 3'UTR polymorphisms and performed linkage disequilibrium test and haplotype assembly in 286 HCV infected patients who have developed fibrosis, cirrhosis or HCC, as well as in 129 healthy control subjects. Haplotypes UTR-1, UTR-2 and UTR-3 were the most observed in HCV+ patients, in the frequencies of 0.276, 0.255 and 0.121, respectively. No statistically significant difference was observed between HCV+ and control subjects, even when patients were grouped according to outcome (HCC, cirrhosis or fibrosis). Despite that, some trends in the results were observed, and therefore, we cannot rule out the possibility that variants associated to high HLA-G expression can be involved in HCV infection susceptibility.


Assuntos
Carcinoma Hepatocelular , Hepatite C , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Regiões 3' não Traduzidas/genética , Hepacivirus , Antígenos HLA-G/genética , Haplótipos/genética , Neoplasias Hepáticas/genética , Cirrose Hepática/genética , Hepatite C/complicações , Hepatite C/genética
4.
Chemistry ; 28(54): e202201242, 2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-35727715

RESUMO

The elusive phosphinidene-chlorotetrylenes, [PGeCl] and [PSiCl] have been stabilized by the hetero-bileptic cyclic alkyl(amino) carbene (cAAC), N-heterocyclic carbene (NHC) ligands, and isolated in the solid state at room temperature as the first neutral monomeric species of this class with the general formulae (L)P-ECl(L') (E=Ge, 3 a-3 c; E=Si, 6; L=cAAC; L'=NHC). Compounds 3 a-3 c have been synthesized by the reaction of cAAC-supported potassium phosphinidenides [cAAC=PK(THF)x ]n (1 a-1 c) with the adduct NHC:→GeCl2 (2). Similarly, compound 6 has been synthesized via reaction of 1 a with NHC:→SiCl2 adduct (4). Compounds 3 a-3 c, and 6 have been structurally characterized by single-crystal X-ray diffraction, NMR spectroscopy and mass spectrometric analysis. DFT calculations revealed that the heteroatom P in 3 bears two lone pairs; the non-bonding pair with 67.8 % of s- and 32 % of p character, whereas the other lone pair is involved in π backdonation to the CcAAC -N π* of cAAC. The Ge atom in 3 contains a lone pair with 80 % of s character, and slightly involved in the π backdonation to CNHC . EDA-NOCV analyses showed that two charged doublet fragments {(cAAC)(NHC)}+ , and {PGeCl}- prefer to form one covalent electron-sharing σ bond, one dative σ bond, one dative π bond, and a charge polarized weak π bond. The covalent electron-sharing σ bond contributes to the major stabilization energy to the total orbital interaction energy of 3, enabling the first successful isolations of this class of compounds (3, 6) in the laboratory.

5.
Chemistry ; 27(1): 200-206, 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-32810317

RESUMO

Cyclic alkyl(amino) carbene (cAAC)-supported, structurally diverse alkali metal-phosphinidenides 2-5 of general formula ((cAAC)P-M)n (THF)x [2: M=K, n=2, x=4; 3: M=K, n=6, x=2; 4: M=K, n=4, x=4; 5: M=Na, n=3, x=1] have been synthesized by the reduction of cAAC-stabilized chloro-phosphinidene cAAC=P-Cl (1) utilizing metallic K or KC8 and Na-naphthalenide as reducing agents. Complexes 2-5 have been structurally characterized in solid state by NMR studies and single crystal X-ray diffraction. The proposed mechanism for the electron transfer process has been well-supported by cyclic voltammetry (CV) studies and Density Functional Theory (DFT) calculations. The solid state oligomerization process has been observed to be largely dependent on the ionic radii of alkali metal ions, steric bulk of cAAC ligands and solvation/de-solvation/recombination of the dimeric unit [(cAAC)P-M(THF)x ]2 .

6.
Acta Odontol Scand ; 78(2): 141-145, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31519120

RESUMO

Objective: This study evaluated human leucocyte antigen-G gene polymorphisms in patients with periodontitis and healthy controls.Material and methods: The insertion/deletion polymorphism of 14 bp and a single nucleotide polymorphism (SNP) C > G on the position +3142 of the 3' untranslated region of the gene were analyzed in chronic periodontitis (n = 62), aggressive periodontitis (n = 24) patients and healthy individuals (n = 47).Results: Considering the 14 bp insertion/deletion, a significant deviation from Hardy-Weinberg expectations in the chronic periodontitis group was observed, but not in the other groups. No significant deviations were observed in patients and control groups considering the +3142 C > G SNP. A significant increased frequency of homozygotes for the 14 bp deletion allele was observed in the chronic periodontitis group as compared to controls. This group also presented a higher frequency of the deletion allele, which was marginally not significant. Concerning this polymorphism, no significant differences were observed between the aggressive periodontitis and healthy control groups. In addition, no significant differences were seen amongst patients and controls when considering the +3142 C > G frequencies.Conclusion: No differences were found amongst patients and controls when considering the +3142 C > G SNP haplotypes frequencies, but a significant increased frequency of homozygotes for the 14 bp deletion allele was observed in chronic periodontitis patients compared to healthy controls, suggesting a susceptibility role of this polymorphism in the pathogenesis of this condition.


Assuntos
Periodontite Agressiva , Periodontite Crônica , Antígenos HLA-G , Polimorfismo de Nucleotídeo Único , Periodontite Agressiva/genética , Alelos , Estudos de Casos e Controles , Periodontite Crônica/genética , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Antígenos HLA , Antígenos HLA-G/genética , Humanos
7.
J Assist Reprod Genet ; 36(5): 995-1002, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30937706

RESUMO

PURPOSE: Idiopathic recurrent pregnancy loss (RPL) is a multifactorial reproductive disorder where an impaired control of apoptosis is likely involved. Triggering the cell death mechanism occurs in a spatiotemporal manner and is strongly related to a healthy pregnancy. Single nucleotide polymorphisms (SNPs) at the regulatory regions of genes are known to influence the expression patterns of apoptosis-related molecules. METHODS: A total of 296 unrelated female Brazilian patients were evaluated for clinical-demographic variables and genetic factors: 140 women who had experienced an unexplained RPL (with at least two consecutive abortions) and 156 healthy multiparous women. In all patients, six SNPs were evaluated in genes of apoptosis-related pathways: FAS (rs2234767, rs1800682), FAS-L (rs763110, rs5030772), BAX (rs4645878), and BCL-2 (rs2279115) by PCR followed by a restriction fragment length polymorphism (RFLP)-based analysis. RESULTS: The BAX-248GA genotype is independently associated with idiopathic RPL [adjusted OR = 0.30, 95% CI 0.13-0.70, P = 0.005] susceptibility. In the same multivariate model, the variables ethnicity, smoking, and alcohol consumption were statistically associated with RPL susceptibility (P < 0.05). No association with RPL susceptibility was reported for the remaining SNPs. CONCLUSION: Our study is the first to evaluate the role of the main SNPs from both the extrinsic and intrinsic apoptosis pathways in RPL susceptibility. The association of BAX-248G/A with RPL susceptibility suggests that maternal predisposition for RPL has an essential contribution from genes involved in the delicate balance of endometrium cell turnover (cell death/proliferation). Therefore, apoptotic genes may represent promising targets for future studies on healthy pregnancies and the spectrum of pregnancy disorders.


Assuntos
Aborto Habitual/genética , Proteína Ligante Fas/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteína X Associada a bcl-2/genética , Receptor fas/genética , Adolescente , Adulto , Estudos de Casos e Controles , Feminino , Genótipo , Humanos , Gravidez , Prognóstico , Adulto Jovem
8.
Chem Asian J ; 19(2): e202300882, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38009659

RESUMO

The stability and reactivity studies of heavier di-atomic group-15 congeners of alkynes, e. g., the di-phosphorus (P≡P) compounds have been the topic of huge interest because of their contrasting transient properties and lower stability compared to those of the stable molecular di-nitrogen (N≡N). Herein, we depict the reactivity studies of the bis-cAAC-stabilized di-phosphorus (P2 ) having an inversely polarized phosphaalkene nature featuring the C=P double bonds with Au(I)Cl. Both the mono-, and the di-aurated phosphaalkenes with the formulae [(Me2 -cAAC=P)2 (AuCl)] (2), and [(Me2 -cAAC=P)2 (AuCl)2 ] (3), respectively have been isolated in the solid state. Moreover, for the first time, we have been able to isolate the cAAC-stabilized tetra-aurated elusive di-phosphorus-monoxide (P2 O) with the formula [(Cy-cAAC=P)-O-(P=cAAC-Cy)(AuCl)4 ] (5) in presence of oxygen. Complexes 2-3, 5 have been structurally characterized by single crystal X-ray diffraction, and further studied by NMR spectroscopy. Our findings reveal significant elongation of the CcAAC -P bonds in 2-3, 5, and the presence of aurophilic interaction in 5. Quantum chemical calculations, including density functional theory (DFT), and energy decomposition analysis coupled with natural orbitals for chemical valence (EDA-NOCV) have been performed to study the electron densities distribution and nature of bonding in 2-3, 5.

9.
RSC Adv ; 13(12): 7738-7751, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36909773

RESUMO

Gallium phosphide is a three-dimensional polymeric material of the hetero-diatomic GaP unit, which has a wurtzite type structure, and captivating application as a light emitting diode (LED). As a result, there is a constant search for suitable precursors to synthesise GaP-based materials. However, the corresponding monomeric species is exotic in nature due to the expected Ga[triple bond, length as m-dash]P multiple bond. Herein, we report on the theoretical studies of stability, chemical bonding, and reactivity of the monomeric gallium phosphides with two donor base ligands having tuneable binding energies. We have performed detailed investigations using density functional theory at three different levels (BP86/def2-TZVPP, B3LYP/def2-TZVPP, M06-2X/def2-TZVPP), QTAIM and EDA-NOCV (BP86-D3(BJ)/TZ2P, M06-2X/TZ2P) to analyse various ligand-stabilised GaP monomers, which revealed the synthetic viability of such species in the presence of stable singlet carbenes, e.g., cAAC, and NHC as ligands [cAAC = cyclic alkyl(amino) carbene, NHC = N-heterocyclic carbene] due to the larger bond dissociation energy compared to a phosphine ligand (PMe3). The calculated bond dissociation energies between a pair of ligands and the monomeric GaP unit are found to be in the range of 87 to 137 kcal mol-1, predicting their possible syntheses in the laboratory. Further, the reactivity of such species with metal carbonyls [Fe(CO)4, and Ni(CO)3] have been theoretically investigated.

10.
ACS Omega ; 7(7): 5730-5738, 2022 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35224333

RESUMO

Herein, we report on the stability and bonding analysis of donor-base-stabilized monomeric AlP species (1-6) of the general formula (L)P-Al(L'); [L = cAACMe, L' = cAACMe, NHCMe, PMe3, (N i Pr2)2 (1-4); L = L' = NHCMe, PMe3 (5 and 6); cAAC = cyclic alkyl(amino) carbene; NHC = N-heterocyclic carbene]. Energy decomposition analysis coupled with natural orbitals for chemical valence (EDA-NOCV) analysis indicates the synthetic viability of this class of species, stabilized in their singlet ground state, in the laboratory. The CL-P bond is found to be a partial double bond (WBI ∼ 1.45), while the CL/PL-Al bond is a single bond (WBI ∼ 0.42-0.69). These bonds are mostly covalent or dative σ/π bonds depending upon the ligands attached. The central P-Al bond is an electron-sharing covalent polar single bond (WBI ∼ 0.80; P-Al) for 1-4 and a dative σ bond for 5 and 6 (WBI ∼ 0.89-0.93; P-Al). The calculated intrinsic interaction energies of the central P-Al bonds are found to be in the range from -116 to -216 kcal/mol (1-3 and 5 and 6). This value is the highest for compound 3, possibly due to the push and pull effects from the ligands PMe3 and cAAC, respectively.

11.
Dalton Trans ; 51(5): 1791-1805, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-35023531

RESUMO

(Tip)2SbCl (1, Tip = 2,4,6-triisopropylphenyl) has been utilized as a precursor for the synthesis of the distibane (Tip)4Sb2 (4) via one-electron reduction using KC8. The two-electron reduction of 1 and 4 afforded the novel trinuclear antimonide cluster [K3((Tip)2Sb)3(THF)5] (6). Changing the reducing agent from KC8 to a different alkali metal resulted in the solid-state isolation of corresponding stable dimeric alkali metal antimonides with the general formula [M2((Tip)2Sb)2(THF)p-x(tol)x] (M = Li (14), Na (15), Cs (16)). In this report, different aspects of the various reducing agents [K metal, KC8, and [K2(Naph)2(THF)]] used have been studied, correlating the experimental observations with previous reports. Additional reactivity studies involving 1 and AgNTf2 (Tf = trifluoromethanesulfonyl) afforded the corresponding antimony cation (Tip)2Sb+NTf2- (19). The Lewis acidic character of 19 has been unambiguously proved via treatment with Lewis bases to produce the corresponding adducts 20 and 21. Interestingly, the precursors 1 and 4 have been observed to be highly luminescent, emitting green light under short-wavelength UV radiation. All the reported compounds have been characterized via NMR, UV-vis, mass spectrometry, and single-crystal X-ray diffraction analysis. Cyclic voltammetry (CV) studies of 1 in THF showed possible two electron reduction, suggesting the in situ generation of the corresponding radical-anion intermediate 1˙- and its subsequent conversion to the monomeric intermediate (Tip)2Sb- (5) upon further reduction. 5 undergoes oligomerization in the solid state to produce 6. The existence of 1˙- was proved using electron paramagnetic resonance (EPR) spectroscopy in solution. CV studies of 6 suggested its potential application as a reducing agent, which was further proved via the conversion of Tip-PCl2 to trimeric (Tip)3P3 (17), and cAACP-Cl (cAAC = cyclic alkyl(amino)carbene) to (cAAC)2P2 (18) and 4, utilizing 6 as a stoichiometric reducing agent.

12.
RSC Adv ; 11(12): 6586-6603, 2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35423226

RESUMO

Fluoro- and chloro-phosphasilynes [X-Si[triple bond, length as m-dash]P (X = F, Cl)] belong to a class of illusive chemical species which are expected to have Si[triple bond, length as m-dash]P multiple bonds. Theoretical investigations of the bonding and stability of the corresponding Lewis base-stabilized species (L')PSi(X)(L) [L' = cAACMe (cyclic alkyl(amino) carbene); L = cAACMe, NHCMe (N-heterocyclic carbene), PMe3, aAAC (acyclic alkyl(amino) carbene); X = Cl, F] have been studied using the energy decomposition analysis-natural orbitals for chemical valence (EDA-NOCV) method. The variation of the ligands (L) on the Si-atom leads to different bonding scenarios depending on their σ-donation and π-back acceptance properties. The ligands with higher lying HOMOs prefer profoundly different bonding scenarios than the ligands with lower lying HOMOs. The type of halogen (Cl or F) on the Si-atom was also found to have a significant influence on the overall bonding scenario. The reasonably higher value and endergonic nature of the dissociation energies along with the appreciable HOMO-LUMO energy gap may corroborate to the synthetic viability of the homo and heteroleptic ligand-stabilized elusive PSi(Cl/F) species in the laboratory.

13.
Biosensors (Basel) ; 11(7)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201480

RESUMO

The treatment of refractory epilepsy via closed-loop implantable devices that act on seizures either by drug release or electrostimulation is a highly attractive option. For such implantable medical devices, efficient and low energy consumption, small size, and efficient processing architectures are essential. To meet these requirements, epileptic seizure detection by analysis and classification of brain signals with a convolutional neural network (CNN) is an attractive approach. This work presents a CNN for epileptic seizure detection capable of running on an ultra-low-power microprocessor. The CNN is implemented and optimized in MATLAB. In addition, the CNN is also implemented on a GAP8 microprocessor with RISC-V architecture. The training, optimization, and evaluation of the proposed CNN are based on the CHB-MIT dataset. The CNN reaches a median sensitivity of 90% and a very high specificity over 99% corresponding to a median false positive rate of 6.8 s per hour. After implementation of the CNN on the microcontroller, a sensitivity of 85% is reached. The classification of 1 s of EEG data takes t=35 ms and consumes an average power of P≈140 µW. The proposed detector outperforms related approaches in terms of power consumption by a factor of 6. The universal applicability of the proposed CNN based detector is verified with recording of epileptic rats. This results enable the design of future medical devices for epilepsy treatment.


Assuntos
Redes Neurais de Computação , Convulsões/diagnóstico , Algoritmos , Animais , Encéfalo , Eletroencefalografia , Epilepsia , Humanos , Ratos
14.
RSC Adv ; 11(37): 22849-22858, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-35480420

RESUMO

A robust tetrameric nickel complex [Ni4((Oal -)2L-Me)4(s)4] (3) (s = solvent) with cubane-like Ni4O4 core topology was isolated as a light greenish-orange crystalline solid in excellent yield. The mechanism of formation of 3 involving the two chloride-containing precursors [Ni4((Oal -)2L-Me)4(s)4]·2MeOH (1) and [Ni4((O-)2L-Me)3((Oal -)(OH)L-Me)Cl] (2) was studied by ESI mass spectrometry and confirmed by the solid state isolation and single-crystal X-ray diffraction. The challenging ligand fields containing mono/di-anionic O2N donating atoms and/or chloride ions stabilized the pentacoordinate Ni(ii) ions in 1-2 upon controlling the experimental conditions. Complexes 1-3 have been characterized by NMR, UV-Vis and mass spectrometric analysis. Complex 3 was found to be redox active by cyclic voltammetry (CV) studies. Theoretical calculations were carried out to shed light on the effects of ligand fields on the stability of complexes 1-3. Complex 3 was found to be a potential catalyst for the diastereoselective cyclopropanation of heteroarenes with good to excellent yields. The ESI mass spectrometric analysis revealed the existence of solution dynamics and oligomerization of 3 in solution. Mechanistic investigation of the catalytic cycle revealed that complex 3 and its various oligomers bind to the diazoester employed, followed by dissociative insertion of the respective carbene moieties to the C2-C3 double bond of the involved aromatic heterocycle, leading to the diastereoselective cyclopropanation.

15.
RSC Adv ; 10(65): 39366-39372, 2020 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-35515404

RESUMO

Two alkyl substituted triaryl-cyclopentadienyl ligands [4,4'-(4-phenylcyclopenta-1,3-diene-1,2-diyl)bis(methylbenzene) (1) and 4,4',4''-(cyclopenta-1,3-diene-1,2,4-triyl)tris(methylbenzene) (2)] have been synthesized via cross-aldol condensation followed by Zn-dust mediated cyclization and acid catalyzed dehydration reactions. The fluorescence properties of 1 and 2 have been studied in solution and solid state. The ligands exhibited aggregation-induced emission enhancement (AIEE) in THF/water solution. 1 and 2 have been found to be significantly more fluorescent in the solid state than in their respective solutions. This phenomenon can be attributed to the strong intermolecular CH⋯π interactions present in 1 and 2 which leads to the tight packing of molecules in their solid-state. Both 1, 2 and their corresponding anions have been studied by theoretical calculations. Ligands 1 and 2 have been shown to react with anhydrous DyCl3 in the presence of potassium metal at high temperature to afford two fluorescent chloride-bridged tetra-nuclear mixed potassium-dysprosium metallocenes [(Me2Cp)4Dy2 IIICl4K2]·3.5(C7H8) (5) and [(Me3Cp)4Dy2 IIICl4K2]·3(C7H8) (6), respectively in good yields.

16.
Front Immunol ; 9: 1316, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29963045

RESUMO

MicroRNAs (miRNAs) are single-stranded sequences of non-coding RNA with approximately 22 nucleotides that act posttranscriptionally on gene expression. miRNAs are important gene regulators in physiological contexts, but they also impact the pathogenesis of various diseases. The role of miRNAs in viral infections has been explored by different authors in both population-based as well as in functional studies. However, the effect of miRNA polymorphisms on the susceptibility to viral infections and on the clinical course of these diseases is still an emerging topic. Thus, this review will compile and organize the findings described in studies that evaluated the effects of genetic variations on miRNA genes and on their binding sites, in the context of human viral diseases. In addition to discussing the basic aspects of miRNAs biology, we will cover the studies that investigated miRNA polymorphisms in infections caused by hepatitis B virus, hepatitis C virus, human immunodeficiency virus, Epstein-Barr virus, and human papillomavirus. Finally, emerging topics concerning the importance of miRNA genetic variants will be presented, focusing on the context of viral infectious diseases.

17.
Hum Immunol ; 78(11-12): 718-723, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28941746

RESUMO

BACKGROUND: The human leukocyte antigen G (HLA-G) is a molecule involved in immune system modulation, acting in the maintenance of a state of immune tolerance. Some polymorphisms in the HLA-G gene 3' untranslated region (3'UTR) were associated to distinct levels of HLA-G expression and to sepsis development. In the present study, haplotypes and polymorphisms of the HLA-G 3'UTR were analyzed in Brazilian septic patients. METHODS: The HLA-G 3'UTR was amplified by PCR, sequenced and eight polymorphisms were genotyped (the 14bp insertion/deletion, +3003T/C, +3010C/G, +3027A/C, +3035C/T, +3142G/C, +3187A/G and+3196C/G) in DNA samples from septic patients (with severe sepsis or septic shock) and controls. The haplotypes were inferred and association tests were performed through Chi square test and binary logistic regression. RESULTS: The+3027AC genotype was associated asa risk factor to sepsis development (OR 3.17, PBonferroni 0.048). Further, the presence of the UTR-7 haplotype (OR 2.97, PBonferroni 0.018), and of 14bp-Ins_+3142G_+3187A haplotype (OR 2.39, PBonferroni 0.045) were associated with sepsis, conferring susceptibility. CONCLUSION: Our data confirm an important role of HLA-G 3'UTR polymorphisms in the development of severe forms of sepsis (severe sepsis and septic shock). The genotyping of HLA-G genetic variants and haplotypes could be useful as a prediction tool of increased risk to severe sepsis.


Assuntos
Regiões 3' não Traduzidas/genética , Genótipo , Antígenos HLA-G/genética , Sepse/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil , Progressão da Doença , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Haplótipos , Humanos , Tolerância Imunológica , Pessoa de Meia-Idade , Polimorfismo Genético , Adulto Jovem
18.
Hum Immunol ; 77(10): 892-897, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27397898

RESUMO

HLA-G is a molecule essential to the maintenance of the maternal-fetal interface tolerance, thus contributing to a healthy pregnancy. Here we investigate the role of HLA-G single nucleotide polymorphisms (SNPs) and whether a specific HLA-G haplotype influence or not recurrent pregnancy loss (RPL) risk. A total of 296 DNA samples from RPL (N=140) and controls (N=156) were evaluated. The HLA-G 3'UTR region was sequenced and eight major SNPs were evaluated (14pb insertion/deletion, +3003T/C, +3010C/G, +3027C/A, +3035C/T, +3142G/C, +3187A/G, +3196C/G). A high linkage disequilibrium (LD) among all pairs and a perfect LD between +3010C/G and +3142G/A (D'=1.0, r(2)=1.0) were observed. Our data showed an increased risk to +3010CC genotype carriers in comparison with control [odds ratio (OR) 2.05 95% confidence interval (CI) 1.05-4.00, p=0.035] and to a decreased risk of RPL in +3142CC genotype carriers (OR=0.49 95%CI 0.25-0.95, p=0.035) and +3187AG genotype carriers (OR=0.58 95%CI 0.35-0.94, p=0.029). A total of eight haplotypes were observed in the sample, being UTR-1 and UTR-2 the most represented. An association between UTR-1 haplotype carriers with a reduced risk of both RPL and secondary RPL was observed. Our results indicate that the HLA-G 3'UTR plays important roles in RPL and might be an important marker of susceptibility to this, and possible to other, pregnancy disorders.


Assuntos
Regiões 3' não Traduzidas/genética , Aborto Habitual/genética , Rejeição de Enxerto/genética , Antígenos HLA-G/genética , Tolerância ao Transplante , Adolescente , Adulto , População Negra , Brasil , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Haplótipos , Humanos , Polimorfismo de Nucleotídeo Único , Gravidez , Tolerância ao Transplante/genética , População Branca , Adulto Jovem
19.
J Clin Exp Dent ; 6(1): e41-6, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24596634

RESUMO

OBJECTIVES: This study aimed to evaluate the accuracy of Root ZX in determining working length in presence of normal saline, 0.2% chlorhexidine and 2.5% of sodium hypochlorite. MATERIAL AND METHODS: Sixty extracted, single rooted, single canal human teeth were used. Teeth were decoronated at CEJ and actual canal length determined. Then working length measurements were obtained with Root ZX in presence of normal saline 0.9%, 0.2% chlorhexidine and 2.5% NaOCl. The working length obtained with Root ZX were compared with actual canal length and subjected to statistical analysis. RESULTS: No statistical significant difference was found between actual canal length and Root ZX measurements in presence of normal saline and 0.2% chlorhexidine. Highly statistical difference was found between actual canal length and Root ZX measurements in presence of 2.5% of NaOCl, however all the measurements were within the clinically acceptable range of ±0.5mm. CONCLUSION: The accuracy of EL measurement of Root ZX within±0.5 mm of AL was consistently high in the presence of 0.2% chlorhexidine, normal saline and 2.5% sodium hypochlorite. CLINICAL SIGNIFICANCE: This study signifies the efficacy of ROOT ZX (Third generation apex locator) as a dependable aid in endodontic working length. Key words:Electronic apex locator, working length, root ZX accuracy, intracanal irrigating solutions.

20.
Hum Immunol ; 74(8): 1003-8, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23632061

RESUMO

Benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are two chronic conditions, very common in aged men, that have been associated to inflammatory process. Chemokines and their receptors are recognized as critical mediators of inflammatory responses, they regulate immune cell migration and are implicated in tumor pathogenesis. The impact of two chemokine receptor gene polymorphisms, CCR2-64I (rs1799864) and CCR5-Δ32 (rs333), was evaluated in BPH and PCa. 385 DNA samples (130 BPH, 136 PCa, 119 healthy control) were genotyped. The allele frequencies were similar among control, BPH and PCa groups. Median of serum PSA levels was different between groups: 0.79, 1.45 and 6.91 ng/mL in control, BPH and PCa groups, respectively (all p<0.001). The prostate volume median was 20.00 cm(3) in the control group, thus, lower than BPH (35.35 cm(3)) and PCa (35.80 cm(3)) (both p<0.001), nevertheless no statistical significant difference was observed between BPH and PCa patients (p=0.172). Remarkably, CCR2-64I was a protective factor to PCa when compared with BPH (OR=0.550; 95%CI=0.311-0.975), although the statistically significant difference was lost after correction for multiple comparisons. No significant associations of CCR5-Δ32 variant were observed with BPH, PCa or PCa clinicopathologic status. Our data suggest the influence of CCR2-64I variant in the development of prostate cancer.


Assuntos
Polimorfismo Genético , Hiperplasia Prostática/genética , Neoplasias da Próstata/genética , Receptores CCR2/genética , Receptores CCR5/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Estudos de Casos e Controles , Frequência do Gene , Genótipo , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Razão de Chances , Neoplasias da Próstata/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA