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1.
Indian J Dent Res ; 30(4): 595-599, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31745059

RESUMO

Background: DNA analysis has a key role in forensic dentistry. However, techniques of DNA extraction and analysis are far from the reach of majority of medical professionals owing to its expensive set up. Aim: The present study was aimed at formulating a crude method of extracting DNA from human buccal mucosa cells using materials commonly available in the laboratory so that the medical professionals could get more exposure to molecular biology techniques. The objectives were to identify the DNA and to assess its purity. Methods: Buccal mucosa cells from 10 healthy volunteers were taken for DNA extraction following the protocol of cell lysis, purification, and precipitation. DNA was identified using standardized techniques like Diphenylamine test and its purity was assessed using a spectrophotometer. A gel electrophoresis apparatus was also constructed using readily available materials. Results: DNA was extracted from human buccal mucosa cells using a crude method. The standardized tests confirmed the presence of DNA contaminated with proteins. The locally made Gel electrophoresis model exhibited a faint halo around the wells instead of DNA bands. Conclusion: DNA extraction from human buccal mucosa cells was made possible using locally available materials and a crude method, but it was not of high purity.


Assuntos
DNA , Mucosa Bucal , Humanos
2.
Chem Commun (Camb) ; 55(92): 13932-13935, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31686058

RESUMO

In this work, a bipedal DNA walker was employed to mediate an efficient enzyme-free exponential isothermal DNA signal amplification. On the basis of the bipedal DNA walker mediated enzyme-free exponential isothermal signal amplification, an electrochemiluminescence (ECL) biosensor was constructed for sensitive and rapid detection of microRNA (miRNA) with a limit of detection down to 0.24 fM and requiring less than 40 min.


Assuntos
Técnicas Biossensoriais/métodos , DNA/química , MicroRNAs/análise , Linhagem Celular Tumoral , Complexos de Coordenação/química , DNA/metabolismo , Humanos , Limite de Detecção , Medições Luminescentes , Nanopartículas Metálicas/química , Hibridização de Ácido Nucleico , Rutênio/química , Titânio/química
3.
J Chem Phys ; 151(16): 164902, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31675856

RESUMO

Most of the anticancer drugs bind to double-stranded DNA (dsDNA) by intercalative-binding mode. Although experimental studies have become available recently, a molecular-level understanding of the interactions between the drug and dsDNA that lead to the stability of the intercalated drug is lacking. Of particular interest are the modifications of the mechanical properties of dsDNA observed in experiments. The latter could affect many biological functions, such as DNA transcription and replication. Here, we probe, via all-atom molecular dynamics (MD) simulations, the change in the mechanical properties of intercalated drug-DNA complexes for two intercalators, daunomycin and ethidium. We find that, upon drug intercalation, the stretch modulus of DNA increases significantly, whereas its persistence length and bending modulus decrease. Steered MD simulations reveal that it requires higher forces to stretch the intercalated dsDNA complexes than the normal dsDNA. Adopting various pulling protocols to study force-induced DNA melting, we find that the dissociation of dsDNA becomes difficult in the presence of intercalators. The results obtained here provide a plausible mechanism of function of the anticancer drugs, i.e., via altering the mechanical properties of DNA. We also discuss long-time consequences of using these drugs, which require further in vivo investigations.


Assuntos
Antineoplásicos/química , DNA/química , Substâncias Intercalantes/química , Simulação de Dinâmica Molecular , Conformação de Ácido Nucleico
4.
Zootaxa ; 4560(2): zootaxa.4560.2.11, 2019 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31716588

RESUMO

Sperchon fuxiensis Zhang, 2017 was published as a new species based on females alone. Two males of Sperchon were found in the same locality during our recent collection. The males resemble S. fuxiensis female in the integument pattern, excretory pore and the palps shape, but the chitinous plates of both dorsum and venter differ greatly. The males were paired with the female of S. fuxiensis using DNA barcoding, revealing unusual sexual dimorphism in the species. Descriptions and illustrations of the male of S. fuxiensis are given in the present study. Species identification based on the full-length DNA barcoding (658bp) of COI in water mites is also discussed.


Assuntos
Ácaros , Animais , DNA , Código de Barras de DNA Taxonômico , Feminino , Masculino , Ácaros/genética , Caracteres Sexuais , Água
5.
Adv Exp Med Biol ; 1174: 331-370, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31713205

RESUMO

DNA nanotechnology has revolutionised the capabilities to shape and control three-dimensional structures at the nanometre scale. Designer sensors, nanopores and ion-channels built from DNA have great potential for both cross-disciplinary research and applications. Here, we introduce the concept of structural DNA nanotechnology, including DNA origami, and give an overview of the work flow from design to assembly, characterisation and application of DNA-based functional systems. Chemical functionalisation of DNA has opened up pathways to transform static DNA structures into dynamic nanomechanical sensors. We further introduce nanopore sensing as a powerful label-free single-molecule technique and discuss how it can benefit from DNA nanotechnology. Especially exciting is the possibility to create membrane-inserted DNA nanochannels that mimic their protein-based natural counterparts in form and function. In this chapter we review the status quo of DNA sensors, nanopores and ion channels, highlighting opportunities and challenges for their future development.


Assuntos
Técnicas Biossensoriais , DNA , Nanoporos , Nanotecnologia , Técnicas Biossensoriais/tendências , DNA/química , Canais Iônicos/química , Nanotecnologia/tendências
7.
Zootaxa ; 4658(1): zootaxa.4658.1.4, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31716758

RESUMO

This study describes two new species of earthworms belonging to the genus Amynthas (Oligochaeta: Megascolecidae) from central Taiwan. They are named Amynthas luridus sp. nov. and Amynthas ruiyenensis sp. nov. Both species are octothecal with the former found at elevations of 1500-2300 m and the latter at an elevation of 2200 m from the Central Mountain Range. In addition, DNA barcodes are made available for the first time for the following species: Amynthas catenus Tsai et al., 2001, Amynthas exiguus aquilonius Tsai et al., 2001, Amynthas proasacceus Tsai et al., 2001, Amynthas hohuanmontis Tsai et al., 2002, Amynthas tessellatus Shen et al., 2002, Amynthas fenestrus Shen et al., 2003, Amynthas tantulus Shen et al., 2003, and Amynthas uvaglandularis Shen et al., 2003. Furthermore, Amynthas exiguus ssp. aquilonius Tsai et al., 2001 distributed at elevations of 2200-3000 m in the Central Mountain Range is elevated to species level, as A. aquilonius Tsai et al., 2001. The highest altitude record so far for the exotic Eukerria saltensis (Beddard, 1895) in Taiwan, 2200 m above sea level, is documented. Moreover, some recent assignments of species to Amynthas and Metaphire and synonymies of names are critically discussed. It is argued that idiosyncratic genus concepts, inadequate species comparisons, and unexplained synonymies should be avoided. A hitherto undetected and possibly monophyletic species group of mainly Korean Amynthas species in the A. tokioensis-group is indicated, characterized by numerous genital papillae around each spermathecal pore and male porophore, large ampullae, long diverticula, large prostate glands, and manicate intestinal caeca. The names A. bimaculata, A. silvatica and A. surcata (Ishizuka, 1999), as well as A. odaesanensis, A. righii, A. fasciiformis, and A. sanchongensis Hong James, 2001, previously declared as junior synonyms of A. tappensis (Ohfuchi, 1935), are revalidated.


Assuntos
Asteraceae , Oligoquetos , Animais , DNA , Masculino , Taiwan
8.
Zootaxa ; 4656(1): zootaxa.4656.1.6, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31716841

RESUMO

We describe a new frog species of the Spinomantis bertini species complex based on congruent genetic evidence from mitochondrial and nuclear DNA sequences as well as minor morphological differences. A molecular phylogeny derived from the mitochondrial 16S rRNA gene revealed that Spinomantis mirus sp. nov. is sister to a clade containing the other two described species of the species complex, S. bertini and S. beckei, but strongly differentiated from these two species by 8.1-9.8% pairwise distances in this gene. DNA sequences from two nuclear genes revealed that S. mirus sp. nov. shares no alleles with these two species. Phenotypically, S. mirus sp. nov. differs from the other species of the complex by its larger size and some aspects of its coloration, including clear mottling on the flanks, tri-color banding on the legs, and distinct brown dots on the dorsum. The new species is so far only known from Pic d'Ivohibe Special Reserve. Its distribution thus appears to not overlap with those of the other two species, which as far as known are restricted to the Andohahela Massif in the extreme South-East of Madagascar, at a distance of about 250 km from Ivohibe.


Assuntos
Anuros , DNA , Animais , Madagáscar , Filogenia , RNA Ribossômico 16S
9.
Zootaxa ; 4576(1): zootaxa.4576.1.4, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31715775

RESUMO

Eleven (two known and nine new) species of the subgenus Stegana (Steganina) from China are described or redescribed: S. (S.) longifibula Takada, 1968, S. (S.) toyaensis Okada Sidorenko, 1992, S. (S.) biflava sp. nov., S. (S.) flavivittata sp. nov., S. (S.) hirtifoliacea sp. nov., S. (S.) latitabula sp. nov., S. (S.) panda sp. nov., S. (S.) pinguifoliacea sp. nov., S. (S.) spatulata sp. nov., S. (S.) stachydifolia sp. nov. and S. (S.) unguiculata sp. nov.; they are assigned into the coleoptrata, ornatipes and undulata species groups, respectively. A total of 130 DNA sequences of partial mitochondrial cytochrome c oxidase subunit I (mtCOI) gene of 38 species (including the 11 species) of above-mentioned three groups are newly obtained in this study. These sequences and other available barcoding sequences of the three groups are involved in a molecular analysis using neighbor-joining (NJ) method, in order to assess the availability of DNA barcoding for delimiting the Steganina species. The result indicates that all the sampled Steganina morphospecies within the three groups are monophyletic.


Assuntos
Drosophilidae , Animais , China , DNA , Código de Barras de DNA Taxonômico , Drosophilidae/genética , Filogenia
10.
Zootaxa ; 4651(3): zootaxa.4651.3.12, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31716906

RESUMO

Stenelmis koreana Satô, 1978 (Coleoptera: Elmidae) is here recorded for the first time from Kyrgyzstan and Western Siberia. It was hitherto thought to be confined to Korea and the Russian Far East. The identification of a specimen from Kyrgyzstan was confirmed by DNA-sequencing after comparison with two sequences of S. koreana from Korea. The COI haplotype of the Kyrgyzstan specimen has very low sequence divergence (0.53 % or 0.0053 uncorrected p-distance) with respect to the sequences of the Korean specimens, which is within the standard intraspecific sequence divergence for COI in beetles.


Assuntos
Besouros , Animais , Besouros/genética , DNA , Extremo Oriente , Quirguistão , Filogenia , República da Coreia , Federação Russa , Sibéria
11.
Zootaxa ; 4691(2): zootaxa.4691.2.3, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31719402

RESUMO

We diagnose and describe two Songthela and one Vinathela species of the primitively segmented spiders, Liphistiidae, as new to science based on morphological characters and molecular data: Songthela pyriformis sp. nov. (male, female), Songthela shuyuan sp. nov. (male, female), Vinathela nenglianggu sp. nov. (male, female), which were collected at Mt Yuelu in Changsha, Hunan Province, China. To facilitate future identification of our species, we also provide the GenBank accession numbers of the DNA barcode gene, cytochrome c oxidase subunit I (COI) for all type specimens and the evidence of genetic distances based on COI for three new species.


Assuntos
Aranhas , Animais , China , DNA , Feminino , Masculino
12.
Chem Soc Rev ; 48(23): 5564-5595, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31670726

RESUMO

The design and applications of some inorganic two-dimensional (2D) nanomaterials such as graphene, graphyne, and borophene have been widely studied in recent years. Meanwhile, it has been noticed that self-assembling two-dimensional organic biomaterials (2DOBMs) including films, membranes, nanosheets, nanoribbons, grids, arrays, and lattices based on various biomolecules also exhibited promising structures, functions, and applications. The in-depth studies on the self-assembly formation, structural and functional tailoring of 2DOBMs open new avenues for the next generation of novel nanomaterials with adjustable structure and functions, which would further promote the applications of 2DOBMs in materials science, nanodevices, energy and environmental science, biomedicine, tissue engineering, and analytical science. In this review, we summarize important information on the basic principles to fabricate self-assembling 2DOBMs based on peptides, proteins, DNA, RNA, viruses, and other biopolymers. The potential strategies and techniques for tailoring and controlling the structures and functions of 2DOBMs are presented and discussed further. The function-specific biomedical applications of 2DOBMs in biosensors, biomimetic mineralization, cell growth, drug/gene delivery, and bioimaging are also highlighted.


Assuntos
Materiais Biocompatíveis/química , Animais , Técnicas Biossensoriais/métodos , DNA/química , Portadores de Fármacos/química , Nanoestruturas/química , Imagem Óptica , Polímeros/química , Proteínas/química , Engenharia Tecidual
13.
F1000Res ; 82019.
Artigo em Inglês | MEDLINE | ID: mdl-31602296

RESUMO

DNA topoisomerases are enzymes that catalyze changes in the torsional and flexural strain of DNA molecules. Earlier studies implicated these enzymes in a variety of processes in both prokaryotes and eukaryotes, including DNA replication, transcription, recombination, and chromosome segregation. Studies performed over the past 3 years have provided new insight into the roles of various topoisomerases in maintaining eukaryotic chromosome structure and facilitating the decatenation of daughter chromosomes at cell division. In addition, recent studies have demonstrated that the incorporation of ribonucleotides into DNA results in trapping of topoisomerase I (TOP1)-DNA covalent complexes during aborted ribonucleotide removal. Importantly, such trapped TOP1-DNA covalent complexes, formed either during ribonucleotide removal or as a consequence of drug action, activate several repair processes, including processes involving the recently described nuclear proteases SPARTAN and GCNA-1. A variety of new TOP1 inhibitors and formulations, including antibody-drug conjugates and PEGylated complexes, exert their anticancer effects by also trapping these TOP1-DNA covalent complexes. Here we review recent developments and identify further questions raised by these new findings.


Assuntos
DNA Topoisomerases/fisiologia , Neoplasias , DNA , Dano ao DNA , Replicação do DNA , Humanos
14.
Postepy Biochem ; 65(2): 143-152, 2019 06 06.
Artigo em Polonês | MEDLINE | ID: mdl-31642653

RESUMO

High replication fidelity, understood as the DNA polymerases' ability to select nucleotides with both correct base and sugar, is of critical importance for maintaining the genetic stability. Due to the fact that the cellular levels of ribonucleotides are much higher than the concentrations of deoxyribonucleotides, replicative polymerases are able to incorporate ribonucleotides with up to 1000-fold higher frequency than mismatched deoxyribonucleotides. The ability to discriminate against ribonucleotides by the DNA polymerases relies on the steric gate residue in the enzyme's catalytic centre. Despite the fact that ribonucleotides are the most abundantly inserted incorrect nucleotides in DNA, they are not observed in properly functioning cells. The major pathway responsible for the recognition and removal of ribonucleotides from DNA is called Ribonucleotide Excision Repair. The impairment of ribonucleotide removal pathways can cause increased mutation rate, replication stress, DNA breakage, problems with transcription, chromatin structure maintenance, genetic disorders and cell death. In spite of that, ribonucleotide incorporation into DNA may have some positive biological impact, stimulating mismatch repair and non-homologous end joining.


Assuntos
Reparo do DNA , DNA Polimerase Dirigida por DNA/metabolismo , DNA/química , DNA/metabolismo , Instabilidade Genômica , Ribonucleotídeos/metabolismo , DNA/genética , Replicação do DNA , Desoxirribonucleotídeos/química , Desoxirribonucleotídeos/metabolismo , Ribonucleotídeos/química
15.
Chem Commun (Camb) ; 55(83): 12428-12446, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31576822

RESUMO

DNA is an attractive molecular building block to construct nanoscale structures for a variety of applications. In addition to their structure and function, modification the DNA nanostructures by other molecules opens almost unlimited possibilities for producing functional DNA-based architectures. Among the molecules to functionalize DNA nanostructures, proteins are one of the most attractive candidates due to their vast functional variations. DNA nanostructures loaded with various types of proteins hold promise for applications in the life and material sciences. When loading proteins of interest on DNA nanostructures, the nanostructures by themselves act as scaffolds to specifically control the location and number of protein molecules. The methods to arrange proteins of interest on DNA scaffolds at high yields while retaining their activity are still the most demanding task in constructing usable protein-modified DNA nanostructures. Here, we provide an overview of the existing methods applied for assembling proteins of interest on DNA scaffolds. The assembling methods were categorized into two main classes, noncovalent and covalent conjugation, with both showing pros and cons. The recent advance of DNA-binding adaptor mediated assembly of proteins on the DNA scaffolds is highlighted and discussed in connection with the future perspectives of protein assembled DNA nanoarchitectures.


Assuntos
DNA/metabolismo , Proteínas/metabolismo , DNA/química , Nanoestruturas/química , Proteínas/química
16.
Chem Commun (Camb) ; 55(86): 12980-12983, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31603440

RESUMO

Nuclear factor kappa B p50 (NF-κB p50) induces various biological processes. In this study, a highly selective and sensitive electrochemiluminescence (ECL) biosensor for the detection of NF-κB p50 has been developed, which combines the high selectivity of the proximity hybridization assay (PHA) with the high efficiency of the hybridization chain reaction (HCR).


Assuntos
Técnicas Biossensoriais/métodos , Subunidade p50 de NF-kappa B/análise , DNA/química , Técnicas Eletroquímicas , Eletrodos , Humanos , Medições Luminescentes , Técnicas de Amplificação de Ácido Nucleico , Hibridização de Ácido Nucleico
17.
Chem Commun (Camb) ; 55(87): 13082-13084, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31608901

RESUMO

Herein, a photoelectrochemical biosensor was successfully constructed on the basis of a sensitization strategy of doxorubicin sensitized graphitic carbon nitride for the ultrasensitive detection of microRNA-141 with the assistance of a target-activated enzyme-free DNA walker.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Técnicas Biossensoriais , DNA/efeitos dos fármacos , Doxorrubicina/farmacologia , Técnicas Eletroquímicas , Grafite/química , MicroRNAs/análise , Compostos de Nitrogênio/química , Antibióticos Antineoplásicos/química , Doxorrubicina/química , Processos Fotoquímicos
18.
Chem Commun (Camb) ; 55(89): 13414-13417, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31638106

RESUMO

Herein, by anchoring cholesterol-labelled DNA probes to silicon-supported lipid bilayers via cholesterol-lipid interaction, a dynamic three-dimensional (3D) DNA nanostructure could be facilely assembled, which is applied as a microRNA (miRNA)-induced self-powered 3D DNA nanomachine with high movement efficiency. Once the self-powered 3D DNA nanomachine is triggered by target miRNA, it achieves autonomous operation without external addition of fuel DNA strands or protein enzymes. Impressively, the biocompatible lipid bilayers not only preserve the biological character of the DNA probes, but also improve the movement efficiency of the DNA nanomachine, which directly solves the key challenge of the steric barrier effect of traditional rigid surfaces (Au or silicon) for DNA probe diffusion. As a proof of concept, our proposed DNA nanomachine is successfully applied in rapid and sensitive detection of miRNAs, which gives a new idea for the construction of highly efficient DNA nanomachines for biosensing and clinic diagnosis.


Assuntos
Técnicas Biossensoriais , DNA/química , Bicamadas Lipídicas/química , Nanoestruturas/química , Silício/química , Colesterol/química , Sondas de DNA/química , Técnicas e Procedimentos Diagnósticos , Células HeLa , Humanos , Células MCF-7 , MicroRNAs/análise , MicroRNAs/química , Microscopia Confocal , Imagem Óptica , Tamanho da Partícula , Propriedades de Superfície
19.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(5): 1633-1640, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31607325

RESUMO

OBJECTIVE: To investigate the effects of cytomegalovirus (CMV) DNA load on immune reconstitution and clinical outcomes of patients after unrelated cord blood transplantation (UCBT). METHODS: Eight-color flow cytometry was used to dynamically monitor the changes of peripheral blood lymphocyte subsets of 41 patients at one year after UCBT, and 10 healthy volunteers were enroled as controls. Patients were divided into two groups according to the DNA load of CMV (DNA copies <1000/ml and DNA copies ≥1000/ml). Comparative analyse of the effect of CMV DNA load on lymphocyte subsets and transplantation outcomes were carried out after transplantation. RESULTS: The high CMV DNA load group showed a faster and expanded T cell reconstitution, and the differences between the two groups were statistically significant at one and nine months after transplantation (0.38×109 /L vs 0.25×109 /L, P=0.015 and 2.53×109 /L vs 1.36×109 /L, P=0.006, respectively). Further analysis of T cell subsets suggested that CD8+ T cells presented a higher and faster recovery in the high DNA load group, and the differences between the two groups were statistically significant at one and nine months after transplantation (0.20×109 /L vs 0.10×109 /L, P=0.038 and 1.62×109 /L vs 0.68×109 /L, P=0.003, respectively). In addition, there were no significant differences in levels of B cells, regulatory B cells and NK cells between the two groups. Outcomes after one- and a-half-year transplantation showed that there were no significant difference in relapse, non-relapse mortality and overall survival between the high and the low DNA load groups (7.7% vs 7.5%) (P=0.900) (15.4% vs 21.4%) (P=0.686) and (76.9% vs 78.6%) (P=0.889) respectively. CONCLUSION: The high CMV DNA load induces a faster and long-lasting expansion of T cells, mainly as the expansion of CD8+ T cells after UCBT. Besides, under the current pre-emptive treatment of CMV, the high CMV DNA load does not affect the early survival of patients with acute myeloid leukemia after UCBT.


Assuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical , Transplante de Células-Tronco Hematopoéticas , Reconstituição Imune , Linfócitos T CD8-Positivos , Citomegalovirus , DNA , Humanos
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