Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Cureus ; 15(11): e48838, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38106792

RESUMO

Background Guided bone regeneration (GBR) is an often-used technique to aid the successful placement of dental implants in sites with deficient bone. The search for the ideal GBR membrane with bioactive components improving the regenerative outcomes is still on. In this study, a novel composite GBR membrane was developed using selenium-doped bio-glass, collagen, and gelatin. It was further characterized for surface, chemical, biocompatibility, and antibacterial properties. Methodology Selenium-doped bio-glass was prepared using the sol-gel method. The membrane was fabricated using an equal ratio of collagen and gelatin mixed with 1% selenium-doped bio-glass. The solution was poured to obtain a thin layer of the material which was lyophilized to obtain the final GBR membrane. The membrane was analyzed with scanning electron microscopy, energy dispersive X-ray (EDX) analysis, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), zebrafish cytotoxicity test, and antibacterial assay. Results The membrane revealed good surface roughness with lamellar and fibrillar arrangement with a minute granular surface ideal for cell attachment and proliferation. The EDX analysis revealed the presence of carbon, oxygen, and nitrogen as predominant components with trace amounts of calcium, phosphorus, silica, and selenium. Fourier transform infrared spectroscopy analysis also proved the presence of collagen, gelatin, and bio-glass. The membrane revealed excellent biocompatibility with zebrafish growth at a normal rate with 90% viability maintained at 48, 72, and 96 hours and 95% viability at 120 hours. It also exhibited excellent antibacterial activity against Staphylococcus aureus and Escherichia coli with minimal growth of bacterial colonies. Conclusion The developed novel selenium bio-glass collagen and gelatin composite scaffold has a good surface and antibacterial properties along with excellent biocompatibility. Further cell line and in vivo studies should be conducted to explore its role in bone regeneration.

2.
Biochemistry ; 61(22): 2546-2559, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36314731

RESUMO

Preferential stabilization of G-quadruplex (G4) structures using small-molecule ligands has emerged as an effective approach to develop anticancer drugs. Herein, we report the synthesis of three indole-fused quindoline derivatives with varying lengths of side chains (InqEt1, InqEt2, and InqPr2) as selective ligands for promoter G4 structures. The ligands stabilize the parallel topology of c-MYC and c-KIT1 promoter G4 DNAs over telomeric and duplex DNAs, as evident from the circular dichroism melting and polymerase stop-assay experiments. The lead ligand, InqPr2, downregulates the gene expression of c-MYC and c-KIT in HeLa and HepG2 cells, respectively, leading to apoptotic cell death. Molecular modeling and dynamics studies support the 2:1 binding stoichiometry revealed from the Job plot analysis and show the ligand's structural features that enable the preferential binding to the parallel G4 structures over other topologies. Our studies show that indole-fused quindoline derivatives can be harnessed as new molecular scaffolds for selective targeting of parallel G4 topologies.


Assuntos
Quadruplex G , Quinolinas , Ligantes , Indóis/química
3.
J Inorg Biochem ; 234: 111870, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35660722

RESUMO

Binuclear Ru(II) polypyridyl complexes [Ru2(NN)4(BIPMB)]4+ (1-4), where N-N = 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen), dipyrido [3,2-d:2',3'-f] quinoxaline (dpq), and dipyrido[3,2-a:2',3'-c]phenazine (dppz), have been synthesized using suitable precursors and bridging ligand (BIPMB), where BIPMB = 3,3'-bis-{(imidazol-1-yl)-[4,5-f]-1,10-phenanthroline) methyl}-1,1'-biphenyl. The binding mode and affinity of complexes 1-4 with Calf Thymus DNA (CT-DNA) were determined by absorption and steady-state fluorescence spectroscopy. The decrease in viscosity of CT-DNA on sequential addition of these complexes indicated DNA condensation and the result was corroborated by circular dichroism (CD). The nanosized globular aggregates of CT-DNA induced by complexes 1-4 were observed by dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements. The gel electrophoretic mobility studies revealed the small orderly particles of supercoiled plasmid pBR322 DNA induced by these complexes. Additionally, the morphology and size of compact plasmid DNA condensates were studied by DLS and atomic force microscopy (AFM). The complexes were moderately cytotoxic against MCF-7 cells.


Assuntos
Compostos Organometálicos , Rutênio , Dicroísmo Circular , DNA/química , Clivagem do DNA , Compostos Organometálicos/química , Fenantrolinas/química , Rutênio/química
4.
Phys Chem Chem Phys ; 24(10): 6238-6255, 2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35229834

RESUMO

G-Quadruplexes (G4s) are four-stranded motifs formed by G-rich nucleic acid sequences. These structures harbor significant biological importance as they are involved in telomere maintenance, transcription, and translation. Owing to their dynamic and polymorphic nature, G4 structures relevant for therapeutic applications need to be stabilized by small-molecule ligands. Some of these ligands turn on fluorescence upon binding to G4 structures, which provides a powerful detection platform for G4 structures. Herein, we report the synthesis of fluorescent ligands based on the indolyl-quinolinium moiety to specifically stabilize G4 structures and sense DNA. CD titration and melting experiments have shown that the lead ligand induces the formation of parallel G4 with preferential stabilization of the c-MYC and c-KIT1 promoter G4s over the telomeric, h-RAS1 G4, and duplex DNA. Fluorimetric titration data revealed fluorescence enhancement when these ligands interact with G4 DNA structures. The fluorescence lifetime experiment of the ligand with different DNAs revealed three excited state lifetimes (ns), which indicates more than one binding site. MD studies showed that the ligand exhibits 3 : 1 stoichiometry of binding with c-MYC G4 DNA and revealed the unique structural features, which impart selectivity toward parallel topology. The ligand was found to have low cytotoxicity and exhibited preferential staining of DNA over RNA. Collectively, the results presented here offer avenues to harness indolyl-quinolinium scaffolds for sensing and selective stabilization of G4 structures.


Assuntos
Quadruplex G , DNA/química , Fluorescência , Ligantes , Telômero/metabolismo
5.
J Adv Pharm Technol Res ; 13(Suppl 1): S160-S163, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36643132

RESUMO

Carbonated beverages have side effects on oral health and general health. Flexural strength is a prime mechanical property of restorative material. The aim of this study is to know the effect of carbonated beverages on the flexural strength of composite restorative material. Two types of composites (Ivoclar and Restofill) were used as samples for comparative evaluation of flexural strength. The sample size is 10 where 5 of each type of composites are included. The obtained samples were immersed in carbonated beverages. One sample of each type was used as a control. After 24 h, the flexural strength of all the 10 samples was evaluated using the formula (3FL/2bd2), and the values were tabulated. Average values and graphs were done using SPSS software. The results showed the changes in flexural strength of both Ivoclar and Restofill materials when immersed in carbonated beverages. The mean value of all the samples was taken, and the standard deviation was calculated. After immersion in carbonated liquids, the mean value of Ivoclar and Restofill samples is 58.9 and 35.01, respectively. P = 0.718 (>0.05), which was not statistically significant. After immersion in Coke, the Restofill group exhibits more flexural strength than the Ivoclar group composite; however, the strength reduces when immersed in Sprite as compared to the Ivoclar group composite.

6.
Case Rep Infect Dis ; 2020: 6676163, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33457027

RESUMO

The use of BCG in immunotherapy for bladder cancer has been in practice for over 40 years. However, uncommon, serious complications can occur with the therapy. Here, we present a case of vertebral osteomyelitis secondary to dissemination of BCG following immunotherapy, an exceedingly rare presentation of an already rare complication.

7.
Inorg Chem ; 57(13): 7524-7535, 2018 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-29893118

RESUMO

Two heteronuclear ruthenium(II)-platinum(II) complexes [Ru(bpy)2(BPIMBp)PtCl2]2+ (3) and [Ru(phen)2(BPIMBp)PtCl2]2+ (4), where bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline, and BPIMBp = 1,4'-bis[(2-pyridin-2-yl)-1H-imidazol-1-ylmethyl]-1,1'-biphenyl, have been designed and synthesized from their mononuclear precursors [Ru(bpy)2(BPIMBp)]2+ (1) and [Ru(phen)2(BPIMBp)]2+ (2) as multitarget molecules for Alzheimer's disease (AD). The inclusion of the cis-PtCl2 moiety facilitates the covalent interaction of Ru(II) polypyridyl complexes with amyloid ß (Aß) peptide. These multifunctional complexes act as inhibitors of acetylcholinesterase (AChE), Aß aggregation, and Cu-induced oxidative stress and protect neuronal cells against Aß-toxicity. The study highlights the design of metal based anti-Alzheimer's disease (AD) systems.

8.
Chemistry ; 22(44): 15760-15771, 2016 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-27618785

RESUMO

A series of binuclear ruthenium(II)-polypyridyl complexes of the type [Ru2 (N-N)4 (BPIMBp)]4+ , in which N-N is 2,2'-bipyridine (bpy; 1), 1,10-phenanthroline (phen; 2), dipyrido[3,2-d:2',3-f] quinoxaline (dpq; 3), dipyrido[3,2-a:2',3'-c] phenanzine (dppz; 4), and 1,4'-bis[(2-pyridin-2-yl)-1H-imidazol-1-yl)methyl]-1,1'-biphenyl (BPIMBp) is a bridging ligand, have been synthesized and characterized. These complexes are charged (4+) cations and flexible due to the -CH2 group of the bridging ligand and possess terminal ligands with variable intercalative abilities. The interaction of complexes 1-4 with calf thymus DNA (CT-DNA) was explored by using UV/Vis absorption spectroscopy, steady-state emission, emission quenching with K4 [Fe(CN)6 ], ethidium bromide displacement assay, Hoechst displacement assay, and viscosity measurements and revealed a groove-binding mode for all the complexes through a spacer and an intercalative mode for complexes 3 and 4. A decrease in the viscosity of DNA revealed bending and coiling of DNA, an initial step toward aggregation. Interestingly, a distinctive honeycomb-like ordered assembly of the DNA-complex species was visualized by fluorescence microscopy in the solution state. The use of SEM and AFM confirmed the disordered self-organization of the DNA-complex adduct on evaporation of the solvent. The small orderly nanosized DNA aggregates were confirmed by means of circular dichroism, dynamic light scattering (DLS), and TEM. These complexes are moderately cytotoxic against three different cell lines, namely, MCF-7, HeLa, and HL-60.


Assuntos
2,2'-Dipiridil/química , Complexos de Coordenação/química , DNA/química , Fenantrolinas/química , Rutênio/química , Animais , Bovinos , Dicroísmo Circular , DNA/metabolismo , Células HeLa , Humanos , Ligantes , Estrutura Molecular , Viscosidade
9.
Chaos ; 26(6): 063113, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27368778

RESUMO

In this paper, transverse vibrations of an electrostatically actuated thin flexible cantilever perturbed by low-speed air flow are studied using both experiments and numerical modeling. In the experiments, the dynamic characteristics of the cantilever are studied by supplying a DC voltage with an AC component for electrostatic forcing and a constant uniform air flow around the cantilever system for aerodynamic forcing. A range of control parameters leading to stable vibrations are established using a dimensionless operating parameter that is the ratio of the induced and the free stream velocities. Numerical results are validated with experimental data. Assuming the amplitude of vibrations are small, then a non-linear dynamic Euler-Bernoulli beam equation with viscous damping and gravitational effects is used to model the equation of motion. Aerodynamic forcing is modelled as a temporally sinusoidal and uniform force acting perpendicular to the beam length. The forcing amplitude is found to be proportional to the square of the air flow velocity. Numerical results strongly agree with the experiments predicting accurate vibration amplitude, displacement frequency, and quasi-periodic displacement of the cantilever tip.

10.
J Oral Maxillofac Pathol ; 20(1): 111-4, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27194872

RESUMO

Prion diseases were first discovered by Stanley B. Prusiner who defined prions as infectious, transmissible proteinaceous particles that lack nucleic acid and are composed exclusively of a modified isoform of the noninfectious cellular prion protein (PrPC). These are incurable neurodegenerative conditions affecting both animals and humans. They may be sporadic, infectious or inherited in origin. Human prion diseases include Creutzfeldt-Jakob desease (CJD), Gerstmann- Straussler-Scheinker disease, Kuru and Fatal familial insomnia. Prions resist the conventional sterilization procedures and hence the dentists must be aware of such diseases so as to opt standard methods of infection control and decontamination for such infectious agents. This review article divulge the dentists with a brief overview of the characteristics of prions, the risk of transmission and the implications for infection control in dentist.

11.
J Indian Soc Pedod Prev Dent ; 34(1): 48-54, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26838148

RESUMO

BACKGROUND: Determining the relative risk of cleft lip and palate (CL[P]) on the basis of lip prints and dermatoglyphics as genetic background may be useful for genetic counseling, and the development of future preventive measures. AIMS AND OBJECTIVES: (1) To analyze the various pattern types of lip prints and dermatoglyphics in parents of CL(P) children and to detect if any specific type can be contemplated as a genetic marker in the transmission of CL(P). (2) To compare these patterns with that of parents of unaffected children. MATERIALS AND METHODS: 31 parents of children with CL(P) as a study group, and 31 parents of unaffected children as control group were included. Lip prints and finger prints were collected from all subjects and analysis of both patterns was carried out followed by a comparison of the patterns of unaffected parents with the controls statistically. RESULTS: Among the mothers of the study group, type O followed by type IIa lip patterns were found to be significantly higher in upper and lower lips, and in fathers type IIa followed by type O were significantly higher. In the control group, type IIb followed by type III were higher in both fathers and mothers. Dermatoglyphic analysis of palm and finger prints revealed no significant difference in the pattern types and total ridge counts, but the Atd angle asymmetry was found to be significant between study and control group. CONCLUSION: Types IIa and O lip patterns, asymmetry of Atd angles can be considered as genetic markers for the transmission of CL(P) deformity to offsprings.


Assuntos
Fenda Labial/genética , Fissura Palatina/genética , Dermatoglifia , Marcadores Genéticos , Pais , Adulto , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Fenótipo , Valor Preditivo dos Testes , Medição de Risco
12.
Dalton Trans ; 45(7): 3003-12, 2016 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-26758215

RESUMO

Mixed-ligand Cu(ii) complexes of the type [Cu(doxycycline)(L)(H2O)2](NO3)2, where doxycycline = [4-(dimethylamino)-3,5,10,12,12a-pentahydroxy-6-methyl-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide] and L = 2,2'-bipyridine (bpy, 1), 1,10-phenanthroline (phen, 2), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq, 3) and dipyrido[3,2-a:2',3'-c]phenazine (dppz, 4) have been synthesised and characterised by structural, analytical, and spectral methods. The single-crystal X-ray structures of 1 and 2 exhibited two different geometries, distorted square-pyramidal and octahedral respectively as well as different coordination modes of doxycycline. Complexes 2-4 exhibit prominent plasmid DNA cleavage at significantly low concentrations probably by an oxidative mechanism. Matrix Metalloproteinase (MMP-2) inhibition studies revealed that all complexes inhibit MMP-2 similar to doxycycline which is a well-known MMP inhibitor with 3 being the most potent. IC50 values of doxycycline and 1-4 against MCF-7 (human breast cancer) and HeLa cell lines were almost equal in which 3 showed the highest efficiency (IC50 = 0.46 ± 0.05 µM), being consistent with its increased MMP inhibition potency. The antimalarial activities of these complexes against the chloroquine-sensitive Plasmodium falciparum NF54 and chloroquine-resistant Plasmodium falciparum Dd2 strains reveal that complex 3 exhibited a higher activity than artesunate drug against the chloroquine-resistant Dd2 strain.


Assuntos
Antimaláricos/química , Antineoplásicos/química , Complexos de Coordenação/química , Cobre/química , Doxiciclina/química , Inibidores de Metaloproteinases de Matriz/química , Piridinas/química , Antimaláricos/síntese química , Antimaláricos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/farmacologia , Cristalografia por Raios X , Clivagem do DNA/efeitos dos fármacos , Células HeLa , Humanos , Ligantes , Inibidores de Metaloproteinases de Matriz/síntese química , Inibidores de Metaloproteinases de Matriz/farmacologia , Estrutura Molecular , Testes de Sensibilidade Parasitária , Plasmodium falciparum/efeitos dos fármacos
13.
Int J Phytoremediation ; 18(8): 747-53, 2016 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-26587690

RESUMO

Phycoremediation ability of microalgae namely Oscillatoria acuminate and Phormidium irrigum were validated against the heavy metals from tannery effluent of Ranipet industrial area. The microalgae species were cultured in media containing tannery effluent in two different volumes and the parameters like specific growth rate, protein content and antioxidant enzyme activities were estimated. FTIR spectroscopy was carried out to know the sorption sites interaction. The antioxidant enzymes namely superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) contents were increased in microalgae species indicating the free radical scavenging mechanism under heavy metal stress. SOD activity was 0.502 and 0.378 units/gram fresh weight, CAT activity was 1.36 and 0.256 units/gram fresh weight, GSH activity was 1.286 and 1.232 units/gram fresh weight respectively in the effluent treated microalgae species. Bio sorption efficiency for Oscillatoria acuminate and Phormidium irrigum was 90% and 80% respectively. FTIR analysis revealed the interaction of microalgae species with chemical groups present in the tannery effluent. From the results, the microalgae Oscillatoria acuminate possess high antioxidant activity and bio sorption efficiency when compared to Phormidium irrigum and hence considered useful in treating heavy metals contaminated effluents.


Assuntos
Biodegradação Ambiental , Cianobactérias/metabolismo , Resíduos Industriais , Microalgas/metabolismo , Oscillatoria/metabolismo , Curtume , Poluentes Químicos da Água/metabolismo , Antioxidantes/metabolismo , Catalase/metabolismo , Metais Pesados/metabolismo , Superóxido Dismutase/metabolismo
14.
J Affect Disord ; 174: 367-71, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25545603

RESUMO

BACKGROUND: Limited numbers of studies have examined the prevalence of OCD systematically in consecutively sampled adult bipolar disorder type I (BD-I) patients. We examined the frequency of OCD in a large number (n=396) of consecutively hospitalized patients with BD-I and identified socio-demographic and clinical correlates of BD-I with and without OCD. METHOD: BD-I patients (n=396) were assessed using the Mini International Neuropsychiatric Interview for Bipolar Disorder Studies, the Structured clinical interview for (Axis II) DSM-IV, the Family interview for genetic studies, the Yale-Brown Obsessive-Compulsive Scale, the Young Mania Rating Scale, the Hamilton Rating Scale for Depression, the Global Assessment of Functioning (GAF) and the Clinical Global Impression scale. Patients with and without OCD were compared in terms of various socio-demographic and clinical variables. RESULTS: Thirty (7.6%) of the 396 inpatients studied had OCD and 15 (3.8%) had subclinical OCD. BD-OCD group had significantly lower GAF scores, higher rates of unemployment, and lower incidence of psychotic symptoms. In addition, BD-OCD group had higher rates of comorbid social anxiety and anxious avoidant personality disorder (AAPD) and OCD in first-degree relatives. Those with clinical and subclinical OCD did not differ on functioning and severity measures. LIMITATIONS: Retrospective design and recruitment of patients from inpatient services of a tertiary psychiatric hospital. CONCLUSION: OCD is not an uncommon comorbid disorder in BD-I and appears to be associated with greater functional disability. BD-I with comorbid OCD is associated with greater family history of OCD, comorbidities of social phobia and AAPD and less of psychotic symptoms.


Assuntos
Transtorno Bipolar/epidemiologia , Transtornos Mentais/epidemiologia , Transtorno Obsessivo-Compulsivo/epidemiologia , Adulto , Transtorno Bipolar/psicologia , Estudos de Casos e Controles , Comorbidade , Demografia , Manual Diagnóstico e Estatístico de Transtornos Mentais , Feminino , Humanos , Índia/epidemiologia , Masculino , Transtorno Obsessivo-Compulsivo/psicologia , Prevalência , Estudos Retrospectivos , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA