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1.
Trop Biomed ; 40(2): 152-159, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37650400

RESUMO

Antibiotics which once a boon in medicine and saved millions of lives are now facing an ever-growing menace of antibacterial resistance, which desperately needs new antibacterial drugs which are innovative in chemistry and mode of action. For many years, the world has turned to natural plants with antibacterial properties to combat antibiotic resistance. On that basis, we aimed to identify plants with antibacterial and antibiotic potentiating properties. Seventeen different extracts of 3 plants namely Burkillanthus malaccensis, Diospyros hasseltii and Cleisthanthus bracteosus were tested against multi-drug resistant Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Methicillinresistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA). Antibacterial activity of hexane, methanol and chloroform extracts of bark, seed, fruit, flesh and leaves from these plants were tested using, disk diffusion assay, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Antibiotic potentiating capabilities were tested using time-kill assay. B. malaccensis fruit chloroform extract showed the biggest zone of inhibition against MRSA (13.00±0.0 mm) but C. bracteosus bark methanol extract showed the biggest inhibition zone against MSSA (15.33±0.6 mm). Interestingly, bark methanol extract of C. bracteosus was active against MRSA (8.7±0.6 mm), MSSA (7.7±0.6 mm) (Gram-positive) and A. baumannii (7.7±0.6 mm) (Gram-negative). Overall, the leaf methanol and bark methanol extract of C. bracteosus warrants further investigation such as compound isolation and mechanism of action for validating its therapeutic use as antibiotic potentiator importantly against MRSA and A. baumannii.


Assuntos
Antibacterianos , Bactérias , Extratos Vegetais , Humanos , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Clorofórmio/farmacologia , Diospyros/química , Metanol/farmacologia , Extratos Vegetais/farmacologia , Rutaceae/química , Phyllanthus/química
2.
Tropical Biomedicine ; : 152-159, 2023.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-1006586

RESUMO

@#Antibiotics which once a boon in medicine and saved millions of lives are now facing an ever-growing menace of antibacterial resistance, which desperately needs new antibacterial drugs which are innovative in chemistry and mode of action. For many years, the world has turned to natural plants with antibacterial properties to combat antibiotic resistance. On that basis, we aimed to identify plants with antibacterial and antibiotic potentiating properties. Seventeen different extracts of 3 plants namely Burkillanthus malaccensis, Diospyros hasseltii and Cleisthanthus bracteosus were tested against multi-drug resistant Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Methicillinresistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA). Antibacterial activity of hexane, methanol and chloroform extracts of bark, seed, fruit, flesh and leaves from these plants were tested using, disk diffusion assay, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Antibiotic potentiating capabilities were tested using time-kill assay. B. malaccensis fruit chloroform extract showed the biggest zone of inhibition against MRSA (13.00±0.0 mm) but C. bracteosus bark methanol extract showed the biggest inhibition zone against MSSA (15.33±0.6 mm). Interestingly, bark methanol extract of C. bracteosus was active against MRSA (8.7±0.6 mm), MSSA (7.7±0.6 mm) (Gram-positive) and A. baumannii (7.7±0.6 mm) (Gram-negative). Overall, the leaf methanol and bark methanol extract of C. bracteosus warrants further investigation such as compound isolation and mechanism of action for validating its therapeutic use as antibiotic potentiator importantly against MRSA and A. baumannii.

3.
J Hosp Infect ; 102(1): 8-16, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30653999

RESUMO

BACKGROUND: ß-Lactamase resistance among certain Gram-negative bacteria has been associated with increased mortality, length of hospitalization, and hospital costs. AIM: To identify and critically appraise existing clinical prediction models of extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-EKP) infection or colonization. METHODS: Electronic databases, reference lists, and citations were searched from inception to April 2018. Papers were included in any language describing the development or validation, or both, of models and scores to predict the risk of ESBL-EKP infection or colonization. FINDINGS: In all, 1795 references were screened, of which four articles were included in the review. The included studies were carried out in different geographical locations with differing study designs, and inclusion and exclusion criteria. Most if not all studies lacked external validation and blinding of reviewers during the evaluation of the predictor variables and outcome. All studies excluded missing data and most studies did not report the number of patients excluded due to missing data. Fifteen predictors of infection or colonization with ESBL-EKP were identified. Commonly included predictors were previous antibiotic use, previous hospitalization, transfer from another healthcare facility, and previous procedures (urinary catheterization and invasive procedures). CONCLUSION: Due to limitations and variations in the study design, clinicians would have to take these differences into consideration when deciding on how to use these models in clinical practice. Due to lack of external validation, the generalizability of these models remains a question. Therefore, further external validation in local settings is needed to confirm the usefulness of these models in supporting decision-making.


Assuntos
Portador Sadio/epidemiologia , Portador Sadio/microbiologia , Técnicas de Apoio para a Decisão , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/microbiologia , Enterobacteriaceae/enzimologia , beta-Lactamases/análise , Idoso , Enterobacteriaceae/isolamento & purificação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
4.
J Gerontol Soc Work ; 59(7-8): 512-536, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27824306

RESUMO

This pilot project asked: How do ethnically diverse older adult residents of assisted living (AL) facilities in British Columbia (BC) experience quality of life? And, what role, if any, do organizational and physical environmental features play in influencing how quality of life is experienced? The study was conducted at three AL sites in BC: two ethnoculturally targeted and one nontargeted. Environmental audits at each site captured descriptive data on policies, fees, rules, staffing, meals, and activities, and the built environment of the AL building and neighborhood. Using a framework that understands the quality of life of older adults to be contingent on their capability to pursue 5 conceptual attributes-attachment, role, enjoyment, security, and control-we conducted 3 focus groups with residents (1 per site) and 6 interviews with staff (2 per site). Attributes were linked to the environmental features captured in the audits. All dimensions of the environment, especially organizational, influence tenants' capability to attain the attributes of quality of life, most importantly control. Although many tenants accept the trade-off between increased safety and diminished control that accompanies a move into AL, more could be done to minimize that loss. Social workers can advocate for the necessary multi-sectoral changes.


Assuntos
Moradias Assistidas/normas , Satisfação Pessoal , Qualidade de Vida/psicologia , Idoso , Idoso de 80 Anos ou mais , Atitude do Pessoal de Saúde , Colúmbia Britânica , Redes Comunitárias , Feminino , Grupos Focais , Humanos , Masculino , Autonomia Pessoal , Projetos Piloto , Gestão da Segurança
5.
Nanoscale ; 4(16): 5031-8, 2012 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-22766774

RESUMO

The ability to control the morphologies and spectral properties of organic low-dimensional nanomaterials is of paramount importance. The research reported herein demonstrates a template-free approach to tailored morphological and optical properties for a novel class of pseudoisocyanine (PIC)-based fluorescent organic nanoparticles derived from a group of uniform materials based on organic salts (GUMBOS). The synthesized nanoscale PIC-based particles (termed nanoGUMBOS), [PIC][NTf(2)] and [PIC][BETI], exhibit interesting adaptability as a function of the associated anion. The diamond-shaped nanostructures of [PIC][NTf(2)] and [PIC][BETI] nanorods exhibit enhanced fluorescence quantum yields relative to the parent compound, [PIC][I]. As supported by fluorescence lifetime measurements, these enhanced spectral properties can be attributed to differences in molecular self-assembly ordering (e.g., H- vs. J-aggregation) and restricted molecular rotation leading to reduced twisted intramolecular charge transfer in the nanoGUMBOS. The electrochemical properties of the PIC-based GUMBOS suggest their potential use in dye-sensitized solar cells.


Assuntos
Ânions/química , Carbocianinas/química , Nanoestruturas/química , Fármacos Fotossensibilizantes/química , Técnicas Eletroquímicas , Polarização de Fluorescência , Teoria Quântica , Energia Solar
6.
Langmuir ; 28(1): 757-65, 2012 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-22112262

RESUMO

Microstructures of sodium deoxycholate hydrogels were altered considerably in the presence of variable tris(hydroxymethyl)aminomethane (TRIS) concentrations. These observations were confirmed by use of X-ray diffraction, polarized optical microscopy, rheology, and differential scanning calorimetry measurements. Our studies reveal enhanced gel crystallinity and rigidity with increasing TRIS concentrations. The tunable hydrogel microstructures obtained under various conditions have been successfully utilized as templates to synthesize cyanine-based fluorescent nanoGUMBOS (nanoparticles from a group of uniform materials based on organic salts). A systematic variation in size (70-200 nm), with relatively low polydispersity and tunable spectral properties of [HMT][AOT] nanoGUMBOS, was achieved by use of these modified hydrogels. The gel microstructures are observed to direct the size as well as molecular self-assembly of the nanomaterials, thereby tuning their spectral properties. These modified hydrogels were also found to possess other interesting properties such as variable morphologies ranging from fibrous to spherulitic, variable degrees of crystallinity, rigidity, optical activity, and release profiles which can be exploited for a multitude of applications. Hence, this study demonstrates a novel method for modification of sodium deoxycholate hydrogels, their applications as templates for nanomaterials synthesis, as well as their potential applications in biotechnology and drug delivery.


Assuntos
Ácido Desoxicólico/química , Hidrogéis , Nanopartículas , Fluorescência , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Difração de Raios X
7.
Percept Mot Skills ; 108(1): 259-70, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19425467

RESUMO

Neuropsychological tests were administered to 62 college students to assess the influence of glyconutrients on perception, cognition and memory in two randomized, double-blind, placebo-controlled, counterbalanced studies. Participants were given both a glyconutritional supplement and a control substance prior to testing. In Exp. 1. a Same-Different visual discrimination task, Raven's Standard Progressive Matrices, and the Stroop test were administered. In Exp. 2, simple and complex working-memory capacity were measured. Participants receiving the supplement performed significantly more accurately on the visual discrimination task and the first session of the simple working-memory test.


Assuntos
Cognição/efeitos dos fármacos , Carboidratos da Dieta/farmacologia , Memória/efeitos dos fármacos , Monossacarídeos/farmacologia , Testes Neuropsicológicos/estatística & dados numéricos , Percepção/efeitos dos fármacos , Adolescente , Adulto , Cognição/fisiologia , Carboidratos da Dieta/administração & dosagem , Suplementos Nutricionais , Discriminação Psicológica , Feminino , Humanos , Masculino , Memória/fisiologia , Memória de Curto Prazo/efeitos dos fármacos , Memória de Curto Prazo/fisiologia , Monossacarídeos/administração & dosagem , Percepção/fisiologia , Percepção Visual/efeitos dos fármacos , Percepção Visual/fisiologia
8.
Apoptosis ; 9(6): 807-14, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15505423

RESUMO

Corpora lutea (CL) were isolated from one rabbit ovary on days 4, 8, 16 (peak luteal function), 28 (functional regression) and 30 of pregnancy and processed for biochemical analysis of DNA integrity. Analysis of DNA integrity revealed the presence of oligonucleosomal fragments in day 28 and day 30 CL but not in day 16 CL. The extent of low molecular weight (<15 kb) DNA labeling was 6.6 +/- 0.84 fold higher in day 30 as compared to day 16 CL (mean +/- SEM; n = 4, P < 0.01). In a second series of experiments, healthy CL collected from day 16 pregnant rabbits were incubated for 2 h in the absence or presence of 250 microg/ml of placental extract (PE) obtained from day 16 and/or day 30 placentas. Analysis of DNA integrity revealed that extensive apoptosis occurred in CL incubated in medium alone and in medium containing day 30 PE. In contrast, day 16 PE significantly suppressed apoptosis vs control (70 +/- 4%). In a third series of experiments, expression of mRNA for bcl-x and bax was measured by Northern analysis of CL treated without and with day 16 PE using cRNA probes for bcl-x and bax developed in our laboratory by RT-PCR. Treatment with PE significantly reduced bax mRNA levels but did not change bcl-x mRNA levels. These studies provide evidence that functional luteolysis in the pregnant rabbit CL is correlated with the occurrence of apoptosis. The data suggest that a factor(s) derived from the placenta may be responsible for the prolongation of CL life span during pregnancy by its ability to alter the bax:bcl -x rheostat and suppress apoptosis.


Assuntos
Apoptose , Corpo Lúteo/fisiologia , Luteólise , Placenta/química , Gravidez/fisiologia , Animais , Sobrevivência Celular , Feminino , Técnicas de Cultura de Órgãos , Progesterona/análise , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Mensageiro/análise , Coelhos , Radioimunoensaio , Fatores de Tempo , Proteína X Associada a bcl-2 , Proteína bcl-X
9.
Reprod Fertil Dev ; 13(5-6): 395-403, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11833936

RESUMO

Apoptosis is a morphologically defined type of cell death initiated by various stimuli that results in the activation of caspases (cysteine-containing aspartate-specific proteases). In the present study, it was determined that caspases are present during, and play a role in, corpus luteum (CL) apoptosis in vitro. Pseudopregnancy was induced in rabbits with 100 IU human chorionic gonadotrophin. On Day 11 of pseudopregnancy, CL were isolated and cultured for 0, 2, 4, 6, and 8 h in the absence of trophic support to induce spontaneous apoptosis. Total RNA was extracted and analysed for caspase-I expression by Northern blot analysis. The results demonstrated caspase-I expression from 4 h. In the second part of the study, CL were incubated without trophic support for 4 h with increasing concentrations of three general caspase inhibitors, sodium aurothiomalate (SAM), iodoacetic acid (IAA) and N-tosyl-L-phenylalanylchloromethylketone (TPCK), and two specific caspase inhibitors, N-acetyl (Ac)-Tyr-Val-Ala-Asp (YVAD)-chloromethylketone (CMK) (Ac-YVAD-CMK) and Ac-Asp-Glu-Val-Asp (DEVD)-aldehyde (CHO) (Ac-DEVD-CHO). At completion, DNA was isolated and integrity assessed. Treatment of CL with SAM, IAA or Ac-DEVD-CHO effectively suppressed apoptotic DNA fragmentation. The final component of the study was to examine caspase-3 protein expression. Western blot analysis revealed a significant increase in caspase-3 expression over the experimental time-course. The results of the present study clearly demonstrate a time-dependent link between the caspases, specifically caspase-3 and spontaneous apoptosis in the rabbit CL.


Assuntos
Apoptose/efeitos dos fármacos , Inibidores de Caspase , Corpo Lúteo/citologia , Inibidores de Cisteína Proteinase/farmacologia , Clorometilcetonas de Aminoácidos/farmacologia , Animais , Western Blotting , Caspase 1/genética , Caspase 3 , Caspases/genética , Gonadotropina Coriônica/farmacologia , Corpo Lúteo/efeitos dos fármacos , Corpo Lúteo/enzimologia , Fragmentação do DNA/efeitos dos fármacos , Feminino , Expressão Gênica , Tiomalato Sódico de Ouro/farmacologia , Humanos , Ácido Iodoacético/farmacologia , Cinética , Oligopeptídeos/farmacologia , Técnicas de Cultura de Órgãos , Fenótipo , Pseudogravidez , RNA Mensageiro/análise , Coelhos , Tosilfenilalanil Clorometil Cetona/farmacologia
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