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1.
Trop Biomed ; 40(2): 152-159, 2023 Jun 01.
Article in English | MEDLINE | ID: mdl-37650400

ABSTRACT

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.


Subject(s)
Anti-Bacterial Agents , Bacteria , Plant Extracts , Humans , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Chloroform/pharmacology , Diospyros/chemistry , Methanol/pharmacology , Plant Extracts/pharmacology , Rutaceae/chemistry , Phyllanthus/chemistry
2.
Tropical Biomedicine ; : 152-159, 2023.
Article in English | WPRIM (Western Pacific) | ID: wpr-1006586

ABSTRACT

@#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.
Article in English | MEDLINE | ID: mdl-30653999

ABSTRACT

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.


Subject(s)
Carrier State/epidemiology , Carrier State/microbiology , Decision Support Techniques , Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae Infections/microbiology , Enterobacteriaceae/enzymology , beta-Lactamases/analysis , Aged , Enterobacteriaceae/isolation & purification , Female , Humans , Male , Middle Aged , Risk Factors
4.
J Gerontol Soc Work ; 59(7-8): 512-536, 2016.
Article in English | MEDLINE | ID: mdl-27824306

ABSTRACT

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.


Subject(s)
Assisted Living Facilities/standards , Personal Satisfaction , Quality of Life/psychology , Aged , Aged, 80 and over , Attitude of Health Personnel , British Columbia , Community Networks , Female , Focus Groups , Humans , Male , Personal Autonomy , Pilot Projects , Safety Management
5.
Nanoscale ; 4(16): 5031-8, 2012 Aug 21.
Article in English | MEDLINE | ID: mdl-22766774

ABSTRACT

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.


Subject(s)
Anions/chemistry , Carbocyanines/chemistry , Nanostructures/chemistry , Photosensitizing Agents/chemistry , Electrochemical Techniques , Fluorescence Polarization , Quantum Theory , Solar Energy
6.
Langmuir ; 28(1): 757-65, 2012 Jan 10.
Article in English | MEDLINE | ID: mdl-22112262

ABSTRACT

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.


Subject(s)
Deoxycholic Acid/chemistry , Hydrogels , Nanoparticles , Fluorescence , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , X-Ray Diffraction
7.
Percept Mot Skills ; 108(1): 259-70, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19425467

ABSTRACT

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.


Subject(s)
Cognition/drug effects , Dietary Carbohydrates/pharmacology , Memory/drug effects , Monosaccharides/pharmacology , Neuropsychological Tests/statistics & numerical data , Perception/drug effects , Adolescent , Adult , Cognition/physiology , Dietary Carbohydrates/administration & dosage , Dietary Supplements , Discrimination, Psychological , Female , Humans , Male , Memory/physiology , Memory, Short-Term/drug effects , Memory, Short-Term/physiology , Monosaccharides/administration & dosage , Perception/physiology , Visual Perception/drug effects , Visual Perception/physiology
8.
Apoptosis ; 9(6): 807-14, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15505423

ABSTRACT

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.


Subject(s)
Apoptosis , Corpus Luteum/physiology , Luteolysis , Placenta/chemistry , Pregnancy/physiology , Animals , Cell Survival , Female , Organ Culture Techniques , Progesterone/analysis , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA, Messenger/analysis , Rabbits , Radioimmunoassay , Time Factors , bcl-2-Associated X Protein , bcl-X Protein
9.
Reprod Fertil Dev ; 13(5-6): 395-403, 2001.
Article in English | MEDLINE | ID: mdl-11833936

ABSTRACT

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.


Subject(s)
Apoptosis/drug effects , Caspase Inhibitors , Corpus Luteum/cytology , Cysteine Proteinase Inhibitors/pharmacology , Amino Acid Chloromethyl Ketones/pharmacology , Animals , Blotting, Western , Caspase 1/genetics , Caspase 3 , Caspases/genetics , Chorionic Gonadotropin/pharmacology , Corpus Luteum/drug effects , Corpus Luteum/enzymology , DNA Fragmentation/drug effects , Female , Gene Expression , Gold Sodium Thiomalate/pharmacology , Humans , Iodoacetic Acid/pharmacology , Kinetics , Oligopeptides/pharmacology , Organ Culture Techniques , Phenotype , Pseudopregnancy , RNA, Messenger/analysis , Rabbits , Tosylphenylalanyl Chloromethyl Ketone/pharmacology
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