779 research outputs found

    Neuroprotective role of vitamin D3 in colchicine-induced Alzheimer’s disease in rats

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    Background: Alzheimer’s disease (AD) is a complex neurodegenerative disease characterized by progressive decline in memory, language and other cognitive functions. Recent studies provide convincing evidence on the role of vitamin D3 on the nervous system.Aim: To investigate the effect of the active form of vitamin D3 (1,25-dihydroxycholecalciferol) as a neuroprotective agent in experimentally induced AD in rats.Methods: 40 adult male Wistar (albino) rats weighing 180 to 200 g were included in this study. Rats were divided into four groups (each of 10 rats): Group I: normal healthy rats receiving intracerebroventricular injection (icv) of artificial cerebrospinal fluid (ACSF) and serving as a control group. Group II: rats with induced AD by icv colchicine injection of 15 lg/rat bilaterally and receiving no treatment. Group III: rats pre-treated with active form of vitamin D3 42 IU/kg/day subcutaneously (s.c.) for one week followed by induction of AD then post-treated with vitamin D3 in the same dose for 3 weeks. Group IV: rats with induced AD then post-treated with vitamin D3 for 3 weeks. The following parameters were evaluated in rats of all studied groups1- Behavioral assessment: Morris water maze and open field tasks were performed at days   13, 14 and 21 post-icv injection for assessing cognitive, gross behavioral and motor activities of studied groups.2- Biochemical tests: Hippocampal tissue levels of brain derived neurotrophic factor (BDNF), amyloid beta (Ab) peptide, and antioxidant system; glutathione reductase (GR) and glutathione peroxidase (GPX).Results: The present study revealed a significant increase in time latency of water maze test and hippocampal tissue level of Ab peptide concomitant with significant reduction of hippocampal tissue levels of BDNF, GR and GPX, in untreated AD rats (group II) versus control ACSF-injected rats (group I) and vitamin D3-treated AD rats (groups III and IV). However, group III (AD rats pre- and post-treated with vitamin D3) showed a significant decrease in time latency and Ab peptide, and a significant elevation of BDNF, GR and GPX, versus group IV (AD rats post-treated with vitamin D3).Conclusion: Prophylactic use of active form of vitamin D3 (1,25(OH)2D3) appears to possess a neuroprotective effect in AD involving various mechanisms. Hence, vitamin D3 or its analogues can be considered as promising agents for development of new prophylactic and therapeutic neuroprotectors

    Effect of surfactant and surfactant blends on pseudoternary phase diagram behavior of newly synthesized palm kernel oil esters

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    Background: The purpose of this study was to select appropriate surfactants or blends of surfactants to study the ternary phase diagram behavior of newly introduced palm kernel oil esters. Methods: Nonionic surfactant blends of Tween¼ and Tween¼/Span¼ series were screened based on their solubilization capacity with water for palm kernel oil esters. Tween¼ 80 and five blends of Tween¼ 80/Span¼ 80 and Tween¼ 80/Span¼ 85 in the hydrophilic-lipophilic balance (HLB) value range of 10.7–14.0 were selected to study the phase diagram behavior of palm kernel oil esters using the water titration method at room temperature. Results: High solubilization capacity was obtained by Tween¼ 80 compared with other surfactants of Tween¼ series. High HLB blends of Tween¼ 80/Span¼ 85 and Tween¼ 80/Span¼ 80 at HLB 13.7 and 13.9, respectively, have better solubilization capacity compared with the lower HLB values of Tween¼ 80/Span¼ 80. All the selected blends of surfactants were formed as waterin- oil microemulsions, and other dispersion systems varied in size and geometrical layout in the triangles. The high solubilization capacity and larger areas of the water-in-oil microemulsion systems were due to the structural similarity between the lipophilic tail of Tween¼ 80 and the oleyl group of the palm kernel oil esters. Conclusion: This study suggests that the phase diagram behavior of palm kernel oil esters, water, and nonionic surfactants is not only affected by the HLB value, but also by the structural similarity between palm kernel oil esters and the surfactant used. The information gathered in this study is useful for researchers and manufacturers interested in using palm kernel oil esters in pharmaceutical and cosmetic preparation. The use of palm kernel oil esters can improve drug delivery and reduce the cost of cosmetics

    Effect of surfactant and surfactant blends on pseudoternary phase diagram behavior of newly synthesized palm kernel oil esters

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    Elrashid Saleh Mahdi1, Mohamed HF Sakeena1, Muthanna F Abdulkarim1, Ghassan Z Abdullah1,3, Munavvar Abdul Sattar2, Azmin Mohd Noor11Department of Pharmaceutical Technology, 2Department of Physiology, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, Penang, Malaysia; 3Department of Pharmaceutical Technology, International Medical University, Bukit Jalil, Kuala Lumpur, MalaysiaBackground: The purpose of this study was to select appropriate surfactants or blends of surfactants to study the ternary phase diagram behavior of newly introduced palm kernel oil esters.Methods: Nonionic surfactant blends of Tween® and Tween®/Span® series were screened based on their solubilization capacity with water for palm kernel oil esters. Tween® 80 and five blends of Tween® 80/Span® 80 and Tween® 80/Span® 85 in the hydrophilic-lipophilic balance (HLB) value range of 10.7–14.0 were selected to study the phase diagram behavior of palm kernel oil esters using the water titration method at room temperature.Results: High solubilization capacity was obtained by Tween® 80 compared with other surfactants of Tween® series. High HLB blends of Tween® 80/Span® 85 and Tween® 80/Span® 80 at HLB 13.7 and 13.9, respectively, have better solubilization capacity compared with the lower HLB values of Tween® 80/Span® 80. All the selected blends of surfactants were formed as water-in-oil microemulsions, and other dispersion systems varied in size and geometrical layout in the triangles. The high solubilization capacity and larger areas of the water-in-oil microemulsion systems were due to the structural similarity between the lipophilic tail of Tween® 80 and the oleyl group of the palm kernel oil esters.Conclusion: This study suggests that the phase diagram behavior of palm kernel oil esters, water, and nonionic surfactants is not only affected by the HLB value, but also by the structural similarity between palm kernel oil esters and the surfactant used. The information gathered in this study is useful for researchers and manufacturers interested in using palm kernel oil esters in pharmaceutical and cosmetic preparation. The use of palm kernel oil esters can improve drug delivery and reduce the cost of cosmetics.Keywords: phase diagram, palm kernel oil esters, nonionic surfactants, microemulsion

    The implementation of maintenance system in Malaysia’s public housing at Kota Bharu, Kelantan

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    Establishing an effective maintenance system in public housing buildings is essential in ensuring the building operates optimally and enhances residents' satisfaction. However, the maintenance management in Malaysian public housing is considered low, particularly on leaky roofs, dysfunctional elevators and obstructed pipes. Consequently, the deterioration of facilities and services makes the residents dissatisfied. Consequently, the study aims to determine the current implementation and effectiveness of the maintenance system for public housing by focusing on the residents' satisfaction level and the practice of the maintenance personnel. Surveys were conducted with residents and maintenance personnel from the Projek Perumahan Rakyat Kota Bharu's public housing. A total of 230 questionnaires were considered valid and analyzed to rank the residents' satisfaction level towards public housing maintenance and the practice of the maintenance personnel in public residential buildings. The data was analyzed using the Mean Analysis in the Statistical Package for Social Science (SPSS). The result revealed that the residents are satisfied with the maintenance system's performance, with an electrical system as the most satisfying maintenance performance rated by the residents, compared with other aspects of the maintenance performance factors, with a mean score of 3.94. However, several aspects of the maintenance system, namely cleaning services, security system, and time for repairing the defects, still need improvement to enhance the maintenance quality of public housing in Malaysia

    A Reversible Color Polyphenism in American Peppered Moth (Biston betularia cognataria) Caterpillars

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    Insect body color polyphenisms enhance survival by producing crypsis in diverse backgrounds. While color polyphenisms are often indirectly induced by temperature, rearing density, or diet, insects can benefit from immediate crypsis if they evolve polyphenisms directly induced by exposure to the background color, hence immediately deriving protection from predation. Here, we examine such a directly induced color polyphenism in caterpillars of the geometrid peppered moth (Biston betularia). This larval color polyphenism is unrelated to the genetic polymorphism for melanic phenotypes in adult moths. B. betularia caterpillars are generalist feeders and develop body colors that closely match the brown or green twigs of their host plant. We expand on previous studies examining the proximal cues that stimulate color development. Under controlled rearing conditions, we manipulated diets and background reflectance, using both natural and artificial twigs, and show that visual experience has a much stronger effect than does diet in promoting precise color matching. Their induced body color was not a simple response to reflectance or light intensity but instead specifically matched the wavelength of light to which they were exposed. We also show that the potential to change color is retained until the final (sixth) larval instar. Given their broad host range, this directly induced color polyphenism likely provides the caterpillars with strong protection from bird predation

    Small chromosomes among Danish Candida glabrata isolates originated through different mechanisms

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    We analyzed 192 strains of the pathogenic yeast Candida glabrata from patients, mainly suffering from systemic infection, at Danish hospitals during 1985-1999. Our analysis showed that these strains were closely related but exhibited large karyotype polymorphism. Nine strains contained small chromosomes, which were smaller than 0.5 Mb. Regarding the year, patient and hospital, these C. glabrata strains had independent origin and the analyzed small chromosomes were structurally not related to each other (i.e. they contained different sets of genes). We suggest that at least two mechanisms could participate in their origin: (i) through a segmental duplication which covered the centromeric region, or (ii) by a translocation event moving a larger chromosome arm to another chromosome that leaves the centromere part with the shorter arm. The first type of small chromosomes carrying duplicated genes exhibited mitotic instability, while the second type, which contained the corresponding genes in only one copy in the genome, was mitotically stable. Apparently, in patients C. glabrata chromosomes are frequently reshuffled resulting in new genetic configurations, including appearance of small chromosomes, and some of these resulting "mutant" strains can have increased fitness in a certain patient "environment"

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Contamination of rural surface and ground water by endosulfan in farming areas of the Western Cape, South Africa

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    BACKGROUND: In South Africa there is little data on environmental pollution of rural water sources by agrochemicals. METHODS: This study investigated pesticide contamination of ground and surface water in three intensive agricultural areas in the Western Cape: the Hex River Valley, Grabouw and Piketberg. Monitoring for endosulfan and chlorpyrifos at low levels was conducted as well as screening for other pesticides. RESULTS: The quantification limit for endosulfan was 0.1 Όg/L. Endosulfan was found to be widespread in ground water, surface water and drinking water. The contamination was mostly at low levels, but regularly exceeded the European Drinking Water Standard of 0.1 Όg/L. The two most contaminated sites were a sub-surface drain in the Hex River Valley and a dam in Grabouw, with 0.83 ± 1.0 Όg/L (n = 21) and 3.16 ± 3.5 Όg/L (n = 13) average endosulfan levels respectively. Other pesticides including chlorpyrifos, azinphos-methyl, fenarimol, iprodione, deltamethrin, penconazole and prothiofos were detected. Endosulfan was most frequently detected in Grabouw (69%) followed by Hex River (46%) and Piketberg (39%). Detections were more frequent in surface water (47%) than in groundwater (32%) and coincided with irrigation, and to a lesser extent, to spraying and trigger rains. Total dietary endosulfan intake calculated from levels found in drinking water did not exceed the Joint WHO/FAO Meeting on Pesticide Residues (JMPR) criteria. CONCLUSION: The study has shown the need for monitoring of pesticide contamination in surface and groundwater, and the development of drinking water quality standards for specific pesticides in South Africa

    Successful field trial of attractive toxic sugar bait (ATSB) plant-spraying methods against malaria vectors in the Anopheles gambiae complex in Mali, West Africa

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    <p>Abstract</p> <p>Background</p> <p>Based on highly successful demonstrations in Israel that attractive toxic sugar bait (ATSB) methods can decimate local populations of mosquitoes, this study determined the effectiveness of ATSB methods for malaria vector control in the semi-arid Bandiagara District of Mali, West Africa.</p> <p>Methods</p> <p>Control and treatment sites, selected along a road that connects villages, contained man-made ponds that were the primary larval habitats of <it>Anopheles gambiae </it>and <it>Anopheles arabiensis</it>. Guava and honey melons, two local fruits shown to be attractive to <it>An. gambiae </it>s.l., were used to prepare solutions of Attractive Sugar Bait (ASB) and ATSB that additionally contained boric acid as an oral insecticide. Both included a color dye marker to facilitate determination of mosquitoes feeding on the solutions. The trial was conducted over a 38-day period, using CDC light traps to monitor mosquito populations. On day 8, ASB solution in the control site and ATSB solution in the treatment site were sprayed using a hand-pump on patches of vegetation. Samples of female mosquitoes were age-graded to determine the impact of ATSB treatment on vector longevity.</p> <p>Results</p> <p>Immediately after spraying ATSB in the treatment site, the relative abundance of female and male <it>An. gambiae </it>s.l. declined about 90% from pre-treatment levels and remained low. In the treatment site, most females remaining after ATSB treatment had not completed a single gonotrophic cycle, and only 6% had completed three or more gonotrophic cycles compared with 37% pre-treatment. In the control site sprayed with ASB (without toxin), the proportion of females completing three or more gonotrophic cycles increased from 28.5% pre-treatment to 47.5% post-treatment. In the control site, detection of dye marker in over half of the females and males provided direct evidence that the mosquitoes were feeding on the sprayed solutions.</p> <p>Conclusion</p> <p>This study in Mali shows that even a single application of ATSB can substantially decrease malaria vector population densities and longevity. It is likely that ATSB methods can be used as a new powerful tool for the control of malaria vectors, particularly since this approach is highly effective for mosquito control, technologically simple, inexpensive, and environmentally safe.</p

    Antibacterial Characterization of Novel Synthetic Thiazole Compounds against Methicillin-Resistant Staphylococcus pseudintermedius

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    Staphylococcus pseudintermedius is a commensal organism of companion animals that is a significant source of opportunistic infections in dogs. With the emergence of clinical isolates of S. pseudintermedius (chiefly methicillin-resistant S. pseudintermedius (MRSP)) exhibiting increased resistance to nearly all antibiotic classes, new antimicrobials and therapeutic strategies are urgently needed. Thiazole compounds have been previously shown to possess potent antibacterial activity against multidrug-resistant strains of Staphylococcus aureus of human and animal concern. Given the genetic similarity between S. aureus and S. pseudintermedius, this study explores the potential use of thiazole compounds as novel antibacterial agents against methicillin-sensitive S. pseudintermedius (MSSP) and MRSP. A broth microdilution assay confirmed these compounds exhibit potent bactericidal activity (at sub-microgram/mL concentrations) against both MSSA and MRSP clinical isolates while the MTS assay confirmed three compounds (at 10 ÎŒg/mL) were not toxic to mammalian cells. A time-kill assay revealed two derivatives rapidly kill MRSP within two hours. However, this rapid bactericidal activity was not due to disruption of the bacterial cell membrane indicating an alternative mechanism of action for these compounds against MRSP. A multistep resistance selection analysis revealed compounds 4 and 5 exhibited a modest (twofold) shift in activity over ten passages. Furthermore, all six compounds (at a subinihibitory concentration) demonstrated the ability to re-sensitize MRSP to oxacillin, indicating these compounds have potential use for extending the therapeutic utility of ÎČ-lactam antibiotics against MRSP. Metabolic stability analysis with dog liver microsomes revealed compound 3 exhibited an improved physicochemical profile compared to the lead compound. In addition to this, all six thiazole compounds possessed a long post-antibiotic effect (at least 8 hours) against MRSP. Collectively the present study demonstrates these synthetic thiazole compounds possess potent antibacterial activity against both MSSP and MRSP and warrant further investigation into their use as novel antimicrobial agents
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