MyMedR

Displaying publications 41 - 60 of 813 in total

Abstract:

Sort:

Sodium carboxymethylcellulose scaffolds and their physicochemical effects on partial thickness wound healing

Ramli NA, Wong TW

Int J Pharm, 2011 Jan 17;403(1-2):73-82.
PMID: 20974238 DOI: 10.1016/j.ijpharm.2010.10.023

This study investigated critical physicochemical attributes of low (LV), medium (MV) and high molecular weight (HV) sodium carboxymethylcellulose (SCMC) scaffolds in partial thickness wound healing. SCMC scaffolds were prepared by solvent-evaporation technique. Their in vitro erosion, moisture affinity, morphology, tensile strength, polymer molecular weight and carboxymethyl substitution, and in vivo wound healing profiles were determined. Inferring from rat wound size, re-epithelialization and histological profiles, wound healing progressed with HV scaffold>LV-MV scaffold>control with no scaffold. The transepidermal water loss (TEWL) from wound of rats treated by control>HV scaffold>LV-MV scaffold. HV scaffold had the highest tensile strength of all matrices and was resistant to erosion in simulated wound fluid. In spite of constituting small nanopores, it afforded a substantial TEWL than MV and LV scaffolds from wound across an intact matrix through its low moisture affinity characteristics. The HV scaffold can protect moisture loss without its excessive accumulation at wound bed which hindered re-epithelialization process. Regulation of transepidermal water movement and wound healing by scaffolds was governed by SCMC molecular weight instead of its carboxymethyl substitution degree or matrix pore size distribution, with large molecular weight HV preferred over lower molecular weight samples.

Matched MeSH terms: Disease Models, Animal
Fulltext Formaldehyde-inactivated whole-virus vaccine protects a murine model of enterovirus 71 encephalomyelitis against disease

Ong KC, Devi S, Cardosa MJ, Wong KT

J Virol, 2010 Jan;84(1):661-5.
PMID: 19864378 DOI: 10.1128/JVI.00999-09

Enterovirus 71 (EV71) causes childhood hand, foot, and mouth disease and neurological complications, and no vaccines or therapeutic drugs are currently available. Formaldehyde-inactivated whole-virus vaccines derived from EV71 clinical isolates and a mouse-adapted virus (MAV) were tested in a mouse model of EV71 encephalomyelitis. After only two immunizations, given to mice at 1 and 7 days of age, the MAV vaccine protected mice at 14 days of age from disease. Tissues from immunized mice were negative for virus by viral culture, reverse transcriptase PCR, immunohistochemistry analysis, and in situ hybridization. Cross-neutralizing EV71 antibodies to strains with genotypes B3, B4, and C1 to C5 generated in immunized adult mice were able to passively protect 14-day-old mice from disease.

Matched MeSH terms: Disease Models, Animal
Fulltext Pathologic characterization of a murine model of human enterovirus 71 encephalomyelitis

Ong KC, Badmanathan M, Devi S, Leong KL, Cardosa MJ, Wong KT

J. Neuropathol. Exp. Neurol., 2008 Jun;67(6):532-42.
PMID: 18520772 DOI: 10.1097/NEN.0b013e31817713e7

We describe a model of Enterovirus 71 encephalomyelitis in 2-week-old mice that shares many features with the human central nervous system (CNS) disease. Mice were infected via oral and parenteral routes with a murine-adapted virus strain originally from a fatal human case. The mice succumbed to infection after 2 to 5 days. Vacuolated and normal-appearing CNS neurons showed viral RNA and antigens and virions by in situ hybridization, immunohistochemistry, and electron microscopy; inflammation was minimal. The most numerous infected neurons were in anterior horns, motor trigeminal nuclei, and brainstem reticular formation; fewer neurons in the red nucleus, lateral cerebellar nucleus, other cranial nerve nuclei, motor cortex, hypothalamus, and thalamus were infected. Other CNS regions, dorsal root, and autonomic ganglia were spared. Intramuscular-inoculated mice killed 24 to 36 hours postinfection had viral RNA and antigens in ipsilateral lumbar anterior horn cells and adjacent axons. Upper cord motor neurons, brainstem, and contralateral motor cortex neurons were infected from 48-72 hours. Viral RNA and antigens were abundant in skeletal muscle and adjacent tissues but not in other organs. The distinct, stereotypic viral distribution in this model suggests that the virus enters the CNS via peripheral motor nerves after skeletal muscle infection, and spread within the CNS involves motor and other neural pathways. This model may be useful for further studies on pathogenesis and for testing therapies.

Matched MeSH terms: Disease Models, Animal*
A monoclonal antibody to ameliorate central nervous system infection and improve survival in a murine model of human Enterovirus-A71 encephalomyelitis

Tan SH, Ong KC, Perera D, Wong KT

Antiviral Res, 2016 Aug;132:196-203.
PMID: 27340013 DOI: 10.1016/j.antiviral.2016.04.015

BACKGROUND: Enterovirus A71 (EV-A71) encephalomyelitis is an often fatal disease for which there is no specific treatment available. Passive immunization with a specific monoclonal antibody to EV-A71 was used on a murine model of EV-A71 encephalomyelitis to evaluate its therapeutic effectiveness before and after established central nervous system (CNS) infection.
METHODS: Mice were intraperitoneally-infected with a mouse-adapted EV-A71 strain and treated with a dose of monoclonal antibody (MAb) daily for 3 days on day 1, 2 and 3 post-infection or for 3 days on 3, 4 and 5 post-infection. Treatment effectiveness was evaluated by signs of infection and survival rate. Histopathology and qPCR analyses were performed on mice sacrificed a day after completing treatment.
RESULTS: In mock-treated mice, CNS infection was established from day 3 post-infection. All mice treated before established CNS infection, survived and recovered completely without CNS infection. All mice treated after established CNS infection survived with mild paralysis, and viral load and antigens/RNA at day 6 post-infection were significantly reduced.
CONCLUSIONS: Passive immunization with our MAb could prevent CNS infection in mice if given early before the establishment of CNS infection. It could also ameliorate established CNS infection if optimal and repeated doses were given.

Matched MeSH terms: Disease Models, Animal
Fulltext A Consistent Orally-Infected Hamster Model for Enterovirus A71 Encephalomyelitis Demonstrates Squamous Lesions in the Paws, Skin and Oral Cavity Reminiscent of Hand-Foot-and-Mouth Disease

Phyu WK, Ong KC, Wong KT

PLoS One, 2016;11(1):e0147463.
PMID: 26815859 DOI: 10.1371/journal.pone.0147463

Enterovirus A71 (EV-A71) causes self-limiting, hand-foot-and-mouth disease (HFMD) that may rarely be complicated by encephalomyelitis. Person-to-person transmission is usually by fecal-oral or oral-oral routes. To study viral replication sites in the oral cavity and other tissues, and to gain further insights into virus shedding and neuropathogenesis, we developed a consistent, orally-infected, 2-week-old hamster model of HFMD and EV-A71 encephalomyelitis. Tissues from orally-infected, 2-week-old hamsters were studied by light microscopy, immunohistochemistry and in situ hybridization to detect viral antigens and RNA, respectively, and by virus titration. Hamsters developed the disease and died after 4-8 days post infection; LD50 was 25 CCID50. Macroscopic cutaneous lesions around the oral cavity and paws were observed. Squamous epithelium in the lip, oral cavity, paw, skin, and esophagus, showed multiple small inflammatory foci around squamous cells that demonstrated viral antigens/RNA. Neurons (brainstem, spinal cord, sensory ganglia), acinar cells (salivary gland, lacrimal gland), lymphoid cells (lymph node, spleen), and muscle fibres (skeletal, cardiac and smooth muscles), liver and gastric epithelium also showed varying amounts of viral antigens/RNA. Intestinal epithelium, Peyer's patches, thymus, pancreas, lung and kidney were negative. Virus was isolated from oral washes, feces, brain, spinal cord, skeletal muscle, serum, and other tissues. Our animal model should be useful to study squamous epitheliotropism, neuropathogenesis, oral/fecal shedding in EV-A71 infection, person-to-person transmission, and to test anti-viral drugs and vaccines.

Matched MeSH terms: Disease Models, Animal
Coxsackievirus A16 in a 1-Day-Old Mouse Model of Central Nervous System Infection Shows Lower Neurovirulence than Enterovirus A71

Hooi YT, Ong KC, Tan SH, Perera D, Wong KT

J Comp Pathol, 2020 Apr;176:19-32.
PMID: 32359633 DOI: 10.1016/j.jcpa.2020.02.001

Coxsackievirus A16 (CV-A16) and enterovirus A71 (EV-A71) are the major causes of hand, foot and mouth disease in young children. Although less so with CV-A16, both viruses are associated with serious neurological syndromes, but the differences between their central nervous system infections remain unclear. We conducted a comparative infection study using clinically-isolated CV-A16 and EV-A71 strains in a 1-day-old mouse model to better understand the neuropathology and neurovirulence of the viruses. New serotype-specific probes for in situ hybridization were developed and validated to detect CV-A16 and EV-A71 RNA in infected tissues. Demonstration of CV-A16 virus antigens/RNA, mainly in the brainstem and spinal cord neurons, confirmed neurovirulence, but showed lower densities than in EV-A71 infected animals. A higher lethal dose50 for CV-A16 suggested that CV-A16 is less neurovirulent. Focal virus antigens/RNA in the anterior horn white matter and adjacent efferent motor nerves suggested that neuroinvasion is possibly via retrograde axonal transport in peripheral motor nerves.

Matched MeSH terms: Disease Models, Animal
Fulltext Modelling person-to-person transmission in an Enterovirus A71 orally infected hamster model of hand-foot-and-mouth disease and encephalomyelitis

Phyu WK, Ong KC, Wong KT

Emerg Microbes Infect, 2017 Jul 12;6(7):e62.
PMID: 28698666 DOI: 10.1038/emi.2017.49

Enterovirus A71 (EV-A71) causes hand-foot-and-mouth disease (HFMD), which may be complicated by fatal encephalomyelitis. Although fecal-oral or oral-oral routes are important in person-to-person transmission, how viral shedding and exposure may predispose individuals to infection remains unknown. We investigated person-to-person transmission by using a model of HFMD and encephalomyelitis based on EV-A71 oral infection of 2-week-old hamsters. Animals (index animals) infected with 104 50% cell culture infective doses of virus uniformly developed severe disease four days post-infection (dpi), whereas littermate contacts developed severe disease after six to seven days of exposure to index animals. Virus was detected in oral washes and feces at 3-4 dpi in index animals and at three to eight days after exposure to index animals in littermate contact animals. In a second experiment, non-littermate contact animals exposed for 8 or 12 h to index animals developed the disease six and four days post-exposure, respectively. Tissues from killed index and contact animals, studied by light microscopy, immunohistochemistry and in situ hybridization, exhibited mild inflammatory lesions and/or viral antigens/RNA in the squamous epithelia of the oral cavity, tongue, paws, skin, esophagus, gastric epithelium, salivary glands, lacrimal glands, central nervous system neurons, muscles (skeletal, cardiac and smooth muscles) and liver. Orally shed viruses were probably derived from infected oral mucosa and salivary glands, whereas fecal viruses may have derived from these sites as well as from esophageal and gastric epithelia. Asymptomatic seroconversion in exposed mother hamsters was demonstrated. Our hamster model should be useful in studying person-to-person EV-A71 transmission and how drugs and vaccines may interrupt transmission.

Matched MeSH terms: Disease Models, Animal*
Japanese Encephalitis Virus Infects the Thalamus Early Followed by Sensory-Associated Cortex and Other Parts of the Central and Peripheral Nervous Systems

Fu TL, Ong KC, Tan SH, Wong KT

J. Neuropathol. Exp. Neurol., 2019 12 01;78(12):1160-1170.
PMID: 31675093 DOI: 10.1093/jnen/nlz103

Japanese encephalitis (JE) is a known CNS viral infection that often involves the thalamus early. To investigate the possible role of sensory peripheral nervous system (PNS) in early neuroinvasion, we developed a left hindlimb footpad-inoculation mouse model to recapitulate human infection by a mosquito bite. A 1-5 days postinfection (dpi) study, demonstrated focal viral antigens/RNA in contralateral thalamic neurons at 3 dpi in 50% of the animals. From 4 to 5 dpi, gradual increase in viral antigens/RNA was observed in bilateral thalami, somatosensory, and piriform cortices, and then the entire CNS. Infection of neuronal bodies and adjacent nerves in dorsal root ganglia (DRGs), trigeminal ganglia, and autonomic ganglia (intestine, etc.) was also observed from 5 dpi. Infection of explant organotypic whole brain slice cultures demonstrated no viral predilection for the thalamus, while DRG and intestinal ganglia organotypic cultures confirmed sensory and autonomic ganglia susceptibility to infection, respectively. Early thalamus and sensory-associated cortex involvement suggest an important role for sensory pathways in neuroinvasion. Our results suggest that JE virus neuronotropism is much more extensive than previously known, and that the sensory PNS and autonomic system are susceptible to infection.

Matched MeSH terms: Disease Models, Animal
A novel orally infected hamster model for Coxsackievirus A16 hand-foot-and-mouth disease and encephalomyelitis

Hooi YT, Ong KC, Tan SH, Perera D, Wong KT

Lab Invest, 2020 Sep;100(9):1262-1275.
PMID: 32601355 DOI: 10.1038/s41374-020-0456-x

Coxsackievirus A16 (CV-A16) is one of the major causes of mild and self-limiting hand-foot-and-mouth disease (HFMD) in young children, which may occasionally leads to serious neurological complications. In this study, we had developed a novel, consistent, orally infected CV-A16 HFMD hamster model with encephalomyelitis. Four groups of 7-day-old hamsters in a kinetic study were orally infected with mouse-adapted CV-A16 strains and sacrificed at 1-4 days post infection (dpi), respectively. Tissues were studied by light microscopy, immunohistochemistry to detect viral antigens, in situ hybridization to detect viral RNA, and by viral titration. In a separate transmission experiment, orally infected index hamsters were housed together with contact hamsters to investigate oral and fecal viral shedding by virus culture and reverse transcription polymerase chain reaction (RT-PCR). At severe infection/death endpoints, index and contact hamster infection were also histopathologically analyzed. In the kinetic study, infected hamsters developed signs of infection at 4 dpi. Viral antigens/RNA were localized to brainstem (medulla/pons; reticular formation and motor trigeminal nucleus) and spinal cord anterior horn neurons, oral squamous epithelia and epidermis from 3 to 4 dpi. Salivary and lacrimal glands, myocardium, brown adipose tissue, intestinal smooth muscle, and skeletal muscle infection was also demonstrated. Viremia at 1 dpi and increasing viral titers in various tissues were observed from 2 dpi. In the transmission study, all contact hamsters developed disease 3-5 days later than index hamsters, but demonstrated similar histopathological findings at endpoint. Viral culture and RT-PCR positive oral washes and feces confirmed viral shedding. Our hamster model, orally infected by the natural route for human infection, confirmed CV-A16 neurotropism and demonstrated squamous epitheliotropism reminiscent of HFMD, attributes not found in other animal models. It should be useful to investigate neuropathogenesis, model person-to-person transmission, and for testing antiviral drugs and vaccines.

Matched MeSH terms: Disease Models, Animal*
Tioman virus infection in experimentally infected mouse brain and its association with apoptosis

Yaiw KC, Ong KC, Chua KB, Bingham J, Wang L, Shamala D, et al.

J Virol Methods, 2007 Aug;143(2):140-6.
PMID: 17442409

Tioman virus is a newly described bat-urine derived paramyxovirus isolated in Tioman Island, Malaysia in 2001. Hitherto, neither human nor animal infection by this virus has been reported. Nonetheless, its close relationship to another paramyxovirus, the Menangle virus which had caused diseases in humans and pigs [Philbey, A.W., Kirkland, P.D., Ross, A.D., Davis, R.J., Gleeson, A.B., Love, R.J., Daniels, P.W., Gould, A.R., Hyatt, A.D., 1998. An apparently new virus (family Paramyxoviridae) infectious for pigs, humans, and fruit bats. Emerg. Infect. Dis. 4, 269-271], raises the possibility that it may be potentially pathogenic. In this study, mice were experimentally infected with Tioman virus by intraperitoneal and intracerebral routes, and the cellular targets and topographical distribution of viral genome and antigens were examined using in situ hybridization and immunohistochemistry, respectively. The possible association between viral infection and apoptosis was also investigated using the TUNEL assay and immunohistochemistry to FasL, Caspase-3, Caspase-8, Caspase-9 and bcl-2. The results showed that Tioman virus inoculated intracerebrally was neurotropic causing plaque-like necrotic areas, and appeared to preferentially replicate in the neocortex and limbic system. Viral infection of inflammatory cells was also demonstrated. TUNEL and Caspase-3 positivity was found in inflammatory cells but not in neurons, while FasL, Caspase-8 and Caspase-9 were consistently negative. This suggests that neuronal infection was associated with necrosis rather than apoptosis. Moreover, the data suggest that there may be an association between viral infection and apoptosis in inflammatory cells, and that it could, at least in part, involve Caspase-independent pathways. Bcl-2 was expressed in some neurons and inflammatory cells indicating its possible role in anti-apoptosis. There was no evidence of central nervous system infection via the intraperitoneal route.

Matched MeSH terms: Disease Models, Animal
Fulltext The Monkey Head Mushroom and Memory Enhancement in Alzheimer's Disease

Yanshree, Yu WS, Fung ML, Lee CW, Lim LW, Wong KH

Cells, 2022 Jul 24;11(15).
PMID: 35892581 DOI: 10.3390/cells11152284

Alzheimer's disease (AD) is a neurodegenerative disorder, and no effective treatments are available to treat this disorder. Therefore, researchers have been investigating Hericium erinaceus, or the monkey head mushroom, an edible medicinal mushroom, as a possible treatment for AD. In this narrative review, we evaluated six preclinical and three clinical studies of the therapeutic effects of Hericium erinaceus on AD. Preclinical trials have successfully demonstrated that extracts and bioactive compounds of Hericium erinaceus have potential beneficial effects in ameliorating cognitive functioning and behavioral deficits in animal models of AD. A limited number of clinical studies have been conducted and several clinical trials are ongoing, which have thus far shown analogous outcomes to the preclinical studies. Nonetheless, future research on Hericium erinaceus needs to focus on elucidating the specific neuroprotective mechanisms and the target sites in AD. Additionally, standardized treatment parameters and universal regulatory systems need to be established to further ensure treatment safety and efficacy. In conclusion, Hericium erinaceus has therapeutic potential and may facilitate memory enhancement in patients with AD.

Matched MeSH terms: Disease Models, Animal
Fulltext In vitro and ex-vivo cellular antioxidant protection and cognitive enhancing effects of an extract of Polygonum minus Huds (Lineminus™) demonstrated in a Barnes Maze animal model for memory and learning

George A, Ng CP, O'Callaghan M, Jensen GS, Wong HJ

BMC Complement Altern Med, 2014;14:161.
PMID: 24886679 DOI: 10.1186/1472-6882-14-161

Polygonum minus Huds.is a culinary flavouring that is common in South East Asian cuisine and as a remedy for diverse maladies ranging from indigestion to poor eyesight. The leaves of this herb have been reported to be high in antioxidants. Flavonoids which have been associated with memory, cognition and protection against neurodegeneration were found in P. minus.

Matched MeSH terms: Disease Models, Animal
An overview of Acinetobacter baumannii pathogenesis: Motility, adherence and biofilm formation

Mea HJ, Yong PVC, Wong EH

Microbiol Res, 2021 Jun;247:126722.
PMID: 33618061 DOI: 10.1016/j.micres.2021.126722

The Gram-negative opportunistic pathogen Acinetobacter baumannii has gain notoriety in recent decades, primarily due to its propensity to cause nosocomial infections in critically ill patients. Its global spread, multi-drug resistance features and plethora of virulence factors make it a serious threat to public health worldwide. Though much effort has been expended in uncovering its successes, it continues to confound researchers due to its highly adaptive nature, mutating to meet the needs of a given environment. Its persistence in the clinical setting allows it to be in close proximity to a potential host, where contact can be made facilitating infection and colonization. In this article, we aim to provide a current overview of the bacterial virulence factors, specifically focusing on factors involved in the initial stages of infection, highlighting the role of adaptation facilitated by two-component systems and biofilm formation. Finally, the study of host-pathogen interactions using available animal models, their suitability, notable findings and some perspectives moving forward are also discussed.

Matched MeSH terms: Disease Models, Animal
Study on the use of toltrazuril to eliminate Neospora caninum in congenitally infected lambs born from experimentally infected ewes

Syed-Hussain SS, Howe L, Pomroy WE, West DM, Hardcastle M, Williamson NB

Vet Parasitol, 2015 Jun 15;210(3-4):141-4.
PMID: 25935293 DOI: 10.1016/j.vetpar.2015.03.019

To determine if toltrazuril was effective in eliminating Neospora caninum infection from congenitally infected lambs. Twenty-eight ewes were allocated to 3 groups where animals in Groups A and B were inoculated with 1 × 10(7)N. caninum tachyzoites on Day 120 of gestation and Group C was maintained as a negative control group. Lambs born from ewes in Group A were treated with toltrazuril (20mg/kg) on Days 0, 7, 14 and 21 after birth. Lambs in Groups B and C were untreated. All lambs in Groups A and B were seropositive at 12 weeks of age. At 12 weeks of age, no differences between lambs in Group A and Group B were observed in serological results (ELISA and western blot), presence of N. caninum-related brain histopathological lesions or the number of organisms detected by qPCR. Group C remained negative for serology, detection of N. caninum DNA as well as histopathology throughout the study. Results indicate that N. caninum congenitally-infected lambs had a continuing infection with N. caninum despite being treated with toltrazuril.

Matched MeSH terms: Disease Models, Animal
Fulltext Effect of Polymethylmethacrylate-Hydroxyapatite Composites on Callus Formation and Compressive Strength in Goat Vertebral Body

Komang-Agung IS, Hydravianto L, Sindrawati O, William PS

Malays Orthop J, 2018 Nov;12(3):6-13.
PMID: 30555640 DOI: 10.5704/MOJ.1811.002

Introduction: Percutaneous vertebroplasty (PV) is one of the available treatments for vertebral compression fracture (VCF). Polymethylmethacrylate (PMMA) is the most common bone substitute used in the procedure, but it has several disadvantages. Bioceramic material, such as hydroxyapatite (HA), has better biological activity compared to PMMA. The aim of this study was to find an optimal biomaterial compound which offers the best mechanical and biological properties to be used in PV. Materials and Methods: This was an experimental study with goat (Capra aegagrus hircus) as an animal model. The animals' vertebral columns were injected with PMMA-HA compound. Animal samples were divided into four groups, and each group received a different proportion of PMMA:HA compound. The mechanical and biological effects of the compound on the bone were then analysed. The mechanical effect was assessed by measuring the vertebral body's compressive strength. Meanwhile, the biological effect was assessed by analysing the callus formation in the vertebral body. Results: The optimal callus formation and compressive strength was observed in the group receiving PMMA:HA with a 1:2 ratio. Conclusion: A mixture of PMMA and HA increases the quality of callus formation and the material's compressive strength. The optimum ratio of PMMA:HA in the compound is 1:2.

Matched MeSH terms: Disease Models, Animal
Fulltext Mangosteen xanthone γ-mangostin exerts lowering blood glucose effect with potentiating insulin sensitivity through the mediation of AMPK/PPARγ

Chen SP, Lin SR, Chen TH, Ng HS, Yim HS, Leong MK, et al.

Biomed Pharmacother, 2021 Dec;144:112333.
PMID: 34678724 DOI: 10.1016/j.biopha.2021.112333

Diabetes mellitus (DM) is concomitant with significant morbidity and mortality and its prevalence is accumulative in worldwide. The conventional antidiabetic agents are known to mitigate the symptoms of diabetes; however, they may also cause side and adverse effects. There is an imperative necessity to conduct preclinical and clinical trials for the discovery of alternative therapeutic agents that can overcome the drawbacks of current synthetic antidiabetic drugs. This study aimed to investigate the efficacy of lowering blood glucose and underlined mechanism of γ-mangostin, mangosteen (Garcinia mangostana) xanthones. The results showed γ-Mangostin had a antihyperglycemic ability in short (2 h)- and long-term (28 days) administrations to diet-induced diabetic mice. The long-term administration of γ-mangostin attenuated fasting blood glucose of diabetic mice and exhibited no hepatotoxicity and nephrotoxicity. Moreover, AMPK, PPARγ, α-amylase, and α-glucosidase were found to be the potential targets for simulating binds with γ-mangostin after molecular docking. To validate the docking results, the inhibitory potency of γ-mangostin againstα-amylase/α-glucosidase was higher than Acarbose via enzymatic assay. Interestingly, an allosteric relationship between γ-mangostin and insulin was also found in the glucose uptake of VSMC, FL83B, C2C12, and 3T3-L1 cells. Taken together, the results showed that γ-mangostin exerts anti-hyperglycemic activity through promoting glucose uptake and reducing saccharide digestion by inhibition of α-amylase/α-glucosidase with insulin sensitization, suggesting that γ-mangostin could be a new clue for drug discovery and development to treat diabetes.

Matched MeSH terms: Disease Models, Animal
Pharmacological Activity of Pyrazole Derivatives as an Anticonvulsant for Benefit against Epilepsy

Gao M, Qu K, Zhang W, Wang X

Neuroimmunomodulation, 2021;28(2):90-98.
PMID: 33774633 DOI: 10.1159/000513297

INTRODUCTION: Pediatric patients with epilepsy are prone to cognitive impairments during growth and long-term use of most antiepileptic drugs (AED). The affected children do not respond to conventional AED and may require novel drugs to manage the disease. Valproic acid, a first-line drug to treat epilepsy, is associated with serious side effects, which precludes its wider use. Thus, in the present study, we intended to develop novel substituted pyrazoles.
METHODS: The molecules were tested for anticonvulsive activity in Swiss albino mice via maximal electroshock seizure and subcutaneous pentylenetetrazole assays. The most potent molecule among the class was further assayed for its effect on behavioral and CNS depressant activity. The effect of the most potent compounds was also analyzed on various indices of oxidative stress and inflammation in mice.
RESULTS: The designed compounds showed significant anticonvulsive activity in mice revealing 7h as the most potent anticonvulsive agent. The most potent anticonvulsant molecule 7h further showed no behavioral alteration and considerable CNS depressant activity. It also reduces the level of oxidative stress and inflammation in the mice.
CONCLUSION: Our study demonstrated utility of pyrazole derivatives as anticonvulsants against epilepsy.

Matched MeSH terms: Disease Models, Animal
Novel metabolites from Trichoderma atroviride against human prostate cancer cells and their inhibitory effect on Helicobacter pylori and Shigella toxin producing Escherichia coli

Saravanakumar K, Mandava S, Chellia R, Jeevithan E, Babu Yelamanchi RS, Mandava D, et al.

Microb Pathog, 2018 Oct 10;126:19-26.
PMID: 30316006 DOI: 10.1016/j.micpath.2018.10.011

The present study aimed to purify and identify the metabolites from T. atroviride using high-performance liquid chromatography (HPLC) and 1H and 13C nuclear magnetic resonance spectrometer (NMR) followed by analyzing their toxicological, antibacterial and anticancer properties. This work identified two metabolites - TM1 and TM2. TM1 was in two forms: (i) 1, 3-dione-5, 5-dimethylcyclohexane; and, (ii) 2-enone-3hydroxy -5,5-dimethylcylohex, while TM2 was 4H-1,3-dioxin-4-one-2,3,6-trimethyl. These metabolites did not exhibit any irritant or allergic reaction as revealed by HET- CAM test. TM2 significantly inhibited the growth of H. pylori and Shigella toxin producing Escherichia coli (STEC) as evident by in vitro and microscopic observations of bacterial cell death. TM2 also induced the cell death and cytotoxicity, as revealed by cell viability test and western blot analysis. According to microscopic, flow cytometer and western blot analysis, TM2 treated cells displayed higher ROS, cell death, and apoptosis-related protein expression than TM1 and control. This study concluded that TM2 derived from T. atroviride was a potential therapeutic agent for anti-prostate cancer and antibiotic agent against MDR- H. pylori and STEC and it is also recommended to carry out further in vivo animal model experiments with improved stability of the metabolites for future pharmaceutical trails.

Matched MeSH terms: Models, Animal
Fulltext Subclinical infection without encephalitis in mice following intranasal exposure to Nipah virus-Malaysia and Nipah virus-Bangladesh

Dups J, Middleton D, Long F, Arkinstall R, Marsh GA, Wang LF

Virol J, 2014;11:102.
PMID: 24890603 DOI: 10.1186/1743-422X-11-102

Nipah virus and Hendra virus are closely related and following natural or experimental exposure induce similar clinical disease. In humans, encephalitis is the most serious outcome of infection and, hitherto, research into the pathogenesis of henipavirus encephalitis has been limited by the lack of a suitable model. Recently we reported a wild-type mouse model of Hendra virus (HeV) encephalitis that should facilitate detailed investigations of its neuropathogenesis, including mechanisms of disease recrudescence. In this study we investigated the possibility of developing a similar model of Nipah virus encephalitis.

Matched MeSH terms: Disease Models, Animal*
Hendra and Nipah viruses: pathogenesis and therapeutics

Eaton BT, Broder CC, Wang LF

Curr Mol Med, 2005 Dec;5(8):805-16.
PMID: 16375714

Within the past decade a number of new zoonotic paramyxoviruses emerged from flying foxes to cause serious disease outbreaks in man and livestock. Hendra virus was the cause of fatal infections of horses and man in Australia in 1994, 1999 and 2004. Nipah virus caused encephalitis in humans both in Malaysia in 1998/99, following silent spread of the virus in the pig population, and in Bangladesh from 2001 to 2004 probably as a result of direct bat to human transmission and spread within the human population. Hendra and Nipah viruses are highly pathogenic in humans with case fatality rates of 40% to 70%. Their genetic constitution, virulence and wide host range make them unique paramyxoviruses and they have been given Biosecurity Level 4 status in a new genus Henipavirus within the family Paramyxoviridae. Recent studies on the virulence, host range and cell tropisms of henipaviruses provide insights into the unique biological properties of these emerging human pathogens and suggest approaches for vaccine development and therapeutic countermeasures.

Matched MeSH terms: Disease Models, Animal

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links