Displaying publications 141 - 160 of 203 in total

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  1. Golbabapour S, Gwaram NS, Hassandarvish P, Hajrezaie M, Kamalidehghan B, Abdulla MA, et al.
    PLoS One, 2013;8(9):e75036.
    PMID: 24058648 DOI: 10.1371/journal.pone.0075036
    The study was carried out to assess the gastroprotective effect of the zinc (II) complex against ethanol-induced acute hemorrhagic lesions in rats.
    Matched MeSH terms: Central Nervous System Depressants/adverse effects; Central Nervous System Depressants/pharmacology
  2. Wong KT, Tan CT
    PMID: 22427144 DOI: 10.1007/82_2012_205
    The clinicopathological features of human Nipah virus and Hendra virus infections appear to be similar. The clinical manifestations may be mild, but if severe, includes acute encephalitic and pulmonary syndromes with a high mortality. The pathological features in human acute henipavirus infections comprise vasculopathy (vasculitis, endothelial multinucleated syncytia, thrombosis), microinfarcts and parenchymal cell infection in the central nervous system, lung, kidney and other major organs. Viral inclusions, antigens, nucleocapsids and RNA are readily demonstrated in blood vessel wall and numerous types of parenchymal cells. Relapsing henipavirus encephalitis is a rare complication reported in less than 10% of survivors of the acute infection and appears to be distinct from the acute encephalitic syndrome. Pathological evidence suggests viral recrudescence confined to the central nervous system as the cause.
    Matched MeSH terms: Central Nervous System/pathology*; Central Nervous System/virology
  3. Muthusamy KA, Waran V, Puthucheary SD
    J Clin Neurosci, 2007 Dec;14(12):1213-5.
    PMID: 17964168
    Burkholderia pseudomallei infection of the central nervous system (CNS) is rare with less than 50 cases reported over the last 30 years. The retrospective melioidosis study at University Malaya Medical Centre has documented three cases of CNS melioidosis out of more than 160 cases of melioidosis since 1978. There were two patients with brain abscess and one with spinal epidural abscess. The predisposing factors were: one patient was an aboriginal farmer and the other two were diabetic. Their age ranged from 17 to 45 years. Prominent neurological features were limb weakness, cranial nerve palsy (6th and 7th) and visual disturbance. CT brain scan and MRI spine showed abscess formation, subdural collection, and spinal epidural collection, osteomyelitis of vertebra and occipital bone and also sagital sinus thrombosis. All these patients underwent surgical drainage leading to bacteriological diagnosis as well as appropriate long-term antibiotic therapy. All had good recovery at 6 months after completion of treatment.
    Matched MeSH terms: Central Nervous System Bacterial Infections/microbiology; Central Nervous System Bacterial Infections/pathology*
  4. Mohd Ali N, Mohd Yusof H, Long K, Yeap SK, Ho WY, Beh BK, et al.
    Biomed Res Int, 2013;2013:693613.
    PMID: 23484140 DOI: 10.1155/2013/693613
    Mung bean is a hepatoprotective agent in dietary supplements. Fermentation and germination processes are well recognized to enhance the nutritional values especially the concentration of active compounds such as amino acids and GABA of various foods. In this study, antioxidant and hepatoprotective effects of freeze-dried mung bean and amino-acid- and GABA-enriched germinated and fermented mung bean aqueous extracts were compared. Liver superoxide dismutase (SOD), malondialdehyde (MDA), ferric reducing antioxidant power (FRAP), nitric oxide (NO) levels, and serum biochemical profile such as aspartate transaminase (AST), alanine transaminase (ALT), triglycerides (TG), and cholesterol and histopathological changes were examined for the antioxidant and hepatoprotective effects of these treatments. Germinated and fermented mung bean have recorded an increase of 27.9 and 7.3 times of GABA and 8.7 and 13.2 times of amino acid improvement, respectively, as compared to normal mung bean. Besides, improvement of antioxidant levels, serum markers, and NO level associated with better histopathological evaluation indicated that these extracts could promote effective recovery from hepatocyte damage. These results suggested that freeze-dried, germinated, and fermented mung bean aqueous extracts enriched with amino acids and GABA possessed better hepatoprotective effect as compared to normal mung bean.
    Matched MeSH terms: Central Nervous System Depressants/adverse effects*; Central Nervous System Depressants/pharmacology
  5. Anwar A, Soomaroo A, Anwar A, Siddiqui R, Khan NA
    Exp Parasitol, 2020 Aug;215:107915.
    PMID: 32461112 DOI: 10.1016/j.exppara.2020.107915
    Acanthamoeba castellanii is an opportunistic protozoan responsible for serious human infections including Acanthamoeba keratitis and granulomatous amoebic encephalitis. Despite advances in antimicrobial therapy and supportive care, infections due to Acanthamoeba are a major public concern. Current methods of treatment are not fully effective against both the trophozoite and cyst forms of A. castellanii and are often associated with severe adverse effects, host cell cytotoxicity and recurrence of infection. Therefore, there is an urgent need to develop new therapeutic approaches for the treatment and management of Acanthamoebic infections. Repurposing of clinically approved drugs is a viable avenue for exploration and is particularly useful for neglected and rare diseases where there is limited interest by pharmaceutical companies. Nanotechnology-based drug delivery systems offer promising approaches in the biomedical field, particularly in diagnosis and drug delivery. Herein, we conjugated an antihyperglycemic drug, metformin with silver nanoparticles and assessed its anti-acanthamoebic properties. Characterization by ultraviolet-visible spectrophotometry and atomic force microscopy showed successful formation of metformin-coated silver nanoparticles. Amoebicidal and amoebistatic assays revealed that metformin-coated silver nanoparticles reduced the viability and inhibited the growth of A. castellanii significantly more than metformin and silver nanoparticles alone at both 5 and 10 μM after 24 h incubation. Metformin-coated silver nanoparticles also blocked encystation and inhibited the excystation in Acanthamoeba after 72 h incubation. Overall, the conjugation of metformin with silver nanoparticles was found to enhance its antiamoebic effects against A. castellanii. Furthermore, the pretreatment of A. castellanii with metformin and metformin-coated silver nanoparticles for 2 h also reduced the amoebae-mediated host cell cytotoxicity after 24 h incubation from 73% to 10% at 10 μM, indicating that the drug-conjugated silver nanoparticles confer protection to human cells. These findings suggest that metformin-coated silver nanoparticles hold promise in the improved treatment and management of Acanthamoeba infections.
    Matched MeSH terms: Central Nervous System Protozoal Infections/drug therapy; Central Nervous System Protozoal Infections/parasitology
  6. Gunaseelan S, Ariffin MZ, Khanna S, Ooi MH, Perera D, Chu JJH, et al.
    Nat Commun, 2022 Feb 16;13(1):890.
    PMID: 35173169 DOI: 10.1038/s41467-022-28533-z
    Hand, foot and mouth disease (HFMD) caused by Human Enterovirus A71 (HEVA71) infection is typically a benign infection. However, in minority of cases, children can develop severe neuropathology that culminate in fatality. Approximately 36.9% of HEVA71-related hospitalizations develop neurological complications, of which 10.5% are fatal. Yet, the mechanism by which HEVA71 induces these neurological deficits remain unclear. Here, we show that HEVA71-infected astrocytes release CXCL1 which supports viral replication in neurons by activating the CXCR2 receptor-associated ERK1/2 signaling pathway. Elevated CXCL1 levels correlates with disease severity in a HEVA71-infected mice model. In humans infected with HEVA71, high CXCL1 levels are only present in patients presenting neurological complications. CXCL1 release is specifically triggered by VP4 synthesis in HEVA71-infected astrocytes, which then acts via its receptor CXCR2 to enhance viral replication in neurons. Perturbing CXCL1 signaling or VP4 myristylation strongly attenuates viral replication. Treatment with AZD5069, a CXCL1-specific competitor, improves survival and lessens disease severity in infected animals. Collectively, these results highlight the CXCL1-CXCR2 signaling pathway as a potential target against HFMD neuropathogenesis.
    Matched MeSH terms: Central Nervous System Diseases/pathology; Central Nervous System Diseases/virology*
  7. Lim YC, Quek H, Offenhäuser C, Fazry S, Boyd A, Lavin M, et al.
    J Neurooncol, 2018 Jul;138(3):509-518.
    PMID: 29564746 DOI: 10.1007/s11060-018-2838-0
    Glioblastoma (GBM) is a highly fatal disease with a 5 year survival rate of less than 22%. One of the most effective treatment regimens to date is the use of radiotherapy which induces lethal DNA double-strand breaks to prevent tumour growth. However, recurrence occurs in the majority of patients and is in-part a result of robust radioresistance mechanisms. In this study, we demonstrate that the multifunctional cytokine, interleukin-6 (IL-6), confers a growth advantage in GBM cells but does not have the same effect on normal neural progenitor cells. Further analysis showed IL-6 can promote radioresistance in GBM cells when exposed to ionising radiation. Ablation of the Ataxia-telangiectasia mutated serine/threonine kinase that is recruited and activated by DNA double-strand breaks reverses the effect of radioresistance and re-sensitised GBM to DNA damage thus leading to increase cell death. Our finding suggests targeting the signaling cascade of DNA damage response is a potential therapeutic approach to circumvent IL-6 from promoting radioresistance in GBM.
    Matched MeSH terms: Central Nervous System Neoplasms/metabolism; Central Nervous System Neoplasms/radiotherapy*
  8. Koriem KM, Abdelhamid AZ, Younes HF
    Toxicol. Mech. Methods, 2013 Feb;23(2):134-43.
    PMID: 22992185 DOI: 10.3109/15376516.2012.730561
    Caffeic acid (CA) (3,4-dihydroxycinnamic acid) is among the major hydroxycinnamic acids. Hydroxycinnamic acid is the major subgroup of phenolic compounds. Methamphetamine (METH) is a potent addictive psychostimulant. Chronic use and acute METH intoxication can cause substantial medical consequences, including spleen, kidney, liver and heart. The objective of the present study was to evaluate the antioxidant activity of CA to protect against oxidative stress and DNA damage to various organs in METH toxicity. Thirty-two male Sprague Dawley (SD) rats were divided into four equal groups: group 1 was injected (i.p) with saline (1 mL/kg) while groups 2,3 and 4 were injected (i.p) with METH (10 mg/kg) twice a day over five days period. Where 100 & 200 mg/kg of CA were injected (i.p) into groups 3 and 4, respectively one day before exposure to METH injections. Tissue antioxidants and DNA content were evaluated in different tissues. METH decreased glutathione (GSH) and glutathione peroxidase (GPx) levels while increased malondialdehyde (MDA), catalase (CAT) and protein carbonyl levels in brain (hypothalamus), liver, and kidney tissues of rats. METH increased hyperdiploidy in these tissues and DNA damage results. Prior treatment of CA to animals exposed to METH restores the above parameters to the normal levels and preserves the DNA content of these tissues. These results were supported by histopathological investigations. In conclusion, METH induced oxidative stress and DNA damage and pretreatment of CA before METH injections prevented tissue oxidative stress and DNA damage in METH-treated animals.
    Matched MeSH terms: Central Nervous System Stimulants/toxicity*
  9. Hashim P, Sidek H, Helan MH, Sabery A, Palanisamy UD, Ilham M
    Molecules, 2011;16(2):1310-22.
    PMID: 21278681 DOI: 10.3390/molecules16021310
    Leaves of Centella asiatica (Centella) were analysed for their triterpene composition and bioactivity such as collagen enhancement, antioxidant, anticellulite and UV protection capacity properties. Triterpenes of Centella were measured using HPLC-PAD on an Excil ODS 5 mm (C18) column for the simultaneous determination of asiatic acid, madecassic acid, asiaticoside and madecassoside. Centella was found to contain significant amounts of madecassoside (3.10 ± 4.58 mg/mL) and asiaticoside (1.97 ± 2.65 mg/mL), but was low in asiatic and madecassic acid. The highest collagen synthesis was found at 50 mg/mL of Centella extracts. The antioxidant activity of Centella (84%) was compared to grape seed extract (83%) and Vitamin C (88%). Its lipolytic activity was observed by the release of glycerol (115.9 µmol/L) at 0.02% concentration. Centella extracts exhibited similar UV protection effect to OMC at 10% concentration. In view of these results, the potential application of Centella in food and pharmaceutical industries is now widely open.
    Matched MeSH terms: Central Nervous System Stimulants/pharmacology
  10. Islam MN, Jesmine K, Kong Sn Molh A, Hasnan J
    Leg Med (Tokyo), 2009 Apr;11 Suppl 1:S147-50.
    PMID: 19345131 DOI: 10.1016/j.legalmed.2009.02.035
    A small amount of Methamphetamine (MA) can produce behavioural changes such as euphoria, increased alertness, paranoia, decreased appetite and increased physical activity. In cardiovascular system, it can produce chest pain and hypertension which can result in cardiovascular collapse. In addition, MA causes accelerated heartbeat, elevated blood pressure. It can also cause irreversible damage to blood vessels in the brain. A number of sympathomimetic amines are capable of causing myocardial damage, but the cardio-toxic action of MA has been of particular interest since standardized dosage consistently produces myocardial lesions. As this drug is a choice of many teenagers and young adults, the damage to their health, as well as their future aspects could be greatly affected, therefore more evidence must be sought to convince them the negative root and show them the optimism of recovery and salvation. To clarify the effect of Methamphetamine (MA) on myocardium, 56 male Wister rats aged four weeks were divided equally into MA, Methamphetamine withdrawal (MW), Placebo (P) and Control (C) group were examined following daily intra-peritoneal administration of MA at a dose of 5 mg/kg body weight for 2, 4, 8 and 12 weeks. Normal saline was similarly injected in P group. Light microscopic changes was seen in the myocardium of MA treated group including eosinophilic degeneration, atrophy, hypertrophy, disarray, edema, cellular infiltration, myolysis, granulation tissue, fibrosis and vacuolization. On the other hand, the withdrawal group showed evidence of gradual recovery of those myocardial changes. Optimism is therefore generated about possibility of returning towards normal by withdrawing of this drug by the addicts.
    Matched MeSH terms: Central Nervous System Stimulants/toxicity*
  11. Ponnusamy K, Mohan M, Nagaraja HS
    Med J Malaysia, 2008 Jul;63 Suppl A:102.
    PMID: 19025005
    Lead (Pb) is a neurotoxic heavy metal and children in the developmental stage are particularly susceptible to toxic effects of lead exposure. The brain is the key organ involved in interpreting and responding to potential stressors. Epidemiological investigations have established the relationship between chronic lead exposure and cognitive impairments in young children. Excessive production of radical species plays an important role in neuronal pathology resulting from excitotoxic insults, therefore one plausible neuroprotective mechanism of bioflavonoids is partly relevant to their metal chelating and antioxidant properties. Centella asiatica (CA) is a tropical medicinal plant enriched with bioflavonoids and triterpenes and selenium, reported to rejuvenate the cells and promote physical and mental health. Bioflavonoids are claimed to be exert antimutagenic, neurotrophic and xenobiotics ameliorating and membrane molecular stabilizing effects. The objective of the present work is to study the protective antioxidant effect of pretreatment of CA extract (CAE) on lead acetate induced changes in oxidative biomarkers in the central nervous system (CNS) of mice.
    Matched MeSH terms: Central Nervous System/drug effects
  12. Maneesh M, Dutta S, Chakrabarti A, Vasudevan DM
    Indian J. Physiol. Pharmacol., 2006 Jul-Sep;50(3):291-6.
    PMID: 17193902
    Ethanol is a testicular toxin and it causes fertility abnormalities with low sperm count and impaired sperm motility in men. The present study was designed to investigate plasma testosterone level and hypothalamic pituitary gonadal (HPG) axis function in alcoholic men and also effect of ethanol on systemic oxidative stress. Forty six male alcohol abusers in the age group 20-40 years were selected. Fifty five, males in the same age group served as control. Alcohol abusers had significantly low plasma testosterone with low luteinizing hormone and follicle stimulating hormone. In addition they had significantly high thiobarbituric acid reactive substances (TBARS), superoxide dismutase and glutathione S-transferase, and low glutathione, ascorbic acid, catalase, glutathione reductase and glutathione peroxidase. Moreover, serum testosterone level in alcoholics negatively correlated with duration of alcohol abuse, and TBARS. Duration dependent decreased serum testosterone level in alcohol abusers might be due to 1) increased oxidative stress which can damage Leydig and supporting Sertoli cells and 2) impaired HPG axis.
    Matched MeSH terms: Central Nervous System Depressants/toxicity
  13. Hassan Z, Muzaimi M, Navaratnam V, Yusoff NH, Suhaimi FW, Vadivelu R, et al.
    Neurosci Biobehav Rev, 2013 Feb;37(2):138-51.
    PMID: 23206666 DOI: 10.1016/j.neubiorev.2012.11.012
    Kratom (or Ketum) is a psychoactive plant preparation used in Southeast Asia. It is derived from the plant Mitragyna speciosa Korth. Kratom as well as its main alkaloid, mitragynine, currently spreads around the world. Thus, addiction potential and adverse health consequences are becoming an important issue for health authorities. Here we reviewed the available evidence and identified future research needs. It was found that mitragynine and M. speciosa preparations are systematically consumed with rather well defined instrumentalization goals, e.g. to enhance tolerance for hard work or as a substitute in the self-treatment of opiate addiction. There is also evidence from experimental animal models supporting analgesic, muscle relaxant, anti-inflammatory as well as strong anorectic effects. In humans, regular consumption may escalate, lead to tolerance and may yield aversive withdrawal effects. Mitragynine and its derivatives actions in the central nervous system involve μ-opioid receptors, neuronal Ca²⁺ channels and descending monoaminergic projections. Altogether, available data currently suggest both, a therapeutic as well as an abuse potential.
    Matched MeSH terms: Central Nervous System/drug effects*
  14. Boo NY, Ong LC, Lye MS, Chandran V, Teoh SL, Zamratol S, et al.
    J Paediatr Child Health, 1996 Oct;32(5):439-44.
    PMID: 8933407
    OBJECTIVE: To compare the morbidities in the very low birthweight (VLBW; < 1500 g) and normal birthweight (NBW; > or = 2500 g) Malaysian infants during the first year of life.

    METHODOLOGY: Prospective observational cohort study of consecutive surviving VLBW infants and randomly sampled NBW infants born in the Kuala Lumpur Maternity Hospital between 1 December 1989 and 31 December 1992. Infants were followed up regularly during the first year of life, after correction for prematurity.

    RESULTS: Compared with NBW infants (n = 106), VLBW infants (n = 127) had significantly higher risk of failure to thrive (odds ratio [OR] = 8.0, 95% confidence intervals [CI]: 1.1 to 354.3), wheezing (OR = 3.7, 95% CI: 1.6 to 9.3), rehospitalization (OR = 2.3, 95% CI: 1.1 to 5.0), cerebral palsy (OR = 8.6, 95% CI: 2.0 to 77.6), neurosensory hearing loss (OR = 12.0, 95% CI: 1.7 to 513.6) and visual loss (7.9 vs 0%, P = 0.002). The mean mental developmental index (MDI) and mean psychomotor developmental index (PDI) at 1 year of age were significantly lower among VLBW infants (MDI 99 [SD = 28], PDI 89 [SD = 25]) than NBW infants (MDI 106 [SD = 18], PDI 101 [SD = 18]) (95% CI for difference between means being MDI: -14.1 to -1.7; and PDI: -17.6 to -6.0). Logistic regression analysis showed that among VLBW infants: (i) male sex, Malay ethnicity and bronchopulmonary dysplasia were significant risk factors associated with wheezing; (ii) longer duration of oxygen therapy during the neonatal period, seizures after the post-neonatal period and wheezing were significant risk factors associated with rehospitalization; and (iii) longer duration of oxygen therapy during the neonatal period was a significant risk factor associated with adverse neurodevelopmental outcome during the first year of life.

    CONCLUSIONS: Compared with NBW infants, VLBW Malaysian infants had significantly higher risks of physical and neuro-developmental morbidities.

    Matched MeSH terms: Central Nervous System Diseases/etiology
  15. Tan AK, Azman A, Hoe TS, Rohana T
    Med J Malaysia, 1994 Dec;49(4):409-11.
    PMID: 7674978
    A six-year-old boy, a known case of acute lymphoblastic leukaemia (ALL) on remission since 1991 presented with leukocoria and poor vision of the left eye for two days' duration. Examination revealed endophthalmitis in the left eye with raised intraocular pressure. Anterior chamber paracentesis with vitreous biopsy confirmed a diagnosis of ocular involvement. Further investigation revealed that he also had bone marrow and central nervous system relapse. Clinical manifestation and treatment modalities of ocular involvement in leukaemia are discussed.
    Matched MeSH terms: Central Nervous System/pathology
  16. Low PH, Mangat MS, Liew DNS, Wong ASH
    World Neurosurg, 2020 12;144:e710-e713.
    PMID: 32949798 DOI: 10.1016/j.wneu.2020.09.045
    BACKGROUND: The novel coronavirus disease 2019 (COVID-19) pandemic has set a huge challenge to the delivery of neurosurgical services, including the transfer of patients. We aimed to share our strategy in handling neurosurgical emergencies at a remote center in Borneo island. Our objectives included discussing the logistic and geographic challenges faced during the COVID-19 pandemic.

    METHODS: Miri General Hospital is a remote center in Sarawak, Malaysia, serving a population with difficult access to neurosurgical services. Two neurosurgeons were stationed here on a rotational basis every fortnight during the pandemic to handle neurosurgical cases. Patients were triaged depending on their urgent needs for surgery or transfer to a neurosurgical center and managed accordingly. All patients were screened for potential risk of contracting COVID-19 prior to the surgery. Based on this, the level of personal protective equipment required for the health care workers involved was determined.

    RESULTS: During the initial 6 weeks of the Movement Control Order in Malaysia, there were 50 urgent neurosurgical consultations. Twenty patients (40%) required emergency surgery or intervention. There were 9 vascular (45%), 5 trauma (25%), 4 tumor (20%), and 2 hydrocephalus cases (10%). Eighteen patients were operated at Miri General Hospital, among whom 17 (94.4%) survived. Ninety percent of anticipated transfers were avoided. None of the medical staff acquired COVID-19.

    CONCLUSIONS: This framework allowed timely intervention for neurosurgical emergencies (within a safe limit), minimized transfer, and enabled uninterrupted neurosurgical services at a remote center with difficult access to neurosurgical care during a pandemic.

    Matched MeSH terms: Central Nervous System Vascular Malformations/surgery
  17. Anandakrishnan P, Khoo TB
    BMJ Case Rep, 2018 May 30;2018.
    PMID: 29848532 DOI: 10.1136/bcr-2018-224496
    Cerebral demyelination and optic neuritis are often seen in children with acute disseminated encephalomyelitis following various infections and immunisations. An eight month old girl presented with a left axillary lymph node swelling and an erythematous lace-like rash over her cheeks and trunk. She then developed acute encephalopathy, bilateral nystagmus, right hemiparesis and left facial nerve palsy. Her electroencephalogram showed an encephalopathic process and visual evoked response study were grossly abnormal. Her MRI brain showed hyperintensities in the midbrain, pons and bilateral cerebellar peduncles. She was treated as postinfectious cerebral demyelination with intravenous antibiotics, methylprednisolone and immunoglobulin. Left axillary lymph node excision biopsy and GeneXpert test detected Mycobacterium tuberculosis complex that prompted initiation of antituberculous therapy. Her chest X-ray and cerebrospinal fluid examinations for tuberculosis were normal. She showed significant recovery after 2 weeks. This case illustrates a rare presentation of cerebral demyelination and bilateral optic neuritis following suppurative BCG lymphadenitis.
    Matched MeSH terms: Tuberculosis, Central Nervous System/chemically induced
  18. Chua AS
    World J Gastroenterol, 2006 May 07;12(17):2656-9.
    PMID: 16718748 DOI: 10.3748/wjg.v12.i17.2656
    Dyspepsia itself is not a diagnosis but stands for a constellation of symptoms referable to the upper gastrointestinal tract. It consists of a variable combination of symptoms including abdominal pain or discomfort, postprandial fullness, abdominal bloating, early satiety, nausea, vomiting, heartburn and acid regurgitation. Patients with heartburn and acid regurgitation invariably have gastroesophageal reflux disease and should be distinguished from those with dyspepsia. There is a substantial group of patients who do not have a definite structural or biochemical cause for their symptoms and are considered to be suffering from functional dyspepsia (FD). Gastrointestinal motor abnormalities, altered visceral sensation, dysfunctional central nervous system-enteral nervous system (CNS-ENS) integration and psychosocial factors have all being identified as important pathophysiological correlates. It can be considered as a biopsychosocial disorder with dysregulation of the brain-gut axis being central in origin of disease. FD can be categorized into different subgroups based on the predominant single symptom identified by the patient. This subgroup classification can assist us in deciding the appropriate symptomatic treatment for the patient.
    Matched MeSH terms: Central Nervous System/physiopathology
  19. Harun N, Hassan Z, Navaratnam V, Mansor SM, Shoaib M
    Psychopharmacology (Berl), 2015 Jul;232(13):2227-38.
    PMID: 25616583 DOI: 10.1007/s00213-015-3866-5
    RATIONALE: Mitragynine (MG) is the primary active alkaloid extracted from the leaves of Mitragyna speciosa or kratom and exhibits pharmacological activities mediated by opioid receptors. The plant has been traditionally used for its opium and psychostimulant-like effects to increase work efficiency or as a substitute in the self-treatment of opiate addiction.

    OBJECTIVES: The present study was performed to investigate the discriminative stimulus effects of MG in rats. The pharmacological mechanism of MG action and its derivative, 7-hydroxymitragynine (7-HMG) with a specific focus on opioid receptor involvement was examined in rats trained to discriminate morphine from vehicle. In order to study the dual actions of MG, the effect of cocaine substitution to the MG discriminative stimulus was also performed in MG-trained rats.

    METHODS: Male Sprague Dawley rats were trained to discriminate MG from vehicle in a two-lever drug discrimination procedure under a tandem variable-interval (VI 60') fixed-ratio (FR 10) schedule of food reinforcement.

    RESULTS: Rats acquired the MG discrimination (15.0 mg/kg, i.p.) which was similar to the acquisition of morphine discrimination (5.0 mg/kg, i.p.) in another group of rats. MG substituted fully to the morphine discriminative stimulus in a dose-dependent manner, suggesting pharmacological similarities between the two drugs. The administration of 7-HMG derivative in 3.0 mg/kg (i.p.) dose engendered full generalisation to the morphine discriminative stimulus. In addition, the MG stimulus also partially generalised to cocaine (10.0 mg/kg, i.p.) stimulus.

    CONCLUSION: The present study demonstrates that the discriminative stimulus effect of MG possesses both opioid- and psychostimulant-like subjective effects.

    Matched MeSH terms: Central Nervous System Stimulants/pharmacology
  20. Novick D, Montgomery WS, Aguado J, Peng X, Brugnoli R, Haro JM
    Asia Pac Psychiatry, 2015 Dec;7(4):427-35.
    PMID: 26047023 DOI: 10.1111/appy.12189
    This was an analysis of the impact of somatic symptoms on the severity and course of depression in Chinese patients treated for an acute episode of major depressive disorder (MDD).
    Matched MeSH terms: Central Nervous System Diseases/epidemiology*
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