Displaying publications 1 - 20 of 99 in total

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  1. Sim SM, Hoggard PG, Sales SD, Phiboonbanakit D, Hart CA, Back DJ
    AIDS Res Hum Retroviruses, 1998 Dec 20;14(18):1661-7.
    PMID: 9870320
    Zidovudine (ZDV) is converted to its active triphosphate (ZDVTP) by intracellular kinases. The intermediate ZDV monophosphate (ZDVMP) is believed to play a major role in ZDV toxicity. Manipulation of ZDV phosphorylation is a possible therapeutic strategy for altering the risk-benefit ratio. Here we investigate whether combining RBV with ZDV is able to modulate efficacy and toxicity of ZDV. We have measured the intracellular activation of ZDV (0.3 microM) in the absence and presence of ribavirin (RBV; 2 and 20 microM) in Molt 4 and U937 cells. MTT cytotoxicity of ZDV (10-1000 microM) was also measured with and without RBV (2 microM) in Molt 4 and U937 cells. Measurement of endogenous deoxythymidine triphosphate (dTTP) allowed investigation of the dTTP/ZDVTP ratio. The antiviral efficacy of ZDV in combination with RBV (2 microM) was assessed by HIV p24 antigen measurements. In the presence of RBV (2 and 20 microM) a decrease in total ZDV phosphates was observed, owing mainly to an effect primarily on ZDVMP rather than the active ZDVTP. RBV also increased endogenous dTTP pools in both cell types, resulting in an increase in the dTTP/ZDVTP ratio. ZDV alone significantly reduced p24 antigen production, with an IC50 of 0.34 microM. Addition of RBV increased the IC50 approximately fivefold (1.52 microM). However, at higher concentrations of ZDV (10 and 100 microM) the antagonistic effect of RBV (2 microM) on ZDV was lost. The RBV-mediated decrease in ZDVMP may explain the reduction in ZDV toxicity when combined with RBV (2 microM). Cytotoxicity of ZDV was reduced in the presence of RBV (2 microM) at all concentrations in both cell lines, probably owing to saturation of ZDVTP formation. The interaction of ZDV and RBV is concentration dependent.
    Matched MeSH terms: Anti-HIV Agents/adverse effects; Anti-HIV Agents/pharmacology
  2. Hanna L
    BETA, 1999 Apr;12(2):8-9.
    PMID: 11366704
    Matched MeSH terms: Anti-HIV Agents/therapeutic use*
  3. Xu ZQ, Kern ER, Westbrook L, Allen LB, Buckheit RW, Tseng CK, et al.
    Antivir Chem Chemother, 2000 Jan;11(1):23-9.
    PMID: 10693651
    Plant-derived and semi-synthetic calanolide compounds with anti-human immunodeficiency virus type 1 (HIV-1) activity were tested for anti-human cytomegalovirus (HCMV) activity in both cytopathic effect inhibition and plaque reduction assays. The results indicated that the anti-HCMV activity of calanolide compounds does not correlate with their activity against HIV-1. The semi-synthetic 12-keto derivatives tended to be more active against HCMV than the corresponding 12-OH congeners, which were more active against HIV-1. It appeared that the 7,8-unsaturated double bond in the chromene ring played a certain role in maintaining activities against both HCMV and HIV-1. Saturation of the double bond increased the EC50 values against both viruses, with concomitant increase in toxicity. The calanolide compounds reported here are the first non-nucleoside analogues capable of inhibiting both HIV-1 and HCMV and, therefore, may be useful chemoprophylactic agents for HCMV in HIV-infected people or vice versa.
    Matched MeSH terms: Anti-HIV Agents/chemical synthesis; Anti-HIV Agents/isolation & purification; Anti-HIV Agents/pharmacology*
  4. AIDS Patient Care STDS, 2000 Apr;14(4):225-6.
    PMID: 10806645
    Matched MeSH terms: Anti-HIV Agents/administration & dosage*
  5. Xu ZQ, Norris KJ, Weinberg DS, Kardatzke J, Wertz P, Frank P, et al.
    J Chromatogr B Biomed Sci Appl, 2000 Jun 09;742(2):267-75.
    PMID: 10901131
    A HPLC method was validated for quantification of (+)-calanolide A (1), a novel anti-HIV agent, in rat, dog and human plasma. The synthetic intermediate (+/-)-12-oxocalanolide A (2) was found to be a suitable internal standard. Compounds were extracted from plasma using a solid-phase C(18) cartridge and quantified over the assay range of 12.5 to 800 ng/ml. The method was utilized to determine (+)-calanolide A pharmacokinetics in rats, dogs and humans. This is the first report of a validated HPLC assay for determination of (+)-calanolide A concentrations in rat and dog plasma as well as human plasma obtained from clinical trials. There was no evidence of in vivo epimerization of (+)-calanolide A to its inactive epimer (+)-calanolide B (3).
    Matched MeSH terms: Anti-HIV Agents/administration & dosage; Anti-HIV Agents/blood*; Anti-HIV Agents/pharmacokinetics
  6. De Clercq E
    Med Res Rev, 2000 Sep;20(5):323-49.
    PMID: 10934347
    A large variety of natural products have been described as anti-HIV agents, and for a portion thereof the target of interaction has been identified. Cyanovirin-N, a 11-kDa protein from Cyanobacterium (blue-green alga) irreversibly inactivates HIV and also aborts cell-to-cell fusion and transmission of HIV, due to its high-affinity interaction with gp120. Various sulfated polysaccharides extracted from seaweeds (i.e., Nothogenia fastigiata, Aghardhiella tenera) inhibit the virus adsorption process. Ingenol derivatives may inhibit virus adsorption at least in part through down-regulation of CD4 molecules on the host cells. Inhibition of virus adsorption by flavanoids such as (-)epicatechin and its 3-O-gallate has been attributed to an irreversible interaction with gp120 (although these compounds are also known as reverse transcriptase inhibitors). For the triterpene glycyrrhizin (extracted from the licorice root Glycyrrhiza radix) the mode of anti-HIV action may at least in part be attributed to interference with virus-cell binding. The mannose-specific plant lectins from Galanthus, Hippeastrum, Narcissus, Epipac tis helleborine, and Listera ovata, and the N-acetylgl ucosamine-specific lectin from Urtica dioica would primarily be targeted at the virus-cell fusion process. Various other natural products seem to qualify as HIV-cell fusion inhibitors: the siamycins [siamycin I (BMY-29304), siamycin II (RP 71955, BMY 29303), and NP-06 (FR901724)] which are tricyclic 21-amino-acid peptides isolated from Streptomyces spp that differ from one another only at position 4 or 17 (valine or isoleucine in each case); the betulinic acid derivative RPR 103611, and the peptides tachyplesin and polyphemusin which are highly abundant in hemocyte debris of the horseshoe crabs Tachypleus tridentatus and Limulus polyphemus, i.e., the 18-amino-acid peptide T22 from which T134 has been derived. Both T22 and T134 have been shown to block T-tropic X4 HIV-1 strains through a specific antagonism with the HIV corecept or CXCR4. A number of natural products have been reported to interact with the reverse transcriptase, i.e., baicalin, avarol, avarone, psychotrine, phloroglucinol derivatives, and, in particular, calanolides (from the tropical rainforest tree, Calophyllum lanigerum) and inophyllums (from the Malaysian tree, Calophyllum inophyllum). The natural marine substance illimaquinone would be targeted at the RNase H function of the reverse transcriptase. Curcumin (diferuloylmethane, from turmeric, the roots/rhizomes of Curcuma spp), dicaffeoylquinic and dicaffeoylt artaric acids, L-chicoric acid, and a number of fungal metabolites (equisetin, phomasetin, oteromycin, and integric acid) have all been proposed as HIV-1 integrase inhibitors. Yet, we have recently shown that L-c hicoric acid owes its anti-HIV activity to a specific interaction with the viral envelope gp120 rather than integrase. A number of compounds would be able to inhibit HIV-1 gene expression at the transcription level: the flavonoid chrysin (through inhibition of casein kinase II, the antibacter ial peptides melittin (from bee venom) and cecropin, and EM2487, a novel substance produced by Streptomyces. (ABSTRACT TRUNCATED)
    Matched MeSH terms: Anti-HIV Agents/therapeutic use*; Anti-HIV Agents/chemistry
  7. Balasubramaniam K
    Issues Med Ethics, 2000 Jan-Mar;8(1):26-7.
    PMID: 16323335
    Matched MeSH terms: Anti-HIV Agents/economics*; Anti-HIV Agents/supply & distribution; Anti-HIV Agents/therapeutic use
  8. Foong AL, Ng SF, Lee CK
    J Adv Nurs, 2005 Apr;50(2):134-42.
    PMID: 15788077 DOI: 10.1111/j.1365-2648.2005.03372.x
    AIM: This paper reports a study aimed at identifying the primary health care experiences of people living with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) in Malaysia. The rationale behind the study was to enable informed action for developing more responsive and effective primary care.
    BACKGROUND: Reports such as from the World Health Organisation forecast sharp escalations in the incidence of HIV/AIDS in Malaysia and the Asia-Pacific region within the next few years. With sparse information on the course of infection on the local population and an understanding of health care needs of those afflicted, health services would be ill-prepared for projected increases.
    METHOD: Semi-structured interviews were conducted with a convenience sample of 99 patients attending two major HIV/AIDS clinics in Malaysia.
    FINDINGS: Several gaps in care provision were highlighted, such as with treatment/consultation facilities and availability and accessibility of information. What is also evident is that there are a number of good support services available but not well publicized to those in need of them. That includes health professionals who could be making appropriate referrals. The lack of communications and inter-professional working appears to be part of the problem.
    CONCLUSION: The findings provide baseline data and preliminary insights to government and other service providers towards advancing, optimizing and refining existing policies and infrastructure. Although the availability of a number of primary care facilities have been identified, the study indicates the need for more effective co-ordinated efforts with clear leadership to pull together scarce resources towards the aim of some degree of seamless primary care provision. It is suggested that nurses would be well placed for such a role in view of the nature of their education and training that helps prepare them for the multi-faceted role.

    Study site: One is located
    in the main general hospital in the capital city of Kuala
    Lumpur, and the other in an outpatient clinic on the outskirts
    of the city
    Matched MeSH terms: Anti-HIV Agents/economics
  9. Tee KK, Kamarulzaman A, Ng KP
    AIDS Res Hum Retroviruses, 2006 Feb;22(2):121-4.
    PMID: 16478392
    To assess the prevalence of mutations associated with drug resistance in antiretroviral-naive patients in Kuala Lumpur, Malaysia, genotypic resistance testing was conducted among drug-naive HIV-1 patients attending the University Malaya Medical Center (UMMC) between July 2003 and June 2004. Reverse transcriptase (RT) and protease genes of plasma virions were sequenced from 100 individuals. The majority of the patients were recently diagnosed. Codons 20-255 of the RT and 1-96 of the protease gene were examined for major and minor mutations associated with antiretroviral resistance reported by the International AIDS Society- USA (IAS-USA) Drug Resistance Mutations Group. The prevalence of patients with at least one major mutation conferring drug resistance was 1%, with only one patient having a Y181C amino acid substitution in the RT gene that confers high-level resistance to nevirapine and delavirdine. Minor mutations were detected in high prevalence in the protease gene. Amino acid substitutions I13V, E35D, and M36I were associated with CRF01_AE while L63P, V77I, and I93L were associated with subtype B. Baseline prevalence of major mutations associated with resistance to antiretroviral drugs was low among antiretroviral-naive HIV-1 patients, suggesting that routine drug resistance testing may be unnecessary for all individuals newly diagnosed with HIV or all patients beginning antiretroviral therapy.
    Matched MeSH terms: Anti-HIV Agents/pharmacology*; Anti-HIV Agents/therapeutic use
  10. Tee KK, Kamarulzaman A, Ng KP
    Med Microbiol Immunol, 2006 Jun;195(2):107-12.
    PMID: 16404607
    To assess the prevalence of major drug resistance mutations in antiretroviral (ARV)-treated patients with detectable viral load (VL) in Kuala Lumpur, Malaysia, genotypic resistance testing was performed among treated human immunodeficiency virus type 1 (HIV-1) patients attending the University Malaya Medical Center between July 2003 and November 2004. The reverse transcriptase (RT) and protease genes from 36 plasma samples with detectable VL were examined for major mutations associated with ARV resistance as reported by the International AIDS Society-USA Drug Resistance Mutations Group. The prevalence of patients with at least one major mutation conferring drug resistance to nucleoside RT inhibitors (NRTIs), non-NRTIs (NNRTIs) or protease inhibitors (PIs) was 77.8%. In the RT gene, the frequency of mutations associated with NRTIs and NNRTIs resistance was 52.8 and 63.9%, respectively, with M184V and K103N mutations being selected most frequently by these drugs. A patient with Q151M mutation complex was also detected. Twenty-two percent of the patients had mutations associated with PIs. The following pattern of prevalence of ARV-resistant HIV-1 variants was observed: NNRTI-resistant > NRTI-resistant > PI-resistant. The prevalence of major drug resistance mutations among ARV-treated patients with detectable VL is high in Kuala Lumpur. Genotypic drug resistance testing is therefore important for monitoring patients experiencing ARV regimen failure.
    Matched MeSH terms: Anti-HIV Agents/pharmacology*
  11. Reid G, Kamarulzaman A, Sran SK
    Int J Drug Policy, 2007 Mar;18(2):136-40.
    PMID: 17689356
    In Malaysia the response to illicit drug use has been largely punitive with the current goal of the Malaysian government being to achieve a drug-free society by 2015. This paper outlines the results of a desk-based situation assessment conducted over a 3-week period in 2004. Additional events, examined in 2005, were also included to describe more recent policy developments and examine how these came about. Despite punitive drug policy there has been a substantial rise in the number of drug users in the country. Over two-thirds of HIV/AIDS cases are among injecting drug users (IDUs) and there has been an exponential rise in the number of cases reported. Further, data suggest high risk drug use practices are widespread. Harm reduction initiatives have only recently been introduced in Malaysia. The successful piloting of substitution therapies, in particular methadone and buprenorphine, is cause for genuine hope for the rapid development of such interventions. In 2005 the government announced it will allow methadone maintenance programmes to operate beyond the pilot phase and needle and syringe exchange programmes will be established to serve the needs of IDUs.
    Matched MeSH terms: Anti-HIV Agents/therapeutic use
  12. Lim A, Tan D, Price P, Kamarulzaman A, Tan HY, James I, et al.
    AIDS, 2007 Jul 31;21(12):1525-34.
    PMID: 17630546
    To examine the relationships between blood CD4 natural regulatory T (Treg) cells, plasma HIV RNA level, CD4 T-cell count and immune activation in untreated HIV-infected patients and immunodeficient patients beginning antiretroviral therapy (ART), using a novel phenotype to define Treg cells (CD25CD127CD4). Data were compared with established Treg cell markers (FoxP3, CTLA-4 and GITR).
    Matched MeSH terms: Anti-HIV Agents/therapeutic use*
  13. Razali SM
    Trop Doct, 2008 Apr;38(2):109-10.
    PMID: 18453507 DOI: 10.1258/td.2007.070001
    The prevalence of HIV/AIDS among drug addicts in Malaysia is high, especially among intravenous drug users. The present treatment and rehabilitation of drug addiction is considered as a failure. The government finally decided to start on Drug Substitution Therapy in early 2005 as an effort to prevent the spread of HIV/AIDS in the country.
    Matched MeSH terms: Anti-HIV Agents/administration & dosage; Anti-HIV Agents/therapeutic use
  14. George C, Yesoda A, Jayakumar B, Lal L
    J Clin Pharm Ther, 2009 Feb;34(1):33-40.
    PMID: 19125901 DOI: 10.1111/j.1365-2710.2008.00988.x
    This prospective, observational, study evaluates the clinical outcomes, drug utilization patterns, and adherence to treatment of patients on highly active anti retroviral therapy (HAART) at a government institution in Kerala, India.
    Matched MeSH terms: Anti-HIV Agents/economics*; Anti-HIV Agents/therapeutic use*
  15. Wolfe D, Carrieri MP, Shepard D
    Lancet, 2010 Jul 31;376(9738):355-66.
    PMID: 20650513 DOI: 10.1016/S0140-6736(10)60832-X
    We review evidence for effectiveness, cost-effectiveness, and coverage of antiretroviral therapy (ART) for injecting drug users (IDUs) infected with HIV, with particular attention to low-income and middle-income countries. In these countries, nearly half (47%) of all IDUs infected with HIV are in five nations--China, Vietnam, Russia, Ukraine, and Malaysia. In all five countries, IDU access to ART is disproportionately low, and systemic and structural obstacles restrict treatment access. IDUs are 67% of cumulative HIV cases in these countries, but only 25% of those receiving ART. Integration of ART with opioid substitution and tuberculosis treatment, increased peer engagement in treatment delivery, and reform of harmful policies--including police use of drug-user registries, detention of drug users in centres offering no evidence-based treatment, and imprisonment for possession of drugs for personal use--are needed to improve ART coverage of IDUs.
    Matched MeSH terms: Anti-HIV Agents/economics; Anti-HIV Agents/therapeutic use*
  16. TREAT Asia Pediatric HIV Observational Database (TApHOD), International Epidemiologic Databases to Evaluate AIDS (IeDEA) Southern Africa Paediatric Group
    J Int AIDS Soc, 2011 Feb 09;14:7.
    PMID: 21306608 DOI: 10.1186/1758-2652-14-7
    BACKGROUND: To better understand the need for paediatric second-line antiretroviral therapy (ART), an ART management survey and a cross-sectional analysis of second-line ART use were conducted in the TREAT Asia Paediatric HIV Observational Database and the IeDEA Southern Africa (International Epidemiologic Databases to Evaluate AIDS) regional cohorts.

    METHODS: Surveys were conducted in April 2009. Analysis data from the Asia cohort were collected in March 2009 from 12 centres in Cambodia, India, Indonesia, Malaysia, and Thailand. Data from the IeDEA Southern Africa cohort were finalized in February 2008 from 10 centres in Malawi, Mozambique, South Africa and Zimbabwe.

    RESULTS: Survey responses reflected inter-regional variations in drug access and national guidelines. A total of 1301 children in the TREAT Asia and 4561 children in the IeDEA Southern Africa cohorts met inclusion criteria for the cross-sectional analysis. Ten percent of Asian and 3.3% of African children were on second-line ART at the time of data transfer. Median age (interquartile range) in months at second-line initiation was 120 (78-145) months in the Asian cohort and 66 (29-112) months in the southern African cohort. Regimens varied, and the then current World Health Organization-recommended nucleoside reverse transcriptase combination of abacavir and didanosine was used in less than 5% of children in each region.

    CONCLUSIONS: In order to provide life-long ART for children, better use of current first-line regimens and broader access to heat-stable, paediatric second-line and salvage formulations are needed. There will be limited benefit to earlier diagnosis of treatment failure unless providers and patients have access to appropriate drugs for children to switch to.

    Matched MeSH terms: Anti-HIV Agents/therapeutic use*
  17. Sungkanuparph S, Oyomopito R, Sirivichayakul S, Sirisanthana T, Li PC, Kantipong P, et al.
    Clin Infect Dis, 2011 Apr 15;52(8):1053-7.
    PMID: 21460324 DOI: 10.1093/cid/cir107
    Of 682 antiretroviral-naïve patients initiating antiretroviral therapy in a prospective, multicenter human immunodeficiency virus type 1 (HIV-1) drug resistance monitoring study involving 8 sites in Hong Kong, Malaysia, and Thailand, the prevalence of patients with ≥1 drug resistance mutation was 13.8%. Primary HIV drug resistance is emerging after rapid scaling-up of antiretroviral therapy use in Asia.
    Matched MeSH terms: Anti-HIV Agents/pharmacology*
  18. Sumatoh HR, Oliver BG, Kumar M, Elliott JH, Vonthanak S, Vun MC, et al.
    Biomark Med, 2011 Dec;5(6):847-53.
    PMID: 22103621 DOI: 10.2217/bmm.11.79
    Immune restoration disease (IRD) associated with Mycobacterium tuberculosis parallels the reconstitution of a pathogen-specific Th1 response. However, it is not clear whether humoral responses to M. tuberculosis antigens also rise, or whether antibody levels predict IRD. Here, humoral immunity to M. tuberculosis antigens was investigated in four Asian cohorts.
    Matched MeSH terms: Anti-HIV Agents/therapeutic use
  19. Ali MA, Ismail R, Choon TS, Yoon YK, Wei AC, Pandian S, et al.
    Acta Pol Pharm, 2011 May-Jun;68(3):343-8.
    PMID: 21648188
    A series of novel 3-(substituted phenyl)-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]isoxazole analogues were synthesized by the reaction of 5,6-dimethoxy-2-[(E)-1-phenylmethylidene]-1-indanone with hydroxylamine hydrochloride. The title compounds were tested for their in vitro anti-HIV activity. Among the compounds, (4g) showed a promising anti-HIV activity in the in vitro testing against IIIB and ROD strains. The IC50 of both IIIB and ROD were found to be 9.05 microM and > 125 microM, respectively.
    Matched MeSH terms: Anti-HIV Agents/chemical synthesis*; Anti-HIV Agents/pharmacology*
  20. Chew CS, Cherry CL, Kamarulzaman A, Yien TH, Aghafar Z, Price P
    Dis Markers, 2011;31(5):303-9.
    PMID: 22048272 DOI: 10.3233/DMA-2011-0844
    Chemokines influence the migration of leukocytes to secondary lymphoid tissue and sites of inflammation. In HIV patients, they are implicated in inflammatory complications of antiretroviral therapy (ART), notably Immune Reconstitution Disease (IRD) and Sensory Neuropathy (SN). However most chemokines have not been monitored as patients begin ART or correlated with IRD and SN.
    Matched MeSH terms: Anti-HIV Agents/adverse effects*
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