Humana leukocytantigen (HLA) är en typ av proteiner som uttrycks på alla cellers yta, de karakteriseras som antigenpresenterande och är en mekanism som ryggradsdjur utvecklat för att lokalisera infekterade eller defekta celler. HLA presenterar peptider från cellens insida för immunförsvaret, vilket i sin tur aktiverar andra delar av immunförsvaret eller inducerar apoptos om främmande peptider presenteras. HIV är ett virus som infekterar celler som uttrycker CD4 på ytan, så som makrofager och T-hjälparceller som ingår i immunförsvaret. Dessa sjunker i antal och immunförsvaret blir försvagat. Obehandlad HIV leder till AIDS, därför är bromsmediciner som Abacavir viktigt. Abacavir har visat goda resultat, dock drabbas 5-8% av hypersensitivitetsreaktioner. Forskare har visat att dessa reaktioner är starkt relaterade till HLA-B*57:01 allelen. Genom screening av denna allel kan behandling med Abacavir undvikas för denna grupp patienter. Syftet med denna studie var att jämföra två olika kit, Olerup SSP® HLA-B*57:01 och Inno-train HLA-READY GENE B57, för typning av HLA-B*57 i 20 olika DNA prover. Dessa jämfördes med den befintliga metoden för HLA-typning som används på klinisk immunologi och transfusionsmedicin, Universitetssjukhuset, Lund. Jämförelsen grundade sig på skillnader mellan kiten, både vad gäller resultat, kostnader och analystider.  Proverna analyserades med PCR innan de separerades på agarosgel med gelelektrofores. Resultaten tolkades enligt tillverkarnas anvisningar. Resultaten visade att båda metoderna kan typa HLA korrekt. Alla resultat med Olerup stämde. Däremot blev 8 av 20 prover fel vid första körningen med Inno-train men resultaten stämde efter omkörning. Avseende kostnader är Inno-train billigare per prov men Olerup skulle bli billigare långsiktigt. För att verkligen fastställa vilket kit som är mest lämpligt behövs fler analyser utföras. / Human leokocyte antigen (HLA), a protein present on the surface of our cells, is characterized as antigen-presenting a mechanism vertebrates have developed to locate infected or defect cells. HLA presents peptides which are brought from the cell's inside to be presented for the immune system. HIV is a virus that infects cells that express CD4 on the surface, such as macrophages and T-helper cells. When these are decreasing, the immune system gets weakened. Untreated HIV leads to AIDS, therefore are inhibiting pharmaceuticals like Abacavir important. Abacavir has shown good results, unfortunately 5-8% gets hypersensitivity-reactions. Scientists have shown that these reactions are strongly related to the HLA-B*57:01 allele. By screening for this allele, treatment with Abacavir could be avoided for this group of patients. The purpose of this study was to compare two different kits, Olerup SSP® HLA-B*57:01 and Inno-train HLA-READY GENE B57, for screening of HLA-B*57 in 20 different DNA samples. These have previously been typed with the established method at the clinical immunology and transfusion medicine, Lund University Hospital. The comparison was based on differences between the kits, both in terms of results, costs and analytical times. PCR was run before the samples were separated on gel with electrophoresis. The results were interpreted in accordance to the manufactures instructions. The results showed that both methods could type HLA correctly. All results from Olerup was correct. However, 8 out of 20 samples showed wrong results at the first run with Inno-train. These were correct after a second run. In terms of costs, Inno-train is cheaper per test, but Olerup would be cheaper in the long term. To really determine which kit is most suitable, more analyzes are required.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19363号 / 医博第4040号 / 新制||医||1011(附属図書館) / 32377 / 新制||医||1011 / 京都大学大学院医学研究科医学専攻 / (主査)教授 小柳 義夫, 教授 河本 宏, 教授 松岡 雅雄 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

L’utilisation d’un traitement antirétroviral, chez la femme enceinte ou chez l’enfant infecté par le VIH, doit être optimale en termes d’efficacité et de tolérance. De nombreuses modifications physiologiques ont lieu tout au long de la grossesse ainsi que pendant les premières années de vie d’un enfant. Ces changements peuvent intervenir à tous les niveaux du devenir du médicament dans l’organisme. Une mauvaise connaissance des variations pharmacocinétiques associées à ces changements physiologiques peut amener à une toxicité ou à une inefficacité de ces traitements. Il est donc primordial de connaître la pharmacocinétique des différentes molécules antirétrovirales recommandées chez la femme enceinte et l’enfant infectés par le VIH. Les pharmacocinétiques de deux inhibiteurs non nucléosidiques de la transcriptase inverse, la zidovudine et l’abacavir et celle d'un inhibiteur de protéase, le lopinavir, ont été étudiées chez la femme enceinte et/ou chez l'enfant par une approche de population. L’évaluation et l’optimisation des recommandations posologiques de ces trois molécules ont été réalisées en tenant compte de relations concentration-effet et/ou concentration-toxicité précédemment établies. L'étude décrivant la pharmacocinétique de l’abacavir a montré qu’une adaptation posologique n’était pas nécessaire pendant la grossesse. En revanche, les études sur la pharmacocinétique de la zidovudine ont montré que les doses recommandées, chez la femme enceinte et chez l’enfant, devraient être diminuées afin de limiter les risques de toxicité. Pour finir, l’étude sur la pharmacocinétique du lopinavir a suggéré qu’il n’était pas nécessaire d’augmenter les posologies pendant la grossesse, contrairement à ce qui est recommandé dans la littérature. / The use of an antiretroviral therapy in pregnant women or in HIV-infected child should be optimal in terms of efficacy and safety. Important physiological changes occur during pregnancy and the first years of life. These changes can affect drug pharmacokinetics. Poor knowledge of pharmacokinetic variations associated with these physiological changes can lead to toxicity or failure of these treatments. Therefore, it is important to know the antiretroviral pharmacokinetics of recommended drugs in pregnant women and in HIV-infected children. The pharmacokinetics of two nucleoside reverse transcriptase inhibitors, zidovudine and abacavir and one protease inhibitor, lopinavir, have been studied in pregnant women and/or in children with a population approach. The evaluation and optimization of dosage recommendations of these three molecules have been achieved using concentration-efficacy and/or concentration-toxicity relationships previously established. The study describing the abacavir pharmacokinetics showed that a dose adjustment was not necessary during pregnancy. However, studies on zidovudine pharmacokinetics presented that the doses recommended in pregnant women and in children should be reduced in order to limit the toxicity risks. Finally, the study on lopinavir pharmacokinetics suggested not to increase the lopinavir dosage during pregnancy contrary to the recommendations of previous studies.

Made available in DSpace on 2015-07-22T20:50:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-11-24. Added 1 bitstream(s) on 2015-08-11T03:25:32Z : No. of bitstreams: 1 Publico-00483a.pdf: 1399809 bytes, checksum: db2c4c756807d9d1d5e11ec653e60536 (MD5). Added 1 bitstream(s) on 2015-08-11T03:25:33Z : No. of bitstreams: 2 Publico-00483a.pdf: 1399809 bytes, checksum: db2c4c756807d9d1d5e11ec653e60536 (MD5) Publico-00483b.pdf: 1297102 bytes, checksum: 7744b75b0f20f0757254b064592deba6 (MD5) / Introdução: Desde a introdução da terapia antirretroviral altamente ativa, infecções como as que ocorrem pelo vírus da Imunodeficiência Humana (HIV) passaram a ser tratadas como uma condição crônica manejável e não mais como uma doença fatal. A suspeita de hipersensibilidade é a principal razão para o início da interrupção do abacavir. O desenvolvimento desta hipersensibilidade por pacientes infectados com o vírus HIV ainda não está completamente esclarecido. Testes genéticos que comprovam a presença do alelo HLA-B*57:01 e permitem a exclusão do uso do abacavir por pacientes portadores deste alelo o que têm demonstrado uma diminuição da incidência de hipersensibilidade entre indivíduos portadores deste vírus. Objetivo: Verificar a prevalência do alelo HLA-B*57 e do alelo específico HLA-B* 57:01 nos pacientes HIV positivos em tratamento com antirretrovirais no Estado de Mato Grosso e estabelecer a eficácia do rastreio prospectivo do alelo específico para impedir a reação de hipersensibilidade ao abacavir. Métodos: As genotipagens para a detecção do alelo HLA-B*5701 foram realizadas por PCR-SSP (Polymerase Chain Reaction - Sequence Specific of Primers) utlilizando um multiplex contendo quatro seqüências dos pares de oligonucleotídios iniciadores. Participaram do estudo 517 pacientes portadores do vírus HIV em tratamento no Centro Estadual de Referência em Média e Alta Complexidade – CERMAC DST/AIDS e/ou encaminhados de outras Unidades de atendimento médico do Estado de Mato Grosso. Resultados: Dos 517 pacientes incluídos no estudo, 385 (74,5%) tiveram resultados de tipagem negativos para o alelo HLA-B*57, 103 (19,9%) foram positivos para este alelo e 29 (5,6%) foram positivos para o alelo específico HLA-B*57:01. Entre os pacientes com resultado negativo para os alelos HLA-B*57 e HLA-B* 57:01, a idade média foi de 40 anos, 205 (53,2%) eram do sexo masculino e 242 (62,9%) eram brancos, já entre os pacientes com resultados positivos para o alelo HLA-B*57, a idade média foi de 38 anos, 47 (45,6%) eram do sexo masculino e 64 (62,1%) eram brancos, enquanto entre os pacientes positivos para o alelo HLA-B*57:01, a idade média foi de 40 anos, 7 (58,6%) eram homens e 15 (57,7%) eram brancos. O medicamento abacavir estava presente no tratamento de 68 pacientes avaliados durante o período do estudo e o alelo HLA-B*57:01 alelo estava presente em 7 (10,3%) destes. Reações de hipersensibilidade foram diagnosticadas em quatro destes pacientes, com uma incidência estatisticamente significativa (p <0,001). Conclusões: O rastreamento do alelo HLA-B*57:01 pode reduzir o risco de hipersensibilidade ao abacavir. Nossos resultados demonstram que testes de biologia molecular podem ser usados para prevenir os efeitos tóxicos de determinadas drogas. / Hypersensitivity reaction to abacavir is strongly associated with the presence of the HLA-B*57:01 allele. This study was designed to establish the prevalence of HLA-B*57:01 among HIV-1 infected individuals in Brazil. A total of 517 consecutive outpatient’s clinics of the State Reference Center in High and Medium Complexity - CERMAC and forwarded to other medical care unit of the Mato Grosso State were followed in this study from february 2008 through july 2010. The presence of HLA-B*57:01 was determined by Nested-PCR with HLA-B*57 and HLA-B*57:01 sequence-specific primers (PCR-SSP). A total of 517 patients were enrolled and randomly assigned to a study group. Of these, 385 (74.5%) were negative for HLA-B*57; 103 (19.9%) were positive for HLA-B*57 and 29 (5.6%) were positive for HLA-B*57:01. Of the HLA-B*57 and HLA-B*57:01 negative patients, the median age was 40 years; 205 (53.2%) were male sex and 242 (62.9%) were Caucasians. Among the patients positive for allele HLA-B*57, the mean age were 38 years; 47 (45.6%) were male sex and 64 (62.1%) were Caucasians. Of the patients positive for allele HLA-B*57:01, the median age was 40 years; 17 (58.6%) were men and 15 (57.7%) were caucasian. An abacavir containing regimen was administerede to 68 patients during the study period, the HLA-B*57:01 alelle was found in 7 (10.3%) of these and the in Hypersensitivity reaction was clinically diagnosed in 4 of these patients, with a statistically significant incidence (p<0.001). / TEDE / BV UNIFESP: Teses e dissertações

The Southern parts of Africa have the highest prevalence of HIV-infected people and South Africa is the country with the highest number of infections in the world. There is still no cure for AIDS, but anti-HIV medicine can prolong and enhance the quality of life of an HIV infected person. Patient adherence with antiretroviral therapy is extremely low due to difficult dosing intervals, problematic dosage forms, instability of the antiretrovirals (ARVs) and the severe side-effects caused by these drugs; this leads to resistance of HIV to these drugs. Pheroid™ technology is a patented delivery system. Pheroid™ vesicles were used during this study. The entrapment of an active within the Pheroid™ would generally provide a safer, more effective formulation than the active alone. This could mean that the amount of drug needed for treatment of HIV can be decreased while producing fewer adverse effects and reducing the price of treatment. The main objectives of this study were to optimise and validate the cell viability and viral replication assays that can be used in an in vitro viral infection model. The MTT assay was used to asses the viability of the cells and to determine the toxicity of the antiretroviral drugs and Pheroid™ on the cells. HIV-1 assays were evaluated and used to determine the viral replication in the cells. Two different continuous cell lines were chosen for this study, an anchorage dependent GHOST cell line and suspended M7-Luc cells. Both these cell lines were best infected with the SWl virus. SWl is a subtype C, CXCR4 utilising virus. Subtype C is responsible for 60 % of the HIV infections worldwide and is the prevalent subtype in SUb-Saharan Africa .. Infection enhancers were not added to the cells to improve viral infection since it was observed that the Pheroid™ in combination with DEAE-dextran or Polybrene caused cytotoxicity probably by disrupting the cell's membrane. Antioxidants were added to the Pheroid ™ formulation since it was observed that the viability of the cells incubated with the Pheroid™ decreased as the Pheroid ™ matured. The added antioxidants had no significant effect on the cells. Abacavir (ABC) was chosen as the test substance for this study since it showed low cytotoxicity in cell cultures and is water soluble and would not present solubility issues in the media. It was entrapped within the Pheroid™ and its in vitro efficacy and toxicity was tested on HIV-infected and uninfected cell cultures. One directlHIV-specific (p24 antigen ELISA assay) and one indirect (Luciferase) assays were used to asses the inhibition of HIV replication caused by ABC. The p24 antigen ELISA (Enzyme-Linked ImmunoSorbent Assay) assay required a lot of washing steps and were rather expensive to use. The Luciferase assay was only used on the M7-Luc cells; this assay was sensitive, inexpensive and easy to use. The MTT (3-(4,5-demethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) viability assay was used to measure the toxicity caused by the Pheroid ™ and/or ABC on the cells. MTT is a widely used quantitative colorimetric assay to measure the viability of cells. The vitamin E and antioxidants contained in the Pheroid ™ reduced the MTT and produced results that were misinterpreted as enhanced viability when the Pheroid™ was present during MTT analysis. To prevent this problem an additional washing step should be introduced prior to analysis to reduce the interference of the Pheroid ™ with analytical methods. In conclusion, the efficacy of ABC entrapped within the Pheroid™ is still inconclusive and further studies will have to be done. MTT should be used with care for viability analysis of cells incubated in the presence of Pheroid TM. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2009.

The Southern parts of Africa have the highest prevalence of HIV-infected people and South Africa is the country with the highest number of infections in the world. There is still no cure for AIDS, but anti-HIV medicine can prolong and enhance the quality of life of an HIV infected person. Patient adherence with antiretroviral therapy is extremely low due to difficult dosing intervals, problematic dosage forms, instability of the antiretrovirals (ARVs) and the severe side-effects caused by these drugs; this leads to resistance of HIV to these drugs. Pheroid™ technology is a patented delivery system. Pheroid™ vesicles were used during this study. The entrapment of an active within the Pheroid™ would generally provide a safer, more effective formulation than the active alone. This could mean that the amount of drug needed for treatment of HIV can be decreased while producing fewer adverse effects and reducing the price of treatment. The main objectives of this study were to optimise and validate the cell viability and viral replication assays that can be used in an in vitro viral infection model. The MTT assay was used to asses the viability of the cells and to determine the toxicity of the antiretroviral drugs and Pheroid™ on the cells. HIV-1 assays were evaluated and used to determine the viral replication in the cells. Two different continuous cell lines were chosen for this study, an anchorage dependent GHOST cell line and suspended M7-Luc cells. Both these cell lines were best infected with the SWl virus. SWl is a subtype C, CXCR4 utilising virus. Subtype C is responsible for 60 % of the HIV infections worldwide and is the prevalent subtype in SUb-Saharan Africa .. Infection enhancers were not added to the cells to improve viral infection since it was observed that the Pheroid™ in combination with DEAE-dextran or Polybrene caused cytotoxicity probably by disrupting the cell's membrane. Antioxidants were added to the Pheroid ™ formulation since it was observed that the viability of the cells incubated with the Pheroid™ decreased as the Pheroid ™ matured. The added antioxidants had no significant effect on the cells. Abacavir (ABC) was chosen as the test substance for this study since it showed low cytotoxicity in cell cultures and is water soluble and would not present solubility issues in the media. It was entrapped within the Pheroid™ and its in vitro efficacy and toxicity was tested on HIV-infected and uninfected cell cultures. One directlHIV-specific (p24 antigen ELISA assay) and one indirect (Luciferase) assays were used to asses the inhibition of HIV replication caused by ABC. The p24 antigen ELISA (Enzyme-Linked ImmunoSorbent Assay) assay required a lot of washing steps and were rather expensive to use. The Luciferase assay was only used on the M7-Luc cells; this assay was sensitive, inexpensive and easy to use. The MTT (3-(4,5-demethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) viability assay was used to measure the toxicity caused by the Pheroid ™ and/or ABC on the cells. MTT is a widely used quantitative colorimetric assay to measure the viability of cells. The vitamin E and antioxidants contained in the Pheroid ™ reduced the MTT and produced results that were misinterpreted as enhanced viability when the Pheroid™ was present during MTT analysis. To prevent this problem an additional washing step should be introduced prior to analysis to reduce the interference of the Pheroid ™ with analytical methods. In conclusion, the efficacy of ABC entrapped within the Pheroid™ is still inconclusive and further studies will have to be done. MTT should be used with care for viability analysis of cells incubated in the presence of Pheroid TM. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2009.

The aim of this study is forced oxidative degradation of active pharmaceutical ingredient abacavir, used to treat HIV-infected patients. A fast and sensitive method for the determination of abacavir and its degradation products by ultra-high performance liquid chromatography has been developed and validated, that made it possible to evaluate the oxidation stability of abacavir and Ziagen tablets. Suitable chromatographic separation was achieved using a Kinetex C18 column and gradient elution with a mobile phase consisting of acetonitrile and ammonium acetate (c = 20 mmol dm−3 , pH = 7.0). The total run time was 11 minutes. The determination of abacavir and its degradation products was performed by a photodiode array detector at λ = 254 nm. The optimized method for the determination of abacavir and its degradation products was applied to study the oxidation of abacavir by both traditional and electrochemical approaches. The forced degradation study in solution revealed abacavir instability in the presence of 3% hydrogen peroxide and during electrochemical oxidation. The study found that excipients in the tablet suppress the degradation of abacavir by approximately 10 %. Abacavir is oxidized by 15 % by hydrogen peroxide after 24 hours at 25 řC, after 1.5 hours at 50 řC and after 5 minutes at...

A crucial step in the drug discovery and development process is the assessment of membrane permeability properties of new chemical entities and researchers are constantly searching for cost-effective, high through-put models with as high as possible predictive value. In addition, a thorough understanding of the membrane permeability pathways and metabolism mechanisms are required when evaluating drug disposition and pharmacokinetics. Various in vitro methods/techniques are available to measure the rate of permeation of compounds across epithelial cell membranes to estimate oral drug absorption in humans. The aim of this study is to compare three in vitro models (i.e. excised rat intestinal tissue, excised pig intestinal tissue and Caco-2 human cell cultures) in terms of drug permeability characteristics by means of different techniques including the Ussing type Sweetana-Grass diffusion chamber apparatus, everted sac glass apparatus and the Transwell® plate apparatus. The transport of abacavir sulphate was determined in two directions (i.e. apical-to-basolateral or AP - BL and basolateral-to-apical or BL - AP) across excised rat intestinal tissue, excised pig intestinal tissue and Caco-2 cell monolayers. The test solution was applied to the donor side and samples (200 μl) were drawn from the acceptor side at 20 min intervals for a period of 2 h. The concentration of abacavir in the samples was then measured by means of a validated high performance liquid chromatography (HPLC) method. The transepithelial electrical resistance (TEER) was measured before and after each transport experiment to give an indication of the integrity of the cell membranes. The apparent permeability coefficient (Papp) and efflux ratio (ER) values were calculated and used to compare the different methods and techniques in terms of drug permeation characteristics. All three of the in vitro methods, in all of the techniques employed, showed higher transport of abacavir in the BL - AP direction than in the AP - BL direction. This indicates that all three in vitro methods had intact active efflux transporters over the entire study period. The excised rat intestinal method showed similar drug permeability characteristics in both techniques compared to that of the Caco-2 cell monolayers. In contrast, the excised pig intestinal method only showed similar drug permeability characteristics in the Sweetana-Grass diffusion apparatus when compared to the Caco-2 cell monolayers. This phenomenon can possibly be explained by the relatively large surface area of the pig tissue used in the everted sac technique where the role of physiological and other factors take effect. These factors may include the thickness of the membrane and mucus layer as well as variables such as diet, age, gender and size of the pigs obtained from the abattoir that cannot be controlled. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2015

A crucial step in the drug discovery and development process is the assessment of membrane permeability properties of new chemical entities and researchers are constantly searching for cost-effective, high through-put models with as high as possible predictive value. In addition, a thorough understanding of the membrane permeability pathways and metabolism mechanisms are required when evaluating drug disposition and pharmacokinetics. Various in vitro methods/techniques are available to measure the rate of permeation of compounds across epithelial cell membranes to estimate oral drug absorption in humans. The aim of this study is to compare three in vitro models (i.e. excised rat intestinal tissue, excised pig intestinal tissue and Caco-2 human cell cultures) in terms of drug permeability characteristics by means of different techniques including the Ussing type Sweetana-Grass diffusion chamber apparatus, everted sac glass apparatus and the Transwell® plate apparatus. The transport of abacavir sulphate was determined in two directions (i.e. apical-to-basolateral or AP - BL and basolateral-to-apical or BL - AP) across excised rat intestinal tissue, excised pig intestinal tissue and Caco-2 cell monolayers. The test solution was applied to the donor side and samples (200 μl) were drawn from the acceptor side at 20 min intervals for a period of 2 h. The concentration of abacavir in the samples was then measured by means of a validated high performance liquid chromatography (HPLC) method. The transepithelial electrical resistance (TEER) was measured before and after each transport experiment to give an indication of the integrity of the cell membranes. The apparent permeability coefficient (Papp) and efflux ratio (ER) values were calculated and used to compare the different methods and techniques in terms of drug permeation characteristics. All three of the in vitro methods, in all of the techniques employed, showed higher transport of abacavir in the BL - AP direction than in the AP - BL direction. This indicates that all three in vitro methods had intact active efflux transporters over the entire study period. The excised rat intestinal method showed similar drug permeability characteristics in both techniques compared to that of the Caco-2 cell monolayers. In contrast, the excised pig intestinal method only showed similar drug permeability characteristics in the Sweetana-Grass diffusion apparatus when compared to the Caco-2 cell monolayers. This phenomenon can possibly be explained by the relatively large surface area of the pig tissue used in the everted sac technique where the role of physiological and other factors take effect. These factors may include the thickness of the membrane and mucus layer as well as variables such as diet, age, gender and size of the pigs obtained from the abattoir that cannot be controlled. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2015