Objetivos: Avaliar fatores de risco e diferentes métodos diagnósticos para retinopatia nos usuários crônicos do difosfato de cloroquina, portadores de lúpus eritematoso sistêmico. Métodos: Foram avaliados 72 olhos de 36 pacientes consecutivos, seguidos no Serviço de Reumatologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, entre julho de 2007 e abril de 2008. Dados demográficos e clínicos foram pesquisados para estudar os fatores de alto risco (dose diária acima de 3,0 mg/Kg, dose cumulativa, alterações renais, alterações hepáticas, idade acima de 60 anos) e compará-los com os seguintes métodos diagnósticos: acuidade visual, testes de Amsler com grade branca e vermelha, biomicroscopia da córnea, biomicroscopia do fundo, retinografia, angiofluoresceinografia da retina, campo visual dos 10 graus centrais com mira branca, testes de visão de cores, Panel D15 e HRR. Resultados: Dos 36 pacientes, 34 (94,4 %) eram mulheres. A média de idade foi 39,9±9,8 anos, com tempo de doença igual a 13,9±6,6 anos e tempo de uso da cloroquina igual a 11,9±5,1 anos. Além do uso crônico, os pacientes apresentaram altas doses diárias (4,4±0,4 mg, segundo peso ideal e 5,4±0,6 mg, segundo peso magro) e cumulativas (1092,2±476,6 g). Não foi observada relação entre os fatores de alto risco estudados e maior prevalência de retinopatia. A prevalência de retinopatia, confirmada por alterações bilaterais, centrais ou paracentrais e reprodutíveis nos exames de campo visual, foi de 38.9 %. Outros exames indicados para seguimento, como acuidade visual, biomicroscopia da córnea, biomicroscopia do fundo, teste de Amsler, Panel D15 e angiofluoresceinografia do fundo, não foram capazes de diagnosticar a maioria das alterações confirmadas pelo campo visual. O teste de visão de cores HRR apresentou alta sensibilidade e boa especificidade. A intensidade dos achados no HRR mostrou relação com a intensidade dos achados no campo visual. Conclusão: Foi observada alta prevalência de retinopatia por cloroquina entre os pacientes usuários crônicos da cloroquina. A avaliação desses pacientes deve considerar a realização do exame de campo visual e testes de visão de cores mais específicos para as maculopatias adquiridas, mesmo quando não há suspeita clínica. / Purpose: To evaluate risk factors and screnning methods for retinopathy in systemic lupus erythematosus patients after chronic use of chloroquine. Methods: Seventy-two eyes of 36 consecutive patients, followed in the Division of Rheumatology of Hospital das Clínicas, School of Medicine, São Paulo University, were analised from July 2007 to April 2008. Demographic and clinical data were evaluated in order to study risk factors and compare different ophthalmological methods as following: visual acuity, Amsler grid, corneal biomicroscopy, fundus examination, retinography, fluorescein retinography, visual field, color vision tests. Results: From 36 patients, 34 (94,4 %) were female. The mean age was 39,9± 9,8 years and disease duration was 13,9±6,6 years. Besides chronic use of chloroquine, patients also showed high daily (4,4±0,4 mg) and cumulative (1092,2 ±476,6 g) doses. These high risk factors were not related to higher prevalence of retinopathy. Visual field showed 38.9 % retinopathy prevalence. Other ophthalmological methods failed in detecting most cases. Color vision test HRR was highly sensitive but not so specific in detecting retinopathy. The intensity of alterations in HRR were related to the intensity of visual field alterations. Conclusion: High prevalence of retinopathy in chronic users of chloroquine patients was detected by visual field test, but other screening methods failed in detecting alterations. Ophthalmological assessment of these patients should include visual field and color vision tests specific for acquired maculopathies, even in the absence of clinical alterations.

Thesis (PH.D. (Medical Sciences)) --University of Limpopo, 2010 / Refere to document

[Truncated abstract] Iron is essential to most biological systems. Under pathological conditions affecting the iron metabolic pathway, iron can be deposited in the tissue in various forms. The work presented in this thesis has exploited the relationship between the magnetic and the chemical properties of tissue iron deposits to further understanding of two major pathologies, the haemoglobinopathies termed thalassaemias and the malaria parasite Plasmodium falciparum, both amongst the most common health concerns in tropical countries. The iron-specific magnetic susceptibilities ¿Fe for spleen tissue samples from 7 transfusion dependent ß-thalassaemia (ß-thal) patients and 11 non-transfusion dependent ß-thalassaemia/Haemoglobin E (ß/E) patients were measured at 37°C. Both groups of patients were iron loaded with no significant difference in the distribution of spleen iron concentrations between the two groups. There was a significant difference between the mean ¿Fe of the spleen tissue from each group. The ß/E patients had a higher mean (± standard deviation) spleen ¿Fe (1.55 ± 0.23 × 10-6 m3.kgFe -1) than the ß-thal patients (1.16 ± 0.25 × 10-6 m3.kgFe -1). Correlations were observed between ¿Fe of the spleen tissue and the fraction of magnetic hyperfine split sextet in the 57Fe Mössbauer spectra of the tissues at 78 K (Spearman rank order correlation ¿ = -0.54, p = 0.03) and between ¿Fe of the spleen tissue and the fraction of doublet in the spectra at 5 K (¿ = 0.58, p = 0.02) indicating that ¿Fe of the spleen tissue is related to the chemical speciation of the iron 2 deposits in the tissue. The biological variability of the iron-specific magnetic susceptibility of the tissue iron examined would contribute a random uncertainty of 19% to magnetic susceptibility based non-invasive measurements of tissue iron concentration. ... Magnetic susceptibility measurements were also performed on malaria parasitised red blood cells. In vitro cultures of P. falciparum were magnetically enriched up to 61-fold using high field gradient magnetic separation columns, and the magnetic susceptibility of cell contents was directly measured. Forms of haem iron were quantified spectroscopically. Further fractionations were performed such that, by controlling the fluid velocity through the column, cells with more than a critical amount of paramagnetic 3 iron were preferentially extracted. A chloroquine-sensitive (CQS) laboratory strain of parasites converted approximately 60% of host cell haem iron to haemozoin and this product was the primary source of the increase in cell magnetic susceptibility. The volumetric magnetic susceptibility of the magnetically enriched cells was found to be 0.15 ± 0.03 × 10-7 relative to the suspension medium, accounting for the enrichment of mature parasites. Comparisons of fractionation samples of two pairs of CQS and chloroquine resistant (CQR) strains showed enrichment of mature parasites was significantly greater in the CQS than the CQR strains. The results suggest the possibility of using magnetic separation columns in identifying CQR strains of P. falciparum, potentially in a diagnostic or research setting. The study also underlines the need to identify and quantify the forms of iron in CQR and CQS parasite strains as the fate of haem iron will have implications in understanding the mechanisms of chloroquine resistance.

<p>Malaria is the most common parasitic disease of humans worldwide. A factor that aggravates the many attempts to control the epidemiologic malaria situation is the spreading of resistance against anti-malarial drugs. In this project the point mutation at position 86 of the <em>Plasmodium. </em><em>falciparum</em><em> </em>multidrug resistance gene (<em>pfmdr1</em>), which is thought to contribute to Chloroquine resistance, was analysed in 188 samples from a low transmission area in eastern Sudan, where malaria endemicity is seasonal. The patient group studied had asymptomatic and sub patent parasitemia that persisted during the transmission-free dry season, after being treated with Chloroquine. To differentiate between wild type and mutant genotypes, nested PCR and restriction fragment length polymorphism with the enzyme Apo1 was used. Out of 188 samples 79 (42%) were successfully analysed. Of those, 72% had parasites with mutant genotypes or where mixed infection. No conclusions on the relevance of the <em>pfmd</em><em>r</em><em>1</em> gene in the studied samples are made due to the many remaining gaps. However, eventual sources of error and previous findings in the study area are discussed.</p>

Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2009.

Endocrine resistance is a significant clinical problem in the treatment of estrogen (E2) receptor positive breast cancers. There are two ER subtypes, ERα and ERβ, which promote and inhibit breast cancer cell proliferation respectively. While ER positive breast cancers typically express a high ratio of ERα to ERβ, the acquisition of antiestrogen resistance in vitro and in vivo is associated with increased relative expression of the ERβ. On some gene enhancers ERβ has been shown to function in opposition to the ERα in the presence of E2. Here we demonstrate that exposure to two different ERβ agonists results in decreased cell viability, and produced a marked reduction in G2/M phase in antiestrogen resistant breast cancer cell line in conjunction with altered cyclin D1, and cyclin E expression relative to E2. ERβ agonists also strongly downregulated Bcl-2 expression and recruited both ERs to the Bcl-2 and pS2 E2-response elements resulting in a reduction in mRNA transcripts from both of these genes. Bcl-2 reduction correlated with increased lipidation of LC3-I to LC3-II, indicative of increased autophagic flux. Although ERβ agonist treatment alone did not induce apoptosis, remarkably, the coaddition of ERβ agonist and the autophagy inhibitor, chloroquine, resulted in robust cell death. Lastly, in vivo studies demonstrate that preferential-ERβ agonists are not estrogenic in the uterus or mammary gland. Together, these observations suggest that combined therapies including an ERβ agonist and an autophagy inhibitor may provide the basis for a safe, novel approach to the treatment of antiestrogen-resistant breast cancers.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2009. / Härtill 6 uppsatser.

The emergence of multidrug resistant tumours during the course of chemotherapeutic treatment of cancer patients is a major obstacle in cancer chemotherapy. Although several mechanisms may contribute to the appearance of multidrug resistance phenotype (MDR) in tumour cells, reduced drug accumulation and the ability of cells to undergo apoptosis are thought to be very important in expression of MDR. The work in this thesis focuses on the mechanism responsible for the reduced drug accumulation in tumour cells, mainly the multidrug resistance protein (MRP1). / The molecular mechanism underlying the binding and efflux of drugs by the MRP1 is currently not well understood. Several studies have now demonstrated that the cysteinyl leukotriene C$ sb4$ (LTC$ sb4$) and other glutathione (GSH) S-conjugated anions are substrates for the MRP. To learn more about MRP-drug interactions, we characterized the binding of MRP to a non-glutathione photoactive quinoline compound (abbreviated, ASA-AQ) (Chapter II). Since MRP mediated multi-drug resistance can be modulated by the anionic quinoline LTD$ sb4$ cysteinyl leukotriene receptor antagonist (MK571), we speculated that other quinoline-based compounds are likely to interact with MRP. In Chapter III, we show that MDR cells that express MRP1 are more resistant to the antimalarial drug, chloroquine. We also show that. chloroquine is a substrate for MRP1 drug efflux. / Taken together, the results of this thesis describe the interactions of MRP1 with a quinoline-based photoactive drug and the antimalarial drug chloroquine.

The aqueous solubility of an active pharmaceutical ingredient (API) is an important property that requires evaluation during early development and prior to formulation of the final product. With general, experimental, solubility testing of different APIs, the question always arises as to whether particle size had been determined beforehand or not. All available literature suggests that particle size, for pharmaceutical powders, does not significantly affect equilibrium solubility. The dissolution rate will differ according to different particle sizes, but the overall results should be identical after equilibrium is established. This study was therefore planned to investigate as to whether different particle size fractions of the same API, dissolving at different rates, would all reach solubility equilibrium within 24 hours. Also, APIs from different solubility classes were investigated, because poorly soluble substances would most likely require a longer period of time to equilibrate. The time period of 24 hours was selected, because many published solubility studies report using that interval and is it the standard for our research group also. Available APIs were selected to determine the influence (if any) of particle size on their equilibrium solubilities and the time required for attaining that status. For the purpose of this investigation, five APIs were selected from compounds at our disposal in-house, ranging from freely soluble to poorly soluble in the order: chloroquine phosphate > pyrazinamide > mefloquine hydrochloride > closantel sodium > roxithromycin. Solubility studies were successfully completed on four of the five APIs selected. For closantel sodium, pyrazinamide and roxithromycin it was demonstrated that the 24 hour test period was sufficient for the attainment of equilibrium solubility, regardless of the particle size fractions tested. Surprisingly, the only API in this study for which 24 hours was an insufficient test period was mefloquine HCl, which was not the least soluble compound tested. Further testing would be required to clarify this anomaly. What was evident from the outcomes of this investigation was that although the ubiquitous 24 hour solubility test may work well in many cases, its suitability should be reviewed on a case-by-case basis and not just for the most poorly soluble compounds. Researchers testing solubility at temperatures lower than 37°C should be especially cautious of using a standardised test period, because equilibrium solubility would take longer to achieve with less energy available to the system. / Thesis (MSc (Pharmaceutics))--North-West University, Potchefstroom Campus, 2013

The aqueous solubility of an active pharmaceutical ingredient (API) is an important property that requires evaluation during early development and prior to formulation of the final product. With general, experimental, solubility testing of different APIs, the question always arises as to whether particle size had been determined beforehand or not. All available literature suggests that particle size, for pharmaceutical powders, does not significantly affect equilibrium solubility. The dissolution rate will differ according to different particle sizes, but the overall results should be identical after equilibrium is established. This study was therefore planned to investigate as to whether different particle size fractions of the same API, dissolving at different rates, would all reach solubility equilibrium within 24 hours. Also, APIs from different solubility classes were investigated, because poorly soluble substances would most likely require a longer period of time to equilibrate. The time period of 24 hours was selected, because many published solubility studies report using that interval and is it the standard for our research group also. Available APIs were selected to determine the influence (if any) of particle size on their equilibrium solubilities and the time required for attaining that status. For the purpose of this investigation, five APIs were selected from compounds at our disposal in-house, ranging from freely soluble to poorly soluble in the order: chloroquine phosphate > pyrazinamide > mefloquine hydrochloride > closantel sodium > roxithromycin. Solubility studies were successfully completed on four of the five APIs selected. For closantel sodium, pyrazinamide and roxithromycin it was demonstrated that the 24 hour test period was sufficient for the attainment of equilibrium solubility, regardless of the particle size fractions tested. Surprisingly, the only API in this study for which 24 hours was an insufficient test period was mefloquine HCl, which was not the least soluble compound tested. Further testing would be required to clarify this anomaly. What was evident from the outcomes of this investigation was that although the ubiquitous 24 hour solubility test may work well in many cases, its suitability should be reviewed on a case-by-case basis and not just for the most poorly soluble compounds. Researchers testing solubility at temperatures lower than 37°C should be especially cautious of using a standardised test period, because equilibrium solubility would take longer to achieve with less energy available to the system. / Thesis (MSc (Pharmaceutics))--North-West University, Potchefstroom Campus, 2013