Client needs and satisfaction in an HIV facility

Health care evaluation serves the purpose of monitoring the quality of health care provided by Health Care Providers (HCP), so that health care services can be provided most effectively and efficiently. Patient satisfaction studies are widely used to assess the quality of outpatient care. A client satisfaction study was conducted at an HIV health care facility in Sydney, Australia during 2007-2008. There were three objectives: 1.) To validate a questionnaire for future determination of client satisfaction in HIV health care facilities. 2.) To identify the levels of satisfaction of clients, and investigate any dissatisfaction and unmet needs towards HIV health care. 3.) To provide recommendations for improving client satisfaction levels in HIV health care. This research used a mixed method approach and consisted of two phases. The first phase was a quantitative survey conducted with 166 clients (both HIV positive and negative) at Albion Street Centre (ASC) using a newly-devised questionnaire. Clients were asked to answer demographic questions, rate their levels of satisfaction with each aspect and each HCP category, and provide suggestions for improvement. Quantitative statistical analysis was conducted to obtain a general view of client satisfaction levels. Dissatisfaction and unmet needs of clients were then investigated in-depth in the second phase of the research through qualitative face-to-face semi-structured interviews. Twenty-two clients (both HIV positive and negative) at ASC were interviewed individually and asked about their attitudes, perceptions, and experiences towards their HCP and the HIV health care services received. Thematic analysis was used to categorise and interpret the qualitative data. More than 90% of the clients were satisfied with most of the aspects covered in the survey, with a mean overall satisfaction score of 84 out of 100. Clients were most iii satisfied with the “technical quality” and “interpersonal manner” of the HCP, and were least satisfied with “waiting time” and “availability of HCP”. The HCP category with which the clients has the highest level of satisfaction was “nurses” (86%), followed by “psychologists” (84%), then “doctors” (83%). Clients who were HIV negative, had a full time job, visited ASC less frequently, or did not possess any type of Health Care Card were more satisfied with the services overall. No common dissatisfaction or unmet needs towards HIV health care service were identified. “Technical quality of HCP” and “the relationship with HCP” were the two most important determinants of client satisfaction, which outweighed the inconvenience contributed by the poor availability of HCP and the location of ASC. The maintenance of “confidentiality/privacy” was shown to be fundamental in HIV health care facilities. The multi-disciplinary nature of ASC increased the degree of convenience and satisfaction level among clients. Suggestions for improvement in client satisfaction levels include increasing the attractiveness of the physical environment and the variety of educational reading materials in the waiting area; introducing beverages, and encouraging clients to be involved in their treatment decisions. Health care administrative staff in particular are reminded not to neglect the importance of the availability of HCP, accessibility, and physical environment when establishing a new HIV health care facility. The mixed method approach (quantitative survey and qualitative interviews) proved beneficial. It increased the validity of the findings by assessing client satisfaction levels using more than one method. This enabled clarification of ambiguities noted in the initial survey through probes used in the interviews, and also allowed investigation of the determinants of client satisfaction through understanding their experiences in HIV health care. Future client satisfaction studies would benefit from using this approach

Differential Bird Responses to Colour Morphs of an Aposematic Leaf Beetle may Affect Variation in Morph Frequencies in Polymorphic Prey Populations

The selection of prey by predators should, theoretically, favour uniformity in the warning signals displayed by unpalatable prey. Nevertheless, some aposematically coloured species are polymorphic. We tested the hypothesis that colour morphs of unpalatable prey differ in the efficacy of their aposematic signal for birds, thereby affecting the selective advantages of these morphs. We used colour morphs (red-and-black light, red-and-black dark and metallic) of the chemically defended leaf beetle Chrysomela lapponica. In laboratory experiments, naïve great tits (Parus major) attacked live beetles of all colour morphs at the same rate. By contrast, wild-caught tits attacked light beetles at first encounter at the same rate as a novel control prey, but significantly avoided both dark and metallic beetles. Beetles of all colour morphs were similarly unpalatable for birds, and about half of the attacked beetles were released unharmed. Avoidance learning was similarly fast for all three leaf beetle morphs. However, in the next-day memory test, the dark beetles were attacked at a greater rate than beetles of two other morphs, indicating their lower memorability. A field experiment suggests that at low C. lapponica population densities, dark beetles have a survival advantage over light beetles, potentially due to the lesser conspicuousness of the dark pattern; however, when the density is high, dark beetles lose this advantage due to the low memorability of their pattern. Thus, the direction of selective bird predation on prey colour morphs may depend on prey density and thereby contribute to temporal shifts in colour morph frequencies following population fluctuations.</p

Surface engineering of silica nanoparticles for oral insulin delivery: characterization and cell toxicity studies

The present work aimed at studying the interaction between insulin and SiNP surfaced with mucoadhesive polymers (chitosan, sodium alginate or polyethylene glycol) and the evaluation of their biocompatibility with HepG2 and Caco-2 cell lines, which mimic in vivo the target of insulin-loaded nanoparticles upon oral administration. Thus, a systematic physicochemical study of the surface-modified insulin-silica nanoparticles (Ins-SiNP) using mucoadhesive polymers has been described. The surfacing of nanoparticle involved the coating of silica nanoparticles (SiNP) with different mucoadhesive polymers, to achieve high contact between the systems and the gut mucosa to enhance the oral insulin bioavailability. SiNP were prepared by a modified Stöber method at room temperature via hydrolysis and condensation of tetraethyl orthosilicate (TEOS). Interaction between insulin and nanoparticles was assessed by differential scanning calorimetry (DSC), X-ray and Fourier-transform infrared (FTIR) studies. The high efficiency of nanoparticles' coating resulted in more stable system. FTIR spectra of insulin-loaded nanoparticles showed amide absorption bands which are characteristic of α-helix content. In general, all developed nanoparticles demonstrated high biocompatible, at the tested concentrations (50-500 μg/mL), revealing no or low toxicity in the two human cancer cell lines (HepG2 and Caco-2). In conclusion, the developed insulin-loaded SiNP surfaced with mucoadhesive polymers demonstrated its added value for oral administration of proteins

Development, physico-chemical and toxicological characterisation of solid lipid nanoparticles for application in breast cancer therapy

Tese de Doutoramento em Genética Molecular ComparativaAs nanopartículas de lípidos sólidos (SLN, do inglês “solid lipid nanoparticles”) são transportadores coloidais de fármacos, constituídos por uma matriz de lípidos sólidos à temperatura corporal e à temperatura ambiente, estabilizados por agentes tensioactivos apropriados. No âmbito da presente tese, estes sistemas foram desenvolvidos com objectivo de administração de fármacos pouco solúveis em água, e para facilitar a administração direccionada a células de cancro. O objectivo deste trabalho consistiu em explorar o potencial das SLN no tratamento da invasão celular de cancro de mama, nomeadamente das células HER2/neu positivas. Foram desenvolvida partículas cuja composição consistiu no Imwitor 900K ou Compritol 888 ATO (como lípidos sólidos), no cetyltrimethylammonium bromide (CTAB) como lípido catiónico/tensioactivo e no Lutrol F68 ou Miranol C32 Ultra como agente tensioactivo. Como método de produção, foi utilizada a homogenização a alta pressão ou a alta velocidade, seguindo-se a optimização das respectivas formulações, as quais foram utilizadas para os estudos posteriores. As SLN foram caracterizadas em termos de distribuição de tamanho médio das partículas, cristalinidade de matriz lipídica sólida e estabilidade durante armazenamento. Foram obtidas SLN com tamanho médio das partículas entre 115 nm e 334 nm e d0.90 inferior a 1 μm. O estado sólido das mesmas foi confirmado por calorimetria diferencial de varrimento e por difracção de raios X. Todas as formulações apresentaram estabilidade adequada ao longo de 5 semanas, quer à temperatura ambiente, quer a 4 °C. Apesar da liofilização com o crioprotector trealose, a estabilidade das SLN não liofilizadas revelou-se bastante superior. A formulação designada como cSLN-C manteve-se estável durante um período mínimo de 12 semanas. As SLN são, em geral, consideradas como transportadores coloidais com baixa toxicidade. Mesmo assim, o efeito das SLN per si tem importância na interpretação da interacção de formulações que contém um fármaco ou um anticorpo com as células. As SLN desenvolvidas neste trabalho não apresentaram toxicidade na concentração de 0,01 mg/ml. Utilizando a concentração de 0,1 mg/ml a viabilidade celular diminuiu dependendo da linha celular utilizada e tempo de exposição. A dose 1,0 mg/ml foi tóxica nas linhas celulares seleccionadas para este trabalho. Dentro destas, MCF-7 (carcinoma de mama, receptor de estrogénio positivo, HER2-neu negativo) foram as mais susceptíveis aos danos causados pelas SLN, as BT-474 (carcinoma mamário, HER2-neu positivo), HepG2 (hepatocarcinoma) e Caco-2 (cólon adenocarcinoma) foram menos susceptíveis em ordem decrescente. A toxicidade das SLN foi causada por disrupção de integridade das membranas celulares. Danos em ácido deoxiribonucléico (ADN) foram detectados por ensaio cometa. Foram reportados poucos danos – quando comparado com controlo sem tratamento (não significativo nas concentrações não tóxicas). Também foram detectados danos em purinas, que não causaram quebras de ADN. Alguns sinais de stress oxidativo foram detectados em células HepG2: a fluorescência de diacetato de diclorofluoresceina (DCFDA) encontrou-se aumentada relativamente aos controlos sem tratamento e aos positivos, verificou-se um aumento da actividade da enzima superóxido dismutase e uma diminuição da actividade de glutationa reductase. Apesar destes sinais de existência de stress oxidativo, os lípidos membranares não foram afectados (determinação como substâncias reactivas ao ácido tiobarbitúrico, TBARS). Estes resultados estão em concordância com poucos danos detectados em ADN (relativamente ao controlo sem tratamento). Os danos causados por stress oxidativo podem ocorrer em células com capacidade antioxidante inferior à das células HepG2. A capacidade de indução de stress oxidativo pode, hipoteticamente, ser vantajosa em veiculação de fármacos quimioterapêuticos, cujo mecanismo de acção exige existência de radicais livres, e pode, parcialmente, contribuir para a melhoria de eficácia destes medicamentos, quando veiculadas em SLN in vitro e in vivo. A Curcumina foi seleccionada como fármaco-modelo com potencial actividade antineoplásica. A baixa solubilidade aquosa, instabilidade em pH alcalino e fotossensibilidade são propriedades que fazem da curcumina um fármaco ideal para a encapsulação em SLN. Contudo, a solubilidade em vários lípidos foi igual ou inferior a 1 %. A baixa solubilidade em lípidos influenciou a capacidade de carga. Em combinação com as limitações atribuídas à toxicidade das SLN, apenas pode ser administrada 10 μg/ml (27 μM) no máximo, uma dose que é insuficiente para observar os efeitos anticancerígenos da curcumina. Um anticorpo anti- HER2/neu foi colocado na superfície das SLN utilizando a interacção streptavidina-biotina. O efeito de complexo anticorpo-SLN foi governado pela toxicidade das próprias SLN. A conjugação com o anticorpo melhorou significativamente a internalização de complexos nas células de cancro mamário. O efeito foi mais marcado em células BT474, HER2/neu positivas. O tratamento com complexo SLN-anticorpo causou uma diminuição de viabilidade celular das linhas de cancro de mama superior ao efeito das partículas isoladas ou do anticorpo isolado.Solid lipid nanoparticles (SLN) are colloidal carriers consisting of lipid cores that are solid at body and room temperature dispersed in aqueous phase and stabilized by suitable surfactant. They were developed to improve drug delivery of drugs that are poorly soluble in water and to enable targeted delivery to cancer cells. The aim of this work was to explore the potential of SLN in treatment of breast cancer cell invasion, namely HER2/neu positive breast cancer cells. A series of SLN composed of Imwitor 900K or Compritol 888 ATO as solid lipid, cetyltrimethylammonium bromide (CTAB) as cationic lipid/surfactant and Lutrol F68 or Miranol C32 Ultra as surfactants was developed. Optimized high shear homogenisation of high pressure homogenisation were used as preparation methods. SLN were characterized in terms of particle size distibution, lipid core crystalinity and storage stability. SLN with mean particle size between 115 nm and 334 nm and d0.50 below 0.5 μm were obtained; the crystalline state of lipid cores was confirmed by differential scanning calorimetry and X-ray diffraction. All SLN were stable for at least 4 weeks at room temperature and 4 °C, which was superior to stability of the same SLN freezedryed with trehalose. Compritol-composed SLN were stable over 12 weeks. SLN are in general considered as safe colloidal carriers, their effect on living cells however cannot be neglected when interpreting the studies of interaction of drug-loaded and/or targeted SLN with cells. SLN developed in this work were non-toxic to living cells at a dose 0.01 mg/ml; cell viability was reduced to various extent at 0.1 mg/ml depending on cell line and time of exposure and at 1.0 mg/ml the SLN were toxic to the selected cell lines. Among the used cell lines, MCF-7 cells (breast carcinoma, estrogen receptor positive, Her2/neu negative) were the most susceptible to our SLN, followed by BT-474 (breast carcinoma, HER2/neu positive), HepG2 (hepatocarcinoma) and Caco-2 (colorectal carcinoma) cells. Toxicity of SLN was caused mostly by disruption of membrane integrity. DNA damage was examined by comet assay and was detected in a limited extent, compared to untreated controls (not significant at non-toxic concentrations). Damage to purine bases that did not directly lead to DNA strand breaks was also detected. Some signs of oxidative stress was detected in HepG2 cells: dichlorofluorescein-diacetate (DCFDA) assay revealed increase in free radicals content compared to untreated and positive controls, activity of superoxid dismutase was found increased and activity of glutathion reductase was drastically decreased. Despite these signs of oxidative stress, membrane lipids were not affected – as determined by thiobarbituric acid reactive species (TBARS) determination. This finding is in line with only slightly increased DNA strand breaks (compared to untreated control). Damage caused by oxidative stress after SLN exposure may however occur in cells with lower antioxidant capacity than HepG2 cells. The capacity to induce oxidative stress can hypotethically be beneficial for delivery of chemotherapeutic drugs – that require some free radical increase for their action – and may partly explain many reports on SLN improving efficiency of chemotherapeutics in vitro and in vivo. Curcumin was selected as model drug with potential chemotherapeutic effect. Its low solubility, instability at alkaline pH and light make it an ideal candidate for encapsulation into SLN. Unfortunately, its solubility in solid lipids was limited to 1% (w/w) and to lipid mixtures containing either monoacylglycerides or polyethylenglycol. This affected the resulting drug loading, which together with limitations by SLN toxicity only enabled use of dose equal or lower than 10 μg/ml (27μM) of curcumin – i.e. doses lower than those at which anticancer effects were observed. An antiHER2/neu antibody was attached to SLN surface via streptavidin-biotin binding. The effect of targeted complex was influenced mostly by the toxicity of SLN alone, but at non-toxic dose of SLN a synergistic effect between SLN and the antibody was observed. The antibody improved significantly cell internalization into breast cancer cells, mostly in HER2/neu positive BT-474 cells but to some extent also in MCF-7 cells. Exposure to targeted SLN leads to cell viabilities lower than when exposed to antibody alone or SLN alone