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1.
J Health Econ ; 91: 102800, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37562282

RESUMEN

Extreme heat negatively impacts cognition, learning, and task performance. With increasing global temperatures, workers may therefore be at increased risk of work-related injuries and illness. This study estimates the effects of temperature on worker health using records spanning 1985-2020 from an Australian mandatory insurance scheme. High temperatures are found to cause significantly more claims, particularly among manual workers in outdoor-based industries. These adverse effects have not diminished across time, with the largest effect observed for the 2015-2020 period, indicating increasing vulnerability to heat. Within occupations, the workers most adversely affected by heat are female, older-aged and higher-earning. Finally, results from firm-level panel analyses show that the percentage increase in claims on hot days is largest at "safer" firms.


Asunto(s)
Exposición Profesional , Traumatismos Ocupacionales , Humanos , Femenino , Masculino , Calor , Australia/epidemiología , Exposición Profesional/efectos adversos , Temperatura
2.
BMC Plant Biol ; 23(1): 162, 2023 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-36964494

RESUMEN

BACKGROUND: Terminalia ivorensis (TI) is used in West African ethnomedicine for the treatment of conditions including ulcers, malaria and wounds. Despite its widespread use, the phytochemical profile of TI remains largely undetermined. This research investigated the effects of extraction method, season, and storage conditions on the phytochemical composition of TI to contribute towards understanding the potential benefits. METHODS: TI bark was collected in September 2014, September 2018 and February 2018 during the rainy or dry seasons in Eastern Region, Ghana. Samples were extracted sequentially with organic solvents (petroleum ether, chloroform, ethyl acetate and ethanol) or using water (traditional). Metabolites were identified by liquid chromatography-mass spectrometry/mass spectrometry and compared statistically by ANOVA. RESULTS: A total of 82 different phytochemicals were identified across all samples. A greater yield of the major phytochemicals (44%, p < 0.05) was obtained by water as compared with organic extraction. There was also a higher concentration of metabolites present in cold (63%, p < 0.05) compared with hot water extraction. A significantly (p < 0.05) higher number of phytochemicals were identified from TI collected in the dry (85%) compared to the rainy season (69%). TI bark stored for four years retained 84% of the major phytochemicals. CONCLUSION: This work provides important information on composition and how this is modified by growing conditions, storage and method of extraction informing progress on the development of TI as a prophylactic formulation or medicine.


Asunto(s)
Extractos Vegetales , Terminalia , Extractos Vegetales/química , Terminalia/química , Estaciones del Año , Fitoquímicos/análisis , Solventes/química , Agua
3.
Health Econ ; 31(9): 2072-2089, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35770835

RESUMEN

Billions of people live in urban poverty, with many forced to reside in disaster-prone areas. Research suggests that such disasters harm child nutrition and increase adult morbidity. However, little is known about impacts on mental health, particularly of people living in slums. In this paper we estimate the effects of flood disasters on the mental and physical health of poor adults and children in urban Indonesia. Our data come from the Indonesia Family Life Survey and new surveys of informal settlement residents. We find that urban poor populations experience increases in acute morbidities and depressive symptoms following floods, that the negative mental health effects last longer, and that the urban wealthy show no health effects from flood exposure. Further analysis suggests that worse economic outcomes may be partly responsible. Overall, the results provide a more nuanced understanding of the morbidities experienced by populations most vulnerable to increased disaster occurrence.


Asunto(s)
Depresión , Inundaciones , Pobreza , Población Urbana , Poblaciones Vulnerables , Adulto , Niño , Depresión/epidemiología , Depresión/etiología , Desastres , Humanos , Salud Mental , Morbilidad
4.
Genomics ; 112(2): 1795-1803, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31678594

RESUMEN

AIM: To determine the association of peroxisome proliferator activated receptor gamma coactivator 1 Gly482Ser variant with components of metabolic syndrome. MATERIALS AND METHODS: A systematic search was carried out using Web of Science, PubMed, EMBASE and the Cochrane library using the key words: Peroxisome proliferator activator receptor gamma coactivator 1, PPARGC1A, PGC-1, PGC-1alpha, and PGC1alpha alone or with polymorphism, Gly482Ser and rs8192678. RESULTS: Data from 19 articles generated 28 separate data sets. Under the recessive model fasting plasma glucose was significantly lower in AA genotypes when compared to GG + GA in the total sample group and in non-Asian group (p < .001). The AA genotype showed significantly lower levels of total cholesterol compared to GG + GA genotype using the recessive model with the non-Asian group (p < .05). Under the dominant model, body mass index of the GG genotype was significantly higher in Asian subgroups (p < .05). CONCLUSION: PPARGC1A Gly482Ser variant impacts differently in Asian population groups.


Asunto(s)
Síndrome Metabólico/genética , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/genética , Polimorfismo de Nucleótido Simple , Adulto , Pueblo Asiatico/genética , Colesterol/sangre , Femenino , Humanos , Masculino , Síndrome Metabólico/sangre , Persona de Mediana Edad
5.
J Neurotrauma ; 36(17): 2541-2548, 2019 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-30907230

RESUMEN

The EPO-TBI multi-national randomized controlled trial found that erythropoietin (EPO), when compared to placebo, did not affect 6-month neurological outcome, but reduced illness severity-adjusted mortality in patients with traumatic brain injury (TBI), making the cost-effectiveness of EPO in TBI uncertain. The current study uses patient-level data from the EPO-TBI trial to evaluate the cost-effectiveness of EPO in patients with moderate or severe TBI from the healthcare payers' perspective. We addressed the issue of transferability in multi-national trials by estimating costs and effects for specific geographical regions of the study (Australia/New Zealand, Europe, and Saudi Arabia). Unadjusted mean quality-adjusted life-years (QALYs; 95% confidence interval [CI]) at 6 months were 0.027 (0.020-0.034; p < 0.001) higher in the EPO group, with an adjusted QALY increment of 0.014 (0.000-0.028; p = 0.04). Mean unadjusted costs (95% CI) were $US5668 (-9191 to -2144; p = 0.002) lower in the treatment group; controlling for baseline IMPACT-TBI score and regional heterogeneity reduced this difference to $2377 (-12,446 to 7693; p = 0.64). For a willingness-to-pay threshold of $US50,000 per QALY, 71.8% of replications were considered cost-effective. Therefore, we did not find evidence that EPO was significantly cost-effective in the treatment of moderate or severe TBI at 6-month follow-up.


Asunto(s)
Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Eritropoyetina/economía , Eritropoyetina/uso terapéutico , Fármacos Neuroprotectores/economía , Fármacos Neuroprotectores/uso terapéutico , Adulto , Lesiones Traumáticas del Encéfalo/mortalidad , Análisis Costo-Beneficio , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Aceptación de la Atención de Salud/estadística & datos numéricos , Años de Vida Ajustados por Calidad de Vida , Resultado del Tratamiento , Adulto Joven
6.
Food Chem Toxicol ; 121: 283-296, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30208301

RESUMEN

Non-alcoholic fatty liver disease (NAFLD) is often linked with impaired hepatic autophagy. Here, we studied the alterations in hepatocellular autophagy by high cholesterol and high-fat diet (HC-HF) diet in C57BL/6J mice, and by palmitic acid (PA), in AML-12 and HepG2 cells. Further, we analysed role of Trigonelline (TG), a plant alkaloid, in preventing NAFLD, by modulating autophagy. For this, C57BL/6J mice were fed with Standard Chow (SC) or HC-HF diet, with and without TG for 16 weeks. In-vitro; AML-12 cells and HepG2 cells, were exposed to PA with and without TG, for 24 h. Cellular events related to autophagy, lipogenesis, and lipo-toxicity were studied. The HC-HF diet fed mice showed hepatic autophagy blockade, increased triglycerides and steatosis. PA exposure to AML-12 cells and HepG2 cells induced impaired autophagy, ER stress, resulting in lipotoxicity. TG treatment in HC-HF fed mice, restored hepatic autophagy, and prevented steatosis. TG treated AML-12, and HepG2 cells exposed to PA showed autophagy restoration, and reduced lipotoxicity, however, these effects were diminished in Atg7-/- HepG2 cells, and in the presence of chloroquine. This study shows that HC-HF diet-induced impaired autophagy, and steatosis is prevented by TG, which attributes to its novel mechanism in treating NAFLD.


Asunto(s)
Alcaloides/farmacología , Autofagia/efectos de los fármacos , Colesterol/administración & dosificación , Dieta Alta en Grasa/efectos adversos , Hígado Graso/inducido químicamente , Alimentación Animal/análisis , Animales , Proteína 7 Relacionada con la Autofagia/genética , Proteína 7 Relacionada con la Autofagia/metabolismo , Línea Celular , Supervivencia Celular/efectos de los fármacos , Hígado Graso/prevención & control , Silenciador del Gen , Humanos , Resistencia a la Insulina , Metabolismo de los Lípidos/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Regulación hacia Arriba , Aumento de Peso
7.
Soc Sci Med ; 190: 247-255, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28881208

RESUMEN

Systematic differences in the ways that people use and interpret response categories (differential item functioning, DIF) can introduce bias when using self-assessments to compare health or quality of life across heterogeneous groups. This paper reports on an exploratory analysis involving the use of anchoring vignettes to identify DIF in a commonly used measure for assessing health-related quality of life - namely the EQ-5D. Using data from a bespoke (i.e. custom) survey that recruited a representative sample of 4300 respondents from the general Australian population in 2014 and 2015, we find that the assumptions of response consistency (RC) and vignette equivalence (VE) hold in a sub-sample of respondents aged 55-65 years (n = 914), which demonstrates that vignettes can appropriately identify DIF in EQ-5D reporting for this age group. We find that the EQ-5D is indeed subject to DIF, and that failure to account for DIF can lead to conclusions that are misleading when using the instrument to compare health or quality of life across heterogeneous groups. We also provide several important insights in terms of the identifying assumptions of RC and VE. We conclude that the implications of DIF could be of considerable importance, not only for outcomes research, but for funding decisions in healthcare more broadly given the strong reliance on patient-reported outcome measures in economic evaluations for health technology assessment.


Asunto(s)
Actividades Cotidianas/psicología , Estado de Salud , Calidad de Vida/psicología , Autoinforme/normas , Pesos y Medidas/instrumentación , Adulto , Anciano , Australia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios
8.
Health Econ ; 26(3): 387-394, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-26756822

RESUMEN

This paper discusses two types of response-scale heterogeneity, which may impact upon the EQ-5D. Response-scale heterogeneity in reporting occurs when individuals systematically differ in their use of response scales when responding to self-assessments. This type of heterogeneity is widely observed in relation to other self-assessed measures but is often overlooked with regard to the EQ-5D. Analogous to this, preference elicitation involving the EQ-5D could be subject to a similar type of heterogeneity, where variations across respondents may occur in the interpretations of the levels (response categories) being valued. This response-scale heterogeneity in preference elicitation may differ from variations in preferences for health states, which have been observed in the literature. This paper explores what these forms of response-scale heterogeneity may mean for the EQ-5D and the potential implications for researchers who rely on the instrument as a measure of health and quality of life. We identify situations where they are likely to be problematic and present potential avenues for overcoming these issues. Copyright © 2016 John Wiley & Sons, Ltd.


Asunto(s)
Estado de Salud , Autoevaluación (Psicología) , Encuestas y Cuestionarios , Humanos , Modelos Estadísticos , Años de Vida Ajustados por Calidad de Vida
10.
Int J Pharm ; 515(1-2): 575-582, 2016 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-27771488

RESUMEN

Nephropathic cystinosis is a rare autosomal recessive disease characterised by raised lysosomal levels of cystine in the cells of all organs. It is treated by regular administration of the aminothiol, cysteamine. Corneal crystal deposition is one of the most troublesome complications affecting patients and requires the hourly administration of cysteamine eye drops. In an attempt to reduce this frequency and improve the treatment, the preformulation and evaluation of cysteamine containing gels is reported. Suitability for ophthalmic delivery was determined by analysis of rheology, bioadhesion, dissolution and stability. The results demonstrated that three polymers were suitable for ophthalmic delivery of cysteamine; namely sodium hyaluronate, hydroxyethyl cellulose and carbomer 934. Sodium hyaluronate displayed optimum performance in the preformulation tests, being pseudoplastic (reduction in apparent viscosity under increasing shear rate), bioadhesive, releasing cysteamine over 40min and displaying stability over time. In conclusion these results offer the possibility to formulate cysteamine in an ocular applicable gel formulation.


Asunto(s)
Córnea/efectos de los fármacos , Cisteamina/química , Cisteamina/farmacología , Oftalmopatías/tratamiento farmacológico , Geles/química , Geles/farmacología , Resinas Acrílicas/química , Animales , Bovinos , Celulosa/análogos & derivados , Celulosa/química , Química Farmacéutica/métodos , Cistinosis/complicaciones , Sistemas de Liberación de Medicamentos/métodos , Oftalmopatías/etiología , Humanos , Ácido Hialurónico/química , Soluciones Oftálmicas/química , Soluciones Oftálmicas/farmacología , Polímeros/química , Reología , Solubilidad
11.
Pharmacoeconomics ; 34(2): 139-54, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26547307

RESUMEN

There is a growing appetite for large complex databases that integrate a range of personal, socio-demographic, health, genetic and financial information on individuals. It has been argued that 'Big Data' will provide the necessary catalyst to advance both biomedical research and health economics and outcomes research. However, it is important that we do not succumb to being data rich but information poor. This paper discusses the benefits and challenges of building Big Data, analysing Big Data and making appropriate inferences in order to advance cancer care, using Cancer 2015 (a prospective, longitudinal, genomic cohort study in Victoria, Australia) as a case study. Cancer 2015 has been linked to State and Commonwealth reimbursement databases that have known limitations. This partly reflects the funding arrangements in Australia, a country with both public and private provision, including public funding of private healthcare, and partly the legislative frameworks that govern data linkage. Additionally, linkage is not without time delays and, as such, achieving a contemporaneous database is challenging. Despite these limitations, there is clear value in using linked data and creating Big Data. This paper describes the linked Cancer 2015 dataset, discusses estimation issues given the nature of the data and presents panel regression results that allow us to make possible inferences regarding which patient, disease, genomic and treatment characteristics explain variation in health expenditure.


Asunto(s)
Bases de Datos Factuales/estadística & datos numéricos , Economía Médica , Gastos en Salud/estadística & datos numéricos , Neoplasias/terapia , Adulto , Anciano , Anciano de 80 o más Años , Australia , Estudios de Cohortes , Femenino , Genómica , Humanos , Estudios Longitudinales , Masculino , Registro Médico Coordinado , Persona de Mediana Edad , Neoplasias/economía , Evaluación de Resultado en la Atención de Salud/métodos , Estudios Prospectivos
12.
Int J Pharm ; 490(1-2): 1-8, 2015 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-25980731

RESUMEN

A modified hen's egg chorioallantoic membrane (HET-CAM) test has been developed, combining ImageJ analysis with Adobe(®) Photoshop(®). The irritation potential of an ophthalmic medicine can be quantified using this method, by monitoring damage to blood vessels. The evaluation of cysteamine containing hyaluronate gel is reported. The results demonstrated that the novel gel formulation is non-irritant to the ocular tissues, in line with saline solution (negative control). In conclusion, the modification of the established HET-CAM test can quantify the damage to minute blood vessels. These results offer the possibility to formulate cysteamine in an ocular applicable gel formulation.


Asunto(s)
Alginatos/efectos adversos , Cisteamina/efectos adversos , Ojo/efectos de los fármacos , Ácido Hialurónico/efectos adversos , Irritantes/efectos adversos , Alternativas a las Pruebas en Animales/métodos , Animales , Vasos Sanguíneos/efectos de los fármacos , Química Farmacéutica/métodos , Pollos , Membrana Corioalantoides , Femenino
13.
Health Policy ; 119(5): 620-7, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25724823

RESUMEN

This paper assesses whether the concession card, which offers discounted out-of-pocket costs for prescription medicines in Australia, affects discontinuation and adherence to statin therapy. The analysis uses data from the Australian Hypertension and Absolute Risk Study (AusHEART), which involves patients aged 55 years and over who visited a GP between April and June 2008. Socioeconomic and clinical information was collected and linked to administrative data on pharmaceutical use. Patients without a concession card were 63% more likely (hazard ratio (HR) 95% confidence interval (CI): 1.14-2.33) to discontinue and 60% (odds ratio (OR) CI: 1.04-2.44) more likely to fail to adhere to therapy compared to concessional patients. Smokers were 2.12 (HR CI: 1.39-3.22) times more likely to discontinue use and 2.23 (OR CI: 1.35-3.71) times more likely to fail to adhere compared to non-smokers. Patients who had recently initiated statin medication were also 2.28 (HR CI: 1.22-4.28) times more likely to discontinue use. In conclusion, higher copayments act as a disincentive for persistent and adherent use of statin medication.


Asunto(s)
Deducibles y Coseguros , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Hipertensión/tratamiento farmacológico , Reembolso de Seguro de Salud/economía , Cumplimiento de la Medicación , Anciano , Australia , Femenino , Gastos en Salud , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/economía , Masculino , Persona de Mediana Edad
14.
Int J Pharm ; 457(1): 40-9, 2013 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-24055598

RESUMEN

Reduced oxygen tension combined with high glucose concentration leads to chronic wounds in diabetic patients. Delayed wound healing is due in part to impaired angiogenesis as a result of reduced endothelial cell migration. Topical applications, in the form of sterile lyophilised wafers hold promise for the treatment of chronic diabetic wounds. In this study wafers containing silymarin were prepared using xanthan gum and sterilised with 25 and 40 kGy gamma radiation. The rheological properties of xanthan gels, before and after lyophilisation, were measured and it was concluded that an increased dose of gamma rays (40 kGy) increased the viscosity coefficient and yield stress of silymarin wafers. HPLC analysis indicated that 89-90% of silymarin was retained in the wafers after irradiation. Dermal microvascular cell migration studies in the presence of high glucose and reduced oxygen tension levels, using novel radial migration and wound healing assays developed 'in house', were also undertaken. Silymarin, when formulated as a lyophilised wafer, successfully retained its ability to overcome the high glucose induced reduction in endothelial cell migration.


Asunto(s)
Antioxidantes/administración & dosificación , Sistemas de Liberación de Medicamentos , Células Endoteliales/efectos de los fármacos , Silimarina/administración & dosificación , Movimiento Celular/efectos de los fármacos , Células Endoteliales/fisiología , Glucosa , Humanos
15.
Microvasc Res ; 88: 61-9, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23562913

RESUMEN

Delayed wound healing is characteristic of those affected by both Type 1 and Type 2 diabetes. We have developed a novel assay to investigate endothelial cell migration using primary microvascular endothelial cells of dermal origin. Endothelial cell migration was determined using defined monolayers of cells. Net migration or migration at a wounded edge was recorded after 24 or 48 h following incubation in either 20% or 5% oxygen in combination with either 5 mmol/l or 20 mmol/l glucose. Specific intracellular inhibitors of p42/44 MAPK, Pi3 kinase and protein kinase CßII were used. Hypoxia inducible factor type 1 alpha protein was detected using immunocytochemical staining. Cell migration was increased in the presence of hypoxia and decreased with high glucose concentration (p<0.001). The newly developed wound healing assay revealed that re-endothelialisation occurred at a greater rate (p<0.001) than endothelialisation. Inhibition of p42/44MAPK significantly reduced endothelial cell migration at both the intact and the wounded edge in 20 mmol/l glucose but not 5 mmol/l glucose. Inhibition of Pi3 kinase significantly (p<0.001) reduced migration in all test conditions, while inhibition of PKCß restored glucose mediated impaired migration (p>0.05). HIF-1α protein levels did not significantly reduce in the presence of a PKCß inhibitor at the wounded edge of cells in 20 mmol/l glucose. In conclusion, we have established a novel assay to determine endothelial cell migration that is robust and reproducible. Impaired cell migration mediated by high glucose concentration was restored using an inhibitor of the PKCßII pathway which correlated with an increase in the level of HIF1α protein.


Asunto(s)
Glucosa/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Oxígeno/metabolismo , Proteína Quinasa C beta/metabolismo , Cicatrización de Heridas , Movimiento Celular , Células Endoteliales/citología , Endotelio Vascular/citología , Humanos , Hipoxia , Microcirculación , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Transducción de Señal , Factores de Tiempo
16.
Med J Aust ; 197(11): 625-30, 2012 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-23230933

RESUMEN

OBJECTIVE: To use patient-level data, clinical information and linked Medicare records to assess the distribution of benefits (rebates) across income groups, including benefits relating to chronic conditions such as the Chronic Disease Dental Scheme (CDDS). DESIGN, SETTING AND PARTICIPANTS: Nationally representative, cluster-stratified survey (the Australian Hypertension and Absolute Risk Study) involving 322 general practitioners who each collected clinical data on 15-20 patients aged≥55,2012s who presented between 1 April 2008 and 30 June 2008 and who consented to have their information linked with Medicare administrative records over 12 months. MAIN OUTCOME MEASURES: Distribution of total out-of-hospital Medicare expenditure quantified using concentration indices and determinants of use calculated by odds ratios. RESULTS: There were 2862 patients in the study. After controlling for need, the concentration index for overall funding was slightly progressive (pro-poor) at -0.008 (95% CI, -0.009 to -0.008). Medicare expenditure on chronic care-related services consistently contributed to progressivity of the overall scheme, particularly services under the CDDS with a need-adjusted concentration index of -0.205 (95% CI, -0.208 to -0.201). Uptake of chronic care items varied by locality and comorbid conditions (there was greater uptake by patients with one or more comorbid conditions). CONCLUSIONS: Chronic care items, particularly dental items, have primarily been used by individuals from lower income households. Uptake of chronic care items contributes to the overall progressivity of Medicare.


Asunto(s)
Gastos en Salud/estadística & datos numéricos , Necesidades y Demandas de Servicios de Salud/economía , Renta/estadística & datos numéricos , Cuidados a Largo Plazo/economía , Medicare/economía , Anciano , Anciano de 80 o más Años , Australia , Enfermedad Crónica , Femenino , Médicos Generales , Humanos , Masculino , Medicare/estadística & datos numéricos , Persona de Mediana Edad , Estados Unidos
17.
Bioorg Med Chem ; 19(11): 3492-6, 2011 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-21536447

RESUMEN

As part of our continuing work to obtain new pro-drugs for the treatment of nephropathic cystinosis, a number of glutaric and succinic acid derivatives of cystamine have been designed, synthesised and biologically evaluated in vitro. These compounds have been designed as odourless and tasteless pro-drugs which will release multiple molecules of cysteamine upon administration. All of the synthesised compounds evaluated in this study were non-cytotoxic and displayed a greater ability than cysteamine to deplete the levels of cystine in cultured fibroblasts.


Asunto(s)
Cistamina/análogos & derivados , Síndrome Nefrótico/tratamiento farmacológico , Profármacos/síntesis química , Cistamina/uso terapéutico , Cistamina/toxicidad , Cistinosis , Síndrome de Fanconi , Fibroblastos/efectos de los fármacos , Glutaratos/química , Humanos , Profármacos/uso terapéutico , Profármacos/toxicidad , Ácido Succínico/química
18.
Bioorg Med Chem Lett ; 21(8): 2502-4, 2011 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-21397500

RESUMEN

Nephropathic cystinosis is a rare autosomal recessive disease characterised by raised intracellular levels of the amino acid, cystine. If untreated, the disease, progressively deteriorates towards end stage renal disease (ESRD) at the end of the first decade. The disease is caused by a defect in the lysosomal transport mechanism for cystine. The treatment of choice is the aminothiol cysteamine which acts as a lysine mimic. However, cysteamine possesses an offensive taste and smell and irritates the gastrointestinal tract leading to nausea and vomiting following administration. Furthermore, the rapid metabolism of cysteamine requires oral administration every 6 h for life, in consequence, the patient compliance is poor. As part of our continuing work to obtain new pro-drugs for the treatment of this genetic disease, we have synthesised a folate derivative of cystamine, the disulfide derivative of cysteamine. This new pro-drug was non cytotoxic, showed greater ability to deplete intralysosomal cystine than the current treatment, and, in fact has been the most effective reducer of intralysosomal cystine discovered in our laboratories to date.


Asunto(s)
Cistamina/química , Profármacos/química , Administración Oral , Línea Celular , Cistamina/farmacocinética , Cistamina/uso terapéutico , Cistinosis , Síndrome de Fanconi , Humanos , Síndrome Nefrótico/tratamiento farmacológico , Profármacos/farmacocinética , Profármacos/uso terapéutico
19.
Pharm Res ; 28(4): 886-96, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21213024

RESUMEN

PURPOSE: The influence of polymer architecture on cellular uptake and transport across Caco-2 cells of novel amphiphilic polyelectrolyte-insulin nanocomplexes was investigated. METHOD: Polyallylamine (PAA) (15 kDa) was grafted with palmitoyl chains (Pa) and subsequently modified with quaternary ammonium moieties (QPa). These two amphiphilic polyelectrolytes (APs) were tagged with rhodamine, and their uptake by Caco-2 cells or their polyelectrolyte complexes (PECs) with fluorescein isothiocyanate-insulin (FITC-insulin) uptake was investigated using fluorescence microscopy. The integrity of the monolayer was determined by measurement of transepithelial electrical resistance (TEER), and insulin transport across the monolayers was determined. RESULT: Pa and insulin were co-localised in cell membranes, while QPa complexes were found within the cytoplasm. QPa complex uptake was not affected by calcium, cytochalasin D or nocodazole. Uptake was reduced by co-incubation with sodium azide, an active transport inhibitor. Both polymers opened tight junctions reversibly, and insulin transport through monolayers increased when QPa or Pa was used. CONCLUSION: These APs have been shown to be taken up by Caco-2 cells and reversibly open tight cell junctions. Further work is required to optimise these formulations with a view to maximising their potential to facilitate oral delivery of insulin.


Asunto(s)
Electrólitos/química , Hipoglucemiantes/administración & dosificación , Insulina/administración & dosificación , Nanoconjugados/química , Tensoactivos/química , Administración Oral , Transporte Biológico , Células CACO-2 , Técnicas de Cultivo de Célula , Membrana Celular/metabolismo , Membrana Celular/ultraestructura , Humanos , Hipoglucemiantes/química , Hipoglucemiantes/farmacocinética , Insulina/química , Insulina/farmacocinética , Microscopía Electrónica de Transmisión , Microscopía Fluorescente , Ácidos Palmíticos/química , Poliaminas/química , Succinimidas/química , Trometamina/química
20.
Bioorg Med Chem Lett ; 21(1): 45-7, 2011 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-21147534

RESUMEN

The genetic disease, nephropathic cystinosis is characterized by lysosomal accumulation of the amino acid cystine. Crystallization of cystine in affected organs, if untreated, results in mortality of the affected individuals by their middle to late teens. The only approved treatment for cystinosis is administration of cysteamine. However, cysteamine is associated with an offending odor and taste and this, coupled to a rapid first pass metabolism and a 6h dosing regimen, suggest a clear need to improve the therapy. A number of PEGylated derivatives of cystamine, the disulfide counterpart of cysteamine, have been synthesised and evaluated in cultured cystinotic fibroblasts for toxicity and efficacy. All of the tested compounds were non-cytotoxic and displayed a remarkable depletion of intralysosomal cystine.


Asunto(s)
Cistamina/análogos & derivados , Polietilenglicoles/química , Células Cultivadas , Cistamina/uso terapéutico , Cistamina/toxicidad , Cistinosis , Síndrome de Fanconi , Fibroblastos/efectos de los fármacos , Humanos , Síndrome Nefrótico/tratamiento farmacológico , Profármacos/química , Profármacos/uso terapéutico , Profármacos/toxicidad
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