RESUMEN
The oral K+-sparing diuretic amiloride shows anti-cancer side-activities in multiple rodent models. These effects appear to arise, at least in part, through moderate inhibition of the urokinase-type plasminogen activator (uPA, Kiâ¯=â¯2.4⯵M), a pro-metastatic trypsin-like serine protease that is upregulated in many aggressive solid malignancies. In applying the selective optimization of side-activity (SOSA) approach, a focused library of twenty two 6-substituted amiloride derivatives were prepared, with multiple examples displaying uPA inhibitory potencies in the nM range. X-ray co-crystal structures revealed that the potency increases relative to amiloride arise from increased occupancy of uPA's S1ß subsite by the appended 6-substituents. Leading compounds were shown to have high selectivity over related trypsin-like serine proteases and no diuretic or anti-kaliuretic effects in rats. Compound 15 showed anti-metastatic effects in a xenografted mouse model of late-stage lung metastasis.
Asunto(s)
Amilorida/análogos & derivados , Amilorida/uso terapéutico , Diuréticos/uso terapéutico , Metástasis de la Neoplasia/tratamiento farmacológico , Activador de Plasminógeno de Tipo Uroquinasa/antagonistas & inhibidores , Amilorida/farmacología , Diuréticos/farmacología , Humanos , Relación Estructura-ActividadRESUMEN
BACKGROUND: Translationally controlled tumour protein TCTP is an anti-apoptotic protein frequently overexpressed in cancers, where high levels are often associated with poor patient outcome. TCTP may be involved in protecting cancer cells against the cytotoxic action of anti-cancer drugs. Here we study the early increase of TCTP levels in human colorectal cancer (CRC) and the regulation of TCTP expression in HCT116 colon cancer cells, in response to treatment with the anti-cancer drugs 5-FU and oxaliplatin. METHODS: Using immunohistochemistry, we assessed TCTP levels in surgical samples from adenomas and adenocarcinomas of the colon, compared to normal colon tissue. We also studied the regulation of TCTP in HCT116 colon cancer cells in response to 5-FU and oxaliplatin by western blotting. TCTP mRNA levels were assessed by RT-qPCR. We used mTOR kinase inhibitors to demonstrate mTOR-dependent translational regulation of TCTP under these conditions. Employing the Real-Time Cell Analysis (RTCA) System and the MTS assay, we investigated the effect of TCTP-knockdown on the sensitivity of HCT116 cells to the anti-cancer drugs 5-FU and oxaliplatin. RESULTS: 1. TCTP levels are significantly increased in colon adenomas and adenocarcinomas, compared to normal colon tissue. 2. TCTP protein levels are about 4-fold upregulated in HCT116 colon cancer cells, in response to 5-FU and oxaliplatin treatment, whereas TCTP mRNA levels are down regulated. 3. mTOR kinase inhibitors prevented the up-regulation of TCTP protein, indicating that TCTP is translationally regulated through the mTOR complex 1 signalling pathway under these conditions. 4. Using two cellular assay systems, we demonstrated that TCTP-knockdown sensitises HCT116 cells to the cytotoxicity caused by 5-FU and oxaliplatin. CONCLUSIONS: Our results demonstrate that TCTP levels increase significantly in the early stages of CRC development. In colon cancer cells, expression of this protein is largely upregulated during treatment with the DNA-damaging anti-cancer drugs 5-FU and oxaliplatin, as part of the cellular stress response. TCTP may thus contribute to the development of anti-cancer drug resistance. These findings indicate that TCTP might be suitable as a biomarker and that combinatorial treatment using 5-FU/oxaliplatin, together with mTOR kinase inhibitors, could be a route to preventing the development of resistance to these drugs.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias Colorrectales/metabolismo , Resistencia a Antineoplásicos/efectos de los fármacos , Fluorouracilo/farmacología , Compuestos Organoplatinos/farmacología , Biomarcadores de Tumor/genética , Carcinogénesis/metabolismo , Carcinogénesis/patología , Muerte Celular/efectos de los fármacos , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Resistencia a Antineoplásicos/genética , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Células HCT116 , Humanos , Diana Mecanicista del Complejo 1 de la Rapamicina , Complejos Multiproteicos/metabolismo , Oxaliplatino , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Proteína Tumoral Controlada Traslacionalmente 1RESUMEN
This systematic review investigated the practices that support and hinder the recovery and healing of communities and the environments within which they live, following climate-related environmental disasters. Although the literature focused on recovery is dominated by interventions aimed at the individual and their mental health, a thematic analysis of thirty-six studies established a range of practices that enhance collective recovery and healing. Four narratives were identified from the findings highlighting key practices: (1) collective and community-led recovery; (2) recognising the criticality of context, place, and identity; (3) adopting a holistic conception of well-being and Country-centred practices; and (4) decolonising and Indigenising the literature. This study details recommendations for research and practice. First Nations' knowledges and healing practices need to be recognised and harnessed in climate-related environmental disaster recovery. Community-led interventions harness local knowledge, networks, and expertise, which improves the dissemination of resources and enables recovery efforts to be tailored to the specific needs of communities.
Asunto(s)
Desastres Naturales , HumanosRESUMEN
BACKGROUND: People with chronic kidney disease are often multimorbid and have complex psychosocial needs. For health professionals to deliver holistic, person-centred care to individuals and their carers living with this multifaceted disease, they are required to communicate complex information and problem solve in a multifactorial health and disease context. OBJECTIVES: To explore the perspectives and experiences of tertiary care multidisciplinary team members and primary care providers of health care to people with chronic kidney disease; identify opportunities to innovate and improve the coordinated delivery of health services. DESIGN: The qualitative study design used purposive sampling to recruit 39 health professionals, working in the primary and tertiary sector in a regional Australian health district. Participants included general practitioners, renal and general practice nurses, dietitians, nephrologists and social workers. APPROACH: The data were collected through semistructured interviews and analysed using a relativist ontological position and directed content analysis approach. Analysis of interviews was undertaken by three independent researchers and key themes were derived via consensus. FINDINGS AND CONCLUSIONS: A common goal to deliver person-centred individualised care was evident among health care professionals. However a deficit in shared understanding of the disease within and between disciplines was identified. The complex nature of chronic kidney disease requires up-skilling of health professionals to ensure patient education is targeted to individual health contexts and motivates self-management. Improved communication and comprehension might best be achieved across disciplines with an integrated approach to delivery of primary health care to individuals living with early-stage kidney disease.
Asunto(s)
Personal de Salud , Insuficiencia Renal Crónica , Australia , Atención a la Salud , Humanos , Investigación Cualitativa , Insuficiencia Renal Crónica/terapiaRESUMEN
The effect of fenitrothion exposure on birds was examined by measuring aerobic metabolism, blood hemoglobin content, plasma cholinesterases, and body weight for up to 21 d postdose. Peak metabolic rate was measured in a flight chamber in three-dose groups of house sparrows (Passer domesticus; 100 mg/kg = high, 60 mg/kg = medium, 30 mg/kg = low) and one-dose groups of zebra finches (Taeniopygia guttata; 3 mg/kg) and king quails (Coturnix chinensis; 26 mg/kg). Aerobic metabolism was measured during 1 h of exposure to subfreezing thermal conditions in low-dose house sparrows and king quails (26 mg/kg). Fenitrothion had no effect on metabolic rate during cold exposure or on blood hemoglobin at any time. By contrast, aerobic performance during exercise in sparrows was reduced by 58% (high), 18% (medium), and 20% (low), respectively, 2 d postdose. House sparrows (high) had the longest recovery period for peak metabolic rate (21 d) and plasma cholinesterase activity (14 d). House sparrows (high) and treated king quails had significantly lower myoglobin at 48 h postdose, whereas myoglobin was invariant in zebra finches and house sparrows (medium and low). Cholinesterase was maximally inhibited at 6 h postdose, and had recovered within 24 h, in house sparrows (low), king quails, and zebra finches. Exercise peak metabolic rate in zebra finches and king quails was reduced by 23% at 2 d and 3 d, respectively, despite these birds being asymptomatic in both behavior and plasma cholinesterase activities.
Asunto(s)
Aerobiosis , Frío , Fenitrotión/toxicidad , Plaguicidas/toxicidad , Condicionamiento Físico Animal , Gorriones/fisiología , Animales , Peso Corporal/efectos de los fármacos , Inhibidores de la Colinesterasa/toxicidad , Colinesterasas/metabolismo , Relación Dosis-Respuesta a Droga , Hemoglobinas/análisis , Gorriones/metabolismoRESUMEN
METHOD: A qualitative descriptive study collected data via telephone interviews with 20 purposively sampled GPs working in New South Wales. A thematic analysis guided by the study objectives was undertaken. RESULTS: The participating GPs had divergent management approaches to acne treatment, infrequently provided acne patients with written resources, and would value additional dermatological support. Furthermore, the GPs recognised psychosocial ramifications and patient distress as drivers for treatment and expedited referral to dermatologists. DISCUSSION: Avenues for improved patient outcomes include explicit attention to psychological morbidity beyond treatment of the acne itself and improved use of patient educational materials, along with consistent collaboration between GPs and dermatologists.
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Acné Vulgar/terapia , Médicos Generales/psicología , Pautas de la Práctica en Medicina/normas , Acné Vulgar/fisiopatología , Adulto , Actitud del Personal de Salud , Femenino , Medicina General/métodos , Humanos , Entrevistas como Asunto/métodos , Masculino , Persona de Mediana Edad , Nueva Gales del Sur , Pautas de la Práctica en Medicina/tendencias , Investigación CualitativaRESUMEN
We measured aerobic metabolism during cold exposure and exercise performance (run duration and oxygen consumption while running at 1 m s(-1)) in the fat-tailed dunnart Sminthopsis crassicaudata, a dasyurid marsupial, before and after ingestion of 30 mg kg(-1) of fenitrothion, an organophosphate (OP) pesticide. Running endurance of OP-exposed animals was less than half that of control animals over the first 3 days after dosing and 55% of control animal endurance on day 5 post-dose. Despite these declines, peak metabolic rate at this running speed (9.3 times basal metabolic rate; BMR) was unaffected by OP exposure. Peak metabolic rate (PMR) and cumulative oxygen consumption during a 1-h exposure to conditions equivalent to -20 degrees C did not differ between OP-treated and control dunnarts, with PMR averaging 11 times BMR. We conclude that fenitrothion-induced exercise fatigue is not due to limitations in oxygen or substrate delivery to muscle or in their uptake per se, but more likely relates to decreased ability to sustain high-frequency neuromuscular function. The persistence of locomotor impairment following OP exposure in otherwise asymptomatic animals emphasizes the importance of using performance-based measures when characterising sublethal effects of pesticide exposure in an ecological context.
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Aerobiosis/efectos de los fármacos , Inhibidores de la Colinesterasa/toxicidad , Fenitrotión/toxicidad , Insecticidas/toxicidad , Marsupiales/fisiología , Resistencia Física/efectos de los fármacos , Animales , Regulación de la Temperatura Corporal/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/enzimología , Inhibidores de la Colinesterasa/sangre , Colinesterasas/sangre , Interpretación Estadística de Datos , Fenitrotión/sangre , Insecticidas/sangre , Masculino , Metabolismo/efectos de los fármacos , Residuos de Plaguicidas/sangre , Carrera/fisiología , Termogénesis/efectos de los fármacosRESUMEN
Metastasis is the cause of death in the majority (â¼90%) of malignant cancers. The oral potassium-sparing diuretic amiloride and its 5-substituted derivative 5 -N, N-(hexamethylene)amiloride (HMA) reportedly show robust antitumor/metastasis effects in multiple in vitro and animal models. These effects are likely due, at least in part, to inhibition of the urokinase plasminogen activator (uPA), a key protease determinant of cell invasiveness and metastasis. This study reports the discovery of 6-substituted HMA analogs that show nanomolar potency against uPA, high selectivity over related trypsin-like serine proteases, and minimal inhibitory effects against epithelial sodium channels (ENaC), the diuretic and antikaliuretic target of amiloride. Reductions in lung metastases were demonstrated for two analogs in a late-stage experimental mouse metastasis model, and one analog completely inhibited formation of liver metastases in an orthotopic xenograft mouse model of pancreatic cancer. The results support further evaluation of 6-substituted HMA derivatives as uPA-targeting anticancer drugs.
Asunto(s)
Antineoplásicos/química , Antineoplásicos/farmacología , Diuresis/efectos de los fármacos , Descubrimiento de Drogas , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pancreáticas/tratamiento farmacológico , Activador de Plasminógeno de Tipo Uroquinasa/antagonistas & inhibidores , Amilorida/química , Animales , Movimiento Celular , Proliferación Celular , Cristalografía por Rayos X , Diuréticos/química , Diuréticos/farmacología , Femenino , Humanos , Neoplasias Pulmonares/secundario , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos NOD , Ratones Desnudos , Ratones SCID , Modelos Moleculares , Estructura Molecular , Neoplasias Pancreáticas/patología , Potasio/metabolismo , Conformación Proteica , Sodio/metabolismo , Relación Estructura-Actividad , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Huge aggregations of flightless locust nymphs pose a serious threat to agriculture when they reach plague proportions but provide a very visible and nutritious resource for native birds. Locust outbreaks occur in spring and summer months in semiarid regions of Australia. Fenitrothion, an organophosphate pesticide, is sprayed aerially to control locust plagues. To evaluate fenitrothion exposure in birds attending locust outbreaks, we measured total plasma cholinesterase (ChE), butrylcholinesterase (BChE), and acetylcholinesterase (AChE) activities in four avian species captured pre- and postfenitrothion application and ChE reactivation in birds caught postspray only. Eleven of 21 plasma samples from four species had ChE activity below the diagnostic threshold (two standard deviations below the mean ChE activity of prespray samples). Granivorous zebra finches (Taeniopygia guttata) and insectivorous white-winged trillers (Lalage sueurii) had significantly lower mean plasma total ChE, BChE, and AChE activity postspray, while other insectivores, white-browed (Artamus superciliosus) and masked woodswallows (Artamus personatus), did not. Cholinesterase was reactivated in 19 of the 73 plasma samples and in one of three brain samples. We conclude that native bird species are exposed to fenitrothion during locust control operations. This exposure could have detrimental impacts, as both locust outbreaks and avian reproductive events are stimulated by heavy summer rainfall, leading to co-occurrence of locust control and avian breeding activities.
Asunto(s)
Inhibidores de la Colinesterasa/toxicidad , Fenitrotión/toxicidad , Insecticidas/toxicidad , Passeriformes/metabolismo , Acetilcolinesterasa/sangre , Animales , Encéfalo/enzimología , Butirilcolinesterasa/sangre , Colinesterasas/análisis , Colinesterasas/sangre , Saltamontes , Control de Insectos , QueenslandRESUMEN
To lead positive change in the teaching practice of teams that service large numbers of diverse students from multiple degree programs provides many challenges. The primary aim of this study was to provide a clear framework on which to plan the process of change that can be utilized by academic departments sector wide. Barriers to change were reduced by adapting and utilizing Kotter's principals of change specifically by creating a sense of urgency and defining a clear goal designed to address the problem. Changing attitudes involved training staff in new teaching and learning approaches and strategies, and creating a collaborative, supportive team-based teaching environment within which the planned changes could be implemented and evaluated. As a result senior academics are now directly involved in delivering sections of the face-to-face teaching in the new environment. Through promoting positive change we enabled deeper student engagement with the theoretical concepts delivered in lectures as evidenced by favorable student evaluations, feedback, and improved final exam results. A collaborative team-based approach that recognizes the importance of distributed leadership combined with a clearly articulated change management process were central to enabling academics to design, try, and evaluate the new teaching and learning practices. Our study demonstrates that a concerted focus on "change management" enabled teaching team members to adopt a major shift in the teaching and learning approach that resulted in measurable improvements in student learning.
Asunto(s)
Educación Profesional/economía , Educación Profesional/métodos , Educación Profesional/tendencias , HumanosRESUMEN
The central bearded dragon (Pogona vitticeps) is a medium-sized lizard that is common in semiarid habitats in Australia and that potentially is at risk of fenitrothion exposure from use of the chemical in plague locust control. We examined the effects of single sublethal doses of this organophosphate (OP; low dose = 2.0 mg/kg; high dose = 20 mg/kg; control = vehicle alone) on lizard thermal preference, standard metabolic rate, and prey-capture ability. We also measured activities of plasma total cholinesterase (ChE) and acetylcholinesterase before and at 0, 2, 8, 24, 120, and 504 h after OP dosing. Predose plasma total ChE activity differed significantly between sexes and averaged 0.66 +/- 0.06 and 0.45 +/- 0.06 micromol/min/ml for males and females, respectively. Approximately 75% of total ChE activity was attributable to butyrylcholinesterase. Peak ChE inhibition reached 19% 2 h after OP ingestion in the low-dose group, and 68% 8 h after ingestion in high-dose animals. Neither OP doses significantly affected diurnal body temperature, standard metabolic rate, or feeding rate. Plasma total ChE levels remained substantially depressed up to 21 d after dosing in the high-dose group, making this species a useful long-term biomonitor of OP exposure in its habitat.