Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
Artículo en Inglés | MEDLINE | ID: mdl-36778763

RESUMEN

This national study explored the role of digital technologies in early childhood education and care settings and whether they could contribute to quality improvement as reported by educators and assessors of quality in Australia. In this paper, data from Stage 2 of the Quality Improvement Research Project were used, which comprised 60 Quality Improvement Plans from educators linked with 60 Assessment and Rating reports from the assessors who visited early childhood centres as part of the administration of the National Quality Standards by each of Australia's State and Territory jurisdictions. Bronfenbrenner's ecological systems theory ( Bronfenbrenner, U. (1995). Developmental ecology through space and time: A future perspective. In P. Moen, G. H. Elder, Jr., & K. Lüscher (Eds.), Examining lives in context: Perspectives on the ecology of human development (pp. 619-647). American Psychological Association. 10.1037/10176-018; Bronfenbrenner & Ceci, Bronfenbrenner and Ceci, Psychological Review 101:568-586, 1994) was adopted to facilitate a systemic and dynamic view on the use of digital technologies in these 60 ECEC settings. References (e.g. comments/ suggestions/ examples) made by the educators about the implementation of digital technologies were counted and thematically analysed. Results revealed the strong role new technologies (e.g. documentation and management platforms, tablets, apps, etc.) play in the majority of ECEC settings and especially in relation to three of the seven Quality Areas: Educational programme and practice (Quality Area 1); Collaborative partnerships with families and communities (Quality Area 6) and Governance and leadership (Quality Area 7). Future directions for research are suggested and implications for embracing a more holistic, integrated and broad view on the use of digital technologies are discussed.

2.
Aust Educ Res ; : 1-23, 2023 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-36620473

RESUMEN

This study assessed the impact of structural characteristics on quality rating and improvement systems (QRIS) outcomes in an Australian national study. Data from the Australian Children's Education and Care Quality Authority (ACECQA) repository of National Quality Standard (NQS) ratings were used to identify long day care services that had improved from Working Towards NQS to Meeting or Exceeding NQS or had no change over two assessments. QRIS outcomes were examined for state/territory jurisdiction, urban-rural location, community socio-economic status, type and size of provider organisation, centre size and stability of centre owner/provider using multinomial logistic regression analyses. Controlling for jurisdiction, results showed that improvement to Meeting NQS was more likely for not-for-profit versus for-profit providers and for large multi-site provider organisations versus small, stand-alone providers. Improvement to Exceeding NQS was also associated with not-for-profit and larger provider organisations, as well as larger versus smaller centres, and centres that had stable ownership.

3.
BMJ Open ; 12(12): e065568, 2022 12 29.
Artículo en Inglés | MEDLINE | ID: mdl-36581427

RESUMEN

OBJECTIVES: To determine the negative predictive value (NPV) of the FebriDx point-of-care host response device in patients presenting with symptoms suggestive of COVID-19 infection in a mostly immunised Australian emergency department (ED) population during the late 2021 phase of the COVID-19 pandemic. DESIGN: Observational diagnostic accuracy study comparing FebriDx point-of-care test to SARS-CoV-2 PCR. SETTING: An ED in Melbourne, Australia, with 63 000 annual presentations in 2021. PARTICIPANTS: Patients aged 16 and over who met the Victorian Department of Health case definition for suspected COVID-19 infection PCR testing. Patients meeting any of the following criteria were excluded: <16 years of age; acute respiratory symptom(s) with onset>14 days prior to testing; current immunosuppressive or interferon therapy; live immunisation within the last 30 days; fever lasting>7 days; antibiotic or antiviral use in the preceding 14 days; experience of major trauma, major surgical intervention or severe burns within the last 30 days. PRIMARY AND SECONDARY OUTCOME MEASURES: COVID-19 PCR results (detected, not detected) and FebriDx results (bacterial positive, viral negative, viral positive). RESULTS: 94 participants were enrolled (female: 46; male: 48), 34% of participants (tested positive for COVID-19 according to PCR results, with a background incidence among all adult ED attenders of 2.5%. The sensitivity of FebriDx for detection of COVID-19 was 56% (95% CI 40% to 100%) and specificity was 92% (95% CI 84% to 100%). For the population tested, this resulted in an NPV of 80% (95% CI 71% to 100%) and a positive predictive value of 78% (95% CI 60% to 100%). CONCLUSIONS: In the context of a population with low COVID-19 infection rates, an evolved variant of COVID-19 and a very high community COVID-19 vaccination rate, FebriDx demonstrated reduced sensitivity and NPV relative to results from earlier international tests. These contextual factors should be considered during any attempt to generalise the current results. TRIAL REGISTRATION NUMBER: ACTRN12620001029987 (Australian Clinical Trials).


Asunto(s)
COVID-19 , Adulto , Humanos , Masculino , Femenino , Adolescente , COVID-19/diagnóstico , COVID-19/epidemiología , Valor Predictivo de las Pruebas , SARS-CoV-2 , Pandemias , Vacunas contra la COVID-19 , Australia/epidemiología , Pruebas en el Punto de Atención , Servicio de Urgencia en Hospital
4.
Ann Bot ; 129(6): 669-678, 2022 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-35247265

RESUMEN

BACKGROUND AND AIMS: Many terrestrial orchids have an obligate dependence on their mycorrhizal associations for nutrient acquisition, particularly during germination and early seedling growth. Though important in plant growth and development, phosphorus (P) nutrition studies in mixotrophic orchids have been limited to only a few orchid species and their fungal symbionts. For the first time, we demonstrate the role of a range of fungi in the acquisition and transport of inorganic P to four phylogenetically distinct green-leaved terrestrial orchid species (Diuris magnifica, Disa bracteata, Pterostylis sanguinea and Microtis media subsp. media) that naturally grow in P-impoverished soils. METHODS: Mycorrhizal P uptake and transfer to orchids was determined and visualized using agar microcosms with a diffusion barrier between P source (33P orthophosphate) and orchid seedlings, allowing extramatrical hyphae to reach the source. KEY RESULTS: Extramatrical hyphae of the studied orchid species were effective in capturing and transporting inorganic P into the plant. Following 7 d of exposure, between 0.5 % (D. bracteata) and 47 % (D. magnifica) of the P supplied was transported to the plants (at rates between 0.001 and 0.097 fmol h-1). This experimental approach was capable of distinguishing species based on their P-foraging efficiency, and highlighted the role that fungi play in P nutrition during early seedling development. CONCLUSIONS: Our study shows that orchids occurring naturally on P-impoverished soils can obtain significant amounts of inorganic P from their mycorrhizal partners, and significantly more uptake of P supplied than previously shown in other green-leaved orchids. These results provide support for differences in mycorrhiza-mediated P acquisition between orchid species and fungal symbionts in green-leaved orchids at the seedling stage. The plant-fungus combinations of this study also provide evidence for plant-mediated niche differentiation occurring, with ecological implications in P-limited systems.


Asunto(s)
Basidiomycota , Micorrizas , Orchidaceae , Orchidaceae/microbiología , Fósforo , Plantones/microbiología , Suelo , Simbiosis
5.
Ann Bot ; 126(5): 943-955, 2020 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-32574356

RESUMEN

BACKGROUND AND AIMS: In orchid conservation, quantifying the specificity of mycorrhizal associations, and establishing which orchid species use the same fungal taxa, is important for sourcing suitable fungi for symbiotic propagation and selecting sites for conservation translocation. For Caladenia subgenus Calonema (Orchidaceae), which contains 58 threatened species, we ask the following questions. (1) How many taxa of Serendipita mycorrhizal fungi do threatened species of Caladenia associate with? (2) Do threatened Caladenia share orchid mycorrhizal fungi with common Caladenia? (3) How geographically widespread are mycorrhizal fungi associated with Caladenia? METHODS: Fungi were isolated from 127 Caladenia species followed by DNA sequencing of the internal transcibed spacer (ITS) sequence locus. We used a 4.1-6 % sequence divergence cut-off range to delimit Serendipita operational taxonomic units (OTUs). We conducted trials testing the ability of fungal isolates to support germination and plant growth. A total of 597 Serendipita isolates from Caladenia, collected from across the Australian continent, were used to estimate the geographic range of OTUs. KEY RESULTS: Across the genus, Caladenia associated with ten OTUs of Serendipita (Serendipitaceae) mycorrhizal fungi. Specificity was high, with 19 of the 23 threatened Caladenia species sampled in detail associating solely with OTU A, which supported plants from germination to adulthood. The majority of populations of Caladenia associated with one OTU per site. Fungal sharing was extensive, with 62 of the 79 Caladenia sampled in subgenus Calonema associating with OTU A. Most Serendipita OTUs were geographically widespread. CONCLUSIONS: Mycorrhizal fungi can be isolated from related common species to propagate threatened Caladenia. Because of high specificity of most Caladenia species, only small numbers of OTUs typically need to be considered for conservation translocation. When selecting translocation sites, the geographic range of the fungi is not a limiting factor, and using related Caladenia species to infer the presence of suitable fungal OTUs may be feasible.


Asunto(s)
Micorrizas , Orchidaceae , Animales , Australia , ADN de Hongos/genética , Micorrizas/genética , Filogenia , Simbiosis
6.
Ann Bot ; 116(3): 413-21, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26105186

RESUMEN

BACKGROUND AND AIMS: Although mycorrhizal associations are predominantly generalist, specialized mycorrhizal interactions have repeatedly evolved in Orchidaceae, suggesting a potential role in limiting the geographical range of orchid species. In particular, the Australian orchid flora is characterized by high mycorrhizal specialization and short-range endemism. This study investigates the mycorrhizae used by Pheladenia deformis, one of the few orchid species to occur across the Australian continent. Specifically, it examines whether P. deformis is widely distributed through using multiple fungi or a single widespread fungus, and if the fungi used by Australian orchids are widespread at the continental scale. METHODS: Mycorrhizal fungi were isolated from P. deformis populations in eastern and western Australia. Germination trials using seed from western Australian populations were conducted to test if these fungi supported germination, regardless of the region in which they occurred. A phylogenetic analysis was undertaken using isolates from P. deformis and other Australian orchids that use the genus Sebacina to test for the occurrence of operational taxonomic units (OTUs) in eastern and western Australia. KEY RESULTS: With the exception of one isolate, all fungi used by P. deformis belonged to a single fungal OTU of Sebacina. Fungal isolates from eastern and western Australia supported germination of P. deformis. A phylogenetic analysis of Australian Sebacina revealed that all of the OTUs that had been well sampled occurred on both sides of the continent. CONCLUSIONS: The use of a widespread fungal OTU in P. deformis enables a broad distribution despite high mycorrhizal specificity. The Sebacina OTUs that are used by a range of Australian orchids occur on both sides of the continent, demonstrating that the short-range endemism prevalent in the orchids is not driven by fungal species with narrow distributions. Alternatively, a combination of specific edaphic requirements and a high incidence of pollination by sexual deception may explain biogeographic patterns in southern Australian orchids.


Asunto(s)
Micorrizas/fisiología , Orchidaceae/microbiología , Orchidaceae/fisiología , Dispersión de las Plantas , Proteínas Fúngicas/genética , Germinación , Micorrizas/genética , Orchidaceae/crecimiento & desarrollo , Filogenia , Análisis de Secuencia de ADN , Especificidad de la Especie
8.
Sex Health ; 7(1): 60-5, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20152098

RESUMEN

BACKGROUND: We hypothesise that text-messaging and financial incentives would increase tertiary student participation in chlamydia screening. METHODS: A cross-sectional study was conducted over two phases on eight tertiary campuses during 2007. During Phase 1 (6 months) study activities were advertised through student organisations and media. Education and screening were offered during a range of student activities. During Phase 2 (4 days) education and screening were offered via text messages. Non-financial incentives were offered during Phase 1 and a $10 cash incentive was offered during Phase 2. Rates of specimens provided by students and the direct costs incurred during each phase were compared. RESULTS: 2786 students attended the 31 activities conducted in Phase 1. Of these, 627 students (22.5%) provided urine specimens for chlamydia testing. During Phase 2, the dissemination of 866 text messages resulted in urine specimens from 392 students (45.3%). Costs per test were AUD $175.11 in Phase 1 and AUD $27.13 in Phase 2. CONCLUSIONS: Compared with more labour intensive (and therefore more expensive) screening activities conducted over a 6-month period, offering a small financial incentive to tertiary students through text messaging over a 4-day period significantly increased participation in on-campus chlamydia screening. This model could readily be applied to other populations to increase participation in chlamydia screening.


Asunto(s)
Infecciones por Chlamydia/diagnóstico , Infecciones por Chlamydia/economía , Tamizaje Masivo/economía , Aceptación de la Atención de Salud/estadística & datos numéricos , Participación del Paciente/economía , Estudiantes/estadística & datos numéricos , Adulto , Infecciones por Chlamydia/epidemiología , Chlamydia trachomatis/aislamiento & purificación , Costos y Análisis de Costo , Estudios Transversales , Femenino , Humanos , Masculino , Motivación , Nueva Gales del Sur/epidemiología , Proyectos Piloto , Adulto Joven
9.
BMC Res Notes ; 2: 38, 2009 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-19284535

RESUMEN

BACKGROUND: Achromobacter sp. AO22 (formerly Alcaligenes sp. AO22), a bacterial strain isolated from a lead-contaminated industrial site in Australia, was previously found to be resistant to moderate to high levels of mercury, copper and other heavy metals. However, the nature and location of the genetic basis for mercuric ion resistance in this strain, had not been previously identified. FINDINGS: Achromobacter sp. AO22 contains a functional mer operon with all four essential genes (merRTPA) and shows >99% DNA sequence identity to that of Tn501. The mer operon was present on a transposon, designated TnAO22, captured by introducing a broad-host-range IncP plasmid into Achromobacter sp. AO22 and subsequently transferring it to E. coli recipients. The transposition frequency of TnAO22 was 10-2 to 10-3 per target plasmid transferred. Analysis of TnAO22 sequence revealed it belonged to the Tn21 subgroup of the Tn3 superfamily of transposons, with the transposition module having >99% identity with Tn5051 of a Pseudomonas putida strain isolated from a water sample in New York. CONCLUSION: TnAO22 is thus a new variant of Tn5051 of the Tn3 superfamily and the transposon and its associated mercury resistance system are among the few such systems reported in a soil bacterium. Achromobacter sp. AO22 can thus be exploited for applications such as in situ mercury bioremediation of contaminated sites, or the mobile unit and mer operon could be mobilized to other bacteria for similar purposes.

10.
J Am Soc Nephrol ; 18(8): 2320-9, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17625119

RESUMEN

Angiopoietin-2 (Ang-2) modulates embryonic vascular differentiation primarily by inhibiting the antiapoptotic effects of Ang-1 on endothelia that express the Tie-2 receptor. Ang-2 is transiently expressed by developing glomeruli but is downregulated with normal maturation. Glomerular Ang-2 expression is, however, markedly upregulated in animal models of diabetic nephropathy and glomerulonephritis, both leading causes of human chronic renal disease, affecting 10% of the world population. It was hypothesized that Ang-2 might have significant roles in the pathobiology of glomerular disease. Mice with inducible podocyte-specific Ang-2 overexpression were generated. When the transgene was induced in adults for up to 10 wk, mice had significant increases in both albuminuria and glomerular endothelial apoptosis, with significant decreases of both vascular endothelial growth factor-A and nephrin proteins, critical for maintenance of glomerular endothelia and filtration barrier functional integrity, respectively. There was, however, no significant change of systemic BP, creatinine clearance, or markers of renal fibrosis, and podocytes appeared structurally intact. In kidneys of young animals in which Ang-2 had been upregulated during organogenesis, increased apoptosis occurred in just-formed glomeruli. In vitro, short-term exposure of isolated wild-type murine glomeruli to exogenous Ang-2 led to decreased levels of vascular endothelial growth factor-A protein. These novel results provide insight into molecular mechanisms underlying proteinuric disorders, highlight potentially complex interactions between subsets of glomerular cells, and emphasize how a vascular growth factor that has critical roles in normal development may be harmful when re-expressed in the context of adult disease.


Asunto(s)
Angiopoyetina 2/genética , Apoptosis/fisiología , Podocitos/fisiología , Proteinuria/patología , Proteinuria/fisiopatología , Angiopoyetina 2/metabolismo , Animales , Regulación hacia Abajo , Células Endoteliales/patología , Células Endoteliales/fisiología , Células Endoteliales/ultraestructura , Femenino , Regulación de la Expresión Génica , Glomérulos Renales/embriología , Glomérulos Renales/crecimiento & desarrollo , Glomérulos Renales/patología , Operón Lac , Masculino , Ratones , Ratones Endogámicos CBA , Ratones Transgénicos , Microscopía Electrónica , Podocitos/ultraestructura , Embarazo , Transgenes/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo
11.
J Hypertens ; 23(11): 2071-82, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16208151

RESUMEN

OBJECTIVE: To investigate the effects of the combined angiotensin-converting enzyme (ACE)/neutral endopeptidase (NEP) inhibitor omapatrilat on atherosclerosis and renal injury in a model of diabetes-associated accelerated atherosclerosis and renal injury. DESIGN: The study was performed using diabetic apolipoprotein E-knockout (apo E-KO) mice, a model combining hyperlipidemia and hyperglycemia, which leads to accelerated atherosclerosis and renal injury. METHODS: Diabetes was induced by the injection of streptozotocin in 6-week old apo E-KO mice. Diabetic animals received no treatment (n = 12) or treatment with the ACE/NEP inhibitor omapatrilat (30 mg/kg per day, via gavage, n = 12) or quinapril (10 mg/kg per day, in drinking water, n = 12) for 20 weeks. Non-diabetic apo E-KO mice (n = 12) served as controls. RESULTS: Omapatrilat reduced atherosclerosis and protected the mice from renal structural injury and albuminuria. The protective effects were associated with tissue inhibition of aortic and renal ACE and NEP as well as a significant reduction in blood pressure. Omapatrilat had similar anti-atherosclerotic effects compared with the ACE inhibitor quinapril in association with an almost complete inhibition of aortic ACE activity by both drugs. Omapatrilat conferred superior renoprotection in the diabetic apo E-KO mouse compared with quinapril in the context of greater renal ACE inhibition by omapatrilat than seen with quinapril, additional renal NEP inhibition and a modestly enhanced antihypertensive response. CONCLUSIONS: These studies demonstrate the anti-atherosclerotic and renoprotective effects of omapatrilat in diabetic apo E-KO mice, a model of accelerated atherosclerosis and renal injury. These effects were observed in association with the local inhibition of ACE and NEP at the tissue level in the aorta and kidney. These results suggest that the anti-atherosclerotic effect conferred by omapatrilat treatment in the diabetic apo E-KO mouse is predominantly mediated by its capacity to inhibit local vascular ACE. By contrast, in the kidney, local renal ACE and NEP inhibition and the superior antihypertensive effect of omapatrilat all contribute to the renoprotective effect conferred by omapatrilat treatment in the diabetic apo E-KO mouse.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Apolipoproteínas E/genética , Aterosclerosis/prevención & control , Riñón/efectos de los fármacos , Neprilisina/antagonistas & inhibidores , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Animales , Antihipertensivos/farmacología , Aorta/efectos de los fármacos , Aorta/metabolismo , Aorta/patología , Apolipoproteínas E/metabolismo , Aterosclerosis/metabolismo , Aterosclerosis/patología , Biomarcadores/sangre , Glucemia/metabolismo , Presión Sanguínea/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Diabetes Mellitus/metabolismo , Diabetes Mellitus/patología , Diabetes Mellitus/prevención & control , Hemoglobina Glucada/metabolismo , Riñón/metabolismo , Riñón/patología , Enfermedades Renales/metabolismo , Enfermedades Renales/patología , Enfermedades Renales/prevención & control , Masculino , Ratones , Ratones Noqueados , Neprilisina/metabolismo , Tamaño de los Órganos/efectos de los fármacos , Peptidil-Dipeptidasa A/metabolismo , Inhibidores de Proteasas/farmacología , Inhibidores de Proteasas/uso terapéutico , Piridinas/farmacología , Quinapril , Tetrahidroisoquinolinas/farmacología , Tiazepinas/farmacología
12.
Am J Hypertens ; 18(6): 844-50, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15925746

RESUMEN

BACKGROUND: The aim of the present study was to compare glomerular permeability alterations associated with experimental hypertension models known to have different effects on the circulating renin-angiotensin system (RAS). METHODS: Five groups, 10 animals each, were studied. One group served as a nonhypertensive control. The other four groups of hypertensive animals were composed of spontaneously hypertensive rats, deoxycorticosterone acetate hypertensive rats, Goldblatt two-kidney, one-clip rats, and a group of Wistar rats infused with angiotensin II (200 ng/kg/min). Tail-cuff sphygmomanometric systolic blood pressure (BP), albumin permeability determined in isolated glomeruli exposed to oncotic gradients (P(alb)), glomerular filtration rate (GFR, iopamidol method), plasma renin activity (PRA), and albuminuria were evaluated. RESULTS: Alterations in P(alb) and albumin excretion rate were more evident in the experimental models with an activation of the RAS despite similar levels of systolic BP and GFR. A positive correlation was found between P(alb) and albuminuria (r = 0.51; P < .001) and between systolic BP and albuminuria (r = 0.37; P < .01). No relation was found between systolic BP and P(alb). CONCLUSIONS: The present study indicates that the activation of the RAS plays a significant role in the development of glomerular albumin permeability defects in hypertensive models and may contribute to the mechanisms that lead to target organ damage in hypertension.


Asunto(s)
Hipertensión/metabolismo , Glomérulos Renales/metabolismo , Sistema Renina-Angiotensina/fisiología , Albúminas/metabolismo , Angiotensina II/farmacocinética , Animales , Presión Sanguínea/efectos de los fármacos , Permeabilidad de la Membrana Celular/fisiología , Desoxicorticosterona/análogos & derivados , Desoxicorticosterona/toxicidad , Modelos Animales de Enfermedad , Estudios de Seguimiento , Tasa de Filtración Glomerular/efectos de los fármacos , Hipertensión/inducido químicamente , Masculino , Radioinmunoensayo , Ratas , Ratas Endogámicas Dahl , Ratas Endogámicas SHR , Ratas Wistar , Renina/sangre , Vasoconstrictores/farmacocinética
13.
J Health Soc Policy ; 17(1): 39-53, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14620735

RESUMEN

This paper examines an attempt by the State of Florida to devise a mechanism for determining the level of drug use among TANF recipients and to determine the extent to which such use affects employment, earnings and use of government services by TANF beneficiaries. Data from tests administered by substance abuse testing providers were combined with information from Medicaid, Food Stamp, cash assistance and Unemployment Insurance files to examine differences between the two groups. The findings suggest that the procedures employed by the State of Florida did not produce reliable estimates of the level of drug use among TANF beneficiaries. The data did show very small differences in employment, earnings, and use of government services between individuals who tested positively and those who tested negatively for substance abuse. In addition, evidence is presented that suggests that there is very little difference in employment, earnings and use of government services between users of different kinds of drugs.


Asunto(s)
Asistencia Pública/estadística & datos numéricos , Bienestar Social/estadística & datos numéricos , Trastornos Relacionados con Sustancias/epidemiología , Empleo , Florida/epidemiología , Humanos , Renta , Proyectos Piloto , Bienestar Social/economía , Bienestar Social/legislación & jurisprudencia , Detección de Abuso de Sustancias , Trastornos Relacionados con Sustancias/diagnóstico
14.
Clin Sci (Lond) ; 104(4): 341-7, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12653675

RESUMEN

The aim of the present study was to compare the antihypertrophic effects of blockade of the renin-angiotensin system (RAS), vasopeptidase inhibition and calcium channel antagonism on cardiac and vascular hypertrophy in diabetic spontaneously hypertensive rats (SHR). SHR with streptozotocin-induced diabetes were treated with one of the following therapies for 32 weeks: the angiotensin-converting enzyme (ACE) inhibitor captopril (100 mg/kg); the angiotensin AT(1) receptor antagonist valsartan (30 mg/kg); a combination of captopril with valsartan; the vasopeptidase inhibitor mixanpril (100 mg/kg); or the calcium channel antagonist amlodipine (6 mg/kg). Systolic blood pressure and cardiac and mesenteric artery hypertrophy were assessed. Mean systolic blood pressure in diabetic SHR (200+/-5 mmHg) was reduced by captopril (162+/-5 mmHg), valsartan (173+/-5 mmHg), mixanpril (176+/-2 mmHg) and amlodipine (159+/-4 mmHg), and was further reduced by the combination of captopril with valsartan (131+/-5 mmHg). Captopril, valsartan and mixanpril reduced heart and left ventricle weights by approx. 10%. The combination of captopril and valsartan further reduced heart weight (-24%) and left ventricular weight (-29%). Amlodipine did not affect cardiac hypertrophy. Only mixanpril and the combination of captopril and valsartan significantly reduced mesenteric weight. The mesenteric wall/lumen ratio was reduced by all drugs, and to a greater extent by the combination of captopril and valsartan. We conclude that optimizing the blockade of vasoconstrictive pathways such as the RAS, particularly with the combination of ACE inhibition and AT(1) receptor antagonism, is associated with antitrophic effects in the context of diabetes and hypertension. In contrast, calcium channel blockade, despite similar effects on blood pressure, confers less antitrophic effects in the diabetic heart and blood vessels.


Asunto(s)
Alanina/análogos & derivados , Cardiomegalia/prevención & control , Hipertensión/complicaciones , Sistema Renina-Angiotensina/efectos de los fármacos , Valina/análogos & derivados , Alanina/uso terapéutico , Amiodarona/uso terapéutico , Antagonistas de Receptores de Angiotensina , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Animales , Bloqueadores de los Canales de Calcio/uso terapéutico , Captopril/uso terapéutico , Cardiomegalia/sangre , Cardiomegalia/etiología , Diabetes Mellitus Experimental , Quimioterapia Combinada , Inhibidores Enzimáticos/uso terapéutico , Hipertensión/sangre , Hipertensión/tratamiento farmacológico , Hipertrofia , Masculino , Arterias Mesentéricas/patología , Neprilisina/antagonistas & inhibidores , Ratas , Ratas Endogámicas SHR , Receptor de Angiotensina Tipo 1 , Renina/sangre , Tetrazoles/uso terapéutico , Valina/uso terapéutico , Valsartán
15.
J Hypertens ; 21(1): 209-16, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12544453

RESUMEN

OBJECTIVE AND DESIGN: To explore the effects of various antihypertensive regimes which achieve similar blood pressure control using a range of agents including the angiotensin II type 1 receptor antagonist, valsartan, as monotherapy or in combination with two subclasses of calcium channel blockers (CCBs) (the dihydropyridine, amlodipine and the phenylalkylamine, verapamil) on the progression of renal disease and the expression of the podocyte slit pore protein, nephrin in an accelerated model of diabetic nephropathy. RESULTS: Valsartan treatment reduced systolic blood pressure as assessed by radiotelemetry (135 +/- 3 versus diabetic 153 +/- 6 mmHg) as well as retarding the increase in albumin excretion rate by approximately 50%. Combination therapy of valsartan with either amlodipine or verapamil was equally effective in reducing blood pressure to valsartan monotherapy (valsartan + amlodipine 129 +/- 4 valsartan + verapamil 133 +/- 6 mmHg;) but was not as effective at reducing albuminuria. A reduction in glomerulosclerosis was observed with valsartan monotherapy with less reduction in injury with the valsartan + amlodipine combination, despite a similar reduction in blood pressure. The decrease in nephrin, in diabetic rats was attenuated by valsartan monotherapy, but not by other treatments. CONCLUSIONS: The results of this study demonstrate that despite a similar reduction in blood pressure, the addition of the CCB amlodipine to the AII antagonist failed to provide similar renoprotection to that observed with an equihypotensive regimen of valsartan as monotherapy. Furthermore, the depletion in glomerular nephrin expression in diabetic animals was only abrogated by valsartan treatment, the therapy which was most effective at retarding the development of albuminuria in this model.


Asunto(s)
Albuminuria/orina , Antagonistas de Receptores de Angiotensina , Antihipertensivos/farmacología , Bloqueadores de los Canales de Calcio/farmacología , Nefropatías Diabéticas/orina , Hipertensión/orina , Proteínas/metabolismo , Valina/análogos & derivados , Albuminuria/tratamiento farmacológico , Albuminuria/etiología , Amlodipino/farmacología , Animales , Presión Sanguínea/efectos de los fármacos , Diabetes Mellitus Experimental/complicaciones , Nefropatías Diabéticas/complicaciones , Nefropatías Diabéticas/patología , Nefropatías Diabéticas/fisiopatología , Modelos Animales de Enfermedad , Quimioterapia Combinada , Hipertensión/complicaciones , Hipertensión/tratamiento farmacológico , Hipertensión/patología , Hipertensión/fisiopatología , Glomérulos Renales/patología , Masculino , Proteínas de la Membrana , Ratas , Ratas Endogámicas SHR , Receptor de Angiotensina Tipo 1 , Esclerosis , Sístole , Tetrazoles/farmacología , Valina/farmacología , Valsartán , Verapamilo/farmacología
16.
Diabetes ; 51(11): 3283-9, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12401720

RESUMEN

The severe diabetic nephropathy that develops in the hypertensive transgenic (mRen-2)27 rat with streptozotocin (STZ) diabetes has previously been considered angiotensin II-dependent. Because metabolic pathways are also activated in the diabetic kidney, the present study aimed to determine whether renoprotection could be afforded with inhibitors of advanced glycation end products (AGEs), ALT-946, and aminoguanidine (AG). At 6 weeks of age, nondiabetic control and STZ diabetic Ren-2 rats were randomized to receive vehicle, ALT-946 (1 g/l), or AG (1 g/l) and were studied for 12 weeks. Systolic blood pressure was unchanged with diabetes, ALT-946, or AG. Both kidney weight and glomerular filtration rate were increased with diabetes and unchanged with ALT-946 or AG. ALT-946 and AG equally ameliorated glomerulosclerosis and medullary pathology; however, ALT-946 did reduce cortical tubular degeneration to a greater extent than AG. Albumin excretion rate, which was elevated with diabetes, was reduced with ALT-946 but not AG. AGE immunolabeling was increased in glomeruli and reduced with ALT-946 and AG. These findings indicate that even in the context of renal injury presumed to be primarily blood pressure- and/or angiotensin II-dependent, approaches that interfere with metabolic pathways such as inhibitors of AGE formation can confer renal protection in experimental diabetes.


Asunto(s)
Amidas/uso terapéutico , Diabetes Mellitus Experimental/complicaciones , Nefropatías Diabéticas/tratamiento farmacológico , Productos Finales de Glicación Avanzada/metabolismo , Guanidinas/uso terapéutico , Hidrazinas/uso terapéutico , Animales , Animales Modificados Genéticamente , Presión Sanguínea , Peso Corporal/efectos de los fármacos , Diabetes Mellitus Experimental/fisiopatología , Nefropatías Diabéticas/patología , Nefropatías Diabéticas/fisiopatología , Inhibidores Enzimáticos/uso terapéutico , Tasa de Filtración Glomerular , Inmunohistoquímica , Corteza Renal/efectos de los fármacos , Corteza Renal/patología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Tamaño de los Órganos/efectos de los fármacos , Ratas , Ratas Mutantes
17.
Comp Biochem Physiol A Mol Integr Physiol ; 132(4): 893-903, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12095869

RESUMEN

This study investigated the mRNA expression of the atrial natriuretic peptide (ANP) system (peptide and receptors) during water deprivation in the spinifex hopping mouse, Notomys alexis, a native of central and western Australia that is well adapted to survive in arid environments. Initially, ANP, NPR-A and NPR-C cDNAs (partial for receptors) were cloned and sequenced, and were shown to have high homology with those of rat and mouse. Using a semi-quantitative multiplex PCR technique, the expression of cardiac ANP mRNA and renal ANP, NPR-A, and NPR-C mRNA was determined in 7- and 14-day water-deprived hopping mice, in parallel with control mice (access to water). The levels of ANP mRNA expression in the heart remained unchanged, but in the kidney ANP mRNA levels were increased in the 7-day water-deprived mice, and were significantly decreased in the 14-day water-deprived mice. NPR-A mRNA levels were significantly higher in 7-day water-deprived mice while no change for NPR-A mRNA expression was observed in 14-day water-deprived mice. No variation in NPR-C mRNA levels was observed. This study shows that water deprivation differentially affects the expression of the ANP system, and that renal ANP expression is more important than cardiac ANP in the physiological adjustment to water deprivation.


Asunto(s)
Factor Natriurético Atrial/genética , Guanilato Ciclasa/genética , Muridae/genética , Receptores del Factor Natriurético Atrial/genética , Privación de Agua/fisiología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , ADN Complementario/genética , Expresión Génica , Corazón/fisiología , Riñón/fisiología , Ratones , Datos de Secuencia Molecular , Muridae/fisiología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Homología de Secuencia de Aminoácido
18.
Clin Infect Dis ; 34(12): 1593-9, 2002 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-12032894

RESUMEN

We investigated an outbreak of leptospirosis among athletes and community residents after a triathlon was held in Springfield, Illinois. A telephone survey was conducted to collect clinical information and data on possible risk factors, community surveillance was established, and animal specimens and lake water samples were collected to determine the source of the leptospiral contamination. A total of 834 of 876 triathletes were contacted; 98 (12%) reported being ill. Serum samples obtained from 474 athletes were tested; 52 of these samples (11%) tested positive for leptospirosis. Fourteen (6%) of 248 symptomatic community residents tested positive for leptospirosis. Heavy rains that preceded the triathlon are likely to have increased leptospiral contamination of Lake Springfield. Among athletes, ingestion of 1 or more swallows of lake water was a predominant risk factor for illness. This is the largest outbreak of leptospirosis that has been reported in the United States. Health care providers and occupational and recreational users of bodies of freshwater in the United States should be aware of the risk of contracting leptospirosis, particularly after heavy rains.


Asunto(s)
Infecciones Comunitarias Adquiridas/epidemiología , Brotes de Enfermedades , Leptospira/aislamiento & purificación , Leptospirosis/epidemiología , Adulto , Infecciones Comunitarias Adquiridas/microbiología , Femenino , Humanos , Illinois/epidemiología , Leptospirosis/microbiología , Masculino , Análisis Multivariante , Deportes , Microbiología del Agua
19.
J Hypertens ; 20(4): 707-14, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11910307

RESUMEN

OBJECTIVE: The effects of combined inhibition of neutral endopeptidase (NEP) with either angiotensin-converting enzyme (ACE), or endothelin-converting enzyme (ECE) on blood pressure, urinary albumin excretion and heart weight were explored in experimental diabetes. DESIGN: Streptozotocin-induced diabetic Sprague-Dawley rats were treated with vehicle, the NEP/ACE inhibitor S 21402, the NEP/ECE inhibitor CGS 26303, the NEP inhibitor SCH 42495, the ACE inhibitor captopril or the endothelin receptor antagonist bosentan for 4 weeks. METHODS: Blood pressure was measured by tail-cuff method and radiotelemetry. Albuminuria, plasma renin activity and plasma atrial natriuretic peptide (ANP) were determined by radioimmunoassay. NEP binding was assessed by in vitro quantitative autoradiography. Metabolic and biochemistry parameters including food intake, 24-h urine volume, plasma glucose, glycated hemoglobin, glomerular filtration rate (GFR) and urinary sodium excretion were also determined. RESULTS: Mean blood pressure over the 4-week study period after commencement of treatment was reduced to a similar extent by a range of treatments including the ACE inhibitor, NEP/ACE inhibitor, endothelin receptor antagonist, NEP/ECE inhibitor, but not the NEP inhibitor, compared with vehicle-treated diabetic rats. Heart to body weight ratio in diabetic rats was only reduced by the NEP/ACE and the NEP/ECE inhibitor. Increased albuminuria in diabetic rats (1.1 times/divided by 1.2 mg/day) was reduced by the NEP/ACE (0.6 times/divided by 1.2 mg/day) and the NEP/ECE inhibitors (0.4 times/divided by 1.2 mg/day). Renal NEP was reduced by the NEP/ACE inhibitor (35 +/- 4%) or NEP/ECE inhibitor (38 +/- 4%) as well as by the pure NEP inhibitor (27 +/- 4%) compared with the untreated diabetic group. Other abnormal metabolic and biochemical parameters in diabetic rats were not influenced by any drug treatment. CONCLUSIONS: Combined inhibition of NEP/ACE or NEP/ECE confers beneficial effects on blood pressure, albuminuria and heart to body weight ratio in experimental diabetes.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/enzimología , Neprilisina/antagonistas & inhibidores , Inhibidores de Proteasas/farmacología , Albuminuria/tratamiento farmacológico , Inhibidores de la Enzima Convertidora de Angiotensina/administración & dosificación , Animales , Factor Natriurético Atrial/sangre , Presión Sanguínea/efectos de los fármacos , Bosentán , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Experimental/fisiopatología , Interacciones Farmacológicas , Antagonistas de los Receptores de Endotelina , Enzimas Convertidoras de Endotelina , Corazón/efectos de los fármacos , Riñón/efectos de los fármacos , Riñón/fisiopatología , Masculino , Metaloendopeptidasas , Miocardio/patología , Tamaño de los Órganos/efectos de los fármacos , Organofosfonatos/administración & dosificación , Organofosfonatos/sangre , Organofosfonatos/farmacología , Inhibidores de Proteasas/administración & dosificación , Inhibidores de Proteasas/sangre , Ratas , Ratas Sprague-Dawley , Renina/sangre , Sulfonamidas/administración & dosificación , Sulfonamidas/farmacología , Tetrazoles/administración & dosificación , Tetrazoles/sangre , Tetrazoles/farmacología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...