Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
1.
Proc Natl Acad Sci U S A ; 114(35): 9397-9402, 2017 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-28808019

RESUMO

In host-pathogen arms races, increases in host resistance prompt counteradaptation by pathogens, but the nature of that counteradaptation is seldom directly observed outside of laboratory models. The best-documented field example is the coevolution of myxoma virus (MYXV) in European rabbits. To understand how MYXV in Australia has continued to evolve in wild rabbits under intense selection for genetic resistance to myxomatosis, we compared the phenotypes of the progenitor MYXV and viral isolates from the 1950s and the 1990s in laboratory rabbits with no resistance. Strikingly, and unlike their 1950s counterparts, most virus isolates from the 1990s induced a highly lethal immune collapse syndrome similar to septic shock. Thus, the next step in this canonical case of coevolution after a species jump has been further escalation by the virus in the face of widespread host resistance.


Assuntos
Myxoma virus/genética , Infecções por Poxviridae/veterinária , Coelhos/virologia , Infecções Tumorais por Vírus/veterinária , Animais , Austrália/epidemiologia , Evolução Biológica , Myxoma virus/patogenicidade , Infecções por Poxviridae/epidemiologia , Infecções por Poxviridae/patologia , Fatores de Tempo , Infecções Tumorais por Vírus/epidemiologia , Infecções Tumorais por Vírus/patologia , Virulência
2.
Ultrasound Med Biol ; 31(7): 971-7, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15972203

RESUMO

Accurate monitoring of the blood glucose level in diabetics is essential in preventing complications. Generally, conventional over-the-counter glucose meters require frequent painful finger punctures to obtain samples, which makes a noninvasive method preferable. The purpose of this study was to demonstrate that glucose levels can be measured transdermally with the combination of the low-profile cymbal array and an electrochemical glucose sensor consisting of amperometric electrodes and a novel glucose oxidase hydrogel. Interstitial fluid glucose concentrations can be determined with the electrochemical glucose sensor after the skin is made permeable to glucose by ultrasound (US) (20 kHz) with the thin (< 7 mm) and light (< 22 g) cymbal array. Using this array to deliver insulin into hyperglycemic rats, our previous experiments demonstrated that blood glucose levels would decrease 233.3 mg/dl with 5 min of US exposure. With the sensor and array, our goal was to determine the glucose levels of hyperglycemic rats noninvasively and evaluate the possible bioeffects. A total of 12 anesthetized rats were placed into two groups (US exposure group and control group) and the array (I(SPTP) = 100 mW/cm(2)) with a saline reservoir operating for 20 min was affixed to the abdomen. The array was removed and an electrochemical glucose sensor was placed on the exposed area to determine the glucose concentrations through the skin. Comparison was made using a commercial glucose meter with the blood collected from a jugular vein. The average blood glucose level determined by the sensor was 356.0 +/- 116.6 mg/dl, and the glucose level measured by the commercial glucose meter was 424.8 +/- 59.1 mg/dl. These results supported the use of this novel system consisting of the electrochemical glucose sensor and the cymbal array for glucose monitoring.


Assuntos
Técnicas Biossensoriais , Automonitorização da Glicemia/métodos , Hiperglicemia/diagnóstico , Ultrassom , Animais , Glicemia/análise , Automonitorização da Glicemia/instrumentação , Estudos de Viabilidade , Glucose Oxidase , Hidrogel de Polietilenoglicol-Dimetacrilato , Hiperglicemia/sangue , Permeabilidade , Ratos , Ratos Sprague-Dawley , Pele/patologia , Transdutores
3.
Can J Public Health ; 105(1): e53-62, 2014 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-24735698

RESUMO

OBJECTIVE: Regular HIV testing and early detection leads to timely treatment. Appropriate treatment and care can prevent disease progression in the individual and prevent onwards transmission within the community. This review describes HIV testing coverage in populations disproportionately affected by HIV and in the general population in Canada. METHODS: A search of published and grey literature on HIV testing uptake in Canada was conducted. Studies reporting quantitative data on testing practices (ever tested, recent testing, and regular testing), published in either English or French from 2008-2012, were included. Studies that involved testing for immigration or prenatal purposes, and post-intervention studies, were excluded. Included studies were assessed using a modified version of the Public Health Agency of Canada's Descriptive Study Critical Appraisal Tool. Pooled prevalence for percent ever tested was calculated for subpopulations and heterogeneity was estimated using the I2 statistic. SYNTHESIS: A total of 26 studies were included in the review. The highest rates of ever having been tested were among people who inject drugs (90.6%) and inmates (90.4%); followed by men who have sex with men (83.0%); Aboriginal peoples (55.5%); and the general population (32.8%). Limited information was available on regular and recent testing. CONCLUSION: HIV testing can reduce the number of undiagnosed cases in Canada. Future research should focus on testing coverage in certain populations, and on the extent to which populations engage in regular testing.


Assuntos
Infecções por HIV/prevenção & controle , Programas de Rastreamento/estatística & dados numéricos , Grupos Populacionais/estatística & dados numéricos , Canadá , Humanos
4.
Int J Nanomedicine ; 3(3): 335-41, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18990942

RESUMO

Prior studies have demonstrated the effectiveness of noninvasive transdermal insulin delivery using a cymbal transducer array. In this study the physiologic response to ultrasound mediated transdermal insulin delivery is compared to that of subcutaneously administered insulin. Anesthetized rats (350-550 g) were divided into four groups of four animals; one group representing ultrasound mediated insulin delivery and three representing subcutaneously administered insulin (0.15, 0.20, and 0.25 U/kg). The cymbal array was operated for 60 minutes at 20 kHz with 100 mW/cm2 spatial-peak temporal-peak intensity and a 20% duty cycle. The blood glucose level was determined at the beginning of the experiment and, following insulin administration, every 15 minutes for 90 minutes for both the ultrasound and injection groups. The change in blood glucose from baseline was compared between groups. When administered by subcutaneous injection at insulin doses of 0.15 and 0.20 U/kg, there was little change in the blood glucose levels over the 90 minute experiment. Following subcutaneous administration of insulin at a dose of 0.25 U/kg, blood glucose decreased by 190 +/- 96 mg/dl (mean +/- SD) at 90 minutes. The change in blood glucose following ultrasound mediated insulin delivery was -262 +/- 40 mg/dl at 90 minutes. As expected, the magnitude of change in blood glucose between the three injection groups was dependant on the dose of insulin administered. The change in blood glucose in the ultrasound group was greater than that observed in the injection groups suggesting that a higher effective dose of insulin was delivered.


Assuntos
Glicemia/efeitos dos fármacos , Eletroporação/métodos , Insulina/administração & dosagem , Animais , Relação Dose-Resposta a Droga , Injeções Subcutâneas , Ratos , Ratos Sprague-Dawley , Sonicação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA