Calibrated uncoupling of tightly coupled concentric surface coils for in vivo NMR

Three known active methods of detuning rf coils have been tested by determining the efficiency of uncoupling two concentric transmit surface coils in a double-coil probe. In a comparison at 80 MHz, the method based on the use of lambda/4 cables was found to have advantages. These methods utilize the introduction of an additional resonance at the frequency of interest to completely detune a coil. By offsetting the detuning of the coil (by offsetting the additional resonance) a calibrated fraction of the rf field of the detuned coil can be added to or substracted from the rf field of the neighboring coil.     

The effect of dental insurance on the demand for dental services in the USA: a review

Examines the primary studies which have contributed to dental care research. By reviewing background information, lays a foundation for the review of the current empirical evidence, which examines the effect of dental insurance coverage on the oral health of the American population, as well as the utilization and demand for dental services. Raises questions and implications for future research and practice.     

Prevalence and risk factors for latex allergy: a cross sectional study in a United Kingdom hospital

OBJECTIVES: To determine the prevalence and risk factors for symptoms related to gloves, and the relation between symptoms and immunological evidence of type 1 hypersensitivity to latex in a United Kingdom health care setting. METHODS: A cross sectional survey was carried out among 773 employees at a British hospital. A self administered questionnaire was used to collect information about symptoms related to gloves and associated risk factors in a sample of hospital staff who were likely to use gloves at work. All of those who reported symptoms suggestive of type 1 hypersensitivity were invited for skin prick testing and measurement of specific IgE to latex (RAST). RESULTS: Among the 372 responders, symptoms related to gloves were common, 49% reported redness or itching of the hands, 14% reported urticaria, and 6% reported chest tightness. However, the frequency of positive skin prick tests and RASTs was surprisingly low (only two subjects tested positive). CONCLUSIONS: These findings indicate the need for caution in the interpretation of symptoms related to gloves even when they seem to suggest type 1 hypersensitivity.

 

     

Autochthonous hepatitis E in Southwest England: natural history, complications and seasonal variation, and hepatitis E virus IgG seroprevalence in blood donors, the elderly and patients with chronic liver disease

AIMS: To report the natural history of autochthonous hepatitis E and hepatitis E virus (HEV) IgG seroprevalence in Southwest England. METHODS: Patients with unexplained hepatitis were tested for hepatitis E and cases followed until recovery or death. Five hundred blood donors, 336 individuals over the age of 60 years and 126 patients with chronic liver disease were tested for HEV IgG. RESULTS: Forty cases of autochthonous hepatitis E (genotype 3) were identified. Hepatitis E was anicteric in 25% of cases and usually caused a self-limiting hepatitis predominantly in elderly Caucasian males. Six of 40 had a significant complication and three patients died, two of who had previously undiagnosed cirrhosis. Hepatitis E shows a seasonal variation with peaks in the spring and summer and no cases in November and December. HEV IgG prevalence increases with age, is more common in men and is 16% in blood donors, 13% in patients with chronic liver disease and 25% in individuals over 60 years. CONCLUSION: Autochthonous hepatitis E is more common than previously recognized, and should be considered in the differential diagnosis in patients with hepatitis, whatever their age or travel history. It carries a significant morbidity and when seen in the context of chronic liver disease carries an adverse prognosis.     

Contrasting roles of NADPH oxidase isoforms in pressure-overload versus angiotensin II-induced cardiac hypertrophy

Increased production of reactive oxygen species (ROS) is implicated in the development of left ventricular hypertrophy (LVH). Phagocyte-type NADPH oxidases are major cardiovascular sources of ROS, and recent data indicate a pivotal role of a gp91phox-containing NADPH oxidase in angiotensin II (Ang II)-induced LVH. We investigated the role of this oxidase in pressure-overload LVH. gp91phox-/- mice and matched controls underwent chronic Ang II infusion or aortic constriction. Ang II-induced increases in NADPH oxidase activity, atrial natriuretic factor (ANF) expression, and cardiac mass were inhibited in gp91phox-/- mice, whereas aortic constriction-induced increases in cardiac mass and ANF expression were not inhibited. However, aortic constriction increased cardiac NADPH oxidase activity in both gp91phox-/- and wild-type mice. Myocardial expression of an alternative gp91phox isoform, Nox4, was upregulated after aortic constriction in gp91phox-/- mice. The antioxidant, N-acetyl-cysteine, inhibited pressure-overload-induced LVH in both gp91phox-/- and wild-type mice. These data suggest a differential response of the cardiac Nox isoforms, gp91phox and Nox4, to Ang II versus pressure overload.