The DASH diet and blood pressure

High blood pressure (also called hypertension) is one of the most important and common risk factors for atherosclerotic cardiovascular disease (CVD) and other chronic diseases. National guidelines recommend that all individuals with blood pressure readings of 120/80 mm Hg or higher adopt healthy lifestyle habits, including the Dietary Approaches to Stop Hypertension (DASH) diet, to manage their blood pressure. The DASH diet, which is high in fruits, vegetables, and low-fat dairy products and reduced in fat, has been shown in large, randomized, controlled trials to reduce blood pressure significantly. The DASH diet also has been shown to reduce blood cholesterol and homocysteine levels and to enhance the benefits of antihypertensive drug therapy. The DASH diet should be promoted, along with maintaining healthy weight, reducing sodium intake, increasing regular physical activity, and limiting alcohol intake, for lowering blood pressure and reducing the risk of CVD.     

Fibreoptic tracheal intubation after placement of the laryngeal tube

Background. The laryngeal tube is a new alternative for securingthe airway. After adequate oxygenation, insertion of a trachealtube is still required in many situations. In such circumstances,fibreoptic placement of a tube exchange catheter after placementof the laryngeal tube is possible before tracheal intubation.Throughout the procedure, oxygen administration can continuevia the laryngeal tube, the tube exchange catheter and the trachealtube. Methods. The feasibility of this technique was tested in 10patients scheduled for elective surgery. Results. The laryngeal tube was placed at the first attemptwith adequate ventilation in all patients. The tube exchangemanoeuvre was performed successfully in all but one patient. Conclusion. This technique is an important alternative for airwaymanagement and provides a significant degree of patient safety. Br J Anaesth 2002; 89: 733–8     

Fulminant radiation-induced necrosis after stereotactic radiation therapy to the posterior fossa. Case report and review of the literature

The problem of radiation-induced necrosis of normal brain surrounding the target area has been a major catalyst for the development of stereotactically focused radiation therapy. According to current opinion, the effects of stereotactic irradiation are confined to the region targeted. The authors present a case in which the administration of a conventional dose of stereotactically focused irradiation for treatment of a pilocytic astrocytoma produced fulminant necrosis that necessitated a combination of intensive surgical and medical management, after which the patient improved over the course of 1 year. Concomitant with his improvement, the initially remarkable findings on magnetic resonance imaging gradually resolved. In this presentation the authors emphasize the need to evaluate alternatives carefully before a decision is made to administer therapeutic irradiation. Furthermore, they explore the roles that target, host, and dosage factors play in hypersensitivity to radiation injury, the detection of these factors before treatment, and the administration of radioprotective agents. With the growing use of stereotactically focused irradiation as a primary treatment modality for a variety of neurosurgical conditions, it is important to be cognizant of its uncommon but potentially lethal side effects. A cooperative multicenter database in which the outcomes and morbidity following stereotactic irradiation are recorded is essential to the detection of relatively uncommon but severe complications such as those observed in this case.     

Loss of tumor-promoting activity of unleaded gasoline in N- nitrosodiethylamine-initiated ovariectomized B6C3F1 mouse liver

Unleaded gasoline (UG) vapor (2056 ppm) increased the incidence of liver tumors in a chronic bioassay and exhibited tumor-promoting activity in N-nitrosodiethylamine (DEN)-initiated female mouse liver. Estrogen inhibited mouse liver tumor development and the hepatocarcinogenic and tumor-promoting dose of UG produced uterine changes suggestive of estrogen antagonism. To directly test the hypothesis that UG-induced tumor-promoting ability is secondary to its interaction with the mouse liver tumor inhibitor, estrogen, we compared the tumor-promoting ability of UG in ovariectomized (Ovex) mice with the hepatic tumor-promoting ability of UG in intact mice. Ovaries were surgically removed at 4 weeks of age. Exposure to wholly vaporized UG (2018 ppm) under bioassay and tumor-promoting conditions began at 8 weeks of age. After 4 months of exposure, UG increased relative liver weight and hepatic microsomal cytochrome P450 pentoxyresourfin-O- dealkylase and ethoxyresorufin-O-deethylase activity to a similar extent in intact and Ovex mice. Non-focal hepatocyte proliferation, as measured by the incorporation of bromo-deoxyuridine, was not changed by UG exposure and was similar in all treatment groups. After 4 months of exposure to DEN-initiated mice, UG significantly increased the volume fraction of liver occupied by foci (three-fold) as compared to control intact mice. As expected, volume of foci was elevated in DEN/Ovex/control mice as compared to DEN/intact/control mice. In DEN/Ovex mice UG did not significantly increase the focal volume fraction. Thus, the tumor promoting activity of UG, as demonstrated by increased volume fraction of liver occupied by hepatic foci in intact mice, is greatly attenuated in Ovex mice. The volume fraction data in Ovex mice support the hypothesis that the tumor promoting activity of UG is dependent upon the interaction of UG with ovarian hormones. These data also indicate that hepatic microsomal cytochrome P450 PROD and EROD induction, hepatomegaly and non-focal hepatic LI are not specific markers of hepatic tumor promoting activity of UG.