Brief advice on alcohol: as easy as A...B...I?

Alcohol is widely consumed by the majority of the UK population and alcohol-related harm is estimated to cost society £21 billion per year in healthcare, lost productivity costs, crime and antisocial behaviour. The dental setting offers an ideal opportunity to screen for harmful alcohol consumption; however, current emphasis is on the management of acute complications and risk associated in treating patients with excessive alcohol intake rather than screening and patient education. This article outlines ways in which dentists could improve their recognition of 'at risk' patients and then offer practical advice to help reduce the harmful effects of alcohol.

Oxygen therapy improves cardiac index and pulmonary vascular resistance in patients with pulmonary hypertension.

STUDY OBJECTIVES: We tested the hypothesis that breathing 100% oxygen could result in selective pulmonary vasodilatation in patients with pulmonary hypertension, including those patients who would not meet current Health Care Finance Administration guidelines for long-term oxygen therapy. DESIGN, SETTING, AND PATIENTS: From 1996 to 1999, 23 adult patients (mean +/- SEM age, 51 +/- 4 years) with pulmonary arterial hypertension without left-heart failure underwent cardiac catheterization in a university teaching hospital while breathing air and then 100% oxygen. MEASUREMENTS AND RESULTS: Treatment with 100% oxygen increased arterial oxygen saturation (91 +/- 1% to 99 +/- 0.1%, p < 0.05) and PaO(2) (64 +/- 3 to 309 +/- 28 mm Hg, p < 0.05). Treatment with 100% oxygen also decreased mean pulmonary artery pressure (56 +/- 3 to 53 +/- 2 mm Hg, p < 0.05) and increased cardiac index (2.1 +/- 0.1 to 2.5 +/- 0.2 L/min/m(2), p < 0.05). Calculated mean pulmonary vascular resistance (PVR) decreased from 14.1 +/- 1.4 to 10.6 +/- 1.0 Wood units (p < 0.05). Vasodilatation with 100% oxygen occurred preferentially in the pulmonary circulation (PVR/systemic vascular resistance, 0.53 +/- 0.04 to 0.48 +/- 0.03; p < 0.05). The magnitude of the PVR response to oxygen therapy was correlated only with decreasing patient age (r = 0.45, p < 0.05). CONCLUSIONS: Treatment with 100% oxygen is a selective pulmonary vasodilator in patients with pulmonary hypertension, regardless of primary diagnosis, baseline oxygenation, or right ventricular function. Development of disease-specific oxygen prescription guidelines warrants consideration.

Negative pressure pulmonary hemorrhage.

Negative pressure pulmonary edema, a well-recognized phenomenon, is the formation of pulmonary edema following an acute upper airway obstruction (UAO). To our knowledge, diffuse alveolar hemorrhage has not been reported previously as a complication of an UAO. We describe a case of negative pressure pulmonary hemorrhage, and we propose that its etiology is stress failure, the mechanical disruption of the alveolar-capillary membrane.

Studies of perinuclear and nuclear translocation of the Raf-1 protein in rodent fibroblasts.

Raf-1, A-Raf and B-Raf comprise a small family of highly conserved serine/threonine protein kinases, whose activities play a fundamental role in the control of proliferation and differentiation. The best studied family member, Raf-1, is expressed ubiquitously and constitutively, and its activity is regulated by post-translational mechanisms. Raf-1 can be activated by many signals that include growth factors, tumor promoters, inflammatory cytokines, calcium mobilization, DNA damaging agents, and oxygen radicals. Ras-mediated translocation of Raf-1 to the plasma membrane is a crucial step in its activation process, and is thought to facilitate phosphorylation by membrane-bound kinases. Raf-1 has also been reported to undergo intracellular redistribution following its activation: to the perinuclear space in murine NIH3T3 cells and rat hepatic Ito cells, and into the nucleus in gerbil hippocampal pyramidal cells and human MO7 leukemia cells. In contrast to the translocation to the plasma membrane, the perinuclear and/or nuclear translocation of Raf-1 has not been investigated in detail. In this paper, we report an examination of the subcellular localization of endogenous Raf-1 in a fibroblastic cell line (Rat-1) commonly used in transformation assays. Using the methods of cellular fractionation as well as in situ immunofluorescence, we show that no detectable movement of Raf-1 to the perinuclear or nuclear space can be observed. Tethering of activated Raf to the plasma membrane does not interfere with its transforming activity.

Overproduction of Rb protein after the G1/S boundary causes G2 arrest.

The Rb protein is known to exert its activity at decision points in the G1 phase of the cell cycle. To investigate whether it may also play some role(s) at later points in the cell cycle, we used a system of rapid inducible gene amplification to conditionally overexpress Rb protein during G2 phase. A cell line expressing a temperature-sensitive simian virus 40 large T antigen (T-Ag) was stably transfected with plasmids containing the Rb cDNA linked to the simian virus 40 origin of replication: pRB-wt, pRB-fs, and pRB-Dra, carrying wild-type murine Rb cDNA, a frameshift mutation close to the beginning of the Rb coding region, and a single-amino-acid deletion in the E1A/T-Ag binding pocket, respectively. Numerous independent cell lines were isolated at the nonpermissive temperature; cell lines displaying a high level of episomal amplification of an intact Rb expression cassette following shiftdown to the permissive temperature were chosen for further analysis. Plasmid pRB-fs did not express detectable Rb antigen, while pRB-Dra expressed full-length Rb protein. The Dra mutation has previously been shown to abrogate phosphorylation as well as T-Ag binding. Fluorescence-activated cell sorting (FACS) analysis revealed that cultures induced to overexpress either wild-type or Dra mutant Rb proteins were significantly enriched for cells with a G2 DNA content. Cultures that amplified pRB-fs or rearranged pRB-wt and did not express Rb protein had normal cell cycle profiles. Double-label FACS analysis showed that cells overexpressing Rb or Rb-Dra proteins were uniformly accumulating in G2, whereas cells expressing endogenous levels of Rb were found throughout the cell cycle. These results indicate that Rb protein is interacting with some component(s) of the cell cycle-regulatory machinery during G2 phase.