Summary:Increased transport of Na + across an intact bloodbrain barrier (BBB) participates in edema formation during the early hours of cerebral ischemia. In previous studies, the authors showed that the BBB Na-K-Cl cotransporter is stimulated by factors present during ischemia, suggesting that the cotransporter may contribute to the increased brain Na + uptake in edema. The present study was conducted to determine (1) whether the Na-K-Cl cotransporter is located in the luminal membrane of the BBB, and (2) whether inhibition of the BBB cotransporter reduces brain edema formation. Perfusion-fixed rat brains were examined for cotransporter distribution by immunoelectron microscopy. Cerebral edema was evaluated in rats subjected to permanent middle cerebral artery occlusion (MCAO) by magnetic resonance diffusion-weighted imaging and calculation of apparent diffusion coefficients (ADC). The immunoelectron microscopy studies revealed a predominant (80%) luminal membrane distribution of the cotransporter. Magnetic resonance imaging studies showed ADC ratios (ipsilateral MCAO/contralateral control) ranging from 0.577 to 0.637 in cortex and striatum, indicating substantial edema formation. Intravenous bumetanide (7.6-30.4 mg/kg) given immediately before occlusion attenuated the decrease in ADC ratios for both cortex and striatum (by 40-67%), indicating reduced edema formation. Bumetanide also reduced infarct size, determined by TTC staining. These findings suggest that a luminal BBB Na-K-Cl cotransporter contributes to edema formation during cerebral ischemia. Key Words: Cotransport-Blood-brain barrier-Stroke, Cerebral ischemiaCerebral edema-Bumetanide.Brain edema that forms during the early hours of ischemic stroke involves a net uptake of Na + and water from blood into brain across an intact blood-brain barrier

ObjectiveTo examine tobacco industry marketing of menthol cigarettes and to determine what the tobacco industry knew about consumer perceptions of menthol.MethodsA snowball sampling design was used to systematically search the Legacy Tobacco Documents Library (LTDL) (http://legacy.library.ucsf.edu) between 28 February and 27 April 2010. Of the approximately 11 million documents available in the LTDL, the iterative searches returned tens of thousands of results from the major US tobacco companies and affiliated organisations. A collection of 953 documents from the 1930s to the first decade of the 21st century relevant to 1 or more of the research questions were qualitatively analysed, as follows: (1) are/were menthol cigarettes marketed with health reassurance messages? (2) What other messages come from menthol cigarette advertising? (3) How do smokers view menthol cigarettes? (4) Were menthol cigarettes marketed to specific populations?ResultsMenthol cigarettes were marketed as, and are perceived by consumers to be, healthier than non-menthol cigarettes. Menthol cigarettes are also marketed to specific social and demographic groups, including African–Americans, young people and women, and are perceived by consumers to signal social group belonging.ConclusionsThe tobacco industry knew consumers perceived menthol as healthier than non-menthol cigarettes, and this was the intent behind marketing. Marketing emphasising menthol attracts consumers who may not otherwise progress to regular smoking, including young, inexperienced users and those who find ‘regular’ cigarettes undesirable. Such marketing may also appeal to health-concerned smokers who might otherwise quit.

Multiplex short tandem repeat (STR) analysis has emerged as the dominant forensic DNA identification method because it is easy to interpret, can use sub-nanogram amounts of DNA, has a high degree of discrimination and can yield results in a matter of hours (1-3). In the United States, these advantages have led to the development of a national felon database employing 13 core STR loci (4-6). In May 2000, the PowerPlex ® 16 System (Promega, Madison, WI) was introduced as the first multiplex system capable of simultaneously amplifying all 13 core STR, the sex determinant locus, amelogenin, and two high discrimination low stutter pentanucleotide STR loci, Penta D and Penta E (7). This product was subsequently validated by a group of forensic laboratories to demonstrate concordance in approximately 2000 samples with existing STR typing systems (8,9). Previous studies have documented the allele frequencies (10) and physical mapping data (11,12) for the 15 STR loci in the PowerPlex ® 16 System. In this study we present validation data from 24 laboratories and developmental data from Promega Corporation demonstrating that the PowerPlex ® 16 System provides reliable genotyping data under a wide variety of conditions. The results obtained demonstrate the robustness of this system and the ability to successfully use the PowerPlex ® 16 System with casework samples in a large number of forensic laboratories. These studies have been performed to satisfy TWGDAM (13) and DAB guidelines in order to address concerns presented in today's legal environment. As a result of these studies, the Power-Plex ® 16 System has been approved for use in providing casework and reference sample genotypes for the CODIS/NDIS national database system.

Maintenance of a stable cell volume and intracellular pH is critical for normal cell function. Arguably, two of the most important ion transporters involved in these processes are the Na+/H+exchanger isoform 1 (NHE1) and Na+-K+-2Cl−cotransporter isoform 1 (NKCC1). Both NHE1 and NKCC1 are stimulated by cell shrinkage and by numerous other stimuli, including a wide range of hormones and growth factors, and for NHE1, intracellular acidification. Both transporters can be important regulators of cell volume, yet their activity also, directly or indirectly, affects the intracellular concentrations of Na+, Ca2+, Cl−, K+, and H+. Conversely, when either transporter responds to a stimulus other than cell shrinkage and when the driving force is directed to promote Na+entry, one consequence may be cell swelling. Thus stimulation of NHE1 and/or NKCC1 by a deviation from homeostasis of a given parameter may regulate that parameter at the expense of compromising others, a coupling that may contribute to irreversible cell damage in a number of pathophysiological conditions. This review addresses the roles of NHE1 and NKCC1 in the cellular responses to physiological and pathophysiological stress. The aim is to provide a comprehensive overview of the mechanisms and consequences of stress-induced stimulation of these transporters with focus on the heart, brain, and blood. The physiological stressors reviewed are metabolic/exercise stress, osmotic stress, and mechanical stress, conditions in which NHE1 and NKCC1 play important physiological roles. With respect to pathophysiology, the focus is on ischemia and severe hypoxia where the roles of NHE1 and NKCC1 have been widely studied yet remain controversial and incompletely elucidated.

Historically, increase in cell Na content during ischemic and hypoxic episodes were thought to result from impaired ATP production causing decreased Na(+)-K(+)-ATPase activity. Here we report the results of testing the alternate hypothesis that hypoxia-induced Na uptake is 1) the result of increased entry, as opposed to decreased extrusion 2) via Na-H exchange operating in a pH regulatory capacity and that cell Ca accumulation occurs via Na-Ca exchange secondary to collapse of the Na gradient. We used 23Na-, 19F-, and 31P-nuclear magnetic resonance (NMR) to measure intracellular Na content (Nai), Ca concentration [( Ca]i), pH (pHi), and high-energy phosphates in Langendorff-perfused rabbit hearts. When the Na(+)-K(+)-ATPase was inhibited by ouabain and/or K-free perfusion, hearts subjected to hypoxia gained Na at a rate greater than 10 times that of normoxic controls [during the first 12.5 min Nai increased from 7.9 +/- 5.8 to 34.9 +/- 11.0 (SD) meq/kg dry wt compared with 11.1 +/- 16.3 to 13.6 +/- 9.0 meq/kg dry wt, respectively]. When normoxic hearts were acidified using a 20 mM NH4Cl prepulse technique, pHi rapidly fell from 7.27 +/- 0.24 to 6.63 +/- 0.12 but returned to 7.07 +/- 0.10 within 20 min, while Na uptake was similar in rate and magnitude to that observed during hypoxia (24.5 +/- 13.4 to 132.1 +/- 17.7 meq/kg dry wt). During hypoxia and after NH4Cl washout, increases in [Ca]i were similar in time course to those observed for Na.(ABSTRACT TRUNCATED AT 250 WORDS)