IntroductionTobacco cigarette smoking a well-known cause of cancer and other diseases. Hookah smoking is another form of tobacco use that has rapidly spread in the United State and Europe. This study assessed beliefs about the harmfulness of smoking hookah.MethodsWe surveyed hookah users in all cafes that provided hookah to its customers in downtown San Diego, California and nearby areas. A total of 235 hookah users participated in this study.ResultsAverage age of study participants was 22 years, 57% were males, and 72% were not cigarette smokers. Whites were more likely to use hookah than the other ethnic groups (33%), older hookah users (26-35 years) were mostly males, and mint flavor of hookah tobacco was the most popular among a wide variety of flavors (23%). There was no significant difference in gender in relation to the wrong perception that hookah is less harmful than cigarettes, but those of Asian ethnicity were much less likely than other ethnic groups to believe that hookah is less harmful than cigarettes. More frequent users of hookah were more likely to believe that hookah is less harmful than cigarettes. The majority of hookah users (58.3%) believe hookah is less harmful than cigarette smoking.DiscussionCompared to cigarettes, there appears to be a lack of knowledge about the harmfulness of smoking hookah among users regardless of their demographic background. Education about the harmfulness of smoking hookah and policies to limit its use should be implemented to prevent the spread of this new form of tobacco use.

Quantitative T 2 relaxation and diffusion imaging studies of a rat muscle edema model were performed in order to determine the effects of intra-and extracellular water compartmentation on the respective decay curves. The right hind paw of rats was injected with a carrageenan solution to generate edematous muscle. A Carr-Purcell-Meiboom-Gill (CPMG) imaging sequence was used to acquire T 2 relaxation decay curves from both paws. A line scan diffusion imaging (LSDI) sequence was then used to acquire diffusion decay curves from the same paws over a wide b-factor range. Measurements were made from both edematous muscle (EM) and control muscle (CM). The EM and CM T 2 relaxation decay curves were best fit with biexponential functions. The fraction of the fast T 2 component dropped dramatically from approximately 0.95 in CM to 0.45 in EM, consistent with a water compartmentation model in which the fast and slow T 2 components reflect intra-and extracellular water, respectively. Both CM and EM diffusion decay curves required biexponential fitting functions, and the diffusion coefficients of the fast and slow components were substantially larger in EM than CM. The fraction of the fast diffusion component, however, was not radically altered between CM and EM conditions (0.84 versus 0.89 for CM versus EM). Assuming a model in which intra-and extracellular water compartments are responsible for the fast and slow T 2 -decay components and for the slow and fast diffusion decay components, respectively, leads to fractional sizes of the diffusion components that are not supported by experiment. We conclude that intra-and extracellular water compartmentation is a reasonable interpretation for the two T 2 -decay components in both CM and EM but that other factors, such as restricted diffusion and/or alternate forms of water compartmentation like surface versus volume water, most probably have profound influences on the precise shapes of the diffusion decay curves, a complete understanding of which will require significant theoretical work. The sensitivity of proton relaxation and diffusion measurements to the chemical and physical environment of water molecules has long been exploited for studying the organization and distribution of water in living tissues. Early transverse relaxation time, T 2 , studies performed with non-imaging based Carr-Purcell-Meiboom-Gill (CPMG) sequences (1) or Hahn spin echo sequences (2) on tissue specimens often described the T 2 relaxation decay curves as non-monoexponential in nature and well-suited to multiexponential analyses, with the components generally interpreted in terms of different water compartments with some contributions from macromolecules, particularly for the very short T 2 components (3-10). Most imaging studies of T 2 relaxation with magnetic resonance imaging scanners, however, have been performed with more stringent limitations on minimal echo spacings due to the need for frequency encoded readouts. Also, unless specifically optimized for single slice imaging, measurements are oft...

The increase in T(2) of skeletal muscle after exercise is correlated with the increase of the diffusion coefficient D and the recovery times appear similar, indicating that any model used to explain T(2) increases with exercise must also account for increased diffusion coefficients.

Bupivacaine and tetrodotoxin, via a contralateral or ipsilateral sciatic block, attenuate local inflammatory edema and hyperalgesia induced by hind paw injection of carrageenan in rats. Mechanisms underlying contralateral effects of sciatic blockade remain unexplained. Bupivacaine inhibits carrageenan-evoked systemic cytokine production by a mechanism not shared by tetrodotoxin; this action may involve tetrodotoxin-resistant sodium channels or a variety of non-sodium-channel targets.