A Combined Study of Headspace Volatiles using Human Sensory, Mass Spectrometry and Chemometrics

Smokeless tobacco products (STPs) are widely used in certain parts of the world, yet there is limited understanding of how they are consumed, particularly the impact of chemosensory characteristics on their use. In order to develop an understanding of the drivers of STP use and product acceptability we conducted both human sensory panel testing and chemical analyses on a range of STPs. Free-sorting paired odour testing using sensory panellists identified similarities and clear differences between eleven different STPs. Headspace volatiles, analysed by headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS), identified 20 to 70 components depending upon the STP. Key differences in headspace volatiles were found between STPs. For example, the headspace of Skoal Bandits Wintergreen was dominated by methyl salicylate, while Marlboro Spice consists of a more complex profile including pinene, nicotine, eugenol and cymene. Chemometric Target Factor Analysis (TFA) and Hierarchical Cluster Analysis (HCA) of chemistry and sensory data was used to deduce chemical drivers of sensory perceptions. The chemometric strategy used showed that headspace analysis is a complementary screening tool to sensory analysis in classification studies. This study is generic with applications across various product sectors that require routine human sensory panel evaluation.

Leveraging a Clinical Phase Ib Proof-of-Concept Study for the GPR40 Agonist MK-8666 in Patients With Type 2 Diabetes for Model-Informed Phase II Dose Selection

GPR40 mediates free fatty acid–induced insulin secretion in beta cells. We investigated the safety, pharmacokinetics, and glucose response of MK‐8666, a partial GPR40 agonist, after once‐daily multiple dosing in type 2 diabetes patients. This double‐blind, multisite, parallel‐group study randomized 63 patients (placebo, n = 18; 50 mg, n = 9; 150 mg, n = 18; 500 mg, n = 18) for 14‐day treatment. The results showed no serious adverse effects or treatment‐related hypoglycemia. One patient (150‐mg group) showed mild‐to‐moderate transaminitis at the end of dosing. Median MK‐8666 T_max was 2.0–2.5 h and mean apparent terminal half‐life was 22–32 h. On Day 15, MK‐8666 reduced fasting plasma glucose by 54.1 mg/dL (500 mg), 36.0 mg/dL (150 mg), and 30.8 mg/dL (50 mg) more than placebo, consistent with translational pharmacokinetic/pharmacodynamic model predictions. Maximal efficacy for longer‐term assessment is projected at 500 mg based on exposure–response analysis. In conclusion, MK‐8666 was generally well tolerated with robust glucose‐lowering efficacy.

Abstract A21: Active immunotherapy with PROSTVAC® demonstrates potent antitumor efficacy in a mouse model of prostate cancer

BN ImmunoTherapeutics (BNIT) specializes in developing novel active immunotherapies for cancer. These therapies use recombinant poxviruses engineered to express tumor-associated antigens (TAAs), with the intent of generating effective immune responses against the patients' cancer. PROSTVAC® is a candidate product for the treatment of prostate cancer for which a global Phase III clinical trial (PROSPECT) was recently initiated. This product is composed of two different viral vectors derived from a recombinant vaccinia virus (PROSTVAC™-V) and a recombinant fowlpox virus (PROSTVAC™-F). Both vectors contain transgenes encoding prostate-specific antigen (PSA) and a triad of costimulatory molecules (B7-1, ICAM-1, and LFA-3), designated as TRICOM™. Patients are immunized using a prime-boost strategy consisting of an initial treatment with PROSTVAC™-V followed by repeated boosting with PROSTVAC™-F to maximize the immune responses against the PSA tumor-antigen.

Here we show preclinical data characterizing PROSTVAC® activity in mice. Treatment with either PROSTVAC™-V or PROSTVAC™-F induced PSA-specific antibody and T cell responses; however, PSA-specific responses were further increased by the prime/boost strategy, particularly with respect to the frequency of responding CD8 T cells. These CD8 T cells produced IFN-gamma and degranulated in an antigen-specific manner. Furthermore, PROSTVAC® treatment resulted in strong efficacy in a mouse model of prostate cancer. In this model, treatment with PROSTVAC resulted in anti-tumor efficacy accompanied by a Th1-biased response against PSA. In contrast, growth of tumors in control mice induced only non-protective PSA-specific responses with strong Th2 bias.

Overall, these animal studies help define the activity and mechanism of action of PROSTVAC® which is currently being evaluated in the clinic.

R.B. Rountree and S.J. Mandl contributed equally to this work.

Citation Format: Ryan B. Rountree, Stefanie J. Mandl, Joseph Cote, Tracy dela Cruz, Thierry Giffon, Evan Gordon, Susan P. Foy, John R. Lombardo, Erica Trent, Reiner Laus, Alain Delcayre. Active immunotherapy with PROSTVAC® demonstrates potent antitumor efficacy in a mouse model of prostate cancer. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A21.

Identifying D-positive donors using a second automated testing platform

Because of the variability of D expression, one method may be inadequate to correctly classify donors with variant RHD alleles. We evaluated the use of a solid -phase automated platform (ImmucorGamma Galileo) to confirm D- test results obtained on first-time donors on the Beckman Coulter PK7300 automated microplate test system. Samples with discordant results were analyzed by serologic tube methods, RHD genotyping using the BLOODchip platform (Progenika) and, if necessary, sequencing. We estimated the number of cases of alloimmunization in women younger than 50 years likelyto be prevented by the addition of Galileo testing. From May 2011 to May 2012, 910,220 donor samples were tested; 15,441 were first-time donors with concordant D- results. Five donors tested D- on the PK7300 and weak D+ on the Galileo; one was found to be a false positive on further testing. On manual testing, the other four donors had positive indirect antiglobulin test results with one to three of the antisera used and were C+. On BLOODchip testing, two donors were classified as D+, and two were assigned a "no call". D variants included weak D type 67, weak D type 9, and two novel variants. Approximately 10 percent of D- units are transfused to women younger that 50 years. Assuming an alloimmunization rate of 30 percent, use of the Galileo would prevent approximately one alloimmunization every 5 to 6 years in this patient group. We conclude that the yield of preventing alloimmunization in this population by adding a second automated seologic testing platform is very low.

Personality-dependent dispersal: characterization, ontogeny and consequences for spatially structured populations

Dispersal is one of the most fundamental components of ecology, and affects processes as diverse as population growth, metapopulation dynamics, gene flow and adaptation. Although the act of moving from one habitat to another entails major costs to the disperser, empirical and theoretical studies suggest that these costs can be reduced by having morphological, physiological or behavioural specializations for dispersal. A few recent studies on different systems showed that individuals exhibit personality-dependent dispersal, meaning that dispersal tendency is associated with boldness, sociability or aggressiveness. Indeed, in several species, dispersers not only develop behavioural differences at the onset of dispersal, but display these behavioural characteristics through their life cycle. While personality-dependent dispersal has been demonstrated in only a few species, we believe that it is a widespread phenomenon with important ecological consequences. Here, we review the evidence for behavioural differences between dispersers and residents, to what extent they constitute personalities. We also examine how a link between personality traits and dispersal behaviours can be produced and how personality-dependent dispersal affects the dynamics of metapopulations and biological invasions. Finally, we suggest future research directions for population biologists, behavioural ecologists and conservation biologists such as how the direction and the strength of the relationship between personality traits and dispersal vary with ecological contexts.

Risky dispersal: avoiding kin competition despite uncertainty

Leaving a population without having information about the surrounding areas is highly risky. Candidates for dispersal may reduce these risks by making decisions based on the level of connectivity between patches, e.g., through immigrants. The benefits of information acquisition may vary within a population according to the dispersal cause and the phenotype of the candidate disperser. For instance, kin-based dispersers should be prepared to accept higher dispersal cost than individuals leaving for competition with congeners, and individuals of better condition should better deal with the costs of dispersing. We investigated whether the use of information obtained from immigrants depended on the reason for dispersal and the phenotype of individuals in common lizards (Lacerta vivipara). Dispersal decisions with respect to connection status depended on the cause of dispersal and on body mass. When intraspecific competition was the driving force behind dispersal, the information carried by immigrants allowed candidate dispersers to decrease uncertainty about the success of dispersal. Therefore, larger individuals dispersed when connectivity was low, whereas smaller individuals dispersed when connectivity was high. When kin competition dominated, dispersers did not adjust their dispersal decisions on the basis of information about the existence of surrounding populations, and larger individuals dispersed whatever the connectivity. These results provide support for the hypothesis that kin competition is one of the factors driving colonization.

Carotenoid-based coloration, oxidative stress and corticosterone in common lizards

Environmental factors including stressors, health status and social context significantly affect carotenoid-based coloration. For instance, stressors may induce the diversion of carotenoids from pigmentation pathways, potentially explaining why stressed animals often exhibit reduced coloration. However, we recently showed that high blood corticosterone concentrations, which are part of the physiological stress response, are associated with increased redness of the belly in the common lizard (Lacerta vivipara). This result clearly contrasts with the findings of many studies of carotenoid-based coloration because corticosterone is believed to increase oxidative stress. Here, we examined whether these positive effects are influenced by differences in food availability. We tested the effect of high corticosterone levels on carotenoid-based coloration, antioxidant enzyme activity and oxidative damage in common lizards subject to low and high food availability. Food restriction abolished the carotenoid-based color enhancement when corticosterone concentrations in animals were high. We discuss how carotenoid-based color can honestly signal individual quality in this species and how the increased redness induced by corticosterone could be a terminal investment in an environment where long-term survival prospects are poor but not when immediate survival is endangered.

Food deprivation modifies corticosterone-dependent behavioural shifts in the common lizard

Stressful events typically induce glucocorticoid production that suppresses unnecessary physiological and behavioural functions. The glucocorticoid production also temporally activates alternative behavioural and physiological pathways. These responses are generally adaptive changes to avoid the negative effects of stressors. However, under low food availability, these behavioural and physiological modifications might lead to energetic costs. We therefore predict that these responses should not be activated when there are energetic constraints (e.g., low food availability). We experimentally tested whether food deprivation modifies corticosterone-induced behavioural and physiological responses in captive male common lizards. We measured corticosterone-induced responses in terms of body mass, metabolic rate, activity level and basking behaviour. We found that corticosterone-induced various behavioural and physiological responses which were dependent on food availability. Well-fed lizards treated with corticosterone were active earlier, and increased their basking behaviour. These behavioural modifications did not occur in food-deprived lizards. This inactivation of stress-related behavioural changes probably allows the lizard to save energy.

Age-dependent allocation of carotenoids to coloration versus antioxidant defences

Aging is commonly attributed to age-related changes in oxidative damage due to an increased production of reactive oxygen species (ROS) and a weakened efficacy of enzymatic antioxidants. These age-related changes might therefore modify the use of dietary antioxidants, including carotenoids. As carotenoids are closely associated with the expression of secondary sexual signals, the allocation of carotenoids to sexual signal versus antioxidant defences may vary with age. In this study, we explored how carotenoid-based ornament and antioxidant activity varied with age and how an inflammatory-induced oxidative burst affected ornament and antioxidant activity across a range of ages. Using zebra finches (Taeniopygia guttata) as a model species, we assessed circulating carotenoids, beak coloration and the plasma antioxidant status of birds of different ages before and after an inflammatory challenge. Our results show that old individuals display similar carotenoid-based sexual signals regardless of the availability of circulating carotenoids, suggesting a terminal investment of old individuals in their last reproductive event. Additionally, we found that an inflammatory insult induced a decrease in the total antioxidant activity and in the expression of a carotenoid-based sexual signal in the oldest individuals. These results suggest that old individuals pay an extra cost of immune activation possibly because the efficiency of antioxidant machinery varies with age.

Social personality trait and fitness

Several recent studies have explored various aspects of animal personality and their ecological consequences. However, the processes responsible for the maintenance of personality variability within a population are still largely unknown. We have recently demonstrated that social personality traits exist in the common lizard (Lacerta vivipara) and that the variation in sociability provides an explanation for variable dispersal responses within a given species. However, we need to know the fitness consequences of variation in sociability across environmental contexts in order to better understand the maintenance of such variation. In order to achieve this, we investigated the relationship between sociability and survival, body growth and fecundity, in one-year-old individuals in semi-natural populations with varying density. 'Asocial' and 'social' lizards displayed different fitness outcomes in populations of different densities. Asocial lizards survived better in low-density populations, while social females reproduced better. Spatiotemporal variation in environmental conditions might thus be the process underlying the maintenance of these personality traits within a population. Finally, we also discuss the position of sociability in a more general individual behavioural pattern including boldness, exploration and aggressiveness.

Mother-offspring competition promotes colonization success

Colonization is the crucial process underlying range expansions, biological invasions, and metapopulation dynamics. Which individuals leave their natal population to colonize empty habitats is a crucial question and is presently unresolved. Dispersal is the first step in colonization. However, not all dispersing individuals are necessarily good colonizers. Indeed, in some species, the phenotype of dispersers differs depending on the selective pressures that induce dispersal. In particular, kin-based interactions, a factor driving social evolution, should induce different social response profiles in nondispersing and dispersing individuals. Kin competition (defined here as between the mother and offspring) has been proven to produce dispersers with a particular phenotype that may enhance their colonizing ability. By using the common lizard (Lacerta vivipara), we conducted a multipopulation experiment to study the effect of kin competition on dispersal and colonization success. We manipulated mother-offspring interactions, which are the most important component of kin competition in the studied species, at the family and population levels and measured the consequences on colonization success. We demonstrate that mother-offspring competition at the population level significantly influences colonization success. Increased competition at the population level enhanced the colonization rate of the largest juveniles as well as the growth and survival of the colonizers. Based on these results, we calculated that kin-induced colonization halves the extinction probability of a newly initiated population. Because interactions between relatives are likely to affect the ability of a species to track habitat modifications, kin-based dispersal should be considered in the study of invasion dynamics and metapopulation functioning.

Social information and emigration: lessons from immigrants

'Should I stay or should I go?' is a fundamental question facing any candidate for emigration, as emigrating without outside information has major costs. Most studies on this topic have concentrated on risk-reducing strategies (e.g. exploration) developed after leaving the natal habitat. The idea that information might be acquired before leaving has not been investigated. Immigrants carrying information about their origins could provide such information to potential emigrants in their initial habitat. We manipulated the density of common lizard (Lacerta vivipara) populations, to investigate whether immigrants originating from these populations transmitted such information to the population they joined. Emigration of the residents of this new population clearly depended on the origin of the immigrant. Immigrants are therefore a source of information, in this case about surrounding population densities, and may have a major effect on dispersal and species persistence in a fragmented habitat.

Social personalities influence natal dispersal in a lizard

Animal personalities are common across taxa and have important evolutionary and ecological implications. Such consistent individual differences correlate with important life-history traits such as dispersal. Indeed, some environmental conditions are supposed to determine dispersers with a specific personality. For example, an increased density should promote the departure of individuals with less social tolerance. Therefore, we hypothesized that dispersers from high-density populations should primarily be asocial individuals, whereas dispersers from low-density populations should be social individuals. In the common lizard (Lacerta vivipara), we measured attraction towards the odour of conspecifics on juveniles at birth as a metric of social tolerance. We then released these juveniles into populations of different densities and measured dispersal and settlement behaviours with regard to social tolerance. One year later, we again measured the social tolerance of surviving individuals. The social tolerance is constant across time and strongly reflects the individual's dispersal and settlement patterns with respect to population density. These results strongly suggest that social personalities exist and influence dispersal decisions. Further studies will help to elucidate the proximate and ultimate determinants of social personalities.

Experimental enhancement of corticosterone levels positively affects subsequent male survival

Corticosterone is an important hormone of the stress response that regulates physiological processes and modifies animal behavior. While it positively acts on locomotor activity, it may negatively affect reproduction and social activity. This suggests that corticosterone may promote behaviors that increase survival at the cost of reproduction. In this study, we experimentally investigate the link between corticosterone levels and survival in adult common lizards (Lacerta vivipara) by comparing corticosterone-treated with placebo-treated lizards. We experimentally show that corticosterone enhances energy expenditure, daily activity, food intake, and it modifies the behavioral time budget. Enhanced appetite of corticosterone-treated individuals compensated for increased energy expenditure and corticosterone-treated males showed increased survival. This suggests that corticosterone may promote behaviors that reduce stress and it shows that corticosterone per se does not reduce but directly or indirectly increases longer-term survival. This suggests that the production of corticosterone as a response to a stressor may be an adaptive mechanism that even controls survival.

Female common lizards (Lacerta vivipara) do not adjust their sex-biased investment in relation to the adult sex ratio

Sex allocation theory predicts that facultative maternal investment in the rare sex should be favoured by natural selection when breeders experience predictable variation in adult sex ratios (ASRs). We found significant spatial and predictable interannual changes in local ASRs within a natural population of the common lizard where the mean ASR is female-biased, thus validating the key assumptions of adaptive sex ratio models. We tested for facultative maternal investment in the rare sex during and after an experimental perturbation of the ASR by creating populations with female-biased or male-biased ASR. Mothers did not adjust their clutch sex ratio during or after the ASR perturbation, but produced sons with a higher body condition in male-biased populations. However, this differential sex allocation did not result in growth or survival differences in offspring. Our results thus contradict the predictions of adaptive models and challenge the idea that facultative investment in the rare sex might be a mechanism regulating the population sex ratio.

Test-retest reliability of DSC MRI CBV mapping in healthy volunteers

Dynamic susceptibility contrast magnetic resonance imaging (DSC MRI) can be used to generate high resolution maps of cerebral blood volume (CBV). To determine the test-retest reliability, CBV was measured in eight volunteers on two occasions, separated by 4 weeks. The mean ratio (scan 2/scan 1) for 72 cortical regions of interest (ROIs) was 1.03, with a coefficient of variation of 14%. The correlation between the first and second scans was 0.73 (p < 0.0001; 95%). In five hand-drawn ROIs, the mean ratio was 1.08, with a coefficient of variation of 12%. The correlation between scans was 0.84 (p < 0.0001). The data presented here support the hypothesis that DSC MRI CBV mapping has acceptable test-retest reliability.

Personal values and sexual decision-making among virginal and sexually experienced urban adolescent girls

PURPOSE

To guide the development of an intervention to reduce the incidence of sexually transmitted diseases (STDs) in urban, adolescent girls, we investigated such girls' reasons for deciding to have or not to have sexual intercourse.

METHODS

Consecutive girls >or=14 years of age attending an urban adolescent clinic were invited to complete an anonymous survey about sexual decision-making. In this pilot study, girls were asked: (a) whether they agreed with a statement that they had or had not had sexual intercourse "because of my values and beliefs"; and (b) to select from a list one or more specific reasons why they had or had not had intercourse. The girls were categorized by self-report as either "virgins," "currently inactive" (no intercourse in the preceding 3 months), or "currently active" (had intercourse during the preceding 3 months).

RESULTS

Usable surveys were obtained from 197 adolescents whose age (18.2 +/- 2.6 years) and race (69% black) were comparable to those of clinic attendees in general. Forty girls (20%; age 16.1 +/- 2.1 years) were virgins, 25 girls (13%; age 17.8 +/- 2.3 years) were inactive, and 132 girls (67%; age 18.9 +/- 2.5 years) were currently active. "Values and beliefs" were cited as the reason for decisions about sexual behavior by 53% of the virgins, but only by 24% of the sexually inactive and 24% of the sexually active girls (p = .002). Virgins were more likely than inactive girls to cite three specific reasons for not having sex: "not the right thing for me now" (82% vs. 50%, p = .007), "waiting until I am older" (69% vs. 8%, p = .001), and "waiting until I am married" (67% vs. 38%, p = .02). The reason "against my religious beliefs" was cited by 23% of virgins and 13% of inactive girls (p = not significant). Personal values were implicit in the two specific reasons for having sex that active girls chose most frequently, namely, "I like/love the person" (86%) and "I like having sex" (37%), although only 24% of these girls had explicitly cited "values and beliefs" as their reason for having sex.

CONCLUSIONS

Our data indicate that urban girls, both those who have had sexual intercourse and those who have not, view their sexual behavior as being based on personal (although infrequently religious) values. Many of the virginal urban, adolescent girls we surveyed hold abstinence as a personal value. The sexually active adolescents perceive the decision to have sexual intercourse as being based affirmatively on their personal values rather than on the chance occurrence of opportunities to have intercourse. These data may be useful in the development of new strategies for reducing urban adolescent girls' risk of acquiring sexually transmitted diseases.

Rofecoxib, a COX-2 inhibitor, does not inhibit human gastric mucosal prostaglandin production

BACKGROUND & AIMS

Rofecoxib, an inhibitor of the inducible cyclooxygenase (COX)-2 enzyme, appears not to cause acute gastroduodenal injury or chronic ulceration. To attribute this to COX-2 selectivity with sparing of gastric mucosal prostaglandin synthesis requires direct proof.

METHODS

Twenty-four healthy, nonsmoking Helicobacter pylori-negative volunteers were randomized to 1 of 2 separate concurrent blinded crossover studies. Sixteen volunteers received rofecoxib, 50 mg once daily, for 5 days in one treatment period and placebo in the other. Eight volunteers similarly received naproxen, 500 mg twice daily, and placebo. On day 5 of each period, antral mucosal prostaglandin E2 (PGE2) synthesis was measured by radioimmunoassay after vortexing for 3 minutes. Whole blood COX-1 activity was measured as serum thromboxane (TXB)2- and COX-2 activity as lipopolysaccharide (LPS)-induced PGE2.

RESULTS

Naproxen decreased gastric mucosal PGE2 synthesis by 65% (90% confidence interval [CI], 53%-74%; P = 0.001 vs. placebo) in contrast to an 18% increase after rofecoxib (90% CI, -11% to 57%; P = 0.313 vs. placebo). Naproxen also significantly inhibited both serum TXB2 by 94% and LPS-induced PGE2 production by 77% (both P < or = 0.002 vs. placebo), but rofecoxib only inhibited COX-2-dependent LPS-induced PGE(2) (by 79%; P < 0.001 vs. placebo).

CONCLUSIONS

Rofecoxib (50 mg) lacked naproxen's ability to reduce the availability of gastroprotective prostaglandins.

Effects of low-dose alcohol exposure on simulated merchant ship piloting by maritime cadets

The US Department of Transportation (DOT) regulates on-the-job alcohol use by operators of certain categories of commercial transport. For aircraft, trains, and commercial vessels, operators are subject to sanctions for having > or = 0.04 g% blood alcohol concentration (BAC). This study examines the effects of alcohol (between 0.04 and 0.05 g% BAC) on simulated merchant ship handling. A two-group randomized factorial design was used to compare beverage alcohol to placebo while controlling for baseline performance on a previous day. The study was conducted in the Maritime Simulation Center at Maine Maritime Academy, Castine, ME. Participants were 38 volunteer deck officer cadets in their junior or senior year, at least 21 years of age, with previous experience on a bridge simulator. Following a baseline trial on Day 1, on Day 2 participants were randomized to receive alcohol (0.6 g/kg for males and 0.5 g/kg for females) or placebo. After allowing time for absorption, participants completed a bridge simulator task. For baseline and performance trials, participants were randomized to one of four bridge simulator scenarios, each representing passage of a fully loaded container vessel through a channel with commercial traffic. The aggregate scenario score given by blinded maritime educators measured performance. A main effect for alcohol was found indicating that performance was significantly impaired by this low dose of alcohol relative to performance in the placebo condition. These findings are consistent with current federal regulations that limit low-dose alcohol exposure for the operators of commercial transport vehicles. Further research is required to determine effects at lower BACs.

The yeast NuA4 and Drosophila MSL complexes contain homologous subunits important for transcription regulation

In Drosophila, the MSL complex is required for the dosage compensation of X-linked genes in males and contains a histone acetyltransferase, MOF. A point mutation in the MOF acetyl-CoA-binding site results in male-specific lethality. Yeast Esa1p, a MOF homolog, is essential for cell cycle progression and is the catalytic subunit of the NuA4 acetyltransferase complex. Here we report that NuA4 purified from yeast with a point mutation in the acetyl-CoA-binding domain of Esa1p exhibits a strong decrease in histone acetyltransferase activity, yet has no effect on growth. We demonstrate that Eaf3p (Esa1p-associated factor-3 protein), a yeast protein homologous to the Drosophila dosage compensation protein MSL3, is also a stable component of the NuA4 complex. Unlike other subunits of the complex, it is not essential, and the deletion mutant has no growth phenotype. NuA4 purified from the mutant strain has a decreased apparent molecular mass, but retains wild-type levels of histone H4 acetyltransferase activity. The EAF3 deletion and the ESA1 mutation lead to a decrease in PHO5 gene expression; the EAF3 deletion also significantly reduces HIS4 and TRP4 expressions. These results, together with those previously obtained with both the MSL and NuA4 complexes, underscore the importance of targeted histone H4 acetylation for the gene-specific activation of transcription.

A case of giant cell hepatitis recurring after liver transplantation and treated with ribavirin

A patient who underwent orthotopic liver transplantation for giant cell hepatitis with cirrhosis and in whom giant cell hepatitis recurred twice after orthotopic liver transplantation is reported. He was treated with ribavirin with an excellent result. The literature on this subject is reviewed. This observation clearly confirms the efficacy of ribavirin for the treatment of giant cell hepatitis, thus providing evidence for its viral origin.

Aberrant splicing of tau pre-mRNA caused by intronic mutations associated with the inherited dementia frontotemporal dementia with parkinsonism linked to chromosome 17

Frontotemporal dementia accounts for a significant fraction of dementia cases. Frontotemporal dementia with parkinsonism linked to chromosome 17 is associated with either exonic or intronic mutations in the tau gene. This highlights the involvement of aberrant pre-mRNA splicing in the pathogenesis of neurodegenerative disorders. Little is known about the molecular mechanisms of the splicing defects underlying these diseases. To establish a model system for studying the role of pre-mRNA splicing in neurodegenerative diseases, we have constructed a tau minigene that reproduces tau alternative splicing in both cultured cells and in vitro biochemical assays. We demonstrate that mutations in a nonconserved intronic region of the human tau gene lead to increased splicing between exon 10 and exon 11. Systematic biochemical analyses indicate the importance of U1 snRNP and, to a lesser extent, U6 snRNP in differentially recognizing wild-type versus intron mutant tau pre-mRNAs. Gel mobility shift assays with purified U1 snRNP and oligonucleotide-directed RNase H cleavage experiments support the idea that the intronic mutations destabilize a stem-loop structure that sequesters the 5' splice site downstream of exon 10 in tau pre-mRNA, leading to increases in U1 snRNP binding and in splicing between exon 10 and exon 11. Thus, mutations in nonconserved intronic regions that increase rather than decrease alternative splicing can be an important pathogenic mechanism for the development of human diseases.

Effects of low-dose alcohol exposure on simulated merchant ship handling power plant operation by maritime cadets

AIMS

Under current US Department of Transportation (DOT) regulations, some commercial vehicle operators are subject to sanctions for having > or = 00.04 g% blood alcohol concentrations (BACs) on the job. This study investigated the effects of alcohol (between 0.04 and 0.05 g% BAC) on the simulated operation of a commercial ship's power plant.

DESIGN

A balanced placebo design was used in which alcohol administration was fully crossed with expectancy that alcohol was administrated.

SETTING

The study was conducted at the Massachusetts Maritime Academy, Buzzards Bay, MA, USA.

PARTICIPANTS

Participants were 18 volunteer engineering students in their senior year, at least 21 years of age, with previous experience on the diesel simulator.

INTERVENTION

Following a baseline trial on day 1, on day 2 participants were randomized to expectancy (told alcohol or placebo) and beverage (receive alcohol or placebo). The dosage was 0.6 g/kg for males and 0.5 g/kg for females. In both baseline and performance days, participants were randomized to one of four diesel simulator scenarios, each replicating a system failure in a power plant subsystem (e.g. main propulsion, electrical generating).

MEASUREMENT

Performance was measured by time required for problem identification and remediation.

FINDINGS

A main effect for alcohol administration was found. In the alcohol condition, simulator performance time was almost twice as long (351 sec) as on the placebo condition (186 sec). The expectancy effect was not significant.

CONCLUSION

These findings support the current federal policy on the hazards of this low alcohol level within the context of commercial shipping.

Employee drinking practices and work performance

OBJECTIVE

The purpose of this study was to examine the independent effects of a variety of drinking indicators on self-reported work performance.

METHOD

Data from a cross-sectional mailed survey (response rate = 71%) of managers, supervisors and workers (N = 6,540) at 16 worksites were analyzed. Average daily volume was computed from frequency and usual quantity reports. Drinking on the job included drinking during any of six workday situations. The CAGE was used to indicate alcohol dependence. Employees were also asked how frequently they drank to get high or drunk. Work performance was measured through a series of questions about work problems during the prior year. The number of times respondents experienced work performance problems was regressed on the four drinking measures, and a variety of demographic characteristics, job characteristics and life circumstances that might also negatively affect work performance.

RESULTS

The frequency of self-reported work performance problems increased, generally, with all four drinking measures. In a multivariate model that controlled for a number of demographics, job characteristics and life-situations, average daily volume was no longer significantly associated with work performance but the other three drinking measures were. Interestingly, although moderate-heavy and heavy drinkers reported more work performance problems than very light, light, or moderate drinkers, the lower-level-drinking employees, since they were more plentiful, accounted for a larger proportion of work performance problems than did the heavier drinking groups.

CONCLUSIONS

Employers should develop clear policies limiting drinking on the job and, in addition to employee assistance programs for problem drinkers, should develop worksite educational interventions aimed at informing all employees about the relationship between drinking behaviors and work performance.

Did changes in minimum age drinking laws affect adolescent drowning (1970-90)?

OBJECTIVE

To test the hypothesis that changes in the minimum legal drinking age (MLDA) laws would affect drowning among adolescents, the effects of changes in state MLDA laws on drowning were examined for the targeted (18-20 years) and two adjacent (15-17 years and 21-23 years) age groups, over a period of 21 years (1970-90).

METHODS

Poisson maximum likelihood regression was used to estimate the effects of both lowering and increasing the MLDA. The dependent variable in these analyses was the number of drownings per state per year for the age groups observed. At first only state and year effects were controlled for and then any other variable potentially associated with the incidence of drowning was included. The other control variables included proportion of population living near border states with lower MLDA laws, urbanicity, unemployment, divorce, education, poverty, beer tax, and proxy measures for MLDA law enforcement.

RESULTS

No significant association between drowning and MLDA was found for any of the age groups studied.

CONCLUSION

It is concluded that MLDA laws are not an important public policy strategy for affecting drowning rates among adolescents and young adults.

TOM1p, a yeast hect-domain protein which mediates transcriptional regulation through the ADA/SAGA coactivator complexes

The hect-domain has been characterized as a conserved feature of a group of E3 ubiquitin ligases. Here we show that the yeast hect-domain protein TOM1p regulates transcriptional activation through effects on the ADA transcriptional coactivator proteins. Null mutations of tom1 result in similar defects in transcription from ADH2 and HIS3 promoters, and enhanced transcription from the GAL10 promoter as do null mutations in ngg1/ada3. Strains with disruptions of both ngg1 and tom1 have the same phenotype as strains with a disruption of only ngg1 implying that these genes are acting through the same pathway. In the absence of TOM1p, the normal associations of the ADA proteins with SPT3p and the TATA-binding protein are reduced. The action of TOM1p is most likely mediated through ubiquitination since mutation of Cys3235 to Ala, corresponding residues of which are required for thioester bond formation with ubiquitin in other hect-domain proteins, results in similar changes in transcription as the null mutation. A direct role for TOM1p in regulation of ADA-associated proteins is further supported by the finding that SPT7p is ubiquitinated in a TOM1p-dependent fashion and that TOM1p coimmunoprecipitates with the ADA proteins.

Covariates of fear of falling and associated activity curtailment

With a sample survey (N = 266) of elderly adults residing in six housing developments in Massachusetts, we used logistic regression to: (a) identify covariates of fear of falling among all subjects and (b) identify covariates of activity curtailment among the subset of subjects who were afraid of falling. Fifty-five percent of respondents were afraid of falling; of those who were afraid, 56% had curtailed activity due to this fear. Factors associated with fear of falling were: being female, having had previous falls, and having fewer social contacts. Factors associated with activity curtailment among those who were afraid were: not communicating about falls; having less social support; and knowing someone who had fallen. Falls history appears an important contributor to fear of falling, whereas the impact of this fear on activities appears more a function of social support. These findings suggest different strategies for the primary and secondary prevention of fear of falling.

An international validation of the interaction with disabled persons scale

The Interaction with Disabled Persons Scale (IDP) was devised to measure attitudes in terms of discomfort reported about social interaction with people with disabilities. The Scale has been used in Australia for ten years. This article reports results of an international validation project that was designed to determine whether psychometric characteristics and norms emerging for Australian groups apply elsewhere. A methodological proforma was developed to maximize uniformity of data collection across nine countries: Australia, Canada, Croatia, England, Germany, Hong Kong, Poland, Scotland and the United States. In most countries the Scale was administered in English; however it also was translated into Germany, Polish, French and Croat. Results indicate that across countries mean scores fell within ten points, similar moderate to high levels of item homogeneity occurred and level of prior contact with people with disabilities emerged as the strongest predictor of IDP scores. It was concluded that the IDP Scale is a valid measure that is able to discriminate between respondents within the countries included in the study.

Patients' perceptions of outcomes of a Canadian hospitalization

Notes that with health care reform moving at tremendous speed throughout Canada, a great deal of interest in outcomes research has been generated. States that the research team consisted of 17 professional practice leaders from eight disciplines. Proposes, through the research, to identify from the perspective of former patients what results they hoped to achieve prior to discharge from hospital and what facilitated and hindered them in achieving these results. Reports that a representative sample was selected for the study. Forty-one former patients each participated in up to two focus groups, with a total of 16 focus groups conducted. Hierarchical analysis revealed themes that fell within the framework of structure, process and outcomes. The findings will assist in ensuring that more appropriate and effective care is offered to patients by a variety of disciplines.