Interactions of ingested food, beverage, and tobacco components involving human cytochrome P4501A2, 2A6, 2E1, and 3A4 enzymes

Human cytochrome P450 (P450) enzymes are involved in the oxidation of natural products found in foods, beverages, and tobacco products and their catalytic activities can also be modulated by components of the materials. The microsomal activation of aflatoxin B1 to the exo-3,9-epoxide is stimulated by flavone and 7,8-benzoflavone, and attenuated by the flavonoid naringenin, a major component of grapefruit. P4502E1 has been demonstrated to play a potentially major role in the activation of a number of very low-molecular weight cancer suspects, including ethyl carbamate (urethan), which is present in alcoholic beverages and particularly stone brandies. The enzyme (P4502E1) is also known to be inducible by ethanol. Tobacco contains a large number of potential carcinogens. In human liver microsomes a significant role for P4501A2 can be demonstrated in the activation of cigarette smoke condensate. Some of the genotoxicity may be due to arylamines. P4501A2 is also inhibited by components of crude cigarette smoke condensate. The tobacco-specific nitrosamines are activated by a number of P450 enzymes. Of those known to be present in human liver, P4501A2, 2A6, and 2E1 can activate these nitrosamines to genotoxic products.

Identification of theta-class glutathione S-transferase in liver cytosol of the marmoset monkey

The presence of theta-class glutathione S-transferase (GST) in marmoset monkey liver cytosol was investigated. An anti-peptide antibody targeted against the C-terminus of rGSTT1 reacted with a single band in marmoset liver cytosol that corresponded to a molecular weight of 28 kDa. The intensity of the immunoreactive band was not affected by treatment of marmoset monkeys with 2,3,7,8-tetrachlorodibenzo-p-dioxin, phenobarbitone, rifampicin or clofibric acid. Similarly, activity towards methyl chloride (MC) was unaffected by these treatments. However, GST activity towards 1,2-epoxy3-(p- nitrophenoxy)-propane (EPNP) was increased in marmosets treated with phenobarbitone (2.6-fold) and rifampicin (2.6-fold), activity towards dichloromethane (DCM) was increased by 50% after treatment of marmosets with clofibric acid, and activity towards 1-chloro-2,4-dinitrobenzene (CDNB) was raised slightly (30-42% increases) after treatment with phenobarbitone, rifampicin or clofibric acid. Compared with humans, marmoset liver cytosol GST activity towards DCM was 18-fold higher, activity towards MC was 7 times higher and activity towards CDNB was 4 times higher. Further, EPNP activity was clearly detectable in marmoset liver cytosol samples, but was undetectable in human samples. Immunoreactive marmoset GST was partially purified by affinity chromatography using hexylglutathione-Sepharose and Orange A resin. The interaction of immunoreactive marmoset GST was similar to that found previously for rat and human GSTT1, suggesting that this protein is also a theta class GST. However, unlike rat GSTT1, the marmoset enzyme was not the major catalyst of EPNP conjugation. Instead, immunoreactivity was closely associated with activity towards MC. In conclusion, these results provide evidence for the presence of theta-class GST in the marmoset monkey orthologous to rGSTT1 and hGSTT1.

Progesterone regulation of implantation-related genes: new insights into the role of oestrogen

Genomic profiling was performed on explants of late proliferative phase human endometrium after 24-h treatment with progesterone (P) or oestradiol and progesterone (17 beta-E-2+P) and on explants of menstrual phase endometrium treated with 17 beta-E-2+P. Gene expression was validated with real-time PCR in the samples used for the arrays, in endometrium collected from early and mid-secretory phase endometrium, and in additional experiments performed on new samples collected in the menstrual and late proliferative phase. The results show that late proliferative phase human endometrium is more responsive to progestins than menstrual phase endometrium, that the expression of several genes associated with embryo implantation (i.e. thrombomodulin, monoamine oxidase A, SPARC-like 1) can be induced by P in vitro, and that genes that are fully dependent on the continuous presence of 17 beta-E-2 during P exposure can be distinguished from those that are P-dependent to a lesser extent. Therefore, 17 beta-E-2 selectively primes implantation-related genes for the effects of P.

Recognising emotional expressions of complaining customers : A cross-cultural study

Purpose This study aims to test service providers’ ability to recognise non-verbal emotions in complaining customers of same and different cultures. Design/methodology/approach In a laboratory study, using a between-subjects experimental design (n = 153), we tested the accuracy of service providers’ perceptions of the emotional expressions of anger, fear, shame and happiness of customers from varying cultural backgrounds. After viewing video vignettes of customers complaining (with the audio removed), participants (in the role of service providers) assessed the emotional state of the customers portrayed in the video. Findings Service providers in culturally mismatched dyads were prone to misreading anger, happiness and shame expressed by dissatisfied customers. Happiness was misread in the displayed emotions of both dyads. Anger was recognisable in the Anglo customers but not Confucian Asian, while Anglo service providers misread both shame and happiness in Confucian Asian customers. Research limitations/implications The study was conducted in the laboratory and was based solely on participant’s perceptions of actors’ non-verbal facial expressions in a single encounter. Practical implications Given the level of ethnic differences in developed nations, a culturally sensitive workplace is needed to foster effective functioning of service employee teams. Ability to understand cultural display rules and to recognise and interpret emotions is an important skill for people working in direct contact with customers. Originality/value This research addresses the lack of empirical evidence for the recognition of customer emotions by service providers and the impact of cross-cultural differences.

Positive magnetic resonance imaging findings in the asymptomatic wrist

BACKGROUND: Magnetic resonance imaging (MRI) is being increasingly utilized to define pathology and guide treatment in patients presenting with wrist pain. The clinical relevance of MRI identified or confirmed pathology has not been established, and the prevalence of asymptomatic MRI pathology is not known. METHODS: Twenty volunteers with no previous wrist injury or symptoms underwent bilateral MRI wrist studies in this exploratory diagnostic study. The scans were reported by an experienced musculoskeletal radiologist and an experienced wrist surgeon, with a consensus reached on each report. RESULTS: There were 3.15 positive MRI findings per wrist. There were 126 positive findings (range 1-6 per wrist). Sixty-eight ganglia were identified. Eleven ligament tears or perforations were also identified. Increased joint fluid was seen at many sites, most frequently adjacent to the piso-triquetral joint. CONCLUSION: The accuracy of MRI in identifying triangular fibrocartilage complex tears, intercarpal ligament tears and carpal bone osteonecrosis is rapidly being refined. Positive MRI findings are common and may be coincidental in patients with wrist pain. MRI findings need to be correlated closely with clinical examination and history.

Quantification of gammaH2AX foci in response to ionising radiation

DNA double-strand breaks (DSBs), which are induced by either endogenous metabolic processes or by exogenous sources, are one of the most critical DNA lesions with respect to survival and preservation of genomic integrity. An early response to the induction of DSBs is phosphorylation of the H2A histone variant, H2AX, at the serine-139 residue, in the highly conserved C-terminal SQEY motif, forming gammaH2AX(1). Following induction of DSBs, H2AX is rapidly phosphorylated by the phosphatidyl-inosito 3-kinase (PIKK) family of proteins, ataxia telangiectasia mutated (ATM), DNA-protein kinase catalytic subunit and ATM and RAD3-related (ATR)(2). Typically, only a few base-pairs (bp) are implicated in a DSB, however, there is significant signal amplification, given the importance of chromatin modifications in DNA damage signalling and repair. Phosphorylation of H2AX mediated predominantly by ATM spreads to adjacent areas of chromatin, affecting approximately 0.03% of total cellular H2AX per DSB(2,3). This corresponds to phosphorylation of approximately 2000 H2AX molecules spanning approximately 2 Mbp regions of chromatin surrounding the site of the DSB and results in the formation of discrete gammaH2AX foci which can be easily visualized and quantitated by immunofluorescence microscopy(2). The loss of gammaH2AX at DSB reflects repair, however, there is some controversy as to what defines complete repair of DSBs; it has been proposed that rejoining of both strands of DNA is adequate however, it has also been suggested that re-instatement of the original chromatin state of compaction is necessary(4-8). The disappearence of gammaH2AX involves at least in part, dephosphorylation by phosphatases, phosphatase 2A and phosphatase 4C(5,6). Further, removal of gammaH2AX by redistribution involving histone exchange with H2A.Z has been implicated(7,8). Importantly, the quantitative analysis of gammaH2AX foci has led to a wide range of applications in medical and nuclear research. Here, we demonstrate the most commonly used immunofluorescence method for evaluation of initial DNA damage by detection and quantitation of gammaH2AX foci in gamma-irradiated adherent human keratinocytes(9)

CoWs, Google and online possibilities : creating digital posters to enhance student engagement

A new Bachelor of Science (BSc) course was introduced at Queensland University of Technology (QUT) in 2013 and focused on inquiry-based, collaborative and active learning. Two of the first year units required that students carry out a group poster assessment task. This poster provides a preliminary evaluation from an academic staff perspective of the assessment approach used, whereby students created digital posters to utilise the affordances of new learning spaces. The digital posters approach was first introduced to a group of academic staff from the Science and Engineering Faculty (SEF) in 2012 during a professional development program to explicitly develop skills and shared understandings of teaching in collaborative learning spaces (Steel & Andrews, 2012). Considerations were given to the pedagogical requirements of a poster assessment task, the affordances of the learning space and an identification of possible benefits of using Google Sites to create digital posters. Positive feedback from this group (as highlighted in the quotes shown) and subsequent approval from unit coordinators for two of the new first year BSc units meant that the approach was adopted for Semester 1, 2013 with approximately 360 students in each unit.

Hybrid CuTCNQ/AgTCNQ metal-organic charge transfer complexes via galvanic replacement vs. corrosion recrystallization

This study reports a hybrid of two metal-organic semiconductors that are based on organic charge transfer complexes of 7,7,8,8-tetracyanoquinodimethane (TCNQ). It is shown that the spontaneous reaction between semiconducting microrods of CuTCNQ with Ag+ ions leads to the formation of a CuTCNQ/AgTCNQ hybrid, both in aqueous solution and acetonitrile, albeit with completely different reaction mechanisms. In an aqueous environment, the reaction proceeds by a complex galvanic replacement (GR) mechanism, wherein in addition to AgTCNQ nanowires, Ag0 nanoparticles and Cu(OH)2 crystals decorate the surface of CuTCNQ microrods. Conversely, in acetonitrile, a GR mechanism is found to be thermodynamically unfavorable and instead a corrosion-recrystallization mechanism leads to the decoration of CuTCNQ microrods with AgTCNQ nanoplates, resulting in a pure CuTCNQ/AgTCNQ hybrid metal-organic charge transfer complex. While hybrids of two different inorganic semiconductors are regularly reported, this report pioneers the formation of a hybrid involving two metal-organic semiconductors that will expand the scope of TCNQ-based charge transfer complexes for improved catalysis, sensing, electronics and biological applications.

Epidemiology and risk factors of oral cancer in South Africa

Head and neck cancers are some of the leading cancers in the coloured and black South African male population and the perception exists that the incidence rates are rising. Aims: To determine the standardised morbidity rates and some of the risk factors for oral cancer in South Africa. Methods: Using histologically verified data from the National Cancer Registry, the age standardised incidence rates (ASIR) and life-time risks (LR) of oral cancer in South Africa were calculated for 1988-1991.2. In an ongoing case control study (1995 +) among black patients in Johannesburg/Soweto, adjusted odds ratios for developing oral cancers in relation to tobacco and alcohol consumption were calculated. Results: Coloured males vs. females: ASIR 13.13 vs. 3.5 (/100,000/year), LR 1:65 vs. 1:244. Black males vs. females: ASIR 9.06 vs. 1.75, LR 1:86 and 1:455. White males vs. females: ASIR 8.06 vs. 3.18, LR 1:104 vs. 1:278. Asian males vs. females: ASIR 5.24 vs. 6.66, LR 1:161 vs. 1:125. The odds ratio for oral cancer in black males in relation to smoking was 7.0 (95% CI 3.0-14.6) and daily alcohol consumption 1.3 (95% CI 0.6-2.8). In black females the odds ratios in relation to smoking were 3.9 (95% CI 1.7 8.9) and daily alcohol consumption 1.7(95% CI 0.7-4.1). Conclusions: The risk factors for oral cancer in South Africa are multiple and gender discrepancies in ASIR and LR signal differences in exposure to carcinogens. It is unclear whether the incidence of oral cancers will rise in the future.

All Anglos are alike? A study of whinging Poms and bloody-minded Aussies

Cross-cultural service research is an important topic with a rich array of empirical evidence for differences in customer perceptions, attitudes and behaviours. However, the extant literature is almost exclusively focused on differences between cultures at each end of the diversity spectrum (most commonly East vs. West). Contemporary researchers have observed that existing studies fail to acknowledge the substantially greater levels of intra-cluster variation that exist. A cultural cluster is a group of countries that reflect values, attitudes and beliefs stemming from a common cultural ancestry. This seems surprising given the anecdotal evidence and stereotypes that are portrayed in popular culture, media and art. One area where intra-cluster variation may be evident is consumer complaint behaviour and in particular within the Anglo-cultural cluster in countries. A cultural cluster is a group of countries that reflect values, attitudes and beliefs stemming from a common cultural ancestry. The aim of this study is therefore to explore and elucidate the nature of differences in consumer complaint behaviour between cultures traditionally conceived and operationalised as identical. This study presents a qualitative study of 60 in-depth interviews with consumers in the United Kingdom and Australia and identifies differences in complaining styles, parental influence and the conceptualisation of complaining.

Estimating the burden of disease attributable to low fruit and vegetable intake in South Africa in 2000

Objectives To estimate the burden of disease attributed to low fruit and vegetable intake by sex and age group in South Africa for the year 2000. Design The analysis follows the World Health Organization comparative risk assessment (CRA) methodology. Populationattributable fractions were calculated from South African prevalence data from dietary surveys and applied to the revised South African burden of disease estimates for 2000. A theoretical maximum distribution of 600 g per day for fruit and vegetable intake was chosen. Monte Carlo simulationmodelling techniques were used for uncertainty analysis. Setting South Africa. Subjects Adults ≥ 15 years. Outcome measures Mortality and disability-adjusted life years (DALYs), from ischaemic heart disease, ischaemic stroke, lung cancer, gastric cancer, colorectal cancer and oesophageal cancer. Results Low fruit and vegetable intake accounted for 3.2% of total deaths and 1.1% of the 16.2 million attributable DALYs. For both males and females the largest proportion of total years of healthy life lost attributed to low fruit and vegetable intake was for ischaemic heart disease (60.6% and 52.2%, respectively). Ischaemic stroke accounted for 17.8% of attributable DALYs for males and 32.7% for females. For the related cancers, the leading attributable DALYs for men and women were oesophageal cancer (9.8% and 7.0%, respectively) and lung cancer (7.8% and 4.7%, respectively). Conclusions A high intake of fruit and vegetables can make a significant contribution to decreasing mortality from certain diseases. The challenge lies in creating the environment that facilitates changes in dietary habits such as the increased intake of fruit and vegetables.

Optical gas sensing properties of nanoporous Nb2O5 films

Nanoporous Nb2O5 has been previously demonstrated to be a viable electrochromic material with strong intercalation characteristics. Despite showing such promising properties, its potential for optical gas sensing applications, which involves the production of ionic species such as H+, has yet to be explored. Nanoporous Nb2O5 can accommodate a large amount of H+ ions in a process that results in an energy bandgap change of the material, which induces an optical response. Here, we demonstrate the optical hydrogen gas (H¬2) sensing capability of nanoporous anodic Nb2O5 with a large surface-to-volume ratio prepared via a high temperature anodization method. The large active surface area of the film provides enhanced pathways for efficient hydrogen adsorption and dissociation, which are facilitated by a thin layer of Pt catalyst. We show that the process of H2 sensing causes optical modulations that are investigated in terms of response magnitudes and dynamics. The optical modulations induced by the intercalation process and sensing properties of nanoporous anodic Nb2O5 shown in this work can potentially be used for future optical gas sensing systems.

The National Stroke Nursing Council: A nursing call for action

Nursing is fundamental to the care of stroke patients. From the acute setting all the way to rehabilitation and community reintegration, nursing is there. Having well-educated and highly skilled nurses to monitor and care for stroke patients is crucial. Equally important is the collaboration of colleagues at a national level to facilitate and disseminate research and best practice guidelines across Canada. The National Stroke Nursing Council aims to fill this role. Stroke nurses from across Canada were invited to a national forum in 2005, hosted by the Canadian Stroke Network. The focus of this forum was to elucidate issues of concern to nurses across the stroke care continuum in relation to a Canadian Stroke Strategy. Subsequent to this forum, a cadre of nurses, after undergoing a rigorous screening process, were selected to form the inaugural National Stroke Nursing Council (NSNC). With ongoing support from the Canadian Stroke Network, the mandate of the NSNC is to promote leadership, communication, advocacy, education and nursing research in the field of stroke.

Rip, mix, burn: The politics of peer to peer and copyright law

Whereas Lessig's recent work engages with questions of culture and creativity in society, this paper looks at the role of culture and creativity in the law. The paper evaluates the Napster, DeCSS, Felten and Sklyarov litigation in terms of the new social, legal, economic and cultural relations being produced. This involves a deep discussion of law's economic relations, and the implications of this for litigation strategy. The paper concludes with a critique of recent attempts to define copyright law in terms of first amendment rights and communicative freedom.