bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutritional influences on the expression of genotypic resistance to gastrointestinal nematode infection in sheep
Authors: Walkden-Brown S. W. , Eady S. J.
Published: December 2003

This paper reviews experiments investigating the responses of resistant and susceptible genotypes of sheep to gastrointestinal nematode infection under differential nutrition. Using faecal egg count as a measure of host resistance, differences between genotypes appeared to be greatest under conditions of low nutrient availability and under such conditions both resistant and susceptible genotypes generally responded to supplemental protein by reducing faecal egg count. However, when nutritional conditions were moderate to good, responses to additional protein tended to be observed only in susceptible genotypes. In general, host genetic resistance was associated with reliable reductions in faecal egg count of moderate to large magnitude, while nutritional intervention was less reliable at reducing faecal egg count, and induced reductions of smaller magnitude. The situation was very different when examining host resilience to infection, as determined by sheep productivity in the face of infection. Increased host resistance was rarely associated with improved growth or production during the period of infection. In contrast, nutritional supplementation reliably increased host productivity irrespective of infection status and prevailing nutritional conditions. A general model of the relationship between nutrient availability and host resistance and resilience in resistant and susceptible genotypes is postulated. Taken together, the studies reviewed in this paper suggest that selection for host resistance and strategic nutritional intervention have complementary roles in the integrated control of gastrointestinal nematode infection in sheep. The former will contribute primarily to the epidemiology of the disease by reliably reducing faecal egg output over a wide range of conditions, reducing host challenge and the number of treatment interventions required. The latter will reliably boost host resilience to infection, with lesser effects on resistance, and the economic rationale for use will require accounting for the full spectrum of production and disease responses.
Principles of nutrient partitioning for wool, growth and reproduction: implications for nematode parasitism
Authors: Adams N. R. , Liu S. M.
Published: December 2003

The capacity of sheep to withstand and repel intestinal parasites is a neglected component of effective parasite control. The immune response is strongly influenced by the nutritional status of the sheep. However, we are unable take advantage of this to develop effective control programs because we have neither an adequate understanding nor appropriate quantitative data on the impacts of protein and energy on sheep nutrition. This paper reviews some aspects of current knowledge about the impact on immune responsiveness of nutrient flows within the animal as well as hormonal partitioning mechanisms, and assesses research needs in this area.
The availability of nutrients to the immune response in the gut is determined by the supply of nutrients to the sheep from both feed intake and body reserves, and the demands of other physiological processes such as growth, wool growth, pregnancy or lactation. Hormones coordinate nutrient flow among these processes. Breakdowns in immunity appear most severe when animals are faced with a demand for growth or lactation, but no single partitioning mechanism can explain all the observations in the field. Therefore, it is unrealistic to seek to establish a hierarchy of partitioning priorities. Protein appears to have a greater impact on immune responsiveness to parasites than energy. However, energy affects the availability of amino acids through a number of mechanisms including protein deposition and mobilisation, so protein supply cannot be considered in isolation. It is appealing to believe that specific limiting nutrients such as sulfur amino acids might explain the relationship between susceptibility to parasites and wool growth, but the experimental evidence for this view is still inconclusive. Rather, it appears that the total flow of nutrients from feed intake and body reserves is more important than specific partitioning mechanisms, or specific limiting nutrients. The potential conflict between role of the gut as a source of mobilisable protein reserves, and the need for protein in the gut to develop local immune responses, need to be explored experimentally.
Practical applications of nutritional knowledge are likely to come through improved timing of management procedures rather than better supplements, which are rarely economic. The conclusions outline a number of research questions that must be answered before we can develop programs that integrate immune competence with drenching and other procedures in a holistic way.
Nutritional programming of young sheep to improve later-life production and resistance to nematode parasites: a brief review
Authors: Knox M. R. , Deng K. , Nolan J. V.
Published: December 2003

Nutritional supplementation, particularly with high quality protein, can increase the resistance and resilience of sheep to infection with gastrointestinal nematode parasites. Nonetheless, this approach to improved nematode parasite control has not been widely adopted, probably because the cost of supplements is usually greater than the immediate production benefits that are conferred. Evidence is presented to support the proposition that long-term effects on liveweight, wool production, reproductive performance and immunity to nematode infection can be programmed through strategic supplementation of sheep during periods of nutritional scarcity. Where optimal efficiency of lifetime production is desired, particular attention should be paid to ensuring that nutritional needs are met and negative impacts of nematode parasitism are minimised during lactation and around the time of weaning.
Dynamics in 0+ recruitment and early life history for snapper (Pagrus
auratus, Sparidae) in South Australia
Authors: Fowler A. J. , Jennings P. R.
Published: December 2003

The population dynamics of snapper (Pagrus auratus) relate to interannual variation in 0+ recruitment. The focus of the present study was to improve our understanding of this variation for snapper in northern Spencer Gulf, South Australia. The objectives of this study were to describe the distribution and abundance of 0+ juveniles annually from 2000 to 2002 and to determine early life history characteristics through retrospective analysis of otolith microstructure from captured fish. The environmental characteristics differed between years, with 2001 being extremely hot and 2002 the coldest summer recorded. Sampling was undertaken in April after spawning and settlement were complete. The estimates of recruitment were relatively low, suggesting a complex relationship with sea surface temperature. Each year new recruits occurred at the same places that were bare and flat with muddy substratum, suggesting nursery areas are actively selected by the recruits. The sagittae from juveniles had clear daily increments and settlement mark, allowing age and presettlement duration to be determined. Growth rates varied considerably both within and between years, and were related to water temperature, which affected the presettlement duration. Based on spawn dates, successful recruitment resulted from specific periods through the reproductive season that appeared to relate to the specific water temperature regimen in each year.
Spatial and temporal variability in the distribution and diet of the gudgeon (Eleotridae: Hypseleotris spp.) in a subtropical Australian reservoir
Authors: Meredith Shaun N. , Matveev Vladimir F. , Mayes Paul
Published: December 2003

The diurnal distribution and diet of Hypseleotris spp. was examined over a 14-month period in Maroon Dam, a productive subtropical reservoir in south-east Queensland, Australia. Three distinct size classes of Hypseleotris were observed. The smallest (<16 mm standard length (SL)) fish undertake a vertical diurnal migration in the pelagic throughout the year, spending daylight hours near the surface and night hours in deeper waters. The diet of this size class consists almost exclusively of zooplankton (98.6% total prey volume), with cladocera and copepoda dominating the identifiable prey items. A larger (12–20 mm SL) size class group of subadult/adult fish occupies the near-shore littoral throughout the daylight hours but moves out of the sampled area during the night. The diet of this size class is more diverse (zooplankton 58.5%, macro-invertebrate 25.0%, other 16.5%). The largest size class (>20 mm SL) of adult Hypseleotris remains in the near-shore littoral throughout seasonal and diurnal cycles and has a more eclectic diet than the other two size classes (zooplankton 28.8%, macro-invertebrate 28.9%, other 42.3%). Spatial and temporal differences in the distribution and diet of these three size class groups are discussed with reference to the abundance and availability of suitable prey, intraspecific competitive exclusion, predator avoidance and water quality.
Interactions between fur seals and a squid jig fishery in southern Australia
Authors: Arnould J. P. Y. , Trinder D. M. , McKinley C. P.
Published: December 2003

Interactions between Australian fur seals (Arctocephalus pusillus doriferus) and the Southern Squid Jig Fishery (SSJF) were investigated in April–May 2002. Details on the number of seals present, distance from the vessel, age and gender, and their behaviour were recorded using scan sampling techniques over 26 nights from eight vessels operating out of Portland and Port Fairy on the southwest coast of Victoria. Seals were observed on all nights but none were recorded in 30% of all (777) scan observations. Of the seals attending vessels at any one time (1.89 ± 0.24), 67% were involved in activities unrelated to jigging operations with the most common behaviour category being resting/grooming. Only 3.6% of observations involved seals targeting squid caught on jig lures whereas a further 29% were of foraging on squid within 40 m of the vessel. Damage to fishing gear attributable to seals was recorded on only three occasions. There was no evidence of negative impacts on seals from vessel operations. The majority of seals foraging on squid around vessels were adult females (71%) with the remainder being almost exclusively juvenile males. The current level of interactions between Australian fur seals and vessels in the SSJF appears minor.
Circular versus longitudinal myometrial contractile response to selective tachykinin receptor agonists in rat
Authors: Williams M. J. , Hamlin G. P. , Nimmo A. J. , Crane L. H.
Published: December 2003

This study compared the nature and magnitude of the contractile response produced in vitro by selective NK1, NK2 and NK3 tachykinin receptor agonists in circularly and longitudinally oriented strips of myometrium from ovariectomised and ovariectomised oestrogen-treated rats. The nature of the responses produced upon stimulation of the tachykinin receptors varied between the different myometrial preparations and the hormonal environment from which the tissue was taken. Variations included: (i) sustained contraction until washout of agonist; (ii) biphasic contraction until washout of agonist; and (iii) monophasic contraction. The major differences in magnitude of contractions were seen in preparations from oestrogen-treated animals in which responses to stimulation of all tachykinin receptors were reduced in comparison to preparations from non-oestrogen treated animals. Furthermore, the responses in circularly oriented myometrium preparations from oestrogen-treated animals were all markedly reduced compared to responses in longitudinally oriented myometrium preparations. These results suggest that the tachykinin receptors in longitudinally and circularly oriented myometrial layers are differentially regulated, especially in tissue isolated from an oestrogen-dominated environment.
Effect of ovariectomy and graft position on cryopreserved common wombat (Vombatus ursinus) ovarian tissue following xenografting to nude mice
Authors: Cleary M. , Paris M. C. J. , Shaw J. , Jenkin G. , Trounson A.
Published: December 2003

Ovarian tissue xenografting may be applied to increase the population size of rare or endangered animals. However, optimal grafting conditions, such as graft position and recipient hormonal status, are yet to be established. The present study, using common wombat ovarian tissue, showed that development of xenografted ovarian tissue to the antral follicle stage can be achieved irrespective of graft position. However, increased graft recovery rates and follicle survival were evident after grafting under the kidney capsule compared with grafting to subcutaneous sites. No increase in follicle development was observed after placing grafts both under the kidney capsule and subcutaneously in the one recipient compared with grafts placed under the kidney capsule alone or subcutaneously alone. Removal of the recipient’s own ovaries at the time of grafting accelerated graft follicle development, with antral follicles seen by Week 12 after grafting compared with by Week 16 in recipients that retained their own ovaries. More oocytes were collected from xenograft recipients receiving hormonal stimulation before collection compared with non-stimulated recipients. No oocytes were mature (extruded a polar body) at the time of collection or after a subsequent period of in vitro maturation. This is the first study to demonstrate that antral follicle development can occur and oocytes can be collected from xenografted common wombat ovarian tissue.
The reproduction and diet of Egernia kingii (Reptilia : Scincidae) on Penguin Island, Western Australia
Authors: Arena P. C. , Wooller R. D.
Published: December 2003

A population of King's Skinks, Egernia kingii, a large (220 g) scincid lizard, on Penguin Island, near Perth, Western Australia, contained mainly adults. Males were sexually mature at a snout–vent length of 190 mm and females at 185 mm. The sexes were similar in most dimensions, but males had proportionately wider heads than females. Females ovulated in late November and gave birth in mid–late April, after a 20–22-week gestation. Most litters comprised 4–6 (range 2–8) young that averaged 7�g and had a snout–vent length of 60–80 mm. Growth to adult size appeared slow and juvenile mortality heavy, so that most adults are probably long-lived. King's skinks were active throughout the year and consumed mainly soft plant material from the range of plants available, supplemented by insects and seabird eggs.
Breeding behaviour and ecology of the sexually size-dimorphic brown songlark, Cinclorhamphus cruralis
Authors: Magrath Michael J. L. , Brouwer Lyanne , Petersen Arnoud Van , Berg Mathew L. , Komdeur Jan
Published: December 2003

The Australian endemic brown songlark, Cinclorhamphus cruralis, is one of the most sexually size-dimorphic of all birds, and yet its breeding ecology remains poorly documented. Here we redress this situation by describing the breeding activities of brown songlarks over three years (1998–2000) in the semi-arid grasslands of south-western New South Wales. Study populations of this nomadic species were selected in late August of each year on the basis of high adult abundance. Adult males at these sites were, on average, 2.3 times heavier than females. Over the three seasons, nesting activities started in early to late August and continued until early November or December. Males were highly polygynous and, on average, occupied territories of about 4.0 ha. Nests were well concealed at the base of small shrubs and grass tussocks or in thick herbage. Clutches ranged in size from 2 to 5 eggs (mean 3.2) and were incubated exclusively by the female for 11–13 days (mean 12.1). Nestlings received a range of invertebrate prey, mainly from the female, for 10–14 days (mean 11.5) before leaving the nest. Only 17% of nesting attempts were estimated to be successful, and each of these nests produced an average of 2.7 fledglings. Predators, including foxes, Vulpes vulpes, and brown snakes, Pseudonaja textilis, were the main cause of nest failure. Some females produced replacement clutches following nest failure, while others laid second clutches after the success of an earlier brood. We speculate that extreme size dimorphism has evolved in this species because (i) males compete physically for breeding territories, and (ii) habitat heterogeneity and excellent visibility of their surroundings allow some males to defend territories of sufficient size to support nesting by multiple females.
Effects of Media Formats on Emotions and Impulse Buying Intent
Authors: Adelaar Thomas , Chang Susan , Lancendorfer Karen M. , Lee Byoungkwan , Morimoto Mariko
Published: December 2003

One way of generating revenue from broadband media content rests upon the assumption that multi-media content may trigger a greater intent to buy products and services impulsively. An experiment was performed in order to explore the effects of media formats on the emotions and impulse buying intentions for music compact discs (CDs). Three distinct media formats of World Wide Web pages were set up: (1) the text of the lyrics, (2) still images from the song's music video and (3) the music video itself. Each had a varying degree of visual/ verbal intensity while simultaneously playing the soundtrack in all three conditions. The results of this study indicate that displaying the text of the lyrics had a greater effect on the impulse buying intent than showing still images of the music video. In addition, different media formats caused emotional responses that can explain the participant's impulse buying intent to buy the CD. Unexpectedly, the still images and video did not necessarily generate more buying intention than combinations of the text and music. Therefore, it is recommended that electronic commerce and marketing managers explore innovative ways of integrating visual and verbal media formats for eliciting an effective consumer response.
Developing Frameworks for Examining Community Participation in a Multi-Level Environment
Authors: Smith Mike , Sullivan Helen
Published: December 2003

The purpose of this paper is to explore public participation from the perspective of two parallel developments in English urban governance since 1997: namely the attempts to modernise local government and area-based approaches employed to tackle social exclusion. The paper will situate these developments within a system of multi-level governance and highlight the significance of the locality-neighbourhood axis. The paper seeks to explicate current changes by drawing on theories of governance. The emphasis on mechanisms that bring together relevant local interests to secure coherence and stability in matters of local governance, combined with the specific focus on the role of citizens and communities as key partners in these arrangements resonates strongly with the key concerns of regime theory. The strengths and limitations of regime theory are discussed with particular reference to matters of contextual specificity. Community Governance is then introduced as a means of better understanding the institutional framework of English localities and, we argue, of providing a sounder basis for the application of regime theory. More powerful still is the potential synthesis of regime approaches with different interpretations of community governance and the paper concludes by drawing on recent developments in English localities to elaborate the potential offered by the this synthesised framework.
Moray Revisited: High-Priority Affective Stimuli and Visual Search
Authors: Harris Christine R. , Pashler Harold E. , Coburn Pashler
Published: December 2003

Previous research offers conflicting suggestions about whether “high-priority” verbal stimuli such as an individual's own name or emotionally charged words automatically grab attention and/or can be detected without the usual capacity limitations. Nine experiments investigated this issue, using visual search through displays of words. In speeded search tasks, the subject's own name was detected more quickly than other targets, but in no case were search slopes flat enough to suggest parallel search or “pop-out”. Further, names were not found to be unusually potent distractors. Emotionally charged words were neither more readily detected as targets nor more potent as distractors than neutral words. Acomparison of observers’ accuracy in searching briefly exposed simultaneous vs. successive displays provided further evidence that search for “high-priority” word targets is subject to the same severe capacity limitations as those that are found with search for neutral words.
Differential Effects of Prime–Probe Duration on Positive and Negative Location Priming: Evidence for Opponent Facilitatory and Inhibitory Influences in Priming Tasks
Authors: Gibbons Henning , Rammsayer Thomas H.
Published: December 2003

A series of four spatial localization experiments is reported that examined the effects of display duration and presentation mode on positive and negative priming using an attended-repetition and an ignored-repetition paradigm, respectively. Experiment 1 showed larger positive priming with response-dependent than with 150 ms display durations while negative priming remained unaffected. Experiments 2–4 were performed to further elucidate the effects of prime–probe durations. Data suggest largely independent effects of prime and probe duration on priming effects. Manipulation of prime duration affected facilitation due to repetition of the prime distractor location as well as inhibitory effects associated with ignored repetition. Furthermore, anticipated probe duration modulated the effectiveness of inhibition of return. Findings are discussed within a framework proposing two major components of priming effects—a stimulus-driven or automatic component, and a strategic component related to the participant's expectations towards the probe.
Environmental Context-Dependent Recognition Memory Effects: An Examination of ICE Model and Cue-Overload Hypotheses
Authors: Rutherford A.
Published: December 2003

The ICE model account (e.g., Murnane & Phelps, 1993; Murnane, Phelps, & Malmberg, 1999) of environmental context (EC)-dependent recognition memory is described, and new predictions concerning the effect of multiple presentation ECs are derived. Experiment 1 tested the ICE model predictions in relation to predictions derived from the cue-overload hypothesis (e.g., Watkins, 1979). In addition, the sensitivity of recognition reaction time (RT) as a measure of EC-dependent memory effects was examined. Minimal support was obtained for the ICE model, but greater support was provided for the cue-overload hypothesis. In Experiment 2, further manipulations were employed to test ICE model predictions and the cue-overload hypothesis, with relevance to the mental reinstatement and outshining hypotheses. Again support for the cue-overload hypothesis was obtained, and an EC reinstatement effect with RTs was detected. The ICE model is considered in respect of these findings.
Verbal Working Memory and on-Line Syntactic Processing: Evidence from self-Paced Listening
Authors: Waters Gloria S. , Caplan David
Published: December 2003

Two experiments investigated the relationship between performance on standard tests of verbal working-memory and the on-line construction of syntactic form. In Experiment 1, working-memory was measured in 100 college students on a version of the Daneman and Carpenter (1980) reading-span task, and online syntactic processing was assessed using a self-paced listening task with four sentence types. In Experiment 2, working-memory was measured in 48 college students on two versions of the reading-span task and two other tests of verbal working-memory, and on-line syntactic processing was assessed using the self-paced listening task with an additional sentence type. In both experiments, there was no relationship between working-memory capacity and the increase in processing time seen for the on-line construction of syntactic form for either syntactically more complex or syntactically simpler sentences. The results indicate that the capacity of the working-memory system that is measured by standard working-memory tests does not determine the efficiency of on-line syntactic processing. They are consistent with the view that the working-memory system used for parsing is at least partially separate from that measured by traditional measures of working-memory capacity.
Neuro‐linguistic programming and learning theory: a response
Authors: Tosey Paul , Mathison Jane
Published: December 2003

In an earlier issue of this journal, Craft (2001) explored Neuro‐linguistic Programming (NLP) in relation to a classification of learning theories. Craft also offered various observations on, and criticisms of, aspects of NLP such as its theoretical coherence, modelling, Dilts’s ‘logical levels’ and possible dissonance of NLP’s espousal of individuality in learning with its experiential emphasis. This article offers a response to Craft’s article. It describes the origins and nature of NLP, and explores its theoretical identity. NLP is portrayed here as based primarily on the cybernetic epistemology of Gregory Bateson (1972, 1979). The article offers a critique of many of the views put across in Craft’s article, and builds on her attempt to position NLP theoretically. The broad aims of this article are to offer an informed perspective on the nature of NLP; to extend the academic literature on NLP; and to develop debate about its relevance to the theory and practice of education.
Development of a structured generic drug intervention model for public health purposes: a brief application of motivational interviewing with young people
Authors: MCCAMBRIDGE JIM , STRANG JOHN
Published: December 2003

Brief applications of Motivational Interviewing (MI) emerged around 15 years ago to target problematic alcohol and other drug use. Interventions which specifically target illicit drug use, young people, or which are delivered in settings other than health‐care services have, however, been relatively slow to develop. The needs of young people for interventions distinct from those offered to adults are considered, as a precursor to an outline of the structure of a newly adapted intervention targeting drug use in general among young people. Based upon earlier topic‐based approaches developed by Rollnick et al. this intervention is innovative in simultaneously targeting a range of drugs in pursuit of secondary prevention objectives, while also seeking to manifest the spirit of MI. The intervention consists of a single‐session face‐to‐face conversation of up to 60 minutes duration. Data are presented which describe the development and conduct of this intervention during the course of an efficacy trial, with promising efficacy data themselves reported elsewhere. Observations are made on intervention delivery and consideration is given to implications for further novel targeting of young people and within the field of addiction interventions more generally.
Antagonist‐precipitated heroin withdrawal under anaesthetic prior to maintenance naltrexone treatment: determinants of withdrawal severity
Authors: ALI ROBERT , THOMAS PETER , WHITE JASON , MCGREGOR CATHERINE , DANZ CATHERINE , GOWING LINDA , STEGINK AMANDA , ATHANASOS PETER
Published: December 2003

This study sought to characterize antagonist‐precipitated heroin withdrawal during and immediately following anaesthesia and to identify the determinants of withdrawal severity and duration in 48 dependent heroin users. Objective withdrawal signs decreased significantly with each naloxone bolus administered under anaesthetic. The cost (amount) of the final heroin administration and the number of hours between last heroin use and commencement of anaesthesia were significant, independent predictors of the severity of withdrawal symptomatology. While 83% (40/48) of participants completed withdrawal according to objective criteria and commenced maintenance naltrexone treatment, almost half (22/48) were unable to commence naltrexone on the day of the procedure due to residual withdrawal signs. Fourteen of these 22 participants subsequently commenced naltrexone (median number of days between admission and commencement of naltrexone was 2, range 1–6) while eight left treatment prior to initiation of naltrexone. Significantly fewer of those with more severe withdrawal signs during anaesthesia commenced naltrexone (40% vs. 60%). While the severity and duration of withdrawal symptomatology may be moderated by encouraging participants to reduce (or cease) heroin use close to the time of withdrawal, for a substantial proportion of participants in this study, heroin withdrawal by this antagonist‐precipitated procedure was neither rapid nor painless.
Emergency management of inadvertent accelerated opiate withdrawal in dependent opiate users
Authors: LUBMAN DAN I. , KOUTSOGIANNIS ZEFF , KRONBORG IAN
Published: December 2003

Six opiate‐dependent drug users presented to the local emergency department within a 10‐day period with symptoms of severe opioid withdrawal immediately following intravenous use of recently acquired street ‘heroin’. The withdrawal picture was similar to that described in patients undergoing rapid opioid detoxification, suggesting that the substance injected was contaminated with an opiate antagonist. A number of potential compounds are discussed, including naltrexone and buprenorphine, and recommendations for the medical management of severe opiate withdrawal within an emergency setting are outlined.
Smoking cessation interventions for in‐patients: a selective review with recommendations for hospital‐based health professionals
Authors: WOLFENDEN LUKE , CAMPBELL ELIZABETH , WALSH RAOUL A. , WIGGERS JOHN
Published: December 2003

A selective review of the literature was conducted to provide evidence‐based recommendations for the clinical management of hospitalized smokers. The Cochrane library, in particular the Cochrane review of ‘Interventions for smoking cessation in hospitalised patients’, was the basis for the review and was supplemented with other clinical and non‐clinical literature where the review did not inform clinicians sufficiently. Evidence was reviewed on issues considered by the authors to be of importance to health professionals interested in providing a smoking cessation intervention to their patients. The review suggests that effective hospital interventions: incorporate an in‐patient intervention lasting greater than 20 minutes in duration with extended post discharge follow‐up; consist of at least five intervention contacts; and be delivered over at least a 3‐month period. Furthermore, interventions should include in‐patient advice and counselling, the provision of nicotine replacement therapy and extended proactive post discharge telephone support. The review also indicates that cessation interventions are particularly effective when delivered to patients with a cardiovascular diagnosis. All health professionals may be effective in providing cessation treatments; however, the addition of a specialist smoking cessation counsellor appears to improve interventions in this setting. Finally, without the development of supportive systems, routine intervention with smoking patients by health professionals is unlikely. Recommendations for the delivery of effective smoking cessation interventions in hospitals are provided.
Being stoned: a review of self‐reported cannabis effects
Authors: GREEN BOB , KAVANAGH DAVID , YOUNG ROSS
Published: December 2003

Although there has been considerable research into the adverse effects of cannabis, less attention has been directed toward subjective effects that may be associated with ongoing cannabis use. Examination of self‐reported cannabis effects is an important issue in understanding the widespread use of cannabis. While reviews have identified euphoria as a primary factor in maintaining cannabis use, relaxation is the effect reported most commonly in naturalistic studies of cannabis users, irrespective of the method used. Self‐reported effects in 12 naturalistic and 18 laboratory studies were compared. Regardless of methodology there was considerable variation in the effects experienced. Variation has been reported in terms of opposite effects being experienced by different individuals, variation of effects by individuals within a single occasion and between occasions of use. Factors that might explain this variation are outlined. Limitations of the available literature and suggested directions for future research are discussed.
Suppression of tumor necrosis factor‐alpha‐induced neutrophil adherence responses by essential oils
Authors: Abe Shigeru , Maruyama Naho , Hayama Kazumi , Ishibashi Hiroko , Inoue Shigeharu , Oshima Haruyuki , Yamaguchi Hideyo
Published: December 2003

Background: In aromatherapy, essential oils are used as anti‐inflammatory remedies, but experimental studies on their action mechanisms are very limited.

Aims: To assess their anti‐inflammatory activities, effects of essential oils on neutrophil activation were examined in vitro.

Methods: Neutrophil activation was measured by tumor necrosis factor‐alpha (TNF‐α)‐induced adherence reaction of human peripheral neutrophils.

Results: All essential oils tested at 0.1% concentration suppressed TNF‐α‐induced neutrophil adherence, and, in particular, lemongrass, geranium and spearmint oils clearly lowered the reaction even at 0.0125%. Similar inhibitory activities for the neutrophil adherence were obtained by their major constituent terpenoids: citral, geraniol, citronellol and carvone. In contrast, very popular essential oils, tea tree oil and lavender oil, did not display the inhibitory activity at the concentration.

Conclusion: Thus, some essential oils used as anti‐inflammatory remedies suppress neutrophil activation by TNF‐α at a low concentration (0.0125‐0.025%) in vitro.
Cytomegalovirus Infection Modulates Cellular Immunity in an Experimental Model for Autoimmune Diabetes
Authors: van der Werf Nienke , Hillebrands Jan-Luuk , Klatter Flip A. , Bos Ineke , Bruggeman Cathrien A. , Rozing Jan
Published: December 2003

Background: Viral infections are thought to play a role in the development of autoimmune diseases like type 1 diabetes. In this study we investigated the effect of Rat Cytomegalovirus (RCMV) infection on cellular immunity in a well‐defined animal model for diabetes, the Biobreeding (BB) rat.

Methods: Diabetes prone (DP)‐ and Diabetes resistant (DR)‐BB rats were infected with 2 × 106 plaque forming units (pfu) RCMV. Diabetes development was monitored by frequent blood‐glucose analysis. Effects of RCMV on CD4+, CD8+ and Vβ‐TCR+ T‐cell subsets were measured in vivo, and in vitro after restimulation with RCMV‐infected fibroblasts. Proliferative capacity was determined by 3H‐Thymidine incorporation.

Results: RCMV‐infection resulted in a significant acceleration of diabetes onset in DP‐BB rats ( p=0.003). Percentages CD4+ and CD8+ T‐cells were not affected in vivo. In vitro, RCMV‐restimulation resulted in a decreased CD4+/CD8+ blastoid T‐cell ratio compared to ConA ( p=0.00028). Furthermore, RCMV‐restimulation resulted in a strong RCMV‐specific proliferation, which comprises about 50% of the response triggered by ConA. Vβ‐TCR percentages did not change upon RCMV‐infection or RCMV‐restimulation.

Interpretation: RCMV‐restimulation of splenic T‐cells in vitro resulted in a strong RCMV‐specific proliferation, probably also including autoreactive T‐cells. In vivo, this polyclonal response might be involved in the observed accelerated diabetes development in DP‐BB rats upon RCMV‐infection.
Effects of Air Pollutants on Development of Allergic Immune Responses in the Respiratory Tract
Authors: Gershwin Laurel J.
Published: December 2003

The increased incidence of allergic asthma in the human population worldwide has stimulated many explanatory theories. A concomitant decrease in air quality leads to epidemiological and laboratory‐based studies to demonstrate a link between air pollutants and asthma. Specifically, ozone, environmental tobacco smoke, and diesel exhaust are associated with enhancement of respiratory allergy to inhaled allergens. This review summarizes the state of the knowledge, both human epidemiology and laboratory animal experiments, linking air pollution to allergy. Critical issues involve development of the lung and the fetal immune response, and the potential for substances like ozone and ETS in the air to modulate early immune responses with lifelong consequences.
Expression of the HPV16E7 Oncoprotein by Thymic Epithelium is Accompanied by Disrupted T Cell Maturation and a Failure of the Thymus to Involute with Age
Authors: Malcolm K. M. , Gill J. , Leggatt G. R. , Boyd R. , Lambert P. , Frazer I. H.
Published: December 2003

Transgenic mice expressing the E7 protein of HPV16 from the keratin 14 promoter demonstrate increasing thymic hypertrophy with age. This hypertrophy is associated with increased absolute numbers of all thymocyte types, and with increased cortical and medullary cellularity. In the thymic medulla, increased compartmentalization of the major thymic stromal cell types and expansion of thymic epithelial cell population is observed. Neither an increased rate of immature thymocyte division nor a decreased rate of immature thymocyte death was able to account for the observed hypertrophy.

Thymocytes with reduced levels of expression of CD4 and/or CD8 were more abundant in transgenic (tg) mice and became increasingly more so with age. These thymic SP and DP populations with reduced levels of CD4 and/or CD8 markers had a lower rate of apoptosis in the tg than in the non‐tg mice. The rate of export of mature thymocytes to peripheral lymphoid organs was less in tg animals relative to the pool of available mature cells, particularly for the increasingly abundant CD4lo population. We therefore suggest that mature thymocytes that would normally die in the thymus gradually accumulated in E7 transgenic animals, perhaps as a consequence of exposure to a hypertrophied E7‐expressing thymic epithelium or to factors secreted by this expanded thymic stromal cell population. The K14E7 transgenic mouse thus provides a unique model to study effects of the thymic epithelial cell compartment on thymus development and involution.
Ablation of NK Cell Function During Tumor Growth Favors Type 2‐Associated Macrophages, Leading to Suppressed CTL Generation
Authors: Geldhof Anja B. , van Ginderachter Jo A. , Liu Yuanqing , Noël Wim , de Baetselier Patrick
Published: December 2003

Several reports describe regulatory interactions between NK cells and CTLs. We addressed the issue of NK participation in the early anti‐tumor defense by inoculating α‐ASGM‐1 treated mice with BW‐Sp3 T lymphoma. Rejection of BW‐Sp3 depends on strong CTL responses. Our results demonstrated that (i) NK cells are a prerequisite for efficient CTL generation and (ii) the absence of NK cells favors the outgrowth of alternatively activated macrophages that can suppress CTL restimulation. In vitro studies demonstrate that in splenic cultures from NK‐deficient, tumor‐bearing mice, the presence of alternatively activated macrophages correlates with a lack of Type 1 cytokines, while the production of Type 2 cytokines is promoted. Provision of the Type 1 cytokine, IFN‐γ can boost overall CTL activity but does not revert the dominance of arginase producing adherent cells in the NK‐deficient CTL cultures. The role of NK effector functions in the efficient switch of the immune system towards Type 1 activation was evaluated in cytotoxicity assays. The results indicate that the accessory function of NK can depend at least partially on their ability to preferentially engage arginase‐producing cells, suggesting that NK/macrophage lytic interactions might be involved in the switch from Type 2 to Type 1‐dependent immune responses.
Appearance of Human Plasma Cells Following Differentiation of Human B Cells in NOD/SCID Mouse Spleen
Authors: Kikuchi Kentaro , Lian Zhe-Xiong , He Xiao-Song , Ansari Aftab A. , Ishibashi Miyuki , Miyakawa Hiroshi , Shultz Leonard D. , Ikehara Susumu , Gershwin M. Eric
Published: December 2003

Relatively little is known for the differentiation and maturation process of human B cells to plasma cells. This is particularly important in reconstitution work involving transfer of autoantibodies. To address this issue, we transplanted human peripheral blood mononuclear cells (PBMC) directly into the spleen of irradiated NOD/SCID mice depleted of natural killer cell activity. Within 6 weeks, naïve B cells differentiated into memory B cells and, importantly, the numbers of human CD138+ plasma cells in spleen increased by 100 fold after transplantation. Plasma cell numbers correlated with the detection of human IgM and IgG in serum, indicating that human B cells had differentiated into mature plasma cells in the murine spleen. In addition to CD19+ plasma cells, a distinct CD19- plasma cell population was detected, suggesting that downregulation of CD19 associated with maturation of plasma cells occurred. When purified human B cells were transplanted, those findings were not observed. Our results indicate that differentiation and maturation of human B cells and plasma cells can be investigated by transplantation of human PBMC into the spleen of NOD/SCID mice. The model will be useful for studying the differentiation of human B cells and generation of plasma cells.
Characterization of a Lipoyl Domain‐Independent B‐Cell Autoepitope on the Human Branched‐Chain Acyltransferase in Primary Biliary Cirrhosis and Overlap Syndrome with Autoimmune Hepatitis
Authors: Csepregi Antal , Obermayer-Straub Petra , Kneip Susanne , Kayser Anne , Loges Stephanie , Schmidt Eleonore , Nemesánszky Elemér , Szalay Ferenc , Manns Michael P. , Strassburg Christian P.
Published: December 2003

Background and aims: Antimitochondrial antibodies (AMA) which recognize pyruvate acetyltransferase (PDC‐E2) represent a highly diagnostic feature of primary biliary cirrhosis (PBC). The analysis of immunofluorescence (IF)‐AMA‐positive sera in PBC patients indicates a conformational epitope located within the lipoyl binding domain of bovine branched‐chain acyltransferase (BCKADC‐E2) alone or in combination with AMA directed against PDC‐E2 the significance of which is presently unclear. In the present study, immunoreactivities and disease associations of AMA against BCKADC‐E2 were analyzed. B‐cell autoepitopes on BCKADC‐E2 were mapped by immunoprecipitation assay.

Methods: Sera of 96 IF‐AMA‐positive patients with serological evidence of anti‐BCKADC‐E2 alone (n=26), anti‐PDC‐E2 alone (n=15), and both anti‐BCKADC‐E2 and anti‐PDC‐E2 (n=55) were analyzed by Western blot and ELISA in addition to an analysis of B cell autoepitopes on BCKADC‐E2 by immunoprecipitation using in vitro translated, unmodified human proteins. Ninety‐four patients without IF‐AMA [blood donors (n=30), rheumatoid arthritis (n=40), autoimmune hepatitis (AIH) (n=10) and primary sclerosing cholangitis (PSC) (n=14] served as controls.

Results: Eighty of 81 (99%) sera positive for BCKADC‐E2 recognized the full length, mature protein, while only 2/10 AIH sera and none of the other controls showed reactivity. Of the 68 PBC sera 58 (85%) recognized the N‐terminus consisting of aa 1‐144 representing the lipoyl domain. Surprisingly, C‐terminal sequences (aa 143‐421) were recognized by 46 out of 68 sera (68%). Three PBC sera reacted with the C‐terminus only. Only 1/7 serum from patients with an “overlap syndrome of PBC and AIH” was reactive with C‐terminal sequences.

Conclusions: Our analysis of BCKADC‐E2‐positive PBC sera identified a novel B cell epitope on the C‐terminal part of the human protein. Our data indicate that a distinct subset of AMA recognize sequence(s) on BCKADC‐E2 which located outside of the lipoyl binding domain. The absence of immunoreactivity against C‐terminal sequences may serve as a marker differentiating patients with PBC and overlap syndrome of PBC with AIH.
Magnitude of Alloresponses to MHC Class I/II Expressing Human Cardiac Myocytes is Limited by their Intrinsic Ability to Process and Present Antigenic Peptides
Authors: Sundstrom J. Bruce , Jollow Kimberley C. , Braud Veronique , Villinger Francois , McMichael Andrew J. , Lawrence E. Clinton , Ades Edwin W. , Ansari Aftab A.
Published: December 2003

In this investigation we have explored the relationship between the weak allogenicity of cardiac myocytes and their capacity to present allo‐antigens by examining the ability of a human cardiac myocyte cell line (W‐1) to process and present nominal antigens. W‐1 cells (HLA‐A*0201 and HLA‐DR β1*0301) pulsed with the influenza A matrix 1 (58‐66) peptide (M1) were able to serve as targets for the HLA‐A*0201 restricted CTL line PG, specific for M1‐peptide. However, PG‐CTLs were unable to lyse W‐1 target cells infected with a recombinant vaccinia virus expressing the M1 protein (M1‐VAC). Pretreatment of these M1‐VAC targets with IFN‐γ partially restored their ability to process and present the M1 peptide. However, parallel studies demonstrated that IFN‐γ pretreated W‐1′s could not process tetanus toxin (TT) or present the TT(830‐843) peptide to HLA‐DR3 restricted TT‐primed T cells. Semi‐quantitative RT‐PCR measurements revealed significantly lower constitutive levels of expression for MHC class I, TAP‐1/2, and LMP‐2/7 genes in W‐1s that could be elevated by pretreatment with IFN‐γ to values equal to or greater than those expressed in EBV‐PBLs. However, mRNA levels for the genes encoding MHC class II, Ii, CIITA, and DMA/B were markedly lower in both untreated and IFN‐γ pretreated W‐1s relative to EBV‐PBLs. Furthermore, pulse‐chase analysis of the corresponding genes revealed significantly lower protein levels and longer half‐life expression in W‐1s relative to EBV‐PBLs. These results suggest that weak allogenicity of cardiac myocytes may be governed by their limited expression of MHC genes and gene products critical for antigen processing and presentation.