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Xie S, Furjanic MA, Ferrara JJ, McAndrew NR, Ardino EL, Ngondara A, Bernstein Y, Thomas KJ, Kim E, Walker JM, Nagar S, Ward SJ, Raffa RB. The endocannabinoid system and rimonabant: a new drug with a novel mechanism of action involving cannabinoid CB1 receptor antagonism--or inverse agonism--as potential obesity treatment and other therapeutic use. J Clin Pharm Ther 2007; 32:209-31. [PMID: 17489873 DOI: 10.1111/j.1365-2710.2007.00817.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There is considerable evidence that the endocannabinoid (endogenous cannabinoid) system plays a significant role in appetitive drive and associated behaviours. It is therefore reasonable to hypothesize that the attenuation of the activity of this system would have therapeutic benefit in treating disorders that might have a component of excess appetitive drive or over-activity of the endocannabinoid system, such as obesity, ethanol and other drug abuse, and a variety of central nervous system and other disorders. Towards this end, antagonists of cannabinoid receptors have been designed through rational drug discovery efforts. Devoid of the abuse concerns that confound and impede the use of cannabinoid receptor agonists for legitimate medical purposes, investigation of the use of cannabinoid receptor antagonists as possible pharmacotherapeutic agents is currently being actively investigated. The compound furthest along this pathway is rimonabant, a selective CB(1) (cannabinoid receptor subtype 1) antagonist, or inverse agonist, approved in the European Union and under regulatory review in the United States for the treatment of obesity. This article summarizes the basic science of the endocannabinoid system and the therapeutic potential of cannabinoid receptor antagonists, with emphasis on the treatment of obesity.
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Vasilopoulos Y, Cork MJ, Teare D, Marinou I, Ward SJ, Duff GW, Tazi-Ahnini R. A nonsynonymous substitution of cystatin A, a cysteine protease inhibitor of house dust mite protease, leads to decreased mRNA stability and shows a significant association with atopic dermatitis. Allergy 2007; 62:514-9. [PMID: 17441792 DOI: 10.1111/j.1398-9995.2007.01350.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Cystatin A (CSTA) is a strong candidate for atopic dermatitis (AD) because it maps to AD susceptibility locus on chromosome 3q21 and it does inhibit Der p 1 and Der f 1, major house dust mite cysteine proteases and environmental triggers for AD and asthma. OBJECTIVE To examine any association between polymorphisms in CSTA and AD and study the effect on the CSTA mRNA expression level. METHODS We identified three polymorphisms and characterized the linkage disequilibrium mapping of the CSTA gene. All three CSTA polymorphisms were genotyped in 100 AD patients and 203 matched controls. Subsequently, we performed transfection-based RNA stability assays. RESULTS We found a significant association between the CSTA +344C variant and AD [odds ratio (OR) = 1.91; P = 0.024]. When further 61 control samples were genotyped. The association with CSTA +344C allele was enhanced OR = 2.13; P = 0.006. To test whether the CSTA +344 affected the CSTA transcriptional activity, the decay rates of RNAs transcribed from the CSTA +344C and CSTA +344T variants were investigated. COS-7 cells were transfected with a pcDNA3.1-CSTA+344C or a pcDNA3.1-CSTA+344T construct and cultured in the presence or absence of actinomycin D. Real-time RT-PCR revealed that CSTA +344C mRNA is more than two times less stable than the CSTA +344T mRNA (P < 0.001). CONCLUSION These results suggest that the CSTA +344C allele associated with unstable mRNA could result in failing to protect the skin barrier in AD patients from both exogenous and endogenous proteases.
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Ward SJ, Dykstra LA. The role of CB1 receptors in sweet versus fat reinforcement: effect of CB1 receptor deletion, CB1 receptor antagonism (SR141716A) and CB1 receptor agonism (CP-55940). Behav Pharmacol 2005; 16:381-8. [PMID: 16148442 DOI: 10.1097/00008877-200509000-00010] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
It is well established that Cannabis sativa can increase appetite, particularly for sweet and palatable foods. In laboratory animals, cannabinoid CB1 receptor antagonism decreases motivation for palatable foods, and most recently, the CB1 receptor antagonist SR141716A, or rimonabant (Acomplia), was reported to produce weight loss in obese human subjects. Indeed, the endocannabinoid system plays a select role in the rewarding properties of palatable foods, and this is well characterized in laboratory animals with sweet sucrose solutions. In the present study, CB1 knockout mice (CB1 KO) and wild-type littermate mice (WT) were trained to respond for a complex sweet as well as a pure fat reinforcer under a progressive ratio (PR) schedule, to determine whether motivation to consume different palatable foods is tonically regulated by CB1 receptors. To assess sweet reinforcement, several concentrations of the liquid nutritional drink, Ensure, were presented under the PR schedule. For fat reinforcement, several concentrations of corn oil (emulsified in 3% xanthan gum) were made available. Additionally, to compare the result of genetic invalidation of the CB1 receptor to antagonism of the CB1 receptor system, the effect of SR141716A (3.0 mg/kg) on responding for Ensure and corn oil were also assessed using the PR schedule. We also assessed the effect of the CB1 agonist CP-55940 (30 microg/kg) on responding for Ensure and corn oil. CB1 KOs took significantly longer to acquire operant responding maintained by Ensure, and responding for Ensure under the PR schedule was significantly reduced in CB1 KOs as well as in WTs pretreated with SR141716A, as compared to WT controls. Additionally, pretreatment with the CB1 agonist CP-55940 increased responding for Ensure. In contrast, responding for corn oil during acquisition and under the PR schedule was not significantly different in CB1 KOs versus wild-type mice. However, SR141716A did reduce responding for corn oil in WTs, and CP-55940 significantly increased responding for corn oil. Taken together, these results suggest that CB1 receptors are preferentially involved in the reinforcing effects of a complex sweet, as compared to a pure fat, reinforcer. These data also suggest, however, that antagonism of CB1 receptors with SR141716A is sufficient to attenuate the reinforcing effect of Ensure and corn oil, while activation of the central CB1 system is sufficient to enhance Ensure and corn oil reinforcement.
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MESH Headings
- Animals
- Conditioning, Operant/drug effects
- Corn Oil/administration & dosage
- Cyclohexanols/pharmacology
- Dietary Fats/administration & dosage
- Dietary Sucrose/administration & dosage
- Feeding Behavior/drug effects
- Feeding Behavior/physiology
- Female
- Food, Formulated
- Gene Deletion
- Genotype
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Piperidines/pharmacology
- Pyrazoles/pharmacology
- Receptor, Cannabinoid, CB1/drug effects
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/physiology
- Reinforcement, Psychology
- Rimonabant
- Taste/drug effects
- Taste/physiology
- Time Factors
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Banks SC, Lindenmayer DB, Ward SJ, Taylor AC. The effects of habitat fragmentation via forestry plantation establishment on spatial genotypic structure in the small marsupial carnivore, Antechinus agilis. Mol Ecol 2005; 14:1667-80. [PMID: 15836641 DOI: 10.1111/j.1365-294x.2005.02525.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dispersal is an important influence on species' distributions, patch colonization and population persistence in fragmented habitat. We studied the impacts of habitat fragmentation resulting from establishment of an exotic pine plantation on dispersal of the marsupial carnivore, Antechinus agilis. We applied spatial analyses of individual multilocus microsatellite genotypes and mitochondrial haplotypes to study patterns of gene flow in fragmented habitat and natural habitat 'control' areas, and how this is affected by the spatial dispersion of habitat patches, the presence of corridors and a 'mainland' source of migrants. Spatial analysis of molecular variance and partial Mantel tests confirmed the absence of cryptic barriers to gene flow in continuous habitat, which if present would confound the comparison of genetic structures in fragmented vs. unfragmented habitats. Spatial genotypic structure suggested that although dispersal was male-biased in both habitat types, fragmentation restricted dispersal of males more than that of females and the degree of restriction of male dispersal was dependent on the geographical isolation of the patch. The scale of positive genotypic structure in fragmented habitat was restricted to the two closest patches for females and the three closest patches for males. Our results provide evidence for significantly increased gene flow through habitat corridors relative to that across the matrix and for significantly lower gene flow between 'mainland' unfragmented habitat and habitat patches relative to that within either habitat type, suggesting a behavioural barrier to crossing habitat interfaces.
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Banks SC, Ward SJ, Lindenmayer DB, Finlayson GR, Lawson SJ, Taylor AC. The effects of habitat fragmentation on the social kin structure and mating system of the agile antechinus, Antechinus agilis. Mol Ecol 2005; 14:1789-801. [PMID: 15836650 DOI: 10.1111/j.1365-294x.2005.02535.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Habitat fragmentation is one of the major contributors to the loss of biodiversity worldwide. However, relatively little is known about its more immediate impacts on within-patch population processes such as social structure and mating systems, whose alteration may play an important role in extinction risk. We investigated the impacts of habitat fragmentation due to the establishment of an exotic softwood plantation on the social kin structure and breeding system of the Australian marsupial carnivore, Antechinus agilis. Restricted dispersal by males in fragmented habitat resulted in elevated relatedness among potential mates in populations in fragments, potentially increasing the risk of inbreeding. Antechinus agilis nests communally in tree hollows; these nests are important points for social contact between males and females in the mating season. In response to elevated relatedness among potential mates in fragmented habitat, A. agilis significantly avoided sharing nests with opposite-sex relatives in large fragment sites (but not in small ones, possibly due to limited nest locations and small population sizes). Because opposite-sex individuals shared nests randomly with respect to relatedness in unfragmented habitat, we interpreted the phenomenon in fragmented habitat as a precursor to inbreeding avoidance via mate choice. Despite evidence that female A. agilis at high inbreeding risk selected relatively unrelated mates, there was no overall increased avoidance of related mates by females in fragmented habitats compared to unfragmented habitats. Simulations indicated that only dispersal, and not nonrandom mating, contributed to inbreeding avoidance in either habitat context. However, habitat fragmentation did influence the mating system in that the degree of multiple paternity was reduced due to the reduction in population sizes and population connectivity. This, in turn, reduced the number of males available to females in the breeding season. This suggests that in addition to the obvious impacts of reduced recruitment, patch recolonization and increased genetic drift, the isolation of populations in habitat patches may cause changes in breeding behaviour that contribute to the negative impacts of habitat fragmentation.
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Vasilopoulos Y, Cork MJ, Murphy R, Williams HC, Robinson DA, Duff GW, Ward SJ, Tazi-Ahnini R. Genetic association between an AACC insertion in the 3'UTR of the stratum corneum chymotryptic enzyme gene and atopic dermatitis. J Invest Dermatol 2004; 123:62-6. [PMID: 15191543 DOI: 10.1111/j.0022-202x.2004.22708.x] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Atopic dermatitis is a disease with an impaired skin barrier that affects 15%-20% of children. In the normal epidermis, the stratum corneum chymotryptic enzyme (SCCE) thought to play a central role in desquamation by cleaving proteins of the stratum corneum (e.g., corneodesmosin and plakoglobin). Genetic variations within the SCCE gene could be associated with dysregulation of SCCE activity leading to an abnormal skin barrier. We screened the SCCE gene for variations and performed a case-control study on 103 atopic dermatitis patients and 261 matched controls. 16 synonymous single nucleotide polymorphisms (SNPs) have been identified and a 4 bp (AACC) insertion has been found in the 3'UTR. We performed an association study of the SCCE AACC insertion in the 3'UTR, and found a significant trend between the AACC allele with the two insertions and disease in the overall data set [odds ratio (OR)=2.31; p=0.0007]. The AACC insertion in the SCCE gene may result in a change to SCCE activity within the skin barrier. These findings suggest that SCCE could have an important role in the development of atopic dermatitis.
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Ward SJ, Morriss-Kay GM. The functional basis of tissue-specific retinoic acid signalling in embryos. Semin Cell Dev Biol 2004; 8:429-35. [PMID: 15001081 DOI: 10.1006/scdb.1997.0166] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Retinoic acid (RA) is essential for normal embryonic development. In mammals it is sequestered from the maternal circulation in the form of retinol. In rodents, embryonic uptake relies upon the presence of retinol binding protein (RBP) in the yolk sac, probably involving an RBP receptor. The molecular activity of RA in the nucleus is well established, but less is known about cytoplasmic events including tissue-specific intraembryonic RA synthesis and intracellular transport of both retinol and RA. The cellular binding proteins for retinol and RA may play important roles in these processes.
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Blinkhorn AS, Gratrix D, Holloway PJ, Wainwright-Stringer YM, Ward SJ, Worthington HV. A cluster randomised, controlled trial of the value of dental health educators in general dental practice. Br Dent J 2003; 195:395-400; discussion 385. [PMID: 14551632 DOI: 10.1038/sj.bdj.4810566] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2002] [Accepted: 02/28/2003] [Indexed: 11/09/2022]
Abstract
AIM To test the effectiveness of dental health educators in general dental practice. OBJECTIVE To evaluate the effectiveness and cost of primary care trusts seconding dental health educators free of charge to suitable general dental practices to provide dental health counselling to mothers of regularly attending pre-school children at risk to caries. METHOD Two-cell, parallel group, cluster randomised, controlled clinical trial of two years' duration. CLINICAL SETTING 30 general dental practices in North-West England. PARTICIPANTS 269 mothers of 334 pre-school children. INTERVENTIONS Those in the test group were given visits to a dental health educator over a 2-year period to counsel mothers of at-risk, pre-school children. The rest were held as a control. MAIN OUTCOME MEASURES Caries prevalence of the children and dental health knowledge, attitudes and toothbrushing skills of the parents. The full costs of the exercise were kept throughout. The statistical analysis controlled for the clustering of children within practices. RESULTS After 2 years, 271 (81%) children and 248 (92%) mothers remained in the study. There was an 18% difference in mean dmft between the groups in favour of the test group children but this was not statistically significant. At the end of the study there was an 18% difference in mean dmft between the groups in favour of the test group children but this was not statistically significant. No difference in plaque levels was found. The mothers in the test group were more knowledgeable, had better attitudes towards the dental health of their offspring and better toothbrushing skills than those in the control. Each 2-hour session to counsel ten parents cost pound 40. CONCLUSION Primary care trusts should carefully consider the cost value of seconding dental health educators to counsel parents of regularly attending, at-risk, pre-school children when considering such an option.
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Kraaijeveld-Smit FJL, Ward SJ, Temple-Smith PD. Paternity success and the direction of sexual selection in a field population of a semelparous marsupial, Antechinus agilis. Mol Ecol 2003; 12:475-84. [PMID: 12535097 DOI: 10.1046/j.1365-294x.2003.01745.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Antechinus agilis is a small sexually size dimorphic marsupial with a brief annual mating period of 2-3 weeks. All males die after this period, and females give birth to up to 10 young. Mating is thought to be promiscuous, however, there is no field data to confirm this. Using microsatellites, we investigated paternity patterns over two seasons in a wild population. Male weight was significantly positively related to the number of females fertilized and with the number of offspring sired, in both years. Furthermore, selection gradients indicated selection for larger males. Both results suggest that size dimorphism in A. agilis can be explained by sexual selection for larger males. The proportion of offspring sired within litters, did not relate to male size. Therefore, larger males are more successful through higher mating access, not through their sperm outcompeting that of smaller males. As expected from their known ranging behaviour, the number of offspring within litters left unassigned to a father did not depend on the grid location of the mother. Female size did not differ between successful reproducing and unsuccessful females. However, females that weaned offspring had larger heads than females that did not wean offspring. Males did not 'prefer' mating with larger females, nor did assortative mating occur. From our results, the mating system of A. agilis is clearly promiscuous. Selection for larger males occurred in both years, even though in one year the operational sex ratio was highly female biased, suggesting that the potential reproductive rate is a better predictor of the direction of sexual selection in A. agilis.
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Ward SJ. Training of Doctors project. MEDICAL EDUCATION 2002; 36:587-588. [PMID: 12047683 DOI: 10.1046/j.0308-0110.2002.01244.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Sapin V, Blanchon L, Serre AF, Lémery D, Dastugue B, Ward SJ. Use of transgenic mice model for understanding the placentation: towards clinical applications in human obstetrical pathologies? Transgenic Res 2001; 10:377-98. [PMID: 11708649 DOI: 10.1023/a:1012085713898] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The mammalian embryo and fetus are unable to develop without a well-established, functional placenta. This transitory yet indispensable structure attaches the conceptus to the uterus and establishes the vascular connections necessary for nutrient and gaseous exchange between maternal and fetal compartments. Genetic targeting strategy allows the generation of mice lacking a specific gene. Such approaches reveal: (i) the high incidence of mutant embryonic or fetal death in utero, and (ii) the extraembryonic (placental) causes of these deaths. Due to the similarities presented between mouse and human placenta, we propose to use the potential of mouse targeting experiments as a model in order to understand human obstetrical pathologies. In this paper, we first review genes that have been demonstrated to be required in mice for implantation, choriovitelline and chorioallantoic placentation. Using examples (integrins, homeoboxs, hepatocyte growth factor or epidermal growth factor receptor...) we demonstrate the reality and efficiency of such an approach. Other candidate genes (receptor of leukemia inhibitory factor, Wnt2 or retinoic acid receptor alpha...) in order to understand, prevent and treat human obstetrical pathologies.
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Tazi-Ahnini R, McDonagh AJ, Cox A, Messenger AG, Britton JE, Ward SJ, Båvik CO, Duff GW, Cork MJ. Association analysis of IL1A and IL1B variants in alopecia areata. Heredity (Edinb) 2001; 87:215-9. [PMID: 11703512 DOI: 10.1046/j.1365-2540.2001.00916.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Alopecia areata is an inflammatory hair loss disease with a major genetic component. The disease is characterized by focal inflammatory lesions with perifollicular T-cell infiltrates, reflecting the role of local cytokine production in the development of patchy hair loss. IL-1 alpha and IL-1 beta are important inhibitors of hair growth in vitro. Their effect is opposed by the interleukin-1 receptor antagonist, IL-1ra. Genes of the IL-1 cluster are candidate genes in the pathogenesis of alopecia areata. To investigate the role of the IL-1 system in alopecia areata we examined three biallelic polymorphisms within the IL-1 gene cluster (IL1A+4845, IL1B+3954 and IL1B-511) in 165 patients and a large number of matched controls (n=1150). There was no significant association of IL1B-511 or IL1B+3954 genotypes with the overall dataset, or with disease severity or age at onset, in contrast with a previous report. The results suggested the possibility of an association with IL1A+4845 in the overall dataset [OR 1.39 (95% CI 1.00, 1.93)] although this was not statistically significant. This was due mainly to the contribution from mild cases of alopecia areata [OR 1.48 (0.96, 2.29)], suggesting that IL-1 alpha may have a particular role in the pathogenesis of this subgroup.
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LeClair EE, Nguyen L, Bingle L, MacGowan A, Singleton V, Ward SJ, Bingle CD. Genomic organization of the mouse plunc gene and expression in the developing airways and thymus. Biochem Biophys Res Commun 2001; 284:792-7. [PMID: 11396972 DOI: 10.1006/bbrc.2001.5024] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Few genes have been isolated which display specific expression in the proximal airways. A recently identified mouse cDNA, plunc, appears to be confined to the upper airways and nasopharyngeal epithelium, and may prove a useful marker for these regions. We now report the genomic cloning and characterization of the mouse plunc gene as well as its developmental expression in the nasal and airway epithelium. We also report the novel finding that plunc is also expressed in the medullary compartment of the murine thymus. The mouse gene contains nine exons and the intron-exon boundaries are conserved with those in the human homologue. At e14.5 plunc is expressed in the nasal epithelium and several days later is seen in the thymic lobes, but not in the lining of the tracheobronchial tree. Expression in the trachea and main-stem bronchi first appears at 1--2 days after birth. Tracheobronchial expression persists at high levels throughout adulthood, as do regional areas of nasal and thymic expression. Finally, we show that the human homologue is expressed in bronchial epithelium, suggesting a transcript that is evolutionarily conserved in the mammalian airway.
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Sluiter AF, Close RL, Ward SJ. Koala feeding and roosting trees in the Campbelltown area of New South Wales. AUSTRALIAN MAMMALOGY 2001. [DOI: 10.1071/am01173] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
IN assessing habitat quality for koalas (Phascolarctos
cinereus), the relative importance of trees used for
food and for roosting must be established. Robbins
and Russell (1978) and Hindell et al. (1985)
suggested that trees in which P. cinereus roosted by
day reliably predicted the trees they browsed. Tun
(1993) and Hasegawa (1995), however, using leaf
cuticle analysis of P. cinereus faecal pellets,
questioned that suggestion .
Phillips and Callaghan (2000) investigated
preferences of P. cinereus in the Campbelltown area,
40 km southwest of Sydney, by recording the
presence of faecal pellets beneath trees in survey
quadrats. They concluded that Eucalyptus punctata
(grey gum) and E. agglomerata (blue-leaved stringy
bark) were preferred species on shale-based soils.
However, this method still does not distinguish
between trees used for roosting and those used for
feeding. Cuticle analysis was therefore used at
Campbelltown as a test of dietary preference (Table
1). These data on species use were compared with
sightings from a radio-tracking study of the same
individuals (Table 2), in a separate study (Ward
2002).
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Mollard R, Viville S, Ward SJ, Décimo D, Chambon P, Dollé P. Tissue-specific expression of retinoic acid receptor isoform transcripts in the mouse embryo. Mech Dev 2000; 94:223-32. [PMID: 10842077 DOI: 10.1016/s0925-4773(00)00303-8] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The three murine retinoic acid receptor (RAR) genes each contain two distinct promoters which give rise to protein isoforms differing in their N-terminal regions. This study used in situ hybridization to describe the expression patterns of RARalpha1, RARalpha2, RARbeta1/3, RARbeta2/4, RARgamma1 and RARgamma2 isoform transcripts during mouse embryogenesis. RARalpha1 transcripts are widely distributed, with the exception of the central nervous system. Highest expression is found in developing muscle, pituitary gland and various epithelia. On the other hand, RARalpha2 is essentially expressed along the spinal cord up to the hindbrain 7th rhombomere and in the 4th rhombomere, pons and developing basal ganglia (corpus striatum and pallidum). RARbeta2/4 transcripts account for most of the previously described RARbeta expression features being expressed specifically, or more prominently than RARbeta1/3, in foregut endoderm and its derivatives, olfactory and periocular mesenchyme, urogenital region, proximal limb bud mesenchyme and later within interdigital regions. RARbeta1/3 is more prominently expressed in the developing heart outflow tract mesenchyme, intervertebral disks, midgut loop mesenchyme and umbilical vessel walls. RARbeta1/3 and RARbeta2/4 are coexpressed in the developing corpus striatum. They exhibit, however, distinct dorsoventral distributions along the spinal cord and caudal hindbrain. RARgamma2 is the RARgamma isoform expressed at high levels in the caudal neural groove at embryonic day 8.5. At later stages, both RARgamma isoforms are essentially coexpressed, although the progressive restriction of RARgamma1 transcripts to craniofacial or limb precartilaginous condensations appears to precede that of RARgamma2.
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Foynes S, Dorrell N, Ward SJ, Stabler RA, McColm AA, Rycroft AN, Wren BW. Helicobacter pylori possesses two CheY response regulators and a histidine kinase sensor, CheA, which are essential for chemotaxis and colonization of the gastric mucosa. Infect Immun 2000; 68:2016-23. [PMID: 10722597 PMCID: PMC97381 DOI: 10.1128/iai.68.4.2016-2023.2000] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infection of the mucous layer of the human stomach by Helicobacter pylori requires the bacterium to be motile and presumably chemotactic. Previous studies have shown that fully functional flagella are essential for motility and colonization, but the role of chemotaxis remains unclear. The two-component regulatory system CheA/CheY has been shown to play a major role in chemotaxis in other enteric bacteria. Scrutiny of the 26695 genome sequence suggests that H. pylori has two CheY response regulators: one a separate protein (CheY1) and the other (CheY2) fused to the histidine kinase sensor CheA. Defined deletion mutations were introduced into cheY1, cheY2, and cheA in H. pylori strains N6 and SS1. Video tracking revealed that the wild-type H. pylori strain moves in short runs with frequent direction changes, in contrast to movement of cheY2, cheAY2, and cheAY2 cheY1 mutants, whose motion was more linear. The cheY1 mutant demonstrated a different motility phenotype of rapid tumbling. All mutants had impaired swarming and greatly reduced chemotactic responses to hog gastric mucin. Neither cheY1 nor cheAY2 mutants were able to colonize mice, but they generated a significant antibody response, suggesting that despite impaired chemotaxis, these mutants were able to survive in the stomach long enough to induce an immune response before being removed by gastric flow. Additionally, we demonstrated that cheY1 failed to colonize gnotobiotic piglets. This study demonstrates the importance of the roles of cheY1, cheY2, and cheA in motility and virulence of H. pylori.
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Dorrell N, Martino MC, Stabler RA, Ward SJ, Zhang ZW, McColm AA, Farthing MJ, Wren BW. Characterization of Helicobacter pylori PldA, a phospholipase with a role in colonization of the gastric mucosa. Gastroenterology 1999; 117:1098-104. [PMID: 10535872 DOI: 10.1016/s0016-5085(99)70394-x] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND & AIMS Phospholipase activity may play a role in the pathogenicity of Helicobacter pylori. Furthermore, some drugs that are effective against H. pylori infection are phospholipase inhibitors. Scrutiny of the H. pylori 26695 genome sequence revealed the presence of a putative protein with homology to Esherichia coli outer membrane phospholipase A (PldA). The aim of this study was to investigate the role of this putative PldA in the pathogenicity of H. pylori. METHODS An isogenic pldA mutant was constructed and analyzed for in vitro phospholipase A(2) and hemolytic activity. Adherence of the mutant to human gastric adenocarcinoma cells and the ability to colonize mice were also investigated. RESULTS The pldA mutant showed a marked reduction in phospholipase A(2) and hemolytic activity compared with the wild-type strain. The mutant was unable to colonize mice at 2 and 8 weeks, but it did induce a significant immune response. In contrast, the ability of the mutant to adhere to human gastric adenocarcinoma cells was unaffected. CONCLUSIONS The results suggest a role for PldA in colonization of the gastric mucosa and possibly tissue damage after colonization.
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Peters AR, Mawhinney I, Drew SB, Ward SJ, Warren MJ, Gordon PJ. Development of a gonadotrophin-releasing hormone and prostaglandin regimen for the planned breeding of dairy cows. Vet Rec 1999; 145:516-21. [PMID: 10576625 DOI: 10.1136/vr.145.18.516] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Four studies were carried out to determine the ovarian responses of dairy cows undergoing natural oestrous cycles to sequential injections of gonadotrophin-releasing hormone (GnRH), followed seven days later by prostaglandin and, 48 to 72 hours later, by a second injection of GnRH. In study 1, of 60 cows so treated, 47 were in the intended periovulatory phase when a fixed-time insemination was given 72 hours after the prostaglandin. In study 2, detailed observations were made in 32 cows treated as in study 1, using ultrasound to determine the optimum time to administer the second dose of GnRH. Ovulation was most effectively synchronised by giving GnRH 56 to 60 hours after the prostaglandin. Study 3 investigated the timing of ovulation when no initial dose of GnRH was given. Six cows were injected with prostaglandin on day 12 of the oestrous cycle, followed by GnRH 60 hours later. Five of the six cows ovulated 24 to 36 hours after GnRH, an equivalent timing and synchrony to that in study 2, in which a dose of GnRH had been given seven days before prostaglandin. In study 4, an initial dose of GnRH was given to six cows late (day 17) in the oestrous cycle, and prostaglandin seven days later. The GnRH treatment delayed luteolysis in five of the cows so that they were responsive to the prostaglandin and ovulated 24 to 36 hours after the second dose of GnRH. The use of GnRH (day 0) - prostaglandin (day 7) - GnRH (day 9.5) appears to be an effective means of synchronising ovulation in most cows.
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Ward SJ, Douce G, Dougan G, Wren BW. Local and systemic neutralizing antibody responses induced by intranasal immunization with the nontoxic binding domain of toxin A from Clostridium difficile. Infect Immun 1999; 67:5124-32. [PMID: 10496886 PMCID: PMC96861 DOI: 10.1128/iai.67.10.5124-5132.1999] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Fourteen of the 38 C-terminal repeats from Clostridium difficile toxin A (14CDTA) were cloned and expressed either with an N-terminal polyhistidine tag (14CDTA-HIS) or fused to the nontoxic binding domain from tetanus toxin (14CDTA-TETC). The recombinant proteins were successfully purified by bovine thyroglobulin affinity chromatography. Both C. difficile toxin A fusion proteins bound to known toxin A ligands present on the surface of rabbit erythrocytes. Intranasal immunization of BALB/c mice with three separate 10-microg doses of 14CDTA-HIS or -TETC generated significant levels of anti-toxin A serum antibodies compared to control animals. The coadministration of the mucosal adjuvant heat labile toxin (LT) from Escherichia coli (1 microg) significantly increased the anti-toxin A response in the serum and at the mucosal surface. Importantly, the local and systemic antibodies generated neutralized toxin A cytotoxicity. Impressive systemic and mucosal anti-toxin A responses were also seen following coadministration of 14CDTA-TETC with LTR72, an LT derivative with reduced toxicity which shows potential as a mucosal adjuvant for humans.
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Brown AK, Roddam AW, Spitz L, Ward SJ. Oesophageal atresia, related malformations, and medical problems: a family study. AMERICAN JOURNAL OF MEDICAL GENETICS 1999; 85:31-7. [PMID: 10377010 DOI: 10.1002/(sici)1096-8628(19990702)85:1<31::aid-ajmg7>3.0.co;2-d] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Oesophageal atresia (OA) and tracheo-oesophageal fistula (TOF) are life-threatening malformations of generally undefined cause. Previous reports of familial cases suggest a genetic contribution. The pattern of inheritance appears non-Mendelian, i.e., multifactorial. Individuals with OA/TOF often have other malformations and medical problems. The aim of this study was to determine the association in OA/TOF cases and healthy control subjects of associated malformations, midline defects, and medical conditions. We also investigate the relationships of these conditions in the relatives of the cases and controls. The results show that infants with OA/TOF frequently have VACTERL anomalies (vertebral, 17%; anal, 12%; cardiac, 20%; renal, 16%; limb, 10%) and other midline defects (cleft lip and palate, 2%; sacral dysgenesis, 2%; urogenital anomalies, 5%). The following medical problems were also reported: oesophageal dysmotility, 21%; gastro-oesophageal reflux, 22%; chest infections, 6%; and autonomic dysfunction, 0.5%. The first-degree relatives of children with OA are much more likely to have one of the aforementioned malformations or medical conditions when compared with the control group: one or more VACTERL anomalies (P < 0.01), gastro-oesophageal reflux (P < 0.05), recurrent respiratory infections (P < 0.05), and autonomic dysfunction (P < 0.001). The more distant relatives also show an increased incidence of such problems although in this case the data must be viewed with caution. The results confirm that the associated malformations and related medical problems occur significantly more frequently in the relatives of individuals with OA/TOF. These families may prove valuable for linkage analysis in an attempt to determine the genetics of OA/TOF.
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Abstract
This study was designed to examine the content and usefulness of departmental induction programmes to senior house officers (SHOs) and to explore perceptions of the usefulness of a range of topics to these trainees. A total of 64 SHOs, in five hospitals in the Anglia region, participated in semi-structured interviews up to 3 months after starting their post. The interviews investigated the content of any induction received and also examined what the trainees would have liked to have received. Almost half (29) of the SHOs also completed a questionnaire which examined the perceived usefulness of various induction topics for a trainee starting a new post. The results showed that, although a departmental induction programme is considered important and highly valued, a substantial minority of SHOs had not received one. Of this minority, 75% would have welcomed an induction. Where an induction had taken place, the focus was primarily upon timetables, tours and meeting people, however, a quarter of the questionnaire sample had not received a service timetable, a third had not met any consultants, two-thirds had received no introduction to clinical management, and two-thirds had received no information about how their consultants manage their patients. Thus, although many trainees receive an induction, important information may not be covered. A staged approach to departmental induction is recommended, using a short, high-quality, and comprehensive induction programme. Flexible and timely programmes, supported by comprehensive written information, will contribute to meeting the needs of trainees in an efficient and effective way.
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Abstract
The study was set up to examine how an induction programme can be designed to meet the needs and expectations of senior house officers (SHOs) beginning a new post in a hospital. A total of 63 SHOs, in five hospitals in the Anglia region, participated in standardised structured interviews up to 3 months after starting their post, by sorting a list of 38 possible induction topics in order of priority. Trainees' early induction needs were found to centre on day-one service activities, i.e., information that enables them to undertake their service work efficiently and effectively, is particularly valued and required early. Information related to clinical education and training is also valued, but many trainees prefer it to be provided after they have been in post for a week or two. Much induction information can also be effectively conveyed in writing, with little or no need for additional formal presentation. We conclude that first-day induction programmes which strive to satisfy the range of trainee needs in one session fail to take account of the different priorities that trainees attach to induction information. Trainees do not want all information at once. Information of prime concern to clinical tutors, namely education, training and generic skills, is generally favoured after a week or two. To ensure that trainees' hospital induction needs are met in an efficient and effective way, programmes must be flexible and timely, and supported by comprehensive written information.
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