90,065 results

  • Multi-gene analysis of Symbiodinium dinoflagellates: A perspective on rarity, symbiosis, and evolution

    Pochon, Xavier; Putnam, HM; Gates, RD (2014)

    Journal article
    The University of Auckland Library

    Symbiodinium, a large group of dinoflagellates, live in symbiosis with marine protists, invertebrate metazoans, and free-living in the environment. Symbiodinium are functionally variable and play critical energetic roles in symbiosis. Our knowledge of Symbiodinium has been historically constrained by the limited number of molecular markers available to study evolution in the genus. Here we compare six functional genes, representing three cellular compartments, in the nine known Symbiodinium lineages. Despite striking similarities among the single gene phylogenies from distinct organelles, none were evolutionarily identical. A fully concatenated reconstruction, however, yielded a well-resolved topology identical to the current benchmark nr28S gene. Evolutionary rates differed among cellular compartments and clades, a pattern largely driven by higher rates of evolution in the chloroplast genes of Symbiodinium clades D2 and I. The rapid rates of evolution observed amongst these relatively uncommon Symbiodinium lineages in the functionally critical chloroplast may translate into potential innovation for the symbiosis. The multi-gene analysis highlights the potential power of assessing genome-wide evolutionary patterns using recent advances in sequencing technology and emphasizes the importance of integrating ecological data with more comprehensive sampling of free-living and symbiotic Symbiodinium in assessing the evolutionary adaptation of this enigmatic dinoflagellate.

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  • Paget disease of bone

    Cundy, Timothy; Bolland, Mark (2008)

    Journal article
    The University of Auckland Library

    Despite significant advances in management, Paget disease remains an enigmatic disorder. There are no animal models, and while its end result ??? a focal disorder of accelerated bone turnover ??? is easily recognized, the causes and evolution of the disorder remain uncertain. Recent evidence strongly implicates both genetic and environmental factors in its etiology. The authors consider some of the unresolved questions surrounding Paget disease, including the attenuating prevalence and severity of the disease; how these observations might be reconciled with an apparently highly penetrant genetic susceptibility; what the putative environmental triggers of Paget disease might be; and what relapse after treatment tells us. Most observations seem to fit best with the idea that Paget disease behaves as a multifocal benign neoplasm.

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  • Association of the lipoprotein receptor-related protein 2 gene with gout and non-additive interaction with alcohol consumption.

    Rasheed, H; Phipps-Green, A; Topless, R; Hollis-Moffatt, JE; Hindmarsh, JH; Franklin, C; Dalbeth, Nicola; Jones, Peter; White, Douglas; Stamp, LK; Merriman, TR (2013)

    Journal article
    The University of Auckland Library

    Introduction: The T allele of a single nucleotide polymorphism (SNP: rs2544390) in lipoprotein receptor-related protein 2 (LRP2) is associated with higher serum urate and risk of gout in Japanese individuals. SNP rs2544390 also interacts with alcohol consumption in determining hyperuricemia in this population. We investigated the association of rs2544390 with gout, and interaction with all types of alcohol consumption in European and New Zealand (NZ) M??ori and Pacific subjects, and a M??ori study cohort from the East Coast region of NZ's North Island. Methods: Rs2544390 was genotyped by Taqman??. From NZ a total of 1205 controls and 1431 gout cases clinically ascertained were used. Publicly available genotype and serum urate data were utilized from the Atherosclerosis Risk in Communities (ARIC) study and the Framingham Heart Study (FHS). Alcohol consumption data were obtained by consumption frequency questions in all study cohorts. Multivariate adjusted logistic regression was done using STATA. Results: The T allele of rs2544390 was associated with increased risk of gout in the combined M??ori and Pacific Island cohort (OR???=???1.20, P???=???0.009), and associated with gout in the European subjects, but with a protective effect (OR???=???0.79, PUnadjusted???=???0.02). Alcohol consumption was positively associated with risk of gout in M??ori and Pacific subjects (0.2% increased risk/g/week, P???=???0.004). There was a non-additive interaction between any alcohol intake and the risk of gout in the combined M??ori and Pacific cohorts (PInteraction???=???0.001), where any alcohol intake was associated with a 4.18-fold increased risk in the CC genotype group (P???=???6.6x10-5), compared with a 1.14-fold increased risk in the CT/TT genotype group (P???=???0.40). These effects were not observed in European subjects. Conclusions: Association of the T-allele with gout risk in the M??ori and Pacific subjects was consistent with this allele increasing serum urate in Japanese individuals. The non-additive interaction in the M??ori and Pacific subjects showed that alcohol consumption over-rides any protective effect conferred by the CC genotype. Further exploration of the mechanism underlying this interaction should generate new understanding of the biological role of alcohol in gout, in addition to strengthening the evidence base for reduction of alcohol consumption in the management of gout.

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  • Paget's disease of bone - becoming a rarity?

    Bastin, S; Bird, H; Gamble, Gregory; Cundy, Timothy (2009)

    Journal article
    The University of Auckland Library

    Objectives. Paget's disease is a chronic bone disorder of unknown cause. Recent studies have reported an unexplained reduction in both prevalence and disease severity. We undertook a radiographic survey to determine the current prevalence of Paget's disease in New Zealand (previously recognized as a high prevalence area). Methods. A total of 3350 plain abdominal radiographs taken in 2005???06 in subjects of European descent >54 years old were examined for Paget's disease. The results were compared with those of a similar survey from 1996???98. The medical record of affected subjects was examined to determine when the disease had been first recognized and the plasma ALP at that time. Results. Paget's disease was detected in 87 radiographs (2.6%). In 55 cases (63%), it was already known to have been present, for a mean 14 years beforehand. The newly recognized or ???incident??? cases were significantly older (mean age 86 vs 67 years, P < 0.0001) and had milder disease (ALP 139 vs 239 u/l, P < 0.0001) than the known cases. Compared with the 1996???98 survey, the age distribution of affected patients was shifted to the right, with a significantly lower proportion in the youngest age group (55???69 years, P < 0.004). Conclusions. These results confirm the secular trend of Paget's disease presenting later in life and in milder form, suggesting that there are important environmental determinants. The relatively few ???incident??? cases are mostly in the very elderly. Given the secular trend and limitations to life expectancy, it is predicted that Paget's disease will become increasingly rare.

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  • The case for improving road safety in Pacific Islands: a population-based study from Fiji (TRIP 6)

    Herman, Josephine; Ameratunga, Shanthi; Wainiqolo, I; Kafoa, B; McCaig, E; Jackson, Rodney (2012-10)

    Journal article
    The University of Auckland Library

    OBJECTIVE: To estimate the incidence and demographic characteristics associated with road traffic injuries (RTIs) resulting in deaths or hospital admission for 12 hours or more in Viti Levu, Fiji. METHODS: Analysis of the prospective population-based Fiji Injury Surveillance in Hospitals database (October 2005 - September 2006). RESULTS: Of the 374 RTI cases identified (17% of all injuries), 72% were males and one third were aged 15-29 years. RTI fatalities (10.3 per 100,000 per year) were higher among Indians compared to Fijians. Two-thirds of deaths (largely ascribed to head, chest and abdominal trauma) occurred before hospital admission. CONCLUSION AND IMPLICATIONS: While the RTI fatality rate was comparable to the global average for high-income countries, the level of motorisation in Fiji is considerably lower. To avert rising RTI rates with increasing motorisation, Fiji requires a robust road safety strategy alongside effective trauma-care services and a reliable population-based RTI surveillance system.

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  • Absence of somatic SQSTM1 mutations in Paget's disease of bone

    Matthews, Brya; Naot, Dorit; Bava, U; Callon, KE; Pitto, Rocco; McCowan, SA; Wattie, D; Cundy, Timothy; Cornish, Jillian; Reid, Ian (2009)

    Journal article
    The University of Auckland Library

    Background: Paget???s disease is a common focal bone disorder that appears to be caused by a combination of genetic and environmental factors. Mutations in the SQSTM1 gene are found in about one third of families with Paget???s disease and 8% of sporadic cases. Other potential loci linked to the disease have also been identified, and a number of environmental factors have been suggested to be involved in the disease. However, the focal nature of Paget???s is still unexplained. Therefore, we examined the possibility that somatic mutations in the SQSTM1 gene are present in the local lesions, using RNA collected from primary osteoblast and bone marrow cell cultures of patients with this condition. Methods: SQSTM1 was sequenced, and allelic discrimination for the common P392L mutation was performed in cDNA samples from 14 osteoblast cultures and from 14 cultures of bone marrow cells. Results: In these 28 samples drawn from 23 patients, the wild-type sequence of SQSTM1 was found in all but one marrow sample, which was heterozygous for the P392L mutation. DNA from peripheral blood in this subject had an identical sequence of SQSTM1, indicating that this was a germline mutation. Conclusion: We conclude that somatic mutations for SQSTM1 are not commonly present in Paget???s disease.

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  • Comparative responses of bone turnover markers to bisphosphonate therapy in Paget's disease of bone

    Reid, Ian; Davidson, JS; Wattie, D; Wu, F; Lucas, J; Gamble, GD; Rutland, MD; Cundy, Timothy (2004)

    Journal article
    The University of Auckland Library

    The measurement of biochemical markers of bone turnover is integral to the diagnosis and management of Paget's disease. Recently, there has been a proliferation of new markers and a move to carry out existing assays on automated platforms. We have assessed the performance of seven currently available markers in 20 patients with Paget's disease undergoing ibandronate therapy (6 or 12 mg) and in nine placebo-treated controls. Samples were collected at baseline and 6 months following intervention. The mean reductions in serum markers following treatment with either dose of ibandronate were: total alkaline phosphatase (AP; Roche Modular) 70%, bone AP (Beckman Access, Ostase) 80%, osteocalcin (Roche Elecsys 2010) 33%, ??-C-terminal telopeptide of type I collagen (??CTX; Roche Elecsys 2010) 50%, and procollagen-N-terminal peptide (P1NP; Roche Elecsys 2010) 80%. For urine markers the reductions were: free deoxypyridinoline/creatinine (fDPD/creat) (DPC Immulite 2000) 36%, and N-telopeptide/creatinine (NTX/creat) (Osteomark) 81%. Total AP, bone AP, P1NP, and NTX all showed >95% of subjects to have abnormal values at baseline, reducing to 15???30% following treatment, and these treatment effects were highly significant (P ??? 0.0005), except for NTX (P = 0.02). The poorer precision of NTX reduced its utility. Baseline sensitivity was lower for the other markers (osteocalcin 68% of subjects abnormal, fDPD 22%, ??CTX 50%). Total AP, bone AP, and P1NP are suitable osteoblast markers for monitoring bisphosphonate therapy in Paget's disease, with performance approaching that of bone scintigraphy. NTX is less sensitive in detecting the effects of therapy, but is the best performing bone resorption marker. There is no clear evidence from this study that any of these newer markers are superior to total AP in assessing patients with this severity of Paget's disease.

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  • Extra-aortic balloon counterpulsation: an intra-operative feasibility study.

    Legget, Malcolm; Peters, WS; Milson, FP; Clark, J; West, TM; French, RL; Merry, Alan (2005)

    Journal article
    The University of Auckland Library

    Background??? Current methods of counterpulsation or ventricular assistance have significant vascular and limb complications. The aim of this study was to determine the safety and performance of a new method of non-blood???contacting counterpulsation using an inflatable cuff around the ascending aorta (extra-aortic balloon [EAB]). Methods and Results??? In 6 patients undergoing first time off-pump coronary bypass surgery via sternotomy, the EAB was secured around the ascending aorta and attached to a standard counterpulsation console. At baseline and with 1:2 and 1:1 augmentation, hemodynamic and echocardiographic parameters of ventricular function and coronary flow were measured. High-intensity transient signals were measured using transcutaneous Doppler over the right common carotid artery. No complications occurred. With EAB there was no significant change in heart rate or blood pressure and no increase in high-intensity transient signals. There was a 67% increase in diastolic coronary blood flow (mean left-main diastolic velocity time integral 15.3 cm unassisted versus 25.1 cm assisted, P<0.005). Conclusions??? EAB counterpulsation augments coronary flow and reduces left ventricular afterload. Further testing is warranted to assess the use of the EAB for chronic non-blood???contacting support of the failing heart.

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  • The effectiveness, acceptability and costs of a hospital-at-home service compared with acute hospital care: a randomized controlled trial

    Harris, Roger; Ashton, Toni; Broad, Joanna; Connelly, G; Richmond, D (2005-07-01)

    Journal article
    The University of Auckland Library

    Objective: To compare the safety, effectiveness, acceptability and costs of a hospital-at-home programme with usual acute hospital inpatient care.

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  • Safety in Anaesthesia

    Merry, Alan (2009)

    Journal article
    The University of Auckland Library

    latrogenic harm is a major problem in healthcare, and incident reporting is one of various methods of identifying areas for improvement in patient safety. The World Health Organisation has introduced a three-phase checklist to reduce error and improve teamwork and communication during surgery. Use of this checklist has been shown to reduce harm. Incident reporting will be invaluable in monitoring its effectiveness and identifying areas for refinement.

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  • Scout's motto

    Baker, Paul; Merry, Alan (2009)

    Journal article
    The University of Auckland Library

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  • Early sex and its behavioral consequences in New Zealand

    Davis, Peter; Lay Yee, Roy (1999)

    Journal article
    The University of Auckland Library

    A steady trend towards earlier sexual intercourse is now well documented. However; the relationship of this development to trends in other early sexual formative experiences has not been explored, nor has there been an analysis of the longer-term behavioral consequences. The data examined in this paper were drawn from a two-stage national survey of sexual lifestyles on a sample of 2,361 adult New Zealanders in the age range 18-54. Techniques of survival analysis and multiple logistic regression were used Over time there was a consistent decline and diminishing gap in age of onset for first experience, first intercourse, and first regular partnership. Multivariate analysis confirms that males, the young, the less educated ethnic minorities, and respondents professing no religious affiliation were all more likely to report earlier onset of sexual experiences. However; while all three socio-sexual events showed the same trend pre-intercourse experiences exerted the strongest influence on subsequent sexual practices and outcomes. This has implications for preventive strategies.

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  • Population structure in the barn swallow, Hirundo rustica: a comparison between neutral DNA markers and quantitative traits

    Santure, Anna; Ewen, JG; Sicard, D; Roff, DA; Moller, AP (2010-02)

    Journal article
    The University of Auckland Library

    Local adaptation to variable environments can generate clinal variation in morphological traits. Alternatively, similar patterns of clinal variation may be generated simply as a result of genetic drift/migration balance. Teasing apart these different processes is a continuing focus in evolutionary ecology. We compare genetic differentiation at molecular loci and quantitative traits to analyse the effect of these different processes in a morphological latitudinal cline of the barn swallow, Hirundo rustica, breeding across Europe. The results obtained show no structuring at neutral microsatellite loci, which contrasts with positive structuring at five quantitative morphometric traits. This supports the hypothesis that the observed morphometric cline in barn swallows is the result of selection acting in a spatially heterogeneous environment.

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  • Influence of mom and dad: Quantitative genetic models for maternal effects and genomic imprinting

    Santure, Anna; Spencer, HG (2006-08)

    Journal article
    The University of Auckland Library

    The expression of an imprinted gene is dependent on the sex of the parent it was inherited from, and as a result reciprocal heterozygotes may display different phenotypes. In contrast, maternal genetic terms arise when the phenotype of an offspring is influenced by the phenotype of its mother beyond the direct inheritance of alleles. Both maternal effects and imprinting may contribute to resemblance between offspring of the same mother. We demonstrate that two standard quantitative genetic models for deriving breeding values, population variances and covariances between relatives, are not equivalent when maternal genetic effects and imprinting are acting. Maternal and imprinting effects introduce both sex-dependent and generation-dependent effects that result in differences in the way additive and dominance effects are defined for the two approaches. We use a simple example to demonstrate that both imprinting and maternal genetic effects add extra terms to covariances between relatives and that model misspecification may over- or underestimate true covariances or lead to extremely variable parameter estimation. Thus, an understanding of various forms of parental effects is essential in correctly estimating quantitative genetic variance components.

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  • Drowning terminology: Not what it used to be

    Jones, Peter; Moran, Kevin; Webber, Jonathon (2013)

    Journal article
    The University of Auckland Library

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  • Association of innate immune single-nucleotide polymorphisms with the electroencephalogram during desflurane general anaesthesia

    Mulholland, CV; Somogyi, AA; Barratt, DT; Coller, JK; Hutchinson, MR; Jacobson, GM; Cursons, RT; Sleigh, James (2014-04)

    Journal article
    The University of Auckland Library

    The electroencephalogram (EEG) records the electrical activity of the brain and enables effects of anaesthetic drugs on brain functioning to be monitored. Identification of genes contributing to EEG variability during anaesthesia is important to the clinical application of anaesthesia monitoring and may provide an avenue to identify molecular mechanisms underlying the generation and regulation of brain oscillations. Central immune signalling can impact neuronal activity in the brain and accumulating evidence suggests an important role for cytokines as neuronal modulators. We tested 21 single-nucleotide polymorphisms (SNPs) in immune-related genes for associations with three anaesthesia-induced EEG patterns; spindle amplitude, delta power and alpha power, during general anaesthesia with desflurane in 111 patients undergoing general, gynaecological or orthopaedic surgery. Wide inter-patient variability was observed for all EEG variables. MYD88 rs6853 (p=6.7x10-4) and IL-1?? rs1143627 in conjunction with rs6853 (p=1.5x10-3) were associated with spindle amplitude, and IL-10 rs1800896 was associated with delta power (p=1.3x10 -2) suggesting involvement of cytokine signalling in modulation of EEG patterns during desflurane anaesthesia. BDNF rs6265 was associated with alpha power (p=3.9x10-3), suggesting differences in neuronal plasticity might also influence EEG patterns during desflurane anaesthesia. This is the first study we are aware of that has investigated genetic polymorphisms that may influence the EEG during general anaesthesia.

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  • Corticomotor excitability and plasticity following complex visuomotor training in young and old adults

    Cirillo, John; Todd, G; Semmler, JG (2011-12)

    Journal article
    The University of Auckland Library

    Previous studies with transcranial magnetic stimulation (TMS) have shown that advancing age may influence plasticity induction in human motor cortex (M1), but these changes have been assessed with TMS-induced paradigms or simple motor tasks. The aim of this study was to examine changes in corticospinal excitability and intracortical inhibition as markers of corticomotor plasticity following complex motor training in young and old adults. Electromyographic recordings were obtained from the right first dorsal interosseous (FDI) muscle of 16 young (20???35 years) and 16 older (aged 60???75 years) adults before and after motor skill training. Motor training consisted of three 6-minute blocks of a complex visuomotor task that required matching the metacarpophalangeal (MCP) joint angle of the index finger using abduction???adduction movements. Single- and paired-pulse TMS over the left M1 was used to assess changes in right FDI motor-evoked potentials (MEPs) and short-interval intracortical inhibition (SICI) before and after each training block. Visuomotor tracking performance was diminished in old compared with young adults throughout training. However, improvement in tracking error was similar for young and old adults (7???24% increase in each training block). For young and old adults, motor training increased FDI MEP amplitude (??? 20%) and reduced the magnitude of SICI (??? 19%) after each visuomotor training block, reflecting use-dependent plasticity. However, no difference in corticomotor plasticity (change in MEP or SICI) was observed between young and old adults. Further studies are needed to identify the experimental or behavioral factors that might contribute to the maintenance of corticomotor plasticity in older adults.

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  • Differential modulation of motor cortex excitability in BDNF Met allele carriers following experimentally induced and use-dependent plasticity

    Cirillo, John; Hughes, J; Ridding, M; Thomas, PQ; Semmler, JG (2012-09)

    Journal article
    The University of Auckland Library

    The purpose of this study was to investigate how healthy young subjects with one of three variants of the brain-derived neurotrophic factor (BDNF) gene modulate motor cortex excitability following experimentally induced and use-dependent plasticity interventions. Electromyographic recordings were obtained from the right first dorsal interosseous (FDI) muscle of 12 Val/Val, ten Val/Met and seven Met/Met genotypes (aged 18???39 years). Transcranial magnetic stimulation of the left hemisphere was used to assess changes in FDI motor-evoked potentials (MEPs) following three separate interventions involving paired associative stimulation, a simple ballistic task and complex visuomotor tracking task using the index finger. Val/Val subjects increased FDI MEPs following all interventions (??? 25%, P < 0.01), whereas the Met allele carriers only showed increased MEPs after the simple motor task (??? 26%, P < 0.01). In contrast to the simple motor task, there was no significant change in MEPs for the Val/Met subjects (7%, P = 0.50) and a reduction in MEPs for the Met/Met group (???38%, P < 0.01) following the complex motor task. Despite these differences in use-dependent plasticity, the performance of both motor tasks was not different between BDNF genotypes. We conclude that modulation of motor cortex excitability is strongly influenced by the BDNF polymorphism, with the greatest differences observed for the complex motor task. We also found unique motor cortex plasticity in the rarest form of the BDNF polymorphism (Met/Met subjects), which may have implications for functional recovery after disease or injury to the nervous system in these individuals.

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  • Hemispheric differences in use-dependent corticomotor plasticity in young and old adults

    Cirillo, John; Rogasch, NC; Semmler, JG (2010-08)

    Journal article
    The University of Auckland Library

    The aim of this study was to examine corticomotor excitability and plasticity following repetitive thumb abduction training in left and right hands of young and old adults. Electromyographic recordings were obtained from the abductor pollicis brevis (APB) muscle of 12 young (aged 18???27 years) and 14 old (aged 63???75 years) adults. Motor training consisted of 300 ballistic abductions of the thumb to maximize peak abduction acceleration, with each hand tested in a separate session. Transcranial magnetic stimulation (TMS) over the primary motor cortex (M1) was used to assess changes in contralateral APB motor-evoked potentials (MEPs) and short-interval intracortical inhibition (SICI) before and after training. For young and old adults, APB MEP amplitude increased for both hands after training, which is indicative of use-dependent plasticity. However, the increase in MEP amplitude was 21% (P = 0.04) greater in the left (non-dominant) hand compared with the right (dominant) hand. This occurred despite a 40% greater improvement in peak thumb abduction acceleration (motor learning) for the right hand in young subjects compared with the left hand in young subjects (P < 0.04) and the right hand in old subjects (P < 0.01). Furthermore, no difference in use-dependent plasticity was observed between young and old adults, and SICI remained unchanged following ballistic training for both hands in all subjects. These findings suggest that there is greater strengthening of corticomotor circuits for control of the left compared with the right hand during simple ballistic thumb training and that an age-related decline in motor learning was observed only in the dominant hand. In contrast to previous studies, these data also indicate that young and old adults can demonstrate similar use-dependent corticomotor plasticity during this simple thumb-training task.

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  • Metal-derivatized major histocompatibility complex: Zeroing in on contact hypersensitivity

    Hughes, Jacelyn; Fraser, John (2003-03-03)

    Journal article
    The University of Auckland Library

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