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S Turner

Publications and source records attributed to S Turner.

At least 55 records · Page 3Linked to original sources
PubMed2001

Sequence-based typing of HLA class I alleles in Alaskan Yupik Eskimo.

In comparison to South America, native North Americans tend to be less diverse in their repertoire of HLA class I alleles. Based upon this observation, we hypothesized that the Yupik Eskimo would exhibit a limited number of previously identified class I HLA alleles. To test this hypothesis, sequence-based typing was performed at the HLA-A, -B and -C loci for 99 Central Yupik individuals from southwestern Alaska. Two new class I alleles, A*2423 and Cw*0806, were identified. While A*2423 was observed in only one sample, Cw*0806 was present in 26 of the 99 individuals and all of the Cw*0806 samples contained B*4801. Allele Cw*0806 differs from Cw*0803 by a single nucleotide substitution such that Cw*0803 may be the progenitor of Cw*0806. Allele Cw*0803 was originally characterized as unique to South America, but detection of Cw*0803 in the Yupik indicates that Cw*0803 was a founding allele of the Americas. The presence of new alleles and previously unrecognized founding alleles in the Yupik population show that natives of North America are more diverse than previously envisioned.

Alaska↗
PubMed2001

A brief report on the Penn Inventory for posttraumatic stress disorder.

In this report we provide normative data for the Penn Inventory for posttraumatic stress disorder for men and women who were referred to a specialist outpatient clinic following a range of traumatic events. Data are provided from clinical assessment of 80 people. There was no significant difference between male and female scores. Using the Clinician Administered PTSD Scale to ascertain diagnostic status and Hammarberg's cut-off criterion of 35, the Penn Inventory showed a sensitivity of .90 for male participants and .89 for female participants and a specificity of .55 for male participants and .67 for female participants. The Penn Inventory correlated highly with other measures of psychological distress. We discuss that the Penn Inventory may be best used as a screening instrument or measure of change of general mental well-being after trauma, rather than a diagnostic tool for specific traumatic stress symptoms.

Adult↗
PubMed2001

Non-conservative substitutions distinguish previously uncharacterized HLA-A molecules.

The extent of class I HLA polymorphism is not yet realized, and to provide a glimpse of the HLA-A polymorphism which remains undetected, we have analyzed approximately 3,700 National Marrow Donor Program (NMDP) Donor/Recipient Pair Retrospective Study Samples with HLA-A DNA sequence-based typing (SBT). Seventeen new HLA-A alleles were detected, with a total of 19 nucleotide substitutions distinguishing these new alleles from their closest HLA-A relatives. Nearly all of the new alleles differ by single nucleotide substitutions; a majority of these substitutions can be explained by gene conversion events but 6 alleles likely originated by point mutation. Fifteen of the 19 nucleotide substitutions translate into amino acid differences in the molecule. Structurally, the inferred amino acid alterations were non-conservative in terms of chemical property, and most substitutions were positioned in 1 or more of the specificity pockets which determine peptide binding. Although these new alleles were identified in a primarily Caucasian sample population, 9 of the 17 new HLA-A alleles were found in samples of non-Caucasoid origin. A new allele detection rate of 1 in approximately 200 individuals in our data set would, therefore, be higher in a non-Caucasoid sample population. In summary, the single nucleotide substitutions that distinguish undetected HLA-A alleles translate into functionally distinct HLA-A molecules. Further studies of the role of HLA-A in transplantation, in disease association, and in evolution must therefore accommodate the discovery of new alleles differing by single nucleotides.

Alleles↗
PubMed2001

BOTERO1 is required for normal orientation of cortical microtubules and anisotropic cell expansion in Arabidopsis.

Mutants at the BOTERO1 locus are affected in anisotropic growth in all non-tip-growing cell types examined. Mutant cells are shorter and broader than those of the wild type. Mutant inflorescence stems show a dramatically reduced bending modulus and maximum stress at yield. Our observations of root epidermis cells show that the cell expansion defect in bot1 is correlated with a defect in the orientation of the cortical microtubules. We found that in cells within the apical portion of the root, which roughly corresponds to the meristem, microtubules were loosely organized and became much more highly aligned in transverse arrays with increasing distance from the tip. Such a transition was not observed in bot1. No defect in microtubule organization was observed in kor-1, another mutant with a radial cell expansion defect. We also found that in wild-type root epidermal cells, cessation of radial expansion precedes the increased alignment of cortical microtubules into transverse arrays. Bot1 roots still show a gravitropic response, which indicates that ordered cortical microtubules are not required for differential growth during gravitropism. Interestingly, the fact that in the mutant, these major changes in microtubule organization cause relatively subtle changes in cell morphology, suggest that other levels of control of growth anisotropy remain to be discovered. Together, these observations suggest that BOT1 is required for organizing cortical microtubules into transverse arrays in interphase cells, and that this organization is required for consolidating, rather than initiating, changes in the direction of cell expansion.

Arabidopsis↗
PubMed2001

Estimating occupational health events in workers with asthma or diabetes: a comparison of diary and snapshot methods.

The study was set up to assess the completeness of reporting different types of work-related health events through 6 month and 1 week diaries and telephone questionnaires relating to individual days. Subjects recruited from hospital asthma or diabetic clinics or from surgical day-case units were randomly assigned to either a full participation arm or to one completing only a 6 month diary. Of the 375 study participants, return rates were 68.8% for 6 month diaries, 81.9% for weekly diaries and 86.5% for researcher-administered questionnaires. Significantly higher rates of self-reported poor work performance, symptoms or changes in medication were estimated by snapshot methods (same-day telephone interviews or one-off weekly diaries) than from diaries completed over a 6 month period. Asthmatics and diabetics attending hospital outpatient clinics were no more likely, however, to report work-related health events in the following 6 months than those attending the same hospital for day surgery.

Adolescent↗
PubMed2001

Detection of Plasmodium falciparum DNA in plasma.

We present a new application in the field of circulating nucleic acids in plasma: the detection of parasite DNA in plasma. We have investigated the presence of Plasmodium falciparum (P. falciparum) DNA in the blood cells and plasma of patients with malaria. Ten blood samples from malaria patients and 9 blood samples from healthy volunteers were collected. Plasma was separated and DNA was extracted from both plasma and blood cells. DNA samples were subjected to a nested polymerase chain reaction (PCR) for the small subunit rRNA gene of P. falciparum and a control amplification of the human rRNA gene. All 6 cases positive by microscopy for P. falciparum were positive by PCR on DNA extracted from blood cells and plasma. Two cases negative by microscopy for malaria were positive by PCR--the blood samples were taken from one of the cases at 7 days after successful treatment of malaria and the other case at the onset of the malaria illness. Two other cases were negative by microscopy and by PCR on blood cells and plasma, both after successful treatment of malaria. The quantitation of Plasmodium DNA in plasma may prove to be a useful prognostic measurement in malaria, and the detection of P. falciparum DNA in archival stored plasma samples may allow the reconstruction of the recent historic evolution of the parasite genome.

Animals↗
PubMed2001

The role of shame and guilt in traumatic events: a clinical model of shame-based and guilt-based PTSD.

Post-traumatic stress disorder is currently classified as an anxiety disorder with fear as the predominant emotion. This has led to the development of treatment techniques such as exposure aimed at alleviating fear. This article highlights the need to address other emotional responses, in particular shame and guilt, when assessing and treating PTSD. Hence, it presents two clinical models of shame-based PTSD and guilt-based PTSD. These models are offered as aids to clinicians in assessing and formulating cases of PTSD where shame and guilt are salient issues. The models highlight the importance of assessing meaning in the context of pre-existing schemas and address two pathways to the development of shame and/or guilt: schema congruence and schema incongruence. Several treatment implications are drawn from the models.

Guilt↗
PubMed2000

A mesoscale phytoplankton bloom in the polar Southern Ocean stimulated by iron fertilization.

Changes in iron supply to oceanic plankton are thought to have a significant effect on concentrations of atmospheric carbon dioxide by altering rates of carbon sequestration, a theory known as the 'iron hypothesis'. For this reason, it is important to understand the response of pelagic biota to increased iron supply. Here we report the results of a mesoscale iron fertilization experiment in the polar Southern Ocean, where the potential to sequester iron-elevated algal carbon is probably greatest. Increased iron supply led to elevated phytoplankton biomass and rates of photosynthesis in surface waters, causing a large drawdown of carbon dioxide and macronutrients, and elevated dimethyl sulphide levels after 13 days. This drawdown was mostly due to the proliferation of diatom stocks. But downward export of biogenic carbon was not increased. Moreover, satellite observations of this massive bloom 30 days later, suggest that a sufficient proportion of the added iron was retained in surface waters. Our findings demonstrate that iron supply controls phytoplankton growth and community composition during summer in these polar Southern Ocean waters, but the fate of algal carbon remains unknown and depends on the interplay between the processes controlling export, remineralisation and timescales of water mass subduction.

Atmosphere↗
PubMed2000

The odd man out

Explore the source record for details and available documents.

Journal Article↗
PubMed2000

What is a binge? The influence of amount, duration, and loss of control criteria on judgments of binge eating.

OBJECTIVE: We investigated the influence of amount of food eaten, duration of eating episode, and loss of control in judgments of eating episodes as binges. METHOD: Participants rated the degree to which the eating behavior of a female actress qualified as a "binge" after observing eight videotaped vignettes in which the amount of food eaten, apparent duration of eating episode, and loss of control were varied. Binge ratings were stable across a test-retest interval of 3-4 weeks, there was minimal observer drift, and the experimental variables were independently perceived. RESULTS: A repeated measures analysis of variance (ANOVA) on binge ratings revealed significant main effects for quantity and loss of control, and a significant Quantity x Time interaction. DISCUSSION: The results are consistent with the definitional criteria of a binge, underscore the independence of loss of control, and highlight the importance of the violation of dietary standards in judgments of binges. Moreover, they illustrate the reliability and sensitivity of the methodology, and its potential for further investigations of binge eating.

Adolescent↗
PubMed2000

Sorting biomolecules with microdevices.

Micro- and nanofabrication techniques have provided an unprecedented opportunity to create a designed world in which separation and fractionation technologies which normally occur on the macroscopic scale can be optimized by designing structures which utilize the basic physics of the process, or new processes can be realized by building structures which normally do not exist without external design. Since microfabrication is exceedingly sophisticated in its development, it is possible to design and construct highly creative microdevices which allow one to probe specific aspects of biological objects. We give examples of uses of micro- and nanofabrication which, as opposed to simply shrinking the size of the vessels or tubes used in macroscopic lab environments, utilize our understanding of the physics of the process to take advantage of fabrication technologies.

Animals↗
PubMed2000

Long-acting octreotide LAR compared with lanreotide SR in the treatment of acromegaly.

The use of somatostatin analogues for the treatment of acromegaly is now well established. Recently long-acting preparations of octreotide and lanreotide have been introduced. In this study we have assessed the efficacy and tolerability of the long acting somatostatin analogue octreotide LAR in patients with acromegaly, and compared it with lanreotide SR. Five patients with active acromegaly were recruited; they were treated with lanreotide SR for 6 months and then, following a wash-out period, received octreotide LAR for 6 months. They were assessed at baseline, 3- and 6-months, by clinical score, GH and IGF1. Adverse effects were carefully monitored. Both treatments effectively reduced GH and IGF1 levels. Four of five patients achieved a mean GH level of < 2.5 ng/ml with both drugs; with octreotide LAR only, these patients also had GH < 1 ng/ml after oral glucose loading. The clinical symptoms score improved significantly with octreotide LAR, as did the ring size; the clinical score correlated significantly with GH. Blood glucose was not adversely affected. All patients experienced minor GI symptoms with lanreotide SR, but less frequently with octreotide LAR. Both drugs caused biliary stasis and had a tendency to form biliary sludge. Octreotide LAR proved effective for the treatment of acromegaly and was well tolerated. Octreotide LAR had some advantages over lanreotide SR, although the differences were not great.

Acromegaly↗
PubMed2000

A quality assurance audit: phase III trial of maximal androgen deprivation in prostate cancer (TROG 96.01).

In 1997 the Trans-Tasman Radiation Oncology Group (TROG) performed a quality assurance (QA) audit of its phase III randomized clinical trial investigating the effectiveness of different durations of maximal androgen deprivation prior to and during definitive radiation therapy for locally advanced carcinoma of the prostate (TROG 96.01). The audit reviewed a total of 60 cases from 15 centres across Australia and New Zealand. In addition to verification of technical adherence to the protocol, the audit also incorporated a survey of centre planning techniques and a QA time/cost analysis. The present report builds on TROG's first technical audit conducted in 1996 for the phase III accelerated head and neck trial (TROG 91.01) and highlights the significant progress TROG has made in the interim period. The audit provides a strong validation of the results of the 96.01 trial, as well as valuable budgeting and treatment planning information for future trials. Overall improvements were detected in data quality and quantity, and in protocol compliance, with a reduction in the rate of unacceptable protocol violations from 10 to 4%. Audit design, staff education and increased data management resources were identified as the main contributing factors to these improvements. In addition, a budget estimate of $100 per patient has been proposed for conducting similar technical audits. The next major QA project to be undertaken by TROG during the period 1998-1999 is an intercentre dosimetry study. Trial funding and staff education have been targeted as the key major issues essential to the continued success and expansion of TROG's QA programme.

Androgen Antagonists↗
PubMed2000

Understanding suicide attempts by adolescent Hispanic females.

This article presents integrative model to aid clinicians in understanding suicide attempts by adolescent Hispanic females. On the basis of knowledge accumulated through clinical and research experience, the model describes a convergence of sociocultural, familial, developmental, and psychological factors that include considerations of family and parental functioning; adolescent female development; and the relationships of fathers, mothers, and daughters.

Adolescent↗
PubMed2000

Aligned microcontact printing of micrometer-scale poly-L-lysine structures for controlled growth of cultured neurons on planar microelectrode arrays.

We describe a method for producing high-resolution chemical patterns on surfaces to control the attachment and growth of cultured neurons. Microcontact printing has been extended to allow the printing of micron-scale protein lines aligned to an underlying pattern of planar microelectrodes. Poly-L-lysine (PL) lines have been printed on the electrode array for electrical studies on cultured neural networks. Rat hippocampal neurons showed a high degree of attachment selectivity to the PL and produced neurites that faithfully grew onto the electrode recording sites.

Animals↗
PubMed2000

Fluorometric high-throughput screening for inhibitors of cytochrome P450.

Rapid screening for cytochrome P450 inhibitors is part of the current paradigm for avoiding development of drugs likely to give clinical pharmacokinetic drug-drug interactions and associated toxicities. We have developed microtiter plate-based, direct, fluorometric assays for the activities of the principal human drug-metabolizing enzymes, CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4, as well as for CYP2A6, which is an important enzyme in environmental toxicology. These assays are rapid and compatible with existing high-throughput assay instrumentation. For CYP1A2, CYP2C8, CYP2C9, CYP2C19, and CYP2D6, the potency of enzyme inhibition (IC50) is consistent regardless of the probe substrate or assay method employed. In contrast, CYP3A4 inhibition for an individual inhibitor shows significant differences in potency (>300-fold) depending on the probe substrate being used. We have investigated these differences through the use of several structurally distinct fluorescent substrates for CYP3A4 and several classical substrate probes (e.g., testosterone, nifedipine, and midazolam), with a panel of known, clinically significant, CYP3A4 inhibitors. The use of multiple probe substrates appears to be needed to characterize the inhibition potential of xenobiotics for CYP3A4.

Coumarins↗