Posted by: princekhaled | March 8, 2009

March 2009

Assimacopoulos AP(*), Strandberg KL, Rotschafer JH, & Schlievert PM (2009).
Extreme Pyrexia and Rapid Death Due to Staphylococcus aureus Infection: Analysis of 2 Cases.
Clinical Infectious Diseases 48(5): 612-614.

We describe unusual Staphylococcus aureus infections in 2 patients. The infections were characterized by extreme pyrexia and rapid death. Both causative organisms produced a deletion mutant form of toxic shock syndrome toxin-1 and variant enterotoxin C, which may have caused pyrexia and death.

(*) Sanford School of Medicine of the University of South Dakota, Sioux Falls

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Ballal A(*) (2009).
sarZ, a sarA Family Gene, Is Transcriptionally Activated by MgrA and Is Involved in the Regulation of Genes Encoding Exoproteins in Staphylococcus aureus.
Journal of Bacteriology 191(5): 1656-1665.

The expression of genes involved in the pathogenesis of Staphylococcus aureus is controlled by global regulatory loci, including two-component regulatory systems and transcriptional regulators (e.g., sar family genes). Most members of the SarA family have been partially characterized and shown to regulate a large numbers of target genes. Here, we describe the characterization of sarZ, a sarA paralog from S. aureus, and its regulatory relationship with other members of its family. Expression of sarZ was growth phase dependent with maximal expression in the early exponential phase of growth. Transcription of sarZ was reduced in an mgrA mutant and returned to a normal level in a complemented mgrA mutant strain, which suggests that mgrA acts as an activator of sarZ transcription. Purified MgrA protein bound to the sarZ promoter region, as determined by gel shift assays. Among the sarA family of genes analyzed, inactivation of sarZ increased sarS transcription, while it decreased agr transcription. The expression of potential target genes involved in virulence was evaluated in single and double mutants of sarZ with mgrA, sarX, and agr. Northern and zymogram analyses indicated that the sarZ gene product played a role in regulating several virulence genes, particularly those encoding exoproteins. Gel shift assays demonstrated nonspecific binding of purified SarZ protein to the promoter regions of the sarZ-regulated target genes. These results demonstrate the important role played by SarZ in controlling regulatory and virulence gene expression in S. aureus.

(*) Division of Basic Biomedical Sciences, University of South Dakota, Vermillion, South Dakota 57069

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Carr D(*), Davies T(*), & Lavin A(*) (2009).
The Effect of Business faculty Attire on Student Perceptions of the Quality of Instruction and Program Quality.
College Student Journal 43(1): 45-55.

What professors do, how they behave, and how they look arguably can be as significant as, if not more important than, the content discussed in the classroom. There is little disagreement that attire has communicative power, and the topic has been the subject of research for years due to its cultural and social significance. While the debate regarding effective instruction continues, it is apparent that the professional appearance and attire of the professor has a positive impact on the students’ perceptions of a number of traits that are often considered in the evaluation of an academician. The results of this study suggest that this favorable attitude leaves students with a more positive perception of the professor, course, program, and university.

(*) Beacom School of Business The University of South Dakota

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Chen DG, & Lio YL(*) (2009).
A Novel Estimation Approach for Mixture Transition Distribution Model in High-Order Markov Chains.
Communications in Statistics: Simulation & Computation 38(5): 990-1003.

A transformation is proposed to convert the nonlinear constraints of the parameters in the mixture transition distribution (MTD) model into box-constraints. The proposed transformation removes the difficulties associated with the maximum likelihood estimation (MLE) process in the MTD modeling so that the MLEs of the parameters can be easily obtained via a hybrid algorithm from the evolutionary algorithms and/or quasi-Newton algorithms for global optimization. Simulation studies are conducted to demonstrate MTD modeling by the proposed novel approach through a global search algorithm in R environment. Finally, the proposed approach is used for the MTD modelings of three real data sets.

(*) Department of Mathematical Sciences, University of South Dakota, Vermillion, South Dakota, USA

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Choi H-s(*), Whitney Y(*), Korcuska JS(*), & Proctor TB(*) (2008).
Consultation practices between school counselors and school psychologists: Implications for training and practice.
Journal of Applied School Psychology 24(2): 303-318.

This study examined the extent of partnership between school counselors and school psychologists via consultation. Stratified random samples of 150 school counselors and 150 school psychologists who are members of ASCA and NASP, respectively, were surveyed using a 12- item questionnaire. Despite current trends toward a partnership approach to serving children, limited consultative efforts were noted between school counselors and school psychologists. Implications of the findings and recommendations for practitioners and training programs are discussed.

(*) University of South Dakota, Vermillion, SD, US

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Fikretoglu D, & Elhai JD(*) (2009).
Predictors of Likelihood and Intensity of Past-Year Mental Health Service Use in an Active Canadian Military Sample.
Psychiatric Services 60(3): 358-366.

OBJECTIVE: This study examined associations between sociodemographic, military, and psychiatric need variables and past-year mental health service use among active Canadian military members. The likelihood and intensity of services were examined across two provider types—mental health providers and medical providers. METHOD:S: Data were drawn from the first epidemiological survey of mental health in the Canadian Forces, conducted by Statistics Canada in 2002. Survey instruments included the Composite International Diagnostic Interview, which was used to assess mental health and service use. RESULTS: Of the 8,441 military members who participated in the survey, 14.5% (N=1,220) met criteria for having a mental disorder in the past year. However, of the 8,441 only 9.1% (N=767) contacted a mental health provider in the past year for mental health problems; even fewer (N=539, 6.4%) contacted a medical provider. Across the two provider types, the majority of those seeing a provider reported five or fewer mental health visits in the past year. In univariate and multivariate analyses across the two provider types, psychiatric need variables were consistently associated with both greater service use likelihood and intensity. In multivariate analyses, lower military rank was consistently associated with both greater service use likelihood and intensity. CONCLUSION:S: Of the entire military sample, only a small percentage used mental health services. The observed associations between military and psychiatric need variables and mental health service use in this study should be used by military health care providers and administrators to increase mental health service use among those most at risk of not using services.

(*) Disaster Mental Health Institute, University of South Dakota, Vermillion

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Gray MJ, Elhai JD(*), Owen JR, & Monroe R(*) (2009).
Psychometric Properties of the Trauma Assessment for Adults.
Depression & Anxiety (1091-4269) 26(2): 190-195.

Background: The Trauma Assessment for Adults (TAA) was developed to facilitate the assessment of exposure to traumatic events that could result in posttraumatic stress disorder (PTSD). The TAA inquires about numerous potentially traumatic events that an individual may have experienced. Although the TAA has been used extensively for clinical and research purposes, its psychometric properties have never been formally evaluated. The objective of the present investigation was to evaluate the psychometric properties of this frequently used measure. Methods: The studies reported here describe the performance of the TAA in two samples—college undergraduates (N=142) and community mental health center clients (N=67). Among undergraduates, 1-week temporal stability was evaluated and, in both samples, item- and scale-level convergence of the TAA with an established trauma exposure measure was assessed. Convergence of the TAA with clinically related constructs was also evaluated. Results: The TAA exhibited adequate temporal stability (r=.80) and satisfactory item-level convergence with existing measures of trauma history among college students. In the clinical sample, the TAA again converged well with an established measure of trauma exposure (r=.65). It was not as strongly predictive, in either sample, of trauma-related distress relative to an alternate trauma exposure measure. Conclusion: Although it performs satisfactorily, the TAA does not appear to be superior to other existing measures of trauma exposure.

(*) Disaster Mental Health Institute, University of South Dakota, Vermillion, South Dakota

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Li W(*), & Keifer J(*) (2009).
BDNF-induced synaptic delivery of AMPAR subunits is differentially dependent on NMDA receptors and requires ERK.
Neurobiology of Learning & Memory 91(3): 243-249.

Previous studies using an in vitro model of eyeblink classical conditioning in turtles suggest that increased numbers of synaptic AMPARs supports the acquisition and expression of conditioned responses (CRs). Brain-derived neurotrophic factor (BDNF) and its associated receptor tyrosine kinase, TrkB, is also required for acquisition of CRs. Bath application of BDNF alone induces synaptic delivery of GluR1- and GluR4-containing AMPARs that is blocked by coapplication of the receptor tyrosine kinase inhibitor K252a. The molecular mechanisms involved in BDNF-induced AMPAR trafficking remain largely unknown. The aim of this study was to determine whether BDNF-induced synaptic AMPAR incorporation utilizes similar cellular mechanisms as AMPAR trafficking that occurs during in vitro classical conditioning. Using pharmacological blockade and confocal imaging, the results show that synaptic delivery of GluR1 subunits during conditioning or BDNF application does not require activity of NMDARs but is mediated by extracellular signal-regulated kinase (ERK). In contrast, synaptic delivery of GluR4-containing AMPARs during both conditioning and BDNF application is NMDAR- as well as ERK-dependent. These findings indicate that BDNF application mimics AMPAR trafficking observed during conditioning by activation of some of the same intracellular signaling pathways and suggest that BDNF is a key signal transduction element in postsynaptic events that mediate conditioning.

(*) Neuroscience Group, Division of Basic Biomedical Sciences, University of South Dakota School of Medicine, 414 E. Clark Street, Vermillion, SD 57069, USA

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Long ME(*), & Quevillon R(*) (2009).
Imagery Rescripting in the Treatment of Posttraumatic Stress Disorder.
Journal of Cognitive Psychotherapy 23(1): 67-76.

The use of imagery in psychotherapy has received surprisingly little attention from researchers despite its long history in psychology and the significance of imagery in a number of psychological disorders. One procedure warranting increased attention is imagery rescripting, an imagery technique in which an image is modified in some way to decrease distress. Imagery rescripting is relatively new with a small but growing empirical base. This article briefly reviews hypothesized mechanisms for therapeutic change via imagery techniques, emphasizing imagery rescripting, and how they might be relevant in the treatment of posttraumatic stress disorder (PTSD). We review studies employing imagery rescripting as a component of treatment, followed by recommendations for future direction.

(*) Disaster Mental Health Institute, The University of South Dakota, Vermillion

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Santo S(*), Engstrom M, Reetz L(*), Schweinle W(**), & Reed K(*) (2009).
Faculty Productivity Barriers and Supports at a School of Education.
Innovative Higher Education 33(4): 1-13.

All programs in a midwestern university recently embarked on a path to help increase the scholarly productivity of faculty. The effort to develop a research emphasis within the School of Education required determining the needs of tenure-track faculty regarding meeting the new requirements. The purposes of our study were to investigate these needs and identify the individual, environmental, and leadership factors that affect faculty productivity. Findings revealed a need to transform the School’s service and teaching culture to a culture of research and scholarship. Recommendations for helping other schools of education to become more research-oriented are provided. While the study focuses on data from a particular School of Education, the implications may generalize to faculty productivity within other institutions, particularly within professional schools.

(*) School of Education, University of South Dakota Vermillion SD USA
(**) Health Sciences, University of South Dakota Vermillion SD USA

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Scholl JL(*), Feng N(**), Watt MJ(*), Renner KJ(**), & Forster GL(*) (2009).
Individual differences in amphetamine sensitization, behavior and central monoamines.
Physiology & Behavior 96(3): 493-504.

Repeated amphetamine treatment results in behavioral sensitization in a high percentage of rats. Alterations to plasma corticosterone, neural monoamines and stress behavior can accompany amphetamine sensitization. Whether these changes occur following repeated amphetamine treatment in the absence of behavioral sensitization is not known. Male Sprague–Dawley rats were treated with amphetamine (2.5 mg/kg, i.p.) or saline once daily for 6 days. Amphetamine-induced locomotion and stereotypy, open-field anxiety behavior, plasma corticosterone and limbic monoamines were measured during withdrawal. Sixty-two percent of amphetamine-treated rats showed behavioral sensitization over the test periods. Only amphetamine-sensitized rats showed increased latency to enter the center of the open-field, as well as increased plasma corticosterone when compared to saline-treated controls. Amphetamine-sensitized rats showed increased dopamine concentrations in the shell of the nucleus accumbens and increased serotonin concentrations in the dorsal hippocampus, which were not observed in amphetamine-treated non-sensitized rats. These findings suggest that anxiety behavior, plasma corticosterone and limbic monoamines concentrations are altered by repeated amphetamine (2.5 mg/kg) treatment, and that these neuroendocrine and behavioral changes are often associated with sensitization to the psychostimulant effects of amphetamine.

(*) Basic Biomedical Sciences & Neuroscience Group, Sanford School of Medicine, University of South Dakota, 414 E. Clark St. Vermillion, SD, 57069, USA
(**) Department of Biology & Neuroscience Group, University of South Dakota, 414 E. Clark St. Vermillion, SD, 57069, USA

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Shokeen S(*) (2009).
An Intramolecular Upstream Helix Ensures the Stability of a Toxin-Encoding RNA in Enterococcus faecalis.
Journal of Bacteriology 191(5): 1528-1536.

The par stability determinant is required for the stable inheritance of the plasmid pAD1 in its native host, Enterococcus faecalis. It is the only antisense RNA-regulated addiction module identified to date in gram-positive bacteria. It encodes two small, convergently transcribed RNAs, RNA I and RNA II. RNA I encodes the Fst toxin and RNA II acts as the antitoxin by interacting with RNA I posttranscriptionally. As the toxin-encoding component of the system, it is important that RNA I is more stable than RNA II. This study reveals that a helix sequestering the 5′ end of RNA I plays a crucial role in maintaining the stability of the RNA I. An adjacent structure previously determined to regulate Fst translation was not required to enhance stability. Results indicated that endoribonuclease J2 contributes significantly to the degradation of a mutant disrupting the upstream helix (UH) of RNA I in Bacillus subtilis. Finally, it was shown that interaction with RNA II stabilized the UH mutant of RNA I.

(*) Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, South Dakota 57069

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Lenné T, Garvey CJ, Koster KL(*), & Bryant G (2009).
Effects of Sugars on Lipid Bilayers during Dehydration – SAXS/WAXS Measurements and Quantitative Model.
Journal of Physical Chemistry B 113(8): 2486-2491.

We present an X-ray scattering study of the effects of dehydration on the bilayer and chain—chain repeat spacings of dipalmitoylphosphatidylcholine bilayers in the presence of sugars. The presence of sugars has no effect on the average spacing between the phospholipid chains in either the fluid or gel phase. Using this finding, we establish that for low sugar concentrations only a small amount of sugar exclusion occurs. Under these conditions, the effects of sugars on the membrane transition temperatures can be explained quantitatively by the reduction in hydration repulsion between bilayers due to the presence of the sugars. Specific bonding of sugars to lipid headgroups is not required to explain this effect.

(*) The University of South Dakota, Vermillion, South Dakota

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Weaver KE(*), Kwong SM, Firth N, & Francia MV (2009).
The replicons of Gram-positive bacteria: A family of broadly distributed but narrow host range plasmids.
Plasmid 61(2): 94-109.

The pheromone-responsive conjugative plasmids of Enterococcus faecalis and the multiresistance plasmids pSK1 and pSK41 of Staphylococcus aureus are among the best studied plasmids native to Gram-positive bacteria. Although these plasmids seem largely restricted to their native hosts, protein sequence comparison of their replication initiator proteins indicates that they are clearly related. Homology searches indicate that these replicons are representatives of a large family of plasmids and a few phage that are widespread among the low G+C Gram-positive bacteria. We propose to name this family the family of replicons after the annotated conserved domain that the initiator protein contains. Detailed sequence comparisons indicate that the initiator protein phylogeny is largely congruent with that of the host, suggesting that the replicons have evolved along with their current hosts and that intergeneric transfer has been rare. However, related proteins were identified on chromosomal regions bearing characteristics indicative of ICE elements, and the phylogeny of these proteins displayed evidence of more frequent intergeneric transfer. Comparison of stability determinants associated with the replicons suggests that they have a modular evolution as has been observed in other plasmid families.

(*) Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, 414 East Clark Street, Vermillion, SD 57069, USA
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Kerby, Jacob L., and Andrew Storfer.
Combined Effects of Atrazine and Chlorpyrifos on Susceptibility of the Tiger Salamander to Ambystoma Tigrinum Virus.
Ecohealth, 6 (2009): 91-98.

Several hypotheses have been examined as potential causes of global amphibian declines, including emerging infectious diseases and environmental contaminants. Although these factors are typically studied separately, animals are generally exposed to both stressors simultaneously. We examined the effects of the herbicide atrazine and the insecticide chlorpyrifos on the susceptibility of tiger salamander larvae, Ambystoma tigrinum, to a viral pathogen, Ambystoma tigrinum virus (ATV). Environmentally relevant concentrations of atrazine (0, 20, 200 mu g/L) and chlorpyrifos (0, 2, 20, 200 mu g/L) were used along with ATV in a fully factorial experimental design whereby individually housed, 4-week-old larvae were exposed for 2 weeks. Atrazine alone was not lethal to larvae, and chlorpyrifos alone was lethal only at the highest concentration. When combined with ATV, chlorpyrifos increased susceptibility to viral infection and resulted in increased larval mortality. A significant interactive effect between atrazine and ATV was detected. Atrazine treatments slightly decreased survival in virus-exposed treatments, yet slightly increased survival in the virus-free treatments. These findings corroborate earlier research on the impacts of atrazine, in particular, on disease susceptibility, but exhibit greater effects (i.e., reduced survival) when younger larvae were examined. This study is the first of its kind to demonstrate decreases in amphibian survival with the combination of pesticide and a viral disease. Further examination of these multiple stressors can provide key insights into potential significance of environmental cofactors, such as pesticides, in disease dynamics.

Biology Department, University of South Dakota, 414 E Clark Street, Vermillion, SD 57069, United States
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