bluuebunny/crossref_metadata_2025 huggingface dataset:
Membrane Traffic and Muscle: Lessons from Human Disease
Authors: Dowling James J. , Gibbs Elizabeth M. , Feldman Eva L.
Published: February 2008

Like all mammalian tissues, skeletal muscle is dependent on membrane traffic for proper development and homeostasis. This fact is underscored by the observation that several human diseases of the skeletal muscle are caused by mutations in gene products of the membrane trafficking machinery. An examination of these diseases and the proteins that underlie them is instructive both in terms of determining disease pathogenesis and of understanding the normal aspects of muscle biology regulated by membrane traffic. This review highlights our current understanding of the trafficking genes responsible for human myopathies.
Metabolism of (4‐Phenoxyphenylsulfonyl)methylthiirane, a Selective Gelatinase Inhibitor
Authors: Celenza Giuseppe , Villegas‐Estrada Adriel , Lee Mijoon , Boggess Bill , Forbes Christopher , Wolter William R. , Suckow Mark A. , Mobashery Shahriar , Chang Mayland
Published: February 2008

(4‐Phenoxyphenylsulfonyl)methylthiirane (compound1) is a highly selective and potent inhibitor of gelatinases that shows considerable promise in animal models for cancer and stroke. The metabolism of compound1was investigated in mice, following intraperitoneal administration at 100 mg/kg. Eight metabolites were identified in plasma and urine. The primary routes of metabolism of1were hydroxylation at thepara‐position of the terminal phenyl ring, hydroxylation at the α‐methylene to the sulfonyl, which lead to the generation of a sulfinic acid, and cysteine conjugation of the thiirane ring. The cysteine adducts arose through addition of glutathione to the thiirane ring. The molecule is extensively metabolized and excreted in mice, yet it exhibits activityin vivo.
Utilization of Soybeans and Their Components through the Development of Textured Soy Protein Foods
Authors: Katayama M. , Wilson L.A.
Published: February 2008

ABSTRACT:  Textured soy protein (TSP), an extruded and fibrous‐structured product, is mainly used as meat analog or extender. Meat alternatives are third in sales in the U.S. soy food marketplace. A primary problem that limits the incorporation of more TSP into products is the undesirable “beany” flavor. The objective of this study was to develop the best formulation of TSP and vegetable‐based flavors to produce consumer acceptable “chicken” or “shrimp” flavored TSP using heat application processes. Four different types of commercial TSP (containing an average of 51% protein) strip‐shaped extruded with a narrow die (STRIP‐N) or with a wider die (STRIP‐W), shred‐shaped (SHRED) strips, and 1‐cm crouton‐shaped bits (BITs) were used. The TSPs were baked or deep‐fat fried after soaking in 5 different commercial vegetable‐based powered, liquid, or oil‐based flavors ranged from 0% to 22.3% concentrations. Four descriptive analyses with a minimum of 14 trained panelists were utilized to evaluate the attributes of the finished TSP. Proximate, color, and texture analyses were performed on each TSP product. All treatments were statistically analyzed. Both instrumental and sensory tests demonstrated that BIT had a significantly higher crispness than other TSP. The powder type of chicken flavor used for a consumer panel had a more intense flavor than others with the optimum hydration time, 15 min. A consumer test with 125 people was performed with the highest chicken flavored (22.3%) fried and baked BIT. Overall, 66% of the total consumers preferred the fried BIT to the baked BIT, and 31% preferred the baked BIT.
Echinococcus granulosus Infection in Spain
Authors: Carmena D. , Sánchez‐Serrano L. P. , Barbero‐Martínez I.
Published: February 2008

Cystic echinococcosis (CE) caused by the cestode Echinococcus granulosus is an endemic disease in Spain. Although specific control programmes initiated in the 1980s have led to marked reductions in CE infection rates in Spain, the disease still remains an important human and animal health problem in many regions of the country. Human incidence and livestock (including sheep, cattle, pigs and horses) prevalence data were gathered from national epidemiological surveillance information systems and regional institutions for the period 2000–2005. Additionally, data on the prevalence of E. granulosus infection in dogs were obtained from published literature. The most affected regions were those of the North Eastern, Central and Western parts of the country, (Autonomous Regions of Aragon, Castile‐La Mancha, Castile‐Leon, Extremadura, Navarre and La Rioja), where human CE incidence rates in the range of 1.1–3.4 cases per 105 inhabitants coexist with ovine/bovine CE prevalence rates up to 23%. Control programmes of hydatidosis/echinococcosis should be reinforced in these regions to reduce the prevalence of the disease.
Explanations for gender differences in sickness absence: evidence from middle-aged municipal employees from Finland
Authors: Laaksonen M , Martikainen P , Rahkonen O , Lahelma E
Published: February 2008

Objectives:

To examine gender differences in sickness absence spells of various lengths and to explain these differences by health status, working conditions and family-related factors.

Methods:

The study included 5470 female and 1464 male employees of the City of Helsinki surveyed at baseline in 2000–2. These survey data were linked to the employer’s sickness absence records until the end of 2005, providing a mean follow-up time of 3.9 years. Explanations for gender differences in self-certified (1–3 days) and medically confirmed absence spells of various lengths (4 days or more, more than 2 weeks, and more than 60 days) were examined using Poisson regression.

Results:

Women had 46% higher risk for self-certified sickness absence than men. In medically confirmed spells there was 34% female excess which gradually weakened with lengthening absence, and no differences were observed in spells longer than 60 days. Adjusting for physical functioning and self-reported diagnosed diseases clearly attenuated gender differences in sickness absence spells shorter than two weeks and fully explained them in longer absence spells. Physical work demands explained female excess in medically confirmed absence spells of all lengths, as did work fatigue in spells longer than two weeks. Psychosocial working conditions and family-related factors did not affect the gender differences. Physical health problems, physical work demands and work fatigue were somewhat more prevalent in women than in men, but their impact on sickness absence was similar in both genders.

Conclusions:

The overall gender differences in sickness absence are due to relatively short absence spells being more common among women. In longer sickness absence spells the female excess is mainly explained by heavier burden of ill-health and to a lesser extent by higher physical work demands among women. The authors found no support for greater vulnerability to health- and work-related problems among women as reasons for sickness absence.
Biological control of red alder using stem treatments with the fungus Chondrostereumpurpureum
Authors: Wall R.E.
Published: February 2008

Young red alder (Alnusrubra Bong.) trees were frilled at breast height and the frills inoculated with cultures of Chondrostereumpurpureum (Pers. ex Fr.) Pouzar in April, June, October, and in April of the following year. Over the ensuing 4 years, healing of the frills was less and tree mortality greater in trees inoculated with C. purpureum than in the uninoculated controls in the June and October treatments. Projected mortality for trees inoculated in June and October exceeded 80%. Among inoculation treatments, there was a strong correlation (r = 0.816) between percent tree mortality and the percentage of trees on which C. purpureum basidiocarps were recorded. It was concluded that summer or autumn inoculation with C. purpureum can be more effective in controlling red alder than frilling alone, and widens the treatment window for manual control.
Tissue-specific and light regulation of a larch ribulose-1,5-bisphosphate carboxylase promoter in transgenic tobacco
Authors: Campbell Michael A. , Neale David B. , Harvie Peter , Hutchison Keith W.
Published: February 2008

A chimeric gene composed of an eastern larch (Larix laricina (Du Roi) K. Koch) ribulose-1,5-bisphosphate carboxylase (RbcS) promoter linked to the β-glucuronidase (GUS) coding sequence was transferred to tobacco (Nicotianatabacum (L.)) via Agrobacteriumtumefaciens transformation. Based on GUS activity the larch RbcS promoter functioned in an organ-specific and light-regulated manner. Histochemical analysis revealed high levels of GUS activity in photosynthetically active tissues and low or undetectable activity in xylem and root tissues. Fluorometric analysis of GUS activity demonstrated that the larch RbcS promoter was expressed at a 10-fold higher level in leaf blades than in root tissue. Light-grown transgenic plants expressed GUS at a two-fold higher level than dark-grown individuals. These results suggest evolutionary conservation of tissue-specific RbcS promoter activity between gymnosperms and angiosperms but only weak conservation of the transduction mechanism for light regulation.
Canopy light transmittance in a chronosequence of mixed-species deciduous forests
Authors: Brown Martin J. , Parker Geoffrey G.
Published: February 2008

We measured the photosynthetically active radiation transmitted through the canopies of 24 Maryland forest stands, each around midday in midsummer. We then compared the observed values of PAR transmittance with stand age and measures of canopy structure. Generally, transmittance was low, with positively skewed frequency distributions. The geometric mean transmittance followed a distinct pattern with stand age. It was lowest (about 1%) in the youngest stands, increased to about 2.5% as forests approached ages of about 50 years, and then declined with age in the oldest sites (65–340 years). Transmittance was not significantly correlated with many simple measures of forest structure, including estimated aboveground biomass and leaf area index. Better predictions of transmittance used information on the vertical arrangement of the canopy, such as leaf area density. The results are contrary to the common assumptions that forests get consistently darker through time, and that transmittance is inversely proportional to the sheer mass or leaf area of the canopy. The Beer–Lambert extinction coefficient, k, changed with stand age and structure and was especially high in very young stands. We suggest that the variation in light transmittance, and k, can be explained by successional changes in the three-dimensional structure of the canopy.
Shoot and leaf growth in Fraxinuspennsylvanica and its relation to crown location and pruning
Authors: Remphrey W.R. , Davidson C.G.
Published: February 2008

Elongation of shoots in various crown locations, and of individual internodes and leaves of the leading shoot, were recorded at 2-day intervals throughout the 1991 growing season in four clones of Fraxinuspennsylvanica var. subintegerrima (Vahl) Fern. (green ash). Other trees were disbudded and pruned to a single leader. Using a logistic growth function, nonlinear regression equations were generated and parameter estimates were used to determine maximum growth rates. Terminal leading shoots had a longer growth duration and a greater maximum growth rate than lateral shoots. The pruning treatment resulted in larger shoots, which grew 2–3 weeks longer and had a higher maximum growth rate. Leaf emergence occurred at regular intervals but the rate of emergence varied among clones. Leaf maximum growth rates were not significantly different among clones. Leaf size declined acropetally whereas internode length increased and then decreased. The longest leaves and internodes had the highest maximum growth rates. The size and maximum growth rates of putative preformed leaves were larger than putative neoformed leaves. As a shoot expanded, growth of one internode tended to cease during the linear phase of growth of its associated leaf and that of the succeeding internode.
Ethanol synthesis in Douglas-fir logs felled in November, January, and March and its relationship to ambrosia beetle attack
Authors: Kelsey Rick G.
Published: February 2008

Phloem and sapwood from Douglas-fir, Pseudotsugamenziesii (Mirb.) Franco, logs felled in November, January, and March were sampled within 24 h of harvest and resampled on each subsequent felling date. In fresh logs, constitutive ethanol concentrations were similar among dates, but concentrations in the phloem were always greater than in the sapwood. In March, after 4 months on the ground, ethanol in November-felled logs had increased 4 times in the phloem and 83 times in the sapwood, which resulted in equal tissue concentrations. For January-felled logs, ethanol concentrations remained unchanged in log tops, but decreased in the bottoms and sides between January and March. α-Pinene concentrations did not differ among harvest dates or tissue types, but they did decrease when tissues respired anaerobically. When ambrosia beetles began attacking logs in March, tissues of November-felled logs contained the most ethanol. Attack densities of Trypodendronlineatum (Oliv.) and Gnathotrichusretusus (LeConte), counted in August, were highest in November-felled logs and lowest in March-felled logs and correlated with tissue ethanol concentrations from logs sampled in March. This beetle behavior is consistent with the expected response to a compound that functions as a beetle arrestant and attack stimulant. Absorption of rain, which could interfere with gas exchange between the atmosphere and log tissues, probably contributed to the establishment of anaerobic conditions in the logs.
Ionic Basis of on and off Persistent Activity in Layer III Lateral Entorhinal Cortical Principal Neurons
Authors: Tahvildari Babak , Alonso Angel A. , Bourque Charles W.
Published: February 2008

Principal neurons in layer III of the rat lateral entorhinal cortex (LEC) generate a self-sustained plateau potential and persistent spiking following the application of a brief suprathreshold excitatory stimulus delivered in the presence of the muscarinic receptor agonist carbachol. This persistent activity can be terminated by application of a second excitatory stimulus, and these cells can be repeatedly toggled between on and off states by consecutive excitatory stimuli. However, the ionic mechanisms that underlie the production of on and off states in layer III LEC neurons are unknown but seem to involve activity-dependent conductances, since they can be initiated by trains of action potentials evoked by either depolarizing current pulses applied to the cell or by repetitive spiking induced by activation of excitatory synaptic inputs. In this study, we obtained intracellular recordings from rat layer III LEC neurons in vitro, and a series of pharmacological and ionic substitution experiments were performed to identify mechanisms involved in the induction and termination of persistent spiking. Our data indicate that initiation of the on state depends on spike-evoked calcium influx and subsequent activation of calcium-activated nonselective cationic current. Moreover, we show that termination of persistent firing in response to an excitatory stimulus can be blocked by tetraethylammonium or iberiotoxin, suggesting that the activation of calcium-activated potassium current mediated by large conductance calcium-activated K+ (i.e., BK) channels is required to induce the off state.
The Weakest Link
Authors: Harvey William B.
Published: February 2008

Colleges and universities could be seen as being at the apex of a steep educational pyramid. Prospective entrants to the academy make their way up the pyramid by way of their experiences in elementary and secondary schools. Young people with financial means and social capital are likely to make it to the top of the pyramid with little difficulty. However, students of color, especially boys, are more likely to drop out, opt out, or be pushed out of school than they are to make a successful journey to the top. College and university presidents can help to change this situation by supporting precollege intervention programs on their campuses and in their communities. These programs can motivate and inspire students to pursue high academic achievement, and they help to establish a sense within these young people that attending college is an attainable goal, regardless of one's present social or financial circumstances.
Race Segregation Across the Academic Workforce
Authors: Jackson Jerlando F. L.
Published: February 2008

In terms of income and employment opportunities, previous studies have indicated that African American men fare less well than their White counterparts in the academic workforce, including a recent study by the author that found the hiring practices in higher education had a disparate effect on African American men. On the grounds that human capital and merit-based performance measures have proven to be critical criteria for decision making within the overall hiring practices in higher education, this study examined the extent to which these factors influence the observed representation of African American and White men in the academic workforce. This study found that both human capital and merit-based performance measures were good employment predictors for White men and, in contrast, were not good employment predictors for African American men in the academic workforce.
Religious Rhetoric and the Ethics of Public Discourse
Authors: Smith Rogers M.
Published: February 2008

Political theorists have argued for and against the propriety of a civic ethics of “public reason” that would set normative bounds on the expression of religious views in the public discourse of government officials and, to a lesser degree, citizens. This essay explores whether critics of ethical restraints on religious discourse have grounds to criticize the religious rhetoric of President George W. Bush. Quantitative and qualitative studies show that Bush has used a distinctive “prophetic” mode of religious expression more often than any modern predecessor. This sort of religious discourse is argued to be ethically dubious from the standpoints of most public reason advocates and most of their critics. Even as it champions democracy and adherence to the plans of divine providence, it discourages and de-legitimates democratic dissent and fails to provide the religious guidance it promises.
Implementing Interagency Collaborations
Authors: Sowa Jessica E.
Published: February 2008

Collaborative mechanisms are increasingly being used to deliver public services in the United States, with many scholars seeking to understand the operation and impact of these ventures. This article contributes to this research by breaking apart interagency collaborations used to deliver services, demonstrating the variations that can occur within a single form of collaborative service delivery. Examining collaborations to deliver early care and education services, this article demonstrates that scholars need to examine multiple collaborative ventures within policy fields to understand the variations that can arise during the implementation process and the implications of these variations for the public services.
A Closer Look at Trust Between Managers and Subordinates: Understanding the Effects of Both Trusting and Being Trusted on Subordinate Outcomes
Authors: Brower Holly H. , Lester Scott W. , Korsgaard M. Audrey , Dineen Brian R.
Published: February 2008

Despite previous calls to examine trust from the perspectives of both the manager and subordinate, most studies have exclusively focused on trust in the manager. The authors propose that trust in the subordinate has unique consequences beyond trust in the manager. Furthermore, they propose joint effects of trust such that subordinate behavior and intentions are most favorable when there is high mutual trust. Findings reveal unique relationships of trust in manager and trust in subordinate on performance, organizational citizenship behavior (OCB), and intentions to quit. Furthermore, the interaction of trust in manager and trust in subordinate predicts individual-directed OCB in the hypothesized direction.
Imag(in)ing September 11
Authors: King Erika G. , deYoung Mary
Published: February 2008

This study analyzes the Denver Post's reportage on the frame contest between the dominant narrative of the September 11 terrorist attacks set out by President Bush and a challenge to that narrative in an Internet essay by Professor Ward Churchill. The authors find that by refusing to interrogate Churchill's sociopolitical argument, reducing it to the offensive rhetorical trope “little Eichmanns” he used to describe the victims of the attacks, and pillorying Churchill as a person and scholar, the Post assured his counterframe would not achieve parity with the dominant frame. The authors interpret this as an example of media hegemony and situate the Post's coverage within a crisis of hegemony that left the “sacred core” of the Bush frame—American innocence and moral exceptionalism—vulnerable to contestation. Because the Churchill counterframe flagrantly transgressed that “sacred core,” it became the irresistible target of media hegemony strategies by the Denver Post.
Subjective Effect of September 11, 2001 Among Pregnant Women
Authors: Lewis Marilyn W. , Cavanagh Paul K. , Ahn Grace , Yoshioka Marianne R.
Published: February 2008

Prior history of trauma may sensitize individuals to subsequent trauma, including terrorist attacks. Using a convenience sample of secondary, cross-sectional data, pregnant women were grouped based on lifetime interpersonal violence history. Cumulative risk theory was used to evaluate the association of lifetime interpersonal violence history and subjective impact of the September 11, 2001 (9/11) terrorists attacks. Using hierarchical linear regression, cumulative risk theory was partially supported. Women with a history of only one type of interpfersonal violence reported greater effect of 9/11 than did women without a history, but women with both types of violence did not report a greater effect of 9/11 compared to women endorsing history of one type. These data corroborate the literature in that level of exposure to terrorist-related trauma predicts subjective reaction to the attacks. Future research with a larger sample and standardized instruments is warranted.
The Effect of Internet Use on Political Participation
Authors: Quintelier Ellen , Vissers Sara
Published: February 2008

Conflicting claims have been put forward regarding the effects of Internet use on real-life political participation. Some argue that Internet use, and the accompanying political resources, stimulates political participation; others fear that intensive Internet use is associated with a withdrawal from public life. This article's authors test both claims on a representative sample of 6,330 16-year-olds in Belgium. They investigate young people's behavior, assuming that young people are the most avid information and communication technologies users and the most susceptible to the influence of various socialization experiences. The authors introduce a distinction between time spent on the Internet (time-replacement hypothesis) and various activities performed online. Results show time on the Internet does not have an effect on the propensity to participate in public life. Although some online activities are clearly and significantly associated with offline political participation, it remains to be investigated whether this relation is a form of causality.
Developing an English-as-a-Second-Language Program for Foreign-Born Nursing Students at an Historically Black University in the United States
Authors: Brown Jennifer F.
Published: February 2008

The nursing department at Norfolk State University (NSU), a historically Black university located in Norfolk, Virginia, designed a program to increase the retention and success of foreign-born students challenged with English as a Second Language (ESL). Through strategies designed to address language, social, academic, and personal challenges, the program has led to improvements in student satisfaction and performance. This article reviews the literature related to educating foreign-born nursing students in the United States, discusses unique considerations for these students within minority-serving institutions, describes key components of program development, and evaluates NSU's program. To increase the diversity of the nursing workforce, other institutions are encouraged to consider replicating NSU's model for ESL-student retention and success.
Soluble but Not Platelet P-selectin Correlates With Spontaneous Platelet Aggregation: A Pilot Study
Authors: Cleanthis Marcus , Smout Jonathan , Bhattacharya Vishwanath , Ashour Hamdy , Dyker Alexander , Ashley Ford Gary , Mikhailidis Dimitri P , Stansby Gerard Patrick
Published: February 2008

Background. P-selectin (PS) is a marker of platelet activation measured on the platelet surface as platelet PS (pPS) or in serum as soluble PS (sPS). Controversy remains over the exact relationship between sPS, pPS, and other markers such as spontaneous platelet aggregation (SPA). Objective. To investigate correlations between pPS, sPS, and SPA in patients with peripheral arterial disease. Methods. SPA, pPS, and sPS levels were measured in venous blood sampled from patients following intermittent claudication (n = 18) or an acute stroke (n = 18). Results. SPA and sPS correlated significantly in the claudicants (Pearson correlation coefficient, r = 0.661; P = .0020) and stroke patients ( r = 0.514; P = .020). No significant correlation was identified between pPS and SPA, or sPS and pPS. Conclusions. The 2 methods of assessing PS are not comparable. Although pPS is accepted as a platelet activation marker, sPS may be a better indicator of aggregation represented by SPA.
Identifying Good Cops Early
Authors: White Michael D.
Published: February 2008

Police departments have traditionally assessed their performance through crime-related activity measures that often have little to do with good police work and offer little hope for prediction of exemplary performance. This article suggests some progress can be made in predicting superior performance by considering an earlier stage in a police officer's career where performance is well-defined and measurable: the police academy. Using recruit performance data ( n = 1,556) from a large metropolitan police department, the article uses linear and logistic regression, as well as Chi-square Automatic Indicator Detector (CHIAD), to identify predictors of superior performance in the academy. A number of interesting findings emerge with regard to factors that offer predictive value—reading level, age, gender, and race—and those that do not—college education, military experience, and residency. The article concludes with a discussion of the implications for recruitment, selection, and training, as well as for measuring and predicting performance on the street.
Selective release of molecules from Weibel-Palade bodies during a lingering kiss
Authors: Babich Victor , Meli Athinoula , Knipe Laura , Dempster John E. , Skehel Paul , Hannah Matthew J. , Carter Tom
Published: February 2008

Exocytosis of specialized endothelial cell secretory organelles, Weibel-Palade bodies (WPBs), is thought to play an important role in regulating hemostasis and intravascular inflammation. The major WPB core proteins are Von Willebrand factor (VWF) and its propolypeptide (Proregion), constituting more than 95% of the content. Although the composition of the WPBs can be fine-tuned to include cytokines and chemokines (eg, interleukin-8 [IL-8] and eotaxin-3), it is generally assumed that WPB exocytosis is inextricably associated with secretion of VWF. Here we show that WPBs can undergo a form of exocytosis during which VWF and Proregion are retained while smaller molecules, such as IL-8, are released. Imaging individual WPBs containing fluorescent cargo molecules revealed that during weak stimulation approximately 25% of fusion events result in a failure to release VWF or Proregion. The WPB membrane protein P-selectin was also retained; however, the membrane tetraspannin CD63 was released. Accumulation or exclusion of extracellular fluorescent dextran molecules ranging from 3 kDa to 2 mDa show that these events arise due to the formation of a fusion pore approximately 12 nm in diameter. The pore behaves as a molecular filter, allowing selective release of WPB core and membrane proteins. WPB exocytosis is not inextricably associated with secretion of VWF.
Pre-B cell colony-enhancing factor (PBEF)/visfatin: a novel mediator of innate immunity
Authors: Luk Tracy , Malam Zeenat , Marshall John C
Published: February 2008

Pre-B cell colony-enhancing factor (PBEF), also known as visfatin, is a highly conserved, 52-kDa protein found in living species from bacteria to humans. Originally a curiosity identified serendipitously in microarray studies but having no obvious functional importance, PBEF has now been shown to exert three distinct activities of central importance to cellular energetics and innate immunity. Within the cell, PBEF functions as a nicotinamide phosphoribosyl transferase, the rate-limiting step in a salvage pathway of nicotinamide adenine dinucleotide (NAD) biosynthesis. By virtue of this role, it can regulate cellular levels of NAD and so impact not only cellular energetics but also NAD-dependent enzymes such as sirtuins. Although it lacks a signal peptide, PBEF is released by a variety of cells, and elevated levels can be found in the systemic circulation of patients with a variety of inflammatory diseases. As an extracellular cytokine, PBEF can induce the cellular expression of inflammatory cytokines such as TNF-α, IL-1β, and IL-6. Finally, PBEF has been shown to be an adipokine expressed by fat cells that exerts a number of insulin mimetic and antagonistic effects. PBEF expression is up-regulated in a variety of acute and chronic inflammatory diseases including sepsis, acute lung injury, rheumatoid arthritis, inflammatory bowel disease, and myocardial infarction and plays a key role in the persistence of inflammation through its capacity to inhibit neutrophil apoptosis. This review summarizes the admittedly incomplete body of emerging knowledge about a remarkable new mediator of innate immunity.
A prospective evaluation of trochleoplasty for the treatment of patellofemoral dislocation and instability
Authors: Utting M. R. , Mulford J. S. , Eldridge J. D. J.
Published: February 2008

Trochlear dysplasia is a developmental condition characterised by an abnormally flat or dome-shaped trochlea and is an important contributory factor to patellofemoral instability and recurrent dislocation. We studied prospectively a series of 54 consecutive patients (59 knees) with patellofemoral instability secondary to trochlear dysplasia, who were treated by a trochleoplasty by a single surgeon between June 2002 and June 2007.

Pre- and post-operative scores were assessed by the patients and a satisfaction questionnaire was completed.

Of the 54 patients (59 knees) in the series, 39 (44 knees) were female and 15 (15 knees) were male. Their mean age at surgery was 21 years and 6 months (14 years 4 months to 33 years 11 months). In 40 patients (42 knees) the mean follow-up was for 24 months (12 to 58). One patient was unable to attend for follow-up. An analysis of the results of those patients followed up for at least 12 months showed a statistically significant improvement in outcome (p < 0.001 for all scores). Overall, 50 patients (92.6%) were satisfied with the outcome of their procedure.

The early results of trochleoplasty are encouraging in this challenging group of patients.
Kienböck’s disease
Authors: Schuind F. , Eslami S. , Ledoux P.
Published: February 2008

Kienböck’s disease is a form of osteonecrosis affecting the lunate. Its aetiology remains unknown. Morphological variations, such as negative ulnar variance, high uncovering of the lunate, abnormal radial inclination and/or a trapezoidal shape of the lunate and the particular pattern of its vascularity may be predisposing factors. A history of trauma is common. The diagnosis is made on plain radiographs, but MRI can be helpful early in the disease. A CT scan is useful to demonstrate fracture or fragmentation of the lunate. Lichtman classified Kienböck disease into five stages. The natural history of the condition is not well known, and the symptoms do not correlate well with the changes in shape of the lunate and the degree of carpal collapse. There is no strong evidence to support any particular form of treatment. Many patients are improved by temporary immobilisation of the wrist, which does not stop the progression of carpal collapse. Radial shortening may be the treatment of choice in young symptomatic patients presenting with stages I to III-A of Kienböck’s disease and negative ulnar variance. Many other forms of surgical treatment have been described.
Differential Regulation of Synaptic Plasticity and Cerebellar Motor Learning by the C-Terminal PDZ-Binding Motif of GluRδ2
Authors: Kakegawa Wataru , Miyazaki Taisuke , Emi Kyoichi , Matsuda Keiko , Kohda Kazuhisa , Motohashi Junko , Mishina Masayoshi , Kawahara Shigenori , Watanabe Masahiko , Yuzaki Michisuke
Published: February 2008

The δ2 glutamate receptor (GluRδ2) is predominantly expressed in Purkinje cells and plays crucial roles in cerebellar functions:GluRδ2−/−mice display ataxia and impaired motor learning. In addition, long-term depression (LTD) at parallel fiber (PF)–Purkinje cell synapses is abrogated, and synapse formation with PFs and climbing fibers (CFs) is severely disturbed inGluRδ2−/−Purkinje cells. Recently, we demonstrated that abrogated LTD was restored inGluRδ2−/−Purkinje cells by the virus-mediated expression of the wild-typeGluRδ2transgene (Tgwt) but not by that of mutantGluRδ2lacking the C-terminal seven residues to which several PDZ proteins bind (TgΔCT7). These results indicated that the C terminus of GluRδ2 conveys the signal(s) necessary for LTD. In contrast, other phenotypes ofGluRδ2−/−cerebellum, especially morphological abnormalities at PF and CF synapses, could not be rescued by virus-mediated transient expression. Thus, whether these phenotypes are mediated by the same signaling pathway remains unclear. To address these issues and to further delineate the function of GluRδ2in vivo, we generated transgenic mice that expressedTgΔCT7on aGluRδ2−/−background. Interestingly, althoughTgΔCT7restored abnormal PF and CF synapse formation almost completely, it could not rescue abrogated LTD inGluRδ2−/−Purkinje cells. Furthermore, although the gross motor discoordination ofGluRδ2−/−mice was restored, the cerebellar motor learning underlying delayed eyeblink conditioning remained impaired. These results indicate that LTD induction and motor learning are regulated by signaling via the C-terminal end of GluRδ2, whereas other functions may be differentially regulated by other regions of GluRδ2.
White Matter Vulnerability to Ischemic Injury Increases with Age Because of Enhanced Excitotoxicity
Authors: Baltan Selva , Besancon Elaine F. , Mbow Brianna , Ye ZuCheng , Hamner Margaret A. , Ransom Bruce R.
Published: February 2008

Stroke incidence increases with age and this has been attributed to vascular factors. We show here that CNS white matter (WM) is intrinsically more vulnerable to ischemic injury in older animals and that the mechanisms of WM injury change as a function of age. The mouse optic nerve was used to study WM function. WM function in older animals (12 months) was not protected from ischemic injury by removal of extracellular Ca2+or by blockade of reverse Na+/Ca2+exchange, as is the case with young adults. Ischemic WM injury in older mice is predominately mediated by glutamate release and activation of AMPA/kainate-type glutamate receptors. Glutamate release, attributable to reverse glutamate transport, occurs earlier and is more robust in older mice that show greater expression of the glutamate transporter. The observation that WM vulnerability to ischemic injury is age dependent has possible implications for the pathogenesis of other age-related CNS conditions.
A highly sensitive immunofluorometric assay for the measurement of aldosterone in small sample volumes: validation in mouse serum
Authors: Manolopoulou J , Bielohuby M , Caton S J , Gomez-Sanchez C E , Renner-Mueller I , Wolf E , Lichtenauer U D , Beuschlein F , Hoeflich A , Bidlingmaier M
Published: February 2008

Data on the involvement of aldosterone in the regulation of the renin–angiotensin–aldosterone system (RAAS) in rodents are still scarce, partly due to the high sample volumes needed by commercially available assays and to the very low aldosterone concentrations present. We have developed a highly sensitive and non-isotopic immunoassay, requiring a volume of only 50 μl serum for a duplicate measurement, employing a highly specific monoclonal antibody against aldosterone. The assay was validated in human and mouse samples and exhibited a linear working range from 10 to 1000 pg/ml. Values obtained after a chromatographic purification step correlated significantly to the dichloromethane extraction ordinarily used. Basal aldosterone values were measured in 75 mouse hybrids and found within the linear range (173±21 pg/ml), with no significant difference between males and females. Additionally, we show an increase in serum aldosterone in mice from 3 to 11 weeks of age. Mice of the same genetic background were treated with dexamethasone intraperitoneally (n=7), resulting in significantly decreased concentrations (35±3 vs 114±33 pg/ml in controls; P<0.001). In contrast, adrenocorticotropic hormone resulted in significantly increased serum aldosterone (603±119 pg/ml; n=7; P<0.001), as did the physiological stimulation of the RAAS by a high K+/low Na+ diet (1369±703 vs 172±36 pg/ml). In conclusion, we have developed and validated an extremely sensitive assay for determination of aldosterone concentrations from very small serum samples, which could be especially useful in pharmacological intervention studies in rodent models.
Plasma membrane expression of GnRH receptors: regulation by antagonists in breast, prostate, and gonadotrope cell lines
Authors: Finch Ann R , Sedgley Kathleen R , Caunt Christopher J , McArdle Craig A
Published: February 2008

In heterologous expression systems, human GnRH receptors (hGnRHRs) are poorly expressed at the cell surface and this may reflect inefficient exit from the endoplasmic reticulum. Here, we have defined the proportion of GnRHRs at the cell surface using a novel assay based on adenoviral transduction with epitope-tagged GnRHRs followed by staining and semi-automated imaging. We find that in MCF7 (breast cancer) cells, the proportional cell surface expression (PCSE) of hGnRHRs is remarkably low (<1%), when compared with Xenopus laevis (X) GnRHRs (∼40%). This distinction is retained at comparable whole cell expression levels, and the hGnRHR PCSE is increased by addition of the XGnRHR C-tail (h.XGnRHR) or by a membrane-permeant pharmacological chaperone (IN3). The IN3 effect is concentration- and time-dependent and IN3 also enhances the hGnRHR-mediated (but not h.XGnRHR- or mouse GnRHR-mediated) stimulation of [3H]inositol phosphate accumulation and the hGnRHR-mediated reduction in cell number. We also find that the PCSE for hGnRHRs and h.XGnRHRs is low and is greatly increased by IN3 in two hormone-dependent cancer lines, but is higher and less sensitive to IN3 in a gonadotrope line. Finally, we show that the effect of IN3 on hGnRHR PCSE is not mimicked or blocked by two peptide antagonists although they do increase the PCSE for h.XGnRHRs, revealing that an antagonist-occupied cell surface GnRHR conformation can differ from that of the unoccupied receptor. The low PCSE of hGnRHRs and this novel peptide antagonist effect may be important for understanding GnRHR function in extrapituitary sites.
Peripheral administration of kisspeptin-10 increases plasma concentrations of GH as well as LH in prepubertal Holstein heifers
Authors: Kadokawa H , Matsui M , Hayashi K , Matsunaga N , Kawashima C , Shimizu T , Kida K , Miyamoto A
Published: February 2008

This study was conducted to estimate the effects of kisspeptin-10 on blood concentrations of LH and GH in prepubertal dairy heifers. Heifers received a single injection of 1 mg kisspeptin-10 (n=5) or saline (n=5) intravenously, and serial blood samples were collected at 15-min intervals to analyze the response curves of both LH and GH after injection. Peak-shaped responses were observed for concentrations of LH and GH, and the peaks were observed at 27±3 and 75±9 min, respectively, after injection, only in heifers injected with kisspeptin-10. These data suggest various possible important links among kisspeptin, the reproductive axis, and also the somatotropic axis in prepubertal Holstein heifers.
Mitochondrial Capacity in Skeletal Muscle Is Not Stimulated by Weight Loss Despite Increases in Insulin Action and Decreases in Intramyocellular Lipid Content
Authors: Toledo Frederico G.S. , Menshikova Elizabeth V. , Azuma Koichiro , Radiková Zofia , Kelley Carol A. , Ritov Vladimir B. , Kelley David E.
Published: February 2008

OBJECTIVE— In obesity and type 2 diabetes, exercise combined with weight loss increases skeletal muscle mitochondrial capacity. It remains unclear whether mitochondrial capacity increases because of weight loss, improvements in insulin resistance, or physical training. In this study, we examined the effects of an intervention of weight loss induced by diet and compared these with those of a similar intervention of weight loss by diet with exercise. Both are known to improve insulin resistance, and we tested the hypothesis that physical activity, rather than improved insulin resistance, is required to increase mitochondrial capacity of muscle.

RESEARCH DESIGN AND METHODS— Sixteen sedentary overweight/obese volunteers were randomized to a 16-week intervention of diet (n = 7) or diet plus exercise (n = 9). Insulin sensitivity was measured using euglycemic clamps. Mitochondria were examined in muscle biopsies before and after intervention. We measured mitochondrial content and size by electron microscopy, electron transport chain (ETC) activity, cardiolipin content, and mitochondrial DNA content. Intramyocellular content of lipid (IMCL) and fiber-type distribution were determined by histology.

RESULTS— The diet-only and diet plus exercise groups achieved similar weight loss (10.8 and 9.2%, respectively); only the diet plus exercise group improved aerobic capacity. Insulin sensitivity improved similarly in both groups. Mitochondrial content and ETC activity increased following the diet plus exercise intervention but remained unchanged following the diet-only intervention, and mitochondrial size decreased with weight loss despite improvement in insulin resistance. IMCL decreased in the diet-only but not in the diet plus exercise intervention.

CONCLUSIONS— Despite similar effects to improve insulin resistance, these interventions had differential effects on mitochondria. Clinically significant weight loss in the absence of increased physical activity ameliorates insulin resistance and IMCL but does not increase muscle mitochondrial capacity in obesity.
Quantifying successional changes in response to forest disturbances
Authors: Penman Trent D. , Binns Doug L. , Kavanagh Rodney P.
Published: February 2008

Question: Can dissimilarity measures of individual plots be used to forecast the driving factors among various anthropogenic disturbances influencing understorey successional changes?

Location: Yambulla State Forest, south‐eastern Australia (37°14'S, 149°38'E).

Methods: Assessments of understorey vegetation communities were taken prior to anthropogenic disturbances and at three subsequent time periods representing a period of 15 years post‐disturbance. Dissimilarities were calculated from the original assessment and modelled in a Bayesian framework to examine the influence of logging, number of prescribed burns and time.

Results: All sites underwent significant changes over time independently of the imposed management regimes. Logging resulted in an immediate change in vegetation assemblage which decreased in the subsequent assessments. The number of prescribed fires brought greater change in the shrub vegetation assemblages, but less change in the ground species vegetation assemblages.

Conclusions: The anthropogenic disturbances did have some role in the changes of vegetation assemblages but these were minimal. The ongoing changes appear to be a natural response to the last wildfire, which passed through the study area in 1973 (13 years prior to the study). Forest management practices should consider the influence of wildfire succession when planning for the conservation of biodiversity.
Sudden Cardiac Death Caused by Migration of a TrapEase Inferior Vena Cava Filter: Case Report and Review of the Literature
Authors: Haddadian Babak , Shaikh Fareed , Djelmami‐Hani Mohamed , Shalev Yoseph
Published: February 2008

Case

A 43‐year‐old female presented with sudden onset of palpitations, chest pain, and shortness of breath associated with hypoxemia. A helical computed tomography (CT) scan of the chest revealed a large saddle pulmonary embolism. Intravenous tPA relieved the shortness of breath and improved the hypoxemia. Inferior vena cava (IVC) filter (TrapEase, Cordis Corp., Miami, FL, USA) was placed. On day 6 of her hospitalization, she went into cardiopulmonary arrest while walking back from the rest room. The patient died despite a prolonged attempt at cardiopulmonary resuscitation. At that time, ventricular tachycardia and then ventricular fibrillation were recorded. Autopsy of the heart showed the IVC filter entrapped within the tricuspid valve.

Discussion

The incidence of IVC filter migration ranges from 0.3 to 6% with rare migration to the heart or lung (0.1–1.25%). Sudden cardiac death from migration of IVC filter is extremely rare. We report the first case of sudden cardiac death caused by migration of the TrapEase filter to the heart. There are two reports in the literature of death from migrating Greenfield and Antheor filters.

Conclusion

An IVC filter migration to the heart, although rare, can cause serious arrhythmia and sudden cardiac death. Copyright © 2008 Wiley Periodicals, Inc.