Bundling of actin filaments by aorta caldesmon is not related to its regulatory function

AbstractCa2+-sensitive thin filaments from vascular smooth muscle were disassembled into their constituent proteins, actin, tropomyosin and caldesmon. Caldesmon bound to both actin and to actin-tropomyosin and inhibited actin-tropomyosin activation of skeletal muscle myosin MgATPase. It also promoted the aggregation of actin or actin-tropomyosin into parallel aligned bundles. Quantitative electron microscopy measurements showed that with 1.1 μM actin-tropomyosin, 1.6 ± 0.5% (n = 3) of the filaments were in bundles. At 0.073 μM, caldesmon inhibited MgATPase activity by 50%, whereas bundling was 3.0 ± 1.3% (n = 4). At 0.37 μM caldesmon, MgATPase inhibition was 83% while 28.1 ± 6.9% (n = 4) of filaments were in bundles. Experiments at 4.4 μM in which MgATPase and bundling were measured in the same samples gave similar results. Small bundles of 2–3 filaments showed the most frequent occurrence at 1.1 μM actin. At 4.4 μM actin the most common bundle size was 3-5 filaments, with the occasional occurrence of large bundles consisting of up to 120 filaments. The incidence of bundling was the same in the presence and absence of tropomyosin. Thus caldesmon can induce the formation of actin bundles but this property bears no relationship to its inhibition of MgATPase activity

Early-type stars observed in the ESO UVES Paranal Observatory Project - V. Time-variable interstellar absorption

The structure and properties of the diffuse interstellar medium (ISM) on small scales, sub-au to 1 pc, are poorly understood. We compare interstellar absorption-lines, observed towards a selection of O- and B-type stars at two or more epochs, to search for variations over time caused by the transverse motion of each star combined with changes in the structure in the foreground ISM. Two sets of data were used: 83 VLT- UVES spectra with approximately 6 yr between epochs and 21 McDonald observatory 2.7m telescope echelle spectra with 6 - 20 yr between epochs, over a range of scales from 0 - 360 au. The interstellar absorption-lines observed at the two epochs were subtracted and searched for any residuals due to changes in the foreground ISM. Of the 104 sightlines investigated with typically five or more components in Na I D, possible temporal variation was identified in five UVES spectra (six components), in Ca II, Ca I and/or Na I absorption-lines. The variations detected range from 7\% to a factor of 3.6 in column density. No variation was found in any other interstellar species. Most sightlines show no variation, with 3{\sigma} upper limits to changes of the order 0.1 - 0.3 dex in Ca II and Na I. These variations observed imply that fine-scale structure is present in the ISM, but at the resolution available in this study, is not very common at visible wavelengths. A determination of the electron densities and lower limits to the total number density of a sample of the sightlines implies that there is no striking difference between these parameters in sightlines with, and sightlines without, varying components.Comment: 19 pages, 11 figures, accepted for publication in MNRA

Access to Care, Reporting Behaviors, and Quality of Athletic Training Service Interactions for Reserve Officers\u27 Training Corps cadets

Purpose: Reserve Officers’ Training Corps (ROTC) programs prepare student-civilians to become leaders through strenuous physical and leadership training. Unlike their student-athlete counterparts who have direct access to athletic training services, ROTC cadets may or may not have a healthcare provider available. The purpose of this study was to examine the access to care and reporting behaviors of ROTC cadets with a secondary aim exploring the quality of healthcare service interactions relative to patient-centered care. Methods: An online survey assessed access to care using a self-report tool on the type of medical providers available to the ROTC cadets (n=132, age=20±3 y) dispersed between the Army, Navy, Air Force, and Marines, and their illness/injury history and reporting behaviors. The participants who sought care for an injury/illness also completed the Consultation and Relational Empathy tool to measure the level of patient-centered care by the healthcare provider with follow-up analysis using the Consultation Care Measure tool for all athletic training service interactions. Data were analyzed using descriptive statistics. Results: ROTC cadets reported access to 2±1 healthcare providers including a designated civilian physician (26.5%), athletic trainer (23.5%), and ROTC peer first responder (14.4%). However, 50.8% of respondents stated they were unsure what healthcare providers were available. In total, 22.7% of cadets reported being injured and 26.5% reported being sick/ill while participating in ROTC activities. Of those who stated they had sustained an injury during ROTC, 59.9% seldomly or never reported their injury. The ROTC cadets who sought healthcare expressed they were satisfied with their injury (35.96±10.60) and illness (35.48±13.10) treatment from a patient-centered viewpoint. Conclusions: The ROTC cadets reported a general unfamiliarity with the healthcare providers available to them. Despite the reporting behaviors, the cadets reported being satisfied with the care they received

A report card approach to describe temporal and spatial trends in parameters for coastal seagrass habitats

Report cards that are designed to monitor environmental trends have the potential to provide a powerful communication tool because they are easy to understand and accessible to the general public, scientists, managers and policy makers. Given this functionality, they are increasingly popular in marine ecosystem reporting. We describe a report card method for seagrass that incorporates spatial and temporal variability in three metrics—meadow area, species and biomass—developed using long-term (greater than 10 years) monitoring data. This framework summarises large amounts of spatially and temporally complex data to give a numeric score that provides reliable comparisons of seagrass condition in both persistent and naturally variable meadows. We provide an example of how this is applied to seagrass meadows in an industrial port in the Great Barrier Reef World Heritage Area of north-eastern Australia

Genetic and Antigenic Analysis of the First A/New Caledonia/20/99-like H1N1 Influenza Isolates Reported in the Americas

From February through May of 1999, 13 cases of Influenza A virus (FLUAV), type H1N1 were reported at a Department of Defense influenza surveillance sentinel site in Lima, Peru. Genetic and antigenic analysis by hemagglutination inhibition and direct nucleotide sequencing of the HA1 region of the hemagglutinin gene were performed on two isolates, A/Peru/1641/99 and A/Peru/1798/99. Both isolates were distinct from the Bayern/7/95-like viruses circulating in the Americas and closely related to a Beijing/262/95-like variant, A/New Caledonia/20/99. With the exception of travel-related cases, the detection of these isolates represents the first appearance of New Caledonia/20/99-like viruses in the Americas. Since the characterization of these Peru isolates, a number of New Caledonia/20/99-like viruses have been reported worldwide. For the 2000/01 and 2001/02 influenza seasons, the World Health Organization (WHO) has recommended the inclusion of A/New Caledonia/20/99 as the H1N1 vaccine component for both the southern and northern hemispheres

Study protocol for a randomised controlled trial of invasive versus conservative management of primary spontaneous pneumothorax

INTRODUCTION: Current management of primary spontaneous pneumothorax (PSP) is variable, with little evidence from randomised controlled trials to guide treatment. Guidelines emphasise intervention in many patients, which involves chest drain insertion, hospital admission and occasionally surgery. However, there is evidence that conservative management may be effective and safe, and it may also reduce the risk of recurrence. Significant questions remain regarding the optimal initial approach to the management of PSP

Genetic Characterization of H3N2 Influenza Viruses Isolated from Pigs in North America, 1977–1999: Evidence for Wholly Human and Reassortant Virus Genotypes

Since 1998, H3N2 viruses have caused epizootics of respiratory disease in pigs throughout the major swine production regions of the U.S. These outbreaks are remarkable because swine influenza in North America had previously been caused almost exclusively by H1N1 viruses. We sequenced the full-length protein coding regions of all eight RNA segments from four H3N2 viruses that we isolated from pigs in the Midwestern U.S. between March 1998 and March 1999, as well as from H3N2 viruses recovered from a piglet in Canada in January 1997 and from a pig in Colorado in 1977. Phylogenetic analyses demonstrated that the 1977 Colorado and 1997 Ontario isolates are wholly human influenza viruses. However, the viruses isolated since 1998 from pigs in the Midwestern U.S. are reassortant viruses containing hemagglutinin, neuraminidase and PB1 polymerase genes from human influenza viruses, matrix, non-structural and nucleoprotein genes from classical swine viruses, and PA and PB2 polymerase genes from avian viruses. The HA proteins of the Midwestern reassortant swine viruses can be differentiated from those of the 1995 lineage of human H3 viruses by 12 amino acid mutations in HA1. In contrast, the Sw:ONT:97 virus, which did not spread from pig-to-pig, lacks 11 of these changes

A novel method to allow noninvasive, longitudinal imaging of the murine immune system in vivo

In vivo imaging has revolutionized understanding of the spatiotemporal complexity that subserves the generation of successful effector and regulatory immune responses. Until now, invasive surgery has been required for microscopic access to lymph nodes (LNs), making repeated imaging of the same animal impractical and potentially affecting lymphocyte behavior. To allow longitudinal in vivo imaging, we conceived the novel approach of transplanting LNs into the mouse ear pinna. Transplanted LNs maintain the structural and cellular organization of conventional secondary lymphoid organs. They participate in lymphocyte recirculation and exhibit the capacity to receive and respond to local antigenic challenge. The same LN could be repeatedly imaged through time without the requirement for surgical exposure, and the dynamic behavior of the cells within the transplanted LN could be characterized. Crucially, the use of blood vessels as fiducial markers also allowed precise re-registration of the same regions for longitudinal imaging. Thus, we provide the first demonstration of a method for repeated, noninvasive, in vivo imaging of lymphocyte behavior