Diversity of movements by individual anadromous coastal cutthroat trout Oncorhynchus clarkii clarkii

Wild, downstream‐migrating cutthroat trout, Oncorhynchus clarkii clarkii, smolts and adults were captured at a weir in Big Beef Creek, Hood Canal, Washington, surgically implanted with acoustic tags and tracked to identify spring and summer movements using stationary receivers in order to test the assumption that the species moves little while in marine waters. Overall, 93–96% migrated from the stream into the east side of the long narrow fjord, where they dispersed north and south along the shoreline. Most O. c. clarkii were detected nearshore within 10 km of the release site, with declining detection rates to 77 km. Over one‐third (36%) crossed c. 2–4 km of deep water to the other side but only one O. c. clarkii left the Hood Canal basin. Movements and behaviour patterns did not differ between smolts and adults but cluster analysis revealed two modes of distribution, here categorized as residents and migrants. Within these categories of overall distribution, a range of finer‐scale behaviour patterns was observed, including sedentary individuals, daily moving between proximate sites and more continuous long‐distance travel. Diel movement patterns varied markedly among individuals but overall activity increased near dawn, peaked around mid‐day and declined but continued at night. These patterns contrast with sympatric and closely related steelhead trout, Oncorhynchus mykiss, providing new insights into the diversity of salmonid behaviour.     

Characterization of a myostatin-like gene from the bay scallop, Argopecten irradians

A complete cDNA was cloned from the bay scallop (Argopecten irradians) that codes for a 382-amino-acid myostatin-like protein (sMSTN). The sMSTN sequence is most similar to mammalian myostatin (MSTN), containing a conserved proteolytic cleavage site (RXXR) and conserved cysteine residues in the C-terminus. Based on quantitative RT-PCR, the sMSTN gene is predominantly expressed in the adductor muscle, with limited expression in other tissues. Using the sMSTN sequence, a Ciona MSTN-like gene was also identified from the Ciona intestinalis genome. These findings indicate that the MSTN gene has been conserved throughout evolution and suggests that MSTN could play a major role in muscle growth and development in invertebrates, as it does in mammals.     

The gene product of the gp78/AMFR ubiquitin E3 ligase cDNA is selectively recognized by the 3F3A antibody within a subdomain of the endoplasmic reticulum

The receptor for the autocrine motility factor/phosphoglucose isomerase cytokine (gp78 or AMFR) has been extensively characterized using the 3F3A monoclonal antibody. Cloning of AMFR identified a seven-transmembrane domain G-protein-coupled receptor ubiquitin E3 ligase whose identity as AMFR was based on prior expression cloning with the 3F3A mAb that generated a truncated sequence. We show here that the gp78/AMFR gene product is indeed recognized by the 3F3A mAb. The FLAG-taggedAMFR immunoprecipitated with an anti-FLAG antibody was recognized by the 3F3A mAb in Western blot analysis and cells transfected with AMFR exhibit increased labeling with the 3F3A mAb. The 3F3A mAb does not however recognize higher molecular weight isoforms of AMFR. 3F3A labeling colocalizes with tagged AMFR in a peripheral ER network but does not recognize FLAG- or GFP-tagged AMFR localized to a perinuclear ER domain that likely corresponds to misfolded forms of the protein retained in the ER. These data indicate that 3F3A antibody binding is highly specific for a subpopulation of AMFR localized to an ER subdomain. Coexpression of AMFR-GFP and a lumenal ER-targeted RFP presented extensive colocalization in living cells andAMFR-GFP is concentrated in a basal ER network morphologically similar to that labeled by the 3F3A mAb in fixed cells. The3F3A anti-AMFR mAb therefore selectively recognizes a subpopulation of expressed AMFR localized to a subdomain of the ER.     

A self-feeding roller bottle for continuous cell culture

The concept of a self-feeding roller bottle that delivers a continuous supply of fresh media to cells in culture, which is mechanically simplistic and works with existing roller apparatuses, is presented here. A conventional roller bottle is partitioned into two chambers; one chamber contains the fresh culture media reservoir, and the other contains the cell culture chamber. A spiroid of tubing inside the fresh media reservoir acts as a pump when the bottle rotates on its horizontal axis, continuously delivering fresh media through an opening in the partition to the cell culture chamber. The modified bottle proved capable of maintaining steady-state cell densities of a hybridoma cell line over the 10-day period tested, although at lower densities than reached during batch operation due to the continuous volume dilution. Steady-state density proved to be controllable by adjusting the perfusion rate, which changes with the rotation rate of the bottle. Specific antibody production rate is as much as 3.7 times the rate in conventional roller bottles operating with intermittent batch feeding.     

Polymeric particles conjugated with a ligand to VCAM-1 exhibit selective, avid, and focal adhesion to sites of atherosclerosis

The increased expression of VCAM-1 on endothelial segments within plaque regions could be used as a target to deliver polymeric drug carriers selectively to sites of atherosclerosis. We probed the hypothesis that polymeric particles conjugated with a ligand for VCAM-1 exhibit selective and avid adhesion to sites of atherosclerosis. Particles made from polystyrene or the biodegradable polymer poly(sebacic acid)-block-polyethylene glycol (PSA-PEG) were conjugated with an antibody to VCAM-1 (alpha-VCAM-1) or IgG (negative control). The particles were injected into the jugular vein of ApoE(-/-) (a murine model of atherosclerosis) or wild type mice and their adhesion to the aorta determined. alpha-VCAM-1 particles exhibited significantly greater adhesion to ApoE(-/-) mouse aorta [32 +/- 5 (mean +/- SEM) particles/mm(2) for polystyrene particles and 31 +/- 7 particles/mm(2) for PSA-PEG particles] compared to the level of adhesion to wild type mouse aorta (18 +/- 1 particles/mm(2) for polystyrene particles and 6 +/- 1 particles/mm(2) for PSA-PEG particles). Within ApoE(-/-) mice, the alpha-VCAM-1 particles exhibited significantly greater adhesion to the aorta (32 +/- 5 particles/mm(2) for polystyrene particles and 31 +/- 7 particles/mm(2) for PSA-PEG particles) compared to the adhesion of IgG particles (1 +/- 1 particles/mm(2) for polystyrene particles and 2 +/- 1 particles/mm(2) for PSA-PEG particles). Detailed analysis of the adhesion revealed that alpha-VCAM-1 particles exhibited focal adhesion to plaque regions, in particular the periphery of the plaques, within the ApoE(-/-) mouse aorta. Combined the data demonstrate that polymeric particles conjugated with a ligand to VCAM-1 exhibit selective, avid and focal adhesion to sites of atherosclerosis providing strong evidence that VCAM-1 ligand bearing polymeric particles could be used for targeting drugs selectively to atherosclerotic tissue.     

Nasal strips do not affect pulmonary gas exchange, anaerobic metabolism, or EIPH in exercising Thoroughbreds.

The present study was carried out to examine whether nasal strip application would improve the exercise-induced arterial hypoxemia and hypercapnia, diminish anaerobic metabolism, and modify the incidence of exercise-induced pulmonary hemorrhage (EIPH) in horses. Two sets of experiments, control and nasal strip experiments, were carried out on seven healthy, sound, exercise-trained Thoroughbred horses in random order, 7 days apart. Simultaneous measurements of core temperature, arterial and mixed venous blood gases/pH, and blood lactate and ammonia concentrations were made at rest, during submaximal and near-maximal exercise, and during recovery. In both treatments, whereas submaximal exercise caused hyperventilation, near-maximal exercise induced significant arterial hypoxemia, desaturation of Hb, hypercapnia, and acidosis. However, O2 content increased significantly with exercise in both treatments, while the mixed venous blood O2 content decreased as O2 extraction increased. In both treatments, plasma ammonia and blood lactate concentrations increased significantly with exercise. Statistically significant differences between the control and the nasal strip experiments could not be discerned, however. Also, all horses experienced EIPH in both treatments. Thus our data indicated that application of an external nasal dilator strip neither improved the exercise-induced arterial hypoxemia and hypercapnia nor diminished anaerobic metabolism or the incidence of EIPH in Thoroughbred horses performing strenuous exercise.     

Changes in Muscle Volume and Composition After Treatment of Hip Dysplasia with Periacetabular Osteotomy

BackgroundPeriacetabular osteotomy (PAO) is a common treatment for pre-arthritic hip dysplasia in young adults. The purpose of this study was to better understand changes in muscle volume and composition after PAO visualized using magnetic resonance imaging (MRI).MethodsA prospectively collected series of individuals that underwent PAO for hip dysplasia were reviewed to identify subjects with pre- and postoperative MRI. In our practice, MRI was obtained preoperatively and greater than 6 months after PAO for persistent hip pain. MRI sequences were selected to optimize visualization of the muscle volume, fatty infiltration, and hip joint cartilage. MRI images were selected at predetermined bony landmarks and analyzed using 3D Slicer (©2021, www.slicer.org) software to measure muscle diameter and calculate muscle cross-sectional area (CSA) in 17 individual muscles surrounding the hip. Muscle atrophy was graded using the Goutallier classification for fatty infiltration and acetabular cartilage condition was graded using the Outerbridge classification. We compared pre- and postoperative muscle area and composition as well as cartilage for each case.ResultsA series of six female patients met our inclusion criteria. Mean age was 26 years at time of surgery. All cases had MRI sequences adequate for muscle volume measurements. Fatty infiltration and cartilage changes were recorded in four subjects with appropriate MRI sequences. Separating muscle groups, external rotators underwent the largest volume increase. Hip flexors demonstrated mild volume decrease. CSA change among external rotators averaged +12%, hip flexors -9.3%, and hip abductors -9.2% after PAO. All muscles had either the same or increased fatty infiltration after surgery, with gluteus medius and iliacus undergoing the most average increase. Similarly, cartilage condition worsened by a small margin in this series.ConclusionOur results provide preliminary indication that PAO may have noticeable effects on muscle characteristics and cartilage in the early postoperative period. This was a limited case series of subjects with adequate pre- and post-operative MRI imaging.Level of Evidence: IV