Magnetic resonance imaging of canine mast cell tumors

Mast cell tumors (MCT) are the most common cutaneous tumors in dogs. Our purpose was to describe the magnetic resonance (MR) imaging characteristics of cutaneous MCT and to identify imaging characteristics that allow differentiation of metastatic from normal lymph nodes. Eight dogs with a total of nineMCT were imaged as were their presumed draining and associated contralateral lymph nodes. The signal intensity of tumors and lymph nodes was compared to adjacent musculature. On T2-W images, 7/9 MCT were hyperintense to muscle and 2/9 were isointense. On T1-W images, 8/9 MCT were isointense and 1/9 were mildly hypointense. All tumors were strongly contrast enhancing; 5/9 were homogeneous and 4/9 heterogeneous in their enhancement patterns. Six lymph node pairs were included in the evaluation (five sentinel lymph nodes with metastases, one without, and six contralateral lymph nodes). Metastatic lymph nodes were significantly larger than their contralateral lymph nodes (P = 0.039). All lymph nodes were isointense on T1-W images and hyperintense on T2-W images. 5/5 metastatic and 2/7 normal lymph nodes were heterogeneously T2-hyperintense. All lymph nodes were moderately to strongly contrast enhancing. 4/5 metastatic and 2/7 normal lymph nodes had heterogeneous enhancement patterns. While heterogeneity was more common in metastatic than in normal lymph nodes, this difference was not significant (P = 0.058 for T2-W images; P = 0.234 for postcontrast images). MR imaging may be useful in the presurgical evaluation and clinical staging of cutaneous MCT.     

MAGNETIC RESONANCE IMAGING OF THE CANINE ABDOMEN: EFFECT OF PULSE SEQUENCE ON DIAGNOSTIC QUALITY

Motion artifact is an important limiting factor for abdominal magnetic resonance imaging (MRI) in veterinary patients. The purpose of this study was to determine the effects of pulse sequence on abdominal MRI diagnostic quality in dogs. Ten normal dogs were each scanned using 16 MRI pulse sequences. Sequences included breath‐holding sequences, respiratory navigation sequences, and traditional spin‐echo sequences. Four observers independently scored diagnostic quality for each sequence based on the appearance of specific organs, overall diagnostic quality, and degree of artifactual interference. Signal‐to‐noise ratio and contrast‐to‐noise ratio were also calculated for each sequence. The sequence with the highest overall mean diagnostic quality score was the dorsal T2 turbo spin echo (TSE) with fat saturation and breath‐holding. The sequence with the lowest mean diagnostic quality score was the dorsal T2 fast spin echo. The sequence with the highest signal‐to‐noise ratio for all evaluated organs was the sagittal T1 spin echo. Signal‐to‐noise and contrast‐to‐noise ratios did not correlate with subjective assessment of overall diagnostic quality for the majority of the sequences evaluated (P < 0.05). The three sequences considered to have the highest diagnostic quality for the cranial abdomen were the dorsal T2 TSE with fat saturation and breath‐hold, transverse T1 turbo fast low‐angle shot gradient echo with breath‐hold, and dorsal T2 half‐Fourier acquisition single shot TSE with respiratory navigation. These sequences had short acquisition times, yielded studies of similar diagnostic quality, provided complementary information, and are therefore recommended for routine canine abdominal MRI protocols.     

大豆粕在海水虾类饲料上的应用（一）

近年来虾类每年的产量大约有一百万吨,而全世界养殖的虾类有20多种,其中产量最多的虾类主要有8种（表一）。在东半球是以生长快速的斑节对虾（Penaeus monodon）为主,而在西半球则以白对虾（Litopenaeus vannamei）的产量占居首位。     

Effect of Dietary Lecithin in Combination with Casein or Crab Protein on Cholesterol Uptake and Transport in the Lobster Homarus americanus

Purified diets, formulated with and without lecithin and containing either casein or a protein isolated from whole crab, were fed to juvenile lobsters. In order to examine the role of these dietary factors on cholesterol uptake and transport, levels of cholesterol were determined in serum, lipo-protein fractions, tissues, and feces of juvenile lobsters fed the experimental diets. Lobsters fed diets supplemented with lecithin had significantly higher levels of serum and lipoprotein cholesterol than lobsters fed diets without supplemental lecithin regardless of the proteins used. Levels of fecal total cholesterol also were generally greater for lobsters fed lecithin-supplemented diets. Tissue, serum, and fecal levels of intubated radiolabeled cholesterol, however, were not significantly different among diet groups, and apoprotein electrophoretic mobility was not affected by the choice of dietary protein.     

SUCCESSFUL ARTIFICIAL DIETS FOR THE CULTURE OF JUVENILE LOBSTERS

Purified and semipurified diets yielding good growth and survival of lobsters (Homarus americanus) have been developed. Growth of animals fed the semipurified diet for 18 months at 20±1°C indicates that market size (.5 kg) could be attained within 2.5 years. The semipurified diet contains 53% (dry weight) protein using casein, shrimp meal, gluten, and egg white as different protein sources. Substitution of these particular sources of protein with soy protein, shrimp protein, a soy protein-shrimp meal combination, or bacterial cell protein caused significant reductions in growth. Similar growth can be achieved when the protein level of the semipurified diet is reduced to 30.5%. It appears that if specific protein and energy requirements are met, diets containing low protein levels can be nutritionally adequate for optimal growth, thereby increasing the possibility of cost-effective diets for intensive lobster culture.