Seasonal changes in proteolytic enzymes of yellowtail Seriola quinqueradiata (Temminck & Schlegel; Carangidae) fed extruded diets containing different protein and energy levels

Seasonal variations in pepsin, trypsin and chymotrypsin activities and protein digestibility were studied in yellowtails (Seriola quinqueradiata) reared for 1 year with extruded diets containing different levels of protein. Trypsin and chymotrypsin storage levels in the digestive tissues of starved fish were affected by seasonal changes in water temperature. Actual digestion activities of trypsin and chymotrypsin were low at lower water temperatures, but pepsin activity in the stomach tissue was not affected by low temperatures. On the other hand, trypsin and chymotrypsin activities in the intestinal contents were higher during lower water temperature months, while pepsin activity in the stomach contents was low at lower water temperatures. Apparent protein digestibility (APD) did not differ among the dietary treatments in the higher water temperature months, while in colder months it was higher in fish fed diet 1 than in fish fed diets 2 and 3. The APD values reflected pepsin activity in the stomach contents in all sampling months. Therefore, lower APD in colder months seems to be attributed to lower protease activity in the gastric digesta, implying that enhanced pepsin secretion from the stomach tissue might improve protein digestibility and growth performance in yellowtails during winter.     

Relationship of climatic conditions to fecal corticosterone levels of captive cheetahs reared in Japan

To assess the stress level of cheetahs reared in Japan and to identify the prime components of the climatic conditions that affect their thermal stress, fecal corticosterone was monitored for 8 months from May to the following January. A total of 203 fecal samples were gathered in the morning from seven adult cheetahs that were kept at a zoological garden in Wakayama, Japan. Cheetahs were on exhibit singly or together with a harmonious conspecific during the day, but housed singly at night. Although the monthly fluctuation in corticosterone concentrations was not significant, the concentrations were relatively low during the summer season. Individual differences among cheetahs and the interaction effect between individual and month on the corticosterone concentrations were significant. Whereas the corticosterone concentrations negatively correlated with air temperature, they were positively correlated with the amount of rainfall. The highest air temperature and the amount of rainfall were extracted as the prime factors affecting corticosterone concentrations. These results suggest that cheetahs reared in Japan are somewhat subjected to thermal stress, particularly on cooler and/or rainy days.     

An economic value for ecosystem-based disaster risk reduction using paddy fields in the kasumitei open levee system

Paddy and Water Environment - In this article, we examined the value of the traditional Japanese flood control measure that uses a discontinuous levee (kasumitei). By avoiding the use of...     

Changes in blastogenic responses of lymphocytes and delayed type hypersensitivity responses after vaccination in dogs.

To clarify the immunologic effects of vaccination in dogs, we monitored total leukocyte and lymphocyte counts, humoral antibody responses, blastogenic responses of lymphocyte, and delayed type hypersensitivity (DTH) responses after vaccination. Mixed vaccines were administered on day 0 except for canine parvovirus (CPV) vaccine which was readministered on day 21. The puppy and adult dogs had a significant decrease in leukocyte and lymphocyte counts on day 7. The puppies showed a significant increase in the blastogenesis of lymphocytes after each vaccination, whereas the adult dogs had no significant changes. However, the adult dogs were divided into two groups, high responders and low responders in blastogenesis of lymphocytes. The dogs with higher or lower response in SI values on day 0 tended to show decrease or increase after the first vaccination, respectively. Since almost all dogs developed high titers of humoral antibody, it is considered that vaccination acts in an immunomodulative fashion. DTH responses to phytohemagglutinin (PHA) and CPV vaccine monitored at 0, 3, and 8 weeks after the first vaccination produced strong reactions, in particular those to CPV vaccine rose significantly after vaccination and maintained the higher responses for at least 2 months. These results suggest that DTH responses to PHA and CPV vaccine are helpful to monitoring non-specific and specific immune functions in vivo, therefore, DTH could be used as simple and rapid immunologic tests in canine practice.     

A comparative study of the effects of glycerol and hydroxyethyl starch in canine red blood cell cryopreservation

Hydroxyethyl starch (HES) is a nonpenetrating extracellular cryoprotectant. In contrast to glycerol, it does not require labor-intensive removal from thawed red blood cells (RBCs) prior to transfusion. In this study, we compared glycerol and HES, and assessed HES as a substitute for glycerol in cryopreserved canine RBCs. The RBCs were preserved for 2 months in liquid nitrogen using a 20% (w/v) glycerol solution, and variable concentrations of HES solution. We evaluated the two cryoprotectants by the percentage of post-thaw hemolysis from the total free hemoglobin, saline stability, osmotic fragility, and by observing the erythrocyte morphology using a scanning electron microscope after thawing. The optimal concentration of HES was 12.5% (w/v) for the cryopreservation of canine RBCs. The thaw hemolysis, saline stability, and osmotic fragility index were 25.6 +/- 4.7%, 87.8 +/- 6.9%, and 0.445 +/- 0.024% NaCl respectively. These parameters resemble the results of RBCs frozen in a 20% (w/v) glycerol solution, which are 24.7 +/- 5.2%, 99.2 +/- 0.1%, and 0.485 +/- 0.023% NaCl respectively. From a morphological point of view, 12.5% (w/v) HES showed the best cryoprotection of RBCs compared to the other concentrations of HES. These results suggest that HES could be a possible substitute for glycerol for the cryopreservation of canine RBCs.     

Distribution of protein disulfide isomerase during maturation of pig oocytes

Oocyte maturation in mammals is characterized by a dramatic reorganization of the endoplasmic reticulum (ER). In mice, the ER forms accumulations in the germinal vesicle (GV) stage and distinctive cortical clusters in metaphase II (MII) of the oocyte. Multiple evidence suggests that this ER distribution is important in preparing the oocyte for Ca²⁺ oscillations, which trigger oocyte activation at fertilization. In this study, we investigated the time course and illustrated the possible functional role of ER distribution during maturation of porcine oocytes by immunostaining with protein disulfide isomerase (PDI). PDI forms clusters in the cytoplasm of oocytes. After immunostaining, PDI clusters were identified throughout the cytoplasm from the GV to metaphase I (MI) stage; however, at the MII stage, the PDI formed large clusters (1–2 µm) in the animal pole around the first polar body. PDI distribution was prevented by bacitracin, a PDI inhibitor. Our experiments indicated that, during porcine oocyte maturation, PDI undergoes a dramatic reorganization. This characteristic distribution is different from that in the mouse oocyte. Moreover, our study suggested that formation of PDI clusters in the animal pole is a specific characteristic of matured porcine oocytes.     

Bacterial Pleuritis with Thickened Mesothelial Hyperplasia in a Young Beagle Dog

A five-month-old male beagle dog suddenly became moribund. Bloody fluid accumulated in the thoracic and abdominal cavities, and soft yellow flecks were floating in the thoracic fluid. The mediastinum and pericardium became dark reddish with villous thickening. Other parietal and pulmonary pleurae were rough, and the organs adhered to each other. Histologically, most mediastinal pleura formed papillary projections covered by a single layer of mesothelial cells. Many macrophages and neutrophils infiltrated the submesothelial connective tissue. At the mediastinum adjacent to the pericardium, cuboidal mesothelial cells proliferated solidly and formed a thick surface stratum. The flecks consisted of gram-negative filamentous or small bacillary (coccoid) bacteria. In the right posterior lobe of the lung, neutrophilic infiltration and a large encapsulated abscess including a bacterial colony were present. We diagnosed this case as “bacterial pleuritis with thickened mesothelial hyperplasia”. The cause of the pleuritis might be a chronic pleural infection spread via the lung abscess.