Specific cell-mediated immunity in fish

This review describes the fish immune system, focusing on specific cell-mediated immunity. Specific in vivo cell-mediated immune responses have been shown by allograft rejection, graft-versus-host reaction (GVHR) and delayed hypersensitivity reaction (DTH). Recent in vitro studies also showed specific cell-mediated cytotoxicity against allogeneic target cells. These in vivo and in vitro experiments strongly suggest the presence of cytotoxic T cells in fishes. Also described are current studies on shark and trout MHC class I polymorphism and function that demonstrate strong similarities between fish and mammals.     

Scanning electron microscopy of vascular corrosion casts and histologic examination of pulmonary microvasculature in dogs with dirofilariosis

OBJECTIVE: To characterize structural changes in pulmonary vessels of dogs with dirofilariosis. ANIMALS: 8 dogs with dirofilariosis and 2 unaffected control dogs. PROCEDURE: Pulmonary artery pressure was measured in affected dogs, and dogs then were euthanatized. Scanning electron microscopy was used to examine vascular corrosion casts of pulmonary vasculature. Tissue sections of pulmonary vasculature were evaluated by use of histologic examination. RESULTS: Pulmonary artery pressure was higher in dogs with severely affected pulmonary vessels. In tissue sections, dilatation, as well as lesions in the tunica intima and proliferative lesions resulting in constriction or obstruction, were frequently observed in branches of the pulmonary artery. Numerous dilated bronchial arteries were observed around affected pulmonary arteries. Hyperplastic venous sphincters were observed in small pulmonary veins and venules. In corrosion casts, affected pulmonary lobar arteries had dilatation, pruning, abnormal tapering, constriction, and obstruction. In small arteries and arterioles, surface structures representing aneurisms and edema were seen. Bronchial arteries were well developed and extremely dilated, and they formed numerous anastomoses with pulmonary arteries at all levels, from the pulmonary trunk to peripheral vessels. Capillaries in the lungs were dilated with little structural change. Small pulmonary veins and venules had irregular annular constrictions that were caused by hyperplastic smooth muscle cells of venous sphincters. CONCLUSIONS AND CLINICAL RELEVANCE: Scanning electron microscopy of microvascular casts delineated links between the bronchial and pulmonary circulations in dogs with dirofilariosis. Results of scanning electron microscopy provided a structural explanation for the development of pulmonary circulatory disturbances and pulmonary hypertension in dogs affected by dirofilariosis.     

Effects of neem (Azadirachta indica) extracts onLeptocorisa chinensis under choice and no-choice conditions

Two extracts from neem (Azadirachta indica A. Juss. (Meliaceae)) seeds, azadirachtin and oil, and a mixture of neem oil and abamectin, were tested on second-instar nymphs of the rice bugLeptocorisa chinensis (Dallas) (Hemiptera: Alydidae). To clarify the effect of spraying coverage on bioefficacy of test materials, experiments were conducted under choice and no-choice conditions in field cages. In a choice test, treatment with the mixture of neem oil and abamectin was most effective in reducing the survival ofL. chinensis, followed by azadirachtin at 60 ppm, 30 ppm and 3% neem oil, whereas all treatments except neem oil caused 100% mortality within 3 weeks in a no-choice test. When second-instar nymphs had choices of treated and untreated plants within a treatment, no differences in yield and sum of dead and stained grains were found between those two choices, indicating that nymphs neither caused significant reduction in yield nor reduced the quality of untreated plants. Regardless of treatment, the difference in overall yield between treated and untreated plants under choice conditions was not statistically significant (P>0.05). Our results indicate that neem-based formulations, used alone or in combination with abamectin, have the potential to be integrated into the existing programs to control the rice bug. http://www.phytoparasitica.org posting Aug. 28, 2005.     

Influence of the chemical composition of kenaf bast and core on the alkaline pulping response

The bast and core of kenaf,Hibiscus cannabinus L., have markedly different chemical components and alkaline cooking responses. The bast had about double the hot-water extractives content and only about half the lignin content of the core. The core contained a large amount of hemicellulose, mostly composed of xylan. The lignin structures of bast and core were also quite different: The former had a significant abundance of syringyl structures. Evidence showed that the bast was much more easily delignified than the core. When the bast and core were cooked together in alkaline condition, the pulp yields at the same kappa number were higher than those of the individual pulpings of bast and core. The bast-core pulping gave a positive effect on the yield of bast pulp in the sodaanthraquinone and kraft pulpings. On the other hand, kenaf was abundant in the hot water extractives. These extractives consumed alkali during cooking to a relatively large extent but acted as a protector of hemicellulose and slightly increased the pulp yields.Part of this paper was presented at the 48th and 49th Annual Meetings of the Japan Wood Research Society, Shizuoka, April 3–5, 1998 and Tokyo, April 3–5, 1999     

Effect of isoflurane anesthesia on hemodynamics following the administration of an angiotensin-converting enzyme inhibitor in cats

The objective of this study was to evaluate the hemodynamics of the anesthetic isoflurane in healthy cats given angiotensin-converting enzyme inhibitor (ACEI). The 7 healthy young cats and 3 old cats were received placebo or enalapril 0.5 mg/kg orally. The change in systolic arterial pressure from the baseline to 30 min postanesthesia in the ACEI group was significantly higher than in the placebo group (mean +/- SD: -39 +/- 13% vs. -17 +/- 12%, respectively). The present study indicated that general anesthesia may induce hypotension after the administration of an ACEI.     

Changes in the levels of circulating plasma free amino acids of carp (Cyprinus carpio) after feeding a protein and an amino acid diet of similar composition

A protein diet containing casein as the sole nitrogen source and an amino acid diet of similar composition (except isolated amino acids represented all of the nitrogen) were fed to triplicate groups of yearling carp. The sequence of appearance of free amino acids in the plasma of carp at 0, 2, 4, 8 and 16 h after feeding the two diets was examined.The circulating levels of all plasma free essential amino acids were in highest concentrations at 4 h after feeding the casein diet, except for arginine which declined slightly from 2 to 4 h. After feeding the amino acid diet, plasma free arginine and lysine were at peak levels at 2 h after feeding, while others peaked by 4 h.Glutamic acid and aspartic acid were detected in very low concentrations in the plasma relative to their levels in the diets, while proline was found in the highest concentrations of all other amino acids.Essential amino acid levels in the plasma were found to be positively correlated with their levels in the diets, while non-essential amino acids were not.     

Global warming impacts of the process to utilize digested slurry from methane fermentation as a fertilizer: Case Study of the Yamada Biomass Plant

Greenhouse gas (GHG) emissions from the process to utilize digested slurry from methane fermentation as a fertilizer were calculated with actual operational data from a methane fermentation plant and the effects were verified by introducing the process into a field system. The results indicated that the total emissions from the utilization of digested slurry as a fertilizer were 8.1 kg-CO₂ eq. per 1 ton of digested slurry and transportation was the major source of GHG emissions, accounting for 67 % of the total emissions. Shortening the transportation distance by using digested slurry in farmlands near the methane fermentation plant is the most effective to reduce GHG emissions. The results also indicated that GHG emissions from the wastewater treatment process for digested slurry were much larger than GHG emissions from the utilization of digested slurry as a fertilizer. In conclusion, CH₄ as an energy source and digested slurry as a fertilizer can be effectively utilized and reduce GHG emissions by introducing the methane fermentation processes to the use of digested slurry as a fertilizer.

     

The effect of 7.2% hypertonic saline solution on m-mode echocardiographic indices in normovolemic dogs

This study investigated whether a small volume of 7.2% hypertonic saline solution (HSS) could affect M-mode echocardiographic indices in dogs. HSS induced significant increase in heart rate, stroke volume and cardiac index, when the fluid infusion was completed (P<0.05). In the HSS group, the left ventricular end-diastolic volume index, as an index of preload, significantly increased (P<0.05), whereas left ventricular end-systolic volume index were not altered. HSS induced slight increases in ejection fraction at end of infusion despite significantly differences were not observed. In conclusion, HSS did not induce a demonstrable effect on M-mode echocardiographic indices of systolic function-enhance cardiac contractility, but it caused preload augmentation that may contribute to an abrupt and transient increase in cardiac output just after HSS infusion.     

Growth response of Tilapia zillii fingerlings fed isocaloric diets with variable protein levels

Six purified casein diets within a range of 21–53% crude protein were fed for 3 weeks to young tilapia (Tilapia zillii) to determine the optimum protein requirement and protein: energy ratio for growth. Growth rate increased proportionally to protein level of the diet to an incorporation rate of about 35%. Beyond this a gradual retardation in growth rate was observed. The diet containing about 30% crude protein with a protein: energy ($\text{P}\text{E}$) ratio of 81, however, appeared to be more efficiently utilized by the fish in terms of protein deposition and energy retention than diets with higher levels of crude protein. These results indicate that Tilapia zillii requires about 35% protein in the diet for optimum growth while 30% for the maximum bodily protein deposition when casein is used as the sole source of protein. All six diets, however, showed an excellent feed conversion. Protein efficiency ratio (PER) decreased with the increase in protein in the diet.