Hypoxic conditions induce centrum defects in red sea bream Pagrus major (Temminck and Schlegel)

A previous study elucidated that an extreme hypoxia during somitogenesis induced the most frequent skeletal malformation centrum defects in red sea bream (RSB), Pagrus major. In this study, details of the hypoxic conditions to induce them in RSB, dissolved oxygen (DO) concentration and exposure time to hypoxia, were investigated. Fertilized eggs were exposed to seawater of six DO concentrations (0%, 10%, 25%, 50%, 75% and 100% of saturation) for seven different periods (5, 10, 30, 60, 120, 240 and 360 min) during somitogenesis. Somitic disturbances in newly hatched larvae were induced by exposure to 0% and 10% DO concentration for 10 and 120 min and longer respectively. Rearing eggs exposed to hypoxic condition of 10% DO for 240 min for 40 days post‐hatch showed that the location and the frequency of somitic disturbances in larvae and centrum defects in juveniles were significantly correlated (P<0.01). Dissolved oxygen concentration of the interstitial water in the egg high density layer formed at the water surface in a stationary state abruptly decreased to 3.7% within 7 min. Centrum defect induction by exposure of eggs to extreme low DO concentrations for a short period, which is the probable situation in the practical juvenile production, suggests that careful maintenance of DO concentration is important in the incubating water of fertilized eggs during egg sorting and transportation, where eggs are made into a pile and undergo hypoxia, for the prevention of centrum defects.     

Oxygen deficiency during somitogenesis causes centrum defects in red sea bream, Pagrus major (Temminck et Schlegel)

Vertebral deformities in red sea bream, Pagrus major, remain serious obstacles to the improvement of seedling quality for its aquaculture. However, the causalities of the deformities remain unclear and prevention methods have not yet been established. In this paper, oxygen deficiency during somitogenesis was demonstrated to cause centrum defects (formerly called fused vertebrae in many cases), which are the major vertebral deformity in cultured red sea bream. An induction experiment of centrum defects was conducted by placing fertilized red sea bream eggs under low dissolved oxygen conditions (10.3–16.6%). The low oxygen treatment was carried out for five different developmental stages of embryo: two‐cell stage to blastula stage; gastrula stage; three to 10 somites stage; 11–17 somites stage and 18–24 somites stage. Oxygen deficiency during somitogenesis induced a high incidence of centrum defects. In contrast, it hardly induced centrum defects during the other stages. The dissolved oxygen concentration in the rearing water should be carefully regulated for fertilized eggs, especially during somitogenesis to reduce the incidence of vertebral deformities in the red sea bream.     

Effect of Artemia enrichment on the growth and survival of Pacific bluefin tuna Thunnus orientalis (Temminck & Schlegel) larvae

This study was carried out to investigate the suitability of Artemia enriched with docosahexaenoic acid (DHA) and choline as live food on the growth and survival rate of the Pacific bluefin tuna (PBT; Thunnus orientalis) larvae. The PBT larvae were fed either Artemia enriched with oleic acid (Diet 1), DHA (Diet 2), DHA+choline 1.0 mg L^?1 (Diet 3) and DHA+choline 2.0 mg L^?1 (Diet 4) or striped knifejaw larvae (Diet 5, reference diet), in duplicate for 12 days. Enrichment of Artemia with DHA significantly increased the DHA levels to 13.9, 13.8 and 12.5 mg g^?1 on a dry matter basis in Diets 2, 3 and 4 respectively; however, the levels were significantly lower than the reference diet (26.9 mg g^?1 dry matter basis; Diet 5). Although growth and survival rate were significantly improved by the enrichment of Artemia with DHA and choline, the improvement was negligible compared with the enhanced growth and survival rate of the fish larvae‐fed group (P<0.05). The results demonstrated that enriched Artemia does not seem to be the right choice to feed the PBT larvae perhaps because of the difficulties in achieving the correct balance of fatty acid with higher DHA/EPA from Artemia nauplii.     

EFFECT AND SAFETY OF MEGLUMINE IOTROXATE FOR CHOLANGIOCYSTOGRAPHY IN NORMAL CATS

The biliary opacification characteristics and toxicity of meglumine iotroxate (Biliscopin) were studied in twenty-three normal cats. Intravenous administraion of 72 mg/kg of Biliscorpin resulted in opacification of the gallbladder and bile duct 20 minutes after administration. Licking and vomiting appeared in ten of twelve cats immediately after administration. These side-effects were abolished by administration of an anti-histaminic agent. Slight elevation in ALT or AST was detected 24 hours after administration of Biliscopin. These findings suggest that Biliscopin can be used safely in the cat.     

An evaluation of radiographic hepatic size in dogs with portosystemic shunt

Radiographically, the hepatic sizes of portosystemic shunt (PSS) cases were evaluated. In this study the hepatic area was compared in PSS and non-PSS dogs by utilizing the right lateral radiography. The top three breeds of PSS dogs of Maltese, Shih Tzu and Yorkshire Terrier, were included and these dogs had a significantly smaller hepatic area ratio of 46.37 +/- 0.63%, 61.76 +/- 0.78% and 41.59 +/- 0.23% respectively (p<0.05) and the average overall hepatic area in the 3 dog breeds was 47.75 +/- 0.40%.     

Kinetics of glutamate and gamma-aminobutyric acid in cerebrospinal fluid in a canine model of complex partial status epilepticus induced by kainic acid

An imbalance of excitatory and inhibitory transmitters in the brain has been suggested to cause epileptic seizures. In this study, we investigated the kinetics of glutamate (GLU) and gamma-aminobutyric acid (GABA) in cerebrospinal fluid (CSF-GLU and CSF-GABA, respectively) using a high performance liquid chromatography (HPLC) in a canine model of complex partial status epilepticus (CPSE) induced by the microinjection of kainic acid (KA) into the unilateral amygdala. During the acute phase (3, 6, 12 and 48 hr after the onset of CPSE), CSF-GLU was significantly increased, while CSF-GABA was decreased, although not significantly. In the chronic phase, both CSF-GLU and CSF-GABA were significantly lower than normal at 72 hr after the onset of CPSE, and their levels returned to normal at 2 months. Results of the present study demonstrate that CSF-GLU is gradually increased in relation with seizure severity, and suggested the possibility that CSF-GABA was consistently decreased during CPSE induced by KA in dogs.     

Priming abiotic factors for optimal hybrid Cymbidium (Orchidaceae) PLB and callus induction,plantlet formation,and their subsequent cytogenetic stability analysis

Abiotic factors affect the induction of PLBs and callus in hybrid Cymbidium Twilight Moon ‘Day Light’. The initiation and proliferation of new PLBs and callus could be achieved on NAA and kinetin, supplemented at 0.1 mg l⁻¹ each, respectively, both within 45–60 days. Bacto agar was found to be the most suitable solidifying agent for PLB induction, although a higher shoot fresh weight was obtained on Gelrite; a pH 5.3 was optimal while pH 4.5 caused 100% explant necrosis; coconut water, when supplied at 10–20% (v/v) resulted in a significant increase in the number of PLBs formed per PLB segment (23.1 versus 14.6 in controls) while a massive (almost four-fold) increase in fresh top weight occurred when PLB explants were placed in liquid culture, as a result of hyperhydricity; Fe-EDTA (1 mg l⁻¹) and activated charcoal (1 g l⁻¹) stimulated total fresh weight and PLB formation in the presence of PGRs; PLB formation decreased but total fresh shoot weight increased with the addition of niacin or myo-inositol, both vitamins. Dark-grown PLB-induced plants were etiolated and had longer internodes and higher fresh weight than light-grown control plants at 45 μmol m⁻² s⁻¹; at 15 μmol m⁻² s⁻¹ shoots were slightly etiolated, fragile, and PLB formation was scarce. RAPD and mtDNA analysis of all resultant PLBs, callus or plants showed them to be genetically identical, with comparable chlorophyll contents. Despite the detection of cytological variation between different plant parts, little variation resulted from abiotic factor treatment.     

Cerebellar myxoid type meningioma in a Shih Tzu dog

A 6-year and 9 month-old, male, Shih Tzu dog showed ataxia and trembling. By MRI examination, a mass (1 cm) was found in the right cerebellum. As the dog did not respond to radiation therapy, and showed a rise of intracranial pressure, he was euthanized. The cerebellar mass was soft and hemorrhagic. Histologically, the mass contained vimentin-positive spindle- or polyhedral-shaped cells arranged in a cord-like pattern. Mucinous materials were observed in the intercellular spaces. Ultrastructural examination revealed cell processes, microtubule-like structures and desmosomes. The case was diagnosed as myxoid type meningioma.     

Identification of an antihypertensive peptide derived from chicken bone extract

A novel angiotensin‐converting enzyme (ACE) inhibitory peptide was isolated and purified from chicken bone extract by enzymatic digestion. The peptide was defined as an ACE inhibitor, and it demonstrated antihypertensive activity following oral administration to spontaneously hypertensive rats (SHRs). The results of this study suggest that peptides derived from an extract of chicken bones, administered orally, have the ability to reduce the blood pressure of SHRs significantly over a short period of time (3 h). Moreover, the blood pressure then remains low for 3 h. This peptide derived from chicken bones may therefore have great value as a short‐term remedy for chronic conditions such as high blood pressure. The amino acid sequence of the peptide was YYRA (Tyr‐Tyr‐Arg‐Ala), which was the origin of the Ig heavy chain V region (27–30 position). The IC₅₀ value of its synthetic peptide was 33.9 μg/mL. We suggest that the ACE inhibitory and antihypertensive peptides derived from chicken bone extract may contribute to develop physiologically functional foods or improve food functionality.