Arterial supply to the rat colon

Rats are often used as animal models in studies such as on intestinal transplantation and anastomosis healing, which require colectomy. Although detailed information regarding arterial supply is important to establish accurate and reproducible experimental procedures, this has not been studied in the rat colon. Therefore, we analysed the detailed arterial distribution pattern and its individual variations in the colon of 34 rats. The rat colon received colic branches of the ileocolic artery, and the right, middle and left colic arteries. The single left colic artery constantly arose from the caudal mesenteric artery and was distributed to the descending colon, whereas the others showed variations in number and distribution. The ileocolic artery gave rise to one (12%) or two (88%) colic branches supplying the proximal ascending colon, and these branches formed rich, mesh-like anastomoses along the initial portion of the ascending colon. One (74%) or two (26%) right colic arteries originated from the cranial mesenteric artery and supplied the ascending colon and right colic flexure. Moreover, one (38%), two (56%) or three (6%) middle colic arteries emerged from the cranial mesenteric artery and were distributed to the transverse colon, left colic flexure and proximal descending colon. In total, we categorized the individual variations in arterial branching and anastomosis into 11 patterns. Arterial supply to the rat colon showed a specific pattern and frequent individual variations. These findings thus provide essential information for establishing reproducible models of rat colic surgery.     

Cadmium detoxification effect of Chinese parsley Coriandrum sativum in liver and kidney of rainbow trout Oncorhynchus mykiss

Although fish feed supplemented with Chinese parsley (CP), Coriandrum sativum, does not affect the health of rainbow trout Oncorhynchus mykiss, it has the remarkable effect of reducing the uptake of Cd (12–17% compared with controls without CP). Here, we measured the change in the amount of metallothionein (MT) in the liver and kidney using gel permeation chromatography-high-performance liquid chromatography (TSK GEL SW 3000 column). The increase in MT content over time in the Cd-fed groups corresponded to the change in Cd accumulation. Gel permeation was performed with soluble fractions from the fish liver and kidney, and changes in the Cd, Cu, and Zn concentrations over time for each fraction, and the relationship between the form of Cd that accumulated in tissues and its toxicity were measured. A nontoxic MT fraction of 7,000 Da and a high-molecular-weight fraction of approximately 60,000 Da were isolated from the soluble fractions. The induction of nontoxic MT–Cd was higher in the CP-supplemented groups than in the control groups. The synergetic actions of several compounds in CP may contribute to bind MT, thereby preventing accumulation of harmful heavy metals and essential metals in fish.     

Use of an optical biosensor with a silicone-immobilized enzyme to determine plasma total cholesterol concentrations in fish

Decreased plasma total cholesterol concentrations are a useful indicator in fish of reduced resistance to bacterial infection. Taking advantage of the hydrophobic properties of silicone rubber, we developed an optical enzyme sensor system for measuring plasma cholesterol concentrations in fish. The system was constructed using an immobilized enzyme membrane, optical oxygen probe, flow system, and personal computer. The enzyme membrane was prepared from cholesterol esterase, cholesterol oxidase, and silicone rubber. The calibration curves were linear in the range of 55–85 mg dl⁻¹ for yellowtail and 20–90 mg dl⁻¹ for rainbow trout. Assays could be completed within 3 min, and the sensor response was stabilized by the hydrophobic properties of silicone rubber. Storage of immobilized enzyme membranes at 5°C permitted stable measurements for 58 days. The sensor system was applied to determine plasma total cholesterol concentrations in fish. Good correlations were obtained between results obtained using the sensor and results obtained using conventional methods (correlation coefficients: yellowtail 0.9751, rainbow trout 0.9947). Our method required much less time than conventional cholesterol assays and can be used economically for continuous determination of plasma total cholesterol in fish.     

Rapid enumeration of bacteria grown on surimi-based products by flow cytometry

ABSTRACT: A rapid method to enumerate bacteria adhered on a surimi-based product (kamaboko) by flow cytometry (FCM) is described. To remove Escherichia coli cells from the surface of kamaboko, ultrasonic energy was used. Almost all cells can be removed from kamaboko in 3 min with ultrasonic treatment. Because the sample might contain various non-bacterial particles such as food additives and debris of products, propidium iodide was used to discriminate bacterial cells from non-bacterial particles. Fluorescence scattergrams could distinguish bacteria from the particles, and the FCM method could be used to enumerate bacteria adhered on the surface of kamaboko during storage. Cell numbers determined by FCM paralleled well with those measured using a traditional colony counting method in the range of 10⁴–10⁸ cells/g. The FCM assay could enumerate cells within 1 min and the total assay time, including sample preparation, was less than 30 min.     

Effect of cadmium binding form on rabbit aminolevulinate dehydratase in high molecular weight fraction of rainbow trout liver

Enzyme inhibition owing to cadmium (Cd) accumulation in the soluble high molecular weight fraction (HMF) of the liver from rainbow trout was investigated by measuring the inhibition of aminolevulinate dehydratase (ALAD). Factors affecting ALAD, which reacts specifically to metal, were examined before measuring ALAD activity. Although enzyme inhibition by Cd in the HMF was confirmed in the excretion 2 (E2) group fed Chinese parsley (CP), it was weaker than that in the excretion 1 (E1, control) group, probably due to the chelation of Cd by some substances contained in CP. Based on the absorption spectrum, the proportion of Cd bound to cysteine thiol radicals in the HMF of the E2 group was greater than that of E1. The HMF might detoxify harmful metals to some extent because it contains relatively higher levels of cysteine residues than metallothionein (MT) and shows comparatively weak enzyme inhibition. The results of the present study demonstrated that, in addition to MT, HMF is involved in the detoxification of harmful heavy metals in fish.     

Branching patterns of the adrenal arteries in the degu (Octodon degus)

The degu has drawn increasing attention for use as an experimental animal in stress response studies due to its physiological features, such as diurnality and seasonal breeding, which differ from conventional laboratory rodents. Stress response is elicited by steroid hormones secreted by the adrenal gland, whose functions are controlled by pituitary hormones reaching through the adrenal arteries. However, knowledge of the arterial anatomy of the degu adrenal gland remains insufficient. To address this issue, we observed adrenal arteries in 20 male degus injected with red-colored latex. Adrenal arterial branching patterns were classified into Types 1–4, which respectively have 1 to 4 parent arteries that give rise to the adrenal arteries. Based on the combination of the parent arteries, Types 2 and 3 were categorized into subtypes a to c, while Type 4 was categorized into subtypes a and b. On the left side, Type 2 (45%) and Type 3 (45%) were predominant, whereas Type 1 (5%) and Type 4 (5%) were infrequent. On the right side, Type 2 (50%) and Type 3 (45%) were predominant, whereas Type 4 (5%) was infrequent. Type 1 was not present. There were 0 to 4 cranial, 1 to 4 middle and 1 to 4 caudal adrenal arteries, with the total number varying from 2 to 9. The present observation provides knowledge of comparative anatomical features of the degu adrenal arteries, which can serve as an anatomical basis for comparative endocrinological studies.     

Removal of cadmium from scallop processing waste by washing with weak acid solution and utilization of useful constituents for organic fertilizer manufacturing

ABSTRACT:   Hepatopancreases were washed four times with 2% acetic acid solution. In both the washed hepatopancreases and the supernatant of the washing solution, the residual cadmium (Cd) concentration was in accordance with the required standard for organic fertilizers. Hepatopancreases do not naturally contain high levels of nitrogen, but they do contain several amino acids which are useful for cultivation, and these were retained during the washing process. Although the condensed precipitate of the washing solution contained a considerable amount of Cd, Cd elution levels at the time of final disposal met judgment standard for special management industrial waste as a result of kneading and immobilizing with chelating adsorbent for treatment of contaminated soil. The volume of the precipitate of the washing solution was one-fifth of the original hepatopancreas, and the solid waste was suitable for burial at a final disposal site without further treatment.     

Isolation of a viable but non-culturable suppression mutant of Vibrio vulnificus: role of antioxidant enzymes in surviving stationary phase and low temperatures

ABSTRACT:   The viable but non-culturable (VBNC) suppression mutant was isolated. Suppression subtractive hybridization was used to identify differentially expressed genes among cDNA of the VBNC suppression mutant and the wild-type strain. RpoS-dependent catalase was highly expressed from the VBNC suppression mutant during oxidative stress in the stationary phase and at low temperatures. In experiments of H₂O₂ sensitivity, the VBNC suppression mutant showed a peroxide-resistant phenotype in the stationary phase and at low temperatures. These results suggest that VBNC suppression mutant cells use catalase for protection against oxidative stress in the stationary phase and at low temperatures.     

Effect of chinese parsley Coriandrum sativum and chitosan on inhibiting the accumulation of cadmium in cultured rainbow trout Oncorhynchus mykiss

ABSTRACT:   Toxic heavy metals such as cadmium (Cd) accumulate in cultured fish from solid-form feed mixtures. In this paper, two natural ingredients, supposed to inhibit accumulation of heavy metals in the fish body, were investigated to develop a functional feed mixture for healthy fish. Three test diets: (i) ♯1, regular diet as negative control; (ii) ♯2, ♯1 + 2% lyophilized Chinese parsley Coriandrum sativum (CP); and (iii) ♯3, ♯1 + 3% chitosan (CT), were each fed to 50 rainbow trout Oncorhynchus mykiss once a day, at the constant rate of 1.0–1.2% of body weight for 12 weeks. No undesirable effect on fish growth was observed by an addition of either CP or CT to regular feed. Then, 10 mg Cd was added to 1 kg each of the three test diets and they were named as: (i) ♯4, ♯1 + Cd; (ii) ♯5, ♯2 + Cd; and (iii) ♯6, ♯3 + Cd, respectively. The fish given positive a control feed (diet ♯4) for 3 weeks accumulated Cd in the liver and kidney at approximately 0.52 mg/kg. However, Cd in ordinary muscle was found to be just above the detection limit. Upon accumulation of Cd, three groups of 50 fish were each fed test diets ♯4, ♯5, and ♯6 for 12 weeks at the same feed rate described above. The concentrations of Cd accumulated in the liver, kidney, and ordinary muscle of the fish were measured every 3 weeks. Contrary to the positive control fish fed diet ♯4, those fish fed test diets ♯5 and ♯6 accumulated 20–30% and 25–40% less Cd in the liver, respectively. Test diets were a little less effective for inhibition of Cd uptake in the kidney than that observed in the liver. These results suggest that addition of CP or CT to fish feed might be used to decrease toxic heavy metal accumulation in fish.