Search for an index for the taste of Japanese Black cattle beef by panel testing and chemical composition analysis

To search for an index for chemical composition related to superior taste in Japanese Black beef, we conducted panel tests and analyzed the chemical composition of seven beef brands. Thirty‐five sirloin beefs from five heifers were used in this study, sold under seven beef brands graded as more than A4 on the Japanese Meat Grade scale. The chemical composition analyses assessed both raw and roasted meat, the latter of which was roasted under the same conditions as those used for the panel test. Results of the panel test and chemical composition analyses revealed that fatty acid composition, sugar content, adenosine triphosphage (ATP)‐related compounds, amino acid composition and odor composition in the sirloin meat differed among beef brands. Furthermore, the correlations of chemical compositions between roasted and raw meat were significantly high. Sugar content and ATP‐related compounds in roasted meat were significantly correlated with the item ‘overall evaluation’ of the panel test. ATP‐related compounds, such as inosinic acid, carnosine and taurine, in roasted and raw meat were correlated significantly with the item ‘umami intensity’ of the panel test. These results suggest that the composition of these components is important for an index related to the overall evaluation of beef.     

Stimulation of Adrenal Chromaffin Cell Proliferation by Hypercalcemia Induced by Intravenous Infusion of Calcium Gluconate in Rats

Increased incidence of adrenal pheochromocytoma is frequently encountered in rat carcinogenicity studies. In some of the studies, the finding is judged to be due to a rat-specific mechanism of carcinogenesis caused by a disturbance of calcium homeostasis. However, direct evidence that the proliferation of chromaffin cells in the adrenal medulla is induced solely by hypercalcemia is not available. In this study, calcium gluconate was intravenously infused for 7 days to rat chromaffin cells by a tail cuff method, and cumulative labeling with bromodeoxyuridine (BrdU) was carried out to evaluate the proliferative activity. The serum calcium concentration was dose-dependently increased, and a high calcium concentration was stably sustained from day 2 to 7. In the adrenal medulla, BrdU-positive chromaffin cells increased in the calcium gluconate-treated animals, and the BrdU-labeling index increased in a dose-dependent manner. In addition, an increased BrdU-labeling index of chromaffin cells was shown to correlate with the serum calcium concentration. Our results demonstrate that hypercalcemia directly enhances the proliferative activity of chromaffin cells and that the proliferative activity is correlated with the serum calcium concentration.     

Removing aboveground vegetation facilitates survival but slows height growth of spruce saplings in a fenced, degraded sub-alpine forest in central Japan

The effects of removing aboveground vegetation on survival and growth of Hondo spruce (Picea jezoensis var. hondoensis) saplings were examined in a dense dwarf bamboo (Sasa nipponica) field inside a deer-proof fence built in a degraded sub-alpine forest on Mt Ohdaigahara, central Japan. All bamboo culms were removed within a radius of 1 m from each sapling in a plot of 0.6 ha (removal plot), whereas no culms were removed in two control plots of 0.1 ha. We measured the height, crown depth, and main shoot elongation over 1 year for all spruce saplings, culm height and cover ratios of dwarf bamboo growing around each spruce sapling, and the light levels above each sapling. Removal of dwarf bamboo regulated the culm height and bamboo coverage until the following summer such that light conditions improved. The mortality of saplings smaller than the average culm height was lower in the removal plot (0.89%) than in a control plot (5.9%). After bamboo removal, sapling height growth was reduced with increasing bamboo cover in the previous year. Complete removal of the aboveground portions of covering bamboo improved sapling survival while regulating elongation growth, possibly because of the sudden increase in light intensity. Thus, controlling the extent of dwarf bamboo removal might be necessary to facilitate the growth of spruce saplings to restore the forest.     

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.     

Effect of Intramammary Injection of RbIL‐8 on Milk Levels of Somatic Cell Count,Chemiluminescence Activity and Shedding Patterns of Total Bacteria and S. aureus in Holstein Cows with Naturally Infected‐subclinical Mastitis

The effect of intramammary injection of recombinant bovine interleukin‐8 (rbIL‐8, 1 mg/10 ml of saline) on quarter milk levels of somatic cell count (SCC), chemiluminescence (CL) activity and counts of total bacteria and Staphylococcus aureus (S. aureus) was investigated, using 10 Holstein cows with an early stage or a late stage of subclinical mastitis naturally infected with S. aureus. In the late‐stage group, milk SCC and CL activity had significant rises with maximum levels at 6 h, following maintained high levels thereafter post‐cytokine injection. The counts in milk total bacteria and S. aureus were insignificantly decreased, being increased back on day 7 post‐cytokine injection. Thus, the cytokine was inefficient for the late‐stage subclinical mastitis. However, in the early‐stage group milk SCC and CL activity declined to under pre‐injection levels on day 7 after marked and significant rises at 6 h and day 1 post‐cytokine injection. The milk total bacterial count decreased significantly on days 0.25 and 2. Furthermore, the milk S. aureus count was decreased significantly on days 1, 2, 3 and 7 by the cytokine injection. These results suggest that the rbIL‐8 has a potential as a therapeutic agent of the subclinical mastitis of dairy cows, if the cytokine is applied at an initial stage of infection.     

GH secretory responses to ghrelin and GHRH in growing and lactating dairy cattle

Release of growth hormone (GH) is known to be regulated mainly by GH-releasing hormone (GHRH) and somatostatin (SRIF) secreted from the hypothalamus. A novel peripheral release-regulating hormone, ghrelin, was recently identified. In this study, differences of the GH secretory response to ghrelin and GHRH in growing and lactating dairy cattle were investigated and an alteration of plasma ghrelin levels was observed. The same amounts of ghrelin and GHRH (0.3 nmol/kg) were intravenously injected to suckling and weanling calves, early and mid-lactating cows and non-lactating cows. Plasma ghrelin levels were also determined in dairy cattle in various physiological conditions. The peak values of ghrelin-induced GH secretion were increased in early lactating cows compared to those in non-lactating cows. The relative responsiveness of GH secretion to ghrelin was also increased compared with that to GHRH in early lactating cows. GH secretory responses to GHRH were blunted in mature cows with and without lactation. Conversely, GHRH-induced GH secretory response was greater than that to ghrelin in calves, and also greater in calves than in mature cows. Plasma ghrelin concentrations were elevated in early lactating cows compared to those in non-lactating cows. Plasma GH concentrations were higher in suckling calves and early lactating cows compared with those in non-lactating cows. These results suggest that GHRH is an effective inducer of GH release in growing calves, and that the relative importance of ghrelin in contributing to the rise in plasma GH increases in early lactating cows.     

A case study of infection of rice roots by deleterious fungi and minor pathogenic<Emphasis Type="Italic"> Pythium</Emphasis> species in a paddy field

Roots of rice plants grown in paddy fields in a transplant culture system were collected seven times between 8 and 22 weeks after transplanting, for two crop seasons. Rice seedlings grown in a potting medium amended with the collected roots were significantly shorter than those grown in the same medium either without the addition of the roots or amended with pasteurized, collected roots indicating that seedlings were inhibited by heat-labile microorganisms on the collected rice roots. Ninety-five and 172 pure cultures of Pythium spp. and fungi, respectively, were isolated from the rice roots collected 5 or 7.5 weeks after transplanting in the fields. Among these microorganisms, Pythium aristosporum inhibited seedling growth in greenhouse experiments, and Acremonium sp., Alternaria sp., Epicoccum nigrum, Fusarium sp., Massarina sp., Penicillium spp., Rhinocladiella sp., Stemphylium sp., Trichocladium sp., and several unidentified fungi inhibited seminal root growth in in vitro experiments. These microorganisms might be involved in the inhibition of seedling growth in soils amended with the rice roots collected from the paddy field. Thus, roots of rice plants at the middle stage of growth transplanted into paddy fields can harbor pathogenic or deleterious fungi or Pythium sp(p). The effects of these microorganisms on rice growth in paddy fields are discussed.     

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.