Association between changes in plasma calcium concentration and plasma tartrate-resistant acid phosphatase activity in periparturient cows

Eight periparturient Holstein Friesian cows were examined for plasma tartrate-resistant acid phosphatase (TRAP) activity to assess the degree of bone metabolic activity and to evaluate the association between the change in calcium (Ca) concentration and bone metabolism during the periparturient period. Milk fever occurred in 1 of 8 cows just after parturition. Plasma TRAP activities did not markedly change in 5 of 8 cows during the experimental period. The changing rate of Ca between preparturition and just after parturition was under -20% in 3 of 8 cows, and low TRAP activities were observed in 2 of these 3 cows. This study suggests that cows with a low TRAP activity are at risk of developing milk fever in comparison to cows with high TRAP activity. Temporary increases of parathyroid hormone were observed in 7 cows, but not in the cow with milk fever.     

Effects of supplement feeding order on lactation, diurnal variation of ruminal ammonia and urea in the blood and milk of dairy cows

The present study examined the effects of feeding order of grain and protein supplements on ruminal nitrogen (N) loss through the diurnal variation of ruminal ammonia N and urea N in the blood and milk of dairy cows. Three ruminally fistulated cows were used in a 3 × 3 Latin square arrangement of treatments; that is, grain supplement fed at the first feed and then the protein supplement at the second (GS‐1st), protein supplement fed first and then the grain supplement (PS‐1st), and the grain and protein supplements mixed and divided into equal portions fed at each supplement feeding time (GP‐mix). No differences in the lactation parameters were observed among the treatments. In GS‐1st treatment, the increase in the concentration of ruminal ammonia N was inhibited after feeding, and the concentration was lower (P < 0.05) than with the other treatments 1–2 h after basal feeding. The concentrations of urea N in the blood and milk with the GS‐1st treatment were the lowest of all treatments throughout the sampling times, and were lower (P < 0.05) than with the GP‐mix treatment except for blood levels 1 h after basal feeding. The results suggest that grain feeding before protein feeding can reduce ruminal N loss.     

Molluscicidal and anti-feedant activities of diterpenes from Euphorbia paralias L

Nine known diterpene polyesters of segetanes, jatrophenes and paralianes have been isolated from the aerial parts of Euphorbia paralias L. The molluscicidal activity of isolated compounds was evaluated on Biomphalaria alexandrina (Ehrenberg). Paraliane diterpene, (2S,3S,4R,5R,6R,8R,12S,13S,14R,15R)-5,8,14-triacetoxy-3-benzoyloxy-15- hydroxy-9-oxo-paraliane, was the most potent compound against the snail. Anti-feedant activity was tested by a conventional leaf disc method against third-instar larvae of Spodoptera littoralis (Boisd). Jatrophene diterpene, (2R,3R,4S,5R,7S,8R,13R,15R)-2,3,5,7,15-pentaacetoxy-8-angeloyloxy-14,15- dioxojatropha-6(17)-11E-diene, had the highest anti-feedant activity among the compounds tested.     

Metabolism of lindane in house flies: Metabolic desaturation,dehydrogenation and dehydrochlorination,and conjugation with glutathione

In lindane-treated house flies, a cis-dehydrogenated metabolite, $\text{(}\text{36}\text{45}\text{)-}\text{hexachlorocyclohexene}$, was identified by gas-liquid chromatography and mass spectrometry. The in vitro metabolism study showed that in the presence of NADPH the microsomal fraction of house flies converted lindane to three hexane-soluble metabolites. This conversion was inhibited by piperonyl butoxide, SKF-525A, and carbon monoxide. These metabolites were identified as $\text{(}\text{36}\text{45}\text{)-}\text{hexachlorocyclohexene}$, $\text{(}\text{36}\text{45}\text{)- and (}\text{346}\text{5}\text{)-pentachlorocyclohexene}$ (PCCHE) by gas-liquid chromatography. They, as well as lindane, were excellent substrates for the reaction with the postmicrosomal fraction in the presence of glutathione. While the reaction with lindane-d₆ showed a significant deuterium isotope effect (6.82), that of $\text{(}\text{36}\text{45}\text{)-}\text{PCCHE-d}{}_5$ did not (1.18). Enzymatic conjugation with glutathione probably occurs at the stage of PCCHE.     

Total glutathione and glutathione reductase in bovine erythrocytes and liver biopsy

The goal of the present study was to measure the total glutathione level and glutathione reductase activity in bovine erythrocytes and liver biopsy. Five cows were injected intraperitoneally with DL-ethionine (12.5 mg/kg B.W.), and two control cows were injected with normal saline (0.9% NaCl). Ultrasonography guided liver biopsy, and blood samples were collected at 0, 4, 7 and 10 days after injection. The hepatic total glutathione level was significantly increased on Days 7 (p<0.05) and 10 (p<0.01), and hepatic glutathione reductase activity was significantly increased on Days 4 (p<0.05), 7 (p<0.01) and 10 (p<0.01). There were insignificant changes in the erythrocytic total glutathione level. The present study demonstrated that liver biopsy is a valuable tool for detecting oxidative stress and for diagnosing hepatic dysfunction in cattle from the viewpoint of the status of glutathione and glutathione reductase.     

Milk Progesterone Profile at and after Artificial Insemination in Repeat-Breeding Cows: Effects on Conception Rate and Embryonic Death

The aim of this study was to investigate whether the skim milk progesterone concentrations at artificial insemination (AI) and day of rise of post-ovulatory progesterone concentration thereafter affect the conception and embryonic death rates in repeat-breeding cows. Milk samples were obtained from 96 repeat-breeding cows that failed to conceive to three or more AIs. The samples were taken from the cows at the day of AI and three times/week until day 45 post-AI. Skim milk was obtained after centrifugation and used for progesterone assay. The cows with a progesterone concentration more than 0.5 ng/ml at AI showed a significantly higher incidence of late embryonic death than those having a progesterone concentration<0.5 ng/ml at AI (p<0.01). As the progesterone level at insemination rose, conception rate declined. A negative correlation was shown between conception rate and skim milk progesterone level at AI. Of 56 cows showing a rise of progesterone to 1 ng/ml or more within 6 days after AI, 28 cows (50%) conceived. On the contrary, only eight of 39 cows (20.5%) conceived when the progesterone rose up to 1 ng/ml after day 6 post-AI. We concluded that increased progesterone concentration at the time of AI and delayed rise of progesterone post-AI might lead to decrease in fertility in repeat-breeding cows.     

Antifungal activity of limonoids from Khaya ivorensis

Chemical investigation of the diethyl ether extract of the stem bark of Khaya ivorensis A Chev (Meliaceae) afforded ten limonoids of angolensates, ring D-opened limonoids and mexicanolides. The structures of the limonoids isolated were determined by comparison of their (1)H and (13)C NMR data with those reported in the literature. These compounds were evaluated for their antifungal activity against the plant pathogenic fungus Botrytis cinerea Pers. Methyl 6-hydroxyangolensate and 3,7-dideacetylkhivorin were also tested for their antifungal and antibacterial activities on several fungal and bacterial species. Methyl angolensate and 1,3,7-trideacetylkhivorin displayed the highest antifungal activity against B. cinerea, with respectively 62.8 and 64.0% mycelial growth inhibition at 1000 mg litre(-1), and 73.3 and 68.6% mycelial growth inhibition at 1500 mg litre(-1). 3,7-Dideacetylkhivorin showed stronger antifungal and antibacterial activities than methyl 6-hydroxyangolensate against all of the test fungi and bacteria except Penicillium expansum Link. This is the first report on the antifungal and antibacterial effects of these limonoids. Structure-antifungal activity relationships of the limonoids isolated are discussed.     

Negative feedback regulation ensures the one receptor-one olfactory neuron rule in mouse

In the mouse olfactory system, each olfactory sensory neuron (OSN) expresses only one odorant receptor (OR) gene in a monoallelic and mutually exclusive manner. Such expression forms the genetic basis for OR-instructed axonal projection of OSNs to the olfactory bulb of the brain during development. Here, we identify an upstream cis-acting DNA region that activates the OR gene cluster in mouse and allows the expression of only one OR gene within the cluster. Deletion of the coding region of the expressed OR gene or a naturally occurring frame-shift mutation allows a second OR gene to be expressed. We propose that stochastic activation of only one OR gene within the cluster and negative feedback regulation by that OR gene product are necessary to ensure the one receptor-one neuron rule.     

The neural basis of intuitive best next-move generation in board game experts

The superior capability of cognitive experts largely depends on quick automatic processes. To reveal their neural bases, we used functional magnetic resonance imaging to study brain activity of professional and amateur players in a board game named shogi. We found two activations specific to professionals: one in the precuneus of the parietal lobe during perception of board patterns, and the other in the caudate nucleus of the basal ganglia during quick generation of the best next move. Activities at these two sites covaried in relevant tasks. These results suggest that the precuneus-caudate circuit implements the automatic, yet complicated, processes of board-pattern perception and next-move generation in board game experts.