Cluster analysis to evaluate disease risk in periparturient dairy cattle

Predicting periparturient disease risk is of immense value to the dairy industry. Periparturient diseases are interrelated with each other; however, predicting the onset risk of these diseases has predominantly been based on a single blood parameter for a single disease. This study examined a new diagnostic method to predict the risk of periparturient diseases. We conducted cluster analysis of multiple blood constituents from 20 Holstein cattle at 1 week post‐partum, and the cattle were divided into two groups, A or B. We then compared the periparturient and early‐lactation blood constituents of these groups. Group B had significantly higher 3‐hydroxybutyric acid concentrations and were suspected to have subclinical ketosis. Group B also had significantly lower calcium concentrations, with a tendency for subclinical hypocalcemia. We also performed discriminant analysis using blood parameters at 1 week post‐partum, which grouped the population into the same two groups as the cluster analysis based on three variables: inorganic phosphorus, calcium, and either phospholipids or total cholesterol. We further showed that these discriminant functions could be used to predict the risk of periparturient disease even before parturition. Our results indicate that cluster analysis with multiple blood constituents is useful for predicting periparturient disease risks.     

Influence of uterine inflammation on the estrous cycle in rats

To investigate how uterine inflammation affects ovarian activity in rats, endometritis was induced and changes in the length of estrous cycle and serum concentrations of estradiol-17beta (E(2)) and progesterone (P(4)) were examined. A suspension of Staphylococcus aureus (bacterial solution) or iodine solution was infused into the uterine lumen at various estrous phases. When the bacterial solution was infused at estrus, metestrus, or the first day of diestrus, the following diestrus continued for 5 to 12 days. In the case of the iodine solution, regardless of the estrous phase of the infusion, the following diestrus continued for approximately 6 days. E(2) concentration after infusion of each solution did not fluctuate largely and remained at a low concentration (around 5 pg/ml). P(4) concentration was high (35-45 ng/ml) on the day following infusion, but decreased rapidly to base line values within a few days and remained thereafter at a low level (around 5 ng/ml). It is assumed that the endometritis caused by biological or chemical stimulation raises the concentration of P(4) to depress gonadotrophic hormone secretion, and hence this high P(4) concentration might inhibit the growth of ovarian follicles.     

Effects of oral exposure of bisphenol A on mRNA expression of nuclear receptors in murine placentae assessed by DNA microarray

Bisphenol A (BPA), a candidate endocrine disruptor (ED), is considered to bind to estrogen receptors and to regulate expressions of estrogen responsive genes. It has also shown evidence of affecting the reproductive, immunological and nervous systems of mammalian embryos. However, the effects of BPA on placentae, a central organ of feto-maternal interlocution, are still unclear. To reveal the mechanisms of BPA effects on placentae in mammals, we compared the mRNA expression of 20 nuclear receptors between placentae of vehicle controls and those of orally BPA exposed pregnant mice by a DNA microarray technique. In murine placentae, mRNAs of 11 nuclear receptors were not detected. However, greater than 1.5 fold changes in mRNA expression of nine nuclear receptors between vehicle control and BPA treated mice were noted. Moreover, remarkable changes in mRNA expression of six non-nuclear receptor proteins were induced by BPA exposure. There were various differences in the effects of BPA on the expression of these mRNAs between the placentae with male embryos and those with female embryos. Such embryo-sex dependent differences are interesting and important pointers to understanding of the endocrine disrupting effect of BPA. The present data indicate that BPA affects the expression of nuclear receptor mRNAs in placentae and may disrupt the physiological functions of placentae.     

Generation of viable calves derived from developmentally mature blastocysts produced by on-gel culture

Conventional culture systems for bovine embryos are unable to support sustained embryonic development until the developmentally mature blastocyst stage. Although we have previously developed an on-gel culture system that enables bovine blastocysts to complete cell segregation events at day (D) 10 following in vitro culture, the development of D10 blastocysts to term has yet to be achieved. In this study, we attained full-term development of D10 mature blastocysts produced using an on-gel culture system. Two calves derived from on-gel-cultured embryos were vaginally born, showing normal birth and placental weights and no obvious morphological abnormalities. Moreover, we detected no abnormalities in blood metabolic profile analyses. Our findings indicate that on-gel culturing can be used to facilitate the development of developmentally mature blastocysts to term, and produce healthy viable calves. This culture system could make a valuable contribution to cattle production and would enable a range of analyses for characterizing bovine-specific pre-implantation development.     

Adsorption of minerals on the isolated mantle of Patinopecten yessoensis

The isolated mantle of scallop ( Patinopecten yessoensis ) was shown to adsorb minerals (Zn, Ca, Mg, Fe, Cu, Ni and Co) to more than 1% upon treatment with mineral solution. The amounts of adsorbed Zn, Ca and Mg were 44.3, 47.4 and 15.5 mg/g dry weight, when the mantle was treated with 5% ZnSO₄, CaCl₂ and MgSO₄ solutions at room temperature, respectively. The amounts of adsorbed Zn, Ca and Mg were dependent on the concentration of mineral solution used. This is the first report showing that the isolated mantle adsorbs nutritionally important minerals such as Ca, Mg and Fe. This finding may lead to the development of new mineral-enriched food supplements.     

Thermal stress responses of a sterile mutant of Ulva pertusa (Chlorophyta)

SUMMARY: The thermal stress responses of a sterile mutant of the marine alga Ulva pertusa were investigated at 20°C and 30°C. The amounts of the photosynthetic pigments, β-carotene, chlorophylls a and b , lutein, neoxanthin, and violaxanthin, were 1.4–2.4 times higher in the 30°C-cultivated alga than in the 20°C-cultivated alga. The free amino acids, asparagine, aspartic acid, glutamine, glutamic acid, glycine, and serine, were abundant in the 20°C-cultivated alga, and increased 1.9–10.5-fold in response to thermal stress (30°C). Total carbon and nitrogen contents also increased in the 30°C-cultivated alga. Sodium dodecylsulfate-polyacrylamide gel electrophoretic patterns of total proteins extracted from both temperature-treated algae showed the increases of 20, 25, and 90 kDa proteins in the 30°C-cultivated alga. Isozyme assays for 20 enzymes showed a different banding pattern only in the case of glutamate dehydrogenase (GDH). Although it was observed that both temperature-treated algae possessed NAD⁺- and NADP⁺-specific GDH, the 30°C-cultivated alga had an additional NADP⁺-specific GDH (NADP-GDH). These results suggest that NADP-GDH compensates for the thermally induced decreases in nitrogen assimilation efficiency and thereby regulates nitrogen metabolism under conditions of temperature stress.