Pars intermedia: unitary electrical activity regulated by light

In the pars intermedia of frogs in the dark two types of spontaneously firing neuronal units have been found; one can be inhibited by and the other is indifferent to increases in illumination. The receptor for the light-inhibited units appears to be the pineal organ. Transection experiments indicate that the axons to the two kinds of units in the pars intermedia are separately grouped in the floor.     

Effects of Lepidium meyenii Walp and Jatropha macrantha on blood levels of estradiol-17 beta, progesterone, testosterone and the rate of embryo implantation in mice

The effects of two Peruvian folk medicines, Lepidium meyenii Walp and Jatropha macrantha, on mouse sex steroid hormones and embryo implantation were investigated. Progesterone levels increased significantly in mice that received L. meyenii Walp, while testosterone levels increased significantly in mice that received L. meyenii Walp as well as in those that received both L. meyenii Walp and J. macrantha. However, there were no marked changes in blood levels of estradiol-17beta or the rate of embryo implantation.     

Complete set of extrachromosomal DNAs from three pathogenic lines of onion yellows phytoplasma and use of PCR to differentiate each line

 Two lines of onion yellows phytoplasma with reduced pathogenicity have been isolated from the original wild-type line (OY-W). One is a line with mild symptoms (OY-M) and the other is a non-insect-transmissible line, also with mild symptoms (OY-NIM). We previously reported heterogeneity in extrachromosomal DNA (EC-DNA) species in these lines. In this report, another EC-DNA, EcOYNIM, from OY-NIM was cloned and sequenced, providing a complete set of EC-DNAs from the three OY lines. To monitor each phytoplasma in synergism or cross-protection experiments, a pair of polymerase chain reaction (PCR) primers that universally amplify a portion of the EC-DNAs that are characteristic of each line was designed. Using this primer set, a line-specific fragment was amplified from the total DNA of each plant inoculated with one or more phytoplasma lines. The PCR product sizes differ for each phytoplasma line, so the lines can be distinguished even in plants infected with multiple lines. Because EC-DNAs are more abundant than chromosomal genes in phytoplasma cells, this primer set will be valuable for detecting and discriminating these phytoplasma lines and for analyzing their interaction. Received: October 21, 2002 / Accepted: January 8, 2003 RID="*" ID="*" The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under the accession number AB097150 Acknowledgments This work was supported partly by Grants-in-Aid of Scientific Research from the Japan Society for the Promotion of Science (JSPS) (09460155 and 13306004), a Grant-in-Aid of Scientific Research on Priority Areas (C) “Genome Biology” from the Ministry of Education, Culture, Sports, Science, and Technology of Japan, and the Program for the Promotion of Basic Research Activities for Innovative Biosciences (PROBRAIN) of the Bio-oriented Technology Research Advancement Institution.     

The development of a sensitive enzyme immunoassay for the determination of estrone and estradiol-17beta in bovine blood plasma based on the same homologous combination with antiserum and steroid-enzyme conjugate

The development of a sensitive enzymeimmunoassay (EIA) for the determination of estrone (E1) and estradiol-17beta (E2 beta) in bovine plasma is described. The assay is a homologous double-antibody EIA with E2beta 17hemisuccinate (HS) as hapten for the immunoreactive reagent. The antiserum was raised against E2beta 17HS bovine serum albumin conjugate in the rabbit, and E2beta 17HS-horseradish peroxidase was used as steroid-enzyme conjugate. Each estrogen EIA was distinguished only by using the each working standard and sample for the EIA. Bovine plasma E1 and E2beta were extracted and purified before EIA. The antiserum was used at 1:1,750,000 dilutions for EIA. Estrone and E2beta showed high cross-reactivity with the antiserum (E1: 350.7%, E2beta:100%). The sensitivities were <0.03 pg/well for E1 and <0.12 pg/well for E2beta. Recovery rates of E1 and E2beta added to bovine blood plasma were 94.5% and 93.9%, respectively. The precision for EIA of estrogens was below 9.7%. The profiles of either estrogen as determined by EIA corresponded closely well with follicle dynamics in the cow during the estrous cycles and with placental function in pregnant animals. In conclusion, our new EIA can be applied with sufficient sensitivities, recovery and precision for the routine analysis of E1 and E2beta concentrations in bovine plasma.