High and low affinity opioid binding sites: relationship to mu and delta sites

Binding and pharmacological studies suggest a common opiate and enkephalin binding site in addition to their previously reported selective sites. This common high affinity site has tentatively been named mu1, distinguishing it from the morphine-selective site (mu2) and enkephalin-selective site (delta). The existence of this additional common high affinity site and its association with opiate and opioid peptide analgesia may help explain some pharmacological observations, such as the cross tolerance between morphine and enkephalin analgesia and the lack of cross tolerance between them in the guinea pig ileum and mouse vas deferens bioassays.     

Effect of salinity on quality of various agricultural crops

Summary The effect of salinity on the quality of various agricultural crops has not yet been explored much. This information is very important to Israel due to the increasing use of saline water for irrigation. This paper reports the effect of saline irrigation water on the quality, especially the taste, of several crops. Fruits from a processing tomato cultivar exposed to various degrees of salinity had higher values for total soluble solids (TSS) and acidity than their controls. The yield of fruit after saline water irrigation is lower, but this is offset by the nigher fruit quality and its consequent higher value. Melon fruits from plants subjected to saline water scored higher in taste than their controls when the fruits were analyzed fresh. After 3–4 weeks of storage at room temperature, there was no longer any difference in taste. Even though salinity slightly increased the TSS content, this did not correlate with the taste scores. Iceberg lettuce grown with saline water did not significantly differ in taste from its control, even when the sensitive triangle taste test was used. The same was true for peanuts. Thus, for these two crops no advantage of better quality would compensate for possible lower yields. Salinity had little effect on the yield of two varieties of Chinese cabbage, but increased the frequency of tipburn.     

Eimeria spp. of the domestic fowl: resolution of chromosomes by field inversion gel electrophoresis

The molecular karyotypes of five species of chicken coccidia, viz., Eimeria acervulina, E. brunetti, E. maxima, E. necatrix, and E. tenella, were determined using field inversion gel electrophoresis (FIGE). Each species has a distinctive set of resolvable chromosomes which range from about 1 to greater than 5.7 megabases. We were able to resolve at least 8 chromosomes for E. acervulina, 5 for E. brunetti, 10 for E. maxima, 6 for E. necatrix, and 9 for E. tenella. If the value of 67 megabases for the genomic DNA of E. tenella is accurate, then under the conditions used here only about 60% of its chromosomal complement has been resolved.     

Resting stages in the life cycle of Eudiaptomus graciloides (Lill.) (Copepoda: Calanoida) in Lake Glubokoe

Seasonal changes in the abundance, age composition, vertical distribution, lipid and protein body content, development rates in the older copepodids (CIV and CV) and reproduction characteristics were studied in Eudiaptomus graciloides in the mesotrophic Lake Glubokoe (Moscow) region). Two periods of reproduction were observed: spring and late summer/autumn. The older copepodids, having accumulated lipid reserves during phytoplankton bloom, descended into the meta- and hypolimnion at the beginning of the summer. These copepods did not feed, but instead consumed their lipid reserves. A considerable delay in development (up to 40-60 days) of CIVs and CVs was found. The descended CIVs and CVs incubated under ambient temperature developed 4-5 times slower than their surface counterparts, while temperature dependence could only account for a 2-fold slow down. The descended copepods are believed to form a summer resting stock. In October, females began to produce resting eggs. The period of switching from subitaneous to resting egg production was very brief, not longer than 2-3 weeks. The percentage of subitaneous eggs produced in mid-October tended to increase when females were exposed to an increased photoperiod. At the beginning of February, latent eggs kept in a cooling container in the darkness started hatching. This process could be speeded up under natural photoperiod and increased temperature. The over-wintering population consisted largely of adults. Thus, E.graciloides includes three types of diapause in the life cycle: resting eggs, summer resting stage at CIV-CV, and overwintering adults.      

Phospholipid synthesis and degradation during the life-cycle of P815Y mast cells synchronized with excess of thymidine

1. P815Y cells synchronized with excess of thymidine incorporate choline, proline and uridine throughout the cell cycle; the rate increases two- to four-fold during the S phase, when thymidine incorporation increases more than 15-fold. 2. Choline incorporated at any stage of the cell cycle turns over in a biphasic manner; stable and unstable components are each labelled maximally during the S phase. Total phospholipid also doubles predominantly during the S phase. 3. It is concluded that, despite turnover, choline incorporation is a useful measure of net phospholipid formation during the cell cycle.