Adrenocortical metabolism and plasma corticosterone in soman intoxicated rabbits

Summary The organophosphate neurotoxin soman produced impairments in adrenocortical RNA and protein metabolism. Fasciculate and reticular cell RNA and protein contents were supporessed with sublethal to acutely lethal dosages (20, 30 and 40 g/kg, s.c.) during the acute excitatory phase of intoxication and at 6–8 h post injection. All three dosages produced ca 90% inactivation of plasma cholinesterase. A transient elevation of plasma corticosterone occurred with 20 g/kg soman whereas there was a protracted increase with 30 g/kg. Corticosterone was not significantly elevated with 40 g/kg, but death occurred at 13±4 min. Thus, the magnitude and/or nature of soman-induced metabolic impairments does not appear to prevent adrenal activation.Supported by US Army Medical Research and Development Command Contract DAMD 17-81-C-1202.     

Quantitative genetic models of sexual selection

Summary Quantitative genetic models of sexual selection have disporven some of the central tenets of both the handicap mechanism and the sexy son hypothesis. These results suggest that the good genes approach to sexual selection may generally lead to erroneous results.Runaway sexual selection seems possible under a wide variety of circumstances. Quantittive genetic models have revealed runaway processes for sexually selected attributes expressed in both sexes and for attributes of parental care. Furthermore, the runaway could occur simultaneously in a series of populations that straddle an environmental gradient. While the models support the feasibility of runaway processes, empirical studies are needed to evaluate whether runaways actually happen. Estimates of critical genetic parameters are particularly needed, as well as measures of natural and sexual selection acting on the same population.The models also show that sexual selection has tremendous potential to produce population differentiation, particularly in epigamic traits. Differentiation is promoted by indeterminancy of evolutionary outcome, transient differences among populations during the final slow approach to equilibrium, sampling drift among equilibrium populations, and the tendency of sexual selection to amplify geographic variation arising from spatial differences in natural selection. Recent work with two- and three-locus models of sexual selection has produced results that parallel the results of the polygenic models^36–38,58. Thus the feature of indeterminate equilibria (outcome dependent on initial conditions) is common to both types of model.     

Endorcine cells producing regulatory peptides

Summary Recent data on the immunologication of regulatory peptides and related propeptide sequences in endocrine cells and tumours of the gastrointestinal tract pancreas, lung, thyroid, pituitary (ACTH and opioids), adrenals and paraganglia have been revised and discussed. Gastrin, xenopsin, cholecystokinin (CCK), somatostatin, motilin, secretin, GIP (gastric inhibitory beenrevised and discussed. Gastrin, xenopsin, cholecystokinin (CCK), somatostatin, motilin, secretin, GIP (gastric inhibitory polypeptide), neurotensin, glicentin/glucagon-37 and PYY (peptide tyrosine tyrosine) are the main products of gastrointestinal endocrine cells; glucagon, CRF (corticotropin releasing factor), somatostatin, PP (pancreatic polypeptide) and GRF (growth hormone releasing factor), in addition to insulin, are produced in pancreatic islet cells; bombesin-related peptidesare the main markers of pulmonary endocrine cells; calcitonin and CGRP (calcitonin gene-related peptide) occur in thyroid and extrathyroid C cells; ACTH and endorphins in anterior and intermediate lobe pituitary cells, -MSH and CLIP (corticotropoin-like intermediate lobe peptide) in intermediate lobe cells; met- and leu-enkephalins and related peptides in adrenal medullary and paraganglionic cells as well as in some gut (enterochromaffin) cells; NPY (neuropeptide Y) in adrenalin-type adrenal medullary cells, etc.. Both tissue-appropriate and tissue-inappropriate regulatory peptides are produced by endocrine tumours, with inappropriate peptides mostly produced by malignant tumours.     

A new semisynthetic ergot peptide alkaloid: DCN 203-922

Summary We report the synthesis, stereochemistry and preliminary pharmacological evaluation of DCN 203-922, a novel ergot alkaloid of the cyclol type, which contains in its peptide moiety the uncommon amino acid L-allo-isoleucine.Part of this paper was reported by this author at the Herbstversammlung der Schweizerischen Chemischen Gesellschaft, Bern, in October 1986.     

Occurrence of thiaminase II inSaccharomyces cerevisiae

Summary It was found that cell-free extracts ofSaccharomyces cerevisiae contain thiaminase II which hydrolyzes thiamine and thiamine analogs. The possible involvement of this enzyme and thiamine-synthesizing enzymes in thiamine production from thiamine antagonists is discussed.30 September 1986Acknowledgments. We thank the late Dr S. Yurugi, Takeda Pharmaceutical Industries, Osaka, for his generous gifts of dimethialium, 2-northiamine, -hydroxyethylthiamine, hydroxymethylpyrimidine, 2-norhydroxymethylpyrimidine and hydroxyethylthiazole. We also thank Prof. H. Nakayama, Yamaguchi Women's College, for his kind supply ofEscherichia coli 70–17 and 26–43.     

Photoperiodic summation is temperature-dependent inPyrrhocoris apterus (L.) (Heteroptera)

Summary InPyrrhocoris apterus, a low temperature, 15°C, prevented the termination of diapause by long days and, unexpectedly, also the induction of diapause by short days. Both responses were enabled at a higher temperature, 26°C. In contrast to current concepts, it was proved that the summation of photoperiodic signals was temperature-dependent, since the morphogenetic development was prevented by starvation.     

The Young-Householder algorithm and the least squares multidimensional scaling of squared distances

It is shown that replacement of the zero diagonal elements of the symmetric data matrix of approximate squared distances by certain other quantities in the Young-Householder algorithm will yield a least squares fit to squared distances instead of to scalar products. Iterative algorithms for obtaining these replacement diagonal elements are described and relationships with the ELEGANT algorithm (de Leeuw 1975; Takane 1977) are discussed. In large residual situations a penalty function approach, motivated by the ELEGANT algorithm, is adopted. Empirical comparisons of the algorithms are given.An early version of this paper was presented at the Multidimensional Data Analysis Workshop, Pembroke College, Cambridge, July 1985. I want to thank Jan de Leeuw and Yoshio Takane for bringing the ELEGANT algorithm to my attention and for clarifying its rationale and notation. My thanks go also to Stephen du Toit for help with the ALSCAL computations reported in Section 7.     

稀土高碳当量灰口铸铁组织与性能的研究

本文研究了利用稀土合金改善高碳当量灰口铸铁质量的可能性,稀土合金对高碳当 量灰口铸铁组织和性能影响的规律,以及稀土夹杂物在铸铁各相中分布的规律．发现了 稀土合金加入量与铸铁的机械性能之间明显的对应关系——“双峰值效应”。对稀土高 碳当量灰口铸铁的某些高温机械、物理、化学性能进行了研究。结果表明稀土合金加入 到高碳当量灰口铸铁中以后能净化铁水,改善组织,并提高其性能．     

Differential effects of prostaglandins and isoproterenol on cAMP content and Na,K pump activity in rat submandibular acini

Summary The -adrenergic agonist isoproterenol and prostaglandins E₁ and E₂ (but not F₂) increased the cAMP content of rat submandibular acini in vitro, but only isoproterenol enhanced ouabain-sensitive⁸⁶Rb (K) uptake. These findings suggest that cAMP is not involved in the activation of the Na, K pump in salivary cells.     

An enzyme immunoassay for mouse epidermal growth factor utilizing a liquid phase double-antibody system

Summary An enzyme immunoassay for mouse epidermal growth factor (EGF) involving a liquid phase double-antibody system was developed. The EGF--galactosidase conjugate prepared was stable for at least 8 months. By this method, EGF was detectable at a concentration as low as 20 pg per tube. The concentrations of EGF in various tissues of mice are also presented.This work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan.