Spierule cells inDrosophila species

Summary Spherule cells are restricted to the larval stage and make up 5–16% of cells in the hemolymph. Their morphology varies between species, mainly due to the shape of their inclusions which may be oval (spheroidocytes), polyhedral (crystalloid cells), or clearly crystalline (crystal cells). These inclusions are very rich in tyrosine. They liquefy rapidly in vitro, whereby the cells become hyaline (coagulocytes).Acknowledgments. We thank Mr B. Barandun for excellent technical assistance. This investigation was supported by the Swiss National Science Foundation, grant No. 3.792.076.     

Novel synthesis of 2,4-diphenylpyrimido [4,5-b] quinoline

Summary Reaction of n-butyllithium in ether with 2-ethoxyquinoline and further reaction with benzonitrile gives 2,4-diphenylpyrimido [4,5-b] quinoline (I). With the use of lithium di-isopropylamide, compoundI is obtained in better yield without side products.We thank Prof. N. S. Narasimhan and Prof. V. K. Phansalkar for their interest in this work. We are also grateful to the Alexander von Humboldt Foundation, West Germany, and Walcot Gibbs Foundation, U.S.A.     

Birefringence signals and tension development in single frog muscle fibres at short stimulus intervals

Summary The early large birefringence signal and mechanical activity were studied together in isolated single fibres of frog skeletal muscle with double stimulation at short stimulus intervals (2–60 msec) at room temperature and at 4–6°C. In all fibres tested, extra tension and additional birefringence signal in response to the second stimulus appeared simultaneously and suddenly upon increasing the stimulus interval. The shape of the stimulus-interval versus tension-development curve makes it highly improbable that subthreshold calcium release occurs at shorter stimulus intervals; therefore, tension development reliably reflects Ca-release in these experiments. In contrast to the report by Suarez-Kurtz and Parker, birefringence signal and calcium release are shown not to be dissociated by double stimulation. This result supports the hypothesis that the early large birefringence signal is an intrinsic indicator of calcium release from the sr during EC-coupling in skeletal muscle.     

Social behaviour versus temperature in the ciliateColpidium campylum

Summary WhenColpidium campylum are put in an observation chamber, they form groups of hundreds or thousands of individuals. In a temperature gradient, these groups find their preferred temperature range within a few hours, whereas isolated individuals can achieve this in min. This difference is caused by the social tendency of these ciliates.To whom reprint requests should be addressed.     

Affinity chromatography of human serum proteins using matrix bound lectin fromViscum album L.

Summary The D-galactose specific lectin fromViscum album L. reacts with serum proteins that contain the corresponding D-galactopyranosyl residues. By affinity chromatography of human serum on lectin-sepharose IgM, ₂-macroglobulin, haptoglobin and -lipoprotein were quantitatively retained. Only parts of IgA, IgG and transferrin were retarded. The other serum proteins are unbounded as albumin, ₁A– and ₁C.     

Spatial distribution of the adaptation field of the surround response mechanism in type X cat retinal ganglion cells

Summary The surround response mechanism in on-center X-cells in cat retina was found to be bimodally distributed and weak or nonexistent in the receptive field middle. An on-inhibition measure was used to assess surround mechanism gain.Acknowledgments. This research is supported by Public Health Service grant No. EY 00701.     

Circadian change of sweating rate measured locally by the resistance hygrometry method in man

Summary There existed circadian change in the sweating rate locally measured from the anterior of the left thigh: the sweating rate showed a remarkable decline during the period 2.00–5.00 h, while at other times throughout the day it generally remained high. This reduction seemed to be independent of sleep or sleeplessness.Acknowledgment. The authors thank sincerely the late Prof. S. Mizunashi for her constant encouragement throughout the work. This research was aided by a grant from Japan Chemical Fiber Association.     

Accumulation of Phosvel in adipose tissue of hens

Summary Phosvel, an organophosphorus pesticide, was stored in the adipose tissue of hens after they were given daily a single oral dose. The concentration of Phosvel in fat was related to the size of the daily dose.Acknowledgment. The authors are grateful to Prof. Yoshito Tsuji for his valuable suggestions; to Mr Mitsuo Kaneda and Mr Kazuo Sasaki for their technical assistance.     

A simple one-step procedure for staining the nucleolus organizer regions

Summary A simple silver staining technique for routine use is described by which the nucleolus organizer regions of mammalian chromosomes, including those of mouse chromosomes, are stained selectively.Acknowledgment. We would like to thank Prof. Dr K. Sperling for critical and helpful discussion.