Bovine pituitary intraglandular colloid fraction F5 localized in the rat endocrine pancreas

Bovine pituitary intraglandular colloid thought to be a waste product, is the holocrine secretion of intermediate lobe cells. It is housed in the intraglandular lumen (residual lumen) and is extruded into the venous circulation of the cavernous sinuses via clefts in the capsule of the gland aligned with the intraglandular lumen. Intraglandular colloid, fraction F5 (mol.wt 34,000), radiolabeled with (125I)Na and injected (0.15 ml) into the right internal jugular vein of male Wistar rats, accumulated in the endocrine pancreas. Autoradiographs showed that the material had specifically localized in the capillary network of the endocrine pancreas. Since the intermediate lobe is poorly vascularized, intraglandular colloid is considered to be the transport medium for intermediate lobe materials.     

The relationship of intraglandular colloid production to hormone synthesis

Summary The production of intraglandular colloid, brought about by the cyclic breakdown of intermediate lobe cells, is related to the synthesis of hormones in the hypophysis. By analyzing the shift of the amino acid, cystine, during various phases of the gland's cycle it is apparent that hormones, as well as other protein determinants of immunological importance, are transported by way of the intraglandular cleft to the venous circulation and to the cerebrospinal fluid.This study was supported by a grant from the National Research Council of Canada.     

Evolutionary implications of ascorbic acid production in the Australian lungfish

Summary It is shown that the Australian lungfish (Neoceratodus forsteri) synthesizes ascorbic acid in its kidney, suggesting that ascorbic acid synthesis started before the origin of the tetrapods.Acknowledgments. We would like to thank Dr G.C. Grigg, University of Sydney, Mr R. B. Humphries, Dr P.A. Janssens and Dr C.H. Tyndale-Biscoe, Australian National University, and Dr. M. Griffiths and J.C. MacIlroy C.S.I.R.O., Division of Wildlife Research for supplying the tissue.     

Purification and properties of glutamine synthetase I fromRhizobium sp. UMKL 20

Summary Glutamine synthetase I was purified fromRhizobium sp. UMKL 20 following polyethylene glycol precipitation. The enzyme had a subunit molecular weight of 58 kd. Apparent K_m values for ammonia and glutamate were 5.6 and 15.2 mM, respectively. Glutamine synthetase I activity was inhibited by several end products of glutamine metabolism. The purified enzyme was highly adenylylated (E _n ^– =8.5).Acknowledgment. I would like to thank Mr J. C. Lai for technical assistance. This work was carried out with the support of Vote F 153/79 from the University of Malaya.     

A novel biochemical systematic technique for herpetology based on epidermal keratin

Summary Using green geckos (Phelsuma) the molecular weights and isoelectric points of S-carboxymethylated keratin monomers from fresh and preserved reptile epidermis were investigated. Isoelectric focussing reveals that several of the circa 35 components differ between genera, species and races and that the relative similarity of the SCMK pattern is directly related to evolutionary similarity and is of considerable taxonomic value.We would like to thank the SRC (grant A/8799.9 to R.S. Th.) and the Department of Zoology, Aberdeen for funding this research and Dr Alan Knox for his advice and assistance at the inception of this project. R.S. Th. would like to thank the Bonhote fund, Carnegie Trust and the Joint Research Committee of Aberdeen University for travel expenses related to this research and the Reptile and Amphibian section of the BMNH for the loan of specimens. M. G. would like to thank J.M. Gillespie for communications on keratin biochemistry and Dr Charteris (BDH) for a sample of their molecular weight markers prior to it being marketed.     

Bombesin,calcitonin and leu-enkephalin immunoreactivity in endocrine cells of human lung

Summary By immunohistochemistry, bombesin, calcitonin and leu-enkephalin was localized in endocrine cells of human lungs from various age groups. It is suggested that at least 3 different peptide containing endocrine cells may be present in human lung.Acknowledgments. The authors thank Dr Camille Vaillant, University of Liverpool, for advice with immunohistochemical methods and Dr G. Dockray for his generous gift of bombesin antiserum. This work has been supported by Medical Research Council of Canada (MA-7054) and Ontario Thoracic Society.     

Endocrine cells producing regulatory peptides

Recent data on the immunolocalization of regulatory peptides and related propeptide sequences in endocrine cells and tumors 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 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 peptides are 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, alpha-MSH and CLIP (corticotropin-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 adrenaline-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.     

Primary neural induction as studied by scanning electron microscopy

Summary Normal primary neural induction has been studied by scanning electron microscopy and the results compared with those obtained by TEM. Mesoderm cells are usually in contact with several other cells, both mesodermal and endodermal in origin. By SEM the ectoderm layer has been shown to be in contact with the underlying mesoderm cells. Tufts of fibrous basement membrane are also present between the two cell types. TEM specimens also show an intermediate basement membrane.Acknowledgments. M. A. E. would like to thank ProfessorF. Beck in whose department this work was conducted. An especial acknowledgment to Mrs.Wendy Nugent for her skilled technical assistance in the preparation of the SEM and TEM specimens. Mr.Duncan Boreham, Electron Microscope Unit, University of Leicester kindly offered assistance and advice.S. V. C. would like to thank ProfessorR. P. Dale in whose department the SEM photographs were prepared.     

Occurence of diploid drones in a neotropical bumblebee

Zusammenfassung Mutter-Sohn-Kreuzung bei der südamerikanischen HummelBombus atratus Franklin ergab diploide Männchen mit normalen Arbeiterinnen im Verhältnis von 3 zu 1. Tur Interpretation des genetischen Mechanismus wurden 2 geschlechtsgebundene Loci angenommen, als bisher angenommen wurde, was für einen älteren Mechanismus bei Apiden spricht.

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This study was made possible by a grant of the State of São Paulo Research Foundation (FAPESP).

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Acknowledgment. I would like to thank Dr.W. E. Kerr, Dr.R. Zucchi and Dr.S. F. Sakagami for their excellent assistance during the course of this investigation as well during the translation. I also would like to thank Dr.R. H. Crozier for his suggestions and comments and I extend my thankfulness to professorsJ. Chaud Netto andZ. Silveira.     

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.     

The composition of Taft E s o constants: An application of biased alternatives to least squares

Summary A systematic analysis of the composition of E _s ^o like rate constants clearly revealed that Taft E _s ^o -values depend upon the size of the substituents. Further evidence in favor of this view is adduced even in a case where OLS led to the conclusion that E _s ^o should be completely independent of the size of the substituents, since biased estimators (PCRA, LRRA) showed that this statement is not correct. Furthermore, it seems that the magnitude of the steric effect represented by E _s ^o is a function of the thickness of the substituent along 2 directions perpendicular on its main axis and is not influenced by its length.Acknowledgment. We would like to thank Prof. J.T. Webster, Department of Statistics, Southern Methodist University, Dallas, for sending us s computer program of latent root regression analysis. We also thank the referees whose insightful comments were most helpful in improving the presentation.     

Photoreceptor properties of an ectopic eye in the fleshfly,Sarcophaga bullata

Summary Ectopic eyes were produced on the fleshfly,Sarcophaga bullata by transplantation of imaginal eye discs. Electrophysiological and histological observations of these supernumerary eyes indicate the absence of synaptic connections between retinular cells and higher order neurons.Supported by an University of New Brunswick research grant to P.S. and NSF grant BNS-76-11921 and NIH grant 1-R01-EY-02487-01A1 to W.S.S.We would like to thank Dr I.A. Meinertzhagen for suggestions and Mary Johnson for technical assistance.     

Commercially available equipment suitable for post-implantation embryo culture

Summary There is a need for commercially manufactured equipment for use in post-implantation embryo culture techniques. A simple, inexpensive modification to an existing device is described that enables such an apparatus to be used for the roller-tube technique.Acknowledgments. I would like to thank Drs R.D. Barnes and F.E. Hytten for much encouragement and provision of facilities. Also, the Obstetric Research Fund, University College Hospital Medical School for financial support.     

Identification of teleost gonadotrope cells using methallibure (I.C.I. 33, 828) and thiourea

Zusammenfassung Die versuchsweise Identifizierung gonadotroper Zellen der Teleostier-Hypophyse (Plectoplites ambiguus) gelang nach Behandlung mit Methallibure (I.C.I. 33, 828) und Thiourea.

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The work was supported by a University of Sydney Research Grant. I thank Mr.J. Collard, of the Veterinary Division of I.C.I.A.N.Z. Ltd., for supplies of Methallibure and Mrs.M. Weinstock for her technical assistance.     

Effect of exercise on ribonuclease activity in rat skeletal muscle

Summary Distribution of ribonuclease activity (measured at pH 7.6) in subcellular fractions of homogenates of rat skeletal muscle was investigated in sedentary animals and after 8 weeks running program. Training increased ribonuclease activity (expressed as units of enzyme per g of muscle protein). There was no increase in nuclear fraction, but in both cytoplasmic and mitochondrial fractions the RNA-ase activity increased 42% and 45% respectively.Acknowledgments. I would like to thank Prof. L. elewski and Dr J. Popinigis for helpful suggestions.     

On induced fragmentation of ovarian oocytes

Summary Fragmentation of oocytes was induced in the ovary, via ovulation suppression, by administration of dehydro-epiandrosterone acetate (DHA-Ac) to mature cycling rats. The maximal fragmentation ratio, 15.0±3.2%, was obtained by 10 mg/100 g b.wt/day for 7-day administration of DHA-Ac. The relationship of fragmentation to the first stage of meiosis is also discussed.Acknowledgments. The author would like to thank Professor T. Matsuda in the Department of Anatomy I for his valuable advices and Proff. E. Nishida and K. Akasofu in the Department of Obstetrics and Gynecology, Kanazawa University, for instructive suggestions and for kindly supplying DHA-Ac.     

Reading Gauss in the Computer Age: On the U.S. Reception of Gauss’s Number Theoretical Work (1938–1989)

C.F Gauss’s computational work in number theory attracted renewed interest in the twentieth century due to, on the one hand, the edition of Gauss’s Werke, and, on the other hand, the birth of the digital electronic computer. The involvement of the U.S. American mathematicians Derrick Henry Lehmer and Daniel Shanks with Gauss’s work is analysed, especially their continuation of work on topics as arccotangents, factors of n ² + a ², composition of binary quadratic forms. In general, this strand in Gauss’s reception is part of a more general phenomenon, i.e. the influence of the computer on mathematics and one of its effects, the reappraisal of mathematical exploration. I would like to thank the Alexander-von-Humboldt-Stiftung for funding this research. For their comments I would like to thank Catherine Goldstein, Norbert Schappacher and especially John Brillhart.     

Effect of cholesterol oxidation on (Na+, K+) ATPase activity of erythrocyte membranes

Summary By incubation of human erythrocyte ghosts with cholesterol oxidase (EC 1.1.3.6) part of the cholesterol of the membrane is replaced by 4-cholesten-3-one. This alteration in the sterol composition is accompanied by an inhibition of the (Na⁺, K⁺) ATPase of the erythrocyte membrane.Acknowledgments. This study was supported by the Deutsche Forschungsgemeinschaft Bonn-Bad Godesberg and the Sonderforschungsbereich 90 of the University of Heidelberg. We thank Mr.J. Schmidt and MissI. Geldmacher for skilful technical assistance.     

Spruce budworm: Effects of different blends of sex pheromone components on disruption of male attraction

Summary Disruption of attraction of maleChoristoneura fumiferana to the natural sex pheromone in an atmosphere permeated by blends of the 2 pheromone components is greatest with ratios of the 2 components close to the natural blend.The (E)- and (Z)-TDALs were obtained from ChemSampCo, Columbus, Ohio, and were further purified by argentation column chromatography on Hi-Flosil-Ag (20% AgNo₃), 60/200 mesh, eluting with 91 pentane: ether. Following formulation, (E)(Z) ratios in the PVC were determined by extracting PVC pellets for 6 h in hexane and analyzing the solvent by GLC. The chemical analyses and purifications were carried out by Ms Linda MacDonald of the Forest Pest Management Institute, Sault Ste. Marie, Ont., to whom I would like to express my thanks.Analyses of the data were done with the help of Dr J. Régnière of the Great Lakes Forest Research Centre, Sault Ste. Marie, Ont. whom I would also like to thank.     

Bacteria as cell surface markers on normal and malignant mammalian cells

Zusammenfassung Bakterien haften an der Oberfläche kultivierter Säugetierzellen in charakteristischer Weise. An Krebszellen haften sie nicht nur am Vorderteil, sondern auch an der Zelloberfläche und in Kernnähe.

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I thank the Royal Society for some of the equipment used in this research, the Nuffield Foundation for the award of a fellowship, and Prof.I. M. Goodbody for facilities in the Department of Zoology, University of the West Indies, Jamaica, while on sabbatical leave of absence from the University of Glasgow. I am also indebted toJ. B. Cowey, A. S. G. Curtis andD. R. Newth, of Glasgow University for their criticisms and advice, and to Miss E. Cray for assistance in the experiments.