Inactivation (Desensitization) of the acetylcholine receptor inElectrophorus electricus membrane vesicles by carbamylcholine: Comparison between ion flux and α-bungarotoxin binding

Summary The inactivation (desensitization) of the acetylcholine receptor by carbanylcholine, a stable analogue of acetylcholine, has been investigated in eel Ringer's solution, pH 7.0, 0°C, by measurements of (i) ion flux and (ii) the kinetics of the reaction of [¹²⁵I]--bungarotoxin with the receptor. The effect of preincubation with carbamylcholine is significantly different in the two types of measurement. In both the receptor-controlled flux of inorganic ions and the toxin-binding kinetics a biphasic process has been observed (Hess, G.P., Lipkowitz, S., Struve, G.E., 1978,Proc. Nat. Acad. Sci. USA 75:1703; Hess, G.P. et al., 1975,Biochem. Biophys. Res. Commun. 64: 1018; Bulger, J.E. et al., 1977,Biochemistry 16: 684), only the initial fast phase of which is inhibited and the subsequent slow phase persists. However, preincubation with carbamylcholineper se has no effect on the toxin reaction. The results obtained are consistent with the proposal of Katz and Thesleff (Katz, B., Thesleff, S., 1957,J. Physiol. (London) 138: 65) that the active form of the receptor is converted to an inactive form in the presence of acetylcholine receptor ligands, and with our previous experiments (Hess et al., 1978) which indicated that one receptor form is responsible for the initial fast phase of both the receptor-controlled ion flux and the toxin binding reaction, and that its conversion to the other form results in the slow phases in these two measurements.     

Besprechungen/Reviews

Book reviewed in this article: Zeitschriften/Periodicals: Rothstein, St. I (1978): Mechanisms of avian egg-recognition: additional evidence for learned components Zeitschriften/Periodicals: Nash, L. T. (1978): The development of the mother-infant relationship in wild baboons Zeitschriften/Periodicals: Preston, J. L. (1978): Communication systems and social interactions in a goby-shrimp symbiosis Zeitschriften/Periodicals: Wodinsky, J. (1978): Feeding Behaviour of broody female Octopus vulgaris Zeitschriften/Periodicals: Ridley, M. (1978): Paternal care Zeitschriften/Periodicals: Huber, F. (1978): The insect nervous system and insect behaviour Zeitschriften/Periodicals: Sandow, J. D. , und W. J. Bailey (1978): An experimental study of defensive stridulation in Mygalopsis ferruginea Redtenbacher Zeitschriften/Periodicals: Rohwer, S. , und F. C. Rohwer (1978): Status signalling in Harris Sparrows: Experimental deceptions achieved Zeitschriften/Periodicals: Perron, F. E. (1978): Locomotion and shell-righting behaviour in adult and juvenile Aporrhais occidentalis Zeitschriften/Periodicals: Platt, St. A. (1978): A re-examination of animal tropisms Zeitschriften/Periodicals: Wells, K. D. (1978): Territoriality in the green frog Zeitschriften/Periodicals: Stallcup, J. A. , und G. E. Woolfenden (1978): Family status and contributions to breeding by Florida scrub jays Zeitschriften/Periodicals: Wood-Gush, D. G. M. , und M. J. Gentle (1978): The hyperstriatum and nesting behaviour in the domestic hen Zeitschriften/Periodicals: Andersson, M. , und Ch. G. Wiklund (1978): Clumping versus spacing out: Experiments on nest predation in fieldfares Bücher/Books: Silver, R. , and H. H. Feder, eds. (1979): Hormones and reproductive behavior Bücher/Books: Lloyd, H. G. (1980): The red fox (Der Rotfuchs) Bücher/Books: Warner, L. J. (1979): Mammal Photography and Observation. A Practical Field Guide Bücher/Books: Miller, P. J., ed. (1979): Fish Phenology. Anabolic Adaptiveness in Teleosts Bücher/Books: Kraus, O., ed. (1978): 20. Phylogenetisches Symposion: Co-Evolution Bücher/Books: Frisch, K. v. (1980): Fünf Häuser am See—Der Brunnwinkl, Werden und Wesen eines Sommersitzes     

Selection intensity in the Pahiras

Quantitative Genetic Variation: Edited by James N. Thompson, Jr., and J. M. Thoday. Academic Press, New York, 1979. $19.50

Sociobiology examined: Edited by Ashley Montagu. Oxford University Press, New York and Oxford, 1980. $19.95, cloth; $5.45, paper.

The biology of aging: Edited by John A. Behnke, Caleb E. Finch, and Gairdner B. Moment. Plenum Press, New York, 1978. $18.95     

Comparison of time constants of single channel patches,quantum bumps,and noise analysis inLimulus ventral photoreceptors

Summary The characteristic time constants derived from three different experimental procedures for measuring light-evoked currents in photoreceptors are compared; these procedures include single-channel patch-clamp measurements, noise analysis, and current relaxation studies. Recent patch-clamp measurements of the mean open times of single light-activated channels in the ventral photoreceptor ofLimulus (Bacigalupo, J., Lisman, J.E. (1983),Nature (London) 304:268–270) yield a disagreement of the measured mean open time with the relaxation time of the falling phase of quantum bumps and with the inverse characteristic frequency of the noise power spectrum, measured by Wong (Wong, F. (1978),Nature (London) 276:76–79). We present new experimental results which show that the relaxation time of the falling phase of bumps is markedly shortened by light-adaptation. Hence the state of light-adaptation has to be taken into account when comparing different experiments. Secondly, we investigate three simple models for the mechanism of channel opening and closing, and conclude that an agreement of the mean open time of single channels, the relaxation time of the falling phase of bumps, and the inverse characteristic frequency of the noise power spectrum cannot be expected.     

Mathematical modeling of capillary formation and development in tumor angiogenesis: penetration into the stroma

The purpose of this paper is to present a mathematical model for the tumor vascularization theory of tumor growth proposed by Judah Folkman in the early 1970s and subsequently established experimentally by him and his coworkers [Ausprunk, D. H. and J. Folkman (1977) Migration and proliferation of endothelial cells in performed and newly formed blood vessels during tumor angiogenesis, Microvasc Res., 14, 53–65; Brem, S., B. A. Preis, ScD. Langer, B. A. Brem and J. Folkman (1997) Inhibition of neovascularization by an extract derived from vitreous Am. J. Opthalmol., 84, 323–328; Folkman, J. (1976) The vascularization of tumors, Sci. Am., 234, 58–64; Gimbrone, M. A. Jr, R. S. Cotran, S. B. Leapman and J. Folkman (1974) Tumor growth and neovascularization: an experimental model using the rabbit cornea, J. Nat. Cancer Inst., 52, 413–419]. In the simplest version of this model, an avascular tumor secretes a tumor growth factor (TGF) which is transported across an extracellular matrix (ECM) to a neighboring vasculature where it stimulates endothelial cells to produce a protease that acts as a catalyst to degrade the fibronectin of the capillary wall and the ECM. The endothelial cells then move up the TGF gradient back to the tumor, proliferating and forming a new capillary network. In the model presented here, we include two mechanisms for the action of angiostatin. In the first mechanism, substantiated experimentally, the angiostatin acts as a protease inhibitor. A second mechanism for the production of protease inhibitor from angiostatin by endothelial cells is proposed to be of Michaelis-Menten type. Mathematically, this mechanism includes the former as a subcase. Our model is different from other attempts to model the process of tumor angiogenesis in that it focuses (1) on the biochemistry of the process at the level of the cell; (2) the movement of the cells is based on the theory of reinforced random walks; (3) standard transport equations for the diffusion of molecular species in porous media. One consequence of our numerical simulations is that we obtain very good computational agreement with the time of the onset of vascularization and the rate of capillary tip growth observed in rabbit cornea experiments [Ausprunk, D. H. and J. Folkman (1977) Migration and proliferation of endothelial cells in performed and newly formed blood vessels during tumor angiogenesis, Microvasc Res., 14, 73–65; Brem, S., B. A. Preis, ScD. Langer, B. A. Brem and J. Folkman (1997) Inhibition of neovascularization by an extract derived from vitreous Am. J. Opthalmol., 84, 323–328; Folkman, J. (1976) The vascularization of tumors, Sci. Am., 234, 58–64; Gimbrone, M. A. Jr, R. S. Cotran, S. B. Leapman and J. Folkman (1974) Tumor growth and neovascularization: An experimental model using the rabbit cornea, J. Nat. Cancer Inst., 52, 413–419]. Furthermore, our numerical experiments agree with the observation that the tip of a growing capillary accelerates as it approaches the tumor [Folkman, J. (1976) The vascularization of tumors, Sci. Am., 234, 58–64]. An erratum to this article is available at .     

Interactions of progesterone with D-amino acid oxidase—different effects on apo- and holo-enzyme

A simple method using charcoal treatment was developed for the preparation of apo-D-amino acid oxidase from rat kidney homogenates. This apo-D-amino acid oxidase was used to study the effect of progesterone on the apo- and holo-enzyme. Progesterone inhibited the activity of D-amino acid oxidase, when the apo-enzyme, preincubated with saturating amounts of FAD was used; this effect varied with FAD concentration. Progesterone did not inhibit the activity when added to a mixture of non-preincubated apo-enzyme and FAD; this suggests that progesterone has different effects on apo- and holo D-amino acid oxidase. Preliminary report presented at the V International Congress of Hormonal Steroids, 29 Oct–4 Nov. 1978, New Delhi.J. Steroid Biochem. 9, 832, (abstract 94) 1978.     

Persistence and global stability in a predator-prey model consisting of three prey genotypes with fertility differences

A model of a predator-prey interaction, where the prey population consists of three genotypes with random mating and continuous, nonlinear birth and death processes with fertility differences, is proposed. Sufficiency conditions giving the existence of a globally stable equilibrium on one of the coordinate planes are given. This extends results of Freedman and Waltman [J. Math. Biol. 6, 367–374 (1978) andRocky Mountain J. Math. 12, 779–784 (1982)]. In addition, conditions are derived which guarantee the persistence of all components of the populations. Research in part is from a Ph.D. thesis submitted to the Faculty of Graduate Studies and Research of the University of Alberta. Research partially supported by the Natural Sciences and Engineering Research Council of Canada, grant no. NSERC A4813.     

Besprechungen/Reviews

Book reviewed in this article: Veselovský, Z. (1978): Beobachtungen zu Biologie und Verhalten des Groz?en Kragenlaubenvogels Baptista, L. F. (1978): Territorial, courtship and duett songs of the Cuban Grassquit Berg-Schlosser, G. (1978): Schneepaddeln, eine Verhaltensweise des Bergfinken Russell, P. , und J. H. Balda (1978): The care of young Piñon Jays Güttinger, H. R. (1978): Verwandtschaftsbeziehungen und Gesangsaufbau beim Stieglitz Immelmann, K., H.-H. Kalberlah, P. Rausch und A. Stahnke (1978): Sexuelle Prägung als möglicher Faktor innerartlicher Isolation beim Zebrafinken Thielcke, G., K. Wüstenberg und P. H. Becker (1978): Reaktionen von Zilp-zalp und Fitis Csiscáky, M. (1978): Über den Gesang der Feldlerche Pflumm, W. (1978): Zur Nahrungsaufnahme des Fichtenkreuzschnabels Löhrl, H. (1978): Das “Nachstürzen” — eine reflexartige Reaktion, entfallene Beute wieder zu erlangen Reddig, E. (1978): Der Ausdrucksflug der Bekassine Becker, P. H. (1978): Der Einfluz? des Lernens auf einfache und komplexe Gesangsstrophen der Sumpfmeise Berthold, P. , und G. Zink ed. (1977): Ökophysiologische Probleme in der Ornithologie Thiele, H. U. (1977): Carabid beetles in their environments Mostofsky, D. I. , ed. (1978): The behavior of fish and other aquatic animals Snow, D. W. (1976): The Web of Adaptation (Das Netzwerk der Anpassungen) Remmert, H. (1978): Ökologie. Ein Lehrbuch Christiansen, F. B. , und T. M. Fenchel (1977): Theories of populations in biological communities Weber, E. (1974): Einführung in die Faktorenanalyse     

Age at first coitus and choice of contraceptive method: Preliminary report on a study of factors related to cervical neoplasia

MUTATIONS: BIOLOGY AND SOCIETY: Edited by D. N. Walcher, N. Kretchmer, and H. L. Barnett. Masson Publishing USA Inc., 1978. 418 pp. $24.50

THE ETHICS OF SOCIAL INTERVENTION: Edited by Gordon Bermant, Herbert C. Kelman, and Donald P. Warwick. Halsted Press (Wiley), New York, 1978. 431 pp. $18.50.

HUMAN MIGRATION: PATTERNS AND POLICIES: Edited by William H. McNeill and Ruth S. Adams. Indiana University Press, Bloomington, 1978.     

两种免疫磁珠分离法分选小鼠骨髓粒-单核祖细胞的效率比较

摘要 目的：提取小鼠骨髓细胞（bone marrow cell, BMC）,用两种不同的免疫磁珠分离（magnetic activated cell sorting, MACS）试剂盒从小鼠BMC中分选提纯粒-单核祖细胞（granulocyte-monocyte progenitor, GMP）,比较这两种免疫磁珠的分选效率。方法：从小鼠股骨和胫骨中提取BMC,通过两种不同的MACS试剂盒,即Lineage阳性细胞清除试剂盒和CD117阳性细胞分选试剂盒,分别得到Lineage-细胞群和CD117⁺细胞群,用代表GMP细胞表面标志物的荧光抗体标记,孵育后通过流式细胞荧光分选技术得到GMP细胞,并且对比得到GMP细胞的效率。结果：每2只野生型C57BL/6J小鼠可共收集骨髓细胞（7.02±1.24）×10⁷个,细胞活力为（91.86±5.24）%。经过Lineage阳性细胞清除试剂盒得到的细胞数量为（5.71±2.86）×10⁶个;经过CD117阳性细胞分选试剂盒得到的细胞数量为（2.70±0.56）×10⁶个。Lineage磁珠分选纯化得到的GMP细胞数占总细胞数的比例为（10.90±1.37）%,CD117磁珠分选纯化得到的GMP细胞数占总细胞数的比例为（4.83±2.08）%。结论：Lineage阳性细胞清除试剂盒能更有效分选小鼠骨髓细胞中的粒-单核祖细胞。     

Triaminopyrimidinium (TAP+) blocks luminal membrane K conductance inNecturus gallbladder epithelium

Summary The effect of triaminopyrimidinium (TAP⁺) on the apical membrane ofNecturus gallbladder epithelial cells was investigated with intracellular microelectrode techniques. TAP⁺, added to the mucosal bathing solution only, produced the following effects (all rapid and reversible): (i) cell depolarization, (ii) increase of apical membrane resistance, and (iii) decrease of the apical membrane potential change produced by K for Na substitution on the mucosal side. These results can be explained by a decrease of apical membrane K conductance. The paracellular effects of TAP⁺ were similar to the ones previously described by Moreno (J.H. Moreno, 1974;Nature (London) 251:150; J.H. Moreno, 1975,J. Gen. Physiol. 66:97). These results indicate that the change of transepithelial potential produced by TAP⁺ cannot be ascribed solely to its effect on the paracellular pathway.     

Halolysin SptA有助于嗜盐古菌Natrinema sp.J7-2长期生存

【背景】嗜盐古菌可以在盐沉积物中存活长达几百万年,是著名的长寿菌。许多嗜盐古菌分泌胞外蛋白酶,大多数分泌的胞外蛋白酶被称为Halolysin,具有以下特征：属于枯草杆菌蛋白酶类蛋白酶;在胞内折叠后经Tat途径高效分泌至胞外;可自加工形成成熟酶;尤其在天然宿主中大多数Halolysin在对数生长后期表达并在稳定期达到最高水平。目前Halolysin的酶学性质、加工成熟及分泌机制已被广泛研究,然而其生理功能的研究较少。Halolysin SptA是嗜盐古菌Natrinema sp.J7-2的主要胞外蛋白酶,前期研究发现多个顺式调控元件协同调节SptA的生长期依赖性表达,使SptA参与J7-2菌株不同生长期之间的转变,而且在衰亡期之后SptA有助于J7-2菌株继续生存。【目的】研究Halolysin SptA对Natrinema sp.J7-2长期生存的作用。【方法】将J7-2菌株和突变体ΔsptA1分别在寡营养、无外源营养物质（液体）及营养丰富（固体）条件下长期培养,通过比较二者的生长、生存和SptA的表达分泌情况进一步探讨SptA的作用。【结果】J7-2菌株在寡营养条件下产生更多SptA,培养后期（33 d） J7-2菌株活细胞数显著高于ΔsptA1。在无外源营养物质情况下长期温育,J7-2菌株和ΔsptA1经历多次细胞分裂和细胞死亡,在延长温育期间（73—200 d）存活的J7-2菌株细胞数量均显著多于存活的ΔsptA1细胞数量。在营养丰富的固体平板上培养的后期（160 d）,由于营养物质消耗,J7-2菌株通过SptA吸收和利用来源于死细胞蛋白的降解产物,帮助其群体长期生存。【结论】SptA介导的细胞死亡和死细胞蛋白降解,促进J7-2菌株利用来源于死细胞的营养物质,从而有助于菌株群体在营养缺乏条件下长期存活。本研究提供了关于Halolysin生理作用的新见解。     

Book Reviews

Psychobiology: The Biological Bases of Behavior Pp. 382, illustrated. New York: Scientific American, 1967. 70s. (cloth), 40s. (paper). Reviewed by O. Lowenstein

Organisation in Plants W. M. M. BARON Pp. vi+218, 117 figs. London: Edward Arnold Ltd., 2nd ed., 1967.18s. (paper), 30s. (boards). Reviewed by J. W. Hannay

A First Biology ERIC SPRINGTHORPE Pp. 103. London: Longmans, Green & Co. Ltd., 1967. 10s. 6d. Reviewed by J. A. Barker

The Biology of Lichens MASON E. HALE, JR. Pp. viii + 176, 60 figs, 15 plates. London: Edward Arnold Ltd., 1967. 42s. Reviewed by K. A. Kershaw

Experiments in the Study of Biology J. J. W. BAKER, G. E. ALLEN, E. GAGE and S. K. WEBSTER Pp. 58. London: Addison-Wesley, 1967. Reviewed by C. F. Stoneman

Microbiological Methods C. H. COLLINS Pp. xii+404, illustrated. London: Butterworths, 2nd ed. 1967. 62s. Reviewed by N. J. Butler

The New Microbiology Ed. JOHN E. FLYNN New York: McGraw Hill Book Co., 1966. Reviewed by W. Howard Hughes

,i>Pergamon Programmed Texts Introduction to Genetics: Science of Heredity A. J. S. MCMILLAN Pp. 410, 64 figs, 6 plates. 1966. J. Audrey Stretch

An Introduction to Biochemistry Vol. 1 A. J. S. MCMILLAN Pp. 208. 1966. J. Audrey Stretch

Biology, Vol. 1 A. VERRINDER Pp. 274, 126 figs. 1966. Oxford: Pergamon Press. Commonwealth and International Library. 25s. (flexi-cover), 35s. (hard cover). J. Audrey Stretch

Grasses JAMES GROVES Published by the School Natural History Society, 1966, and obtainable from M. J. Wootton, Esq., 19A King's Gardens, Cranham, Upminster, Essex. 3s.

Biology Teaching in Schools Involving Experiment or Demonstration with Animals or with Pupils Compiled by J. J. BRYANT The Association for Science Education, 1967. 2s. 9d.

Handbook of Marine Biology for Borth, Cardiganshire A compilation of results and work completed by members of King Edward's School, Birmingham. Obtainable from the School. 6s. 6d.

Clarendon Biographies (16) Charles Darwin R. C. OLBY Pp. 64, 3 figs, 12 plates. London; Oxford University Press, 1967. 9s. 6d. (boards), 5s. (limp).

New Questions in O-Level Biology (Book 2) Plants and Invertebrates J. J. HEAD Pp. 70, illustrated. London: Oliver & Boyd, 1967. 6s. (Teachers' guide. Pp. 32. 5s.)

Revision Exercises in Biology J. D. MAUNDER and C. JOHNSTON Pp. xiii + 130, illustrated. Oxford: Pergamon Press, 1967. 8s. 6d.     

A note on regression to the mean

Sex‐related Cognitive Differences: By Julia A. Sherman. Charles C Thomas, Springfield, Illinois, 1978. 262 pp. Cloth, $16.25; paper, $12.25.

Kinometrics: Determinants of So‐cioeconomic Success Within and Between Families. Edited by Paul Taubman. North‐Holland Publishing Company, Amsterdam, 1977. $28.25

Nutrition and Human Reproduction: Edited by W. Henry Mosley. Plenum Publishing Corporation, New York, 1978. 526 pp. $42.50.

Manual of the International Statistical Classification of Diseases, Injuries, and Causes of Death, Volume 1: World Health Organization, 1977. 777 pp. $12.00 (hardbound). (Also to be published in French, Spanish, and Russian.)

Women in Jamaica: Patterns of Reproduction and Family: By George W. Roberts and Sonja A. Sinclair. KTO Press, New York, 1978. $16.00.     

Uptake of Archaeobacterial Liposomes and Conventional Liposomes by Phagocytic Cells

Abstract

Liposomes in the 200 nm size range were prepared from the ether lipids extracted from various Archaeobacteria (coined archaeosomes), and from conventional lipids. The entrapment of peroxidase or carboxyfluorescein was used to compare the in vitro uptake of various liposomes by murine peritoneal macrophages, J774A.1 macrophages and several non phagocytic cell lines. While liposomes composed of ester lipids dipalmitoylphosphatidylcholine, or dimyristoylphosphatidylcholine: dimyristoylphosphatidylglycerol: cholesterol (1.8:0.2:1.5, molar ratio) were taken up by macrophage species, the uptake of archaeosomes was 3 to 53 times greater. Uptake by non phagocytic HEp-2, HeLa, and EJ/28 cells was considerably less. Evidence from time-course studies using cytochalasins B+D, sub-optimal temperature or formaldehyde treatments of macrophages, indicated that the archaeosomes lost structural integrity following internalization within the J774A. 1 phagocytic cells. No cytotoxicity was observed in viability or growth assays with J774A. 1 cells, using high doses of three representative types of archaeosomes and one type of conventional-liposome. Therefore, archaeosomes may be well suited to applications where phagocytic cells are a target site.     

What is pea legumin — Is it glycosylated?

Since there is some question as to whether or not legumin is glycosylated, this storage protein was isolated by various procedures from developing cotyledons of Pisum sativum L. supplied with [¹⁴C]-labeled glucosamine and analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis. Legumin isolated by the classical method of Danielsson [(1949) Biochem. J. 44, 387–400] a procedure in which globulins extracted with a buffered salt solution are precipitated with ammonium sulfate (70% saturation) and legumin separated from vicilin by isoelectric precipitation, was labeled. The glucosamine incorporated into legumin was associated with low-molecular-weight polypeptides. In contrast, legumin isolated by the method of Casey [(1979) Biochem. J. 177, 509–520], a procedure where legumin is prepared by zonal isoelectric precipitation from globulins precipitated with 40–70% ammonium sulfate, was not labeled. However, the globulin fraction precipitated with 40% ammonium sulfate was labeled and the radioactive glucosamine was associated with low-molecular-weight polypeptides. Legumin isolated from protein bodies [Thomson et al. (1978) Aust. J. Plant Physiol. 5, 263–279] was not extensively labeled. However, the saltinsoluble fraction of protein body extracts was labeled and the radioactivity was associated with low-molecular-weight polypeptides. These results indicate that protein bodies contain a glycoprotein of low-molecular-weight that co-purifies with legumin isolated by the method of Danielsson but that is discarded when isolation methods developed more recently are used.     

Sawhorse-type diruthenium tetracarbonyl complexes containing porphyrin-derived ligands as highly selective photosensitizers for female reproductive cancer cells

Diruthenium tetracarbonyl complexes of the type [Ru₂(CO)₄(μ₂-η²-O₂CR)₂L₂] containing a Ru–Ru backbone with four equatorial carbonyl ligands, two carboxylato bridges, and two axial two-electron ligands in a sawhorse-like geometry have been synthesized with porphyrin-derived substituents in the axial ligands [1: R is CH₃, L is 5-(4-pyridyl)-10,15,20-triphenyl-21,23H-porphyrin], in the bridging carboxylato ligands [2: RCO₂H is 5-(4-carboxyphenyl)-10,15,20-triphenyl-21,23H-porphyrin, L is PPh₃; 3: RCO₂H is 5-(4-carboxyphenyl)-10,15,20-triphenyl-21,23H-porphyrin, L is 1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane], or in both positions [4: RCO₂H is 5-(4-carboxyphenyl)-10,15,20-triphenyl-21,23H-porphyrin, L is 5-(4-pyridyl)-10,15,20-triphenyl-21,23H-porphyrin]. Compounds 1–3 were assessed on different types of human cancer cells and normal cells. Their uptake by cells was quantified by fluorescence and checked by fluorescence microscopy. These compounds were taken up by human HeLa cervix and A2780 and Ovcar ovarian carcinoma cells but not by normal cells and other cancer cell lines (A549 pulmonary, Me300 melanoma, PC3 and LnCap prostate, KB head and neck, MDAMB231 and MCF7 breast, or HT29 colon cancer cells). The compounds demonstrated no cytotoxicity in the absence of laser irradiation but exhibited good phototoxicities in HeLa and A2780 cells when exposed to laser light at 652 nm, displaying an LD₅₀ between 1.5 and 6.5 J/cm² in these two cell lines and more than 15 J/cm² for the others. Thus, these types of porphyric compound present specificity for cancer cell lines of the female reproductive system and not for normal cells; thus being promising new organometallic photosensitizers.     

Effect of turgor pressure on water permeability ofAllium cepa epidermis cell membranes

Summary Using onion epidermis layer a very accurate method for measuring the permeability of epidermis cells to water was standardized. In this method a 1.4 cm diameter epidermis disc was soaked in tritiated water (500 Ci/ml) for about 1 hr. Next the disc was mounted in a specially designed elution chamber where it was held flat and washed on the noncuticular side with ordinary water. A constant flow rate, high enough to minimize unstirred layer effect, was used. Permeability was calculated in the usual way after separating different exponentials from the efflux curve of tritiated water. Turgor pressure of the cell was regulated by soaking the disc in mannitol solutions containing tritiated water and washing it in the chamber with same concentration mannitol solution containing no radioactivity. Water permeability values were found to decrease less than 8% when the turgor pressure was decreased from 8 atm (full turgor) to zero. Turgor pressure had no significant effect on the water permeability of onion epidermal cells. Our results are contradictory to the findings of Zimmerman and Steudle (1974,J. Membrane Biol. 16:331) but are similar to the findings of Tazawa and Kamiya (1966,Aust. J. Biol. Sci. 19:339) and Kiyosawa and Tazawa (1972,Protoplasma 74:257).     

调节TREK1对小鼠海马神经干细胞增殖和BDNF表达的影响

目的:观察调节TWIK相关的K+通道1(TREK1)对小鼠海马神经干细胞增殖和脑源性神经营养因子(brain derived neurotrophic factor,BDNF)表达的影响。方法:从孕10.5 d C57bl/6J小鼠胚胎海马中分离出神经干细胞并培养,待细胞达到70%～80%融合后,对细胞进行慢病毒干预,细胞分为sham组,Ctrl组(转染对照病毒),Plenti-TREK-1组(转染携带TREK1高表达载体病毒)和sh-TREK-1组(转染携带TREK1-shRNA病毒)。采用CCK-8法检测病毒干预后3天和7天各组神经干细胞的细胞活力,采用q RT-PCR检测病毒干预后7天各组神经干细胞TREK-1基因表达情况,并通过Elisa检测各组神经干细胞上清液BDNF表达水平。结果:与sham组相比较,(1)Plenti-TREK-1组TREK1基因表达上调,神经干细胞的神经球体积减小,细胞活力降低,细胞增殖减少,细胞上清BDNF水平下降;(2)sh-TREK-1组TREK1基因表达下调,神经干细胞的神经球体积增加,细胞活力增高,细胞增殖增加,细胞上清BDNF水平上调;(3)上述各项指标Ctrl组与sham组之间无统计学差异。结论:神经干细胞的增殖与TREK1通道密切相关,上调TREK-1可以抑制神经干细胞增殖及其BDNF的表达水平;下调TREK-1则可以促进神经干细胞增殖并上调其BDNF的表达水平。     

Besprechungen/Review

Book reviewed in this article: Zeitschriften/Periodicals: Demars, Ch., und M. Goustard (1978: Le “grand chant” d'Hylobates conclor leucogenys. Comparsion avec les émissions sonores homologues d'H. concolor gabriellae et d'H. Klossii (Iles Mentawei, Ouest Sumatra) (Vergleich der Gesänge zweier Unterarten von Schopfgibbons und des Zwergsiamang). Zeitschriften/Periodicals: Polsky, R. H. (1978): The ontogeny of predatory behaviour in the Golden Hamster (Mesocricetus a. suratus). IV. Effects of prolonged exposure, iti, size of prey and selective breeding (Die Entwickliung des Beutefangverhaltens beim Goldhamster. IV. Welchen Einfluß haben längeres Zusammensein mit der Beute, deren Größe, Zeitabstände der Versuche und Genotyp?) Zeitschriften/Periodicals: Fernö, A, (1978). The effect of social isolation on the aggressive and sexual behaviour in a Chichlid Fish, Haplochromis burtoni (Wie beeinflußt Absonderung von Artgenossen das Angriffs- und Paarungsverhalten des Buntbarschs H. b.). Zeitschriften/Periodicals: Lazarus, J., und I. R. Inglis (1978): The breeding behaviour of the Pinkfooted Goose: Parental care and vigilant behaviour during the fledging period (Das Brutverhalten der Kurzschnabelgans: Fursorge und Wachsamkeit der Eltern wahrend der Fuhrungszeit). Zeitschriften/Periodicals: Brémond, J. -C. (1978): Acoustic competition between the song of the Wren (Troglodytes troglodytes) and the songs of other species (Wird beim Zaunköning das Erkennen des Artgesangs durch die Gesänge anderer Arten gestört?) Zeitschriften/Periodicals: Feyereisen, P., und Ch. Blondiau (1978): Comportements de toilettage et activation chez le Rat Balnc (Über den Einfluß von Außenreizen auf das Putzverhalten von Ratten). Zeitschriften/Periodicals: Hennessy, D. F., und D. H. Owings (1978): Snake species discrimination and the role of olfactory cues in the snake-directed behavior of the California Ground Squirrel (Unterscheidung von Schlangenarten und die Bedeutung von Geruchsreizen für das Verhalten Kalifornischer Backenhörnchen gegen Schlangen). Behaviour 65, 115-124. Zeitschriften/Periodicals: Itzkowitz, M. (1978): Group organization of a territorial Damselfish, Eupomacentvus planifrons (Soziale Organisation des territorialen Korallenbarschs Eu. p.). Zeitschriften/Periodicals: Hay, Th. F. (1978): Filial imprinting in the Convict Cichlid Fish Cichlusoma nigrofasciatum (Prägung der Nachfolgcreaktion bei dem Buntbarsch C. n.). Zeitschriften/Periodicals: Kavanau, J. L. (1978): Compulsory regime and control of environment in animal behaviour IV. Light level preferences of Cactus Mice, Pevomyscur evemicus (Erzwungene und selbstbestimmte Tatigkeitseinteilung im Tagesablauf IV. Vorzugshelligkeiten von Kaktusmausen). Zeitschriften/Periodicals: Hyatt, G. W., und M. Slamon 91978): Combat in the Fiddler Crabs Uca pugiltor and U. pugnax: A Quantitative analysis (Kämpfende Winkerkrabben: Eine quantitiative Analyse). Zeitschriften/Periodicals: Walther, F. R. (1978): Quantitative and functional variations of certain behaviour patterns in male Thomson's Gazelle of different social status (Häufigheit und wechselnde Funktionen bestimmter Verhaltensweisen beimännlichen Thomson-Gazellen in verschiedener sozialer Stellung). Zeitschriften/Periodicals: Güttinger, H. R., J. Wolffgramm und F. Thimm (1978): The relationship between species specific song programs and individual learning in songbirds: A study of individual variation in songs of Canaries, Greenfinches, and hybrids between the two species (Arttypische Gesangsprogramme und Lernen bei Singvögeln: Eine Untersuchung der individuellen Variabilität der Gesänge von Kanarienvögeln, Grünlingen und deren Bastarden). Zeitschriften/Periodicals: Kovach, J. K. (1978): Color preferences in Quail chicks: Generalization of the effects of genetic selection (Farbenwahlen unerfahrener Wachtelküken: Ergebnisse künstlicher Selektion). Zeitschriften/Periodicals: Lillehei, R. A., und Ch. T. snowdon (1978): Individual and situational differences in the vocalizations of young Stumptail Macapues (Macaca arctoides) (Persönliche und situationsbedingte Unterschiede in den Lautäaßerungen junger Bärenmakaken). Zeitschriften/Periodicals: Payne, R. B. (1978): Microgeographic variation in songs of Splendid Sunbirds Necturiniu coccinigaster: Population phenetics, habitats, and song dialects (Mikrogeographische Variation der Gesänge von N. C.: Populationsphaenetik, Lebensräume und Dialekte). Zeitschriften/Periodicals: Bailey, K. (1978): Flehmen in the Ring-Tailed Lemur (Lemur catta) (Flchmen beim Katta). Zeitschriften/Periodicals: Horn, E., B. Greiner und I. Horn (1979): The effect of ACTH on habituation of the turning reaction in the toad Bufo bufo L. (Die Wirkung von Corticotropin auf das Abgewöhnen der Zuwendung zu Beuteattrappen bei der Erdkröte). J. Comp. Zeitschriften/Periodicals: Egremont, P., und M. Rothschild (1979): The calulating cormorants (Zählende Kormorane). Zeitschriften/Periodicals: Chauvin-Muckensturm, B. (1974): Y a-t-il utilisation de signaux appris comme moyen de communication chez le Pic Epeiche? (Kann der Buntspecht erlernte Zeichen zur Mitteilung verwenden?). Bücher: Buchholtz , Chr. (1973): Das Lernen bei Tieren. Verhaltensänderungen durch Erfahrung. Bücher: Skinner , B. F. (1973): Wissenschaft und menschliches Verhalten (Science and human behavior, aus dem Amerikanischen von E. Ortmann).