Reviews of publications

Principles of Crop Improvement, by N. W. Simmonds
Marine Organisms – Genetics, Ecology & Evolution, edited by B. Battaglia & J. A. Beardrnore
Arthropod Phytogeny, edited by A. P. Gupta. Van Nostrand Reinhold
Field Guide to the Land Snails of Britain and North-west Europe, by M. P. Kernev & R. A. D. Cameron; illustrated by Gordon Riley
Key to the Fishes of Northern Europe, by Alwync Wheeler; illustrated by Peter Stebbing; maps by F. Rodney Fraser
Penguin Nature Guides: The Biology of Flowers, by Eigil Holm; illustrated by Thomas BredsdorfT; translated by Joan Tate; edited & adapted by Ronald Melville
Penguin Nature Guides: Orchids of Northern Europe, by Sven Nilsson; illustrated by Bo Mossberg; edited & adapted by P. Francis Hunt
A New Look at the Dinosaurs, by Alan Charig. Heinemann     

Differential antimutagenic effects of caffeine and the protease inhibitor antipain on mutagenesis by various mutagens in Escherichia coli

The effects of caffeine (2 mg/ml) and the protease inhibitor antipain (1.75 mb/ml) in the plating agar medium on the yields of prototrophic revertants induced by 10 mutagens in E. coli uvrA^? strains were tested. Mutagenesis by 4-nitroquinoline 1-oxide was greatly diminished by both caffeine and antipain. UV mutagenesis was decreased moderately by caffeine, and greatly by antipain. X-Ray mutagenesis was decreased very slightly by both caffeine and antipain. Mutagenesis by N-hydroxyurethan was inhibited moderately by caffeine, and greatly by antipain; that by methyl methanesulfonate was inhibited moderately by both caffeine and antipain, and that by N-methyl-N′-nitro-N-nitrosoguanidine wa was not suppressed by caffeine but was inhibited moderately by antipain. Mutagenesis by ethyl methanesulfonate was inhibited greatly by caffeine, but only slightly by antipain. The antimutagenic effect of caffeine was strong on furylfuramide (AF-2) mutagenesis, moderate on that of mitomycin C (tested with B/r type strain) and negligible on that of N-methyl-N-nitrosourea. These diverse antimutagenesis patterns are briefly discussed in relation to the current idea that antipain antimutagenesis is due to inhibition of inducible error-prone repair.     

The Effect of Proteolytic Enzymes on E. coli Phages and on Native Proteins

Lambda coli phage is not inactivated by chymotrypsin, trypsin, or ficin. T₂ phage is slowly inactivated by high concentrations of (α-, β-, γ-, or Δ-chymotrypsin, but not by trypsin or ficin. P₁ phage is slowly inactivated by α-, β-, or γ-chymotrypsin, or ficin, more rapidly by Δ-chymotrypsin, and much more rapidly by trypsin. Crystalline egg albumin, crystalline serum albumin, E. coli nucleoprotein, and yeast nucleoprotein are hydrolyzed slowly by α-chymotrypsin. Yeast nucleoprotein, like P₁ phage, is hydrolyzed more rapidly by Δ-chymotrypsin than by α-chymotrypsin, but not by trypsin or ficin. Neither phages nor native proteins were attacked by papain, carboxypeptidase, deoxyribonuclease, or ribonuclease.     

Bidirectional Ca2+ coupling of mitochondria with the endoplasmic reticulum and regulation of multimodal Ca2+ entries in rat brown adipocytes

How the endoplasmic reticulum (ER) and mitochondria communicate with each other and how they regulate plasmalemmal Ca²⁺ entry were studied in cultured rat brown adipocytes. Cytoplasmic Ca²⁺ or Mg²⁺ and mitochondrial membrane potential were measured by fluorometry. The sustained component of rises in cytoplasmic Ca²⁺ concentration ([Ca²⁺]_i) produced by thapsigargin was abolished by removing extracellular Ca²⁺, depressed by depleting extracellular Na⁺, and enhanced by raising extracellular pH. FCCP, dinitrophenol, and rotenone caused bi- or triphasic rises in [Ca²⁺]_i, in which the first phase was accompanied by mitochondrial depolarization. The FCCP-induced first phase was partially inhibited by oligomycin but not by ruthenium red, cyclosporine A, U-73122, a Ca²⁺-free EGTA solution, and an Na⁺-free solution. The FCCP-induced second phase paralleling mitochondrial repolarization was partially blocked by removing extracellular Ca²⁺ and fully blocked by oligomycin but not by thapsigargin or an Na⁺-deficient solution, was accompanied by a rise in cytoplasmic Mg²⁺ concentration, and was summated with a high pH-induced rise in [Ca²⁺]_i, whereas the extracellular Ca²⁺-independent component was blocked by U-73122 and cyclopiazonic acid. The FCCP-induced third phase was blocked by removing Ca²⁺ but not by thapsigargin, depressed by decreasing Na⁺, and enhanced by raising pH. Cyclopiazonic acid-evoked rises in [Ca²⁺]_i in a Ca²⁺-free solution were depressed after FCCP actions. Thus mitochondrial uncoupling causes Ca²⁺ release, activating Ca²⁺ release from the ER and store-operated Ca²⁺ entry, and directly elicits a novel plasmalemmal Ca²⁺ entry, whereas Ca²⁺ release from the ER activates Ca²⁺ accumulation in, or release from, mitochondria, indicating bidirectional mitochondria-ER couplings in rat brown adipocytes. plasmalemmal calcium entry; calcium release; mitochondrial depolarization; FCCP     

Mediation of a plant response to malformin by ethylene

Malformin and ethylene stimulate abscission of the primary leaves of Phaseolus aureus Roxb. in the dark, and abscission stimulation by both compounds is inhibited by indeleacetic acid and CO₂. Ethylene production by malformin-treated buds is stimulated within 4 hours. and up to 8 days, after treatment. Malformin-induced growth disturbances in P. vulgaris L. and abscission in P. aureus are considered mediated by ethylene. Although root curvatures of Zea mays L. are induced by both malformin and ethylene, and malformin is inhibited by CO₂, ethylene production is not stimulated by malformin. A role of ethylene in root curvatures induced by malformin is neither proposed nor disproved.     

Reviews of publications

Book reviewed in this article: A World Like Our Own—Man and Nature in Madagascar, by Alison Jolly. Vertebrate Limb Regeneration, by H. Wallace. Statistical Methods in Biology, by N. T.J. Bailey Conservation and Evolution, by O. H. Frankel & M. E. Soule Evolution in Age-structured Populations by B. Charlesworth Essential Biology, by Herbert T. Hendrickson Flora Suzakiensis, edited by Biological Laboratory, Imperial Household Phylogenetic Patterns and the Evolutionary Process, by N. Eldredge & J. Cracraft Excursion Flora of the British Isles, by A. R. Clapham, T. G. Tutin & E. F. Warburg Whales, by W. N. Bonner Les Chevaux, Fossiles et Actuels, by V. Eisenmann Freshwater Snails of Africa and their Medical Importance, by David S. Brown Symbiosis in Cell Evolution, by Lynn Margulis Vegetation Dynamics, by J. Miles     

Effects of prostaglandins and catecholamines on rat spleen adenylate cyclase in vitro

The results reported here show some characteristics of adenylate cyclase (EC 4.6.1.1) derived from homogenates of rat spleen, and describe the in vitro stimulation of this enzyme by prostaglandins, nucleotides, and F⁻ under conditions where cyclic nucleotide degradative pathways are effectively inhibited.Particulate fractions from rat spleen homogenates contain high adenylate cyclase activities, and the highest specific activity is recovered in a particulate fraction prepared by low speed (1200 × g) centrifugation. Activity found in all particulate fractions is stimulated by fluoride, prostaglandins E₁ and E₂, catecholamines, and purine nucleotides. No stimulation is caused by prostaglandins F_1α and F_2α. Stimulation by prostaglandin E₁ or E₂ is augmented by GTP and other purine nucleotides, and stimulation by the combination of GTP and prostaglandin E₁ is equal to that caused by optimal fluoride concentrations. Stimulation c caused by L-isoproterenol is additive to that caused by GTP but is not increased by GTP.     

Nematophagous Fungi Associated with Root Galls of Rice Caused by Meloidogyne graminicola and its Control by Arthrobotrys dactyloides and Dactylaria brochopaga

Root galls of rice caused by Meloidogyne graminicola were examined for natural colonization by nematophagous fungi from four fields with different nematode infestations. Old galls from severely infested fields had a higher frequency of Monacrosporium eudermatum and Stylopaga hadra than young galls. The frequency of Arthrobotrys oligospora, Arthrobotrys dactyloides, Dactylaria brochopaga and Monacrosporium gephyropagum was lower. A greater proportion (%) of root galls were colonized by nematophagous fungi in those fields in which rice roots had a greater root gall index. This indicated that disease severity supported the colonization of galls by nematophagous fungi. In vitro predacity tests of four fungi showed that A. dactyloides was most effective in capturing and killing J₂ of Mel. graminicola followed by D. brochopaga and Mon. eudermatum. Application of inocula of A. dactyloides and D. brochopaga in soil infested with Mel. graminicola, respectively, reduced the number of root galls by 86% and of females by 94%, and eggs and juveniles by 94%. The application of these fungi to soil increased plant growth: shoot length by 42.7% and 39.8%, root length by 45.5% and 48.9%, fresh weight of shoot by 59.9% and 56.7% and fresh weight of root by 20.3% and 25.1%, respectively, compared to these parameters for plants grown in nematode‐infested soil.     

THE ACTION OF POTASSIUM CYANIDE AND POTASSIUM FERRICYANIDE ON CERTAIN RESPIRATORY PIGMENTS

The oxygen in hemoglobin is liberated by K₃Fe(CN)₆ and not by KCN, that in hemocyanin by KCN and not by K₃Fe(CN)₆, that in hemerythrin by both, and that in echinochrome by K₃Fe(CN)₆ and not by KCN. The bearing of these results on the nature of the substances involved is discussed.     

Requirement of thiols for activation of coronary arterial guanylate cyclase by glyceryl trinitrate and sodium nitrite possible involvement of S-nitrosothiols

Glyceryl trinitrate specifically required cysteine, whereas NaNO₂ at concentrations less than 10 mM required one of several thiols or ascorbate, to activate soluble guanylate cyclase from bovine coronary artery. However, guanylate cyclase activation by nitroprusside or nitric oxide did not require the addition of thiols or ascorbate. Whereas various thiols enhanced activation by nitropruside, none of the thiols tested enhanced activation by nitric oxide. S-Nitrosocysteine, which is formed when cysteine reacts with either NO₂^? or nitric oxide, was a potent activator of guanylate cyclase. Similarly, micromolar concentrations of the S-nitroso derivatives of penicillamine, GSH and dithiothreitol, prepared by reacting the thiol with nitric oxide, activated guanylate cyclase. Guanylate cyclase activation by S-nitrosothiols resembled that by nitric oxide and nitroprusside in that activation was inhibited by methemoglobin, ferricyanide and methylene blue. Similarly, guanylate cyclase activation by glyceryl trinitrate plus cysteine, and by NaNO₂ plus either a thiol or ascorbate, was inhibited by methemoglobin, ferricyanide and methylene blue. These data suggest that the activation of guanylate cyclase by each of the compounds tested may occur through a common mechanism, perhaps involving nitric oxide. Moreover, these findings suggest that S-nitrosothiols could act as intermediates in the activation of guanylate cyclase by glyceryl trinitrate, NaNO₂ and possibly     

Inhibition of Iron-oxidizing Activity by Bisulfite Ion in Thiobacillus ferrooxidans

Growth of Thiobacillus ferrooxidans on iron- and sulfur-salts media and iron oxidizing activity of this bacterium were strongly inhibited by bisulfite ion. The mechanism of inhibition by bisulfite ion of iron-oxidizing activity was studied with the plasma membrane of T. ferrooxidans AP19-3. The c-type cytochrome in the plasma membrane was reduced by ferrous ion and the cytochrome reduced by Fe²⁺ was oxidized by cytochrome c oxidase in the plasma membrane. In contrast, c-type cytochrome was reduced by bisulfite ion, but it was not oxidized by cytochrome c oxidase in the membrane. Cytochrome c-oxidizing activity was also inhibited by the ion when mammalian cytochrome c was used as an electron donor, suggesting that cytochrome c oxidase, one of the component of iron oxidase, is the site of inhibition by bisulfite ion.     

Macrophage-mediated cytolysis of erythrocytes in the guinea pig. II. Role of oxidative burst products in macrophage cytotoxicity activated by lectins and phorbol ester derivatives

Guinea pig peritoneal macrophages (GPPM) exhibited enhanced production of O₂^? and H₂O₂, and cytolytic activity toward erythrocytes, in response to reagents such as 12-O-tetradecanoyl-phorbol-13-acetate (TPA), its methylated derivative 4-O-MeTPA, Con A, wheat germ agglutinin (WGA), and opsonized zymosan. In order to examine the possible role of oxidative burst products such as O₂^? and H₂O₂ in the cytolytic process, we used reagents and enzymes which influence the balance of O₂^? and H₂O₂ outside and inside the GPPM cells. Macrophage-mediated cytolysis (MMC) of erythrocytes in the presence of the activators and modulators was assessed by ⁵¹Cr release assay. MMC activated by TPA and 4-O-MeTPA was inhibited by scavengers of H₂O₂ such as catalase and α-tocopherol, and was augmented by the catalase inhibitor 3-amino-1,2,4-triazole, and by horseradish peroxidase. TPA- and 4-O-MeTPA-activated MMC was only partially inhibited by the O₂^? scavenger cytochrome c and the enzyme superoxide dismutase and unaffected by cytochalasin D (an inhibitor of phagocytosis). MMC activated by the lectins Con A and WGA was unaffected by the scavengers and enzymes used, but markedly inhibited by cytochalasin D. Activation of MMC by TPA, WGA, and phagocytosis of opsonized zymosan, as well as O₂^? and H₂O₂ generation triggered by these reagents, were markedly inhibited by chlorpromazine. The results indicate that GPPM-mediated cytolysis activated by lectins, phorbol ester derivatives, and phagocytosis of opsonized zymosan, is dependent on the generation of oxidative burst products, mainly H₂O₂. TPA- or 4-O-MeTPA-activated MMC is mainly an extracellular event, while lectin-activated MMC may take place within the macrophages.     

Inhibition of ferricyanide reduction in chloroplast particles by anaerobicity.

The reduction of ferricyanide by spinach and pea chloroplast particles was the same under aerobic or anaerobic conditions. The rate of ferricyanide reduction by these particles uncoupled by ammonium chloride or carboxycyanide p-trifluoromethoxyhydrazone, or $\text{Chlamydomonas reinhardi}$ or $\text{Euglena gracilis}$ particles uncoupled by sonic oscillation, was inhibited by anaerobic conditions. This inhibition by anaerobicity may explain the cessation of the photolysis of water as measured by H₂ production in reconstituted preparations consisting of chloroplast particles, ferredoxin and fully active hydrogenase.     

Activation of Akt/GSK-3β signaling pathway is involved in intermedin1–53 protection against myocardial apoptosis induced by ischemia/reperfusion

Intermedin (IMD) is a novel member of the calcitonin/calcitonin gene-related peptide family. We investigated the cardioprotective mechanism of IMD_1–53 in the in vivo rat model of myocardial ischemia/reperfusion (I/R) injury and in vitro primary neonatal cardiomyocyte model of hypoxia/reoxygenation (H/R). Myocardial infarct size was measured by 2,3,5-triphenyl tetrazolium chloride staining. Cardiomyocyte viability was determined by trypan blue staining, cell injury by lactate dehydrogenase (LDH) leakage, and cardiomyocyte apoptosis by terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling assay, Hoechst staining, gel electrophoresis and caspase 3 activity. The translocation of mitochondrial cytochrome c of myocardia and expression of apoptosis-related factors Bcl-2 and Bax, phosphorylated Akt and phosphorylated GSK-3β were determined by western blot analysis. IMD_1–53 (20 nmol/kg) limited the myocardial infarct size in rats with I/R; the infarct size was decreased by 54%, the apoptotic index by 30%, and caspase 3 activity by 32%; and the translocation of cytochrome c from mitochondria to cytosol was attenuated. IMD_1–53 increased the mRNA and protein expression of Bcl-2 and ratio of Bcl-2 to Bax by 81 and 261%, respectively. IMD_1–53 (1 × 10⁻⁷ mol/L) inhibited the H/R effect in cardiomyocytes by reducing cell death by 43% and LDH leakage by 16%; diminishing cellular apoptosis; decreasing caspase 3 activity by 50%; and increasing the phosphorylated Akt and GSK-3β by 41 and 90%, respectively. The cytoprotection of IMD_1–53 was abolished with LY294002, a PI3K inhibitor. In conclusion, IMD_1–53 exerts cardioprotective effect against myocardial I/R injury through the activation of the Akt/GSK-3β signaling pathway to inhibit mitochondria-mediated myocardial apoptosis.     

Prostanoid synthesis by human umbilical artery

A discrepancy between published values of PGI₂ production by human umbilical artery measured by platelet bioassay, compared with values of 6-oxo-PGF_1α by radioimmunoassay, raised the possibility that another anti-aggregatory prostanoid was produced by this tissue. To test this hypothesis, umbilical artery rings were incubated in buffer and PGI₂ determined by platelet bioassay and by a more specific radioimmunoassay based on comparison of 6-oxo-PGF_1α in hydrolysed and non-hydrolysed samples. 6-oxo-PGF_1a, PGF_2α and TXB₂ were also measured by gas chromatography negative ion chemical ionisation mass spectrometry. PGI₂ concentrations by radioimmunoassay and bioassay were significantly correlated (r = 0.92, p < 0.01). There was no difference between them, disproving the presence of an additional antiaggregatory substance. PGI₂ production determined by bioassay (mean 1.21 ng/mg wet weight/h, range 0.59–1.53 ng/mg/h) differed from previously reported values (range 70–325 ng/mg/h). 6-oxo-PGF_1α concentrations were confirmed by gas chromatography negative ion chemical ionisation mass spectrometry. Previous determinations of PGI₂ production by this tissue overestimated it by approximately 100 times.     

Reviews of publications

Book reviewed in this article: Reproduction of Marine Invertebrates. Vol. VI. Echinoderms and Lophophorates, edited by A. C. Giese, J. S. Pearse and V. B. Pearse. Pacific Grove, California, U.S.A. The Butterflies of Kenya and their Natural History, by T. B. Larsen. The Land and Freshwater Molluscs of Suffolk, by I. J. Killeen. Ipswich, U.K. Flycatcher. Memoirs of an Amateur Entomologist by K. A. Spencer. Ecosystems of the World 24. Intertidal and Littoral Ecosystems, edited by A. C. Mathieson and P. H. Nienhuis. Revision of the Northeast Atlantic and Mediterranean Stylasteridae (Cnidaria: Hydrozoa), by Helmut Zibrowius and Stephen D. Cairns. Paris: Mémoires du Musée Nationale d'Histoire Naturellee, 1992. Animals and Disease. An Introduction to the History of Comparative Medicine, by L. Wilkinson. The Inevitable Bond. Examining Scientist-Animal Interactions, edited by H. Davis and D. Balfour. Martin Lister's English Spiders (1678), edited by J. Parker and B. Harley (translated by M. Davies and B. Harley)). The Ecology of Fishes on Coral Reefs, edited by P. F. Sale. San Diego, USA: The Lepidoptera: Form, Function and Diversity, by M. J. Scoble. Bats. A Community Perspective, by J. S. Findley. The Insects of Australia. A textbook for students and research workers, Commonwealth Scientific and Industrial Research Organisation. Second Edition. Botanical monkeys, by E. J. H. Corner. The Biology of Millipedes, by S. P. Hopkin and H. J. Read. Mammals in the Palaearctic Desert: Status and Trends in the Sahara-Gobian Region, edited by J. A. McNeely and V. M. Neronov. Coelenterate Biology: Recent Research on Cnidaria and Ctenophora, edited by R. B. Williams, P. F. S. Cornelius, R. G. Hughes and E. A. Robson. Dordrecht, The Netherlands: Kluwer Academic Publishers, 1991. Animal Behaviour, 4th ed., by A. Manning and M. S. Dawkins. Weevils, Naturalists' Handbook 16, by M. G. Morris. Insects on Cabbage and Oilseed Rape. Naturalists' Handbooks 18, by W. D. J. Kirk.     

Effects of structural heterogeneity provided by the floating macrophyte <Emphasis Type="Italic">Eichhornia azurea</Emphasis> on the predation efficiency and habitat use of the small Neotropical fish <Emphasis Type="Italic">Moenkhausia sanctaefilomenae</Emphasis>

Macrophytes have a fundamental structuring role in aquatic environments. Several authors have suggested that trophic interactions are particularly mediated by aquatic plants. In the current article, we evaluated the effects of the structural heterogeneity provided by Eichhornia azurea (Kunth) roots on predation and habitat use by the small fish Moenkhausia sanctaefilomenae (Steindachner). We tested the hypotheses that (i) high structural heterogeneity protects macroinvertebrates against predation by M. sanctaefilomenae; (ii) distinct prey types are differently protected by the refuge provided by roots; and (iii) the behavior of M. sanctaefilomenae is affected by the structural heterogeneity provided by macrophyte roots. To test these hypotheses, we performed an experiment in 20 l aquaria in which macroinvertebrates (Cypricercus sp. and Chironomus sp.) were exposed to M. sanctaefilomenae predation for 4 h under three structural heterogeneities, represented by different root densities. High structural heterogeneity protected macroinvertebrates against predation. Additionally, E. azurea roots similarly protected different prey species. The macrophyte spatial structure substantially changed the habitat use of M. sanctaefilomenae. In general, our results corroborated the hypothesis that the structural heterogeneity provided by E. azurea roots significantly affects predation and habitat use by M. sanctaefilomenae. Handling editor: S. Declerck     

The effect of buffers and chelators on the reaction of luminol with Fenton's reagent near neutral pH

The chemiluminescence of the system luminol +Fe²⁺ + H₂O₂ was measured in aqueous buffer at pH 7.2. In veronal (5,5-diethybarbiturate) buffer, the luminescence is strongly quenched by ethanol and mannitol, but only weakly by t-butanol, benzoate and superoxide dismutase (SOD); complexing Fe²⁺ with 1,10-phenanthroline or 2,2′-dipyridyl causes a decrease of light production that can be partially obviated by the simultaneous addition of SOD. In phosphate buffer, the luminescence is higher than in veronal and it is efficiently quenched by all four OH · quenchers and by SOD. In Tris buffer, no light production is observed as long as the Fe²⁺ is not complexed. When Fe²⁺ is complexed by pyrophosphate or phytate, there is a strong chemiluminescence in all three buffers, which is quenched by all four OH · quenchers and by SOD. When Fe²⁺ is complexed by EDTA or DTPA, very little luminescence is observed. The luminol analogue phthalhydrazide, which was suggested by Merényi and Lind as a reliable OH · detector, can replace luminol only in phosphate buffer, and thus turns out to be very specific indeed for free OH ·.     

The oxidation of NADH by tetravalent vanadium

Vanadyl (V_(IV)) salts autoxidize in neutral aqueous solution yielding O₂⁻ plus vanadate (V_(V)) and these, in turn, cause the oxidation of NADH, by a free radical chain reaction. This oxidation of NADH was inhibited by superoxide dismutase, but not by a scavenger of HO.. When H₂O₂ was present V_(IV)) caused rapid oxidation of NADH by a process which was unaffected by superoxide dismutase but was inhibited by a scavenger of HO.. This appeared to be dependent upon reduction of H₂O₂ to OH⁻ plus HO., by V_(IV)), followed by oxidation of NADH by HO.. Since there are reductants, within cells, capable of reducing V_(V)) to V_(IV), these reactions are likely to contribute to the toxicity of vanadate.