Defensive scent of the black stink-roach Platyzosteria novaeseelandiae

The defensive secretion of the New Zealand black stink-roach, Platyzosteria novaeseelandiae was found to consist of E-2-octenal and E-2-hexenal. The taxonomic significance of these results, the scent gland morphology, and the effectiveness of the secretion in deterring predators are also discussed.     

Effects of elevated temperature on seasonal in situ leaf productivity of Thalassia testudinum Banks ex König and Syringodium filiforme Kützing

Net leaf productivities of Thalassia testudinum Banks ex König and Syringodium filiforme Kützing, measured in situ over a 1-year period in a sub-tropical estuary that receives thermal addition from a local power plant, were significantly temperature dependent. Primary production in both species followed seasonal temperature variation, with increase in leaf dry weight as a proportion of total leaf biomass ranging from 0.12% to 2.54% day^?1 for T. testudinum and 0.33% to 3.80% day^?1 for S. filiforme. From September to May, S. filiforme exhibited significantly higher productivity at the thermally-impacted (experimental) station than at the control station. However, from June to August, S. filiforme productivity at the experimental station was significantly lower than at the control station. T. testudinum productivity showed similar trends, but interstation differences were not statistically different. Maximal growth occurred between 23 and 29°C for S. filiforme and 23 and 31°C for T. testudinum. Thus, the thermal addition generally enhanced the seagrass productivity of both species in the autumn, winter, and spring, but reduced that of S. filiforme in the summer, as the optimal temperature range of this species was exceeded. The fact that T. testudinum exhibited a less marked response to the thermal addition and had a greater optimal temperature range than S. filiforme supports its status as the more eurythermal of the 2 species.     

Co(II)-substituted Octopus vulgaris hemocyanin

Co(II)-substituted hemocyanin (Co(II)Hc) of the octopus, Octopus vulgaris, has been prepared by dialysis of apohemocyanin against Co(II·) ion and subsequent Chelex-treatment. The blue 50%-Co(II)Hc (half-apo Co(II)Hc), in which binuclear coppers are replaced in the hemocyanin by a single Co(II), exhibits two absorption maxima at 560 (?_Co=250) and 594 nm (?_Co=320 M^?1 cm^?1) and a shoulder near 610 nm, all of which are attributed to a dd transition of high spin Co(II) (S=3/2) with a tetrahedral geometry. The magnetic circular dichroism (MCD) spectrum in this region also suggests the existence of a tetrahedral Co(II) species in the protein. The visible absorption and MCD spectra of octopus 50%-Co(II)Hc are quite similar to those of squid 50%-Co(II)Hc described in the previous paper (S. Suzuki, J. Kino, M. Kimura, W. Mori and A. Nakahara, Inorg. Chim. Acta, 66, 41 (1982)). The formation of half-apo Co(II)Hc demonstrates that the binuclear copper sites in native octopus hemocyanin may differ from each other in coordination geometry, as in other molluscan hemocyanins, squid and snail hemocyanins. The coordination environment of the active-site Co(II) substituted for Cu in the octopus hemocyanin is the same as that of the corresponding active site of the squid hemocyanin.     

Macrocyclic polyphosphane ligands: cobalt(II) and nickel(II) complexes of 1,10-dipropyl-4RS, 7SR, 13SR, 16RS-tetraphenyl-1,10-diaza-4,7,13,16-tetraphospha-cyclooctadecane and crystal structure of the cobalt tetraphenylborate monohydrate complex

The X-ray crystal structure of the title compound has been carried out. The crystals are triclinic, space group P$\text{1}$, a = 13.252(2), b = 13.943(2), c = 24.316(5) Å, α = 70.660(14), β = 75.219(14), γ = 69.231(13)° for Z = 2. The structure has been refined to an R factor of 0.069 by the least-squares technique. The cobalt atom is five-coordinated by the four phosphorus atoms of the macrocycle and by a water molecule forming a distorted square-pyramidal geometry. The stereochemistry of some cobalt(II) and nickel(II) complexes of the same ligand were investigated, in the solid state and in solution, by electronic spectroscopy.     

Structure of a β-galactan isolated from the nuclei of Physarum polycephalum

A sulfated and phosphorylated β-D-galactan ([α]_D + 8°) was isolated from the nuclei of the acellular slime mould Physarum polycephalum. The polysaccharide was isolated from cesium chloride gradients during the preparation of ribosomal DNA and purified. The purified galactan contained 89% galactose, 2.5% phosphate and 9.6% sulfate groups and had an average degree of polymerisation of 560. Periodate degradation and permethylation studies indicated the presence of mainly (1 → 4)-, but also of (1 → 3)-, and (1 → 6)-linked galactose units with one branch every 13 units. These results suggested that the intranuclear galactan, apart from its higher sulfate content, is similar to the extra-cellular polysaccharide produced by P. polycephalum.     

Micro-video study of discontinuous growth of bacterial flagellar filaments in vitro

In a microscope slide preparation, monomeric flagellins were found to polymerize into flagellar filaments spontaneously, without addition of seeds. Dynamic images of individual growing filaments in a dark-field light microscope were recorded throughout their growth by an ultrasensitive video camera. Each filament had its own unique growth curve. The growth curves consisted of two kinds of discrete phase; namely, the elongation and the rest phase. In the former, a filament elongates at a constant rate, fairly similar among all filaments. In the latter, elongation stops completely. Each filament exists in either of the two phases and alternates between them in a stochastic manner. A mean elongation rate of 89 + 15 nm per minute was obtained at the flagellin concentration of 2 mg/ml, for filaments in the elongation phase.     

In vivo properties of some new cis-platinum complexes containing 7-azaindole ligands

Toxicity data and some preliminary antitumor testing results are reported for the new complexes cis-PtLX₂ (L = 1H-pyrrolo[2,3-b]pyridine, (7-azaindole); X₂ = Cl₂, I₂ oxalate). Although these complexes have the cis-PtN₂X₂ configuration recognised as desirable for effective antitumor behavior, no significant antitumor properties were observed against a number of primary screens; although interesting toxicity differences were observed between the three compounds.     

The use of azidoarylimidoesters in RNA-protein cross-linking studies with Escherichia coli ribosomes

A series of related hetero-bifunctional RNA-protein cross-linking reagents has been prepared, carrying an imidoester or N-hydroxysuccinimide ester function at one end of the molecule, and a phenylazido function at the other. These compounds have been applied to RNA-protein cross-linking studies with ribosomal subunits, and one of them, p-azido-phenylacetic imidoester, has proved to be a particularly useful reagent for this purpose. The reagent first reacts specifically with protein amino groups, and subsequent photolysis of the azide group leads to cross-linking to the RNA in yields of up to 8% of the total protein. The whole reaction takes place under very mild conditions in aqueous solution.The individual proteins concerned in the cross-links have been identified by two-dimensional gel electrophoresis, and the existence of a covalent cross-link was confirmed by the isolation by two different methods of protein-oligonucleotide complexes carrying a ³²P label. Although most of the ribosomal proteins could be cross-linked to their corresponding ribosomal RNA within the individual subunits, RNA-protein cross-links at the ribosomal subunit interface were only detectable in vanishingly small amounts.The advantages of this type of genuine hetero-bifunctional reagent in RNA-protein cross-linking studies are discussed.     

Expression and relevance of dominance in farmed Rusa deer (Cervus rusa timorensis)

A group of 50 hinds and four Rusa stags (Cervus rusa timorensis) were observed over a 2-year period under farming conditions. The aim of the study was to investigate the expression and relevance of dominance. A dominance order was calculated for the hinds. No significant influence of dominance value in relation to calving time, presence or absence of calf, mating time for the following season or the age of the hinds was found. The number of victories in comparison to the total number of interactions between stags was influenced by possession of a full set of antlers for young as well as old stags. However, the antler size or shape did not affect successful participation in the rutting activities of the stags. Hinds did not show a preference for stags based on antler appearance. It is recommended that stags should be velveted so as to minimize differences in antler shape and consequently to reduce dominance interactions between them.     

Isolation,identification, and biological activity of 23,25,26-trihydroxyvitamin D3, an in vitro and in vivo metabolite of vitamin D3

Kidney homogenates from vitamin D₃-supplemented chicks incubated with 25-hydroxyvitamin D₃ [25(OH)D₃] produce significant quantities of a new, unknown vitamin D metabolite. This metabolite was isolated in pure form from such incubation mixtures by using Sephadex LH-20 column chromatography followed by high-pressure liquid chromatography. This metabolite has been identified as 23,25,26-trihydroxyvitamin D₃ [23,25,26(OH)₃D₃] by loss of radioactivity from 25-hydroxy[23,24-³H]vitamin D₃ and 25-hydroxy-[26,27-methyl-³H]vitamin D₃, ultraviolet absorption spectrophotometry, mass spectrometry, and periodate cleavage oxidation followed by mass spectrometry. This same metabolite was also isolated from the serum of rats given large doses of vitamin D₃, and structurally characterized as 23,25,26-trihydroxyvitamin D₃. As yet, the stereochemistry at the C-23 and C-25 positions of the natural product remains unknown. A comparison of responses to a single dose level (500 ng) of 23,25,26(OH)₃D₃ or 25(OH)D₃ over 96 h in vitamin D-deficient rats indicated that the new metabolite had no capability to mediate bone calcium mobilization and that it was only weakly active in stimulating intestinal calcium transport.     

Synthesis of high cis polyacetylene with coordination catalysts consisting of rare earth naphtenate

High cis polyacetylene films with silvery metallic appearance were prepared by coordination catalysts, comprising of naphthenates of all fifteen rare earth elements, and trialkyl aluminum at room temperature. The resultant polyacetylene (PA)was characterized by infrared spectrophotometry, electron spin resonance, X-ray diffraction, scanning and transmission electron micrography, differential scanning calorimetry and electrical resistivity measurements. The enthalpy and apparent activation energy of thermal cis-trans isomerization of 98% cis PA were 1.7–1.8 kcal/mol and 19.0 kcal/mol respectively. Rare earth PA shows higher thermal and antioxidization stability than does PA with other catalysts.     

Biphasic mineral nutrition of the submersed aquatic macrophyte Potamogeton pectinatus L.

The mineral nutrition of a clone of the submersed aquatic macrophyte Potamogeton pectinatus L. was examined in relation to the ability of the roots to mobilize N, P, K, S, Ca, Mg, dissolved inorganic C and micronutrients to the shoots from a constant small volume of sediment in the absence of one or more of these nutrients in the water phase. Survival, biomass production and shoot nutrient concentration values were measured after 35 days of growth under controlled conditions. Flower production and shoot morphology were also noted.The roots of P. pectinatus were capable of mobilizing sufficient P, N, S, K and micronutrients from the sediment to the shoots to meet normal growth requirements. In the absence of K from the water phase, Na replaced it, but the vigor of the plants suffered somewhat by the substitution. The roots were not capable of mobilizing sufficient Mg, Ca, or dissolved inorganic C from the sediment to the shoots to meet normal growth requirements. Survival and normal growth occurred with a minimum of 2 ppm Ca, 10 ppm Mg, and 0.5 meq HCO₃^? in the water phase. Water-phase Ca was necessary to prevent the toxicity of other cations such as Mg when present in the water phase.A seasonal periodicity in biomass production occurred under standardized environmental conditions, suggesting an internal regulation independent of obvious external signals.     

Precocene II-induced alate production in isolated and crowded alate and apterous virginoparae of the aphid, Macrosiphum euphorbiae

Precocene II was applied at doses ranging from 0.05 to 0.70 μg per individual to newly moulted adult alate and apterous virginoparae of Macrosiphum euphorbiae kept isolated or in groups of 10 per plant, under an 18L:6D photoperiodic regime. While isolated controls of both morphs produced exclusively apterous progeny, alatae virginoparae were produced in generally dose-dependent proportions by precocene-treated individuals. Grouped controls of both morphs produced alatiform progeny as expected, but in precocene—treated groups, the proportions of alate progeny generally increased as a function of dose. The overall proportions of alate offspring produced, and numbers of days after treatment when morph production was affected, were generally greater for alatae than for apterae, indicating a greater sensitivity to precocene in alatae. However during the first few days after treatment, the alatizing effect of precocene was stronger for apterae, suggesting that the first embryos produced by alatae were irreversibly determined as apterae.In an experiment where isolated alatae and apterae received 0.5 μg of precocene II at different ages ranging from 1 to 13 days after the adult moult, the alatizing effect of the compound, measured by the persistence of alate production, varied with age and morph. While in alatae, the persistence decreased more or less regularly with age, in apterae it initially increased to a maximum in the middle of reproductive life, and subsequently decreased. The results provide support for the hypothesis that juvenile hormone is involved in regulating alary dimorphism in M. euphorbiae.     

Fate of Gallium in vivo and its significance in tumour diagnosis and therapy respectively with gallium-67 and cold gallium

Early tumour diagnosis with high quality images is obtained by injecting gallium-67 made free before intravenous administration. No healthy organ uptake of the radionuclide administered in this form takes place. Since free cationic gallium is readily hydrolyzed in aqueous solution, the solution of gallium-67 should be made just before injection from commercial solutions. Both strongly-bound and hydrolyzed gallium-67 concentrate in healthy organs, like liver.Free cold gallium solutions have been successfully used in the treatment of experimental mammary tumour (TGS) in mice.     

Inhibition of wheat germ RNA polymerase II by 2,6-dibromobenzoquinone and related compounds from Aplysina fistularis

Among the antifungal compounds from Aplysina fistularis, 2,6-dibromobenzoquinone (DBQ) was the most potent inhibitor of wheat germ RNA polymerase II (Ribonucleosidetriphosphate: RNA nucleotidyltransferase, EC 2.7.7.6). DBQ appeared to inhibit the enzyme activity by binding to the enzyme but not to the DNA template. DNA offered slight protection to the enzyme against the inhibitor. Chain initiation was more sensitive to the inhibitor than chain elongation. No enzymatic activity was detected in fractions from a Sephadex G-25 column that contained polymerase which had been preincubated with DBQ, and if the DBQ was labeled with C¹⁴, the radioactivity co-chromatographed with the polymerase.     

Amphiphile-mediated activation of soluble adenylate cyclase of Bordetella pertussis

The adenylate cyclase activity of Bordetella pertussis culture supernatants is activated 3- to 10-fold by various amphiphiles including many classes of phospholipids and nonionic detergents. Gangliosides are inhibitory. The stimulation affects the V_max and not the K_m. Neither the nature of the polar head group, the length of the fatty acid chains, nor the hydrophile-lipophile balance (in the Triton X series) are major determinants for activation. Short-chain lecithins activate as monomers, whereas long-chain lecithins activate only above the critical micelle concentrations, suggesting high-affinity hydrophobic binding sites. Judged by EGTA inhibition, the amphiphile-mediated activation requires Ca²⁺ in the absence of calmodulin. In addition, amphiphiles sensitize the adenylate cyclase to Ca²⁺/calmodulin and are also synergistic with calmodulin for maximal stimulation.     

Ultrastructural studies of the effects produced by some amino acid metal systems on escherichia coli B

Escherichia coli cells were grown in the presence of L-serine and gallium(III) nitrate a different molar ratios. Under these conditions ultrastructural changes were observed in the cells when examined under the electron microscope. Although some changes were seen inside the cell the major modifications were observed at the cell surface. These changes appeared to involve both the cell and the peptidoglycan layer. Autoradiography at the electron microscope level undertaken with similar mixtures and containing L-(3 - 3H) serine showed silver grains at or near the cell surface. In some cases, surface modifications were so pronounced that they resulted in the E. coli appearing as sheets of cells.No cell surface changes were detected when mixtures of L-serine and potassium tetrachloropalladate(II) were used as modifying agents. With the palladium(II) mixtures all changes observed were intracellular. These modifications included the appearance of membrane-bound vehicles, clumping of the cytoplasm and changes in the nucleoplasm. Autoradiography carried out in the presence of L-(3 - 3H) serine showed a significant proportion of silver grains over the nuclear region. A pure palladium(II) complex of L-serine was examined as a modifying agent in the concentration range 1–9 μ/cm³ resulting in very pronounced modification of the cells when exposed to higher concentrations.