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The -CH(2)- group of the 2-nitrobenzyl pendant arm of the scorpionate complex I deprotonates in basic aqueous solution (pK(a) = 10.6), due to the coordination of the nitronate group to the nickel(II) center. Metal coordination enhances 2-nitrobenzene acidity by 10 orders of magnitude. [reaction: see text]
A novel real-time quantitative method for measuring telomerase activity is described in which the duplex scorpion primer is used to provide an intramolecular probing mechanism for specific detection of telomerase activity. Using this method, linearity from 10 to 10(4) cells expressing telomerase activity could be obtained (R2 = 0.994). The requirement of post-PCR steps is thus obviated.
Gold derivatives [Au(Tpx)(PR3)](Tpx = Tp, hydrotris(pyrazol-1-yl)borate or Tp*, hydrotris(3,5-dimethylpyrazol-1-yl)borate; R = Ph or tBu) and [Au(pzTp)(PR3)x](pzTp = tetrakis(pyrazol-1-yl)borate, x = 1 or 2, R = Ph or tBu) have been synthesised and characterized both in solution (1H- and 31P[1H]-NMR) and in the solid state (IR, single crystal X-ray structure analysis, 31P CPMAS). 31P [1H] NMR solution data suggest greater stability of the tetrakis(pyrazolyl)borate relative to those of tris(pyrazolyl)borate. All compounds are fluxional at room temperature. In order to compare [Au(Tp*)(PPh3)] with analogous coinage metal adducts we have synthesized and structurally characterized [Cu(Tp*)(PPh3)] x PPh3 and [Ag(Tp*)(PPh3)] x 2MeCN. In [Au(Tp*)(PPh3)] the gold atom adopts a distorted tetrahedral geometry with 2.181(5) and 2.37(2) angstroms (cf. 2.166(6), 2.098(1) in [Cu(Tp*)PPh3], 2.156(2), 2.075(7) in [Cu(Tp*)(PPh3)] x PPh3; and in [Ag(Tp*)PPh3] x MeCN 2.347(12), 2.35(5) angstroms). There are three independent [Au(Tp*)(PPh3)] molecules in the asymmetric unit of the structure with their PAu...B axes lying on the cell diagonal of a cubic P213 cell, two with the same chirality aligned opposed in direction to the third which is of opposite chirality. A number of Cu, Ag and Au complexes containing scorpionate ligands have also been investigated by 31P cross-polarization magic-angle-spinning (CPMAS) NMR spectroscopy.
The structure of toxin II from the scorpion Androctonus australis Hector has been determined ab initio by direct methods using SnB at 0.96 A resolution. For the purpose of this structure redetermination, undertaken as a test of the minimal function and the SnB program, the identity and sequence of the protein was withheld from part of the research team. A single solution obtained from 1 619 random atom trials was clearly revealed by the bimodal distribution of the final value of the minimal function associated with each individual trial. Five peptide fragments were identified from a conservative analysis of the initial E-map, and following several refinement cycles with X-PLOR, a model was built of the complete structure. At the end of the X-PLOR refinement, the sequence was compared with the published sequence and 57 of the 64 residues had been correctly identified. Two errors in sequence resulted from side chains with similar size while the rest of the errors were a result of severe disorder or high thermal motion in the side chains. Given the amino-acid sequence, it is estimated that the initial E-map could have produced a model containing 99% of all main-chain and 81% of side-chain atoms. The structure refinement was completed with PROFFT, including the contributions of protein H atoms, and converged at a residual of 0.158 for 30 609 data with F >or= 2sigma(F) in the resolution range 8.0-0.964 A. The final model consisted of 518 non-H protein atoms (36 disordered), 407 H atoms, and 129 water molecules (43 with occupancies less than unity). This total of 647 non-H atoms represents the largest light-atom structure solved to date.
The ultrastructure of a new microsporidian species Microgemma vivaresi n. sp. causing liver cell xenoma formation in sea scorpions, Taurulus bubalis, is described. Stages of merogony, sporogony, and sporogenesis are mixed in the central cytoplasm of developing xenomas. All stages have unpaired nuclei. Uninucleate and multinucleate meronts lie within vacuoles formed from host endoplasmic reticulum and divide by binary or multiple fission. Sporonts, no longer in vacuoles, deposit plaques of surface coat on the plasma membrane that cause the surface to pucker. Division occurs at the puckered stage into sporoblast mother cells, on which plaques join up to complete the surface coat. A final binary fission gives rise to sporoblasts. A dense globule, thought to be involved in polar tube synthesis, is gradually dispersed during spore maturation. Spores are broadly ovoid, have a large posterior vacuole, and measure 3.6 microm x 2.1 microm (fresh). The polar tube has a short wide anterior section that constricts abruptly, then runs posteriad to coil about eight times around the posterior vacuole with granular contents. The polaroplast has up to 40 membranes arranged in pairs mostly attached to the wide region of the polar tube and directed posteriorly around a cytoplasm of a coarsely granular appearance. The species is placed alongside the type species Microgemma hepaticusRalphs and Matthews 1986 within the family Tetramicridae, which is transferred from the class Dihaplophasea to the class Haplophasea, as there is no evidence for the occurrence of a diplokaryotic phase.
Free and bound forms of hexokinase, pyruvate kinase, and lactate dehydrogenase were prepared from the brain of the sea scorpion (Scorpaena porcus) in a low ionic strength medium. Properties of the free and bound forms were compared to determine whether binding to particulate matter could influence enzyme function or stability in vivo. Changes in pH differently affected the activity of the free and bound forms of all three enzymes. Furthermore, bound forms of hexokinase and pyruvate kinase were more stable than the free enzymes to heating at 45 degrees C. Bound hexokinase showed higher affinity for substrates (ATP, glucose) than the free form and bound lactate dehydrogenase had greater affinity for pyruvate and NADH. Although the affinities of the two forms of pyruvate kinase for substrates were similar, Hill coefficients for phosphoenolpyruvate as well as inhibition by ATP differed between the two enzyme forms. Free and bound lactate dehydrogenase also showed differences in Hill coefficients and bound lactate dehydrogenase was less sensitive to substrate inhibition by high pyruvate concentrations. The possible physiological role of the binding of these glycolytic enzymes to subcellular structures is discussed.
Xenomas caused by Microgemma vivaresi Canning, Feist, Longshaw, Okamura, Anderson, Tsuey Tse et Curry, 2005 were found in liver and skeletal muscle of sea scorpions, Taurulus bubalis (Euphrasen). All muscle xenomas examined were in an advanced stage of destruction. In developing xenomas found in liver, parasites were restricted to the centre of the cell, separated from a parasite-free zone by a nuclear network formed by branching of the host cell nucleus. Although xenomas were able to reach a size of several hundred microns, the surface remained a simple plasma membrane. Host reactions took the form of penetration by phagocytes and isolation by fibroblasts. Once the xenoma had been attacked, the nuclear profiles became pycnotic and the barrier between parasitized and parasite-free zones was lost. Parasite antigens cannot be exposed at the surface of intact xenomas, as the host does not recognise the enlarging cell as foreign. Breaches in the plasma membrane of the xenoma and leakage of parasite antigens are thought to be the stimuli for phagocyte entry into the cell, its isolation by fibroblasts and eventual granuloma formation.
The absence of nucleoli and rRNA synthesis in oocyte nuclei of the scorpion fly, Panorpa communis, was demonstrated using hybridization in situ. The immunocytochemical characteristics of a single large nuclear body of P. communis oocytes has been done which enabled us to recognize this structure as a Cajal body (CB). A marker of CBs coilin was detected in CBs of P. communis oocytes in addition to Sm-epitope of small nuclear RNPs (snRNPs), trimethylguanosine cap of snRNAs, and non-snRNP splicing factor, SC35. Besides, inactive hyperphosphorylated and nonphosphorylated forms of RNA polymerase II were also found in CBs. We put forward a suposition on possible roles of CBs in P. communis oocytes. On the one hand, CBs take part in the storage of RNA transcription and processing components to be used later during embryogenesis. On the other hand, they provide the primary assembly and redistribution of pre-mRNA transcription and processing components of the oocyte itself.
To purify and characterize peptides from the venom of Chinese scorpion Buthus martensi Karsch, the purification was carried out by gel-filtration, ion exchange and reversed phase HPLC techniques. The purified peptide was reduced by dithioerythritol (DTT), S-alkylated with iodoacetic acid, and subjected to enzymatic cleavages (TPCK-trypsin). The purified fragments from enzymatic cleavage of the peptide were separated by C(18)HPLC, then submitted to the ESI-MS, and Edman degradation for amino acid sequence determination. The mixture was also subjected to tandem mass (MS-MS) analysis. As a result, a novel peptide, named BmK4112, was obtained, with the primary structure being TPYPV NCKTD RDCVM CGLGI SCKNG YCTGQ C, and having three disulfide bonds.
Low doses of pentagastrin (50 mug/kg b. w.) have no physiological effect on motor activity of the stomach in the skate Dasyatis pastinaca. Average doses (100-200 mug/kg) stimulate the activity, whereas high ones (300 mug/kg) inhibit the frequency of stomach contractions, slightly increasing their amplitude. Ornithine tetragastrin in a dose 2000 mug/kg does not affect motor activity of the stomach in skates. In the scorpion-fish Scorpaena porcus, ornithine tetragastrin (1000 and 2000 mug/kg) inhibits motor activity of the stomach.
A comparative cross platform evaluation of real-time polymerase chain reaction detection of DNA sequences present in Roundup Ready soya was undertaken using the ABI 7700 and Roche Lightcycler detection systems in combination with 3 different detection chemistries: TaqMan, Scorpion primers, and SYBR Green I fluorescent dye. Various copy numbers of a plasmid containing the soya lectin sequence were used to determine the sensitivity and reproducibility of the different technology combinations and to examine both inter and intra machine variability. To examine the relative accuracy of each technology, the genetically modified soya content of baked products containing known amounts of Roundup Ready soya was determined by detection of lectin and the EPSPS transgene. It was determined that the combination of TaqMan detection chemistry and the ABI 7700 platform represented the best method for quantitative detection of genetically modified organisms in terms of both precision and accuracy.
Glutathione-S-transferase activity in the blood of scorpion fish inhabiting coastal areas of Sevastopol depending on sex, age and season were studied. The decrease of glutathione-S-transferase activities has been observed with fish ageing.
Over 950 students attending Volant Scorpion training during March-August 1988 reported the number and impact of tick bites and the personal protective measures used during their training at Little Rock Air Force Base. In some classes, as many as 50% of the students reported 10 or more tick bites. Approximately one third of all students said that ticks had a significant or very significant impact on duty performance. The use of a repellent applied to clothing had no significant effect on the number of tick bites received.
Insulin from the scorpion-fish and porcine insulin have been compared with respect to their capacity to interact with the specific receptors in plasma membrane of skeletal muscle fibers of rats. Both insulins inhibited membrane binding of insulin-125J; the dose of porcine insulin which inhibited binding by 50% was equal to 3.7 nM, that of fish insulin -- to 100 nM. These figures indicated lower affinity of fish insulin to mammalian receptors (4% of the porcine affinity), being in accordance with lower biological activity of fish insulin in diaphragmal test. Other peculiarity of fish insulin was revealed in studies on dissociation of insulin-125J, which was previously bound to isolated diaphragm muscle of the rat. In contrast to mammalian insulin, it was not capable of increasing the dissociation when being added to a solution in doses from 7.10(-11) to 7.10(-9) M. This fact is analysed in term of the "site--site" interactions concept.
In an effort to develop a more effective measure for use in emergency control of the dengue vector Aedes aegypti. applications of a combination of a larvicide (Bacillus thuringiensis israelensis [B.t.i.]) and an adulticide (permethrin) were made using a truck-mounted forced-air generator (Scorpion 20) and evaluated in the Dominican Republic. This method has the potential to simultaneously control adults and larvae. In bioassay cages placed in household water containers at the time of application, larval mortalities were 95.1 and 100% for 2 application rates of permethrin mixed with B.t.i. Adult mortalities were not as impressive, probably because of resistance to permethrin. Higher adult mortality in caged specimens (78.5%) and a substantial reduction in the natural population (68.4%) of Ae. aegypti were obtained following a 2.1-g AI/ha application of deltamethrin alone.
Preparation of the scorpion-like dynamic nitinol osteo-connector (NT-SDOC) and its clinical application in 57 cases were reported. The apparatus was designed with two longitudinal pressure hooks and two to eight semicircular fixation hooks, which could exert an axial continuing stress of 24-56kg on the fracture ends until bone union. Of the 57 cases 31 were fracture and 26 were nonunion, as no plaster cast was applied postoperatively, all patients could exercise their injured arms early. Follow-up was 4 to 32 months with an average of 13.7 months. The osteo-plate substitution was shown at the fracture site at an average of 2.2 months in 31 cases, and at the nonunion site with an average of 3.64 months in 26 cases. No postoperative infection, nonunion and other complications were observed NT-S DOC was removed in 46 cases at about 6 months postoperatively. No refracture occurred at the osteo-plate substitution site.
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