Functional Model of Compound II of Cytochrome P450: Spectroscopic Characterization and Reactivity Studies of a FeIV-OH Complex

Herein, we show that the reaction of a mononuclear FeIII(OH) complex (1) with N-tosyliminobenzyliodinane (PhINTs) resulted in the formation of a FeIV(OH) species (3). The obtained complex 3 was characterized by an array of spectroscopic techniques and represented a rare example of a synthetic FeIV(OH) complex. The reaction of 1 with the one-electron oxidizing agent was reported to form a ligand-oxidized FeIII(OH) complex (2). 3 revealed a one-electron reduction potential of -0.22 V vs Fc+/Fc at -15 °C, which was 150 mV anodically shifted than 2 (Ered = -0.37 V vs Fc+/Fc at -15 °C), inferring 3 to be more oxidizing than 2. 3 reacted spontaneously with (4-OMe-C6H4)3C• to form (4-OMe-C6H4)3C(OH) through rebound of the OH group and displayed significantly faster reactivity than 2. Further, activation of the hydrocarbon C-H and the phenolic O-H bond by 2 and 3 was compared and showed that 3 is a stronger oxidant than 2. A detailed kinetic study established the occurrence of a concerted proton-electron transfer/hydrogen atom transfer reaction of 3. Studying one-electron reduction of 2 and 3 using decamethylferrocene (Fc*) revealed a higher ket of 3 than 2. The study established that the primary coordination sphere around Fe and the redox state of the metal center is very crucial in controlling the reactivity of high-valent Fe-OH complexes. Further, a FeIII(OMe) complex (4) was synthesized and thoroughly characterized, including X-ray structure determination. The reaction of 4 with PhINTs resulted in the formation of a FeIV(OMe) species (5), revealing the presence of two FeIV species with isomer shifts of -0.11 mm/s and = 0.17 mm/s in the Mössbauer spectrum and showed FeIV/FeIII potential at -0.36 V vs Fc+/Fc couple in acetonitrile at -15 °C. The reactivity studies of 5 were investigated and compared with the FeIV(OH) complex (3).

Prognostic factors for deterioration of quality of life one year after admission to ICU for severe SARS-COV2 infection

PURPOSE

Patients with COVID-19 present long-term symptoms collectively known as "post-COVID syndrome". Long-term manifestations are more frequent in patients requiring admission to Intensive Care Units (ICU), but the risk factors for their development are still unknown. This study explores the quality of life of patients with severe COVID-19 one year after their discharge from ICU.

METHODS

Prospective observational study including 106 patients admitted to the ICU of a tertiary care hospital between March and August 2020. We analysed quality of life using the EuroQol-5D index (EQ-5D). We evaluated as possible risk factors associated with a worse value of the EQ-5D index the medical record, the clinical situation at hospital admission, the clinical situation at ICU admission and evolution in the ICU. As a secondary objective, we explored the presence of other frequent symptoms.

RESULTS

Most patients (55.4%) reported that their quality of life worsened one year after admission. The mean perceived health status, on the EQ-VAS scale (0-100), was 70.4, with a median of 70 (RI 60-90). The median EQ-5D index was 0.91 (RI 0.76-1). The factors independently related to lower quality of life were female sex and duration of mechanical ventilation. Almost all (91%) of the patients had sequelae one year after discharge from the ICU. The most frequent manifestations were neuropsychiatric (71%).

CONCLUSIONS

Critically ill COVID-19 patients worsen their quality of life more than one year after discharge. Female sex and duration of mechanical ventilation predict a lower quality of life assessed by the EQ-5D index.

Surface-Promoted Evolution of Ru-bda Coordination Oligomers Boosts the Efficiency of Water Oxidation Molecular Anodes

A new Ru oligomer of formula {[Ru^II(bda-κ-N²O²)(4,4'-bpy)]₁₀(4,4'-bpy)}, 10 (bda is [2,2'-bipyridine]-6,6'-dicarboxylate and 4,4'-bpy is 4,4'-bipyridine), was synthesized and thoroughly characterized with spectroscopic, X-ray, and electrochemical techniques. This oligomer exhibits strong affinity for graphitic materials through CH-π interactions and thus easily anchors on multiwalled carbon nanotubes (CNT), generating the molecular hybrid material 10@CNT. The latter acts as a water oxidation catalyst and converts to a new species, 10'(H₂O)₂@CNT, during the electrochemical oxygen evolution process involving solvation and ligand reorganization facilitated by the interactions of molecular Ru catalyst and the surface. This heterogeneous system has been shown to be a powerful and robust molecular hybrid anode for electrocatalytic water oxidation into molecular oxygen, achieving current densities in the range of 200 mA/cm² at pH 7 under an applied potential of 1.45 V vs NHE. The remarkable long-term stability of this hybrid material during turnover is rationalized based on the supramolecular interaction of the catalyst with the graphitic surface.

Structure and excited-state dynamics of dimeric copper(i) photosensitizers investigated by time-resolved X-ray and optical transient absorption spectroscopy

Time-resolved X-ray (tr-XAS) and optical transient absorption (OTA) spectroscopy in the picosecond time scale coupled with Density Functional theory (DFT) and X-ray absorption near-edge structure (XANES) calculations are applied to study three homoleptic Cu(i) dimeric chromophores with ethyl and longer propyl spacers, denoted as [Cu₂(mphenet)₂]Cl₂ (C1), [Cu₂(mphenet)₂](ClO₄)₂ (C2) and [Cu₂(mphenpr)₂](ClO₄)₂ (C3) (where mphenet = 1,2-bis(9-methyl-1,10-phenanthrolin-2-yl)ethane and mphenpr = 1,3-bis(9-methyl-1,10-phenanthrolin-2-yl)propane). Tr-XAS analysis after light illumination at ∼ 100 ps illustrate the formation of a flattened triplet excited state in all 3 complexes. Optical transient absorption (OTA) analysis for C1 monitored in water and C2 and C3 measured in acetonitrile reveals distinct excited-state lifetimes of 169 ps, 670 ps and 1600 ps respectively. These differences are associated to changes in the solvent (comparing C1 and C2) and the flexibility of the ligand to adapt after Cu flattening upon excitation (C2 and C3). Our results are important for the improved structural dynamics of these types of Cu-based dimeric compounds, and can guide the integration of these chromophores into more complex solar energy conversion schemes.

Characterization and reactivity study of non-heme high-valent iron-hydroxo complexes

A terminal Fe^IIIOH complex, [Fe^III(L)(OH)]²⁻ (1), has been synthesized and structurally characterized (H₄L = 1,2-bis(2-hydroxy-2-methylpropanamido)benzene). The oxidation reaction of 1 with one equiv. of tris(4-bromophenyl)ammoniumyl hexachloroantimonate (TBAH) or ceric ammonium nitrate (CAN) in acetonitrile at −45 °C results in the formation of a Fe^IIIOH ligand radical complex, [Fe^III(L˙)(OH)]⁻ (2), which is hereby characterized by UV-visible, ¹H nuclear magnetic resonance, electron paramagnetic resonance, and X-ray absorption spectroscopy techniques. The reaction of 2 with a triphenylcarbon radical further gives triphenylmethanol and mimics the so-called oxygen rebound step of Cpd II of cytochrome P450. Furthermore, the reaction of 2 was explored with different 4-substituted-2,6-di-tert-butylphenols. Based on kinetic analysis, a hydrogen atom transfer (HAT) mechanism has been established. A pK_a value of 19.3 and a BDFE value of 78.2 kcal/mol have been estimated for complex 2.

One-electron oxidation of an Fe^III–OH complex (1) results in the formation of a Fe^III–OH ligand radical complex (2). Its reaction with (C₆H₅)₃C˙ results in the formation of (C₆H₅)₃COH, which is a functional mimic of compound II of cytochrome P450.

Towards a carrier SDN: an example for elastic inter-datacenter connectivity

We propose a network-driven transfer mode for cloud operations in a step towards a carrier SDN. Inter-datacenter connectivity is requested in terms of volume of data and completion time. The SDN controller translates and forwards requests to an ABNO controller in charge of a flexgrid network.

First Report of Grapevine leafroll-associated virus 5 in Spain

Grapevine leafroll-associated viruses (GLRaVs) cause significant reductions in yield and quality in the wine industry worldwide. At least nine different GLRaVs have been found in different regions of the world. In the process of virus indexing of candidate grapevine clones for certification, which includes grafting of scions onto rootstocks, we observed strong leafroll symptoms 1 year after grafting with one vine of cv. Estaladina in Castilla y León, Spain and one vine of cv. Tempranillo in La Rioja, Spain, collected in 2008 and 2007, respectively. Both vines tested positive by real-time reverse transcription (RT)-PCR with TaqMan probes specific for Grapevine leafroll-associated virus 5 and double-antibody sandwich (DAS)-ELISA with a mix of monoclonal antibodies that recognizes GLRaV-4, 5, 6, 7, and 9 (Bioreba, Reinach, Switzerland). RNA extracts of both GLRaV-5 positive vines were analyzed by conventional RT-PCR with a pair of consensus degenerated primers derived from GLRaV-5 hsp70 sequences available in GenBank: LR5HYF (5'-TGGGATGAAYAARTTCAATGC-3') and LR5HYR (5'-TGAAATTCCTCATRTARGAGC-3') that amplified a 250-bp fragment. Amplicons were cloned and the comparison of the amino acid sequences (Estaladina isolate, Est110: Accession No. HM208622; Tempranillo isolate, Tem020: Accession No. HM208618) showed in the case of the Est110 isolate, 100 and 82.6% identity, respectively, with the homologous genes of one GLRaV-5 isolate from the United States (AF233934 [3]) and Argentina (EU815935 [2]). For isolate Tem020, the hsp70 gene showed 97.1 and 81.2% amino acid identity with the homologous hsp70 genes of the United States and Argentina isolates. The coat protein (cp) genes of both isolates were also amplified and cloned using the specific GLRaV-5 primers, LR53413 (5'-CGTGATACAAGGTAGGACAACCGT-3') and LR53843 (5'-CTTGCACTATCGCTGCCGTGAAT-3'), designed according to the sequence of AF233934. Fragments were of the expected size (430 bp) and the nucleotide sequences were obtained (Est110: Accession No. HM363522; Tem020: Accession No. HM363523) and used for pairwise nucleotide comparisons. The Est110 isolate showed 96.7 and 97.5% amino acid identity with the isolates from the United States and Argentina, respectively, while the Tem020 isolate showed 94.8 and 95.6% identity, respectively. Amino acid identity of Est110 and Tem020 cp genes was 100% when compared with the homologous genes of isolates AF233934 and EU815935. To our knowledge this is the first report of GRLaV-5 in Spain. Since 2008, we have detected eight additional vines positive for this virus in 200 clones analyzed for certification, suggesting that the incidence of GLRaV-5 in Spain could be widespread. This research indicates that virus indexing for GLRaV should be included in certification schemes for grapevine candidate clones (1) in Spain. References: (1) Anonymous. OEPP/EPPO Bull. 38:422, 2008. (2) S. Gomez Talquenca et al. Virus Genes 38:184, 2009. (3) F. Osman et al. J. Virol. Methods 141:22, 2007.

Transferability, amplification quality, and genome specificity of microsatellites in Brassica carinata and related species

No information is available on the transferability and amplification quality of microsatellite (SSR) markers of the public domain in Brassica carinata A. Braun. The objective of the presented research was to study the amplification of a set of 73 SSRs from B. nigra (L.) Koch and B. napus L. in B. carinata, and to compare the results with those obtained in the amplification of the same markers in other Brassica species of the U triangle. This set of SSRs from B. nigra (B genome) and B. napus (AC genome) allows the identification of the 3 basic genomes of the Brassica species tested. 94.3% of the SSR markers from B. nigra and 97.4% of those from B. napus amplified SSR-specific products in B. carinata. Very high-quality amplification with a strong signal and easy scoring in B. carinata was recorded for 52.8% of the specific loci from B. nigra SSRs and 59.3% of the specific loci from B. napus SSRs, compared to 66.7% in B. nigra and 62.8% in B. napus. Genome specificity and amplification quality of B. nigra and B. napus SSR markers in the 6 species under study is reported. High-quality transferable SSR markers provide an efficient and cost-effective platform to advance in molecular research in B. carinata.

Putrescine modulation of acute activation of the beta-adrenergic system in the left atrium of rat

Endogenous polyamines mediate acute metabolic effects and cardiac hypertrophy associated to beta-adrenoceptor stimulation. The aim of this study is to characterize the role of polyamines on beta-adrenoceptor system mediated responses. To this end, the functional interaction of polyamine modifying drugs on isoproterenol-elicited cardiotonic effect, in isolated left atria of male Wistar rats, and their effects on [(3)H]dihydroalprenolol (DHA) binding on beta-adrenoceptors and on adenylyl cyclase activity of membrane heart were studied. Polyamines interact with beta-adrenoceptors in rat heart, as shown by the displacement of [(3)H]DHA binding. Furthermore, putrescine (but not spermidine or spermine) increased adenylyl cyclase activity, elicited a positive inotropism and increased intracellular cAMP. The putrescine effect on adenylyl cyclase was not antagonized by the beta-adrenoceptors blockers, alprenolol and ICI-118,551, and facilitated the isoproterenol effect. Neither alprenolol, atenolol nor ICI-118,551 antagonized putrescine-elicited positive inotropism. However, the effect was abolished in preparations with desensitized beta-adrenoceptors. alpha-Difluoromethylornithine, an inhibitor of ornithine decarboxylase, antagonized the effect of isoproterenol on inotropism and cAMP increase. In addition, putrescine might elicit effects by mechanisms independent of beta-adrenoceptor system, since in left atria with functional desensitized receptors an interaction with ouabain-elicited cardiotonic effect was observed. These results suggest that putrescine may act as a low affinity agonist on beta-adrenoceptors and modulate acute responses mediated by beta-adrenoceptors. These findings may be of importance in the physiology and in diseases involving cardiac beta-adrenoceptors.

Molecular analysis of the high stearic acid content in sunflower mutant CAS-14

Increasing the stearic acid content to improve sunflower (Helianthus annuus L.) oil quality is a desirable breeding objective for food-processing applications. CAS-14 is a sunflower mutant line with a high stearic acid content in its seed oil (>35% vs. <6% in currently grown sunflower hybrids), which is controlled by the Es3 gene. However, the expression of the high stearic acid character in CAS-14 is strongly influenced by temperature during seed maturation and it is not uniform along the seed. The objectives of this study were (1) to identify PCR-based molecular markers linked to the Es3 gene from CAS-14, (2) to map this gene on the sunflower genetic map, and (3) to characterize the interaction between CAS-14 and CAS-3, a sunflower high stearic acid (about 26%) mutant line with the Es1 and Es2 genes determining this trait. Two F2 mapping populations were developed from crosses between CAS-14 and P21, a nuclear male sterile line with the Ms11 gene controlling this character, and between CAS-14 and CAS-3. One hundred and thirty-three individuals from P21xCAS-14, and 164 individuals from CAS-3xCAS-14 were phenotyped in F2 and F3 seed generations for fatty acid composition using gas-liquid chromatography, and they were then genotyped with microsatellite [simple sequence repeat (SSR)] and insertion-deletion (INDEL) markers. Bulk segregant analysis in the P21xCAS-14 population identified two markers on LG 8 putatively linked to Es3. A large linkage group was identified using additional markers mapping to LG 8. Es3 mapped to the distal half of LG 8 and was flanked by the SSR markers ORS243 and ORS1161 at genetic distances of 0.5, and 3.9 cM, respectively. The Ms11 gene was also mapped to LG 8 and genetic distance between this gene and Es3 was found to be 7.4 cM. In the CAS-3xCAS-14 population, two QTLs were identified on LG 1 and LG 8, which underlie the Es1 gene from CAS-3 and the Es3 gene from CAS-14, respectively. A significant epistatic interaction between these two QTLs was found. Results from this study provided a basis for determining CAS-14 efficient breeding strategies.

Absence of a coding region for the helper component-proteinase in the genome of cucumber vein yellowing virus, a whitefly-transmitted member of the Potyviridae

The complete nucleotide sequence of isolates of Cucumber vein yellowing virus (CVYV) has been determined. The viral genome comprises 9734 nucleotides, excluding a 3'-terminal poly(A) sequence. The genome of CVYV has a 5'-non coding and a 3' non coding region of respectively 67 and 240 nucleotides. The RNA of CVYV encodes a single polyprotein of 3148 amino acid residues and has a deduced genome organization and motifs typical for a member of the family Potyviridae. However, CVYV is atypical because it lacks a coding sequence region for the putative helper-component as well as conserved helper-component-proteinase motifs which may account for its vector relations. All the present coding regions were compared to those from several members of the Potyviridae family. CVYV is most closely related to Sweetpotato mild mottle virus confirming its assignation to the genus Ipomovirus, despite similarities with tritimoviruses.

Excitation of vortices using linear and nonlinear magnetostatic waves

It is shown that stationary vortex structures can be excited in a ferrite film, in the important centimeter and millimeter wavelength ranges. It is shown that both linear and nonlinear structures can be excited using a three-beam interaction created with circular antennas. These give rise to a special phase distribution created by linear and nonlinear mixing. An interesting set of three clockwise rotating vortices joined by one counter-rotating one presents itself in the linear regime: a scenario that is only qualitatively changed by the onset of nonlinearity. It is pointed out that control of the vortex structure, through parametric coupling, based upon a microwave resonator, is possible and that there are many interesting possibilities for applications.

Quantitative trait loci for broomrape (Orobanche cumana Wallr.) resistance in sunflower

Broomrape (Orobanche cumana Wallr.) is a root parasite of sunflower that is regarded as one of the most important constraints of sunflower production in the Mediterranean region. Breeding for resistance is the most effective method of control. P-96 is a sunflower line which shows dominant resistance to broomrape race E and recessive resistance to the very new race F. The objective of this study was to map and characterize quantitative trait loci (QTL) for resistance to race E and to race F of broomrape in P-96. A population from a cross between P-96 and the susceptible line P-21 was phenotyped for broomrape resistance in four experiments, two for race E and two for race F, by measuring different resistance parameters (resistance or susceptibility, number of broomrape per plant, and proportion of resistant plants per F(3) family). This population was also genotyped with microsatellite and RFLP markers. A linkage map comprising 103 marker loci distributed on 17 linkage groups was developed, and composite interval mapping analyses were performed. In total, five QTL ( or1.1, or3.1, or7.1 or13.1 and or13.2) for resistance to race E and six QTL ( or1.1, or4.1, or5.1, or13.1, or13.2 and or16.1) for resistance to race F of broomrape were detected on 7 of the 17 linkage groups. Phenotypic variance for race E resistance was mainly explained by the major QTL or3.1 associated to the resistance or susceptibility character ( R(2)=59%), while race F resistance was explained by QTL with a small to moderate effect ( R(2) from 15.0% to 38.7%), mainly associated with the number of broomrape per plant. Or3.1 was race E-specific, while or1.1, or13.1 and or13.2 of were non-race specific. Or13.1, and or13.2 were stable across the four experiments. Or3.1, and or7.1 were stable over the two race E experiments and or1.1 and or5.1 over the two race F experiments. The results from this study suggest that resistance to broomrape in sunflower is controlled by a combination of qualitative, race-specific resistance affecting the presence or absence of broomrape and a quantitative non-race specific resistance affecting their number.

Interaction of Androgens with Cardiotonic Drugs in Isolated Left Atrium of Rat

Pharmacological concentrations of androgens are known to elicit a rapid positive inotropism in isolated left atrium of male rats. Upon short-term exposure to androgens, an increase in intracellular cAMP levels has been observed, though delayed with respect to the time course of contraction, suggesting that other mechanisms may participate in initiating the contraction. Therefore, the interaction of positive inotropism elicited by ouabain, an inhibitor of Na(+)-K(+)-ATPase, and androgens was studied in isolated left atrium of rat. Androgens antagonized ouabain-elicited positive inotropism and increased the basal tone. Vanadate, an inhibitor of the Ca(2+) pump, produced a similar effect as androgens on ouabain-elicited positive inotropism. Therefore, androgens might interact with the Ca(2+) pump and this may explain the increase in basal tone. The conjugation of 5 alpha-dihydrotestosterone with bovine serum albumin produced the same effect, suggesting an extracellular interaction of androgens inhibiting the Na(+)-K(+)-ATPase that could increase intracellular Ca(2+) via the Na(+)-Ca(2+) exchange.

Development of high-oleic, low-linolenic acid Ethiopian-mustard (Brassica carinata) germplasm

Seed oil of current zero erucic-acid germplasm of Ethiopian mustard ( Brassica carinata A. Braun) is characterized by a low concentration of oleic acid and high concentrations of linoleic and linolenic acids. Sources of increased oleic-acid (HO) and reduced linolenic-acid (LL) concentration have been developed separately in high erucic-acid germplasm. The objectives of the present research were to study the inheritance of the HO and LL traits in crosses HO x LL, and to develop HOLL recombinants, both in high erucic-acid and zero erucic-acid backgrounds. The HO mutant N2-3591 (about 20% oleic acid compared to 9% in conventional high erucic-acid materials), was reciprocally crossed with the LL lines N2-4961 and HF-186 (both with about 5% linolenic acid compared to 12% in standard high erucic-acid materials). Increased oleic acid concentration of N2-3591 was found to be controlled by alleles at one locus (Ol), whereas three different loci for reduced linolenic-acid concentration (Ln, Ln1 and Ln2) were identified in N2-4961 and HF-186. Crosses between N2-3591 and N2-4961 generated HOLL recombinants where levels of increased oleic-acid and reduced linolenic-acid were similar to those of the parents. However, a transgressive segregation for oleic acid was observed in crosses between N2-3591 and HF-186, where F(2) seeds with up to 29.7% oleic acid were obtained, in comparison to an upper limit of 25.1% in the N2-3591 parent grown in the same environment. The transgressive increased oleic-acid was expressed in the F(3) generation and was attributed to the presence of a second locus, designated Ol2. The transgressive trait was transferred to the zero erucic-acid line 25X-1, resulting in a zero erucic-acid germplasm with very high oleic-acid concentration (83.9% compared to 32.9% in 25X-1) and low linolenic-acid concentration (5.0% compared to 16% in 25X-1). Additionally, two other lines exhibiting different stable levels of increased oleic-acid (70.7% and 79.5%, respectively) and reduced levels of linolenic-acid (7.5% and 8.7%, respectively) were isolated.

First Report of Turnip mosaic virus in Pisum sativum in Spain

During 2001 and 2002, Pisum sativum var. vulgare plants grown as commercial crops in Almeria (southeast Spain) showed vein clearing and chlorotic mottle of leaves, leaf deformation, flower abortion, necrotic mottle and deformation of pods, and stunted plant growth. Crude sap of collected plants was mechanically inoculated on healthy pea plants which reproduced symptoms observed in the field; local necrotic lesions were produced on mechanically infected Chenopodium quinoa, C. amaranticolor, and Gomphrena globosa, systemic mosaic symptoms on Brassica napus and Nicotiana benthamiana, and local lesions plus systemic mosaic symptoms on N. clevelandii, which are all characteristic of Turnip mosaic virus (TuMV) (1). A reverse transcription-polymerase chain reaction assay using general primers for the extreme 3' end of the potyvirus genome amplified products of 750 and 1,700 bp in nucleic acid extracts from naturally infected pea plants as well as from the mechanically infected test plants. The overlapping nucleotide sequences of the products (GenBank Accession No. AJ489259) had a nucleotide sequence identity of 86.5% and a derived amino acid identity of 95.0% with several published sequences of TuMV (1). This report cites the first partial nucleotide sequence of TuMV infecting pea crops, and although natural infections of this virus in pea have been reported in Morocco (1976) and in the United States (2), to our knowledge, this is the first report of TuMV in Spain. References: (1) P. Lehmann et al. Physiol. Mol. Plant Pathol. 51:195, 1997. (2) R. Provvidenti. Plant Dis. Rep. 62:482, 1978.

Intracellular cAMP increases during the positive inotropism induced by androgens in isolated left atrium of rat

Molecular interactions of androgens with the plasma membrane may produce rapid cardiovascular effects that cannot be explained by the classic genomic mechanisms. In this sense, 5 alpha- and 5 beta-dihydrotestosterone-induced an acute positive inotropic effect in isolated left atrium of rat, an effect which may be due to cAMP-dependent mechanisms. To prove this, intracellular levels of cAMP, after exposure to androgens in the organ bath, and binding to beta(1)-adrenoceptors were evaluated. After a 4-min exposure, 5 alpha- and 5 beta-dihydrotestosterone increased cAMP levels from 3.83+/-0.61 to 6.15+/-1.1 and 11.18+/-2.4 pmol cAMP/mg of protein, respectively. These increases were inhibited by atenolol and not modified by treatment of the rats with reserpine. The androgen-induced cAMP increase seems to be produced via an extracellular interaction, because positive inotropism and raised levels of cAMP were produced by 5 alpha-dihydrotestosterone conjugated with bovine serum albumin (BSA). In addition, it is independent of beta(1)-adrenoceptor activation, because neither androgen displaced [(3)H]dihydroalprenolol binding. Therefore, the androgens induced a positive inotropic effect via a postsynaptic effect that increases intracellular levels of cAMP. This effect is modulated by transcriptional mechanisms or by a protein with a short half-life.

Characterization of the nirK gene encoding the respiratory, Cu-containing nitrite reductase of Bradyrhizobium japonicum

The structural gene, nirK, for the respiratory Cu-containing nitrite reductase from Bradyrhizobium japonicum USDA110 has been isolated and sequenced. The deduced amino acid sequence exhibited a high degree of similarity to other Cu-containing nitrite reductases from various sources. The full-length protein included a signal peptide for protein export. Analysis of the sequence upstream from the structural nirK gene revealed the presence of an anaerobox located 83 base pairs from the putative translational start codon. Cells of strain GRK308, a nitrite reductase-deficient derivative of strain USDA110, were unable to grow when cultured under microaerobic conditions (1% O(2)) in the presence of either nitrate or nitrite. Maximal expression of a nirK-lacZ fusion in strain USDA110 required simultaneously both low level oxygen conditions and the presence of nitrate. Expression of beta-galactosidase activity was not detected in the B. japonicum fixL 7403, fixJ 7360 and fixK(2) 9043 mutants transformed with the nirK-lacZ fusion after incubation of the cells under oxygen-limiting conditions either with or without nitrate. Complementation of B. japonicum 9043 with the fixK(2) gene restored beta-galactosidase activity to levels similar to those found in the parental strain. These results suggest that nirK expression depends on the low-oxygen-responsive two-component regulatory system FixLJ and on the Fnr/FixK-like DNA binding protein FixK(2).

First Report of Cucumber leaf spot virus in Spain

Cucumber leaf spot virus (CLSV), reclassified as a species in the new genus Aureusvirus (family Tombusviridae) (1), has ≈30-nm isometric particles with a ≈4.4-kb positive-sense, single-stranded RNA. CLSV is transmitted by the chytrid fungus Olpidium bornovanus. The virus has been reported in Germany, Great Britain, Greece, Jordan, and Saudi Arabia. During the fall of 2000, abundant chlorotic spots with necrotic centers were observed on the leaves of cucumber plants grown in a commercial greenhouse in Granada (southeastern Spain). When sap from collected leaves was used to mechanically inoculate cucumber, symptoms were reproduced and were suggestive of CLSV. Based on the nucleic acid sequence of CSLV (2), the following specific primers were designed: CLSVU1440 (5'-AAGGTAGGGGAGATCTTG-3') and CLSVA2160 (5'-GCTTCGGCTGATTCTGA-3'). When used in reverse transcription-polymerase chain reactions (RT-PCR), leaves expressing symptoms yielded amplification products of the expected size (720 bp). These products were cloned into a pGEM-T vector and sequenced (GenBank Accession No. AY038365). The similarity of the nucleic acid and derived amino acid sequences with the one published for CLSV (2) was 94.5 and 99.1%, respectively. The amino acid sequence was 86% identical to that of Pothos latent virus (GenBank Accession No. AJ243370). Ten cucumber plants grown in vermiculite supplemented with rhizosphere soil (1/30, vol/wt) from infected plants developed symptoms on leaves after 1 month and were positive for CLSV when leaf and root tissues were analyzed by RT-PCR and Southern blot hybridization. Plants grown in vermiculite alone did not become infected with CLSV. Microscopic examination of root tissue revealed O. bornovanus only in infected plants. To our knowledge, this is the first record of CSLV in Spain. References: (1) G. P. Martelli et al. Arch. Virol. 143:1847, 1998. (2) J. S. Miller et al. Virus Res. 52:51, 1997.

First Report of Cucumber vein yellowing virus in Spain

In the autumn of 2000, an outbreak of a disease caused considerable losses in greenhouse cucumber crops in Almeria (Spain). Infected plants showed vein clearing followed by chlorosis in leaves and yellow/green chlorotic spots on fruits. These symptoms as well as the presence of Bemisia tabaci in the crops suggested the possible involvement of Cucumber vein yellowing virus (CVYV), a proposed member of the Potiviridae family, which was first described in 1960 in Cucumis spp. from Israel (1). B. tabaci populations and leaves from cucumber plants were collected from the greenhouses and analyzed by RT-PCR using specific primers (CV(+): 5'-AGCTAGCGCGTATGGGGTGAC-3'; CV(-): 5'-GCGCCGCAAGTGCAA-ATAAAT-3') that we designed based on the partial sequence published for CVYV (2). Total nucleic acid extracts from both B. tabaci individuals and the collected plants yielded amplification products of the expected size (449 bp), which were cloned and sequenced (Genebank accession number AJ301640). The sequence was 95.6% identical to that previously reported for CVYV. Nonviruliferous B. tabaci whiteflies were given a 24-h acquisition period on symptomatic leaves and then placed in groups of 15 insects on each of 10 healthy cucumber plants at the 4 leaf-stage for a 24-h inoculation period. Inoculated and control plants were analyzed 1 week later and the infection with CVYV was confirmed (10/10) by RT-PCR. Doublestranded RNA extractions from field-collected samples and from plants inoculated under controlled conditions suggested that no dsRNA formation was associated with the infection. This is the first report of CVYV in Spain. References: (1) S. Cohen and F. E. Nitzany. Phytopathol. Medit. 1:44, 1960. (2) H. Lecoq et al. J. Gen. Virol. 81:2289, 2000.

delta(9)-Tetrahydrocannabinol increases nerve growth factor production by prostate PC-3 cells. Involvement of CB1 cannabinoid receptor and Raf-1

Cannabinoids, the active components of marihuana, exert a variety of effects in humans. Many of these effects are mediated by binding to two types of cannabinoid receptor, CB1 and CB2. Although CB1 is located mainly in the central nervous system, it may also be found in peripheral tissues. Here, we study the effect of cannabinoids in the production of nerve growth factor by the prostate tumor cell line PC-3. We show that addition of Delta(9)-tetrahydrocannabinol to PC-3 cells stimulated nerve growth factor production in a dose-dependent and time-dependent manner. Maximal effect was observed at 0.1 microM Delta(9)-tetrahydrocannabinol and 72 h of treatment. Stimulation was reversed by the CB1 antagonists AM 251 and SR 1411716A. Pre-treatment of cells with pertussis toxin also prevented the effect promoted by Delta(9)-tetrahydrocannabinol. These results indicate that Delta(9)-tetrahydrocannabinol stimulation of nerve growth factor production in these cells was mediated by the cannabinoid CB1 receptor. The implication of Raf-1 activation in the mode of action of Delta(9)-tetrahydrocannabinol is also suggested.

One of two hemN genes in Bradyrhizobium japonicum is functional during anaerobic growth and in symbiosis

Previously, we screened the symbiotic gene region of the Bradyrhizobium japonicum chromosome for new NifA-dependent genes by competitive DNA-RNA hybridization (A. Nienaber, A. Huber, M. Göttfert, H. Hennecke, and H. M. Fischer, J. Bacteriol. 182:1472-1480, 2000). Here we report more details on one of the genes identified, a hemN-like gene (now called hemN(1)) whose product exhibits significant similarity to oxygen-independent coproporphyrinogen III dehydrogenases involved in heme biosynthesis in facultatively anaerobic bacteria. In the course of these studies, we discovered that B. japonicum possesses a second hemN-like gene (hemN(2)), which was then cloned by using hemN(1) as a probe. The hemN(2) gene maps outside of the symbiotic gene region; it is located 1.5 kb upstream of nirK, the gene for a Cu-containing nitrite reductase. The two deduced HemN proteins are similar in size (445 and 450 amino acids for HemN(1) and HemN(2), respectively) and share 53% identical (68% similar) amino acids. Expression of both hemN genes was monitored with the help of chromosomally integrated translational lacZ fusions. No significant expression of either gene was detected in aerobically grown cells, whereas both genes were strongly induced (> or = 20-fold) under microaerobic or anaerobic conditions. Induction was in both cases dependent on the transcriptional activator protein FixK(2). In addition, maximal anaerobic hemN(1) expression was partially dependent on NifA, which explains why this gene had been identified by the competitive DNA-RNA hybridization approach. Strains were constructed carrying null mutations either in individual hemN genes or simultaneously in both genes. All mutants showed normal growth in rich medium under aerobic conditions. Unlike the hemN(1) mutant, strains lacking a functional hemN(2) gene were unable to grow anaerobically under nitrate-respiring conditions and largely failed to fix nitrogen in symbiosis with the soybean host plant. Moreover, these mutants lacked several c-type cytochromes which are normally detectable by heme staining of proteins from anaerobically grown wild-type cells. Taken together, our results revealed that B. japonicum hemN(2), but not hemN(1), encodes a protein that is functional under the conditions tested, and this conclusion was further corroborated by the successful complementation of a Salmonella enterica serovar Typhimurium hemF hemN mutant with hemN(2) only.

Fatty acids and tocochromanols in seeds of Orobanche

The evaluation of tocochromanols (tocopherols and tocotrienols) in 49 accessions from 21 Orobanche species revealed three well separated groups. The first one, characterized by high gamma-tocotrienol content, included all the accessions of sect. Orobanche. The second one, exhibiting high gamma-tocopherol content, comprised the accessions of O. arenaria Borkh. and O. purpurea Jacq. (sect. Trionychon Wallr.). All the other accessions of this section presented high delta-tocopherol content. Differences for tocochromanol derivatives within sect. Trionychon were paralleled by differences in the fatty acid profile, with the high delta-tocopherol class having also a higher oleic to linoleic acid ratio.

Mass spectrometric detection and identification of ortho, para-benzyltoluenes and oligotoluenes

Mass spectrometric detection and identification of ortho- and para-benzyltoluenes and oligotoluenes, C(21)-C(49), in several reaction mixtures was performed. Thus, the corresponding electron impact spectra were acquired and analyzed, this in addition to constant B/E linked scans and high-resolution data. Copyright 2000 John Wiley & Sons, Ltd.

Mass spectrometric study of tricarbonyl (eta(6)-phenyl methanols) of chromium(0)

A mass spectrometric study of several tricarbonyl (eta(6)-phenyl methanols) of chromium(0) was performed. Electron ionization (EI), chemical ionization (CI) and fast atom bombardment (FAB) mass spectra were acquired for each molecule, and compared in order to establish a general fragmentation pattern. The suggested pathways were investigated and confirmed by means of constant b/e linked scans and high resolution data. In addition a Hammett-McLafferty correlation for some peaks derived from the molecular ions was accomplished.

Characterization of Bradyrhizobium japonicum pcaBDC genes involved in 4-hydroxybenzoate degradation

The pca structural genes encode enzymes that participate in the conversion of protocatechuate to succinate and acetylcoenzyme A. A 3. 05-kb region of the Bradyrhizobium japonicum strain USDA110 genome has been characterized, which contains the pcaB, pcaD and pcaC genes. The predicted protein sequences of the three genes have extensive homologies with beta-carboxy-cis,cis-muconate cycloisomerase (PcaB), beta-ketodiapate enol-lactone hydrolase (PcaD), and gamma-carboxymuconolactone decarboxylase (PcaC), respectively, from Acinetobacter calcoaceticus and Pseudomonas putida. The DNA sequence revealed that the pca genes are probably arranged in a single transcriptional unit, pcaBDC, similar to that described in P. putida. A pcaB deletion mutant constructed by marker exchange mutagenesis lost the ability to use 4-hydroxybenzoate or protocatechuate as the only carbon source, demonstrating functionality of the characterized genes in catabolism of hydroxyaromatics by B. japonicum. Furthermore, 4-hydroxybenzoate and protocatechuate became toxic for the pcaB mutant, indicating that hydroxyaromatics catabolism serves both nutritional and detoxifying purposes.

Within-plant variation for seed weight and seed quality traits in white lupin (Lupinus albus L.)

The influence of the branch order on seed weight and seed quality traits was studied in 32 bitter landraces of white lupin. Seeds from the mainstem, first-order branches, and second-order branches were harvested separately and the seed weight, protein content, oil content, and oil composition were determined at each branch order. The results showed the presence of within-plant variation for all of the traits included in this study. The seeds from the mainstem were heavier and had lower oil and protein content than the seeds from the branches. The seed oil from the mainstem was characterised by a higher percentage of saturated fatty acids and oleic acid, and a lower percentage of linoleic, linolenic, eicosenoic, and erucic acid than the seeds from the branches. The seeds from the first branch order were heavier and had lower oil and protein content than the seeds from the second-order. Seed oil from the 2 branch orders only differed for the percentage of palmitic acid, which was higher in the first-order. It is concluded that within-plant variation in white lupin should be taken into account to avoid sampling errors, because seeds from one branch order are imperfect as a predictor of the composition of seeds from the others.

Biocatalytic oxidation of polycyclic aromatic hydrocarbons by hemoglobin and hydrogen peroxide

Hemoglobin is able to oxidize polycyclic aromatic hydrocarbons, PAH's, in presence of hydrogen peroxide. Among 12 aromatic compounds tested, six were oxidized; anthracene, carbazole, dibenzothiophene, fluorene, 9-hexylanthracene and pyrene. The products were identified as aromatic ketones and sulfoxides. Effect of organic solvent concentration and hemoglobin stability were determined.

vnd, a gene required for early neurogenesis of Drosophila, encodes a homeodomain protein

The development of the central nervous system in Drosophila is initiated by the segregation of neuroblasts, the neural progenitors, from the embryonic neuroectoderm. This process is guided by at least two classes of genes: the achaete-scute complex (AS-C) proneural genes and the neurogenic genes. It has been known for some time that loss-of-function mutations in the AS-C result in neural hypoplasia and the first observed defect is failure of segregation of a fraction of neuroblasts. Loss-of-function mutations at the ventral nervous system defective (vnd) locus are known to lead to similar phenotypic defects in early neurogenesis. More recently, the vnd locus has been implicated in the regulation of the proneural AS-C genes and the neurogenic genes of the Enhancer of split complex. In this paper we report the identification of a transcript associated with the vnd locus, the transcript distribution in embryogenesis, which is compatible with the nervous system mutant phenotypes described for this gene, and that the protein product is a member of the NK-2 homeodomain family. We discuss these findings within the framework of early Drosophila neurogenesis and the known phenotypes associated with the vnd locus.