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API-mass spectrometry of polyketides. I. A study on the fragmentation of triketide lactones.

The fragmentation of delta-lactones, particularly triketide lactones, has been studied to provide information on the behavior of polyketides under atmospheric pressure ionization mass spectrometry (API-MS). The principal fragmentation patterns of triketide lactones are characterized by two sequential dehydrations followed by loss of CO to give hydrocarbon fragments. A particular goal of this study was an understanding of the origins of the two water molecules from the dehydrations. 18O- and 2H-isotope labeling experiments with delta-valerolactone suggest a mechanism for lactone fragmentation in which ionization by proton transfer is followed by rapid equilibration of ring-opened and ring-closed forms, which results in exchange of the ionizing proton into the hydrocarbon framework of the compound and randomization of the oxygens of the lactone. Subsequent fragmentation primarily involves sequential loss of water and CO. Similar experiments with the more complex triketide lactones show that their mass spectra share common features with that of delta-valerolactone, together with an additional water loss from the 3-hydroxyl group.

Genetic Engineering↗

Development of dopamine-immunoreactive neurons associated with the antennal lobes of the honey bee, Apis mellifera.

This report examines the development of the dopaminergic system in the primary antennosensory centres (antennal lobes) of the brain of the honey bee, Apis mellifera, and the effects of dopamine on neurite outgrowth of antennal-lobe neurons in vitro. Antibodies raised against dopamine were used to follow the development of a small population of dopamine-immunoreactive neurons that invade the antennal lobes during metamorphic adult development. Immunopositive somata associated with the antennal lobes were first detected at stage 2 of the nine stages of metamorphic adult development, but processes of these neurons within the antennal-lobe neuropil did not exhibit immunostaining until pupal stage 3. Severe depletion of primary sensory input to the right antennal lobe early in metamorphic adult development or removal of the right antenna from newly emerged bees did not alter the expression of dopamine immunoreactivity in the antennal-lobe neuropil. The presence of dopamine in developing antennal lobes was confirmed by using high performance liquid chromatography with electrochemical detection. Levels of dopamine were significantly higher at pupal stage 4 than at all other stages examined. This surge in dopamine levels coincided with rapid growth and compartmentalisation of the antennal-lobe neuropil. Exogenously applied dopamine (50 microM) enhanced the growth of antennal-lobe neurons in vitro, but only in cells derived from pupae at stage 5 of metamorphic adult development. The early appearance of dopamine-immunoreactive neurons and the effects of dopamine on stage 5 antennal-lobe neurons in vitro support the view that dopamine plays a role in the developing brain of the honey bee.

Analysis of Variance↗

Reversible downregulation of protein kinase A during olfactory learning using antisense technique impairs long-term memory formation in the honeybee, Apis mellifera.

In this study, we examined the role of cAMP-dependent protein kinase (PKA) in associative olfactory learning of the honeybee, Apis mellifera. In the bee, specific interference with molecules to clarify their role in a certain behavior is difficult, because genetic approaches, such as mutants or transgenic animals, are not feasible at the moment. As a new approach in insects in vivo, we report the use of short antisense oligonucleotides. We show that phosphorothioate-modified oligodeoxynucleotides complementary to the mRNA of a catalytic subunit of PKA directly injected into the bee brain cause a reversible and specific downregulation of both the amount of the catalytic subunit and of PKA activity by 10-15%. The amounts of the regulatory subunit of PKA, as well as PKC, are not affected. The slight "knockdown" of PKA activity during the training procedure, a classical olfactory conditioning of the proboscis extension reflex, neither affects acquisition nor memory retention 3 or 6 hr after training. However, it causes an impairment of long-term memory retention 24 hr after training. Downregulation of PKA 3 hr after training has no detectable effect on memory formation. We conclude that PKA contributes to the induction of a long-term memory 24 hr after training when activated during learning. Second, we demonstrate that the antisense technique is feasible in honeybees in vivo and provides a new and powerful tool for the study of the molecular basis of learning and memory formation in insects.

Animals↗

[Comparative evaluation of bacteria identification from the Acinetobacter genus using a commercially available API 20NE system, PCR and RFLP techniques].

A study was carried out for identification of 50 Acinetobacter strains isolated from various clinical materials. Using classic methods the following species were identifies: Acinetobacter sp. (68%), Acinetobacter baumanii (24%) and Acinetobacter lwofii (8%). In all strains the recA gene was found of 435-500 pz size which confirms their belonging to that genus. Amplification products were digested with restriction enzymes Mbol and HinfI (RFLP) and their detection was carried out on agarose gel by electrophoresis methods, owing to that the arrangement of gene fragment characteristic of each strain was obtained. After careful analysis restriction patterns were obtained corresponding to the following genome species: Acinetobacter baumanii (60%), Acinetobacter sp. 3 (28%) and Acinetobacter lwoffii (12%). The methods of molecular biology made possible a more precise classification of the studied strains according to species. Certain strains determined as Acinetobacter sp. by the API 20NE system were found to be Acinetobacter baumanii, Acinetobacter sp. 3 or Acinetobacter lwofii when determined by the PCR/RFLP method.

Acinetobacter↗

Utilization of bee (Apis mellifera) honey for vinegar production at laboratory scale.

Vinegar was obtained from bee (Apis mellifera) honey. The wort was prepared by diluting honey in distilled water to 21% total solids and by adding ammonium sulfate and ammonium phosphate. Saccharomyces cerevisiae was inoculated to the wort (4 g/L). Ethanol production was carried out at room temperature during 84 hours. In this study, 1 Kg of honey yielded about 5 L of wine, containing 8% alcohol (v/v), from a wort with 17.11% total sugars (w/v). The efficiency of the alcoholic fermentation was 81.34%. The acetic fermentation with an inoculum of mixed acetic microorganisms was performed by quick process in a 15 L vertical fermenter. This resulted in a vinegar containing up to 9% of acetic acid (w/v) and about 1% of alcohol (v/v). The acetic fermentation yielded between 91.24 and 97.21%. Approximately 5 L of honey vinegar with 9% acetic acid (w/v) were obtained from 1 Kg of bee honey. All attributes of honey vinegar showed acceptability index over 70%: 95.37% for appearance, 94.81% for color, 79.07% for odor and 75.56% for flavor, indicating it would show good consumer acceptability.

Acetic Acid↗

[Polymorphism of locus COI-COII of mitochondrial DNA in the honeybee Apis mellifera L. from southern Ural region].

In spite of high biodiversity within the honeybee species Apis mellifera L., only one geographical race, the dark-colored forest honeybee A. m. mellifera, is uniquely adapted to severe environmental conditions of Eurasian forest and forest-steppe zones. Within the vast range of this race, only single isolates remain, where the dark forest honeybee is purebred. The Bashkir population is supposed to be one of these isolates. Molecular-genetic assessment of the state of the gene pool of this population revealed that southern honeybee races were introduced into the Bashkortostan Republic with great intensity, which was above the assimilation capacity of the population. The main part of the former range of the Bashkir population represents a hybrid zone with approximately equal ratio between gene pools of local and introduced honeybees. Our studies provide the possibility to single out one extant reserve of A. m. mellifera, Burzyanskii raion, in which the proportion of local bees in the gene pool is 0.98.

Animals↗

Polliniferous plants and foraging strategies of Apis mellifera (Hymenoptera: Apidae) in the Yucatán Peninsula, Mexico.

A study of the most important polliniferous plants for European and Africanized honeybees (Apis mellifera L.) was made in Quintana Roo state. Comparisons were made between the plants visited by both bee types in order to determine whether there were qualitative or quantitative differences in their choice of plant species. Also some foraging strategies of the honeybees were analysed. Pollen from pollen load samples was acetolysed and mounted on slides. Subsequently the pollen grains were identified, counted and photographed. A total of 206 pollen load samples were collected at Palmas and St. Teresa during two years. The most frequent species in the pollen load samples from European and Africanized honeybees were Cecropia peltata, Metopium brownei, Lonchocarpus sp. 2, Viguiera dentata, Eragrostis sp. 1, Bursera simaruba and Eupatorium albicaule. Both types of honey bees show a high reliance on pollen from only a few species, the first five named above comprised around 50% of all the mean percentage frequencies. Families that contributed with the largest number of pollen species were Fabaceae, Asteraceae, Boraginaceae, Convolvulaceae, Euphorbiaceae, Sapindaceae, Poaceae, Myrtaceae, Sapotaceae and Tiliaceae. C. peltata, Trema micrantha, B. simaruba, Eugenia sp. 1, Thouinia canesceras, Pouteria sp. 1, Mimosa bahamensis and V. dentata, were the pollen species with the largest percentages of occurrence in both European and Africanized bee pollen load samples, and also represent a "long-term" food resources during the year.

Animals↗

Ultrastructural alterations in cortex of adrenal gland caused by the toxic effect of bee (Apis mellifera) venom.

Bee accidents incidence is underestimated because many people do not consult to the physicians. Here it is described for the first time the severe mice adrenal gland damage induced by Apis mellifera venom. Biopsy specimens were obtained from mice adrenal gland and after sample preparation observed in Hitachi H-7100 electron microscope. In this work the ultrastructural analysis showed, 6 h after injection, a non homogeneous smooth endothelial reticulum, and in some places loss of plasma membrane. The fenestrae spaces were bigger and detritus in the capillary lumen were observed. Erythrocytes were seen in a cortical cell. After 48 h of venom injection, expanded fenestrae were observed. Capillary basal membrane was interrupted. Myelin-like figures and autophagic vacuoles were noticed. Swollen smooth endoplasmic reticulum elements and endothelial unfolding to the light were seen. Moreover, swollen Golgi and mitochondria were observed, in some places forming myelinic-like figures. At 144 h after venom injection, widened spaces were noticed in capillary fenestrae. Cellular section showed swollen and lost smooth endoplasmic reticulum elements. Smooth endoplasmic reticulum tubules disappearance suggested non steroidogenesis. In conclusion, we suggest that some of the bee envenoming human clinical manifestations, as is observed in mice, are determined by suprarenal gland damage produced by toxins present in this venom.

Adrenal Cortex↗

[Detection of extended-spectrum beta-lactamases by the rapid ATB E technique. Value of the API V2.1.1 expert system].

Twenty-two extended-spectrum betalactamase-producing strains of enterobacteriaceae recovered in the authors' hospital were tested using the Rapid ATB E coupled with the API V2.1.1. expert system. The expert system detected 90.9% of ESBL-producing strains. Two strains producing a SHV2 and a CTX1, respectively, escaped detection by the expert system despite concomitant resistance to aminoglycosides.

4-Quinolones↗

[Comparison of efficacy of three test-systems for identification of Staphylococcus: PBDS (Russia), "STAPHYtest-16" (Check Republic), "API-STAPH" (France)].

The diagnostic efficiency of three test-systems designed for staphylococci identification including the definition of opportunistic errors was comparatively studied. The identification results coincidence (IRC) made, versus the reference method, 57 +/- 14% for Staphylococci Differentiation Biochemical Plate (SDBP--Russia) 73.83 +/- 3.6% for STAPHYtest-16 (Check Republic) and 58.33 +/- 5.03% for API-Staph (France). The diagnostic efficiency of the studied test-systems was found to be in proportion with the total information density of the identification tests belonging to each of them, which could be used for determining an optimal test list that would ensure the maximum diagnostic effect with minimal cost.

Bacteriological Techniques↗

Cellular and subcellular changes in muscle, neuromuscular junctions and nerves caused by bee (Apis mellifera) venom.

Biopsy specimens of cervico-scutular muscles obtained from animals injected with bee crude venom were prepared for electron microscopy studies. At 6 h from Apis mellifera venom injection, in mice under transmission electron microscopy, the muscular fibres presented different atrophy levels with increment of the intermyofibrillar spaces. Tubules and sarcoplasmic reticulum elements were altered, in some places only tubular fragments and an increment of the intermyofibrillar spaces were noticed as well as loss of fibre regularity and prominent triads. In subsarcolemma region, areas lacking myofibrils and mitochondria damages were observed. Muscular segmental necrosis and atrophy areas were observed. Neuromuscular junctions were altered. The number of synaptic vesicles was very variable and synaptic clefts showed irregularities. A decrease in the number and arrangement of the synaptic clefts, as well as free polysomes, suggesting regeneration processes, were also observed. The myelinic nerves exhibited in the axon or in the wall vacuolisation areas. The presence of severe muscular lesions, the finding of venom activities in the presynaptic region and the detection of damages in the neuromuscular junctions at different chronological stages of our experiments indicate that the bee venom is highly toxic for neuromuscular structures.

Animals↗

Engineering and algorithm design for an image processing Api: a technical report on ITK--the Insight Toolkit.

We present the detailed planning and execution of the Insight Toolkit (ITK), an application programmers interface (API) for the segmentation and registration of medical image data. This public resource has been developed through the NLM Visible Human Project, and is in beta test as an open-source software offering under cost-free licensing. The toolkit concentrates on 3D medical data segmentation and registration algorithms, multimodal and multiresolution capabilities, and portable platform independent support for Windows, Linux/Unix systems. This toolkit was built using current practices in software engineering. Specifically, we embraced the concept of generic programming during the development of these tools, working extensively with C++ templates and the freedom and flexibility they allow. Software development tools for distributed consortium-based code development have been created and are also publicly available. We discuss our assumptions, design decisions, and some lessons learned.

Algorithms↗

Microsatellite analysis of royal jelly producing traits of Italian honeybee (Apis mellifera Liguatica).

Genetic variations at 10 microsatellite loci were surveyed to determine the evolutionary relationships and molecular characteristics of three different honeybee (Apis mellifera L.) populations from Italy and China, i. e., native Italian (Ee), Chinese-Italian (Eb) and selected high royal jelly producing bees (Ea). A total of 96 alleles,an average of 9.6 alleles per locus,were scored in Ee,Eb and Ea bees at 10 loci. Out of which 48 (5%) were different. This indicated a high degree of polymorphism and ever, some genetic differentiation among the three populations due to artificial selection and geographical isolation. The polymorphic information contents (PIC) and heterozyosity of the three populations at 10 loci were 0.57, 0.50, 0.57, and 0.60, 0.57, 0.61, for Ee, Eb, Ea populations respectively, neither of which were different. This indicated same gene diversity within the three populations. The genetic distance was shorter between Ee and Eb bees as well as between Eb and Ea bees. Whereas that between Ee and Eb bees was longer. Further analysis indicated that the allele frequency of seven alleles at six loci (159 bp at A29,100 bp and 104 bp at A24; 110 bp at A7; 126 bp at A43, 221 bp at A14 and 221 bp at A113) increased going from Ee to Eb to Ea bees. Paired tests showed significant higher allele frequency between Ea and Eb bees,as well as between Ea and Eb bees. This indicates that these seven alleles are likely molecular markers of the high royal jelly producing bees. In addition,the allele frequency of four alleles at four loci (106 bp at A24,140 bp at A43;215 bp at A113 and 219 bp at A14) decreased going from Ea bees to Eb to Ee. Paired tests indicated significant lower allele frequency between Ea and Ee bees,as well as between Ea and Eb bees. Those four alleles may be the genetic markers for low royal jelly production.

Alleles↗

Hydrolases in the hypopharyngeal glands of workers of Scaptotrigona postica and Apis mellifera (Hymenoptera, Apinae).

Hydrolytic enzymes from hypopharyngeal gland extracts of newly emerged, nurse and foraging workers of two eusocial bees, Scaptotrigona postica, a native Brazilian stingless bee, and the Africanized honey bee (Apis mellifera) in Brazil, were compared. The hypopharyngeal gland is rich in enzymes in both species. Fifteen different enzymes were found in the extracts, with only a few quantitative differences between the species. Some of the enzymes present in the extracts may have intracellular functions, while others seem to be digestive enzymes. Scaptotrigona postica, had lower beta-glucosidase and higher lipase esterase activities than A. mellifera. The differences may be due to different feeding habits and behavioral peculiarities of the two species.

Animals↗

Characters that differ between diploid and haploid honey bee (Apis mellifera) drones.

Diploid males have long been considered a curiosity contradictory to the haplo-diploid mode of sex determination in the Hymenoptera. In Apis mellifera, 'false' diploid male larvae are eliminated by worker cannibalism immediately after hatching. A 'cannibalism substance' produced by diploid drone larvae to induce worker-assisted suicide has been hypothesized, but it has never been detected. Diploid drones are only removed some hours after hatching. Older larvae are evidently not regarded as 'false males' and instead are regularly nursed by the brood-attending worker bees. As the pheromonal cues presumably are located on the surface of newly hatched bee larvae, we extracted the cuticular secretions and analyzed their chemical composition by gas chromatograph-mass spectrometry (GC-MS) analyses. Larvae were sexed and then reared in vitro for up to three days. The GC-MS pattern that was obtained, with alkanes as the major compounds, was compared between diploid and haploid drone larvae. We also examined some physical parameters of adult drones. There was no difference between diploid and haploid males in their weight at the day of emergence. The diploid adult drones had fewer wing hooks and smaller testes. The sperm DNA content was 0.30 and 0.15 pg per nucleus, giving an exact 2:1 ratio for the gametocytes of diploid and haploid drones, respectively. Vitellogenin was found in the hemolymph of both types of imaginal drones at 5 to 6 days, with a significantly lower titer in the diploids.

Animals↗

A novel approach for the management of the chalkbrood disease infesting honeybee Apis mellifera L. (Hymenoptera: Apidae) colonies in Egypt.

Except for, very few articles regarding the influence of some organic acids on the causative pathogen, Ascosphaera apis Maassen, no other studies pertaining to the management of the chalkbrood disease were performed, so far in Egypt. Laboratory investigations indicated that the fungicides, i.e (Galben C 46%, Radomil gold pluse WP 42.5% and Daconil 2787) at their recommended rates did not exert any effect on the mycelical growth of the fungus. Therefore, these fungicides were completely excluded from the subsequent apiary trials. As to the Mycostatin, it was found clearly that this mycostatic compound was effective at the rates of 50.000 and 100.000 IU. Regarding the essential oils (ceder, clove, peppermint, parsley, black cumin, garden rocket, and ricin), ceder oil surpassed the other oils and materials in controlling the subject disease. It is peculiar that no studies on the efficacy of ceder are available in the literature, so the present work using ceder oil is recorded for the first time worldwide. Thymol substance at the rate of 2% showed also a great success in managing the CHB disease. Baised on the obtained results, the promising materials in controlling the disease could be arranged according to their efficacy in a descending order as follows: ceder oil>thymol>mycostatin and oxalic acid, so these highly effective materials were again tested under the apiary conditions. Outdoors (apiary) studies revealed that ceder oil 4% gave 100% reduction in mummies numbers. Reductions in number of fallen mummies ranged from 63.22 to 96.94, 18.93 to 81.74, and 10.11 to 68.16%, on average, for thymol, mycostatin, and oxalic acid, respectively. From the practical point of view, thymol could be recommended for controlling the CHB disease, as it is the cheapest material and proved to increase the brood nest as well. In addition, thymol has other uses in the field of apiculture.

Animals↗

A comparative analysis of highly conserved sex-determining genes between Apis mellifera and Drosophila melanogaster.

A comparison of the most conserved sex-determining genes between the fruit fly, Drosophila melanogaster, and the honey bee, Apis mellifera, was performed with bioinformatics tools developed for computational molecular biology. An initial set of protein sequences already described in the fruit fly as participants of the sex-determining cascade was retrieved from the Gene Ontology database (http://www.geneontology.org/) and aligned against a database of protein sequences predicted from the honey bee genome. The doublesex (dsx) gene is considered one of the most conserved sex-determining genes among metazoans, and a male-specific partial cDNA of putative A. mellifera dsx gene (Amdsx) was identified experimentally. The theoretical predictions were developed in the context of sequence similarity. Experimental evidence indicates that dsx is present in embryos and larvae, and that it encodes a transcription factor widely conserved in metazoans, containing a DM DNA-binding domain implicated in the regulation of the expression of genes involved in sexual phenotype formation.

Animals↗

The total protein content, protein fractions and proteases activities of drone prepupae of Apis mellifera due to varrosis.

The proteins level and activities of acid and alkaline proteases in whole body extracts of drone prepupae of Apis mellifera naturally infested with Varroa destructor were studied. The infested and a non-infested group did not differ significantly in their total protein content. However, some differences in protein profiles were found. A lack of three protein fractions of moderate and lower molecular weight in infested prepupae was noted. Moreover, some differences in the quantity of protein in most of the fractions were observed. The activity of acid proteases from infested prepupae was lower (p < 0.05) compared with the activity of these proteases from the non-infested one group. The infested drone had higher activity of alkaline proteases than non-infested but this difference was not statisticaly significant.

Animals↗