58 research outputs found
Prepubertaalne gonadektoomia isastel kassidel: retrospektiivne internetiküsitlusel põhinev noorte kasside kastreerimise ohutuse uuring
Graduation Thesis in Veterinary MedicinePrepubertal gonadectomy (PPG) of kittens is proven to be a suitable method for feral cat
population control, removal of unwanted sexual behaviour like spraying and aggression and
for avoidance of unwanted litters. There are several concerns on the possible negative effects
on PPG including anaesthesia, surgery and complications. The aim of this study was to
evaluate the safety of PPG. Microsoft excel was used for statistical analysis. The
information about 6646 purebred kittens who had gone through PPG before 27 weeks of age
was obtained from the online retrospective survey. Database included cats from the different
breeds and –age groups when the surgery was performed, collected in 2019. The
complications were seen in 30 (0.5%) kittens for the PPG and 60 (0.9%) of kittens developed
feline infectious peritonitis (FIP). Since there were few complications it is mostly safe to use
the PPG for purebred kittens under 27 weeks of age. T he safety of this procedure is strongly
related to the veterinarian’s experience and skills. There was no clear link between the
complications and FIP connected to the PPG. Considering the data of this study, the breed
population might not be in all the cases large enough to be adjustable for representing the
breed outside this studyPrepubertaalne kastreerimine (prepubertal gonadectomy. PPG) on tõhus meetod
kodutute kasside populatsiooni arvukuse piiramiseks, soovimatu sugulise käitumise
nagu territooriumi märgistamine ja agressioon vältimiseks ning soovimatute
pesakondade sünni vältimiseks. Anesteesia, kirurgia ning komplikatsioonid on mõned
põhjused, mis tekitavad inimestes hetkel kahtlusi PPG kasutamiseks. Käesoleva
uuringu eesmärk on hinnata PPG turvalisust. Uuringus kasutatav andmebaas on
kogutud 2019. aastal internetipõhise retrospektiivse küsimustiku abil ja hõlmab endas
6646 kassi andmeid, kes olid kastreeritud enne 27. Elunädalat. Statistilise analüüsi
teostamiseks kasutati programmi Microsoft Excelit. PPG tõttu esines komplikatsioone
30 (0.5%) kassil ning 60 (0.9%) kassil arenes kahe aasta jooksul välja kasside nakkuslik
peritoniit (feline infectious peritonitis, FIP). Vähene komplikatsioonide arv näitab, et
PPG on enamasti turvaline valik noorte kasside kastreerimiseks ja PPG
komplikatsioonide esinemine on suurel määral seotud loomaarsti kogemuste ja
oskustega selle protseduuri läbi viimisel. Antud uuringust ei selgunud, et PPG võiks
mõjutada FIPi esinemist. Arvestades väikest komplikatsioonide esinemist ja vähest
vastuste arvu mõne tõu kohta, ei olnud võimalik anda usaldusväärset hinnangut PPG
riskiteguritest tõugude lõikes
Combining 1,4-dimethoxybenzene, the major flower volatile of wild strawberry Fragaria vesca, with the aggregation pheromone of the strawberry blossom weevil Anthonomus rubi improves attraction
The aggregation pheromone of strawberry blossom weevil [Anthonomus rubi Herbst (Col.: Curculionidae)], a 1:4:1 blend of Grandlure I, II and racemic lavadulol, has been available for pest monitoring for several years but shows low attractancy. Attempts to control A. rubi using the pheromone alone were also unsuccessful. This paper reports the finding that addition of the major flower volatile from wild strawberry flowers [Fragaria vesca L. (Rosaceae)], 1,4-dimethoxybenzene (comprising 98% of the volatiles emitted from wild strawberry flowers), to the aggregation pheromone increased trap catches by over two fold compared to the pheromone alone. There was no significant difference between the response of overwintered or summer emerged adults. Field trials in 2007-2008 in central and southern Norway, Denmark and southern England used green funnel traps with white cross vanes for the evaluations. (-)-Germacrene D, previously shown to be emitted by plants in increased amounts in the presence of pheromone producing weevils, did not improve trap catches. Thus, the combined use of the aggregation pheromone and 1,4-dimethoxybenzene is promising for improved monitoring and possibly control of this important pest of strawberry
Benzyl Isothiocyanate, a Major Component from the Roots of Salvadora Persica Is Highly Active against Gram-Negative Bacteria
Plants produce a number of antimicrobial substances and the roots of the shrub Salvadora persica have been demonstrated to possess antimicrobial activity. Sticks from the roots of S. persica, Miswak sticks, have been used for centuries as a traditional method of cleaning teeth. Diverging reports on the chemical nature and antimicrobial repertoire of the chewing sticks from S. persica led us to explore its antibacterial properties against a panel of pathogenic or commensal bacteria and to identify the antibacterial component/s by methodical chemical characterization. S. persica root essential oil was prepared by steam distillation and solid-phase microextraction was used to sample volatiles released from fresh root. The active compound was identified by gas chromatography-mass spectrometry and antibacterial assays. The antibacterial compound was isolated using medium-pressure liquid chromatography. Transmission electron microscopy was used to visualize the effect on bacterial cells. The main antibacterial component of both S. persica root extracts and volatiles was benzyl isothiocyanate. Root extracts as well as commercial synthetic benzyl isothiocyanate exhibited rapid and strong bactericidal effect against oral pathogens involved in periodontal disease as well as against other Gram-negative bacteria, while Gram-positive bacteria mainly displayed growth inhibition or remained unaffected. The short exposure needed to obtain bactericidal effect implies that the chewing sticks and the essential oil may have a specific role in treatment of periodontal disease in reducing Gram-negative periodontal pathogens. Our results indicate the need for further investigation into the mechanism of the specific killing of Gram-negative bacteria by S. persica root stick extracts and its active component benzyl isothiocyanate
Combining 1,4-dimethoxybenzene, the major flower volatile of wild strawberry Fragaria vesca, with the aggregation pheromone of the strawberry blossom weevil Anthonomus rubi improves attraction
Identification of iridoid synthases from Nepeta species : Iridoid cyclization does not determine nepetalactone stereochemistry
Nepetalactones are iridoid monoterpenes with a broad range of biological activities produced by plants in the Nepeta genus. However, none of the genes for nepetalactone biosynthesis have been discovered. Here we report the transcriptomes of two Nepeta species, each with distinctive profiles of nepetalactone stereoisomers. As a starting point for investigation of nepetalactone biosynthesis in Nepeta, these transcriptomes were used to identify candidate genes for iridoid synthase homologs, an enzyme that has been shown to form the core iridoid skeleton in several iridoid producing plant species. Iridoid synthase homologs identified from the transcriptomes were cloned, heterologously expressed, and then assayed with the 8-oxogeranial substrate. These experiments revealed that catalytically active iridoid synthase enzymes are present in Nepeta, though there are unusual mutations in key active site residues. Nevertheless, these enzymes exhibit similar catalytic activity and product profile compared to previously reported iridoid synthases from other plants. Notably, four nepetalactone stereoisomers with differing stereochemistry at the 4α and 7α positions – which are generated during the iridoid synthase reaction – are observed at different ratios in various Nepeta species. This work strongly suggests that the variable stereochemistry at these 4α and 7α positions of nepetalactone diastereomers is established further downstream in the iridoid pathway in Nepeta. Overall, this work provides a gateway into the biosynthesis of nepetalactones in Nepeta
Uncoupled activation and cyclization in catmint reductive terpenoid biosynthesis
Terpene synthases typically form complex molecular scaffolds by concerted activation and cyclization of linear starting materials in a single enzyme active site. Here we show that iridoid synthase, an atypical reductive terpene synthase, catalyzes the activation of its substrate 8-oxogeranial into a reactive enol intermediate, but does not catalyze the subsequent cyclization into nepetalactol. This discovery led us to identify a class of nepetalactol-related short-chain dehydrogenase enzymes (NEPS) from catmint (Nepeta mussinii) that capture this reactive intermediate and catalyze the stereoselective cyclisation into distinct nepetalactol stereoisomers. Subsequent oxidation of nepetalactols by NEPS1 provides nepetalactones, metabolites that are well known for both insect-repellent activity and euphoric effect in cats. Structural characterization of the NEPS3 cyclase reveals that it binds to NAD+ yet does not utilize it chemically for a non-oxidoreductive formal [4 + 2] cyclization. These discoveries will complement metabolic reconstructions of iridoid and monoterpene indole alkaloid biosynthesis
Syntheses and behaviour activity of conjugated polyenic pheromone components
This thesis deals with the synthesis of conjugated dienicand trienic pheromone components- C12-C16alcohols, acetates and aldehydes and theirapplications in pheromone communication studies. Insect pheromones are widely used in modern pest management.The development of effective tools for plant protection is aresult of complex broad, interdisciplinary basic and appliedresearch. A practical use of pheromones for pest managementusually requires that specific active chemicals must beisolated,identified and produced synthetically. The creationof pheromone materials besides requires the identification ofthe active components, determination of the roles of otherpossible isomers or degradation products, the design ofdispensers of suitable substrates and evaporationparameters. The aim of the thesiswas critically to survey methods for the syntheses ofconjugated polyenic compounds and to focus to the synthesis ofseveral conjugated polyenic pheromone components providingsufficient quantities of chemically and isomerically purecompounds for bioassaying. The principal objective of the thesiswas concerned withthe further aim of developing effective synthetic materials forplant protection. The work was focussed: =>To identify the compoundscollected from the leafminer mothPhyllonorycter emberizaepenella(Lepidoptera:Gracillaridae) and perform a detailed identification of thepheromones of the Brazilian apple leafrollerBonagota cranaodes(Meyrick) (Lepidoptera: Tortricidae)and of the codling mothCydia pomonella(L.) (Lepidoptera: Tortricidae). =>Tostudy the effect of non-pheromonal isomers of the mainpheromone component on the sex attraction of B. cranaodes andC.pomonellain wind tunnel and field tests.=>To study the role of identified pheromonecomponents in the pheromone communication of the currant shootborer Lampronia capitella (Cl.) (Lepidoptera: Prodoxidae), andto design and optimize the dispenser for effective trapping.=>To investigate the presence of sex pheromonecomponents in the tobacco hawk mothManduca sexta(L.) (Lepidoptera: Sphingidae). The syntheses of four geometrical isomers of3,5-dodecadienyl acetate; (10E,12E,14Z)- and(10E,12E,14E)-(10,12,14)-hexadecatrien-1-als;(E,Z)-, (Z,E)-,and (Z,Z)-8,10-dodecadienol, codlemone acetate and aldehyde;(9Z,11Z)-9,11-tetradecadienol, corresponding acetate andaldehyde; all geometrical isomers of 8,10-and10,12-tetradecadienols and corresponding acetates wereperformed to ensure all these bioassays with syntheticpheromone components. All compounds were made in high chemicaland stereochemical purity, most of them more than 99%isomerically pure or by using several separation andpurification techniques. The suitable synthetic schemes for the synthesis of all fourgeometrical isomers of four conjugated dienic pheromonecomponents are presented in this thesis. The reactions and purification methods used here exemplifythe wide range of possibilities realized for such syntheses:they present the successful application of many syntheticmethods. The importance of this synthetic work is that thecompounds synthesized are not commercially available or on theother hand the purity of the purchasable compounds is notsatisfactory for research in the field of chemical ecology. Key words:Lepidoptera, sex pheromone, pheromonedispenser, 3,5-dodecadienyl acetate, 10,12,14-hexadecatrienal,8,10-dodecadienol, codlemone atsetate, codlemone aldehyde,8,10- tetradecadienol, 8,10-tetradecadienyl acetate,10,12-tetradecadienol, 10,12-tetradecadienyl acetate,Lampronia capitella, Manduca sexta, Bonagota cranaodes,Cydia pomonella, Phyllonorycter emberizaepenella,conjugated polyenic pheromone, conjugated diene, MPLC,(9Z,11Z)-9,11-tetradecadien-1-ol,(9Z,11Z)-9,11-tetradecadien-1-a
Synthesis and characterization of the four geometrical isomers of 3,5-dodecadienyl acetate
Practical convergent syntheses of the four geometrical isomers of 3,5-dodecadienyl acetate are presented. These substances have been characterized by NMR and mass spectroscopy. (3E,5Z)-3,5-Dodecadienyl acetate is the main female sex pheromone component of the leaf roller Bonagota cranaodes, which is an important insect pest in apples in South America. The isomeric 3,5-dodecadienyl acetates, as pure isomers and in defined mixtures, have been used as trap lures for Eying insects in field screening experiments in Lithuania. Although no insects were found in the control traps, the numbers of males caught in the baited traps were not high enough to be statistically significant
Sex pheromone communication of tentiform leaf-miners Phyllonorycter insignitella and Ph. nigrescentella from two related species groups
- …