Mechanism of Action and Therapeutic Potential of the β-Hairpin Antimicrobial Peptide Capitellacin from the Marine Polychaeta Capitella teleta     

Victoria N. Safronova  Pavel V. Panteleev  Stanislav V. Sukhanov  Ilia Y. Toropygin  Ilia A. Bolosov  Tatiana V. Ovchinnikova 《Marine drugs》2022,20(3)

Among the most potent and proteolytically resistant antimicrobial peptides (AMPs) of animal origin are molecules forming a β-hairpin structure stabilized by disulfide bonds. In this study, we investigated the mechanism of action and therapeutic potential of the β-hairpin AMP from the marine polychaeta Capitella teleta, named capitellacin. The peptide exhibits a low cytotoxicity toward mammalian cells and a pronounced activity against a wide range of bacterial pathogens including multi-resistant bacteria, but the mechanism of its antibacterial action is still obscure. In view of this, we obtained analogs of capitellacin and tachyplesin-inspired chimeric variants to identify amino acid residues important for biological activities. A low hydrophobicity of the β-turn region in capitellacin determines its modest membranotropic activity and slow membrane permeabilization. Electrochemical measurements in planar lipid bilayers mimicking the E. coli membrane were consistent with the detergent-like mechanism of action rather than with binding to a specific molecular target in the cell. The peptide did not induce bacterial resistance after a 21-day selection experiment, which also pointed at a membranotropic mechanism of action. We also found that capitellacin can both prevent E. coli biofilm formation and destroy preformed mature biofilms. The marked antibacterial and antibiofilm activity of capitellacin along with its moderate adverse effects on mammalian cells make this peptide a promising scaffold for the development of drugs for the treatment of chronic E. coli infections, in particular those caused by the formation of biofilms.  相似文献   

The effects of timber harvest in a South Carolina blackwater bottomland     

Donna Perison  Joseph Phelps  Christina Pavel  Robert Kellison 《Forest Ecology and Management》1997,90(2-3):171-185

This study was initiated on the South Fork Edisto River in South Carolina to investigate and compare the impacts of two different harvest methods (helicopter and rubber-tired skidder) on the ecological structure and function of a blackwater forested wetland. The two harvest treatments were chosen to represent a broad spectrum of potential impacts and were compared to an undisturbed site. Following harvest in 1991, functional responses in vegetative productivity, herpetofaunal populations, and soil and water quality were evaluated in 1992 and 1993. Herbaceous biomass was greater on the helicopter and skidder treatments than on the undisturbed control. In general, the biomass measured on the skidder treatment was not significantly different from the biomass measured on the helicopter treatment. Higher decomposition rates were noted in the harvested areas as compared to the control. This was mainly attributed to higher soil temperatures, which accelerated microbial activity. Increased decomposition rates may have been responsible for elevated levels of ammonium and organic carbon observed in ground water samples. A total of 29 species of herpetofauna (10 amphibians and 19 reptiles) were observed during the study. Salamanders were found more often in the undisturbed control. Reptiles were observed more frequently in the harvested area. Although herpetofaunal species composition was different between harvest and control, indices of diversity were similar.  相似文献   

Effects of different crating periods on selected biochemical indices in broiler chickens     

Chloupek P  Vecerek V  Voslarova E  Bedanova I  Suchy P  Pistekova V  Kozak A 《Berliner und Münchener tier?rztliche Wochenschrift》2008,121(3-4):132-136

Effects of different crating periods on selected biochemical indices were monitored in a group of unsexed ROSS 308 broiler chickens aged 42 days. 120 randomly selected chickens were weighted and placed in 15 heavy duty plastic crates with reduction in floor space approx. 160 cm2/kg of body weight of broilers (average body weight was 2.75 kg). Five crates were kept for 4 hours (Group 4h), another five crates for 8 hours (Group 8 h) and another five crates for 12 hours (Group 12h). After tested periods of crating the broilers were released and blood samples were withdrawn from Vena bosilico in 24 randomly selected birds from each group (Groups 4 h, 8 h, 12 h respectively) and also in other 24 randomly selected non-crated control birds. The results of our experiment proved that duration of crating significantly influenced the stress response in broiler chickens. The duration of crating period was positively correlated with the plasma corticosterone level and negatively correlated with the lactate dehydrogenase, cholesterol, triglycerides, glucose and lactate levels in the blood of broiler chickens.  相似文献   

POSITRON EMISSION TOMOGRAPHY OF THE EQUINE DISTAL LIMB: EXPLORATORY STUDY          下载免费PDF全文

Mathieu Spriet  Pablo Espinosa  Andre Z. Kyme  Pavel Stepanov  Val Zavarzin  Stephen Schaeffer  Scott A. Katzman  Larry D. Galuppo  David Beylin 《Veterinary radiology & ultrasound》2016,57(6):630-638

Positron emission tomography (PET) is a highly sensitive, noninvasive imaging technique for quantifying biological functions of tissues. However, at the time of this study, PET imaging applications had not been reported in the horse. The aim of this exploratory study was to determine whether a portable high‐resolution PET scanner could be used to image the equine distal limb. Images of the front feet and fetlocks of three research horses, with known lesions localized to the distal front limbs, were acquired under general anesthesia after administration of ¹⁸F‐fluorodeoxyglucose (¹⁸F‐FDG), with doses ranging from 1.5 to 2.9 MBq/kg. The radiation exposure measured during imaging was slightly higher than ^99mTechnetium scintigraphy. However, the use of general anesthesia allowed the proximity and the contact time with the patient to be minimized for the staff involved. ¹⁸F‐FDG uptake was evident throughout the soft tissues, with the highest uptake in the coronary band and the lowest uptake in the tendons. Anatomic structures could be discriminated due to the high contrast between soft tissue and bone. Detected lesions included lysis of the flexor cortex of the navicular bone, lesions of flexor tendons and suspensory ligament, and abnormal uptake through the lamina of a laminitic subject. Findings indicated that tomographic molecular imaging is feasible in the equine distal limb and could be useful as a future diagnostic technique for clinical and research studies, especially those involving tendinopathy/desmopathy and laminitis.  相似文献   

Tear production,intraocular pressure and conjunctival bacterial flora in selected captive wild ruminants          下载免费PDF全文

Pavel Kvapil  Tina Pirš  Brigita Slavec  Roman Luštrik  Tadej Zemljič  Eva Bártová  Bojana Stranjac  Marjan Kastelic 《Veterinary ophthalmology》2018,21(1):52-57

  相似文献   

Circle of life: the common hamster (Cricetus cricetus) adaptations to the urban environment     

Alexey V. SUROV  Elena A. ZAYTSEVA  Alexandr V. KUPTSOV  Elena A. KATZMAN  Pavel L. BOGOMOLOV  Alexandra S. SAYAN  Ekaterina V. POTASHNIKOVA  Nikolay N. TOVPINETZ  Ekaterina V. KUZNETSOVA  Alexey Y. TSELLARIUS  Natalia Y. FEOKTISTOVA 《Integrative zoology》2019,14(4):383-395

Traditionally, urbanization has been seen as a negative phenomenon for biota. However, changes in the environmental parameters induced by urbanization might be favorable for some species. Over the past half‐century, the common hamster has actively populated cities, establishing populations in some European, Russian and Kazakhstan cities. Based on integrative methods, we investigated free‐range common hamsters inhabiting Simferopol from 2015 to 2018 to reveal possible adaptations to the urbanized environment across several parameters, including lifespan, hibernation period, reproductive activity and body mass. Results show that in urban areas, the common hamster demonstrates an extremely short hibernation period compared to other localities, possibly due to enhanced food resources from urban forestry (walnuts, locus and hazelnut), allowing the species to start breeding very early (February) and finish as late as October. We present the first evidence of polyandry for this species: mating of receptive females with several males and subsequent confirmation of multiple paternity. Despite high reproductive potential, the lifespan of the common hamster in urban conditions is generally very short (less than 1 year). We speculate that in the process of synurbization, the common hamster's innate plasticity across many life history traits permits it to successfully colonize throughout a wide range of habitats, with the ability to form novel adaptations to urban environments.  相似文献   

Detecting the non-breeding region and migration route of Whimbrels(Numenius phaeopus rogachevae)in the East Asian-Australasian Flyway     

Fenliang Kuang  Wei Wu  David Li  Chris J.Hassell  Grace Maglio  Kar-Sin K.Leung  Jonathan T.Coleman  Chuyu Cheng  Pavel S.Tomkovich  Zhijun Ma 《中国鸟类》2022,(1):72-77

Determining the migration routes and connections of migratory birds at the population level helps clarify intraspecific differences in migration.Five subspecies...  相似文献   

Chalcone synthase expression and pigments deposition in wheat with purple and blue colored caryopsis     

Václav Trojan  Milena Musilová  Tomáš Vyhnánek  Bořivoj Klejdus  Pavel Hanáček  Ladislav Havel 《Journal of Cereal Science》2014

Red and white caryopses are typical in common wheat. Genotypes with purple and blue caryopses are also described. This coloring is caused by anthocyanins which deposit in the pericarp (purple) or aleurone layer (blue). The anthocyanins biosynthetic pathway is well described. The key enzyme is chalcone synthase (CHS). It catalyzes the first step. We observed the deposition of anthocyanins in the pericarp and aleurone layer, the expression of a chalcone synthase gene and the amount of two anthocyanins - cyanidin-3-glycoside (pericarp of purple caryopses), and delphinidin-3-glycoside (aleurone layer of blue caryopses) during caryopsis development. Purple pigment deposition was not homogeneous and/or uniform. At first, small isolated spots of purple color were formed and thereafter they expanded. In blue caryopses, however, the coloring process was more homogeneous. The expression of chalcone synthase mRNA occurred five days before pigment deposition and finished earlier than expected. Amounts of cyanidin-3-glycoside and delphinidin-3-glycoside increased in a similar manner. Amounts of these fell at the end of caryopses development probably due to formation of more complex substances.  相似文献   

Newly identified host range of viruses infecting species of the genus Allium and their distribution in six habitats in the Czech Republic     

Faten Mansouri  František Krahulec  Martin Duchoslav  Pavel Ryšánek 《Plant pathology》2021,70(6):1496-1507

  相似文献   

Free radical scavenging activity of different extracts and some constituents from the leaves of Ligustrum vulgare and L. delavayanum     

Nagy M  Spilková J  Vrchovská V  Kontseková Z  Sersen F  Mucaji P  Grancai D 《Fitoterapia》2006,77(5):395-397

The free radical scavenging activity of the water infusions, different organic solvent extracts and some constituents from Ligustrum vulgare and Ligustrum delavayanum leaves was assessed with the aid of DPPH radical. Among the samples screened, water infusions had the strongest free radical scavenging capacity. From the tested compounds scavenging active flavonoid aglycones are present in the most active chloroform fractions from both leaves samples.  相似文献