A Bacterial Effector Mimics a Host HSP90 Client to Undermine Immunity.

The molecular chaperone HSP90 facilitates the folding of several client proteins, including innate immune receptors and protein kinases. HSP90 is an essential component of plant and animal immunity, yet pathogenic strategies that directly target the chaperone have not been described. Here, we identify the HopBF1 family of bacterial effectors as eukaryotic-specific HSP90 protein kinases. HopBF1 adopts a minimal protein kinase fold that is recognized by HSP90 as a host client. As a result, HopBF1 phosphorylates HSP90 to completely inhibit the chaperone's ATPase activity. We demonstrate that phosphorylation of HSP90 prevents activation of immune receptors that trigger the hypersensitive response in plants. Consequently, HopBF1-dependent phosphorylation of HSP90 is sufficient to induce severe disease symptoms in plants infected with the bacterial pathogen, Pseudomonas syringae. Collectively, our results uncover a family of bacterial effector kinases with toxin-like properties and reveal a previously unrecognized betrayal mechanism by which bacterial pathogens modulate host immunity.

PssJ Is a Terminal Galactosyltransferase Involved in the Assembly of the Exopolysaccharide Subunit in Rhizobium Leguminosarum bv. Trifolii.

Rhizobium leguminosarum bv. trifolii produces exopolysaccharide (EPS) composed of glucose, glucuronic acid, and galactose residues at a molar ratio 5:2:1. A majority of genes involved in the synthesis, modification, and export of exopolysaccharide are located in the chromosomal Pss-I region. In the present study, a ΔpssJ deletion mutant was constructed and shown to produce EPS lacking terminal galactose in the side chain of the octasaccharide subunit. The lack of galactose did not block EPS subunit translocation and polymerization. The in trans delivery of the pssJ gene restored the production of galactose-containing exopolysaccharide. The mutant was compromised in several physiological traits, e.g., motility and biofilm production. An impact of the pssJ mutation and changed EPS structure on the symbiotic performance was observed as improper signaling at the stage of molecular recognition, leading to formation of a significant number of non-infected empty nodules. Terminal galactosyltransferase PssJ was shown to display a structure typical for the GT-A class of glycosyltransferases and interact with other GTs and Wzx/Wzy system proteins. The latter, together with PssJ presence in soluble and membrane protein fractions indicated that the protein plays its role at the inner membrane interface and as a component of a larger complex.

Magnetic resonance imaging of liver tumors using gadoxetic acid (Gd-EOB-DTPA) - pilot study.

BACKGROUND: Magnetic resonance imaging using gadoxetic acid, a hepatocyte-specific contrast agent, is one of the most useful MRI techniques used to diagnose liver tumours in humans. During the hepato-biliary phase, there is uptake of gadoxetic acid by normal hepatocytes, leading to hepatic parenchymal enhancement. This feature is used in human medicine to diagnose hepatic parenchymal metastatic disease, to differentiate primary liver tumours, to diagnose liver cirrhosis and focal nodular hyperplasia. This study presents the preliminary results of magnetic resonance imaging of focal lesions localised in the liver parenchyma in dogs following the administration of gadoxetic acid. RESULTS: The lesion enhancement ratio (ERlesion) in the tumour metastasis was 0.05; the liver enhancement ratio (ERliver) - 0.49 and the post-contrast lesion-to-liver contrast ratio (CR) was 0.17. In dogs with hepatocellular hyperplasia, these values were 0.54; 0.51; and 1.18, respectively. In two dogs with a hepatic adenoma, the ERlesion was 0.26 and 0.17, respectively; the ERliver was 0.47 and 0.47, respectively and the CR was 0.33 and 0.31, respectively. In the dog with a neuroendocrine tumour, the ERlesion was 0.03; the ERliver amounted to 0.58 and the CR was 0.35. In the case of a hepatocellular carcinoma, these coefficients were 0.2, 0.6 and 0.3, respectively. CONCLUSION: Based on the results, it may be assumed that the MR images of the proliferative hepatic parenchymal lesions in dogs using gadoxetic acid are similar to those obtained in humans. This suggests that the contrast enhancement patterns used in human medicine may be useful in differentiating hepatic parenchymal lesions in dogs.

Impact of Abiotic and Biotic Environmental Conditions on the Development and Infectivity of Entomopathogenic Nematodes in Agricultural Soils.

Many organisms, including beneficial entomopathogenic nematodes (EPNs), are commonly found in the soil environment. EPNs are used as biopesticides for pest control. They have many positive characteristics and are able to survive at sites of application for a long time, producing new generations of individuals. The occurrence of populations depends on many environmental parameters, such as temperature, moisture, soil texture, and pH. Extreme temperatures result in a decrease in the survival rate and infectivity of EPNs. Both high humidity and acidic soil pH reduce populations and disrupt the biological activity of EPNs. Nematodes are also exposed to anthropogenic agents, such as heavy metals, oil, gasoline, and even essential oils. These limit their ability to move in the soil, thereby reducing their chances of successfully finding a host. Commonly used fertilizers and chemical pesticides are also a challenge. They reduce the pathogenicity of EPNs and negatively affect their reproduction, which reduces the population size. Biotic factors also influence nematode biology. Fungi and competition limit the reproduction and survival of EPNs in the soil. Host availability enables survival and affects infectivity. Knowledge of the influence of environmental factors on the biology of EPNs will allow more effective use of the insecticidal capacity of these organisms.

Computed Tomographic Findings of Dental Disease and Secondary Diseases of the Head Area in Client-Owned Domestic Rabbits (Oryctolagus cuniculus): 90 Cases.

Domestic rabbits have teeth that grow throughout the animal's life and are prone to disease. Clinical signs of dental disease in domestic rabbits are non-specific, and, therefore, a definitive diagnosis usually requires additional methods. This study was carried out on a group of 105 domestic rabbits aged 3 to 9 years. In total, 90 domestic rabbits with dental disease visible on CT images and other secondary diseases of the head area qualified for this study. Malocclusion was found in 57 (63.3%). Retrograde elongation of the tooth apices in the mandible was present in 39 (43.3%), and it was present in the maxilla in 48 (53%). Clinical tooth crowns were overgrown in 39 (43%). Dental abscesses were present in 54 (63%). Secondary to the presence of a dental abscess, osteomyelitis was found in 43 (79% of the animals with a dental abscess). Dental inflammatory resorption was found in 36 (40%). Secondary to dental disease, nasal cavity inflammation was found in 18 (20%). Otitis media was present in six (6.7%). The most common dental disease found in this study's animals was malocclusion secondary to abnormal clinical crown abrasion and abnormal tooth growth. In domestic rabbits, osteomyelitis is a common complication of dental abscesses. Computed tomography is an invaluable diagnostic method in the diagnosis of dental disease and secondary diseases of the head area, such as inflammation of the nasal cavities or otitis media, in pet rabbits.

Laparoscopic ureteroneocystostomy in the treatment of urinary incontinence due to ectopy of the ureters in female dogs: A pilot study.

Ureteral ectopia is rare and requires surgical treatment after a thorough diagnostic workup. Open surgical techniques for repositioning ectopic ureters have been known for many years and are well described in the literature. However, to the best of our knowledge, no laparoscopic method of correcting this pathology has been described, which, in our opinion, would benefit the animal in terms of the healing process and overall clinical outcomes. This study aimed to evaluate the possibility of laparoscopic treatment of ureteral ectopia, which causes urinary incontinence in dogs. All of the operated ten dogs presented in this study were client-owned females with symptoms of urinary incontinence due to a unilateral intramural ectopic ureter. A three-trocar laparoscopic technique was used to perform the ureteroneocystostomy of the ectopic ureter. In this article, clinicopathological data, imaging features, procedural findings, complications, and short- and long-term outcomes are presented. The procedure was feasible in all cases. No major postoperative complications were observed. Among the minor complications, slight hematuria was observed in three dogs, which resolved spontaneously. In the period of at least one year after surgery, no negative impact of the procedure was observed. Seven of the ten operated dogs regained urinary continence. The remaining three dogs required additional surgery (urethral bulking) because of a lack of improvement after adjuvant pharmacological treatment. Overall, good-to-excellent long-term outcomes can be achieved; however, dogs that remain incontinent after laparoscopic ureteroneocystostomy may require additional treatment.

The effect of changes in cardiovascular activity on corneal biomechanics and pulsation in rabbits.

The aim was to assess the relationships between cardiovascular activity, corneal pulse characteristics, and corneal biomechanics in rabbits. Seventeen rabbits were randomly assigned to one of two anesthetic regimens to induce differences in arterial blood pressure and heart rate. Experimental protocol included measuring blood flow parameters in the ophthalmic artery by color Doppler imaging, corneal biomechanical parameters using a non-contact tonometer Corvis ST, and the corneal pulse (CP) signal using a non-contact ultrasonic technique. Statistically significantly lower mean values of normalized amplitudes of higher CP harmonics and changes in eight of the twelve corneal biomechanical parameters were observed in the rabbit group with lower arterial blood pressure and higher heart rate, intraocular pressure, and resistive index. The results of partial correlations showed that the CP signal energy and amplitude of its first harmonic correlate with the resistive index, diastolic and mean arterial pressures, whereas no statistically significant correlation was found between any of the CP parameters and intraocular pressure. Our pilot study indicates, for the first time, that non-contact and continuous measuring of corneal pulse allows indirectly assessing changes in cardiovascular activity when the confounding effect of intraocular pressure is eliminated.

Laparoscopic assisted percutaneous herniorrhapy in dogs using PIRS technique.

BACKGROUND: In the literature, no studies describe the use of laparoscopic techniques for inguinal hernia repair in canine clinical patients. The surgical technique-Percutaneous Internal Ring Suturing (PIRS) presented in this article is the world's first minimally invasive laparoscopic surgical technique for inguinal canal closure in dogs. AIM: The aim of the presented study is to evaluate the possibility of employment of the laparoscopic PIRS technique in clinical practice as well as to technically evaluate its usefulness in the treatment of the inguinal hernia in dogs. The presented study describes the procedure and the results of laparoscopic treatment of 11 inguinal hernias in nine dogs (two bilateral). METHODS: The whole procedure is performed under camera control introduced through one umbilical trocar. The very closure of the inner inguinal ring is done with the injection needle by a small puncture over the inguinal canal with the help of which the suture material is inserted, and the canal of the operated inguinal hernia is closed. Each operated dog underwent a thorough clinical examination before surgery which was combined with ultrasound examination of the inguinal canals before, immediately after and three months after surgery. RESULTS: There was no hernia recurrence in the study period in the operated dogs and all individuals returned to full mobility immediately after recovery from anesthesia. CONCLUSIONS: Due to the low invasiveness and simplicity of performance, the PIRS technique described in the study should be taken into account when choosing a treatment method for non-traumatic inguinal hernia in dogs. At the same time, the possibility of using the described technique in other types of inguinal hernia in dogs requires further research.

A liver core needle biopsy technique in guinea pigs (Cavia porcellus).

The aim of this study was to describe a core needle biopsy technique in the guinea pig (Cavia porcellus) and to assess the incidence of complications when applying this method. Biopsies were taken from the right hepatic lobe of 36 healthy guinea pigs under ultrasound guidance using a Tru-Cut needle. There were no immediate complications in 35 animals but ultrasound images showed a haemorrhage from the biopsy site in one guinea pig. The haemorrhage stopped after administering a sterile cooling dressing. One guinea pig died 13 days after the biopsy due to late complications. The procedure is in some animals associated with severe, potential life-threatening, complications. Assessment of the biopsy site by ultrasonography for 30 min after the procedure is recommended to allow timely handling of haemorrhage. The procedure is not recommended in animals with a suspected coagulopathy. Due to the risk of severe complications, this procedure should be restricted to guinea pigs where the result of the biopsy examination is expected to be valuable for the choice of treatment or prognosis. Owners should be made aware of the risks associated with the procedure.

Thermodynamic and kinetic supercooling of liquid in a wedge pore.

Cyclohexane allowed to capillary condense from vapor in an annular wedge pore of mica in a surface force apparatus (SFA) remains liquid down to at least 14 K below the bulk melting-point T(m). This is an example of supercooling of a liquid due to confinement, like melting-point depression in porous media. In the wedge pore, however, the supercooled liquid is in equilibrium with vapor, and the amount of liquid (and thereby the radius of curvature r of the liquid-vapor interface) depends on the surface tension gamma(LV) of the liquid, not the interfacial tension between the solid and liquid. At coexistence r is inversely proportional to the temperature depression DeltaT below T(m), in accordance with a recently proposed model [P. Barber, T. Asakawa, and H. K. Christenson, J. Phys. Chem. C 111, 2141 (2007)]. We have now extended this model to include effects due to the temperature dependence of both the surface tension and the enthalpy of melting. The predictions of the improved model have been quantitatively verified in experiments using both a Mark IV SFA and an extended surface force apparatus (eSFA). The three-layer interferometer formed by the two opposing, backsilvered mica surfaces in a SFA was analyzed by conventional means (Mark IV) and by fast spectral correlation of up to 40 fringes (eSFA). We discuss the absence of freezing in the outermost region of the wedge pore down to 14 K below T(m) and attribute it to nonequilibrium (kinetic) supercooling, whereas the inner region of the condensate is thermodynamically supercooled.

A Case of Two Sisters Suffering from 46,XY Gonadal Dysgenesis and Carrying a Mutation of a Novel Candidate Sex-Determining Gene STARD8 on the X Chromosome.

Identification of novel genes involved in sexual development is crucial for understanding disorders of sex development (DSD). Here, we propose a member of the START domain family, the X chromosome STARD8, as a DSD candidate gene. We have identified a missense mutation of this gene in 2 sisters with 46,XY gonadal dysgenesis, inherited from their heterozygous mother. Gonadal tissue of one of the sisters contained Leydig cells overloaded with cholesterol droplets, i.e., structures previously identified in 46,XY DSD patients carrying mutations in the STAR gene encoding another START domain family member, which is crucial for steroidogenesis. Based on the phenotypes of our patients, we propose a dual role of STARD8 in sexual development, namely in testes determination and testosterone synthesis. However, further studies are needed to confirm the involvement of STARD8 in sexual development.

Solid phase synthesis of functionalised SAM-forming alkanethiol-oligoethyleneglycols.

We present an efficient solid phase synthesis methodology that provides easy access to a range of functionalised long-chain alkanethiol-oligoethyleneglycols that form well-defined self-assembled monolayers on gold and are compatible with pre- or post-assembly conjugation of (bio)molecules. We demonstrate the versatility of our synthetic route by synthesising LCAT-OEGs with a range of functional moieties, including peptides, electro-active redox groups, chemical handles for post-assembly conjugation of (bio)molecules, and demonstrate the application of our LCAT-OEG monolayers in immunosensing, where they show good biocompatibility with minimal biofouling.

Capillary condensation of water between mica surfaces above and below zero-effect of surface ions.

We have studied the capillary condensation of water from saturated vapor below 0 degrees C in the annular wedge-pore formed around two mica surfaces in contact in a surface force apparatus. The condensed water remains liquid down to at least -9 degrees C, and the measured condensate size is close to the predictions of a recent model for the dependence of the interfacial curvature of supercooled capillary condensates on temperature and surface tension. The small deviation observed may be accounted for by assuming that solute as K(2)CO(3) from the mica-condensate interface dissolves in the condensates and gives rise to an additional depression of the freezing point apart from that caused by the interface curvature. By contrast, measurements of the interface curvature at relative vapor pressures of 0.95-0.99 at 20 degrees C confirm a significantly larger deviation from the Kelvin equation. The magnitude of the deviation is in remarkable agreement with that calculated from the results of an earlier study of capillary condensation of water from a nonpolar liquid, also at T = 20 degrees C. Evidently, additional solute from the surrounding mica surface migrates into the condensates at room temperature. We conclude that the surface diffusion of ions on mica is much slower at subzero temperatures than at room temperature.