Monoclonal antibodies to equine IgM improve the sensitivity of West Nile virus-specific IgM detection in horses

West Nile virus (WNV) is a zoonotic pathogen of global importance. In horses with neurological signs, detection of WNV-specific immunoglobulin M (IgM) in serum is widely used to identify clinical cases of WNV encephalitis. Here, we describe the development of two monoclonal antibodies (mAbs) to equine IgM which were used in a WNV IgM-specific enzyme-linked immunosorbent assay (ELISA). Their performance was compared to an established assay based on polyclonal anti-IgM. Check test serum samples from the National Veterinary Service Laboratory (NVSL) were used to evaluate the performance of the three anti-IgM antibodies. The anti-IgM 1-22 mAb correctly identified all NVSL samples. Both the polyclonal antibody and monoclonal anti-IgM 2B-63 identified eight out of ten samples correctly. The three assays were then compared using serum samples from clinically healthy animals (n=33) and horses with neurological signs (n=21). High Spearman rank correlations (0.76-0.86) were found among the ELISA results. Inter-test agreements (weighted kappa) for assay interpretation resulted in strong agreement (0.95) of the results obtained by the mAbs and moderate agreements when monoclonal and polyclonal anti-IgM-based assays were compared. To determine the analytical sensitivities of anti-WNV IgM detection, serial dilutions of WNV IgM-positive serum samples were analyzed. The highest sensitivity was obtained by using the anti-IgM 1-22 mAb to capture IgM from equine serum. In conclusion, the use of monoclonal anti-IgM antibodies can improve the sensitivity of IgM detection in the acute phase of WN disease.     

Experimental Pyelonephritis in Dogs

Both E. coli and S. aureus were simultaneously injected into the left renal arteries of 55 female dogs. The arteries were occluded for 10 minutes prior to the injection and 10 minutes after. The renal veins were occluded during the injection and for 10 minutes after.

Ten animals did not survive longer than 24 hours. Ten of 45 developed neither renal lesions nor bacteriuria; of the remaining 35 which did, five were killed on each of the second, seventh and fourteenth days, and their renal lesions were assessed. Eighteen of the remaining 2 which developed bacteriuria were killed 3 to 12 weeks following surgery when bacteria could no longer be recovered from the urine. Only two dogs had persistent bacteriuria 12 weeks after surgery. All animals which developed bacteriuria had gross lesions in the left kidney but not the right.

Naturally occurring renal lesions were found in 17 of 78 random-source dogs at laparotomy. E. coli was cultured from the urine of five of these dogs but not from the kidneys. These lesions were morphologically similar to experimental ones.

It is concluded that with this method renal lesions similar to spontaneous ones can be produced, but care must be taken to exclude the relatively large percentage of random-source dogs with naturally occurring lesions from any study.

Various forms of infectious nephritis have been reported to be among the commonest diseases of dogs (1, 2). The successful production of chronic pyelonephritis in dogs depends on a variety of factors in addition to injecting bacteria into either the renal artery or ureter. Thus, ureteral obstruction, renal anoxia and reduced pulse pressure increased the susceptibility to renal infection (3, 4, 6, 7, 8).

Our laboratory has been concerned with the production of experimental pyelonephritis in dogs so that the efficacy of various treatments could be studied. The present work was undertaken to standardize methods of producing the disease and to compare experimental renal lesions with naturally occurring ones.

     

Genome‐Wide Association Study for Sperm Concentration in Holstein‐Friesian Bulls

The aim of the study was to screen the entire bull genome to identify markers and candidate genes underlying sperm concentration. The analysed data set originates from a population of 877 Polish Holstein‐Friesian bulls. Based on sperm concentration value, two extreme groups of bulls were created: Low (L, n = 126) and High (H, n = 140). Each bull was genotyped using the Illumina BovineSNP50 BeadChip. Genome‐wide association analysis was performed with the use of GoldenHelix SVS7 software. An additive model with a Cohran–Armitage test, Correlation/Trend adjusted by a Bonferroni test, was used to estimate the effect of SNP marker for sperm concentration. Thirteen markers reached genome‐wide significance. The most significant SNPs were located on chromosome 3 (rs109154964 and rs108965556), 14 (rs41621145) and 18 (rs41615539), in the close vicinity of protein arginine methyltransferase 6 (PRMT6), Sel1 repeat containing 1 (SELRC1), triple QxxK/R motif containing (TRIQK) and zinc finger homeobox 3 (ZFHX3) genes, respectively. For three other candidate genes located close to significant markers (within a distance of ca 1 Mb), namely histone deacetylase 9 (HDAC9), an inhibitor of DNA binding 2 (ID2) and glutathione S‐transferase theta 1 (GSTT1), their potential role in the production of male germ cells was confirmed in earlier studies. Six additional candidate genes (Vav3, GSTM1, CDK5, NOS3, PDP1 and GAL3ST1) were suspected of being significantly associated with sperm concentration or semen biochemistry. Our results indicate the genetic complexity of sperm concentration but also open the possibility for finding causal polymorphism useful in marker‐assisted selection.     

Use of Cholesterol‐Loaded Cyclodextrin in Donkey Semen Cryopreservation Improves Sperm Viability but Results in Low Fertility in Mares

The use of cholesterol‐loaded cyclodextrin (CLC) on semen cryopreservation has been related with better sperm viability in several species; however, the effect on fertility is not known in donkey semen. Ejaculates (n = 25) from five donkeys were diluted in S‐MEDIUM with 0, 1, 2 or 3 mg of CLC/120 × 10⁶ spermatozoa. Semen was frozen, and thawed samples were evaluated by computer‐assisted sperm analyser system (CASA), supravital test, hyposmotic swelling test and fluorescent dyes to assess the integrity of sperm membranes. Mares (n = 60) were inseminated with frozen‐thawed semen treated with the doses of 0 or 1 mg CLC. Percentages of sperm with progressive motility and with functional plasma membrane were greater (p < 0.05) in the CLC‐treated groups than in the control. Percentages of intact plasma membrane and intact plasma membrane and acrosome detected by fluorescent dyes were also greater (p < 0.05) in CLC‐treated groups. Although no difference (p > 0.05) in conception rates was detected between groups (control, 3/30, 10%; CLC‐treated, 1/30, 3.3%), fertility was low for artificial insemination programs in mares. Therefore, we firstly demonstrated that frozen semen treated with CLC in S‐MEDIA extender before freezing improves the in vitro sperm viability, but semen treated or not with CLC in S‐MEDIUM extender results in a very low conception rate in mares inseminated with thawed donkey semen.     

A "Schrodinger Cat" Superposition State of an Atom

A "Schrodinger cat"-like state of matter was generated at the single atom level. A trapped 9Be+ ion was laser-cooled to the zero-point energy and then prepared in a superposition of spatially separated coherent harmonic oscillator states. This state was created by application of a sequence of laser pulses, which entangles internal (electronic) and external (motional) states of the ion. The Schrodinger cat superposition was verified by detection of the quantum mechanical interference between the localized wave packets. This mesoscopic system may provide insight into the fuzzy boundary between the classical and quantum worlds by allowing controlled studies of quantum measurement and quantum decoherence.     

Apollo 12 seismic signal: indication of a deep layer of powder

The seismic signal caused by the Apollo 12 lunar module is interpreted in terms of propagation between source and receiver through a layer of powder in which sound velocity increases with depth. This increase, which is due to compaction, extends over several kilometers and leads to a concentration of seismic waves toward the surface. Computer simulations with the use of ray acoustics and on the assumption of a randomly undulating lunar surface approximate well the observed signal. Seismic amplitudes are greatly enhanced in such a medium compared to solid rock, so that the observed signal requires less power to be transmitted than previously estimated.     

Mercury's magnetosphere after MESSENGER's first flyby

Observations by MESSENGER show that Mercury's magnetosphere is immersed in a comet-like cloud of planetary ions. The most abundant, Na+, is broadly distributed but exhibits flux maxima in the magnetosheath, where the local plasma flow speed is high, and near the spacecraft's closest approach, where atmospheric density should peak. The magnetic field showed reconnection signatures in the form of flux transfer events, azimuthal rotations consistent with Kelvin-Helmholtz waves along the magnetopause, and extensive ultralow-frequency wave activity. Two outbound current sheet boundaries were observed, across which the magnetic field decreased in a manner suggestive of a double magnetopause. The separation of these current layers, comparable to the gyro-radius of a Na+ pickup ion entering the magnetosphere after being accelerated in the magnetosheath, may indicate a planetary ion boundary layer.