Quantitative measurement of reproductive output in the American oyster, Crassostrea virginica (Gmelin), using an enzyme-linked immunosorbent assay (ELISA)

Abstract. A quantitative gonadal index was developed for oysters, Crassostrea virginica (Gmelin. 1791), using polyclonal antibodies from eggs and sperm. Percoll used in the purification of oyster eggs and sperm greatly improved the purity of antigens compared to filtering the egg or sperm through a fine mesh only. The antigen-antibody reaction was tested with indirect sandwich ELISA using alkaline phosphatase-conjugated goat anti-rabbit igG as a secondary antibody. Rabbit anti-oyster egg IgG and anti-oyster sperm IgG initially exhibited a weak cross-reactivity over somatic tissue. Absoring with acetone-dried oyster tissue powder removed this cross-reactivity. Both antisera exhibited strong specific immunological reactions to oyster eggs or sperm respectively. The quantity of eggs or sperm was measured using ELISA and a quantitative gonadosomatic index (dry wt of egg or sperm/dry wt oyster) (GSI) calculated. GSI from ELISA correlated with gonadal stage measured histologically. Monthly mean GSI of female oysters was highest during late spring to early summer (0·157–0·201) and lowest during early winter to early spring (0·002-0·000). Maximum GSI observed during the study was 0·422 for female oysters and 0·446 for male oysters. Female oysters produce 3·7–65·4 million eggs, with an average of 21·1 million during each spawning. A positive correlation was observed between the number of eggs produced and oyster size; the number of eggs in the gonad increased as oyster size (i.e. total dry wt) increased (r= 0·67); however, the relationship was non-linear. Large oysters contained proportionally fewer eggs. Prevalence of Perkinsus marinus parasitism was high, 90–100%, during the study, as was weighted incidence, 1·33 to 2·67, No statistically significant correlation was observed between infection intensity and the per cent weight of oyster eggs or egg number.     

Antibody responses after vaccination against equine influenza in the Republic of Korea in 2013

In this study, antibody responses after equine influenza vaccination were investigated among 1,098 horses in Korea using the hemagglutination inhibition (HI) assay. The equine influenza viruses, A/equine/South Africa/4/03 (H3N8) and A/equine/Wildeshausen/1/08 (H3N8), were used as antigens in the HI assay. The mean seropositive rates were 91.7% (geometric mean antibody levels (GMT), 56.8) and 93.6% (GMT, 105.2) for A/equine/South Africa/4/03 and A/equine/Wildeshausen/1/08, respectively. Yearlings and two-year-olds in training exhibited lower positive rates (68.1% (GMT, 14) and 61.7% (GMT, 11.9), respectively, with different antigens) than average. Horses two years old or younger may require more attention in vaccination against equine influenza according to the vaccination regime, because they could be a target of the equine influenza virus.     

Immunological study of an attenuated Salmonella Typhimurium expressing ApxIA,ApxIIA, ApxIIIA and OmpA of Actinobacillus pleuropneumoniae in a mouse model

Salmonella Typhimurium strain expressing the Actinobacillus pleuropneumoniae antigens, ApxIA, ApxIIA, ApxIIIA and OmpA, was previously constructed as a vaccine candidate for porcine pleuropneumonia. This strain was a live attenuated (∆lon∆cpxR∆asd)Salmonella as a delivery host and contained a vector containing asd. An immunological study of lymphocyte proliferation, T-lymphocyte subsets and cytokines in the splenocytes of a mouse model was carried out after stimulation with the candidate Salmonella Typhimurium by intranasal inoculation. The splenic lymphocyte proliferation and the levels of IL-4, IL-6 and IL-12 of the inoculated mice were significantly increased, and the T- and B-cell populations were also elevated. Collectively, the candidate may efficiently induce the Th1- and Th2-type immune responses.     

Optimal placement of the region of interest for bolus tracking on brain computed tomography angiography in Beagle dogs

This study aimed to determine the optimal placement of the region of interest (ROI) among four anatomical sites—pulmonary artery (PA), pulmonary vein (PV), aortic arch (AA), and carotid artery (CA)—in computed tomography (CT) brain angiography with automatic bolus tracking in healthy beagle dogs. Six beagles were included, and CT brain angiography was performed four times for each dog, to cover each ROI. The scan parameters, amount, and injection rate of the contrast medium were the same. The major intracranial arteries were selected for quantitative and qualitative evaluation: caudal cerebellar artery (CcA), basilar artery (BA), rostral cerebellar artery (RcA), caudal cerebral artery (CCA), middle cerebral artery (MCA), and rostral cerebral artery (RCA). Quantitative evaluation showed significantly higher CT attenuation values for the RcA, CCA, and MCA in the PA group and RcA and MCA in the PV group than in the CA group. Qualitative analysis revealed significantly higher scores for the BA, CCA, and MCA in the PA and PV groups than in the CA group. Venous contamination did not differ significantly among the ROIs, but the mean scores of the AA and CA groups were higher than those of the PA and PV groups. CT brain angiography using bolus tracking in the beagle dogs showed that the ROI should be placed at the PA or PV rather than at the CA for optimal images with strong contrast enhancement of the BA, RcA, CCA, and MCA and minimal venous contamination.     

A rapid molecular method for diagnosing epidemic dermatophytosis in a racehorse facility

Reasons for performing study: Identification of the species and strain of dermatophyte can play an effective role in control of disease outbreaks by establishing the source of infection. Current methods of identification are based on cultural and microscopic methods, often involving weeks before a positive identification are made. A rapid molecular diagnostic method would therefore be an important laboratory technique, but requires confirmation in equine clinical practice. Objectives: To test the sensitivity and specificity of molecular diagnostic methods applied to a racehorse herd from the Korean Racehorse Authority (KRA). Methods: A total of 57 DNA samples were collected from hairs and crusts of skin lesions in KRA racehorses with histories and clinical signs suggestive of dermatophytosis, which was confirmed by dermatophyte‐specific PCR amplification analysis using the primer pair for the chitin synthase 1 (CHS1) gene. Results: Thirty‐eight racehorses were definitively diagnosed with dermatophytosis using molecular and traditional diagnostic methods. PCR fingerprinting profiles using simple repetitive (GACA)₄ primers showed that all diagnosed horses had the same pattern profile. Oligonucleotide sequencing of CHS1 gene PCR products confirmed Trichophyton mentagrophytes as the infectious agent. Conclusions: This study demonstrates that the PCR‐based molecular diagnostic method is sensitive and specific and offers fast precise diagnosis of dermatophytosis in horses.     

叶片表皮指纹在杜鹃花属分类中的意义

本实验于2004年在东北林业大学进行。用指甲油印记法在光学显微镜下观察了杜鹃花属6个种(牛皮杜鹃 Rh.aureaum,兴安杜鹃Rh. dauricum, 照白杜鹃Rh. micranthum,迎红杜鹃Rh. mucronulatum,苞叶杜鹃 Rh. Redowskianum 和大字杜鹃Rh. schlippenbachii)的表皮指纹特征。对叶片的形态特征包括叶片下表皮气孔类型、保卫细胞和副卫细胞的特征、叶片两面的普通细胞(形状和垂周壁特征)和表皮毛进行了较详细的描述。所研究的6种杜鹃花中,有3种气孔类型,其中兴安杜鹃、照白杜鹃、和迎红杜鹃为单细胞型气孔(Pericytic 型),苞叶杜鹃为不规则型气孔(Anomocytic 型),牛皮杜鹃和大字杜鹃是平轴式气孔(Diacytic 式)。不同种间,单细胞型和平轴式气孔的副卫细胞类型在形状和表面特征上有所不同。普通表皮细胞的表面观为从四边形、六边形, 多边形或不规则型, 垂周壁呈平直或弯曲状。兴安杜鹃、照白杜鹃和迎红杜鹃3种的叶片两面均有腺鳞。所有这些叶片特点表明上述6种杜鹃花的表皮指纹具有种的特性。图4表2参29。     

Comparison of the bovine blood gas parameters produced with three types of portable blood gas analyzers

BackgroundA definite diagnosis should be made in the bovine practice field, however, it was difficult to perform laboratory analysis immediately. Currently, three types of portable blood gas analyzers are available in Korea.ObjectivesThis study aimed to evaluate the correlations among these three analyzers.MethodsSeventy-two plasma samples from Holstein-Friesian cows were used for blood gas analysis, and three instruments (EDAN i15 Vet, VETSCAN i-STAT, and EPOC) were operated simultaneously. Moreover, plasma calcium levels were compared between these portable analyzers and blood chemistry device, which is usually used in a laboratory environment. Pearson analysis was performed to confirm the correlation of each parameter produced with the three instruments and blood chemistry analyzer.ResultsAs results, high correlation was observed in parameters of pH, pO₂, potassium ion, ionized calcium, and glucose (p < 0.001, r > 0.7). In addition, pCO₂ showed a moderate correlation among the three analyzers (p < 0.001, r > 0.5), and there was no correlation among all instruments for sodium ions. There was also a high correlation between ionized calcium from the three portable devices and total calcium from the biochemistry analyzer (p < 0.001, r > 0.9).ConclusionsIn conclusion, there was a high correlation between results from the three different blood gas analyzers used in the bovine clinical field in Korea. Thus, a consistent diagnosis can be made even with different equipment if the operator is aware of the strengths and weaknesses of each piece of equipment and operates it properly.