Sex-specific association of urate and levodopa-induced dyskinesia in Parkinson's disease

BACKGROUND AND PURPOSE

As a major antioxidant, uric acid (UA) is known to be associated with the clinical progression of Parkinson's disease (PD). This study investigated whether baseline UA levels are associated with the risk for levodopa-induced dyskinesia (LID) in PD in a sex-dependent manner.

METHODS

In all, 152 patients with de novo PD (78 males and 74 females) who were followed up for >2 years were enrolled. The effect of baseline serum UA levels on LID-free survival was assessed by Cox regression, separately for sex, whilst being adjusted for potential confounding factors. The optimal UA level cut-off value to determine the high-risk group for LID was set using Contal and O'Quigley's method.

RESULTS

Levodopa-induced dyskinesia developed in 23 (29.5%) male patients and 30 (40.5%) female patients. Cox regression showed a significant interaction between UA level and sex. Higher UA levels were associated with a higher risk for LID in male PD patients (hazard ratio 1.380; 95% confidence interval 1.038-1.835; P = 0.027), although this relationship was not observed in female PD patients. The optimal UA level cut-off for LID in male PD was 7.2 mg/dl, and the high UA group had a 5.7-fold higher risk of developing LID than the low UA group.

CONCLUSIONS

Contrary to a presumptive beneficial role of UA, the present study demonstrated that higher UA levels are associated with increased risk of LID occurrence in male patients with PD, suggesting a sex-dependent role of UA in LID.

Cognitive anosognosia is associated with frontal dysfunction and lower depression in Parkinson's disease

BACKGROUND AND PURPOSE

Anosognosia refers to a deficit of self-awareness or impaired insight for cognitive and behavioral problems. Cognitive anosognosia was explored in de novo patients with Parkinson's disease (PD) and its relationship to cognitive function and neuropsychiatric symptoms was investigated.

METHODS

The cross-sectional study enrolled 340 drug-naïve patients with PD. According to the presence of mild cognitive impairment (MCI) and subjective cognitive complaint, patients were classified as patients with cognitive anosognosia (PD-CA, n = 74), with normal cognitive recognition (PD-NR, n = 184) or with cognitive underestimation (PD-CU, n = 82). After controlling for covariates, cognitive performance and neuropsychiatric symptoms were compared between the PD groups.

RESULTS

Cognitive anosognosia was found in 21.8% of patients with de novo PD. The PD-CA group showed poorer performance in all cognitive domains except for attention. Amongst PD patients with MCI, those with cognitive anosognosia showed lower composite z-scores in the Stroop color reading test than those without. The Beck Depression Inventory score in the PD-NR group was lower than that in the PD-CU group and higher than that in the PD-CA group. The Cognitive Complaints Interview score mediated the association between cognitive anosognosia and Beck Depression Inventory score.

CONCLUSIONS

Cognitive anosognosia in PD was associated with greater frontal dysfunction and lower depression. Since cognitive anosognosia has a harmful impact on PD patients and their caregivers due to overestimation of their abilities in everyday life, early identification of cognitive anosognosia in PD is important in management and prognosis.

Effects of Alzheimer's disease and Lewy body disease on subcortical atrophy

BACKGROUND AND PURPOSE

Subcortical structures are affected by neurodegeneration in Alzheimer's disease (AD) and Lewy body disease (LBD). Although the co-occurrence of AD and LBD pathologies and their possible interaction have been reported, the effect of AD and LBD on subcortical structures remains unknown. The effects of AD and LBD on subcortical atrophy and their relationship with cognitive dysfunction were investigated.

METHODS

The cross-sectional study recruited 42 patients with pure AD related cognitive impairment (ADCI), 30 patients with pure LBD related cognitive impairment (LBCI), 58 patients with mixed ADCI and LBCI, and 29 normal subjects. A general linear model was used to compare subcortical volume and shape amongst the groups, to investigate the independent and interaction effects of ADCI and LBCI on subcortical shape and volume, and to analyze the relationship between subcortical volume and cognitive dysfunction in each group.

RESULTS

Alzheimer's disease related cognitive impairment and LBCI were independently associated with subcortical atrophies in the hippocampus and amygdala and in the hippocampus and putamen respectively, but their interaction effect was not significant. Compared to the control group, the pure LBCI group exhibited additional local atrophies in the amygdala, caudate and thalamus. Subcortical atrophies correlated differently with cognitive dysfunction according to the underlying causes of cognitive dysfunction.

CONCLUSIONS

The patterns of subcortical atrophies and their correlation with cognitive dysfunction differ according to the underlying AD, LBD or concomitant AD and LBD.

Clinical relevance of amnestic versus non-amnestic mild cognitive impairment subtyping in Parkinson's disease

BACKGROUND AND PURPOSE

To clarify whether subtyping of amnestic and non-amnestic mild cognitive impairment (MCI) is clinically relevant in Parkinson's disease (PD) by analyzing patterns of neuroimaging and longitudinal cognitive changes.

METHODS

We performed comparative analyses of cortical thickness, hippocampal volume, white matter integrity and resting-state functional connectivity between the patients with de-novo PD with amnestic MCI (PD-aMCI) (n = 50) and non-amnestic MCI (PD-naMCI) (n = 50) subtypes. Additionally, we assessed the longitudinal rate of cognitive decline in each cognitive domain over time and the rate of dementia conversion in patients with de-novo PD-aMCI (n = 125) and PD-naMCI (n = 61).

RESULTS

The demographic data showed that scores in memory domains were lower in the PD-aMCI group compared with the PD-naMCI group. There were no significant differences in cortical thickness, hippocampal volume and white matter integrity between the two groups, although the PD-aMCI group exhibited more cortical thinning and hippocampal atrophy relative to the control group. The PD-aMCI group exhibited increased functional connectivity in the left posterior parietal region with the salience network relative to the PD-naMCI group. The longitudinal cognitive assessment demonstrated that patients with PD-aMCI exhibited a more rapid cognitive decline in frontal/executive function than those with PD-naMCI (P = 0.022). In addition, the PD-aMCI group had a higher risk of dementia conversion than the PD-naMCI group.

CONCLUSIONS

This study suggests that the designation of PD-MCI subtypes based on memory function would highlight the heterogeneity of functional correlates as well as the longitudinal cognitive prognosis.

Hydro-nanofibrous mesh deep cell penetration: a strategy based on peeling of electrospun coaxial nanofibers

A two-step strategy for coaxial electrospinning and postelectrospinning is an effective method for fabricating superfine nanofibers composed of highly swellable hydrogels. Alginate and poly(ε-caprolactone) [PCL] were coelectrospun via fibrous meshes with a coaxial nozzle; alginate at the core was subsequently cross-linked in calcium chloride solution. The PCL sheath was removed from the meshes by repeated organic-phase washing. The peeling process was monitored by scanning electron microscopy, transmission electron microscopy, and differential scanning calorimetry, and the complete removal of the PCL outer layers was confirmed by the thinning of the fiber volume. The obtained alginate hydronanofiber showed extreme water-swellability and mass erosion depending on the degree of cross-linking. We also measured the nanoscale and macroscale mechanical properties of a single nanofiber and of the whole mesh by atomic force microscopy and rheometry. Quantitative analysis of nanomechanical properties indicated that the hydronanofiber with higher cross-linking density had higher stiffness and Derjaguin-Müller-Toporov modulus. Cells laid on the mesh and the vertical infiltration distance were visualized and quantified by confocal laser scanning microscopy. Cells on the mesh with higher cross-linking density infiltrated deeply to the bottom of the mesh. Thus, hydrogel-like nanofibrous meshes are versatile matrices allowing for deep infiltration of cells throughout the mesh via manipulation of the mechanical properties of the nanofiber.

Epizootiological characteristics of viable bacteria and fungi in indoor air from porcine, chicken, or bovine husbandry confinement buildings

Microorganisms found in bioaerosols from animal confinement buildings not only foster the risk of spreading diseases among livestock buildings, but also pose health hazards to farm workers and nearby residents. This study identified the various microorganisms present in the air of swine, chicken, and cattle farms with different kinds of ventilation conditions in Korea. Microbial air samples were collected onto Petri dishes with bacterial or fungal growth media using a cascade impactor. Endotoxin levels in total dust were determined by the limulus amebocyte lysate kinetic QCL method. Prevalent Gram-positive bacteria were Staphylococcus (S.) lentus, S. chromogenes, Bacillus (B.) cereus, B. licheniformis, and Enterococcus faecalis, while the dominant fungi and Gram-negative bacteria were Candida albicans and Sphingomonas paucimobilis, respectively. Considering no significant relationship between the indoor dust endotoxin levels and the isolation of Gram-negative bacteria from the indoor air, monitoring the indoor airborne endotoxin level was found to be also critical for risk assessment on health for animals or workers. The present study confirms the importance of microbiological monitoring and control on animal husbandry indoor air to ensure animal and worker welfare.

Nasal immunization with mannan-decorated mucoadhesive HPMCP microspheres containing ApxIIA toxin induces protective immunity against challenge infection with Actinobacillus pleuropneumoiae in mice

The development of subunit mucosal vaccines requires an appropriate delivery system or an immune modulator such as an adjuvant to improve antigen immunogenicity. The nasal route for vaccine delivery by microparticles has attracted considerable interest, although challenges such as the rapid mucociliary clearance in the respiratory mucosa and the low immunogenicity of subunit vaccine still remain. Here, we aimed to develop mannan-decorated mucoadhesive thiolated hydroxypropylmethyl cellulose phthalate (HPMCP) microspheres (Man-THM) that contain ApxIIA subunit vaccine - an exotoxin fragment as a candidate for a subunit nasal vaccine against Actinobacillus pleuropneumoniae. For adjuvant activity, mucoadhesive thiolated HPMCP microspheres decorated with mannan could be targeted to the PRRs (pathogen recognition receptors) and mannose receptors (MR) of antigen presenting cells (APCs) in the respiratory immune system. The potential adjuvant ability of Man-THM for intranasal immunization was confirmed by in vitro and in vivo experiments. In a mechanistic study using APCs in vitro, it was found that Man-THM enhanced receptor-mediated endocytosis by stimulating the MR of APCs. In vivo, the nasal vaccination of ApxIIA-loaded Man-THM in mice resulted in higher levels of mucosal sIgA and serum IgG than mice in the ApxIIA and ApxIIA-loaded THM groups due to the specific recognition of the mannan in the Man-THM by the MRs of the APCs. Moreover, ApxIIA-containing Man-THM protected immunized mice when challenged with strains of A. pleuropneumoniae serotype 5. These results suggest that mucoadhesive Man-THM may be a promising candidate for a nasal vaccine delivery system to elicit systemic and mucosal immunity that can protect from pathogenic bacteria infection.

Hepatitis E virus as an emerging zoonotic pathogen

Hepatitis E outbreaks are a serious public health concern in developing countries. The disease causes acute infections, primarily in young adults. The mortality rate is approximately 2%; however, it can exceed 20% in pregnant women in some regions in India. The causative agent, hepatitis E virus (HEV), has been isolated from several animal species, including pigs. HEV genotypes 3 and 4 have been isolated from both humans and animals, and are recognized as zoonotic pathogens. Seroprevalence studies in animals and humans indirectly suggest that HEV infections occur worldwide. The virus is primarily transmitted to humans via undercooked animal meats in developed countries. Moreover, transfusion- and transplantation-mediated HEV infections have recently been reported. This review summarizes the general characteristics of hepatitis E, HEV infection status in animals and humans, the zoonotic transmission modes of HEV, and HEV vaccine development status.

Differential diagnosis of Brucella abortus by real-time PCR based on a single-nucleotide polymorphisms

To diagnose brucellosis effectively, many genus- and species-specific detection methods based on PCR have been developed. With conventional PCR assays, real-time PCR techniques have been developed as rapid diagnostic tools. Among them, real-time PCR using hybridization probe (hybprobe) has been recommended for bacteria with high DNA homology among species, with which it is possible to make an accurate diagnosis by means of an amplification curve and melting peak analysis. A hybprobe for B. abortus was designed from a specific single-nucleotide polymorphism (SNP) on the fbaA gene. This probe only showed specific amplification of B. abortus from approximately the 14th cycle, given a melting peak at 69°C. The sensitivity of real-time PCR was revealed to be 20 fg/µl by 10-fold DNA dilution, and the detection limit was 4 CFU in clinical samples. This real-time PCR showed greater sensitivity than that of conventional PCR and previous real-time PCR based on Taqman probe. Therefore, this new real-time PCR assay could be helpful for differentiating B. abortus infection with rapidity and accuracy.

Serological surveillance studies confirm the Rift Valley fever virus free status in South Korea

Rift Valley fever is a mosquito-borne zoonotic disease of domestic ruminants. This disease causes abortions in pregnant animals, and it has a high mortality rate in newborn animals. Recently, a Rift Valley fever virus (RVFV) outbreak in the Arabian Peninsula increased its potential spread to new regions worldwide. In non-endemic or disease-free countries, early detection and surveillance are important for preventing the introduction of RVFV. In this study, a serological surveillance was conducted to detect antibodies against RVFV. A total of 2382 serum samples from goats and cattle were randomly collected from nine areas in South Korea from 2011 to 2013. These samples were tested for antibodies against RVFV, using commercial ELISA kits. None of the goats and cattle were positive for antibodies against RVFV. This finding suggests that this disease is not present in South Korea, and furthermore presents the evidence of the RVFV-free status of this country.

Bone marrow-derived clonal mesenchymal stem cells inhibit ovalbumin-induced atopic dermatitis

Mesenchymal stem cells (MSCs) possess immunomodulatory activities, including suppression of T- and B-cell activation. However, their effects on atopic dermatitis (AD) have not yet been studied. Using an ovalbumin-induced AD mouse model, we investigated whether MSCs can be used as therapeutics in AD. We isolated both allogeneic and syngeneic clonal MSCs (cMSCs) from mouse bone marrow according to the subfractionation culturing method. Our cMSCs suppressed both T- and B-cell activation. T-cell proliferation and cytokine production, including interferon (IFN)-γ and interleukin (IL)-4, were suppressed by inhibition of transcription factors, such as T-bet, GATA-3, and c-Maf. Those transcription factors were nitric oxide dependent. Immunoglobulin E (IgE) suppression occurred through downregulation of AID and BLIMP-1, important regulators for isotype class switch and B-cell differentiation. The cMSCs were injected intravenously into ovalbumin-induced AD mouse model, and the therapeutic effects were analyzed. Injection of both allogeneic and syngeneic cMSCs in an AD mouse model inhibited cell infiltration in skin lesions and decreased the serum level of IgE. IL-4 expression was also suppressed by cMSCs in both the lymph node and skin. The cMSCs migrated to skin lesions and draining lymph nodes. Taken together, these data demonstrated that cMSCs, which suppressed T- and B-cell functions, can be used for the treatment of AD in mice.

Guidelines for vaccination of dogs and cats in Korea

This guideline contains the recommended vaccination schedules of dogs and cats from World Small Animal Veterinary Association (WSAVA) and American Animal Hospital Association (AAHA). In 2010, WSAVA published guidelines for the vaccination of dogs and cats. And, in 2011, AAHA also published guidelines for vaccination of dogs. In Korea, there is no published guideline for vaccination of dogs and cats yet. Therefore, the plane of vaccination also reports the present situation of vaccination schedule of dogs and cats in Korean animal hospitals.

Competitive ELISA for the detection of antibodies to Rift Valley fever virus in goats and cattle

Rift Valley fever virus (RVFV) is one of the important emerging viral diseases of serious impact in public health and animal hygiene both in human and animal industries. In this study, we developed a monoclonal antibody-based competitive ELISA for the detection of antibodies to RVFV in goats and cattle. The recombinant N protein of RVFV was expressed in E. coli with a six-histidine tag, and the purified N protein was used for detecting antigen with a competitive monoclonal antibody against RVFV antibodies. The competitive ELISA (C-ELISA) could detect antibodies at 9-11 days after inoculation in goats and cattle with a sensitivity of 94.7% (virus neutralization titer >32) and specificity of 99.7%, respectively. In addition, the C-ELISA did not show any cross-reactivity with positive sera against arboviruses such as Akabane, Aino, Chuzan, Ibaraki and bovine ephemeral fever virus, which are prevalent viral agents in ruminant animals throughout Southeast Asia. The results of the present study indicate that the C-ELISA is a simple, rapid and convenient serodiagnostic method for RVFV in goats and cattle.

Mucoadhesive and pH-sensitive thiolated Eudragit microspheres for oral delivery of Pasteurella multocida antigens containing dermonecrotoxin

In this study, cysteine was conjugated to the Eudragit to have mucoadhesive and pH-sensitive properties. Pasteurella multocida dermonecrotoxin (PMT) is a major virulence factor as a causative agent of atrophic rhinitis (AR) in swine and, therefore, inactivated P. multocida was used as a candidate vaccine in the current study. PMT-loaded thiolated Eudragit microspheres (TEMS) prepared using W/O/W emulsion-solvent evaporation method were characterized to assess their efficacy in oral vaccination. PMT-loaded TEMS were observed as spherical shapes with smooth surfaces and average particle sizes were 5.2 +/- 0.55 microm. The loading efficiency of PMT in the TEMS was about 75.3%. A significantly higher percentage of PMT from PMT-loaded TEMS was released at pH 7.4 than at pH 1.5. Murine macrophage stimulated with PMT-loaded TEMS facilitated a gradual secretion of tumor necrosis factor-alpha and nitric oxide as immune stimulatory mediators in a time dependent manner, suggesting that the released PMT from PMT-loaded TEMS had immune stimulating activity of AR vaccine in vitro.

The development of a selective medium for the Brucella abortus strains and its comparison with the currently recommended and used medium

The Brucella spp. are fastidious and relatively slow-growing organisms. The isolation of such strains in a variety of specimens often requires the use of a selective medium to reduce or eliminate the growth of unexpected microorganisms. The modified Brucella selective (MBS) medium, which contains improved antibiotic mixtures, erythritol as the only carbon source, and neutral red as a pH indicator, showed good selectivity for the Brucella abortus strains, including the RB51 vaccine strain. Erythritol in the MBS medium was able to promote and/or recover the delayed growth of the B. abortus strains through the antibiotic mixtures. The Brucella colonies, which assumed a pinkish color at their central part, were easily differentiated from other organisms. The MBS medium also allows the isolation of the Brucella strains even in contaminated specimens and/or in specimens containing small numbers of viable organisms. Moreover, this medium can be applied to environmental samples for the isolation of the Brucella strains, and it can thus offer epidemiologic traceback sources for the dissemination or transfer of diseases. Therefore, the MBS medium can be applied as a useful tool of important control measures in the eradication programs.

Comparative study of gamma interferon production in mice immunized with outer membrane proteins and whole bacteria of Brucella abortus

Brucella abortus is the intracellular bacterium that causes bovine brucellosis and a chronic human disease known as undulant fever. Interferon (IFN)-gamma plays critical roles in defending against intracellular bacterial infection. In this experiment, we demonstrated the difference in IFN-gamma production between the splenocytes of mice inoculated with outer membrane proteins (OMPs) of B. abortus and whole live bacteria. Our results showed that the OMP-inoculated group showed more IFN-gamma production than did the bacteria-infected group, suggesting that OMPs are candidates for the induction of immune response.

Application and evaluation of the MLVA typing assay for the Brucella abortus strains isolated in Korea

BACKGROUND

A Brucella eradication program has been executed in Korea. To effectively prevent and control brucellosis, a molecular method for genetic identification and epidemiological trace-back must be established. As part of that, the MLVA typing assay was evaluated and applied to B. abortus isolates for analyzing the characteristics of the regional distribution and relationships of foreign isolates.

RESULTS

A total of 177 isolates originating from 105 cattle farms for the period 1996 to 2008 were selected as representatives for the nine provinces of South Korea. A dendrogram of strain relatedness was constructed in accordance with the number of tandem repeat units for 17 loci so that it was possible to trace back in the restricted areas. Even in a farm contaminated by one source, however, the Brucella isolates showed an increase or decrease in one TRs copy number at some loci with high DI values. Moreover, those 17 loci was confirmed in stability via in-vitro and in-vivo passage, and found to be sufficiently stable markers that can readily identify the inoculated strain even if minor changes were detected. In the parsimony analysis with foreign Brucella isolates, domestic isolates were clustered distinctively, and located near the Central and Southern American isolates.

CONCLUSION

The MLVA assay has enough discrimination power in the Brucella species level and can be utilized as a tool for the epidemiological trace-back of the B. abortus isolates. But it is important to consider that Brucella isolates may be capable of undergoing minor changes at some loci in the course of infection or in accordance with the changes of the host.

Determination of fecal shedding rates and genotypes of swine hepatitis E virus (HEV) in Korea

Hepatitis E virus (HEV) infection induces an acute hepatitis or a subclinical disease in humans. It is known that HEV is a zoonotic agent and pigs are major reservoirs of HEV. This study was conducted to determine the fecal shedding rates of HEV in various age groups of pigs and identify the genotypes of swine HEV prevailing in Korea. A total of 565 fecal samples were collected from suckling piglets, post-weaning pigs, growing pigs, and sows at 12 swine farms. RT-PCR was used to detect the presence of swine HEV in the feces. Every swine farm examined in this study had HEV-infected pigs. The fecal shedding rates of the swine HEV at individual farms were in the range of 2.1-35.4%. The overall fecal shedding rate of HEV in individual pigs was 17.5%. The HEV shedding rates of suckling piglets, post-weaning pigs, growing pigs and sows in their feces were 6.3, 16.3, 38.0 and 9.3%, respectively. When the genotypes of swine HEVs identified in this study were determined, they were all grouped into genotype 3. They were further subdivided into subtype 3a together with human and swine HEVs isolated in the U.S.A.

Reproduction of fowl typhoid by respiratory challenge with Salmonella Gallinarum

Fowl typhoid is a disease of adult chickens and is caused by Salmonella Gallinarum infection via the alimentary tract. The experimental reproduction of fowl typhoid per os (PO) requires artificial conditions to minimize the effect of gastric acid, and several Salmonella serovars have been known to be transmitted via the respiratory route. Therefore, we have hypothesized the existence of a respiratory route for Salmonella Gallinarum infection and have attempted to reproduce fowl typhoid via intratracheal challenge. In accordance with our hypothesis, the intratracheal challenges of Salmonella Gallinarum reproduced exactly same lesions as fowl typhoid and induced higher mortality and morbidity than those of the PO challenge. Therefore, this study represents the first reproduction of fowl typhoid via respiratory route, and our findings may be useful for understanding the transmission of Salmonella Gallinarum in the field.

Prognostic indicators of gastric carcinoma confined to the muscularis propria

AIMS

Gastric carcinoma confined to the muscularis propria (MPGC) is considered an intermediate-stage carcinoma. A method of discriminating between more favourable and less favourable prognostic groups of this entity is critically needed in dealing with this heterogeneous disease. The aim of this study was to examine the correlation between survival of patients with MPGC and its various clinicopathological parameters.

METHODS AND RESULTS

Various clinicopathological parameters were studied in 171 tissue samples including: macroscopic appearance, size, age, sex, stage, invasion depth, Lauren and Ming classifications, extent, lymphatic emboli and nodal metastasis. Tumours macroscopically resembling early gastric cancers, younger patient age, absence of lymphatic tumour emboli and lower stage were significantly associated with better prognosis of MPGC by univariate analysis. Tumours macroscopically resembling early gastric cancers, younger patient age and Lauren's diffuse type were significantly associated with a better prognosis of MPGC by multivariate analysis.

CONCLUSIONS

These indicators are practical parameters for predicting patient prognosis in clinical practice. The description of these parameters should be carefully noted in the final report and pathologists should evaluate the macroscopic appearance of MPGC.

Pyelonephritis associated with Staphylococcus intermedius in a Siberian tiger (Panthera tigris altaica)

Pyelonephritis, in which Staphylococcus intermedius was isolated, was diagnosed in a 4-year-old female Siberian tiger (Panthera tigris altaica). At necropsy, the renal pelvis was dilated with a large amount of purulent exudates. Microscopically, the lesions of renal pelvis and medulla consisted of necrotic foci intermingled primarily with numerous degenerative neutrophils and a few lymphocytes, plasma cells and macrophages. Bacteriology showed the presence of S. intermedius. This is the first report on pyelonephritis associated with S. intermedius in wild felidae.

Induction of protective immune responses against the challenge of Actinobacillus pleuropneumoniae by the oral administration of transgenic tobacco plant expressing ApxIIA toxin from the bacteria

Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia. Among the virulence factors, ApxIIA, a bacterial exotoxin, is reportedly expressed in many serotypes and is considered as a candidate for the development of a vaccine against the bacterial infection. Previously, we isolated a field strain of A. pleuropneumoniae serotype 2 in Korea and characterized its exotoxins to develop an oral vaccine. In this study, we initially confirmed the immunogenicity of ApxIIA expressed in Escherichia coli. We then developed transgenic tobacco expressing ApxIIA and tested its efficacy to induce a protective immune response against A. pleuropneumoniae infection after oral administration of the plant powder. We observed that protective immune responses were induced in mice after oral administration of the plant powder once a week for 4 weeks. Immunoassays revealed that the levels of antigen-specific immunoglobulin G against ApxIIA increased in mice that were fed a powder made from the transgenic plant, but not in mice fed a powder made from wild-type tobacco. Additionally, mice fed the transgenic plant powder were protected from an injection of a lethal dose of A. pleuropneumoniae. These results support that the transgenic plant may be a suitable candidate for an oral vaccine that could be used effectively against A. pleuropneumoniae infection.

Molecular differentiation of common promoters in Salmonella class 1 integrons

The integron is a mobile gene element which harbors antibiotic-resistance gene cassettes capable of site-specific integration. Among the four known types of integrons, the class 1 integron has been associated with multidrug-resistance in pathogenic bacteria. These gene cassettes have been the focus of a series of studies. The gene cassettes share a common promoter, and their expression levels are affected not only by their proximity to the promoter, but also by the strength (weak, hybrid and strong) of the common promoter, P1, as well as the presence of the additional promoter, P2. In this study, we developed molecular methods for the differentiation of promoter structures using PCR, restriction enzyme analysis, and polyacrylamide gel electrophoresis, and have applied them to the characterization of class 1 integrons in 33 non-typhoidal Salmonella serotypes in Korea. Class 1 integrons were detected in four serotypes: S. Derby (SD), S. Istanbul (SI), S. Paratyphi B (SPB), and S. Livingstone (SL), and the amplicon sizes were 1.0 Kb (SD, SI and SPB) and 2.0 Kb (SL). All of the 1.0 kb amplicons harbored gene cassettes (aadA1 or aadA2), but the 2.0 kb amplicon harbored three (dhfrXII-orfF-aadA2) gene cassettes, which conferred streptomycin/spectinomycin (aadA) and trimethoprim (dhfr) resistances. Our promoter structure study revealed three types of promoters; strong P1 (SD), weak P1 (SPB and SL), and weak P1+P2 (SI). In conclusion, the class 1 integrons were detected in Korean NTS, and their promoter structures were found to be variable. Therefore, our methods may prove helpful in terms of our understanding of molecular diversity, as well as the transmission of class 1 integrons and phenotype-genotype relationships in antibiotic-resistance.

In vitro study of the immune stimulating activity of an athrophic rhinitis vaccine associated to chitosan microspheres

Chitosan microspheres (CMs) were prepared by an ionic gelation process with tripolyphosphate and characterized. Bordetella Bronchiseptica Dermonecrotoxin (BBD), a major virulence factor of a causative agent of atrophic rhinitis (AR), was loaded on to the CMs for nasal vaccination. BBD-loaded CMs were observed as aggregated shapes although unloaded CMs were observed as relatively spherical ones. The average particle size of the BBD-loaded CMs was 4.39 microm. The lower the molecular weight of chitosan and the higher the medium pH, the greater was the release of BBD from the BBD-loaded CMs in vitro due to weaker intermolecular interaction between chitosan and BBD. Tumor necrosis factor alpha and nitric oxide from RAW264.7 cells exposed to BBD-loaded CMs were gradually secreted with time, suggesting that released BBD from CMs had immune stimulating activity of AR vaccine in vitro.

Quantitative Analysis of Interleukin-6 Expression in Porcine Spleen Cells and Alveolar Macrophages using Real-Time PCR

Interleukin-6 (IL-6), a multifocal cytokine produced by lymphoid and non-lymphoid cells, regulates immune responses, acute-phase reactions against bacterial infections, and haematopoiesis. After cloning and sequencing of porcine IL-6, the expression pattern of porcine IL-6 mRNA was evaluated through real-time RT-PCR using porcine immune cells (spleen cells and alveolar macrophages) following stimulation with LPS. The sequence has been reported to GenBank with Accession no. AF 518322. The nucleotide sequence was different at the 89th and 205th positions in comparison with M80258, but only at the 205th with M86722. Comparison of porcine IL-6, Accession no. AF 518322, with IL-6 of human, canine, ovine, and mouse showed homologies of 78%, 81%, 82% and 73% in nucleotide sequence and 42%, 69%, 61% and 42% in amino acids. Expression of IL-6 mRNA was induced by stimulation with LPS. IL-6 mRNA expression in alveolar macrophages peaked at 2 h and decreased sharply to control levels at 4 h, whereas it peaked at 14 h and decreased at 24 h in spleen cells after stimulation with LPS (1 microg/ml). These results suggest that IL-6 mRNA expression in porcine immune cells is cell-type specific and the results of this study could be used as the basis for research on the porcine immune system.

Regulation of proinflammatory mediator production in RAW264.7 macrophage byVibrio vulnificus luxSandsmcR

Vibrio vulnificus causes fatal septicemia in human hosts, which is the consequence of raw shellfish consumption. The mortality following septicemia is dependent on the in vivo production of inflammatory mediators, including tumor necrosis factor-alpha (TNFalpha). The present study was set up to investigate the association of quorum sensing in V. vulnificus with the host immune response. The effect of quorum sensing on cytotoxicity and the production of proinflammatory mediators was examined using the murine macrophage cell-line RAW264.7. Cytotoxicity was determined by measuring lactate dehydrogenase release in the culture medium. Extracellular products from luxS- and smcR-deficient mutants exhibited weak cytotoxic effects on RAW264.7 cells. The production of the proinflammatory cytokines TNFalpha, IL-1beta and IL-6 was measured with real-time PCR and ELISA, and production was measured with Griess reagents. Mutation of both luxS and smcR delayed the transcription of TNFalpha, IL-1beta and IL-6 genes. Also, levels of both TNFalpha and nitric oxide induced by luxS- and smcR-deficient mutants were significantly lower than those induced by parent strains. These results suggest that quorum sensing could be involved in the modulation of TNFalpha and nitric oxide produced from host cells by regulating virulence factors, and that V. vulnificus facilitates its host's mortality and bacterial survival by enhancing virulence on host cells.

Comparative analysis on the 5'-untranslated region of bovine viral diarrhea virus isolated in Korea

Samples of 249 bovine abortuses, one intestine, and four diarrheal stools from 254 cows were collected, and bovine viral diarrhea virus (BVDV) was detected by reverse transcription-polymerase chain reaction (RT-PCR). Subsequently, virus isolation was preformed with PCR-positive samples, and then PCR product of 5^′-untranslated region (UTR) of BVDV isolate was sequenced and analyzed. Among the samples collected, 20 (from 17 bovine abortuses, one intestine, and two diarrheal stools) were positive for BVDV RT-PCR; four BVDVs (from two bovine abortuses, one intestine, and one diarrheal stool) were isolated. When the four isolates were biotyped in cell culture, one BVDV isolate from a bovine abortus was cytopathic and the others were non-cytopathic. In addition, three isolates were genotyped as BVDV-1 and one isolate from a diarrheal stool as BVDV-2. In phylogenetic analysis, it suggested that the BVDV-2 isolate in Korea is closer to the North American strains than Asian strains. This is the first report on the identification and isolation of BVDV-2 in Korea.

Controlled release ofBordetella bronchiseptica dermonecrotoxin (BBD) vaccine from BBD-loaded chitosan microspheresIn Vitro

Chitosan microspheres were prepared by ionic gelation process with sodium sulfate for nasal vaccine delivery. Bordetella Bronchiseptica Dermonecrotoxin (BBD) as a major virulence factor of a causative agent of atrophic rhinitis (AR) was loaded to the chitosan microspheres for vaccination. Morphology of BBD-loaded chitosan microspheres was observed as spherical shapes. The average particle sizes of the BBD-loaded chitosan microspheres were about 2.69 microm. More BBD was released with an increase of molecular weight of chitosan and with an increase of medium pH in vitro due to weaker intermolecular interaction between chitosan and BBD. Tumor necrosis factor-alpha (TNFalpha) and nitric oxide (NO) from RAW264.7 cells stimulated with BBD-loaded chitosan microspheres were gradually secreted, suggesting that released BBD from chitosan microspheres had immune stimulating activity of AR vaccine.

Stable transformation of rice (Oryza sativa L.) via microprojectile bombardment of highly regenerative, green tissues derived from mature seed

A highly efficient and reproducible transformation system for rice ( Oryza sativa L. cv. Taipei 309) was developed using microprojectile bombardment of highly regenerative, green tissues. These tissues were induced from mature seeds on NB-based medium containing 2,4-dichlorophenoxyacetic acid (2,4-D), 6-benzylaminopurine (BAP) and high concentrations of cupric sulfate under dim light conditions; germinating shoots and roots were completely removed. Highly regenerative, green tissues were proliferated on the same medium and used as transformation targets. From 431 explants bombarded with transgenes [i.e. a hygromycin phosphotransferase ( hpt) gene plus one of a wheat thioredoxin h ( wtrxh), a barley NADP-thioredoxin reductase ( bntr), a maize Mutator transposable element ( mudrB) or beta-glucuronidase ( uidA; gus) gene], 28 independent transgenic events were obtained after an 8- to 12-week selection period, giving a 6.5% transformation frequency. Of the 28 independent events, 17 (61%) were regenerable. Co-transformation of the second introduced transgene was detected in 81% of the transgenic lines tested. Stable integration and expression of the foreign genes in T(0) plants and T(1) progeny were confirmed by DNA hybridization, western blot analyses and germination tests.

The cerebrovascular response to traditional acupuncture after stroke

Acupuncture is useful in treating the nausea and vomiting related to chemotherapy, adult postoperative surgery pain and postoperative dental pain. We obtained single-photon emission computed tomography (SPECT) brain perfusion images of six patients with middle cerebral artery occlusion obtained before and after acupuncture and compared the changes in regional cerebral blood flow (rCBF) to those in normal control. Images were obtained before and after acupuncture at six traditional acupoints (LI 4, 10, 11, 15 and 16 and TE5) in the affected arm. The baseline image was subtracted from the postacupuncture image, to produce a subtraction image displaying only voxels with values >2 SD from the mean and those voxels were coregistered to the baseline SPECT or T2-weighted MRI. Similar images were obtained before and after acupuncture of eight normal volunteers. Statistical parametric mapping with a threshold of P =0.001 and a corrected P of 0.05 was performed for group comparison between postacupuncture and baseline SPECT. Focally increased CBF was seen in all patients especially in the hypoperfused zone surrounding the ischaemic lesion, the ipsilateral or contralateral sensorimotor area, or both. Normal subjects showed increased rCBF mainly in the parahippocampal gyrus, premotor area, frontal and temporal areas bilaterally and ipsilateral globus pallidus. Acupuncture stimulation after stroke patients appears to activate perilesional or use-dependent reorganised sites and might be a way of looking at brain reorganisation.

Clostridium perfringens type A Myonecrosis in a Horse in Korea

Acute hemorrhagic myonecrosis accompanied by severe inter- and intrafascicular edema and hemorrhage of the right gluteal area was diagnosed in a 13-year-old male thoroughbred horse. Once the muscular and fascicular changes were subsided, the horse then developed acute respiratory problem. Histologically, the lung had diffuse severe hemorrhage with mild neutrophilic infiltration. The cause of death was acute respiratory failure that is believed to occur secondary to toxaemic event. Alpha and beta2 toxin secreting Clostiridum perfringens type A was isolated from the muscle and lung. The diagnosis was based on the light microscopic examination, bacterial toxinotyping and toxin genotyping from the muscular and pulmonary lesion. Also, susceptibility of the isolates to antimicrobial agents was determined.

Expression of recombinant porcine interleukin-2 and application of its antibody to immunoassays

Interleukin-2 plays an important role in T lymphocyte proliferation and immune response regulations. In this study, porcine IL-2 cDNA was cloned from peripheral blood mononuclear cells, and recombinant porcine IL-2 (rpIL-2) was expressed in Escherichia coli. The size of rpIL-2 without signal peptides was about 15 kDa when determined by SDS-PAGE and Western blotting analysis. Anti-rpIL-2 antibody was produced from mice immunized with the purified rpIL-2, and its specificity was examined by Western blotting and ELISA. In the Western blotting assay, anti-rpIL-2 and anti-recombinant human IL-2 (rhIL-2) antibodies specifically recognized rpIL-2 and rhIL-2, respectively. However, anti-rpIL-2 antibody did not recognize rhIL-2, and anti-rhIL-2 antibody also did not react with rpIL-2 in the same assay. In ELISA, anti-rpIL-2 antibody strongly interacted with both rpIL-2 and rhIL-2, and anti-rhIL-2 antibody also efficiently recognized both proteins. Taken together, the specificity of anti-rpIL-2 antibody for rpIL-2 was demonstrated by Western blotting and ELISA. It was also shown that ELISA is more efficient than Western blotting in determining the species cross-reactivity of anti-rpIL-2 antibody.

Chitosan and D-glucosamine induce expression of Th1 cytokine genes in porcine spleen cells

Chitosan, a polymer of D-glucosamine, is a polysaccharide derived from the chitin found in the exoskeleton of shellfish, such as shrimp or crabs. The effects of chitosan has been recognized that chitosan-fed farm animals demonstrated higher weight gains but less incidence of diseases than the unfed ones. However, these beneficial effects has not been elucidated clearly. In this study, we examined the modulatory effect of chitosan and D-glucosamine on the expression of porcine cytokines in vitro. Porcine spleen cells were cultured in the presence of chitosan and D-glucosamine, and the effects of chitosan on the cytokine mRNA expression were evaluated. Expressions of IL-2 and IFN-gamma were increased in the chitosan-treated porcine spleen cells. Expressed cytokines in the D-glucosamine-treated cells were IL-2, IFN-gamma, and IL-12 p40 subunit. In particular, IFN-gamma was expressed more efficiently, and D-glucosamine was more effective for expressing the cytokine gene. These results suggest chitosan as well as D-glucosamine could induce the expression of cytokines as Th1 subset such as IL-2, IFN-gamma.

Time course study of cytokine mRNA expression in LPS-stimulated porcine alveolar macrophages

The kinetics of cytokine mRNA expression was studied in porcine alveolar macrophages using an RT-PCR assay. The expression levels of IFN- gamma, IL-2, IL-4, IL-6, GM-CSF, IL-12 p35, and IL-12 p40 were examined after 2, 4, 14, 24, 48, and 72 h of incubation in unstimulated control and LPS-stimulated cells. The expression contents of IFN-gamma, IL-2, and IL-4 were not detected in both unstimulated and LPS-stimulated cells. On the other hand, the expression levels of IL-6, GM-CSF, and IL-12 in LPS-stimulated cells were almost always higher than those in control cells. Among those cytokines, IL-6 exhibited the predominant expression, and GM-CSF, IL-12 p40, and IL-12 p35 followed in the descending order. The times to reach the peak expression levels for IL-6, and GM-CSF, IL-12 p35, and IL-12 p40 were 14, and 24 h, respectively. After reaching the peak expression point, the expression levels of IL-6, GM-CSF, and IL-12 p40 reduced to the baseline by 72 h after stimulation, however, IL-12 p35 still kept a substantial expression by the same time. This study demonstrates that porcine alveolar macrophages primarily respond to express IL-6, GM-CSF, and IL-12 by LPS-stimulation and have a cytokine-specific expression profile during the stimulation time.

Endocarditis associated with Escherichia coli in a sea lion (Zalophus californianus)

Endocarditis associated with Escherichia coli was diagnosed in a 2-year-old male California sea lion (Zalophus californianus). The diagnosis was based on light microscopic examination and bacterial isolation from the valvular lesion. This is the first case of bacterial endocarditis reported in a sea lion.

Encephalomyelitis associated with akabane virus infection in adult cows

Between August and September 2000, five 2-7-year-old cows in Korea exhibited neurologic signs and were diagnosed as infected with Akabane virus based on the results of histopathology, immunohistochemistry, serology, and reverse transcription polymerase chain reaction (RT-PCR) analysis. Immunohistochemistry and RT-PCR were equally effective and sensitive for diagnosing Akabane virus infection during the early stage of infection. Typical lymphohistiocytic inflammation characterized by perivascular mononuclear cell infiltration, gliosis, neuronophagia, and neuronal loss was noted in the brain and the ventral horn gray matter of the spinal cord. The lesions in the brain were most prominent in the pons and medulla oblongata. Akabane virus antigen was detected in the brain and spinal cord, mainly in degenerating neurons and glial cells. RT-PCR analysis revealed a target band of expected size in four cows. This is the first report on an outbreak of natural Akabane virus infection in adult cattle.

Morganelliasis pneumonia in a captive jaguar

Suppurative bronchopneumonia was discovered in a 6-yr-old male jaguar (Panthera onca onca) that died after a 1 wk history of anorexia, depression, and respiratory difficulty. Morganella morganii was isolated as a pure culture from the lung, spleen, and heart blood. This is the first record of M. morganii induced pneumonia in a jaguar.

Gallbladder lymphangioma: MR findings

Intraabdominal lymphangiomas are rare lesions that can be difficult to diagnose. We report ultrasonographic (US), computed tomographic (CT), magnetic resonance (MR) imaging, and pathologic findings in a patient with cavernous lymphangioma originating in the gallbladder. US and CT showed a multiseptated cystic mass in the gallbladder fossa. T2-weighted MR images and MR cholangiopancreatography depicted the lumen of the gallbladder and thin septations of the cystic mass, which originated in the gallbladder. Endoscopic retrograde cholangiopancreatography showed no apparent communication between the cyst and the gallbladder. Histologic findings obtained during the operation were consistent with cavernous lymphangioma. Its characteristic histology was observed in the subserosal layer of the gallbladder. This case is a rare instance of cavernous lymphangioma originating in the gallbladder preoperatively diagnosed by MR and MR cholangiopancreatography.

Pleckstrin homology domain interacts with Rkp1/Cpc2, a RACK1 homolog, to modulate Pck2-mediated signaling process in Schizosaccharomyces pombe

Rkp1/Cpc2, a fission yeast RACK1 homolog, interacts with Pck2, a PKC homolog, and is involved in the regulation of pck2-mediated signaling process. The N-terminal region of split pleckstrin homology domain (nPH) in human PLC-gamma1 bound to Rkp1/Cpc2 concomitantly with Pck2. nPH inhibited kinase activity of GST-Pck2 purified from Schizosaccharomyces pombe in vitro. The lethality induced by pck2(+) overexpression was suppressed by coexpression of either rkp1(+) or nPH domain. This result suggests that Rkp1/Cpc2 interacts with PH domain-containing protein and regulates the Pck2-mediated signaling process in S. pombe.