The susceptibility of magpies to a highly pathogenic avian influenza virus subtype H5N1

Korean wild magpies (Pica pica sericea) were intranasally inoculated with highly pathogenic avian influenza (A/Chicken/Korea/ES/03 virus) (H5N1), which was classified as clade 2.5. We estimated viral replication, death after infection, and histology and immunohistochemistry. This species was highly susceptible to severe infection; 100% of birds died within 5 to 8 d. The virus was detected from oropharyngeal (1 to 5 d postinfection) and cloacal (3 to 5 d postinfection) swabs from infected magpies. At necropsy, the prominent lesions were coalescing necrosis of the pancreas with enlargement of livers and spleens. Microscopically, pancreas, brain, heart, adrenal gland, and kidney were most consistently affected with necrotic and inflammatory changes, and viral antigen was frequently demonstrated in the parenchyma of these organs. As a result, Korean wild magpies were very susceptible to avian influenza (H5N1) virus.

Development of a stabilizer for lyophilization of an attenuated duck viral hepatitis vaccine

The live attenuated vaccine against duck viral hepatitis currently available in Korea requires special freezers for storage and transportation with extra costs involved. The development of a lyophilization stabilizer for live attenuated duck viral hepatitis virus (DHV) vaccines, therefore, has been highly recommended for the wider application of the vaccines. Four conventional vaccine stabilizer formulations containing a disaccharide, such as lactose, trehalose, or sucrose, and new formulations containing sorbitol were tested for their efficacy in stabilizing a new attenuated DHV type 3 vaccine candidate under different storage temperatures, 4 and 37 degrees C. The vaccine virus and each stabilizer formulation were combined and submitted to lyophilization and the viability of the virus was measured in 7-d-old specific-pathogen-free chicken embryos by determining the 50% egg lethal dose. Stabilizer formulations containing 2, 4, or 8% sorbitol preserved the viability of the vaccine virus much better than the other stabilizer formulations and 2% sorbitol was the optimal concentration in a standard stabilizing buffer, phosphate glutamate gelatin (0.0038 M KH2PO4, 0.0071 M K2HPO4, 0.0049 M monosodium L-glutamate, and 0.5% gelatin). The results demonstrate that the stabilizer formulation containing 2% sorbitol and 0.5% gelatin can be used for convenient storage and transportation of live DHV vaccines.

Effects of 20-Week Intermittent Cold-Water-Immersion on Phenotype and Myonuclei in Single Fibers of Rat Hindlimb Muscles

The effects of 20 weeks of intermittent cold-water-immersion on myosin heavy chain (MHC) expression,cross-sectional area (CSA), myonuclear number, and myonuclear domain size in isolated single fiber of soleus and extensor digitorum longus (EDL) muscles were studied in male Wistar rats. Cold exposure was accomplished by submerging the rats in shoulder-deep water, maintained at approximately 18 degrees C, for 1 hour/day, 5 days/week and for 20 weeks. Cold exposure resulted in a significant inhibition of body and soleus muscle weight gain. The percent type IIa MHC fibers of EDL muscle was increased, whereas that of type IIa + b MHC fibers was less in cold-exposed group than controls (p < 0.05). The mean CSA and myonuclear number in type I MHC fibers of soleus muscle in cold-exposed group were significantly less than controls. Myonuclear domain in type IIa fibers of EDL in the cold-exposed group was greater than controls (p < 0.05). It is suggested that prolonged cold exposure causes the fiber-type-specific adaptation in rat hindlimb muscles. It is further indicated that cold-exposure-related modulation of myonuclear number was closely related to reduction of fiber CSA, not the shift of fiber phenotype.

Establishment and characterization of two new cell lines derived from flounder, Paralichthys olivaceus (Temminck & Schlegel)

Two new cell cultures from flounder, Paralichthys olivaceus (Temminck & Schlegel), flounder fin (FFN) cells from fin tissue and flounder spleen (FSP) cells from spleen tissue, were established and characterized. The cells multiplied well in Eagle's minimum essential medium, supplemented with 10% foetal bovine serum, and have been subcultured more than 100 times, becoming continuous cell lines. Modal diploid chromosome number of FFN and FSP cells was 64 and 62, respectively. Polymerase chain reaction products were obtained from FFN and FSP cells with primer sets ofmicrosatellite markers of flounder. Optimal growth temperature was 20 degrees C and consisted of epithelioid cells. FFN and FSP cells showed cytopathic effects after inoculation of infectious pancreatic necrosis virus, marine birnavirus, chum salmon virus, infectious haematopoietic necrosis virus, spring viraemia of carp virus and hirame rhabdovirus. Thus these new cell lines may be useful for studying a wide range of fish viruses.

Acquired activated protein C resistance, high tissue factor expression, and hyper-homocysteinemia in systemic lupus erythematosus

Activated protein C resistance (APCR), high tissue factor (TF) expression, and hyper-homocysteinemia are associated with thromboembolic diseases. Thromboembolism is a frequent complication of systemic lupus erythematosus (SLE). In this study, we evaluated the prevalence of APCR, high TF, and homocysteine with correlation of the thrombotic tendency in SLE. Ninety-four SLE patients and 28 normal controls were included. APC ratio and TF antigen were measured using commercial kits. Plasma homocysteine level was measured using HPLC. The prevalence of APCR, high TF antigen level, and hyper-homocysteinemia in our SLE patients were 21.3%, 66.0%, and 23.4%, respectively. The median plasma level of TF antigen in SLE patients was 145.23 pg/mL (range, 31.00-778.50 pg/mL), which was significantly higher than the control value of 39.83 pg/mL (range, 1.55-168.50 pg/mL). The median APC ratio in SLE patients was 2.76 (range, 1.48-13.47), which was significantly lower than the control value of 3.59 (range, 0.26-5.66). The plasma level of homocysteine was not significantly different from that of control. A significant association was observed between the presence of APCR (OR = 8.59, P < 0.0001) but not with the presence of high plasma TF antigen level (OR = 1.24, P = 0.67) and thrombotic complications in SLE patients. In conclusion, APCR and high plasma TF levels are common in SLE, but a significant association was observed only between the presence of APCR and thrombosis in SLE patients.

Homozygous C677T mutation in the MTHFR gene as an independent risk factor for multiple small-artery occlusions

INTRODUCTION

Hyperhomocysteinemia is an independent risk factor for cerebrovascular disease and the homozygous C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene can induce hyperhomocysteinemia. However, the association between this 677TT genotype and ischemic stroke still remains controversial. Therefore, we carried out this study to determine whether the MTHFR TT genotype is associated with certain subtypes of ischemic stroke.

MATERIALS AND METHODS

We enrolled 195 ischemic stroke patients and 198 healthy individuals and checked their fasting plasma homocysteine levels and analyzed the C677T polymorphism in the MTHFR gene.

RESULTS

Our findings concur with previous reports that stroke occurrence is associated with hyperhomocysteinemia, but not with the 677TT genotype. However, when we re-analyzed the data based on a subtype classification, the adjusted odds ratio (AOR) and 95% confidence intervals (CI) of the 677TT genotype were found to be significantly higher in patients with small-artery occlusion than that in controls (AOR, 2.92; 95% CI, 1.01-8.48). Moreover, the AOR of the 677TT genotype was found to be much bigger in patients with multiple small-artery occlusions (AOR, 6.90; 95% CI, 1.70-27.99), but not in those with single small-artery occlusion (AOR, 1.19; 95% CI, 0.27-5.35).

CONCLUSIONS

The homozygous C677T mutation in the MTHFR gene is associated with multiple small-artery occlusions, but not with single small-artery occlusion. Our findings suggest a genetic basis for certain subtypes of ischemic stroke.

Virulence of recent isolates of Mycoplasma synoviae in turkeys

Systemic Mycoplasma synoviae (MS) infection was induced experimentally in commercial turkeys with recent MS isolates (K4822D and K4774J) from turkey breeder flocks that exhibited no clinical signs typical of MS infection except for a low incidence of swollen footpads. The virulence of each strain was compared by evaluating gross and microscopic lesions, serologic responses, and MS isolation rates at 10 and 21 days postchallenge and by comparing these results with those obtained from a known virulent isolate (K1968), another previously characterized field isolate (K4463B), and unchallenged controls. All strains induced lesions typical of infectious synovitis but showed distinct differences in the extent of the gross and microscopic lesions and in the isolation rates from the tissues in turkeys. K1968 induced the most extensive lesions in hock and stifle joints and footpads, but strains K4822D, K4774J, and K4463B all induced synovitis and were similar in virulence for synovial tissues. Very mild respiratory lesions were induced by all of the strains studied. All strains yielded strong positive serologic responses. We concluded that these recent field isolates, although able to induce synovitis, are less virulent for turkeys than a known virulent strain. Nevertheless, under severe experimental challenge, these strains have the capability of causing lesions that may be incompatible with economical turkey production.

Epstein-Barr virus nuclear antigen 1 activates transcription from episomal but not integrated DNA and does not alter lymphocyte growth

By binding to a cis-acting element (oriP) in the Epstein-Barr virus (EBV) genome, EBV nuclear antigen 1 (EBNA1) enables persistence and enhances transcription from EBV episomes. To investigate whether EBNA1 also directly affects cell gene transcription, we conditionally expressed a Flag-tagged dominant negative EBNA1 (FDNE) in an EBV immortalized lymphoblastoid cell line, in which the EBV genome is integrated into cell DNA. FDNE induction inhibited expression from an EBNA1-dependent oriP reporter plasmid by more than 90% in these cells but did not affect expression from integrated EBV or oriP reporter DNA. FDNE induction also did not alter expression of more than 1,800 cellular mRNAs. Lymphoblastoid cell line growth under a variety of conditions was unaffected by FDNE induction. Although Gal4-VP16 and EBNA1 strongly activated and coactivated a Gal4-VP16- and oriP-dependent promoter that was on an episome, only Gal4-VP16 activated the promoter when it was integrated into chromosomal DNA. These data indicate that EBNA1 is specifically deficient in activation of an integrated oriP enhancer and does not affect cell growth or gene expression through an interaction with cognate chromosomal DNA.

Antinociceptive effects of bee venom acupuncture (apipuncture) in rodent animal models: a comparative study of acupoint versus non-acupoint stimulation

From a clinical perspective, the alternative forms of acupoint stimulation including electroacupuncture, moxibustion and acupressure appear to have more potent analgesic effects than manual needle acupuncture. Bee venom (BV) injection has also been reported to produce persistent nociceptive stimulation and to cause neuronal activation in the spinal cord. In previous study, we observed that BV stimulation into acupoint, namely BV acupuncture or Apipuncture, produced more potent anti-inflammatory and antinociceptive potency in rodent arthritis model as comparing with that of non-acupoint injection. Based on previous report, we decided to further investigate that BV injection into an acupoint produces antinociception as a result of its potent chemical stimulatory effect in both abdominal stretch assay and formalin test. Different doses of BV were injected into an acupoint or a non-acupoint 30 min prior to intraplantar formalin injection or intraperitoneal acetic acid injection. Using the abdominal stretch assay, we found that the high dose of BV (1:100 diluted in 20microl saline) produced a potent antinociceptive effect irrespective of the site of BV injection. In contrast the antinociceptive effect observed in both the writhing and formalin tests following administration of a low dose of BV (1:1000 diluted in 20microl saline) was significantly different between acupoint and non-acupoint sites. BV injection into an acupoint (Zhongwan, Cv. 12) was found to produce significantly greater antinociception than non-acupoint injection (10 mm from Zhongwan, Cv. 12) in the abdominal stretch assay. Similarly, in the formalin test, acupoint (Zusanli, St. 36) injection of BV produced more potent antinociception than non-acupoint injection (gluteal muscle). In contrast, BV injection into an arbitrary non-acupoint site on the back did not produce antinociception in either the writhing or formalin test. These results indicate that BV injection directly into an acupoint can produce a potent antinociceptive effect and suggest that this alternative form of acupoint stimulation (Apipuncture) may be a promising method for the relief of pain.

Visceral antinociception produced by bee venom stimulation of the Zhongwan acupuncture point in mice: role of alpha(2) adrenoceptors

The goal of the present study was to determine whether bee venom (BV) injection into the Zhongwan acupoint (CV12), compared to injection into a non-acupoint, produced antinociception in an acetic acid-induced visceral pain model. This was accomplished by injecting BV subcutaneously into the Zhongwan acupoint or into a non-acupoint 30 min before intraperitoneal injection of acetic acid in ICR mice. BV injection into the acupoint produced a dose dependent suppression of acetic acid-induced abdominal stretches and of acetic acid-induced Fos expression in the spinal cord and the nucleus tractus solitarii. In contrast BV injection into the non-acupoint only produced antinociception at the highest dose of BV tested. Naloxone pretreatment did not alter the antinociceptive effect of BV acupoint injection on the abdominal stretch reflex. On the other hand, pretreatment with the alpha 2-adrenoceptor antagonist, yohimbine completely blocked the antinociceptive effect of BV acupoint injection. These results imply that BV acupoint stimulation can produce visceral antinociception that is associated with activation of alpha 2-adrenoceptors, but not with naloxone-sensitive opioid receptors.

Different frequencies of electroacupuncture modified the cellular activity of serotonergic neurons in brainstem

In this study, we evaluated whether different frequencies of electroacupuncture (EA) modified the activities of serotonergic neurons in the dorsal raphe (DR) and raphe magnus (RMg) using double labeling immunohistochemistry for Fos and serotonin. The results demonstrated that both high and low frequency EA increased the colocalization between Fos and serotonin in the DR, not in RMg as compared with anesthesia control. In addition, high frequency EA more potently increased the serotonergic activity in the DR rather than low frequency EA, suggesting that serotonergic pathway from the DR plays an important role in the high frequency EA analgesia.

Competitive exclusion against Salmonella gallinarum of Salmonella enteritidis infected chickens

To evaluate the degree of competitive exclusion against Salmonella gallinarum(S. gallinarum) of Salmonella enteritidis(S. enteritidis) infected chickens, fifty-six, 4-week old Hyline layer suspected of S. enteritidis infection were challenged with S. gallinarum. All chickens were tested for S. enteritidis isolation using cloacal swabs and serum plate agglutination test using S. enteritidis Ag. before challenge and classified into four groups(SE isolated, SE nonisolated, SE seropositive and SE seronegative). None of the SE isolated and the SE seropositive groups died after challenge and the average weight gains were 245.5g and 254.6g, respectively. But in the SE nonisolated and the SE seronegative groups, mortality was 18.2% and 20.6% and the average weight gains were 150.1g and 111.2g. The incidence of reisolation of S. gallinarum of the SE isolated and the SE seropositive groups were 41.7% and 47.6% from liver, 33.3% and 47.6% from spleen and 8.3% and 14.3% from cecum, respectively, and the SE nonisolated and the SE seronegative group were 63.6% and 64.7% from liver, 84.1% and 88.2% from spleen and 47.7% and 52.9% from cecum. The serological response of the SE isolated and the SE seropositive groups hardly changed from 75.0 and 81.8% before challenge to 75.0 and 85.7% after. But, the other two groups were found to be significantly higher after challenge and increased from 0 and 18.2% to 100%. Consequently, S. enteritidis preinfected chickens were found to be significant different in terms of mortality, weight gain, reisolation of S. gallinarum and serological response compared to noninfected chickens. Moreover, our study shows that S. enteritidis infected chickens appear strong competitive exclusion against the colonization of S. gallinarum.

Human papillomavirus 16/18 expression of endocervical glandular lesions: relationship with p53 and MIB-1 Expressions

The pathogenesis of endocervical glandular lesions are not clearly understood. The aims of this study are to evaluate the etiologic role of human papillomavirus (HPV) 16/18 and the relationship of HPV 16/18, p53 and MIB-1 expressions in endocervical glandular dysplasia (EGD), adenocarcinoma in situ (AIS) and adenocarcinoma. The materials included 14 endocervical adenocarcinoma and 5 AIS and 18 high grade EGD and 39 low grade EGD. Immunohistochemistry for p53 and MIB-1, and in situ PCR for HPV 16/18 were done. HPV 16/18 positivity was 84.2%, 16.7% and 17.9% in malignant glandular lesion (adenocarcinoma and AIS), high grade EGD and low grade EGD, respectively. P53 protein expression rates of malignant glandular lesions, high grade EGD and low grade EGD were 31.6%, 11.1%, and 0%, respectively. High MIB-1 labelling index was found in 73.7% of malignant glandular lesions, but in only 5.7% and 3.6% of high and low grade EGD, respectively. There were statistically significant differences in HPV 16/18, p53 and MIB-1 expressions between malignant endocervical glandular lesions and EGD, but no significant difference in p53 and MIB-1 expressions in relation to HPV 16/18 expression. In malignant endocervical glandular lesions, HPV 16/18 infection may be a major causative factor, but not be related to p53 and MIB-1 expressions.

Maintenance of Epstein-Barr virus (EBV) oriP-based episomes requires EBV-encoded nuclear antigen-1 chromosome-binding domains, which can be replaced by high-mobility group-I or histone H1

EBV-encoded nuclear antigen-1 (EBNA-1) binding to a cis-acting viral DNA element, oriP, enables plasmids to persist in dividing human cells as multicopy episomes that attach to chromosomes during mitosis. In investigating the significance of EBNA-1 binding to mitotic chromosomes, we identified the basic domains of EBNA-1 within amino acids 1-89 and 323-386 as critical for chromosome binding. In contrast, the EBNA-1 C terminus (amino acids 379-641), which includes the nuclear localization signal and DNA-binding domain, does not associate with mitotic chromosomes or retain oriP plasmid DNA in dividing cell nuclei, but does enable the accumulation of replicated oriP-containing plasmid DNA in transient replication assays. The importance of chromosome association in episome maintenance was evaluated by replacing EBNA-1 amino acids 1-378 with cell proteins that have similar chromosome binding characteristics. High-mobility group-I amino acids 1-90 or histone H1-2 could substitute for EBNA-1 amino acids 1-378 in mediating more efficient accumulation of replicated oriP plasmid, association with mitotic chromosomes, nuclear retention, and long-term episome persistence. These data strongly support the hypothesis that mitotic chromosome association is a critical factor for episome maintenance. The replacement of 60% of EBNA-1 with cell protein is a significant step toward eliminating the need for noncellular protein sequences in the maintenance of episomal DNA in human cells.

Increased expression of cyclin D1, cyclin E and p21(Cip1) associated with decreased expression of p27(Kip1) in chemically induced rat mammary carcinogenesis

We induced rat mammary tumors in 7-week-old female Sprague-Dawley rats by intragastric administration of 7,12-dimethylbenz(a)anthracene (DMBA), and analyzed by immunohistochemistry the expression of cyclin D1, cyclin E, p21(Cip1), and p27(Kip1) in carcinomas, atypical tumors, and benign tumors as well as normal mammary glands from the control group. Proliferation status was assessed by immunohistochemistry using bromodeoxyuridine (BrdU). A sequential increase in cyclin D1-, cyclin E-, and p21(Cip1)-positive epithelial cells was observed from normal mammary glands, to atypical tumors, to carcinomas. In contrast, carcinomas showed a significantly lower number of epithelial cells immunoreactive to p27(Kip1) when compared with atypical tumors, benign tumors and normal mammary glands. The immunoreactivities of BrdU, cyclin D1, cyclin E, and p21(Cip1) were positively correlated, whereas that of p27(Kip1) appeared inversely correlated to those of the others. Reverse transcriptase-polymerase chain reaction (RT-PCR) and western blot analysis were also performed to determine the mRNA and protein levels of cyclins and cyclin-dependent kinase inhibitors in tumors and normal mammary glands. The protein levels for cyclin D1, cyclin E and p21(Cip1) in carcinomas and atypical tumors were significantly higher than those in benign tumors, while normal mammary glands showed negligible expression. On RT-PCR, tumors showed higher mRNA levels of cyclin D1 and cyclin E than those of normal mammary glands. Our results suggest that rat mammary carcinogenesis involves increased expression of cyclin D1, cyclin E, and p21(Cip1), associated with decreased expression of p27(Kip1).

Role of paxillin in metabolic oxidative stress-induced cytoskeletal reorganization: involvement of SAPK signal transduction pathway and PTP-PEST gene expression

Previous studies have shown that glucose deprivation-induced cell death is associated with apoptosis, which is characterized by cellular membrane blebbing in multi-drug-resistant human breast carcinoma MCF-7/ADR cells. In this study, we investigated the mechanism of glucose deprivation-induced cytoskeletal reorganization, which is known to be responsible for the morphological alterations. An increase in the formation of focal adhesion and stress fibers was observed during the early period of glucose deprivation (1-2 h). However, a disappearance of focal adhesion complexes and a loss of stress fiber formation along with membrane blebbing were observed when glucose deprivation continued. These alterations were delayed in MCF-7/ADR cells transfected with bcl-2 and completely suppressed by treatment with an antioxidant, N-acetyl-L-cysteine. These results indicated that glucose deprivation-induced oxidative stress caused the cytoskeletal reorganization. The glucose deprivation-induced alteration of cytoskeletal organization was further investigated by studying a modification of paxillin, one of the focal adhesion proteins. Immunoblotting with anti-paxillin antibody showed that the paxillin band shifted from 68 kDa to about 80 kDa during 1-4 h of glucose deprivation. The mobility shift indicated the modification of paxillin. This possibility was further studied by an immunoprecipitation assay with anti-paxillin/anti-phosphotyrosine antibody and phosphoamino acid analysis (PAA). The immunoprecipitation study revealed that the level of tyrosine phosphorylation of paxillin was maintained for 2 h and then markedly decreased without a change in the total level of paxillin. The PAA study showed that paxillin is dephosphorylated on tyrosine concurrent with phosphorylation on serine/threonine. Expression of a dominant-negative mutant of c-Jun NH(2)-terminal kinase (JNK1) suppressed glucose deprivation-induced JNK1 activation, PTP-PEST gene expression, and alteration of paxillin. Taken together, these results suggest that the alteration of the phosphorylation/dephosphorylation of paxillin may be related to the cytoskeletal reorganization and these events are mediated by glucose deprivation-induced oxidative stress and the stress-activated protein kinase signal transduction pathway.

Effects of 9 weeks of hindlimb unloading on motor performances in adult rats

It has been reported that abnormal steps associated with an ankle hyper-extension during walking were observed in adult rats after 2 weeks of hindlimb suspension (Canu and Falempin, 1997 & 1998). But such phenomena were normalized after 7 days of reambulation recovery. Canu and Falempin (1996) suggested that the spinal cord has a capacity to generate a well-organized pattern of locomotion even after a period of muscle disuse. There are, however, no reports about the effects of more prolonged suspension on motor performances. In the present study, 7 weeks old male rats were hindlimb-unloaded by tail suspension for 9 consecutive weeks and landing performances in response to drop from head-down, head-up, or supine position were investigated during 8 weeks of recovery. Posture maintenance during right-left translation was also checked.