Showing papers by "Kangwon National University published in 2005"

β-Carotene inhibits inflammatory gene expression in lipopolysaccharide-stimulated macrophages by suppressing redox-based NF-κB activation

Abstract: β-Carotene has shown antioxidant and antiinflammatory activities; however, its molecular mechanism has not been clearly defined. We exa - mined in vitro and in vivo regulatory function of β-carotene on the production of nitric oxide (NO) and PGE₂ as well as expression of inducible NO synthase (iNOS), cyclooxygenase-2, TNF-α, and IL-1β. β-Carotene inhibited the expression and production of these inflammatory mediators in both LPSstimulated RAW264.7 cells and primary macrophages in a dose-dependent fashion as well as in LPS-administrated mice. Furthermore, this com - pound suppressed NF-κB activation and iNOS promoter activity in RAW264.7 cells stimulated with LPS. β-Carotene blocked nuclear translocation of NF-κB p65 subunit, which correlated with its inhibitory effect on IκBα phosphorylation and degradation. This compound directly blocked the intracellular accumulation of reactive oxygen species in RAW264.7 cells stimulated with LPS as both the NADPH oxidase inhibitor diphenylene iodonium and antioxidant pyrrolidine dithiocarbamate did. The inhibition of NADPH oxidase also inhibited NO production, iNOS expression, and iNOS promoter activity. These results suggest that β-carotene possesses anti-inflammatory activity by functioning as a potential inhibitor for redox-based NF-κB activation, probably due to its antioxidant activity.

Glucose metabolism in early onset versus late onset Alzheimer's disease: an SPM analysis of 120 patients

Abstract: The aims of this cross-sectional study were (i) to compare the overall glucose metabolism between early onset and late onset Alzheimer’s disease in a large sample of patients; and (ii) to investigate the pattern of glucose metabolism as a function of dementia severity in early onset versus late onset Alzheimer’s disease, using a statistical parametric mapping (SPM) analysis. Subjects consisted of four groups: 74 patients with early onset Alzheimer’s disease, 46 patients with late onset of the disease, and two control groups age matched to each patient group. All the subjects underwent 2-[ 18 F]fluoro-2-deoxy-D-glucose (FDG)-PET under the same scanning conditions. Severity of dementia was rated with the Clincial Dementia Rating (CDR). Voxel-based SPM99 was used for statistical analyses. Overall glucose hypometabolism of early onset Alzheimer’s disease patients was much greater in magnitude and extent than that of late onset patients, though both groups were similar in dementia severity: the early onset group showed more severe hypometabolism in parietal, frontal and subcortical (basal ganglia and thalamus) areas. When the decline of glucose metabolism was compared as a function of CDR stage, the slope was steeper in early onset than in late onset Alzheimer’s disease. The rapid decline occurred at CDR 0.5–1 in the early onset group, whereas similar changes occurred at CDR 2–3 in the late onset group. The greater hypometabolism in early onset than in late onset patients is required to reach the same severity of dementia, probably reflecting greater functional reserve in younger than in older subjects. Alternatively, the metabolic decline curve suggests that the early onset patients may take a more rapid course in the reduction of glucose metabolism than the late onset patients.

TNF-Related Activation-Induced Cytokine Enhances Leukocyte Adhesiveness: Induction of ICAM-1 and VCAM-1 via TNF Receptor-Associated Factor and Protein Kinase C-Dependent NF-κB Activation in Endothelial Cells

Abstract: Inflammation is a basic pathological mechanism leading to a variety of vascular diseases The inflammatory reaction involves complex interactions between both circulating and resident leukocytes and the vascular endothelium In this study, we report evidence for a novel action of TNF-related activation-induced cytokine (TRANCE) as an inflammatory mediator and its underlying signaling mechanism in the vascular wall TRANCE significantly increased endothelial-leukocyte cell interactions, and this effect was associated with increased expression of the cell adhesion molecules, ICAM-1 and VCAM-1, on the endothelial cells RT-PCR analysis and promoter assays revealed that expression of these cell adhesion molecules was transcriptionally regulated mainly by activation of the inflammatory transcription factor, NF-kappaB TRANCE induced IkappaB-alpha phosphorylation and NF-kappaB activation via a cascade of reactions involving the TNFR-associated factors, phospholipase C, PI3K, and protein kinase C (PKC-alpha and PKC-zeta) It also led to the production of reactive oxygen species via PKC- and PI3K-dependent activation of NADPH oxidase in the endothelial cells, and antioxidants suppressed the responses to TRANCE These results demonstrate that TRANCE has an inflammatory action and may play a role in the pathogenesis of inflammation-related diseases

GIS-based sediment assessment tool

Abstract: Accelerated soil erosion is a worldwide problem because of its economic and environmental impacts. To effectively estimate soil erosion and to establish soil erosion management plans, many computer models have been developed and used. The Revised Universal Soil Loss Equation (RUSLE) has been used in many countries, and input parameter data for RUSLE have been well established over the years. However, RUSLE cannot be used to estimate the sediment yield for a watershed. Thus, the GIS-based Sediment Assessment Tool for Effective Erosion Control (SATEEC) was developed to estimate soil loss and sediment yield for any location within a watershed using RUSLE and a spatially distributed sediment delivery ratio. SATEEC was enhanced in this study by developing new modules to: 1) simulate the effects of sediment retention basins on the receiving water bodies, 2) estimate the sediment yield from a single storm event, and 3) prepare input parameters for the Web-based sediment decision support system using a GIS interface. The enhanced SATEEC system was applied to the study watershed to demonstrate how the enhanced system can be effectively used for soil erosion control. All the procedures are fully automated with Avenue, CGI, and database programming; thus the enhanced SATEEC system does not require experienced GIS users to operate the system. This easy-to-operate SATEEC system can be used to identify areas vulnerable to soil loss and to develop efficient soil erosion management plans.

Photodegradation of gaseous volatile organic compounds (VOCs) using TiO2 photoirradiated by an ozone-producing UV lamp: decomposition characteristics, identification of by-products and water-soluble organic intermediates

Abstract: The photodegradation of the toluene and benzene with TiO2 (P25) and UV254+185 nm radiation from an ozone-producing UV lamp was studied. The VOCs were decomposed and mineralized efficiently owing to the synergistic effect of photochemical oxidation in the gas phase and photocatalytic oxidation on the TiO2 surface. The conversion levels obtained with UV254+185 nm photoirradiated TiO2 were much higher than those with conventional UV sources (UV365 nm and UV254 nm), which suffer from both catalyst deactivation and the generation of harmful intermediates. The products from the photodegradation of VOCs with the UV254+185 nm photoirradiated TiO2 were mainly mineralized CO2 and CO, but some water-soluble organic intermediates were also formed under more severe reaction conditions. The water-soluble aldehydes and carboxylic intermediates disappeared from the effluent gas stream and were detected in the water impingers. These findings suggest that the intermediates can be washed out by conventional gas washing technique, such as wet scrubber. Excess ozone could be easily removed by means of an MnO2 ozone-decomposition catalyst.

Prognostic factors for the surgery for mesial temporal lobe epilepsy: longitudinal analysis.

Abstract: Summary: Purpose: Determining long-term prognostic factors of surgery for mesial temporal lobe epilepsy (MTLE) is important for identifying ideal candidates and predicting the prognosis for individual patients We tried to identify the prognostic factors of anterior temporal lobectomy (ATL) for MTLE with longitudinal multivariate analysis Methods: Two hundred twenty-seven patients with MTLE were included in this study The primary outcome variable was patient status 1–5 years after surgery: seizure free, or not Clinical characteristics and recent diagnostic modalities were considered as prognostic factors Univariate and standard multiple logistic-regression analysis for outcome at 1 and 5 years after surgery and the generalized estimation equation (GEE) model for longitudinal multiple logistic regression of the 5-year follow-up period were used Results: The seizure-free rate at 1 year was 811% and decreased to 752% at 5 years after surgery By the univariate or standard multiple logistic-regression analysis, age at surgery or hippocampal sclerosis on magnetic resonance imaging (MRI) ipsilateral to surgery was significant for the postsurgical outcome However, the longitudinal analysis by the GEE model revealed that younger age at surgery [odds ratio (OR), 059; 95% confidence interval (CI), 043–081], absence of secondarily generalized tonic–clonic seizure (2°GTCS; OR, 045; 95% CI, 026–079), and hippocampal sclerosis on MRI (OR, 244; 95% CI, 111–526) were significant predictors of a good surgical outcome Conclusions: Age at surgery, presence of 2°GTCS, and hippocampal sclerosis on MRI are independent prognostic factors for ATL in MTLE These findings suggest that MTLE is a progressive disorder, and surgical outcome is better when early ATL is performed

A comparison of the knowledge-based innovation systems in the economies of South Korea and the Netherlands using Triple Helix indicators

Abstract: This paper elaborates on the Triple Helix model for measuring the emergence of a knowledge base of socio-economic systems. The ‘knowledge infrastructure’ is measured using multiple indicators: webometric, scientometric, and technometric. The paper employs this triangulation strategy to examine the current state of the innovation systems of South Korea and the Netherlands. These indicators are thereafter used for the evaluation of the systemness in configurations of university-industry-government relations. South Korea is becoming somewhat stronger than the Netherlands in terms of scientific and technological outputs and in terms of the knowledge-based dynamics; South Korea’s portfolio is more traditional than that of the Netherlands. For example, research and patenting in the biomedical sector is underdeveloped. In terms of the Internet-economy, the Netherlands seem oriented towards global trends more than South Korea; this may be due to the high component of services in the Dutch economy.

Prostaglandin E2 stimulates angiogenesis by activating the nitric oxide/cGMP pathway in human umbilical vein endothelial cells.

Abstract: Prostaglandin E₂ (PGE₂), a major product of cyclooxygenase, has been implicated in modulating angiogenesis, vascular function, and inflammatory processes, but the underlying mechanism is not clearly elucidated. We here investigated the molecular mechanism by which PGE₂ regulates angiogenesis. Treatment of human umbilical vein endothelial cells (HUVEC) with PGE₂ increased angiogenesis. PGE₂ increased phosphorylation of Akt and endothelial nitric oxide synthase (eNOS), eNOS activity, and nitric oxide (NO) production by the activation of cAMP-dependent protein kinase (PKA) and phosphatidylinositol 3-kinase (PI3K). Dibutyryl cAMP (DB-cAMP) mimicked the role of PGE₂ in angiogenesis and the signaling pathway, suggesting that cAMP is a down-stream mediator of PGE₂. Furthermore, PGE₂ increased endothelial cell sprouting from normal murine aortic segments, but not from eNOS-deficient ones, on Matrigel. The angiogenic effects of PGE₂ were inhibited by the inhibitors of PKA, PI3K, eNOS, and soluble guanylate cyclase, but not by phospholipase C inhibitor. These results clearly show that PGE₂ increased angiogenesis by activating the NO/cGMP signaling pathway through PKA/PI3K/Akt-depen - dent increase in eNOS activity.

Purification and characterization of laccase from the white rot fungus Trametes versicolor.

Abstract: Laccase is one of the ligninolytic enzymes of white rot fungus Trametes versicolor 951022, a strain first isolated in Korea. This laccase was purified 209-fold from culture fluid with a yield of 6.2% using ethanol precipitation, DEAE-Sepharose, Phenyl-Sepharose, and Sephadex G-100 chromatography. T. versicolor 951022 excretes a single monomeric laccase showing a high specific activity of 91,443 U/mg for 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) as a substrate. The enzyme has a molecular mass of approximately 97 kDa as determined by SDS-PAGE, which is larger than those of other laccases reported. It exhibits high enzyme activity over broad pH and temperature ranges with optimum activity at pH 3.0 and a temperature of 50 degrees C. The Km value of the enzyme for substrate ABTS is 12.8 micrometer and its corresponding Vmax value is 8125.4 U/mg. The specific activity and substrate affinity of this laccase are higher than those of other white rot fungi, therefore, it may be potentially useful for industrial purposes.

Coumarin-strapped calix[4]pyrrole: a fluorogenic anion receptor modulated by cation and anion binding.

Abstract: A new strapped calix[4]pyrrole containing a fluorophore as part of the strap has been synthesized and characterized. Association constants with various anions have been determined using both fluorescence titration and isothermal titrations calorimetry (ITC). The two sets of association constants were found to be in good agreement with one another. The fluorescence emission properties of this new receptor could be controlled by addition of Na+ (or H2O) and anions. However, the fluorescence quenching by anions is only observed in the presence of Na+ (or H2O). All the experimental evidence is consistent with the notion that independent PET processes are modulated by separate cation and anion recognition events. As such, this system operates as an elementary logic gate wherein anion and cation concentrations serve as the input and fluorescence intensity changes provide the output.

Hepatocyte Growth Factor Suppresses Vascular Endothelial Growth Factor-Induced Expression of Endothelial ICAM-1 and VCAM-1 by Inhibiting the Nuclear Factor-κB Pathway

Abstract: Vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) are potent angiogenic factors that have been used clinically to induce angiogenesis. However, concerns have been raised about VEGF because of its proinflammatory actions, which include enhancing the adhesion of leukocytes to endothelial cells. We have examined the possible antiinflammatory effects of HGF on the vasculature. HGF, unlike VEGF, did not alter leukocyte adhesion to endothelial cells. Instead it inhibited VEGF-induced leukocyte-endothelial cell interactions and the endothelial expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). In a skin inflammation model, VEGF-treated mice showed a significant increase of leukocytes infiltrated or adherent to the luminal surface of blood vessels, as compared with vehicle- or HGF-treated mice. The VEGF effect was markedly suppressed by coadministration of HGF. RT-PCR and promoter analysis revealed that HGF downregulated VEGF-mediated expression of ICAM-1 and VCAM-1 at the transcriptional level. Furthermore, these inhibitory effects coincided with suppression of IkappaB kinase activity, and this in turn prevented the activation of the inflammatory transcription factor NF-kappaB. Taken together, our results demonstrate that HGF suppresses VEGF-induced inflammation presumably by inhibiting the endothelial NF-kappaB pathway. This suggests that combined treatment with HGF and VEGF could be superior to treatment with either factor alone for enhancing therapeutic angiogenesis while avoiding inflammation.

Mixed infections with Opisthorchis viverrini and intestinal flukes in residents of Vientiane Municipality and Saravane Province in Laos.

Abstract: Faecal examinations for helminth eggs were performed on 1869 people from two riverside localities, Vientiane Municipality and Saravane Province, along the Mekong River, Laos. To obtain adult flukes, 42 people positive for small trematode eggs (Opisthorchis viverrini, heterophyid, or lecithodendriid eggs) were treated with a 20-30 mg kg(-1) single dose of praziquantel and purged. Diarrhoeic stools were then collected from 36 people (18 in each area) and searched for helminth parasites using stereomicroscopes. Faecal examinations revealed positive rates for small trematode eggs of 53.3% and 70.8% (average 65.2%) in Vientiane and Saravane Province, respectively. Infections with O. viverrini and six species of intestinal flukes were found, namely, Haplorchis taichui, H. pumilio, H. yokogawai, Centrocestus caninus, Prosthodendrium molenkampi, and Phaneropsolus bonnei. The total number of flukes collected and the proportion of fluke species recovered were markedly different in the two localities; in Vientiane, 1041 O. viverrini (57.8 per person) and 615 others (34.2 per person), whereas in Saravane, 395 O. viverrini (21.9 per person) and 155207 others (8622.6 per person). Five people from Saravane harboured no O. viverrini but numerous heterophyid and/or lecithodendriid flukes. The results indicate that O. viverrini and several species of heterophyid and lecithodendriid flukes are endemic in these two riverside localities, and suggest that the intensity of infection and the relative proportion of fluke species vary by locality along the Mekong River basin.

Neuroprotective effects of 3,5-dicaffeoylquinic acid on hydrogen peroxide-induced cell death in SH-SY5Y cells.

Abstract: Oxidative stress plays an important role in the pathological processes of a variety of neurodegenerative diseases. The neuroprotective effects of 3,5-diCQA and 3,4-diCQA, two caffeoylquinic acid derivatives present in Dipsacus asper, on hydrogen peroxide (H2O2)-induced neuronal cell damage were evaluated in this study. SH-SY5Y cells treated with H2O2 exhibited a decrease in survival and intracellular glutathione and also an increase in the caspase-3 activity. However, pretreatment of cells with 3,5-diCQA attenuated the neuronal death and caspase-3 activation induced by H2O2. In addition, 3,5-diCQA restored H2O2-induced depletion of intracellular glutathione. 3,5-diCQA showed significant protective effects although it could not completely suppress H2O2-induced cell injury to control levels. The data suggest that 3,5-diCQA might be a potential therapeutic agent for treating or preventing neurodegenerative diseases implicated with oxidative stress. Copyright © 2005 John Wiley & Sons, Ltd.

Headache in pediatric moyamoya disease: review of 204 consecutive cases

Abstract: Object. Patients with moyamoya disease complain of headache before surgery, after surgery, or in both periods. To clarify the pathophysiological features of these headaches which are one of the major symptoms in moyamoya disease after indirect bypass surgery, the authors reviewed data obtained in patients with moyamoya disease who underwent such surgery at their institute. Methods. The authors surveyed 204 children with moyamoya disease younger than 17 years of age who underwent indirect bypass surgery consecutively between 1988 and 2000. If headache and associated symptoms disturbed their daily activity, required rest and/or medication, and occurred at least once a month, the headache was regarded as significant and the patient was included in the study. A postoperative headache was defined as the presence of significant headache 12 months after the operation or later. Preoperative headache was documented in 44 patients. Postoperative headache was observed in 63% (28 of 44) of the patients with preoperative headache and in 6.3% (10 of 160) of those without preoperative headache. Aggravation on postoperative magnetic resonance images or single-photon emission computerized tomography scans did not correlate with this symptom (p = 0.729 and 0.203, respectively). The clinical course had the following features: 1) a coexisting stage of headache and transient ischemic attack; 2) a second stage of headache only; and 3) a final stage of improvement or disappearance of headache. Conclusions. The authors demonstrated that headaches can persist or develop after indirect bypass surgery despite successful prevention of cerebral ischemia. In addition to decreased cerebral blood flow, progressive recruitment and redistribution of blood flow should be considered as a cause of headaches in patients with moyamoya disease.

Lecture notes in computer science : Packet error rate analysis of IEEE 802.15.4 under IEEE 802.11b interference

Abstract: In this paper, the packet error rate (PER) of IEEE 802.15.4 low rate wireless personal area network (WPAN) under the interference of IEEE 802.11b wireless local area network (WLAN) is analyzed. The PER is obtained from the bit error rate (BER) and the collision time. The BER is obtained from signal to noise and interference ratio. The power spectral density of the IEEE 802.11b is considered in order to determine in-band interference power of the IEEE 802.11b to the IEEE 802.15.4. The simulation results are shown to validate the numerical analysis.

Effect of solubilizing and microemulsifying excipients in polyethylene glycol 6000 solid dispersion on enhanced dissolution and bioavailability of ketoconazole.

Abstract: Polyethylene glycol (PEG) 6000-based solid dispersions (SDs), by incorporating various pharmaceutical excipients or microemulsion systems, were prepared using a fusion method, to compare the dissolution rates and bioavailabilities in rats. The amorphous structure of the drug in SDs was also characterized by powder X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). The ketoconazole (KT), as an antifungal agent, was selected as a model drug. The dissolution rate of KT increased when solubilizing excipients were incorporated into the PEG-based SDs. When hydrophilic and lipophilic excipients were combined and incorporated into PEG-based SDs, a remarkable enhancement of the dissolution rate was observed. The PEG-based SDs, incorporating a self microemulsifying drug delivery system (SMEDDS) or microemulsion (ME), were also useful at improving the dissolution rate by forming a microemulsion or dispersible particles within the aqueous medium. However, due to the limited solubilization capacity, these PEG-based SDs showed dissolution rates, below 50% in this study, under sink conditions. The PEG-based SD, with no pharmaceutical excipients incorporated, increased the maximum plasma concentration (Cmax) and area under the plasma concentration curve (AUC0.6h) two-fold compared to the drug only. The bioavailability was more pronounced in the cases of solubilizing and microemulsifying PEG-based SDs. The thermograms of the PEG-based SDs showed the characteristic peak of the carrier matrix around 60°C, without a drug peak, indicating that the drug had changed into an amorphous structure. The diffraction pattern of the pure drug showed the drug to be highly crystalline in nature, as indicated by numerous distinctive peaks. The lack of the numerous distinctive peaks of the drug in the PEG-based SDs demonstrated that a high concentration of the drug molecules was dissolved in the solid-state carrier matrix of the amorphous structure. The utilization of oils, fatty acid and surfactant, or their mixtures, in PEG-based SD could be a useful tool to enhance the dissolution and bioavailability of poorly water-soluble drugs by forming solubilizing and microemulsifying systems when exposed to gastrointestinal fluid.

Phylogenetic analysis of the genera Bradyrhizobium, Mesorhizobium, Rhizobium and Sinorhizobium on the basis of 16S rRNA gene and internally transcribed spacer region sequences.

Abstract: A total of 128 strains was isolated from more than 23 legume hosts in Korea. Phylogenetic relationships between these Korean isolates and reference strains of the genera Bradyrhizobium, Mesorhizobium, Rhizobium and Sinorhizobium were analysed using their 16S rRNA gene and internally transcribed spacer (ITS) region sequences. Among the Bradyrhizobium strains, dendrograms based on both the 16S rRNA gene and ITS region sequences produced two main groups. The ITS tree yielded at least two new clusters that were discernable from the seven previously delineated genospecies. Large discrepancies were revealed between phylogenetic dendrograms based on 16S rRNA gene and ITS region sequences for members of the genus Rhizobium, reflecting their taxonomic heterogeneity. The amalgamation of Rhizobium and former members of Agrobacterium was confirmed using the 16S rRNA tree. Phylogenetic analysis of ITS region sequences showed that the Rhizobium giardinii clade (group II) and the Rhizobium radiobacter/Rhizobium rubi clade (group III) could be tentatively recognized as groups that are separable from the core group (group I), which includes Rhizobium leguminosarum. Dendrograms based on the 16S rRNA gene and ITS region sequences of Mesorhizobium strains were highly conflicting due to the poor taxonomic resolution of the 16S rRNA gene sequences and the low confidence in the ITS dendrogram. Several Korean isolates within the genus Mesorhizobium are thought to represent novel taxa when considering their relatively low ITS region sequence similarities (<80 %) to the reference strains.

Fucoidan inhibits cellular and neurotoxic effects of β‐amyloid (Aβ) in rat cholinergic basal forebrain neurons

Abstract: The deposition of beta-amyloid protein (A beta), a 39-43 amino acid peptide, in the brain and a loss of cholinergic neurons in the basal forebrain are pathological hallmarks of Alzheimer's disease (AD). Seaweeds consumed in Asia contain Fucoidan, a sulfated polysaccharide. Fucoidan has been known to exhibit various biological actions, such as an anti-inflammatory and antioxidant action. In this study, using whole-cell patch clamp recordings we examined the effects of Fucoidan on A beta-induced whole-cell currents in acutely dissociated rat basal forebrain neurons. We further investigated whether Fucoidan is capable of blocking A beta neurotoxicity in primary neuronal cultures. In dissociated cells, bath application of A beta(25-35) (1 microM) caused a reduction of the whole-cell currents by 16%. Fucoidan, in a dose-dependent manner, blocks the A beta(25-35) reduction of whole-cell currents. Exposure of A beta(25-35) (20 microM) or A beta(1-42) (20 microM) to rat cholinergic basal forebrain cultures for 48 h resulted in 40-60% neuronal death, which was significantly decreased by pretreatment of cultures with Fucoidan (0.1-1.0 microM). Fucoidan also attenuated A beta-induced down-regulation of phosphorylated protein kinase C. A beta(1-42)-induced generation of reactive oxygen species was blocked by prior exposure of cultures to Fucoidan. Furthermore, A beta activation of caspases 9 and 3, which are signaling pathways implicated in apoptotic cell death, is blocked by pretreatment of cultures with Fucoidan. These results show that Fucoidan is able to block A beta-induced reduction in whole-cell currents in basal forebrain neurons and has neuroprotective effects against A beta-induced neurotoxicity in basal forebrain neuronal cultures.

Data from 11 years of molecular typing infectious bronchitis virus field isolates.

Abstract: In 1993, a new molecular typing method for infectious bronchitis virus (IBV) was introduced. This method uses reverse transcriptase-polymerase chain reaction (RT-PCR) and restriction fragment length polymorphism (RFLP) analysis of the spike gene to obtain RFLP patterns that correlate with serotype. Using that test at the Poultry Diagnostic and Research Center (PDRC, University of Georgia, Athens, GA), we have identified a total of 1523 IBV isolates in the past 11 yr. The data were obtained from clinical samples submitted to our laboratory from birds with clinical signs characteristic of IBV infection. The samples are primarily from the southeastern United States but are also from many other states as well as from outside the United States. Most of the isolations occurred during July, followed by May, April, November, October, and January. The fewest number of isolates identified on an annual basis was 20 in 2003. An unusually high number of isolations occurred in 1997 (318 isolations) and 1999 (246 isolations), which coincided with the GAV variant virus and GA98 variant virus outbreaks respectively. By far, the Ark-DPI strain was the most frequently identified type of IBV and ranged from 23% to 65% of total isolations per year. Ark-like isolates, defined as having a similar but unique RFLP pattern from the Ark-DPI vaccine strain were identified every year of the study except in 1996. In addition, new Ark-like isolates continued to emerge each year (except in the year 2000) beginning in 1997, reflecting the ability of that IBV type to undergo genetic drift. Eighty-two different variant viruses were identified although only two (GAV and GA98) became persistent and caused widespread disease. Some viruses tended to be geographically restricted to a given area (CAV in California and MX97-8147 in Mexico), whereas others were widespread (Ark-DPI, Conn, DE072, and Mass). The Florida, Gray, Holte, Iowa, and JMK types were not detected during the 11-yr period, and no foreign virus types were detected in the United States. These data show that IBV variant viruses are consistently circulating in commercial poultry and are capable of causing disease outbreaks. Our observations highlight the importance of constantly monitoring IBV as well as other coronaviruses like severe acute respiratory syndrome-coronavirus that have the ability to change and emerge to cause disease in a susceptible host.

Effects of Supplemental Ascorbic Acid on the Performance and Immunity of Commercial Broilers

Abstract: SUMMARY An experiment was conducted to evaluate the efficacy of supplemental ascorbic acid on the performance of broiler chickens. Three hundred thirty Ross chicks were divided into 5 groups of 66 each, comprising 3 replicates. They were fed 0, 10, 50, 100, and 200 ppm of supplemental ascorbic acid, respectively, for a period of 6 wk. The performance data revealed significantly higher weight gains in the supplemental groups at higher levels as compared with control. The nutrients’ digestibility during starter and finisher phases was significantly higher at higher levels of supplementation. The carcass traits were significantly better in supplemented groups than the control; however, abdominal fat percentage was not affected. The bone resistance was improved at higher levels of ascorbic acid supplementation, since the bone mineral content (Ca and P) was higher in these groups. As the levels of supplementation increased, the ascorbic acid content in plasma and liver also increased linearly. The lymphocyte subpopulation measured showed higher CD4 and T-cell receptor-II (TCR-II) cells in the 100-ppm supplemented group as compared with its counterparts. The infectious bursal disease (IBD) and Newcastle disease (ND) titers measured postvaccination showed significantly higher IBD titers in the 200-ppm group. It can be concluded from the above study that supplementation of ascorbic acid at 200 ppm is beneficial for improving the performance and immunity and for exploiting the full genetic potential of the commercial broilers.