Molecular epidemiology of Japanese encephalitis virus circulating in South Korea, 1983-2005

We sequenced the envelope (E) gene of 17 strains of the Japanese encephalitis virus (JEV) isolated in South Korea in 1983-2005 and compared the sequences with those from previously reported strains. Our results show the remarkable genetic stability of the E gene sequence in Korean JEV strains. Five pairs of E gene sequences from 10 Korean strains were identical, despite geographical differences and a maximum five-year time span. Sequence comparisons with other Asian strains revealed that the Korean strains are closely related to those from China, Japan, and Vietnam. Genotype 3 strains were predominant in Korea before 1993, when genotype 1 strain K93A07 was first isolated. The two genotypes were detected simultaneously in 1994 but since then, only genotype 1 has been isolated in South Korea. Thus, the genotype change occurred according to the year of isolation rather than the geographical origin

Throughput Fairness Enhancement Using Differentiated Channel Access in Heterogeneous Sensor Networks

Nowadays, with wireless sensor networks (WSNs) being widely applied to diverse applications, heterogeneous sensor networks (HSNs), which can simultaneously support multiple sensing tasks in a common sensor field, are being considered as the general form of WSN system deployment. In HSNs, each application generates data packets with a different size, thereby resulting in fairness issues in terms of the network performance. In this paper, we present the design and performance evaluation of a differentiated channel access scheme (abbreviated to DiffCA) to resolve the fairness problem in HSNs. DiffCA achieves fair performance among the application groups by providing each node with an additional backoff counter, whose value varies according to the size of the packets. A mathematical model based on the discrete time Markov chain is presented and is analyzed to measure the performance of DiffCA. The numerical results show that the performance degradation of disadvantaged application groups can be effectively compensated for by DiffCA. Simulation results are given to verify the accuracy of the numerical model

Identification and Characterization of a Dual-Acting Antinematodal Agent against the Pinewood Nematode, Bursaphelenchus xylophilus

The pinewood nematode (PWN), Bursaphelenchus xylophilus, is a mycophagous and phytophagous pathogen responsible for the current widespread epidemic of the pine wilt disease, which has become a major threat to pine forests throughout the world. Despite the availability of several preventive trunk-injection agents, no therapeutic trunk-injection agent for eradication of PWN currently exists. In the characterization of basic physiological properties of B. xylophilus YB-1 isolates, we established a high-throughput screening (HTS) method that identifies potential hits within approximately 7 h. Using this HTS method, we screened 206 compounds with known activities, mostly antifungal, for antinematodal activities and identified HWY-4213 (1-n-undecyl-2-[2-fluorphenyl] methyl-3,4-dihydro-6,7-dimethoxy-isoquinolinium chloride), a highly water-soluble protoberberine derivative, as a potent nematicidal and antifungal agent. When tested on 4 year-old pinewood seedlings that were infected with YB-1 isolates, HWY-4213 exhibited a potent therapeutic nematicidal activity. Further tests of screening 39 Caenorhabditis elegans mutants deficient in channel proteins and B. xylophilus sensitivity to Ca2+ channel blockers suggested that HWY-4213 targets the calcium channel proteins. Our study marks a technical breakthrough by developing a novel HTS method that leads to the discovery HWY-4213 as a dual-acting antinematodal and antifungal compound

Cytoprotective effects of fermented oyster extracts against oxidative stress-induced DNA damage and apoptosis through activation of the Nrf2/HO-1 signaling pathway in MC3T3-E1 osteoblasts

Osteoblast damage by oxidative stress has been recognized as a cause of bone-related disease, including osteoporosis. Recently, we reported that fermented Pacific oyster (Crassostrea gigas) extracts (FO) inhibited osteoclastogenesis and osteoporosis, while promoting osteogenesis. However, since the beneficial potential of FO on osteoblasts is not well known, in the present study, we investigated the cytoprotective effect of FO against oxidative stress in MC3T3-E1 osteoblasts. Our results demonstrated that FO inhibited hydrogen peroxide (H2O2)-induced DNA damage and cytotoxicity through the rescue of mitochondrial function by blocking abnormal ROS accumulation. FO also prevented apoptosis by suppressing loss of mitochondrial membrane potential and cytosolic release of cytochrome c, decreasing the rate of Bax/Bcl-2 expression and reducing the activity of caspase-9 and caspase-3 in H2O2-stimulated MC3T3-E1 osteoblasts, suggesting that FO protected MC3T3-E1 osteoblasts from the induction of caspase dependent- and mitochondria-mediated apoptosis by oxidative stress. In addition, FO markedly promoted the activation of nuclear factor-erythroid-2-related factor 2 (Nrf2), which was associated with the enhanced expression of heme oxygenase-1 (HO-1). However, inhibiting the expression of HO-1 by artificially blocking the expression of Nrf2 using siRNA significantly eliminated the protective effect of FO, indicating that FO activates the Nrf2/HO-1 signaling pathway in MC3T3-E1 osteoblasts to protect against oxidative stress. Based on the present data, FO is thought to be useful as a potential therapeutic agent for the inhibition of oxidative stress in osteoblasts

Pharmacokinetics of a telmisartan, amlodipine and hydrochlorothiazide fixed-dose combination: A replicate crossover study in healthy Korean male subjects

Purpose: To compare the tolerability and pharmacokinetic profiles of telmisartan, amlodipine, and hydrochlorothiazide (HCTZ) in a fixed-dose combination (FDC, test product) with a co-administered telmisartan/amlodipine FDC and HCTZ in a single-entity tablet (reference product)Methods: This was a single-dose, randomized, open-label, replicate crossover study conducted in healthy male Korean volunteers aged 19 – 50 years. Fasting randomized subjects received a newly developed test product (telmisartan/ amlodipine/HCTZ, 80/10/25 mg) or two tablets of Twynsta® (40/5 mg) and one tablet of HCTZ (25 mg) as reference products. After a washout period, each group replicated the exposure of the other group.Results: The AUClast (h•ng/mL) geometric mean was 3,194.87 and 3,273.77 for the telmisartan test and reference products, respectively; 329.92 and 315.13 for the amlodipine test and reference products; 1,203.98 and 1,150.86 for the HCTZ test and reference products, respectively. The geometric mean of Cmax (ng/mL) was 543.04 and 497.81 for the telmisartan test and reference products, respectively; 7.74 and 7.34 for the amlodipine test and reference products; 218.71 and 184.39 for the HCTZ test and reference products, respectively. For telmisartan, the 90 % CI of GMRs of AUClast (h•ng/mL) and Cmax (ng/mL) were 0.9414 – 1.0496 and 1.0246 – 1.2792, respectively; the coefficient of variation (CV) of telmisartan Cmax was 41.96 %.Conclusion: A formulated FDC tablet containing a telmisartan/amlodipine/HCTZ combination (80/10/25mg) was bioequivalent to a co-administrated commercially available telmisartan/amlodipine combination and HCTZ tablets at equivalent concentrations.Keywords: Fixed-dose combination, Hypertension, Telmisartan, Amlodipine besylate, Hydrochlorothiazide, Pharmacokinetic

Oral Muscle Relaxant May Induce Immediate Allergic Reactions

Eperisone and afloqualone act by relaxing both skeletal and vascular smooth muscles to improve circulation and suppress pain reflex. These drugs are typically prescribed with non-steroidal anti-inflammatory drugs (NSAIDs) as painkillers. However, there have been no reports on serious adverse reactions to oral muscle relaxants; and this is the first report to describe three allergic reactions caused by eperisone and afloqualone. All three patients had histories of allergic reactions after oral intake of multiple painkillers, including oral muscle relaxants and NSAIDs, for chronic muscle pain. An open-label oral challenge test was performed with each drug to confirm which drugs caused the systemic reactions. All patients experienced the same reactions within one hour after oral intake of eperisone or afloqualone. The severity of these reactions ranged from laryngeal edema to hypotension. To confirm that the systemic reaction was caused by eperisone or afloqualone, skin prick testing and intradermal skin tests were performed with eperisone or afloqualone extract in vivo, and basophil activity tests were performed after stimulation with these drugs in vitro. In one patient with laryngeal edema, the intradermal test with afloqualone extract had a positive result, and CD63 expression levels on basophils increased in a dose-dependent manner by stimulation with afloqualone. We report three allergic reactions caused by oral muscle relaxants that might be mediated by non-immunoglobulin E-mediated responses. Since oral muscle relaxants such as eperisone and afloqualone are commonly prescribed for chronic muscle pain and can induce severe allergic reactions, we should prescribe them carefully

Lumbar plexopathy after radical nephrectomy -A case report-

Lumbar plexopathy is characterized by an abrupt onset of sensory disturbances, weakness, and loss of deep tendon reflexes of lower extremities. The various causes of lumbar plexopathy include trauma, infections, space-occupying lesion, vascular diseases, metabolic diseases, and the use of drugs such as heroin. Postoperative rhabdomyolysis occurs secondary to prolonged muscle compression due to surgical positioning. Herein, we report a case of lumbar plexopathy, complicating an injury to the paraspinal muscle and iliopsoas muscle that occurred in the flexed lateral decubitus position following radical nephrectomy