Perianal Tick-Bite Lesion Caused by a Fully Engorged Female Amblyomma testudinarium

A perianal tick and the surrounding skin were surgically excised from a 73-year-old man residing in a southwestern costal area of the Korean Peninsula. Microscopically a deep penetrating lesion was formed beneath the attachment site. Dense and mixed inflammatory cell infiltrations occurred in the dermis and subcutaneous tissues around the feeding lesion. Amorphous eosinophilic cement was abundant in the center of the lesion. The tick had Y-shaped anal groove, long mouthparts, ornate scutum, comma-shaped spiracular plate, distinct eyes, and fastoons. It was morphologically identified as a fully engorged female Amblyomma testudinarium. This is the third human case of Amblyomma tick infection in Korea.

Midazolam protects B35 neuroblastoma cells through Akt-phosphorylation in reactive oxygen species derived cellular injury / 대한마취과학회지

BACKGROUND: Soman, a potent irreversible acetylcholinesterase (AChE) inhibitor, induces delayed neuronal injury by reactive oxygen species (ROS). Midazolam is used in patients with pathologic effects of oxidative stresses such as infection, hemodynamic instability and hypoxia. We investigated whether midazolam protects the Central Nervous System (CNS) from soman intoxication. The present study was performed to determine whether midazolam protects B35 cells from ROS stress for the purpose of exploring an application of midazolam to soman intoxication. METHODS: Glucose oxidase (GOX) induced ROS stress was used in a B35 neuroblastoma cell model of ROS induced neuronal injury. To investigate the effect of midazolam on cell viability, LDH assays and fluorescence activated cell sorting (FACS) analysis was performed. Western blotting was used for evaluating whether Akt-phosphorylation is involved in cell-protective effects of midazolam. RESULTS: GOX derived ROS injury decreased cell viability about 1.6-2 times compared to control; midazolam treatment (5 and 10 microg/ml) dose-dependently increased cell viability during ROS injury. On western blots, Akt-phosphorylation was induced during pretreatment with midazolam; it was diminished during co-treatment with LY-294002, an inhibitor of Akt-phosphorylation. FACS analysis confirmed that the cell protective effect of midazolam is mediated by an anti-apoptotic effect. GOX-induced apoptosis was inhibited by midazolam and the finding was diminished by LY-294002. CONCLUSIONS: Midazolam protects neuronal cells from GOX-induced ROS injury; this effect is mediated by an anti-apoptotic effect through Akt-phosphorylation. This shows that midazolam may be useful in soman intoxication.

Distribution of Genomic Species and Antimicrobial Susceptibility in Acinetobacters Isolated from Gangjin Bay, Korea

A total of 90 Acinetobacter isolates from freshwater and seawater in Gangjin Bay of Korea was investigated for the distribution of genomic species, antimicrobial resistance patterns and clonal relatedness. By amplified ribosomal DNA restriction analysis, eighty-nine Acinetobacter isolates were classified into 11 Acinetobacter genomic species. A. johnsonii (n=23) was the most prevalent, followed by A. baumannii (n=13), A. calcoaceticus (n=13), Acinetobacter genomic species 11 (n=10), A. phenon 6/ct13TU (n=9), A. junii (n=5), A. venetianus (n=5), Acinetobacter genomic species 17 (n=4), 14BJ (n=3), A. phenon 10/1271 (n=2), Acinetobacter genomic species 3 (n=1), and ungrouped (n=1). The majority of Acinetobacter genomic species were isolated from the site A and B, and some known nosocomial pathogens in the clinical environment were observed among them. Of the 11 antimicrobial drugs tested, several A. johnsonii isolates exhibited high-frequency resistance to a wide variety of antimicrobial agents, including ampicillin-sulbactam, piperacillin, ceftazidime, cefotaxime, and sulfamethoxazole (p < 0.001). Some Acinetobacter genomic species were resistant to currently used antibiotics but all isolates were susceptible to imipenem, amikacin, and tetracycline. Based on the results of antimicrobial resistance pattern and phylogenetic analysis, 23 A. johnsonii isolates were classified into 19 pulsotypes. In conclusion, there was a significant difference in the distribution of Acinetobacter species between freshwater and seawater. Predominance of A. johnsonii strains was probably due to their ability to proliferate in the contaminated aquatic environment originated from local geographic features. Therefore, the waste effluent from animals and humans plays an important role in the distribution of Acinetobacter species in aquatic environment.

YS 49, a Synthetic Isoquinoline Alkaloid, Protects Sheep Pulmonary Artery Endothelial Cells from tert-butylhydroperoxide-mediated Cytotoxicity

Endothelium, particularly pulmonary endothelium, is predisposed to injury by reactive oxygen species (ROS) and their derivatives. Heme oxygenase (HO) has been demonstrated to provide cytoprotective effects in models of oxidant-induced cellular and tissue injuries. In the present study, we investigated the effects of YS 49 against oxidant [tert-butylhydroperoxide (TBH) ]-induced injury using cultured sheep pulmonary artery endothelial cells (SPAECs). The viability of SPAECs was determined by quantifying reduction of a fluorogenic indicator Alamar blue. We found that TBH decreased cell viability in a time- and concentration-dependent manner. YS 49 concentration- and time-dependently increased HO-1 induction on SPAECs. As expected, YS 49 significantly decreased the TBH-induced cellular injury. In the presence of zinc protophorphyrin, HO-1 inhibitor, effect of YS 49 was significantly inhibited, indicating that HO-1 plays a protective role for YS 49. Furthermore, YS 49 showed free radical scavenging activity as evidenced by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and inhibition of lipid peroxidation. However, YS 49 did not inhibit apoptosis induced by lipopolysaccharide (LPS) in SPAECs. Taken together, HO-1 induction along with strong antioxidant action of YS 49 may be responsible for inhibition of TBH-induced injury in SPAECs.

Comparison of inodilator effect of higenamine, YS49, YS51, tetra-hydroisoquinoline analogs, and dobutamine in the rat

Tetrahydroisoquinoline (THI) alkaloids can be considered as cyclized derivatives of simple phenylethylamines. Many of them, especially with 6,7-disubstitution, demonstrate a relatively high affinity for catecholamines. Present study examines the pharmacological action of limited series of THI, using rats' isolated atria and aorta. In addition, a (3H) prazosin displacement binding study with THI compounds was performed, using rat brain homogenates to investigate whether these probes have a-adrenoceptor affinity. We also compared the vascular relaxation potency of these probes with dobutamine. YS 49, YS 51, higenamine and dobutamine, concentration-dependently, relaxed endothelium-denuded rat thoracic aorta precontracted with phenylephrine (PE, 0.1 micrometer) in which pEC50 were 5.56-0.32 and 5.55+/-0.21, 5.99+/- 1.16 and 5.57+/-0.34, respectively. These probes except higenamine also relaxed KCl (65.4 mM)-contracted aorta. In isolated rat atria, all THIs and dobutamine increased heart rate and contractile force. In the presence of propranolol, the concentration response curves of YS 49 and YS 51 shifted to the right and resulted in pA2 values of 8.07+/-0.84 and 7.93+/-0.11, respectively. The slope of each compound was not deviated from unity, indicating that these chemicals are highly competitive at the cardiac beta-adrenoceptors. YS 49 YS 51, and higenamine showed alpha-adrenoceptor affinity in rat brain, in which the dissociation constant (Ki) was 2.75, 2.81, and 1.02 micrometer, respectively. It is concluded, therefore, that THI alkaloids have weak affinity to alpha1-adrenoceptors in rat aorta and brain, respectively, while these probes show relatively high affinity for cardiac beta-adrenoceptors. Thus, these chemicals may be useful in the treatment of congestive heart failure.

Pharmacological characterization of synthetic tetrahydroisoquinoline alkaloids, YS 51 and YS 55, on the cardiovascular system

Tetrahydroisoquinoline (THI) alkaloids can be considered as cyclized derivatives of simple phenylethylamines, and many of them, especially with 6,7-disubstitution, demonstrate relatively high affinity for catecholamines. Two -OH groups at 6 and 7 positions are supposed to be essential to exert beta-receptor activities. However, it is not clear whether -OH at 6,7 substitution of THIs also shows alpha-adrenoceptor activities. In the present study, we investigated whether -OH or -OCH3 substitutions of 6,7 position of THIs differently affect the alpha1-adrenoceptor affinity. We synthesized two 1-naphthylmethyl THI alkaloids, 1-beta-naphthylmethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline HBr (YS 51) and 1-beta-naphthylmethyl-6, 7-dimethoxy-1,2,3,4-tetrahydroisoquinoline HCl (YS 55), and their pharmacological actions on alpha1-adrenoceptor were compared. YS 51 and YS 55, concentration-dependently relaxed endothelium-denuded rat thoracic aorta precontracted with phenylephrine (PE, 0.1 micrometer) in which pEC50 were 5.89+0.21 and 5.93+ 0.19, respectively. Propranolol (30 nM) did not affect the relaxation-response curves to YS 51 and YS 55. Concentration-response curves to PE were shifted to right by the pretreatment with YS 51 or YS 55. The pA2 values of YS 51 and YS 55 showed 6.05 + 0.24 and 5.88 + 0.16, respectively. Both probes relaxed KCl (65.4 mM)-contacted aorta and inhibited CaCl2-induced contraction of PE-stimulated endothelium-denuded rat thoracic aorta in Ca2+-free solutions. In isolated guinea pig papillary muscle, 1 and 10 micrometer YS 51 increased contractile force about 4- and 8- fold over the control, respectively, along with the concentration-dependent increment of cytosolic Ca2+ ions. While, 10 micrometer YS 55 reduced the contractile force about 50 % over the control and lowered the cytosolic Ca2+ level, in rat brain homogenates, YS 51 and YS 55 displaced (3H)prazosin binding competitively with Ki 0.15 and 0.12 micrometer, respectively. However, both probes were ineffective on (3H)nitrendipine binding. Therefore, it is concluded that two synthetic naphthylmethyl-THI alkaloids have considerable affinity to alpha1-adrenenoceptors in rat aorta and brain.