Invasive aspergillosis is a rare complication in patients with influenza infection. Several cases of invasive pulmonary aspergillosis accompanying influenza infections were reported during the influenza A/H1N1pdm 2009. We encountered a case of acute cerebral aspergillosis in a patient with influenza A/H1N1pdm 2009 infection. A 24-year-old man with uncontrolled diabetes was diagnosed with influenza A/H1N1pdm 2009 infection. Initial evaluation indicated methicillin-sensitive Staphylococcus aureus pneumonia and diabetic ketoacidosis along with influenza. During his hospital course, multiple new rim-enhancing mass lesions not evident in the initial evaluation developed in the fronto-parietal cortical and subcortical white matter and right cerebellum. Pathology and culture results confirmed the presence of Aspergillus fumigatus. Surgical drainage combined with a total of 18 weeks of antifungal therapy resulted in complete resolution of the infection. This case demonstrates that cerebral aspergillosis can present alongside influenza in patients with diabetes or those under intensive care. Clinical suspicion of invasive aspergillosis is required for a definite diagnosis and better prognosis in such cases.
Central nervous system; Invasive aspergillosis; Influenza; Brain abscess; Diabetes mellitus
Acute kidney injury (AKI) is frequently complicated by extra-renal multi-organ injury including intestinal and hepatic dysfunction. In this study, we hypothesized that a discrete intestinal source of pro-inflammatory mediators drives multi-organ injury in response to AKI. After induction of AKI in mice by renal ischemia-reperfusion or bilateral nephrectomy, small intestinal Paneth cells increased the synthesis and release of IL-17A in conjunction with severe intestinal apoptosis and inflammation. We also detected significantly increased IL-17A in portal and systemic circulation after AKI. Intestinal macrophages appear to transport released Paneth cell granule constituents induced by AKI, away from the base of the crypts into the liver. Genetic or pharmacologic depletion of Paneth cells decreased small intestinal IL-17A secretion and plasma IL-17A levels significantly and attenuated intestinal, hepatic, and renal injury after AKI. Similarly, portal delivery of IL-17A in macrophage depleted mice decreased markedly, and intestinal, hepatic, and renal injury following AKI was attenuated without affecting intestinal IL-17A generation. In conclusion, AKI induces IL-17A synthesis and secretion by Paneth cells to initiate intestinal and hepatic injury by hepatic and systemic delivery of IL-17A by macrophages. Modulation of Paneth cell dysregulation may have therapeutic implications by reducing systemic complications arising from AKI.
acute renal failure; apoptosis; cytokine; inflammation; ischemia reperfusion; nephrectomy
The aim of this study was to evaluate the surface properties and in vitro bioactivity to osteoblasts of magnesium and magnesium-hydroxyapatite coated titanium.
MATERIALS AND METHODS
Themagnesium (Mg) and magnesium-hydroxyapatite (Mg-HA) coatings on titanium (Ti) substrates were prepared by radio frequency (RF) and direct current (DC) magnetron sputtering.The samples were divided into non-coated smooth Ti (Ti-S group), Mg coatinggroup (Ti-Mg group), and Mg-HA coating group (Ti-MgHA group).The surface properties were evaluated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The surface roughness was evaluated by atomic force microscopy (AFM). Cell adhesion, cell proliferation and alkaline phosphatase (ALP) activity were evaluated using MC3T3-E1 cells. Reverse transcription polymerase chain reaction (RT-PCR) analysis was performed.
Cross-sectional SEM images showed that Mg and Mg-HA depositionson titanium substrates were performed successfully. The surface roughness appeared to be similaramong the three groups. Ti-MgHA and Ti-Mg group had improved cellular responses with regard to the proliferation, alkaline phosphatase (ALP) activity, and bone-associated markers, such as bone sialoprotein (BSP) and osteocalcin (OCN) mRNA compared to those of Ti-S group. However, the differences between Ti-Mg group and Ti-MgHA group were not significant, in spite of the tendency of higher proliferation, ALP activity and BSP expression in Ti-MgHA group.
Mg and Mg-HAcoatings could stimulate the differentiation into osteoblastic MC3T3-E1 cells, potentially contributing to rapid osseointegration.
Biocompatible materials; Surface-Coated materials; Surface properties; Alkaline phosphatase; Bone sialoprotein; Osteocalcin
The nuclear DNA binding protein high mobility group box 1 (HMGB1) has recently been suggested to act as a late mediator of septic shock. The effect of ((S)-6,7-dihydroxy-1-(4-hydroxynaphthylmethyl)-1,2,3,4-tetrahydroisoquinoline alkaloid, also known as THI-56, in an experimental model of sepsis was investigated. THI-56 exhibited potent anti-inflammatory properties in response to LPS in RAW 264.7 cells. In particular, THI-56 significantly inhibited the expression of inducible nitric oxide synthase (iNOS) and the release of HMGB1 in activated macrophages. THI-56 activated NE-F2-regulated factor 2 (Nrf-2)/heme oxygenase 1 (HO-1). The specific knockdown of the HO-1 gene by HO-1 siRNA significantly reversed the inhibitory effects of THI-56 on iNOS expression and HMGB1 release in LPS-stimulated macrophages. Importantly, THI-56 administration protected animals from death induced by either a lethal dose of LPS or cecal ligation and puncture (CLP). Furthermore, the ALT, AST, BUN, creatinine, and HMGB1 levels in the blood were significantly increased in CLP-induced septic mice, and the administration of THI-56 reduced these levels in a concentration-dependent and zinc protoporphyrin IX (ZnPPIX)-sensitive manner. In addition, the administration of THI-56 significantly ameliorated not only lung damage but also macrophage infiltration in the livers of CLP-induced septic mice, and these effects were also abrogated in the presence of ZnPPIX. Thus, we conclude that THI-56 significantly attenuates the proinflammatory response induced by LPS and reduces organ damage in a CLP-induced sepsis model through the upregulation of Nrf-2/HO-1.
Renal ischemia–reperfusion injury (IRI) is a major cause of acute kidney injury and often leads to multi-organ dysfunction and systemic inflammation. Volatile anesthetics have potent antiinflammatory effects and we aimed to determine whether the representative volatile anesthetic isoflurane protects against acute kidney injury-induced liver and intestinal injury and the mechanisms involved in this protection.
Mice were anesthetized with pentobarbital and subjected to 30 min of left renal ischemia after right nephrectomy followed by exposure to 4 h of equi-anesthetic doses of pentobarbital or isoflurane. Five hrs after renal IRI, plasma creatinine and alanine aminotransferase were measured. Liver and intestine tissues were analyzed for pro-inflammatory mRNAs, histology, sphingosine kinase-1 (SK1) immunoblotting, SK1 activity, and sphingosine-1-phosphate levels.
Renal IRI with pentobarbital led to severe renal, hepatic, and intestinal injury with focused peri-portal hepatocyte vacuolization, small intestinal apoptosis and pro-inflammatory mRNA upregulation. Isoflurane protected against renal IRI and reduced hepatic and intestinal injury via induction of small intestinal crypt SK1 mRNA, protein and enzyme activity and increase in S1P. We confirmed the importance of SK1 as mice treated with a selective SK inhibitor (SKI-II) or mice deficient in SK1 enzyme were not protected against hepatic and intestinal dysfunction with isoflurane.
Taken together, we demonstrate that isoflurane protects against multi-organ injury after renal IRI via induction of the SK1/sphingosine-1-phosphate pathway. Our findings may help to unravel the cellular signaling pathways of volatile anesthetic-mediated hepatic and intestinal protection and lead to new therapeutic applications of volatile anesthetics during the perioperative period.
Renal ischemia reperfusion injury is a major cause of acute kidney injury. We previously found that renal A1 adenosine receptor (A1AR) activation attenuated multiple cell death pathways including necrosis, apoptosis and inflammation. Here, we tested whether induction of cytoprotective sphingosine kinase (SK)-1 and sphingosine-1 phosphate (S1P) synthesis might be the mechanism of protection. A selective A1AR agonist (CCPA) increased the synthesis of S1P and selectively induced SK-1 in mouse kidney and HK-2 cells. This agonist failed to protect SK1-knockout but protected SK2-knockout mice against renal ischemia reperfusion injury indicating a critical role of SK1 in A1AR-mediated renal protection. Inhibition of SK prevented A1AR-mediated defense against necrosis and apoptosis in HK-2 cells. A selective S1P1R antagonist (W146) and global in vivo gene knockdown of S1P1Rs with small interfering RNA completely abolished the renal protection provided by CCPA. Mice selectively deficient in renal proximal tubule S1P1Rs (S1P1Rflox/flox PEPCKCre/−) were not protected against renal ischemia reperfusion injury by CCPA. Mechanistically, CCPA increased nuclear translocation of hypoxia inducible factor-1α in HK-2 cells and selective hypoxia inducible factor-1α inhibition blocked A1AR-mediated induction of SK1. Thus, proximal tubule SK-1 has a critical role in A1AR-mediated protection against renal ischemia reperfusion injury.
apoptosis; hypoxia inducible factor-1α; inflammation; necrosis; sphingosine 1-phosphate
This study examined volatile anesthetic-mediated protection against intestinal ischemia-reperfusion injury (IRI).
Intestinal IRI is a devastating complication in the perioperative period leading to systemic inflammation and multi-organ dysfunction. Volatile anesthetics, including isoflurane, have anti-inflammatory effects. We aimed to determine whether isoflurane, given after intestinal ischemia, protects against intestinal IRI and the mechanisms involved in this protection.
After IACUC approval, mice were anesthetized with pentobarbital and subjected to 30 min of superior mesenteric artery ischemia, followed by 4 hrs of equianesthetic doses of pentobarbital or isoflurane. Five hrs after reperfusion, small intestine tissues were analyzed for morphological injury, apoptosis, neutrophil infiltration, pro-inflammatory mRNAs, and TGF-β1 levels. We also assessed hepatic and renal injury after intestinal IRI.
Intestinal IRI with pentobarbital led to significant small intestinal dysfunction with increased mucosal injury, TUNEL-positive cells, neutrophil infiltration, and pro-inflammatory mRNAs as well as elevated plasma alanine aminotransferase and creatinine levels. Isoflurane exposure after IRI led to significant attenuation of intestinal, hepatic, and renal injuries. Furthermore, the protective effects of isoflurane were abolished by treatment with a TGF-β1 neutralizing antibody prior to induction of IRI. Finally, isoflurane exposure led to increased TGF-β1 levels in intestinal epithelial cells and in plasma.
Our findings demonstrate that isoflurane postconditioning protects against small intestinal injury as well as hepatic and renal dysfunction after severe intestinal IRI via induction of intestinal epithelial TGF-β1. Our findings support therapeutic applications of volatile anesthetics during the intraoperative as well as postoperative periods and imply an important role of TGF-β1 signaling in modulating multi-organ injury.
Korea is a low prevalence country for human immunodeficiency virus (HIV) infection and has an intermediate tuberculosis (TB) burden. We previously reported that the incidence of TB in HIV-infected patients was 9.6 cases per 100 person-years (P-Y) between 1988 and 1997. The aims of the present study were to measure any change in incidence from the previous study, and to identify risk factors for TB in HIV-infected patients. We reviewed all medical records of HIV-infected patients who were followed-up in one tertiary hospital between 1998 and 2010. Over the total observation period of 5858.33 P-Y, TB developed in 70 patients (1.19 cases per 100 P-Y; 95% confidence interval [CI], 0.91-1.47 cases per 100 P-Y). Based on Poisson regression, one risk factor associated with TB was an initial CD4+ cell count below 200 cells/µL (relative risk, 2.34; 95% CI, 1.47-3.73). Mean CD4+ cell counts of pulmonary, extrapulmonary, and both pulmonary and extrapulmonary TB were 179.8 cells/µL, 138.3 cells/µL, and 114.2 cells/µL, respectively (P = 0.55). In conclusion, the incidence of TB in HIV-infected patients has decreased since the previous study. An initial CD4+ cell count below 200 cells/µL is an independent risk factor for development of TB in HIV-infected patients.
Tuberculosis; Incidence; Risk Factors; HIV
ERK5, a member of the mitogen activated protein kinase, expressed in the kidneys was smaller (~80 kDa) in apparent molecular mass compared to other organs (~120 kDa). A blocking peptide experiment confirmed that the ~80 kDa detected on Western blots was a specific band detected by the anti-ERK5 antibody. Expression of the known ERK5 variants ERK5a, b, c, and T confirmed that none of the known splice variants encoded for the renal-specific ~80 kDa protein. However, RT-PCR with primers targeting the potential splice sites did not reveal a novel transcript in the kidney. The smaller molecular mass of the kidney-specific ERK5-immunoreactive protein suggested that this cyto-protective molecule may not be fully functional in the kidneys. Lentivirus-mediated in vivo overexpression of full length ERK5 in the mouse kidneys provided protection against renal IR injury. The identity of the renal-specific ~80 kDa ERK5 remains unknown but a better understanding of the ERK5 expression and post-translational processing in the kidneys may reveal a novel strategy for renal protection.
MAPK; ERK5; Western blot; mobility shift; viral transduction; IR injury
There is little information about the effectiveness of ciprofloxacin in regions where ciprofloxacin-resistant Escherichia coli is prevalent. This study was conducted to evaluate whether ciprofloxacin is effective as the initial empirical antibiotic for treatment of uncomplicated acute pyelonephritis (APN) due to ciprofloxacin-resistant E. coli. A total of 255 women with clinical diagnoses of uncomplicated APN due to E. coli were enrolled in the emergency department between March 2005 and December 2008. All enrolled patients were initially treated with ciprofloxacin. Patients were followed up 4 to 7 days after the start of therapy and 14 to 21 days after its completion. At the first follow-up visit, ciprofloxacin was changed to the appropriate antibiotic when necessary, depending on the antibiotic susceptibility results. Not only improvement of symptoms and signs but also microbiologic eradication was assessed at each visit. Fifteen percent (39/255) of the E. coli isolates were resistant to ciprofloxacin. There was no statistically significant difference between the clinical cure rates of the ciprofloxacin-susceptible group and the ciprofloxacin-resistant group at the first follow-up (87.0% versus 76.9%, P = 0.135) or the second follow-up (98.6% versus 94.9%, P = 0.177). However, there was a lower microbiologic cure rate in the ciprofloxacin-resistant group than in the ciprofloxacin-susceptible group (92.4% versus 41.7%, P = 0.000) at the first follow-up visit. No complications occurred in the ciprofloxacin-resistant group during the follow-up period. Our findings indicate that ciprofloxacin is an appropriate choice for empirical therapy of uncomplicated APN and has no serious adverse outcomes, if it is tailored appropriately, even for women infected with ciprofloxacin-resistant E. coli.
We evaluated risk factors for neutropenic fever and febrile prolonged neutropenia during vincristine-including chemotherapy to treat HIV-related lymphoma to investigate whether protease inhibitor (PI) treatment is associated with infectious complications due to drug interactions with chemotherapeutic agents. We included all HIV patients who received chemotherapy including vincristine for lymphoma at a single referral center in 1999-2010. Neutropenic fever was defined as absolute neutrophil count < 500 cells/µL with body temperature over 38℃; and prolonged neutropenia was defined if it persisted over 7 days. CODOX-M/IVAC and Stanford regimens were considered high-risk regimens for prolonged neutropenia. We analyzed 48 cycles of chemotherapy in 17 HIV patients with lymphoma. There were 22 neutropenic fever and 12 febrile prolonged neutropenia events. In multivariate analysis, neutropenic fever was associated with old age and low CD4 cell count, but not with PI use or ritonavir-boosted PI use. Low CD4 cell count and high-risk regimens were associated with febrile prolonged neutropenia. Neutropenic fever and febrile prolonged neutropenia is associated with old age, low CD4 cell count, and high-risk regimens, but not PI use, in HIV patients undergoing chemotherapy including vincristine for lymphoma.
Human Immunodeficiency Virus; Lymphoma; Neutropenia
We prospectively evaluated severity predictors in terms of host, microorganism, and treatment factors in 153 eschar-positive scrub typhus patients. Severity was assessed with the Acute Physiology and Chronic Health Evaluation (APACHE) II score (< 10 versus ≥ 10) and predefined criteria of severe complications. Genotypes of Orientia tsutsugamushi were determined. Independent risk factors for severity (APACHE II score ≥ 10) were old age, diabetes mellitus, serum osteopontin > 100 ng/mL, and a group of underlying diseases (congestive heart failure, cerebrovascular disease, chronic liver disease, bronchial asthma, and chronic obstructive lung diseases). Anemia (≤ 10 g/dL) and C-reactive protein > 10 mg/dL were indicators of current severity. Neither the delay in antibiotics administration nor strain types (Boryong, Taguchi, or Kanda/Kawasaki) contributed to the severity. The risk factors for severe complications were similar. Serum osteopontin > 100 ng/mL had a negative predictive value of 96% for severe complications. This marker can be used to rule out severe disease status.
We retrospectively reviewed medical records to identify the factors that affect the results of culture in patients with pyogenic vertebral osteomyelitis. In multivariate analysis, the presence of paravertebral abscess was associated with positive results of microbiologic culture. Prior antibiotic exposure, especially of longer duration, was strongly associated with negative results.
Hepatic ischemia and reperfusion (IR) injury is a major clinical problem that leads to frequent extra-hepatic complications including intestinal dysfunction and acute kidney injury (AKI). In this study, we aimed to determine the mechanisms of hepatic IR-induced extra-hepatic organ dysfunction. Mice subjected to 60 min of hepatic IR not only developed severe hepatic injury but also developed significant AKI and small intestinal injury. Hepatic IR induced small intestinal Paneth cell degranulation and increased IL-17A levels in portal vein plasma and small intestine. We also detected increased levels of IL-17A mRNA and protein in Paneth cells after hepatic IR with laser capture dissection. IL-17A neutralizing antibody treatment or genetic deletion of either IL-17A or IL-17A receptors significantly protected against hepatic IR-induced acute liver, kidney and intestinal injury. Leukocyte IL-17A does not contribute to organ injury as infusion of wild type splenocytes failed to exacerbate liver and kidney injury in IL-17A deficient mice after hepatic IR. Depletion of Paneth cell numbers by pharmacological (with dithizone) or genetic intervention (SOX9 flox/flox Villin cre+/− mice) significantly attenuated intestinal, hepatic, and renal injury following liver IR. Finally, depletion of Paneth cell numbers significantly decreased small intestinal IL-17A release and plasma IL-17A levels after liver IR. Taken together, the results show that Paneth cell derived IL-17A plays a critical role in hepatic IR injury and extra-hepatic organ dysfunction. Modulation of Paneth cell dysregulation may have therapeutic implications by reducing systemic complications arising from hepatic IR.
apoptosis; dithizone; inflammation; kidney; liver; necrosis; small intestine
About 20% of methicillin-susceptible Staphylococcus aureus (MSSA) isolates have a substantial inoculum effect with cefazolin, suggesting that cefazolin treatment may be associated with clinical failure for serious MSSA infections. There are no well-matched controlled studies comparing cefazolin with nafcillin for the treatment of MSSA bacteremia. A retrospective propensity-score-matched case-control study was performed from 2004 to 2009 in a tertiary care hospital where nafcillin was unavailable from August 2004 to August 2006. The cefazolin group (n = 49) included MSSA-bacteremic patients treated with cefazolin during the period of nafcillin unavailability, while the nafcillin group (n = 84) comprised those treated with nafcillin. Treatment failure was defined as a composite outcome of a change of antibiotics due to clinical failure, relapse, and mortality. Of 133 patients, 41 patients from each group were matched by propensity scores. There were no significant differences in baseline characteristics between the matched groups. The treatment failure rates were not significantly different at 4 or 12 weeks (10% [4/41] versus 10% [4/41] at 4 weeks [P > 0.99] and 15% [6/41] versus 15% [6/41] at 12 weeks [P > 0.99]). Cefazolin treatment was interrupted less frequently than nafcillin treatment due to drug adverse events (0% versus 17%; P = 0.02). Cefazolin had clinical efficacy similar to that of nafcillin and was more tolerable than nafcillin for the treatment of MSSA bacteremia.
The potential for human disease treatment using human pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells (iPSCs), also carries the risk of added genomic instability. Genomic instability is most often linked to DNA repair deficiencies, which indicates that screening/characterization of possible repair deficiencies in pluripotent human stem cells should be a necessary step prior to their clinical and research use. In this study, a comparison of DNA repair pathways in pluripotent cells, as compared to those in non-pluripotent cells, demonstrated that DNA repair capacities of pluripotent cell lines were more heterogeneous than those of differentiated lines examined and were generally greater. Although pluripotent cells had high DNA repair capacities for nucleotide excision repair, we show that ultraviolet radiation at low fluxes induced an apoptotic response in these cells, while differentiated cells lacked response to this stimulus, and note that pluripotent cells had a similar apoptotic response to alkylating agent damage. This sensitivity of pluripotent cells to damage is notable since viable pluripotent cells exhibit less ultraviolet light-induced DNA damage than do differentiated cells that receive the same flux. In addition, the importance of screening pluripotent cells for DNA repair defects was highlighted by an iPSC line that demonstrated a normal spectral karyotype, but showed both microsatellite instability and reduced DNA repair capacities in three out of four DNA repair pathways examined. Together, these results demonstrate a need to evaluate DNA repair capacities in pluripotent cell lines, in order to characterize their genomic stability, prior to their pre-clinical and clinical use.
Therapeutic effects of GCSB-5 on osteoarthritis were measured by the amount of glycosaminoglycan in rabbit articular cartilage explants in vitro, in experimental osteoarthritis induced by intra-articular injection of monoiodoacetate in rats in vivo. GCSB-5 was orally administered for 28 days. In vitro, GCSB-5 inhibited proteoglycan degradation. GCSB-5 significantly suppressed the histological changes in monoiodoacetate-induced osteoarthritis. Matrix metalloproteinase (MMP) activity, as well as, the levels of serum tumor necrosis factor-α, cyclooxygenase-2, inducible nitric oxide synthase protein, and mRNA expressions were attenuated by GCSB-5, whereas the level of interleukin-10 was potentiated. By GCSB-5, the level of nuclear factor-κB p65 protein expression was significantly attenuated but, on the other hand, the level of inhibitor of κB-α protein expression was increased. These results indicate that GCSB-5 is a potential therapeutic agent for the protection of articular cartilage against progression of osteoarthritis through inhibition of MMPs activity, inflammatory mediators, and NF-κB activation.
Endothelial dysfunction is a major clinical problem affecting virtually every patient requiring critical care. Volatile anesthetics are frequently used during the perioperative period and protect the heart and kidney against ischemia and reperfusion injury. We aimed to determine whether isoflurane, the most commonly used volatile anesthetic in the USA, protects against endothelial apoptosis and necrosis and the mechanisms involved in this protection. Human endothelial EA.hy926 cells were pretreated with isoflurane or carrier gas (95% room air + 5% CO2) then subjected to apoptosis with tumor necrosis factor-α or to necrosis with hydrogen peroxide. DNA laddering and in situ Terminal Deoxynucleotidyl Transferase Biotin-dUTP Nick-End Labeling (TUNEL) staining determined EA.hy926 cell apoptosis and percent LDH released determined necrosis. We also determined whether isoflurane modulates the expression and activity of sphingosine kinase-1 (SK1) and induces the phosphorylation of extracellular signal regulated kinase (ERK MAPK) as both enzymes are known to protect against cell death. Isoflurane pretreatment significantly decreased apoptosis in EA.hy926 cells as evidenced by reduced TUNEL staining and DNA laddering without affecting necrosis. Mechanistically, isoflurane induces the phosphorylation of ERK MAPK and increased SK1 expression and activity in EA.hy926 cells. Finally, selective blockade of SK1 (with SKI-II) or S1P1 receptor (with W146) abolished the anti-apoptotic effects of isoflurane. Taken together, we demonstrate that isoflurane, in addition to its potent analgesic and anesthetic properties, protects against endothelial apoptosis most likely via SK1 and ERK MAPK activation. Our findings have significant clinical implication for protection of endothelial cells during the perioperative period and patients requiring critical care.
EA.hy926; sphingosine kinase; extracellular signal-regulated kinase; necrosis; volatile anesthetic
Repeated exposure to methamphetamine (METH) can cause not only neurotoxicity but also addiction. Behavioral sensitization is widely used as an animal model for the study of drug addiction. We previously reported that the μ-opioid receptor knockout mice were resistant to METH-induced behavioral sensitization but the mechanism is unknown.
The present study determined whether resistance of the μ-opioid receptor (μ-OR) knockout mice to behavioral sensitization is due to differential expression of the stimulatory G protein α subunit (Gαs) or regulators of G-protein signaling (RGS) coupled to the dopamine D1 receptor. Mice received daily intraperitoneal injections of saline or METH (10 mg/kg) for 7 consecutive days to induce sensitization. On day 11(following 4 abstinent days), mice were either given a test dose of METH (10 mg/kg) for behavioral testing or sacrificed for neurochemical assays without additional METH treatment.
METH challenge-induced stereotyped behaviors were significantly reduced in the μ-opioid receptor knockout mice when compared with those in wild-type mice. Neurochemical assays indicated that there is a decrease in dopamine D1 receptor ligand binding and an increase in the expression of RGS4 mRNA in the striatum of METH-treated μ-opioid receptor knockout mice but not of METH-treated wild-type mice. METH treatment had no effect on the expression of Gαs and RGS2 mRNA in the striatum of either strain of mice.
These results indicate that down-regulation of the expression of the dopamine D1 receptor and up-regulation of RGS4 mRNA expression in the striatum may contribute to the reduced response to METH-induced stereotypy behavior in μ-opioid receptor knockout mice. Our results highlight the interactions of the μ-opioid receptor system to METH-induced behavioral responses by influencing the expression of RGS of dopamine D1 receptors.
Amphetamine; μ-opioid receptor; addiction; dopamine receptors
Information about the genotype of varicella-zoster virus (VZV) is useful to monitor outbreaks of vaccine strains. However, in South Korea, where varicella vaccine was introduced in 1988, there are limited data about the genotype of VZV. VZV was isolated from vesicular lesions of patients with herpes zoster or varicella in South Korea between January 2007 and June 2009. DNAs were purified from single-passage isolates. The genotype was determined by sequence analysis of open reading frame (ORF) 22. The PstI restriction enzyme site in ORF 38 and the BglI restriction enzyme site in ORF 54 were evaluated by restriction enzyme analysis. Forty-four patients with herpes zoster and nine patients with varicella were enrolled. The median age of patients with herpes zoster was 59.5 (range, 10 to 77) years, and the median age of patients with varicella was 8 (range, 6 to 9) years. In sequence analysis of ORF 22, all isolates were genotype J, irrespective of the age group. In restriction enzyme analysis, 51 of 54 (94.3%) isolates contained a PstI site in ORF 38, and all isolates contained a BglI site in ORF 54. Our data suggest that genotype J has been circulating since the 1940s in South Korea.
This study was performed to determine the nationwide antigenic diversity of Orientia tsutsugamushi in South Korea. Sequence analysis was performed around variable domains I and II of a 56-kDa protein-encoding gene. We used eschar to overcome the disadvantages of conventional serotyping. The serological passive hemagglutination assay (PHA) was assessed based on the genotyping results. We analyzed 153 isolates from scrub typhus patients in major endemic areas and found that Boryong was the major strain (68.6%). New strains were also identified: Taguchi (19.6%), Kanda/Kawasaki (9.2%), and UAP7 (1.3%). PHA yielded significantly fewer positive results among Kawasaki strains (P < 0.001), which are not included in the PHA antigen panel. In South Korea, Boryong was still the predominant strain, but the sequence analysis identified new changes in minor strains (30.1%). This antigenic drift had a negative effect on the PHA results. Periodic surveillance of the contemporary strains using sequence analysis is needed.