The rocky road to freedom: number of countries transited during defection and risk of metabolic syndrome among North Korean Refugees in South Korea

OBJECTIVES

North Korean Refugees (NKRs) undergo defection, and this has been shown to impact their current health status in South Korea. However, little is understood about how the defection process is related to metabolic syndrome (MetS). This study regarded the defection process to be a quasi-measurement of traumatic experience and investigated whether defection was a risk factor for MetS among NKRs living in South Korea.

STUDY DESIGN

This cross-sectional study obtained data from the Korea University Anam Hospital in Seoul. NKRs (N = 847) voluntarily completed questionnaires and underwent at least one medical examination between October 2008 and July 2021.

METHODS

Multivariable logistic regression models were used to evaluate whether the number of countries transited by NKRs was associated with MetS by controlling for covariates.

RESULTS

The prevalence of MetS among male and female NKRs in South Korea was 12.3% and 13.3%, respectively. The highest prevalence of MetS (33.4%) was among NKRs who had transited two countries. The number of months in transit countries (mean: 49.9 ± 51.7) and period of residence in South Korea (mean: 40.9 ± 40.9 months) were also considered. NKRs who transited three countries had a higher probability of MetS (odds ratio [OR] 2.660, 95% confidence interval [CI] 1.161-6.097) than those who travelled directly to South Korea. NKRs who transited three countries and had only resided in South Korea for a short period had a higher probability of MetS (OR 3.424, 95% CI 1.149-10.208) than those who have lived in South Korea for a longer period.

CONCLUSIONS

Considering the social vulnerability of NKRs and consequential health problems, there is an urgent need for appropriate support from the government and society.

Antidepressant medication and risk of cardiovascular disease in posttraumatic stress disorder patients: application of marginal structural models in Korean National Health Insurance Database

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): - National Research Foundation of Korea (NRF) grant funded by the Ministry of Science and ICT

Introduction

Previous evidence on antidepressant medication and cardiovascular disease (CVD) in posttraumatic stress disorder (PTSD) patients is mixed. We evaluated associations between antidepressant medication and CVD by applying marginal structural model.

Methods

We gathered medical utilization records of 27,170 patients diagnosed with PTSD in years 2004 - 2018 without prior CVD diagnosis from Korean National Health Insurance Database (NHID). PTSD and CVD were characterized in correspondence of ICD-10 diagnostic codes. We acquired information on antidepressant use from medical utilization records and categorized by medication category: selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs) and tricyclic antidepressants (TCAs). Discrete-time survival analysis with marginal structural inverse probability weighting was used to test association between antidepressants and CVDs and were compared to results from traditional time-fixed model and simple time-varying model. We calculated cumulative daily defined doses (DDDs) of each antidepressant categories and conducted polynomial splining to test dose response.

Results

SSRI use was associated with acute coronary syndrome (hazard ratio [HR] 1.53, 95% confidence interval [CI] 1.26 - 1.86) and ischemic stroke (HR 1.33, 95% CI 1.08 - 1.63). SNRI use was associated with acute coronary syndrome (HR 1.52, 95% CI 1.09 - 2.12). TCA use was associated with acute coronary syndrome (HR 1.54, 1.21 - 1.96) and ischemic stroke (HR 1.34, 1.06 - 1.70). Polynomial spline showed positive dose-response in association between antidepressant use and CVD.

Conclusion

Antidepressant use is causally associated with CVD in patients with PTSD. Higher cumulative DDD of antidepressant increases the risk of CVD.

Does serum vitamin D level affect the association between cardiovascular health and cognition? Results of the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) study

BACKGROUND AND PURPOSE

Few studies have assessed the role of vitamin D in the association between cardiovascular risk factors and cognitive function. Here, the aim was to investigate the association between cardiovascular health (CVH) and cognitive function according to vitamin D level in a middle-aged Korean population.

METHODS

This cross-sectional study included 840 men and 1811 women (mean age 57.2 years) from the Cardiovascular and Metabolic Diseases Etiology Research Center study baseline enrolment (2013-2018). Life's Simple 7 tools from the American Heart Association were used to assess CVH. Cognitive function was evaluated using the Mini-Mental State Estimation for Dementia Screening (MMSE-DS), and the serum 25-hydroxyvitamin D level was measured.

RESULTS

In the adjusted generalized linear regression models, no significant association between a high Life's Simple 7 score (4-7 metric at optimal level) and MMSE-DS score (β = 0.01, P = 0.93) was found. Amongst men with a high vitamin D level, the high Life's Simple 7 score group showed a significantly higher MMSE-DS score (β = 0.48, P = 0.03). However, amongst men in the low vitamin D group, the association was opposite with no statistical significance (β = -0.23, P = 0.08). In women, the results were similar, but both strata according to vitamin D level showed no statistical significance.

CONCLUSIONS

Our findings suggest that vitamin D is an effect modifier in the association between CVH and cognition, especially in men.

Abstract P5-07-10: The prognostic significance of estrogen formation as a consequence of aromatase expression in tumor microenvironment

Estrogen synthesis via aromatase in adipose tissue has an important role in progression of postmenopausal breast cancer. The increased local concentrations of estrogen in breast cancer via aromatase overexpression within the tumor tissue have been demonstrated by some investigators. Although aromatase inhibitor is the standard endocrine therapy for postmenopausal breast cancer patients, it is not uncommon for patients to have poor compliance to the drugs due to their side effects. This research is based on the hypothesis that if aromatase expression is related to prognosis and if therapeutic effect varies depending on the degree of aromatase expression, then this study may be able to suggest a new guideline in terms of choosing between aromatase inhibitors and tamoxifen.

Methods: 154 postmenopausal breast cancer patients who underwent surgery and aromatase inhibitor therapy in Busan Paik Hospital, Inje University from January 2005 to December 2010 were enrolled. Patients with DCIS or stage IV breast cancer were excluded. Patients' clinicopathological data were collected and TMA blocks were created for immunohistochemistry studies to examine aromatase expression.

Results: The recurrence has occured in 7 patients (6.9%). Stage, tumor size and number of lymph node metastasis were related to increased risk of recurrence (p=0.051, 0.043, 0.001). The aromatase expression in cancer cells had significant correlation with clinical stage (p=0.041). There was also a positive correlation between Ki67 and aromatase expression in cancer tissue (p=0.006). However, aromatase expression in cancer, stromal, and adipose tissue had no relationship with recurrence (p=0.410, 0.627, 0.552).

Correlation between clinicopathologic factors and aromatase expression (Linear by linear association and Spearman's correlation coefficient test)Site of aromatase expressionERPRKi67P53BMIStageIn Cancer0.6060.5920.0060.4510.9560.041In Stroma0.2200.4710.5840.3290.3670.229In Adipose0.9880.2650.1590.1170.7701.000

Conclusions: Aromatase expression in cancer cells was correlated with clinical stage. This implies that aromatase expression might have a role of prognostic marker in addition to role of treatment indicator. There was no direct correlation between aromatase expression and recurrence.

Citation Format: Kim TH, Lee A, Han JW, Jung SJ, Byun K-D. The prognostic significance of estrogen formation as a consequence of aromatase expression in tumor microenvironment [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-07-10.

Efficacy and safety of a non-mineral oil adjuvanted injectable vaccine for the protection of Atlantic salmon (Salmo salar L.) against Flavobacterium psychrophilum

Flavobacterium psychrophilum is the causative agent of Rainbow Trout Fry Syndrome which has had a major impact on global salmonid aquaculture. Recent outbreaks in Atlantic salmon in Scotland and Chile have added to the need for a vaccine to protect both salmon and trout. At present no licensed vaccines are available in Europe, leaving antibiotics as the only course of action to contain disease outbreaks. Outbreaks generally occur in fry at temperatures between 10 and 15 °C. Recently outbreaks in larger fish have given added impetus to the development of a vaccine which can provide long term protection from this highly heterogeneous pathogen. Most fish injectable vaccines are formulated with oil emulsion adjuvants to induce strong and long lasting immunity, but which are known to cause side effects. Alternative adjuvants are currently sought to minimise these adverse effects. The current study was performed to assess the efficacy of a polyvalent, whole cell vaccine containing formalin-inactivated F. psychrophilum to induce protective immunity in Atlantic salmon. The vaccine was formulated with an adjuvant containing squalene and aluminium hydroxide, and was compared to a vaccine formulated with a traditional oil adjuvant, Montanide ISA 760VG, and a non-adjuvanted vaccine. Duplicate groups of salmon (23.5 ± 6.8 g) were vaccinated with each of the vaccine formulations or phosphate buffered saline by intraperitoneal injection. Fish were challenged by intramuscular injection with F. psychrophilum six weeks post-vaccination to test the efficacy of the vaccines. Cumulative mortality reached 70% in the control salmon, while the groups of salmon that received vaccine had significantly lower mortality than the controls (p = 0.0001), with no significant difference in survival between vaccinated groups. The squalene/alum adjuvant was safe, more readily metabolised by the fish and induced less histopathological changes than the traditional oil adjuvant.

Application of calcium oxide (CaO, heated scallop-shell powder) for the reduction of Listeria monocytogenes biofilms on eggshell surfaces

This study investigated bactericidal activity of 0.05 to 0.50% calcium oxide (CaO) against planktonic cells in tryptic soy broth (TSB) and biofilms of Listeria monocytogenes on eggshell surfaces. The bactericidal activity of CaO against planktonic cells and biofilms of L. monocytogens significantly (P < 0.05) increased log reductions with increasing concentrations of CaO. Exposure to 0.05 to 0.50% CaO for one min reduced planktonic cells in TSB cell suspensions by 0.47 to 3.86 log10CFU/mL and biofilm cells on the shell surfaces by 0.14 to 2.32 log10CFU/cm2. The Hunter colors of eggshells ("L" for lightness, "a" for redness, and "b" for yellowness), shell thickness (puncture force), and sensory quality (egg taste and yolk color) were not changed by 0.05 to 0.50% CaO treatment. The nonlinear Weibull model was used to calculate CR = 3 values as the CaO concentration of 3 log (99.9%) reduction for planktonic cells (R2 = 0.96, RMSE = 0.26) and biofilms (R2 = 0.95, RMSE = 0.18) of L. monocytogens. The CR = 3 value, 0.31% CaO for planktonic cells, was significantly (P < 0.05) lower than 0.57% CaO for biofilms. CaO could be an alternative disinfectant to reduce planktonic cells and biofilms L. monocytogenes on eggshell surface in egg processing plants.

Low pathogenicity of flounder iridovirus (FLIV) and the absence of cross-protection between FLIV and rock bream iridovirus

The genus Megalocytivirus is known to infect a wide range of cultured marine fish. In this study, we examined the pathogenicity of FLIV (Megalocytivirus from olive flounder, genotype III) and RBIV (Megalocytivirus from rock bream, genotype I) to their homologous and heterologous host species. Olive flounder (7.5 ± 1.3 cm) injected with FLIV [major capsid protein (MCP) gene copies, 6.8 × 10³ -6.5 × 10⁶ /fish] at 24 °C did not die until 90 days post-infection (dpi). The average virus replication in the spleen peaked (1.27 × 10⁶ /fish) at 20 dpi. Rock bream (6.5 ± 1.5 cm) injected with FLIV (8.8 × 10⁵ and 6.5 × 10⁶ /fish of MCP copies) showed no mortality until 50 dpi. The rock bream that survived after FLIV infection were rechallenged with RBIV at 50 dpi had 100% mortality, showing that there is no cross-protection between FLIV and RBIV. Temperature shifting (26 °C and 20 °C at 12 h intervals) did not cause FLIV-specific mortality into olive flounder, but higher virus copies were observed in the fish exposed to higher stocking density. This study demonstrates that FLIV and RBIV have different antigenic and pathogenic characteristics and that FLIV has low pathogenicity to olive flounder.

Extracellular ATP Induces Calcium Signaling in Odontoblasts

Odontoblasts form dentin at the outermost surface of tooth pulp. An increasing level of evidence in recent years, along with their locational advantage, implicates odontoblasts as a secondary role as sensory or immune cells. Extracellular adenosine triphosphate (ATP) is a well-characterized signaling molecule in the neuronal and immune systems, and its potential involvement in interodontoblast communications was recently demonstrated. In an effort to elaborate the ATP-mediated signaling pathway in odontoblasts, the current study performed single-cell reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescent detection to investigate the expression of ATP receptors related to calcium signal in odontoblasts from incisal teeth of 8- to 10-wk-old rats, and demonstrated an in vitro response to ATP application via calcium imaging experiments. While whole tissue RT-PCR analysis detected P2Y₂, P2Y₄, and all 7 subtypes (P2X₁ to P2X₇) in tooth pulp, single-cell RT-PCR analysis of acutely isolated rat odontoblasts revealed P2Y₂, P2Y₄, P2X₂, P2X₄, P2X₆, and P2X₇ expression in only a subset (23% to 47%) of cells tested, with no evidence for P2X₁, P2X₃, and P2X₅ expression. An increase of intracellular Ca²⁺ concentration in response to 100μM ATP, which was repeated after pretreatment of thapsigargin or under the Ca²⁺-free condition, suggested function of both ionotropic and metabotropic ATP receptors in odontoblasts. The enhancement of ATP-induced calcium response by ivermectin and inhibition by 5-(3-bromophenyl)-1,3-dihydro-2H-benzofuro[3,2-e]-1,4-diazepin-2-one (5-BDBD) confirmed a functional P2X₄ subtype in odontoblasts. Positive calcium response to 2',3'-O-(benzoyl-4-benzoyl)-ATP (BzATP) and negative response to α,β-methylene ATP suggested P2X₂, P2X₄, and P2X₇ as functional subunits in rat odontoblasts. Single-cell RT-PCR analysis of the cells with confirmed calcium response and immunofluorescent detection further corroborated the expression of P2X₄ and P2X₇ in odontoblasts. Overall, this study demonstrated heterogeneous expression of calcium-related ATP receptor subtypes in subsets of individual odontoblasts, suggesting extracellular ATP as a potential signal mediator for odontoblastic functions.

Effects of water temperature on mortality in Megalocytivirus-infected rock bream Oplegnathus fasciatus (Temminck et Schlegel) and development of protective immunity

Rock bream iridovirus (RBIV) causes huge losses, especially in rock bream Oplegnathus fasciatus. Rock bream injected with RBIV and held at 29, 26, 23 or 20 °C had 100% mortality. Conversely, all infected fish held at 17 °C survived even after the temperature was progressively increased to 26 °C at 100 dpi. Rock bream exposed to virus and held for 2, 4 and 7 days at 23/26 °C before the temperature was reduced to 17 °C had mortality rates of 26.6/73.2%, 66.6/100% and 93.4/100%, respectively, through 100 dpi. When surviving fish had the water temperature increased from 17 to 26 °C at 100 dpi, they did not exhibit signs of disease and had low virus copy numbers (below 10(3)). To investigate the development of a protective immune, rock bream were infected with RBIV and held at 23 °C before shifting the water temperature to 17 °C at 4 dpi. All injected fish survived until 120 dpi. While 100% of the previously unexposed fish died, 80.2% of the previously infected fish survived. When the survivors were rechallenged again at 160 dpi, no further mortality occurred. The high survival rate of fish following rechallenge with RBIV indicates that protective immunity was established in the surviving rock bream.

Improved methods for selective cryolipolysis results in subcutaneous fat layer reduction in a porcine model

BACKGROUND/AIMS

Cryolipolysis is a noninvasive method for the selective reduction of localized fat tissues. It has demonstrated efficacy in both clinical and preclinical trials; however, despite its popularity, its mechanisms of action and evaluation methods are not yet fully defined. The purpose of this study was to improved methods for cryolipolysis using a porcine model.

METHODS

The abdomens of female PWG micro-pigs were treated with a cooling device (CRYOLIPO II(™)), and we examined the treatment effects using photography, three-dimensional photography, ultrasound, gross, and microscopic pathology, and serum lipid level analyses in order to determine the mechanism of action, efficacy, and safety of CRYOLIPO II(™).

RESULTS

CRYOLIPO II(™) successfully reduced abdominal fat in our porcine model. Gross and microscopic histological results confirmed the noninvasive cold-induced selective subcutaneous fat destruction, and showed increases in pre-adipocyte differentiation and in the activation of lipid catabolism. In particular, we found that CRYOLIPO II(™) may increase PPARδ (delta) levels in adipose tissue at 30-60 days post-treatment.

CONCLUSION

Fat reduction by cryolipolysis was successfully achieved in our porcine model. Thus, our findings indicate that CRYOLIPO II(™) may be a promising fat reduction device for body contouring and fat reduction in humans, and that cryolipolysis exerts its effects, at least partly, by targeting the PPARδ signaling pathway. These results show that both investigative and diagnostic potentials capacity.

Activation of transient receptor potential ankyrin 1 by eugenol

Eugenol is a bioactive plant extract used as an analgesic agent in dentistry. The structural similarity of eugenol to cinnamaldehyde, an active ligand for transient receptor potential ankyrin 1 (TRPA1), suggests that eugenol might produce its effect via TRPA1, in addition to TRPV1 as we reported previously. In this study, we investigated the effect of eugenol on TRPA1, by fura-2-based calcium imaging and patch clamp recording in trigeminal ganglion neurons and in a heterologous expression system. As the result, eugenol induced robust calcium responses in rat trigeminal ganglion neurons that responded to a specific TRPA1 agonist, allyl isothiocyanate (AITC), and not to capsaicin. Capsazepine, a TRPV1 antagonist failed to inhibit eugenol-induced calcium responses in AITC-responding neurons. In addition, eugenol response was observed in trigeminal ganglion neurons from TRPV1 knockout mice and human embryonic kidney 293 cell lines that express human TRPA1, which was inhibited by TRPA1-specific antagonist HC-030031. Eugenol-evoked TRPA1 single channel activity and eugenol-induced TRPA1 currents were dose-dependent with EC50 of 261.5μM. In summary, these results demonstrate that the activation of TRPA1 might account for another molecular mechanism underlying the pharmacological action of eugenol.

Cellular and molecular mechanisms of dental nociception

Due, in part, to the unique structure of the tooth, dental pain is initiated via distinct mechanisms. Here we review recent advances in our understanding of inflammatory tooth pain and discuss 3 hypotheses proposed to explain dentinal hypersensitivity: The first hypothesis, supported by functional expression of temperature-sensitive transient receptor potential channels, emphasizes the direct transduction of noxious temperatures by dental primary afferent neurons. The second hypothesis, known as hydrodynamic theory, attributes dental pain to fluid movement within dentinal tubules, and we discuss several candidate cellular mechanical transducers for the detection of fluid movement. The third hypothesis focuses on the potential sensory function of odontoblasts in the detection of thermal or mechanical stimuli, and we discuss the accumulating evidence that supports their excitability. We also briefly update on a novel strategy for local nociceptive anesthesia via nociceptive transducer molecules in dental primary afferents with the potential to specifically silence pain fibers during dental treatment. Further understanding of the molecular mechanisms of dental pain would greatly enhance the development of therapeutics that target dental pain.

Antinociceptive curcuminoid, KMS4034, effects on inflammatory and neuropathic pain likely via modulating TRPV1 in mice

BACKGROUND

Curcumin, the active ingredient of turmeric (Curcuma longa), has a wide range of beneficial effects including anti-inflammation and analgesia. However, poor bioavailability of curcumin hinders its clinical application. To overcome this limitation, we modified the structure of curcumin and synthesized new derivatives with favourable pharmacokinetic profiles. Recently, curcumin has been shown to have an antagonizing effect on transient receptor potential vanilloid type 1 (TRPV1) ion channels. We investigated the antinociceptive activity of KMS4034 which had the most favourable pharmacokinetics among the tested curcumin derivatives.

METHODS

To evaluate the mechanism of the antinociceptive effects of KMS4034, capsaicin (I(CAP))- and heat (I(heat))-induced currents in TRPV1 expressing HEK293 cells were observed after the application of KMS4034. Nociceptive behavioural measurement using the hot-plate test, formalin test, and chronic constriction injury (CCI) model were evaluated in mice. Also, calcitonin gene-related peptide (CGRP) was stained immunohistochemically in the L4/5 dorsal horns in mice with neuropathic pain.

RESULTS

I(CAP) (P<0.01) and I(heat) (P<0.05) of TRPV1 were significantly blocked by 10 μM KMS4034. Behaviourally, noticeable antinociceptive effects after 10 mg kg(-1) of KMS4034 treatment were observed in the first (P<0.05) and second phases (P<0.05) of the formalin and hot-plate tests. The mechanical threshold of CCI mice treated with 10 mg kg(-1) KMS4034 was significantly increased compared with control. Immunohistochemical CGRP expression was decreased in the lamina I-II of the lumbar dorsal horns in KMS4034-treated CCI mice compared with the control (P<0.05).

CONCLUSIONS

KMS4034 may be an effective analgesic for various pain conditions.

Long-term clinical outcomes and risk factors for the occurrence of post-operative complications after cardiovascular surgery in patients with Behçet's disease

OBJECTIVES

Cardiovascular surgery in patients with Behçet's disease (BD) frequently leads to postoperative complications such as anastomotic leakage, occlusion or pseudoaneurysm. We evaluated the clinical outcomes and related risk factors of postoperative complications in BD patients undergoing cardiovascular surgeries, as well as the long-term efficiency of postoperative immunosuppressive treatment.

METHODS

Forty-one patients with BD who had undergone cardiovascular surgery between 1990 and 2009 were studied. We evaluated the patients' clinical data, postoperative complications, and survival rate. Risk factors related to the occurrence of postoperative complications were identified by univariate analysis using the Kaplan-Meier method with the log-rank test and multivariate analysis using the Cox proportional hazards regression model.

RESULTS

Fifty-nine operations were performed in 41 patients. During the mean follow-up period of 65.3±48.1 months, complications such as paravalvular leakage, dehiscence, fistula, graft occlusion, or pseudoaneurysm occurred in 29 operations (49.2%). The cumulative occurrence rate of postoperative complication was 10.2% at three months, 32.8% at 12 months, and 43.8% at 24 months. Upon univariate analysis, young age, high Creactive protein levels, lack of postoperative immunosuppression, and short disease duration were identified as significant factors responsible for the occurrence of postoperative complications. In multivariate analysis, postoperative immunosuppression was found to independently lower the risk of complications. The 5-year survival rate was significantly higher in patients with postoperative immunosup immunosuppression than in those without (84.5% vs. 45.0%, p=0.011).

CONCLUSIONS

The present study suggests that postoperative immunosuppressive therapy after cardiovascular surgeries in BD patients is important for reducing the development of serious postoperative complications.

Ultrasound-based diagnostic classification for solid and partially cystic thyroid nodules

BACKGROUND AND PURPOSE

The ability of US to differentiate benign thyroid nodules from malignant ones is still a matter of debate. The aim of this study was to assess the diagnostic efficacy of a US-based classification system for solid and PCTNs through a prospectively designed study.

MATERIALS AND METHODS

We studied 1289 thyroid nodules in 1036 patients who underwent thyroid US, US-FNA, and thyroid surgery. Each thyroid nodule was prospectively classified into 1 of 5 diagnostic categories following real-time US examination: benign, probably benign, borderline, possibly malignant, and malignant. Solid nodules were classified by using all 5 categories, and PCTNs were classified by all except the borderline category. We calculated the diagnostic efficacy of thyroid US by comparing US diagnoses with histopathologic results of surgically resected thyroid nodules.

RESULTS

One thousand fifty-five solid nodules and 234 PCTNs were prospectively classified as benign (n = 435 and 179), probably benign (n = 213 and 25), borderline (n = 94 and 0), possibly malignant (n = 115 and 15), and malignant (n = 198 and 15), respectively. Of these 1289 nodules, 505 were surgically resected and confirmed by pathology (191 benign and 314 malignant nodules); there were 44 resected solid nodules with a borderline category. For solid nodules and PCTNs, the sensitivity, specificity, positive and negative predictive values, and accuracy of US diagnosis were 86.1 and 66.7, 90.0 and 88.9, 94.3 and 75.0, 77.3 and 84.2, and 87.5% and 81.5%, respectively, based on 505 surgical specimens and excluding the 42 solid borderline nodules.

CONCLUSIONS

Our US-based classification system can provide helpful guidance for the management of thyroid nodules.

Role of sonographic diagnosis in managing Bethesda class III nodules

BACKGROUND AND PURPOSE

Bethesda class III cytology is an important limitation of the US-FNA in assessing thyroid nodules. This study aimed to assess the diagnostic efficacy of US in evaluating thyroid nodules with Bethesda class III cytology.

MATERIALS AND METHODS

From January 2008 to December 2009, 1036 patients with 1289 thyroid nodules diagnosed by US and subsequent US-FNA biopsy were enrolled in the study. On the basis of US features, each thyroid nodule was prospectively classified by a single radiologist into 1 of 5 diagnostic categories: benign, probably benign, borderline, possibly malignant, and malignant. Solid nodules were classified by using all 5 categories, whereas partially cystic nodules were classified by using 4 (borderline was omitted). We calculated the diagnostic efficacy of thyroid US by comparing the US diagnoses with the histopathology results of Bethesda class III nodules.

RESULTS

Of the 51 Bethesda class III nodules, 35 were surgically confirmed and 8 were histologically diagnosed, and a malignancy rate of 46.5% (20/43) was determined. From the 43 nodules, the sensitivity, specificity, positive and negative predictive values, and accuracy were calculated with 9 borderline nodules excluded (100%, 94.7%, 93.3%, 100%, and 97.0%, respectively) and with the 9 when reclassified as benign (63.6%, 95.2%, 93.3%, 71.4%, and 79.1%, respectively) and malignant (100%, 85.7%, 88.0%, 100%, and 93.0%, respectively). The values obtained with exclusion and malignancy reclassification of 9 borderline nodules were not significantly different (P = .250).

CONCLUSIONS

US diagnosis by using the present US classification system can be helpful for managing Bethesda class III nodules.

Atypical Aeromonas salmonicida infection in the black rockfish, Sebastes schlegeli Hilgendorf, in Korea

Cultured black rockfish, Sebastes schlegeli, suffered mass mortalities during winter 2008 and spring 2009 in Korea, showing clinical signs of ulcer lesions and haemorrhages over their body surface. The aetiological agent was identified as Aeromonas salmonicida (strains RFAS-1, -2 and -3), which is a non-pigmented, slow-growing bacterium. Phenotypes of RFAS strains showed variation, while 16S rRNA, gyrB, rpoD, dnaJ and recA gene sequences of all the strains were affiliated to A. salmonicida. In particular, vapA gene sequences of the strains were most closely related to one of the five subspecies of A. salmonicida subsp. masoucida (=KCCM 40239(T) ). LD(50) values of RFAS-1 for intraperitoneal and intramuscular injection were 1.5 × 10(5.25) and 1.5 × 10(6.4) cfu/rockfish, respectively. However, A. salmonicida strains KCCM 40239(T) and SAS-1, which originate from masou and chum salmon, respectively, were not pathogenic to black rockfish. RFAS strains, possessing A-layer protein on their surface, exhibited β-haemolytic activity against rockfish erythrocytes and capability to survive in rockfish serum, which seem to be associated with virulence.

Substance P sensitizes P2X3 in nociceptive trigeminal neurons

Peripheral inflammation produces pain hypersensitivity by sensitizing nociceptors. Potentiation of P2X3 receptor activity in nociceptors may play an important role in this peripheral sensitization. However, we do not fully understand how P2X3 activity is elevated in inflammation. Thus, we investigated whether P2X3 activity in trigeminal nociceptive neurons is regulated by the neurokinin-1 (NK-1) receptor that is activated by an inflammatory mediator, substance P. Single-cell RT-PCR and immunohistochemistry revealed that NK-1 in nociceptive neurons was mainly co-expressed with P2X3. Ca(2+) imaging and whole-cell patch-clamp recordings indicated that both substance P and Sar-substance P, a selective NK-1 agonist, significantly potentiated α,β-meATP-induced currents and [Ca(2+)](i) responses in nociceptive neurons. These potentiating effects were completely blocked by GR82334, a specific NK-1 antagonist. Our results demonstrate that substance P sensitizes P2X3 receptor through the activation of NK-1, thus warranting these receptors as possible targets for pain therapy in the orofacial region.

ABBREVIATIONS

α,β-methylene adenosine 5'-triphosphate (ATP), α,β-meATP; neurokinin-1, NK-1; single-cell reverse-transcription polymerase chain-reaction, single-cell RT-PCR; [Sar(9),Met(O(2))(11)]-substance P, Sar-substance P.

Sonographic differentiation of asymptomatic diffuse thyroid disease from normal thyroid: a prospective study

BACKGROUND AND PURPOSE

There is no useful guide or study related to the differentiation of asymptomatic diffuse thyroid disease from normal thyroid by using thyroid US. This study was prospectively designed to evaluate the efficacy of the use of real-time thyroid sonography as performed by an experienced radiologist for the identification of asymptomatic DTD.

MATERIALS AND METHODS

From January 2008 to December 2008, 2267 patients underwent thyroid sonography in our hospital by 1 radiologist. Each patient's thyroid was prospectively classified as being in 1 of 4 of the following diagnostic categories on the basis of the sonographic features as determined with the use of real-time sonography: suggestive for DTD, suspicious for DTD, indeterminate, and no evidence of DTD. We calculated the diagnostic efficacy of the sonographic classifications compared with the pathology results.

RESULTS

Sonographic classifications for DTD in 340 patients who underwent thyroid surgery because of thyroid malignancy or other causes included the following: suggestive for DTD (n = 32), suspicious for DTD (n = 39), indeterminate (n = 18), and no evidence of DTD (n = 251). On the pathology, HT (n = 33), chronic lymphocytic thyroiditis (n = 27), diffuse hyperplasia (n = 2), and NTP (n = 278) were identified. There were true-positive cases (n = 50), true-negative cases (n = 244), false-positive cases (n = 21), and false-negative cases (n = 7). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for a diagnosis of asymptomatic DTD were 87.7%, 92.1%, 70.4%, 97.2%and 91.3%, respectively.

CONCLUSIONS

The present sonographic classification based on real-time sonography of the thyroid is a useful tool for differentiating asymptomatic DTD from normal thyroid.

Tunic morphology and viral surveillance in diseased Korean ascidians: Soft tunic syndrome in the edible ascidian, Halocynthia roretzi (Drasche), in aquaculture

'Soft tunic syndrome' causes mass mortality in the edible ascidian Halocynthia roretzi in Korean and Japanese aquaculture. In histopathological comparison, there were no specific differences between diseased specimens from Korea and Japan, indicating that soft tunic syndrome occurring in Korea and Japan is the same disease. No bacterial or protozoan cells were microscopically detected in either healthy or diseased tunics suggesting they are not the direct causes of soft tunic syndrome. Attempts were made to isolate virus from affected ascidians taking into account temperature conditions in which soft tunic syndrome is most prevalent in the field. However, no viruses were isolated from diseased or non-diseased specimens using chinook salmon embryo (CHSE-214), flounder fin (FFN) or epithelioma papillosum cyprini (EPC) cell lines.

Antigenic differences of the scuticociliate Miamiensis avidus from Japan

In Japan and Korea, outbreaks of scuticociliatosis have frequently occurred in Japanese flounder, Paralichthys olivaceus. Morphological observations and small subunit rRNA gene sequences have shown that the causative agent of scuticociliatosis in the flounder is Miamiensis avidus (syn. Philasterides dicentrarchi). In this study, we elucidated the antigenic differences between six Japanese M. avidus isolates as an initial step toward developing an effective vaccine against the disease. Four Japanese flounder isolates (IyoI, Nakajima, JF05To and Mie0301 isolates), one spotted knifejaw, Oplegnathus punctatus, isolate (SK05Kyo), and one ridged-eye flounder, Pleuronichthys cornutus, isolate (RF05To) were subjected to serological analysis. Antisera against IyoI, SK05Kyo, Nakajima and Mie0301 isolates were raised in rabbits and used for immobilization assays and Western blotting. Immobilization assays showed that the six isolates could be divided into three groups, tentatively designated serotype I for IyoI, JF05To, RF05To, SK05Kyo, serotype II for Nakajima and serotype III for Mie0301. Western blotting results supported these three serotypes, with marked similarities in the banding profiles of IyoI, JF05To, RF05To and SK05Kyo isolates, which were distinct from the Nakajima and Mie0301 isolates. Three isolates, IyoI, Nakajima and Mie0301 that were selected as representatives of each serotype, were highly pathogenic to Japanese flounder by experimental infection. Based on these findings, we propose that there are at least three M. avidus serotypes in Japan.

Successful sonography-guided fine-needle aspiration biopsy of a 1-millimeter-diameter papillary thyroid microcarcinoma

A PTMC is defined as a thyroid papillary cancer that measures < or =10 mm in the greatest diameter. The detection rate for a PTMC has increased because of the worldwide use of high-resolution sonography and US-FNAB. We report a case of a 1-mm-diameter PTMC confirmed at thyroidectomy for which the cytologic diagnosis had an important role in deciding the extent of surgery (ie, either a total thyroidectomy or a hemithyroidectomy).

Lymphocystis disease virus persists in the epidermal tissues of olive flounder, Paralichthys olivaceus (Temminch & Schlegel), at low temperatures

Olive flounder artificially infected with lymphocystis disease virus (LCDV) were reared at 10, 20 and 30 degrees C for 60 days, to compare LCD-incidence. In the fish reared at 20 degrees C, lymphocystis cells appeared on the skin and fins at 35 days post-challenge, and the cumulative LCD-incidence was 80% at 60 days. High levels of LCDV, with a mean polymerase chain reaction (PCR) titre of 10(6) PCR-U mg(-1) tissue, were detected in the fins and skin of LCD-affected fish at 20 degrees C, but were not detected in the spleen, kidney, brain and intestinal tissues of these fish. No LCD clinical signs were observed in the fish reared at 10 degrees C and 30 degrees C; however, a low level of LCDV (10(3) PCR-U mg(-1) tissue) was detected in the fins and skin of these fish. By increasing the rearing temperature from 10 to 20 degrees C, lymphocystis clusters appeared on the skin and fins of the fish with no previous LCD clinical signs within 33 days after the temperature change. It was shown that permissive cells for LCDV infection exist in the epidermis of olive flounder. At low temperatures, small amounts of LCDV were able to persist over a period extended for a further 45 days in the fish epidermis, even though the fish showed no LCD clinical signs. The optimum growth temperature of LCDV is near 20 degrees C.

Modulation of CaV2.3 calcium channel currents by eugenol

Eugenol, a natural congener of capsaicin, is a routine analgesic agent in dentistry. We have recently demonstrated the inhibition of Ca(V)2.2 calcium channel and sodium channel currents to be molecular mechanisms underlying the analgesic effect of eugenol. We hypothesized that Ca(V)2.3 channels are also modulated by eugenol and investigated its mode of action using the whole-cell patch-clamp technique in a heterologous expression system. Eugenol inhibited calcium currents in the E52 cell line, stably expressing the human Ca(V)2.3 calcium channels, where TRPV1 is not endogenously expressed. The extent of current inhibition was not significantly different between naïve E52 cells and TRPV1-expressing E52 cells, suggesting no involvement of TRPV1. In contrast, TRPV1 activation is prerequisite for the inhibition of Ca(V)2.3 calcium channels by capsaicin. The results indicate that eugenol has mechanisms distinct from those of capsaicin for modulating Ca(V)2.3 channels. We suggest that inhibition of Ca(V)2.3 channels by eugenol might contribute to its analgesic effect.

Eugenol inhibits K+ currents in trigeminal ganglion neurons

Eugenol, a natural capsaicin congener, is widely used in dentistry. Eugenol inhibits voltage-activated Na(+) and Ca(2+) channels in a transient receptor potential vanilloid 1 (TRPV1)-independent manner. We hypothesized that eugenol also inhibits voltage-gated K(+) currents, and investigated this in rat trigeminal ganglion neurons and in a heterologous system using whole-cell patch clamping. Eugenol inhibited voltage-gated K(+) currents, and the inhibitory effects of eugenol were observed in both capsaicin-sensitive and capsaicin-insensitive neurons. Pre-treatment with capsazepine, a well-known antagonist of TRPV1, failed to block the inhibitory effects of eugenol on K(+) currents, suggesting no involvement of TRPV1. Eugenol inhibited human Kv1.5 currents stably expressed in Ltk(-) cells, where TRPV1 is not endogenously expressed. We conclude that eugenol inhibits voltage-gated K(+) currents in a TRPV1-independent manner. The inhibition of voltage-gated K(+) currents is likely to contribute to the irritable action of eugenol.

ABBREVIATIONS

human Kv1.5 channel, hKv1.5; transient receptor potential vanilloid 1, TRPV1.

Eugenol inhibits sodium currents in dental afferent neurons

Although eugenol is widely used in dentistry, little is known about the molecular mechanisms responsible for its anesthetic properties. In addition to calcium channels, recently demonstrated by our group, there could be another molecular target for eugenol. Using a whole-cell patch-clamp technique, we investigated the effect of eugenol on voltage-gated sodium channel currents (I(Na)) in rat dental primary afferent neurons identified by retrograde labeling with a fluorescent dye in maxillary molars. Eugenol inhibited action potentials and I(Na) in both capsaicin-sensitive and capsaicin-insensitive neurons. The pre-treatment with capsazepine, a competitive antagonist of transient receptor potential vanilloid 1 (TRPV1), failed to block the inhibitory effect of eugenol on I(Na), suggesting no involvement of TRPV1. Two types of I(Na), tetrodotoxin (TTX)-resistant and TTX-sensitive I(Na), were inhibited by eugenol. Our results demonstrated that eugenol inhibits I(Na) in a TRPV1-independent manner. We suggest that I(Na) inhibition by eugenol contributes to its analgesic effect.

Susceptibility of marine fish species to a megalocytivirus, turbot iridovirus, isolated from turbot, Psetta maximus (L.)

Turbot iridovirus (TBIV), a member of the genus Megalocytivirus in the family Iridoviridae, was isolated from diseased turbot, Psetta maximus (L.), in Korea in 2003. In this study, experimental infection of turbot, Japanese flounder, Paralichthys olivaceus (Temminck & Schlegel), and rock bream, Oplegnathus fasciatus (Temminck & Schlegel), with TBIV was performed to evaluate the viral susceptibility of these fish species. After virus exposure, the mortalities of turbot reared at 22 and 25 degrees C were 60% and 100%, respectively, suggesting that TBIV is the causative agent of the mass mortality of turbot that occurred in Korea in 2003. Moreover, TBIV was detected in Japanese flounder and rock bream by polymerase chain reaction after experimental infection (26 days post-inoculation) despite no viral pathogenicity in these fish, suggesting that these two fish species are also susceptible to the virus. It is possible that horizontal transmission of TBIV occurs among these three fish species because turbot is routinely cultured with Japanese flounder and rock bream in Korea.

Incidence of dimethylacetamide induced hepatic injury among new employees in a cohort of elastane fibre workers

OBJECTIVE

To investigate the incidence of N,N-dimethylacetamide (DMA) induced hepatic injury among new elastane fibre workers and to explore factors relating to DMA induced hepatic injury.

METHODS

Elastane fibre workers exposed to DMA were monitored for hepatic injury. Four hundred and forty new workers employed from 1 January 2002 to 31 July 2004 were included as study subjects. DMA exposure estimates were based on urinary N-methylacetamide (NMA) concentrations.

RESULTS

There were 28 cases of DMA induced hepatic injury. The overall incidence of DMA induced hepatic injury among new elastane fibre workers was 0.089/person-year. Incidence rates were 7-10 times higher in high exposure groups than in low exposure groups. Fewer DMA induced hepatic injuries occurred among workers employed for a longer period. Workers whose exposure duration was more than seven months showed no hepatic injury in either the high or low exposure groups. Exposure category and duration of employment were significant variables in the multiple logistic regression analysis.

CONCLUSIONS

Results suggest the existence of dose dependent DMA induced hepatic injury. The inverse relation between the incidence of DMA induced hepatic injury and duration of employment may reflect a type of healthy survivor effect or tolerance to DMA induced hepatic injury.

Novel phase-matching condition for a four wave mixing experiment in an optical fiber

A new phase-matching condition for a four-wave-mixing (FWM) experiment in an optical fiber is proposed to simultaneously measure the linear and nonlinear optical properties of an optical fiber such as dispersion-zero wavelength, dispersion slop, and nonlinear refractive index. Several different dispersion shifted fibers (DSFs) and nonzero dispersion shifted fibers (NZDSFs) were tested to demonstrate the validity of our proposed method. We have also shown that experimental results are in good agreement with those obtained using a conventional measurement method. We believe that technique is a very powerful and efficient tool for zero-dispersion and dispersion slop mapping for already installed optical fibers.

A new genotype of lymphocystivirus, LCDV-RF, from lymphocystis diseased rockfish

Lymphocystis disease virus (LCDV) is the causative agent of lymphocystis disease. In this study, nucleotide sequences of the major capsid protein (MCP) gene were analyzed among LCDV isolates from Japanese flounder and rockfish. A phylogenetic tree revealed three clusters for lymphocystiviruses. The first cluster included Japanese flounder isolates; the second cluster consisted of rockfish isolates; and the remaining one consisted of LCDV-1. Nucleotide sequence identities were > or =99.6% among Japanese flounder isolates and 100% among rockfish isolates, while between each cluster they were < or =85.2%. Experimental infections with Japanese flounder and rockfish isolates revealed that Japanese flounder and rockfish were infected by the respective homologous isolate but not by the heterologous isolate. These findings suggest that at least three genotypes exist in the genus Lymphocystivirus.

Production of eleutherosides in in vitro regenerated embryos and plantlets of Eleutherococcus chiisanensis

High frequency somatic embryogenesis of Eleutheorcoccus chiisanensis was achieved through suspension culture of embryogenic cells in hormone-free Murashige and Skoog liquid medium supplemented with 30 g sucrose l-1. Cotyledonary somatic embryos were germinated and converted into plantlets using 20 microM: gibberellic acid which were then grown in a 10 l airlift bioreactor. HPLC analysis revealed the accumulation of eleutheroside B, E and E1 in the embryos and plantlets. Thus mass production of embryos and plantlets of E. chiisanensis can be achieved in liquid cultures and the biomass produced may become an alternative source of eleutherosides.

Enhanced post-germinative growth of encapsulated somatic embryos of Siberian ginseng by carbohydrate addition to the encapsulation matrix

This experiment was carried out to enhance conversion and ex vitro survival of encapsulated somatic embryos of Siberian ginseng (Eleutherococcus senticosus). Cotyledonary somatic embryos were encapsulated with 3.0% sodium alginate; 96% of the encapsulated embryos converted to plantlets with well-elongated epicotyls in Perlite containing sucrose as a carbon source. However, although they germinated, post-germinative growth of encapsulated embryos was suppressed on Perlite that did not contain sucrose. Instead of sucrose addition to Perlite, addition of carbon sources to the encapsulation matrix enhanced post-germinative growth of encapsulated embryos. In the encapsulation matrix with 2% sucrose, post-germinative growth of encapsulated embryos was more than twice (23.5%) that of the control capsules without sucrose (10.0%). Embryos encapsulated with both 2% sucrose and 1% starch powder showed the highest post-germinative growth percentage (42.1%). Iodine staining and analysis of starch content in the encapsulation matrix revealed that starch in the encapsulation matrix decomposed during embryo germination. This result indicates that carbohydrate treatment in the encapsulation matrix enhanced post-germinative growth of encapsulated embryos of Siberian ginseng.

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.

Synthesis of Si, Mg substituted hydroxyapatites and their sintering behaviors

Si, Mg-substituted hydroxyapatites, alone and co-substituted, have been prepared to obtain biomaterials having an improved biocompatibility. From FT-IR, XRD and ICP analyses, it was confirmed that single phases of hydroxyapatite substituted by Si alone or co-substituted by Si, Mg. The XRD data indicated the absence of extra phases related to silicon and magnesium oxide or other calcium phosphate species. Si-substituted hydroxyapatite of up to 2 wt% for Si and Si, Mg co-substituted hydroxyapatite of 1 wt% for the each ion keep their original structures intact for the sintering temperatures of up to 1200 degrees C. However, it is observed that ion substitutions by an amount higher than the above ratios for each hydroxyapatite lead to destabilization of original structures of the hydroxyapatite and to the production of tricalcium phosphate and calcium phosphate silicate phases when the samples were sintered at 1100 degrees C or higher.

Postsynaptic action mechanism of somatostatin on the membrane excitability in spinal substantia gelatinosa neurons of juvenile rats

We used tight-seal, whole-cell recording in juvenile rat spinal slices to investigate the action of somatostatin on substantia gelatinosa neurons. Bath application of somatostatin caused a robust and repeatable hyperpolarization or outward current in substantia gelatinosa neurons. Somatostatin inhibited spontaneous action potentials in subpopulation of substantia gelatinosa neurons. The amplitude of dorsal root-evoked excitatory postsynaptic currents and the frequency of spontaneous excitatory postsynaptic currents were not affected by somatostatin. The current induced by somatostatin developed almost instantaneously and did not show any time-dependent inactivation. The current-voltage relationship exhibited inward rectification. The conductance of somatostatin-sensitive current increased with the concentration of external K(+). The reversal potentials in different external K(+) concentrations were close to the K(+) equilibrium potentials. The effect of somatostatin was dose-dependent, with an EC(50) of 113 nM. The somatostatin-sensitive current was blocked by low concentration of extracellular Ba(2+) but not by glibenclamide, an inhibitor of ATP-sensitive K(+) channels. Hyperpolarization-activated cation current in a subpopulation of substantia gelatinosa neurons was not affected by somatostatin. In neurons recorded with an internal solution containing GTPgammaS, somatostatin induced outward current and hyperpolarization that did not reverse on washing. When the spontaneous induction of outward current with GTPgammaS was greatest, somatostatin did not induce any outward currents. Furthermore, intracellular dialysis of GDPbetaS, a G-protein antagonist, abolished the effect of somatostatin. In addition, SST-sensitive neurons were fewer in slices incubated with pertussis toxin than in adjacent control slices incubated without pertussis toxin. These results suggest that somatostatin decreases the postsynaptic membrane excitability of substantia gelatinosa neurons by a pertussis toxin-sensitive G-protein-mediated activation of an inwardly rectifying K(+) conductance.

Effects of capsaicin on Ca(2+) release from the intracellular Ca(2+) stores in the dorsal root ganglion cells of adult rats

We have investigated the effect of capsaicin on Ca(2+) release from the intracellular calcium stores. Intracellular calcium concentration ([Ca(2+)](i)) was measured in rat dorsal root ganglion (DRG) neurons using microfluorimetry with fura-2 indicator. Brief application of capsaicin (1 microM) elevated [Ca(2+)](i) in Ca(2+)-free solution. Capsaicin-induced [Ca(2+)](i) transient in Ca(2+)-free solution was evoked in a dose-dependent manner. Resiniferatoxin, an analogue of capsaicin, also raised [Ca(2+)](i) in Ca(2+)-free solution. Capsazepine, an antagonist of capsaicin receptor, completely blocked the capsaicin-induced [Ca(2+)](i) transient. Caffeine completely abolished capsaicin-induced [Ca(2+)](i) transient. Dantrolene sodium and ruthenium red, antagonists of the ryanodine receptor, blocked the effect of capsaicin on [Ca(2+)](i). However, capsaicin-induced [Ca(2+)](i) transient was not affected by 2-APB, a membrane-permeable IP(3) receptor antagonist. Furthermore, depletion of IP(3)-sensitive Ca(2+) stores by bradykinin and phospholipase C inhibitors, neomycin, and U-73122, did not block capsaicin-induced [Ca(2+)](i) transient. In conclusion, capsaicin increases [Ca(2+)](i) through Ca(2+) release from ryanodine-sensitive Ca(2+) stores, but not from IP(3)-sensitive Ca(2+) stores in addition to Ca(2+) entry through capsaicin-activated nonselective cation channel in rat DRG neurons.

Altered nociceptive response in mice deficient in the alpha(1B) subunit of the voltage-dependent calcium channel

Calcium influx through N-type calcium channels mediates synaptic transmission at numerous central synapses and transduces nociceptive information in the spinal dorsal horn. However, the precise role of N-type calcium channels in pain perception is not fully elucidated. To address this issue, we generated and analyzed knockout mice for alpha(1B,) the pore-forming subunit of the N-type calcium channel. Homozygous mutants are viable, fertile, and show normal motor coordination. In small-diameter dorsal root ganglion neurons from mutants the density of calcium channel currents is significantly reduced, which can be accounted for by the abolition of N-type currents. We performed several pain-related behavioral tests using the mutant mice. alpha(1B)-Deficient mice show reduced response to mechanical stimuli in the von Frey test and increased tail flick latency in response to radiant heat, indicating altered spinal reflexes. However, pain response in the hot plate test is normal. In the formalin paw test, the mutant mice exhibit significantly attenuated response in Phase 2, but normal pain behaviors in Phase 1. The response to visceral inflammatory pain caused by acetic acid is also reduced in alpha(1B) knockout mice. These results suggest that the alpha(1B) subunit of N-type calcium channel plays a major role in pain perception by acting at the spinal level, but not at the supraspinal level.

Voltage-dependent K(+) currents in spiral prominence epithelial cells of rat cochlea

It has been suggested that spiral prominence is associated with ion transport, but the characterization of ion channels has not been explored so far. We studied the electrical properties and ion conductances of the spiral prominence epithelial cells (SPECs), which are epithelial cells covering the luminal side of spiral prominence, in the upper turn of neonatal rat cochlea using a whole-cell variant patch clamp technique. The cell capacitance was 16.3+/-2.1 pF (n=33) and the resting membrane potential was -68. 9+/-2.5 mV (n=14) in perilymph-like bath solution. It was found that those SPECs possess a large voltage-activated, outwardly rectifying K(+) current and a small inwardly rectifying K(+) current. The outward K(+) current was activated by depolarizing pulses more positive than -30 mV, and sensitive to tetraethylammonium chloride (20 mM), 4-aminopyridine (10 mM), but not to Ba(2+) (0.5 mM). Tail current analysis revealed that it was primarily K(+)-selective. The time course of activation was well fitted by an exponential function raised to second power. The small inwardly rectifying K(+) current was sensitive to Ba(2+) (0.5 mM), and the Ba(2+)-sensitive current was K(+)-selective. In cell-attached or inside-out patch recordings, no discernible K(+) channel currents were found in the apical membrane of SPECs. Based on these results, we conclude that SPECs have two types of voltage-dependent K(+) currents, which are most likely located in the basolateral membrane.

Isolation of different types of birnavirus from ayu Plecoglossus altivelis and amago salmon Oncorhynchus rhodurus cultured in the same geographic area

A birnavirus was recently isolated from cultured ayu Plecoglossus altivelis on Shikoku island, Japan. The diseased fish displayed vertebral or vertical curvature and mild haemorrhage around the brain. Cytopathic effects (CPE) of the virus, including cell roundness, filamentous change and cell lysis, were observed in CHSE-214, RTG-2 and RSBK-2 cells. The virus isolated from ayu, designated the AY-98 strain, was found to be antigenically related to the marine birnavirus (MABV) Y-6 strain that originated from yellowtail Seriola quinqueradiata. AY-98 had a bi-segmented RNA genome and the same nucleotide sequence in the 310 bp VP2/NS junction as MABV Y-6. At the same time that the ayu epizootics occurred, another birnavirus (AM-98) was isolated from amago salmon Oncorhynchus rhodurus which were cultured 66 km away from the ayu farm. AM-98 showed a similar CPE and had the same host cell ranges as AY-98. However, AM-98 was serologically similar to the VR-299 strain of infectious pancreatic necrosis virus (IPNV) and their nucleotide sequences in the VP2/NS junction region showed 98% homology without changes at the amino acid level. In this study, the ayu strain AY-98 was grouped into MABV, whereas the amago salmon strain AM-98 was grouped into IPNV. This indicates that the 2 birnaviruses originated from different sources in spite of the fact that the places where they were isolated are close to one another. The results in this paper show a new aspect of the traditional consensus that the same serogroup of birnavirus distribute in close geographic areas.

Acute and prolonged toxicity to aquatic organisms of new and existing chemicals and pesticides

The relation of acute to prolonged toxicity of existing and new chemicals and active ingredients of numerous pesticides in the aquatic environment have been compared with their physico-chemical properties. The data had been presented to the authorities in behalf of the pesticide registrations, the notification of new chemicals or research projects. The ecotoxicity ratios are expressed as acute to prolonged ratios (APR). They are determined for fish and crustacea with existing and new chemicals and pesticides. In the case of the pesticides the data are subsummarized into fungicides, herbicides, insecticides. The variability of the APR is evaluated. According to the statistic evaluation of the data it must be summarized, that the toxic effects are often extremely specific and depend not only on the substance, but also on the aquatic species, the duration of the exposure, and the endpoint of the test. In general, a factor of 100 between the EC/LC50 of acute toxicity and NOEC of prolonged toxicity is scientifically justified. The data indicate that there is no significant correlation between lipophilic properties (logPow) or water solubility and toxicity in aquatic organisms. For that reason structure-activity relationships based on lipophilic properties of the substance cannot lead to reasonable results. It must be stated, that the prolonged ecotoxicity can not be exactly extrapolated from acute toxicity data on the basis of physico-chemical properties.

1,25(OH)2-16ene-vitamin D3 is a potent antileukemic agent with low potential to cause hypercalcemia

Compounds that induce cancer cells to differentiate are clinically effective for several types of malignancies. The 1,25-dihydroxyvitamin D3[1,25(OH)2D3(C)] induces leukemic cells, including HL-60, to differentiate and/or no longer proliferate, but it causes hypercalcemia. Development of vitamin D analogs that are more potent in their abilities to affect leukemic cells without causing greater hypercalcemia, may be useful therapeutically. A novel analog [1,25(OH)2-16ene-D3(HM)] has a double bond between C-16 and C-17; it appears to be an extremely effective antileukemic agent with the same or fewer effects on serum calciums. We define the potency of this compound and compare it with seven, previously reported, potent analogs of 1,25(OH)2D3. HM inhibited clonal growth of HL-60 cells by 50% at 1.5 x 10(-11) M. This was about equipotent to 1,25(OH)2-16ene-23yne-D3(V), about 100-fold more potent than many of the other analogs, and 1000-fold more potent than 1,25(OH)2D3. The rank order of leukemic inhibitory activity was: 1,25(OH)2-16ene-D3(HM) > or = 1,25(OH)2- 16ene-23yne-D3(V) > 1,25(OH)2-23ene-D3(EX) = 1,24(OH)2-22ene-24-cyclopropyl-D3(BT) = 22-oxa- 1,25(OH)2D3(EU) = 1,25(OH)2-24-homo-D3(ER) > 1,25(OH)2D3(C) > 1,25(OH)2-24- dihomo-D3(ES). The rank order of their effects on induction of differentiation of HL-60 cells, as measured by superoxide production and nonspecific esterase activity, was similar to their antiproliferative activities. In contrast, each analog slightly stimulated proliferation of normal human myeloid clonal growth. Serum calcium levels were the same or slightly less when either 1,25(OH)2-16ene-D3(HM) or 1,25(OH)2D3 (0.0625, 0.125, or 0.25 microgram) was given intraperitoneally to mice for 5 weeks. HM bound to 1,25(OH)2D3 receptors about 1.5-fold more avidly than 1,25(OH)2D3. In fact, this vitamin D3 appears to be the most avid binder to 1,25(OH)2D3 receptors that has been identified to date. In contrast, HM had a greater than 50-fold lower affinity for the D-binding proteins as compared with 1,25(OH)2D3, thus increasing the availability of the compound for target tissues. Further differentiation experiments showed that HM was more potent than 1,25(OH)2D3 in the presence of serum, but was equipotent in serum-free conditions. Taken together, our experiments suggest that 1,25(OH)2-16ene-D3(HM) may be more potent than 1,25(OH)2D3(C) because of its higher affinity to the 1,25(OH)2D3 receptors and its low affinity to the D-binding protein present in serum. HM is an ideal compound for clinical studies including patients with preleukemia and other neoplasia, as well as several skin disorders, such as psoriasis.